Science.gov

Sample records for cooling towers application

  1. State of the art cooling tower technology in geothermal power applications

    SciTech Connect

    Mortensen, K.P.

    1996-12-31

    Several cooling tower design configurations, including crossflow and counterflow, splash and film filled, have been used in geothermal applications over the years with varying degrees of longterm success. This paper examines the special water quality conditions expected in geothermal power generation, describes the current theory on materials and fill types most suitable for this application, and relates field experience to the theory. The goal is to arrive at current, but evolving {open_quotes}best practice{close_quotes} application rules for cooling tower designs in geothermal application. This means providing the most economically and thermally efficient cooling towers to end users, and having those selections provide good long-term system viability with reasonable maintenance practices.

  2. Cooling tower and plume modeling for satellite remote sensing applications

    SciTech Connect

    Powers, B.J.

    1995-05-01

    It is often useful in nonproliferation studies to be able to remotely estimate the power generated by a power plant. Such information is indirectly available through an examination of the power dissipated by the plant. Power dissipation is generally accomplished either by transferring the excess heat generated into the atmosphere or into bodies of water. It is the former method with which we are exclusively concerned in this report. We discuss in this report the difficulties associated with such a task. In particular, we primarily address the remote detection of the temperature associated with the condensed water plume emitted from the cooling tower. We find that the effective emissivity of the plume is of fundamental importance for this task. Having examined the dependence of the plume emissivity in several IR bands and with varying liquid water content and droplet size distributions, we conclude that the plume emissivity, and consequently the plume brightness temperature, is dependent upon not only the liquid water content and band, but also upon the droplet size distribution. Finally, we discuss models dependent upon a detailed point-by-point description of the hydrodynamics and thermodynamics of the plume dynamics and those based upon spatially integrated models. We describe in detail a new integral model, the LANL Plume Model, which accounts for the evolution of the droplet size distribution. Some typical results obtained from this model are discussed.

  3. COOLING TOWER PLUME MODEL

    EPA Science Inventory

    A review of recently reported cooling tower plume models yields none that is universally accepted. The entrainment and drag mechanisms and the effect of moisture on the plume trajectory are phenomena which are treated differently by various investigators. In order to better under...

  4. Legionella in cooling towers.

    PubMed

    Witherell, L E; Novick, L F; Stone, K M; Duncan, R W; Orciari, L A; Kappel, S J; Jillson, D A

    1986-01-01

    Legionellosis (Legionnaires' disease and Pontiac fever) outbreaks have been associated with aerosols ejected from contaminated cooling towers--wet-type heat rejection units (WTHRUs) used to dissipate unwanted heat into the atmosphere. The Vermont Department of Health undertook a program to inventory, inspect, and sample all WTHRUs in Vermont from April 1981 to April 1982. All WTHRUs were sampled for Legionella pneumophila and data were obtained for location, design, construction, and operating characteristics. Of the 184 WTHRUs operating, statistical analyses were performed on those 130 which were sampled for L. pneumophila only once during the study period. Of these, 11 (8.5%) were positive for L. pneumophila. Sources of makeup water and period of operation had significant association with the recovery of L. pneumophila. Five out of 92 towers (5.4%) utilizing surface water sources for cooling were positive for L. pneumophila, in contrast to 6 positive towers of the 38 units (15.8%) which obtained makeup water from ground water sources (p = .054 by chi-square test). Nearly 15% of the 54 units which operated throughout the year were positive, compared to less than 4% of the 76 towers operating seasonally (p = .03 by chi-square test). The mean pH of the cooling water in units where L. pneumophila was recovered (8.3) was significantly higher than the mean pH of 7.9 in units testing negative (p less than .05 by t-test). In addition, the mean log-transformed turbidity of positive towers, 0.03 nephelometric units (ntu), was significantly lower than the mean of log turbidity of negative towers, 0.69 ntu (p less than .02 by t-test). PMID:10281778

  5. Cooling tower hardware corrosion studies

    SciTech Connect

    Blue, S.C.

    1983-01-31

    The data presented in this report are interim results of a continuing investigation into the corrosion resistance of metals in the environment of a large cooling tower. Some of the significant observations are as follows: the corrosion of susceptible metals occurs most rapidly in the warm fog conditions between the deck and mist filters; the application of stainless steel must be made on the basis of alloy chemistry and processing history. Some corrosion resistant alloys may develop cracking problems after improper heat treating or welding; combinations of aluminum bronze, stainless steel, and silicon bronze hardware were not susceptible to galvanic corrosion; the service life of structural steel is extended by coal tar epoxy coatings; aluminum coatings appear to protect structural steel on the tower deck and below the distribution nozzles. The corrosion of cooling tower hardware can be easily controlled through the use of 316 stainless steel and silicon bronze. The use of other materials which exhibit general resistance should be specified only after they have been tested in the form of structural assemblies such as weldments and bolted joints in each of the different tower zones.

  6. PBF Cooling Tower. Hot deck of Cooling Tower with fan ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower. Hot deck of Cooling Tower with fan motors in place. Fan's propeller blades (not in view) rotate within lower portion of vents. Inlet pipe is a left of view. Contractor's construction buildings in view to right. Photographer: Larry Page. Date: June 30, 1969. INEEL negative no. 69-3781 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  7. Ozonation of cooling tower waters

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.; French, K. R.; Howe, R. D. (Inventor)

    1979-01-01

    Continuous ozone injection into water circulating between a cooling tower and heat exchanger with heavy scale deposits inhibits formation of further deposits, promotes flaking of existing deposits, inhibits chemical corrosion and controls algae and bacteria.

  8. Using ozone to treat cooling tower water

    SciTech Connect

    Webster, L.

    1995-07-01

    Ozone is a controversial but promising alternative to chemicals for treating water in cooling towers. A powerful disinfectant, ozone can prevent biofouling of heat exchange surfaces, and may mitigate scale and corrosion. Ozone treatment of cooling towers can cut costs for energy, water, sewage, and regulatory compliance. Ozone treatment is an electrotechnology, but ozone equipment represents only a small electric load. Although ozone has provided excellent results in some cooling tower applications, its effectiveness has not been proven conclusively. Less than 1,000 cooling towers use ozone water treatment in the United States. Acceptance of this technology is increasing, however, as indicated by its use by such large firms as IBM, AT and T, DuPont, and Xerox, and by its adoption by some chemical water treatment suppliers. The energy efficiency implications of ozone treatment are being researched. Southern California Edison found that in some systems, ozone treatment improved chiller efficiency up to 20 percent due to cleaner heat exchange surfaces.

  9. Technical Evaluation of Side Stream Filtration for Cooling Towers

    SciTech Connect

    2012-10-01

    Cooling towers are an integral component of many refrigeration systems, providing comfort or process cooling across a broad range of applications. Cooling towers represent the point in a cooling system where heat is dissipated to the atmosphere through evaporation. Cooling towers are commonly used in industrial applications and in large commercial buildings to release waste heat extracted from a process or building system through evaporation of water.

  10. Simple model of a cooling tower plume

    NASA Astrophysics Data System (ADS)

    Jan, Cizek; Jiri, Nozicka

    2016-06-01

    This article discusses the possibilities in the area of modeling of the so called cooling tower plume emergent at operating evaporating cooling systems. As opposed to recent publication, this text focuses on the possibilities of a simplified analytic description of the whole problem where this description shall - in the future - form the base of a calculation algorithms enabling to simulate the efficiency of systems reducing this cooling tower plume. The procedure is based on the application of basic formula for the calculation of the velocity and concentration fields in the area above the cooling tower. These calculation is then used to determine the form and the total volume of the plume. Although this approach does not offer more exact results, it can provide a basic understanding of the impact of individual quantities relating to this problem.

  11. Ozone Treatment For Cooling Towers

    NASA Technical Reports Server (NTRS)

    Blackwelder, Rick; Baldwin, Leroy V.; Feeney, Ellen S.

    1990-01-01

    Report presents results of study of cooling tower in which water treated with ozone instead of usual chemical agents. Bacteria and scale reduced without pollution and at low cost. Operating and maintenance costs with treatment about 30 percent of those of treatment by other chemicals. Corrosion rates no greater than with other chemicals. Advantage of ozone, even though poisonous, quickly detected by smell in very low concentrations.

  12. Cooling tower water conditioning study. [using ozone

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.; French, K. R.

    1979-01-01

    Successful elimination of cooling tower treatment chemicals was demonstrated. Three towers functioned for long periods of time with ozone as the only treatment for the water. The water in the systems was reused as much as 30 times (cycles of concentration) without deleterious effects to the heat exchangers. Actual system blow-down was eliminated and the only makeup water added was that required to replace the evaporation and mist entrainment losses. Minimum water savings alone are approximately 75.1 1/kg/year. Cost estimates indicate that a savings of 55 percent was obtained on the systems using ozone. A major problem experienced in the use of ozone for cooling tower applications was the difficulty of accurate concentration measurements. The ability to control the operational characteristics relies on easily and accurately determined concentration levels. Present methods of detection are subject to inaccuracies because of interfering materials and the rapid destruction of the ozone.

  13. 2004 Savannah River Cooling Tower Collection (U)

    SciTech Connect

    Garrett, Alfred; Parker, Matthew J.; Villa-Aleman, E.

    2005-05-01

    The Savannah River National Laboratory (SRNL) collected ground truth in and around the Savannah River Site (SRS) F-Area cooling tower during the spring and summer of 2004. The ground truth data consisted of air temperatures and humidity inside and around the cooling tower, wind speed and direction, cooling water temperatures entering; inside adn leaving the cooling tower, cooling tower fan exhaust velocities and thermal images taken from helicopters. The F-Area cooling tower had six cells, some of which were operated with fans off during long periods of the collection. The operating status (fan on or off) for each of the six cells was derived from operations logbooks and added to the collection database. SRNL collected the F-Area cooling tower data to produce a database suitable for validation of a cooling tower model used by one of SRNL's customer agencies. SRNL considers the data to be accurate enough for use in a model validation effort. Also, the thermal images of the cooling tower decks and throats combined with the temperature measurements inside the tower provide valuable information about the appearance of cooling towers as a function of fan operating status and time of day.

  14. Side Stream Filtration for Cooling Towers

    SciTech Connect

    2012-10-20

    This technology evaluation assesses side stream filtration options for cooling towers, with an objective to assess key attributes that optimize energy and water savings along with providing information on specific technology and implementation options. This information can be used to assist Federal sites to determine which options may be most appropriate for their applications. This evaluation provides an overview of the characterization of side stream filtration technology, describes typical applications, and details specific types of filtration technology.

  15. The Damaging Effects of Earthquake Excitation on Concrete Cooling Towers

    SciTech Connect

    Abedi-Nik, Farhad; Sabouri-Ghomi, Saeid

    2008-07-08

    Reinforced concrete cooling towers of hyperbolic shell configuration find widespread application in utilities engaged in the production of electric power. In design of critical civil infrastructure of this type, it is imperative to consider all the possible loading conditions that the cooling tower may experience, an important loading condition in many countries is that of the earthquake excitation, whose influence on the integrity and stability of cooling towers is profound. Previous researches have shown that the columns supporting a cooling tower are sensitive to earthquake forces, as they are heavily loaded elements that do not possess high ductility, and understanding the behavior of columns under earthquake excitation is vital in structural design because they provide the load path for the self weight of the tower shell. This paper presents the results of a finite element investigation of a representative 'dry' cooling tower, using realistic horizontal and vertical acceleration data obtained from the recent and widely-reported Tabas, Naghan and Bam earthquakes in Iran. The results of both linear and nonlinear analyses are reported in the paper, the locations of plastic hinges within the supporting columns are identified and the ramifications of the plastic hinges on the stability of the cooling tower are assessed. It is concluded that for the (typical) cooling tower configuration analyzed, the columns that are instrumental in providing a load path are influenced greatly by earthquake loading, and for the earthquake data used in this study the representative cooling tower would be rendered unstable and would collapse under the earthquake forces considered.

  16. Ozone inhibits corrosion in cooling towers

    NASA Technical Reports Server (NTRS)

    French, K. R.; Howe, R. D.; Humphrey, M. F.

    1980-01-01

    Commercially available corona discharge ozone generator, fitted onto industrial cooling tower, significantly reduces formation of scales (calcium carbonate) and corrosion. System also controls growth of algae and other microorganisms. Modification lowers cost and improves life of cooling system.

  17. Vortex-augmented cooling tower - windmill combination

    DOEpatents

    McAllister, J.E. Jr.

    1982-09-02

    A cooling tower for cooling large quantities of effluent water from a production facility by utilizing natural wind forces includes the use of a series of helically directed air inlet passages extending outwardly from the base of the tower to introduce air from any direction in a swirling vortical pattern while the force of the draft created in the tower makes it possible to place conventional power generating windmills in the air passage to provide power as a by-product.

  18. Stripping of phenols in model cooling towers

    SciTech Connect

    Turner, C.D.; Moe, T.A.; Wentz, C.A.

    1987-01-01

    Cooling towers are used to remove waste heat from unit operations in chemical processing plants. Using cooling towers for wastewater treatment and disposal through internal recycling has become an important alternative because of stricter wastewater discharge standards, the expense of specialized wastewater treatment systems and the limited availability and cost of water in arid regions. Designs for synfuels plants must address the problem of wastewater disposal. Alternative systems under consideration usually include zero discharge designs that incorporate evaporative cooling towers in the system. The mechanisms for contaminant removal in cooling towers are biological oxidation, stripping and chemical precipitation. Chemical precipitation is generally considered undesirable because of losses in heat transfer efficiency. Predicting whether stripping or biological oxidation will be the primary removal mechanism for phenolic compounds from coal conversion wastewaters used as makeup in cooling towers does not appear to be possible based on the results of these tests. The tests do indicate that the biological oxidation of phenol is possible in forced draft cooling towers.

  19. Mycobacteria in Finnish cooling tower waters.

    PubMed

    Torvinen, Eila; Suomalainen, Sini; Paulin, Lars; Kusnetsov, Jaana

    2014-04-01

    Evaporative cooling towers are water systems used in, e.g., industry and telecommunication to remove excess heat by evaporation of water. Temperatures of cooling waters are usually optimal for mesophilic microbial growth and cooling towers may liberate massive amounts of bacterial aerosols. Outbreaks of legionellosis associated with cooling towers have been known since the 1980's, but occurrences of other potentially pathogenic bacteria in cooling waters are mostly unknown. We examined the occurrence of mycobacteria, which are common bacteria in different water systems and may cause pulmonary and other soft tissue infections, in cooling waters containing different numbers of legionellae. Mycobacteria were isolated from all twelve cooling systems and from 92% of the 24 samples studied. Their numbers in the positive samples varied from 10 to 7.3 × 10(4) cfu/L. The isolated species included M. chelonae/abscessus, M. fortuitum, M. mucogenicum, M. peregrinum, M. intracellulare, M. lentiflavum, M. avium/nebraskense/scrofulaceum and many non-pathogenic species. The numbers of mycobacteria correlated negatively with the numbers of legionellae and the concentration of copper. The results show that cooling towers are suitable environments for potentially pathogenic mycobacteria. Further transmission of mycobacteria from the towers to the environment needs examination. PMID:23937212

  20. Rebuild cooling tower after partial collapse

    SciTech Connect

    Michell, F.L.; Demjanenko, W.

    1995-07-01

    When this tower suddenly went down, it forced the associated powerplant out of service. To restore operation required a quick assessment of the damage and fast action to reconstruct the tower. The partial collapse and prompt rebuild of a cooling tower at Columbus Southern Co`s Conesville station Unit 4 is a story of what can go wrong and what can be done to set matters right -- in a hurry. The utility is one of seven operating companies in American Electric Power Co`s system. Unit 4 is jointly owned with Cincinnati Gas and Electric Co and Dayton Power and Light Co. The 780-MW coal-fired unit`s closed-loop cooling-water system is served by two double-flow, seven-cell, mechanical-draft cooling towers (4A and 4B). The design basis calls for operating all 14 cells to maintain full load in the summer months.

  1. Salt water cooling tower retrofit experience

    SciTech Connect

    Rittenhouse, R.C.

    1994-06-01

    This article describes the experience of engineers at Atlantic Electric Co. with a recent cooling tower fill retrofit at the company's B.L. England Station, Unit 3. Note that this tower is unique. It is the first natural draft salt water tower to be built in the United States. Unit 3's closed-loop saltwater cooling system features a double condenser and two 50% capacity horizontal circulating water pumps. A natural draft cooling tower rejects heat to the atmosphere through evaporation and sensible heat transfer. The tower is 180 ft in diameter at the base and 208 ft high, and features a counterflow design. It was designed to cool 63,500 gpm of circulating salt water through a range of 26 F with an approach of 19.2 degrees at an ambient wet bulb temperature of 76 F and 60% relative humidity. A drift rate of 0.002% of circulating water flow was specified to avoid excessive salt water carryover.

  2. FIELD INVESTIGATION OF COOLING TOWER AND COOLING POND PLUMES

    EPA Science Inventory

    Measurements were made relating to the behavior of water-vapor plumes from forced-draft cooling towers and from cooling ponds. There were three categories of measurements. (1) Ambient weather data including temperature, humidity, wind speed and wind direction. These measurements ...

  3. 50. NORTHERN VIEW OF NONEVAPORATIVE WASTE WATER TREATMENT COOLING TOWERS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    50. NORTHERN VIEW OF NON-EVAPORATIVE WASTE WATER TREATMENT COOLING TOWERS IN CENTER, AND EVAPORATIVE WASTE WATER COOLING TOWERS ON RIGHT. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  4. PERFORMANCE ANALYSIS OF MECHANICAL DRAFT COOLING TOWER

    SciTech Connect

    Lee, S; Alfred Garrett, A; James02 Bollinger, J; Larry Koffman, L

    2009-02-10

    Industrial processes use mechanical draft cooling towers (MDCT's) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has cross-flow and counter-current MDCT's consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to simulate the cooling tower performance for the counter-current cooling tower and to conduct a parametric study under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model and performed the benchmarking analysis against the integral measurement results to accomplish the objective. The model uses three-dimensional steady-state momentum, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of parametric calculations was performed to investigate the impact of wind speeds and ambient conditions on the thermal performance of the cooling tower when fans were operating and when they were turned off. The model was also benchmarked against the literature data and the SRS integral test results for key parameters such as air temperature and humidity at the tower exit and water temperature for given ambient conditions. Detailed results will be published here.

  5. Legionella in Puerto Rico cooling towers

    SciTech Connect

    Negron-Alviro, A.; Perez-Suarez, I.; Hazen, T.C.

    1988-12-31

    Water samples from air conditioning cooling towers receiving different treatment protocols on five large municipal buildings in San Juan, Puerto Rico were assayed for various species and serogroups of Legionella spp. using direct immunofluorescence. Several water quality parameters were also measured with each sample. Guinea pigs were inoculated with water samples to confirm pathogenicity and recover viable organisms. Legionella pneumophila (1-6), L. bozemanii, L. micdadei, L. dumoffii, and L. gormanii were observed in at least one of the cooling towers. L. pneumophila was the most abundant species, reaching 10{sup 5} cells/ml, within the range that is considered potentially pathogenic to humans. A significantly higher density of L. pneumophila was observed in the cooling tower water that was not being treated with biocides. Percent respiration (INT) and total cell activity (AODC), were inversely correlated with bacterial density. This study demonstrates that Legionella spp. are present in tropical air-conditioning cooling systems, and without continuous biocide treatment may reach densities that present a health risk.

  6. Aspects of cooling tower biocides and protozoa

    SciTech Connect

    Berk, S.G.; Ashburn, R.J.; Ting, R.S.

    1998-12-31

    Previous work has shown that certain cooling tower amoebae and ciliated protozoa are resistant to several cooling tower biocides, even at the manufacturer`s recommended dosages. For the present study, an Acunthumoeba species was isolated from a cooling tower in Australia. Suspensions of the trophozoites (feeding stages) were exposed to isothiazolones. Cysts were tested separately. The minimum lethal concentration (MLC) for trophozoites was between 31-62 ppm of the biocide product, which is slightly less than the MLC for an amoebae species from the United States; and cyst forms were twofold more resistant than those of the US species, with a MLC of 62,500 ppm. A ciliate and an amoeba species were also exposed to bromochlorodimethylhydantoin. The MLC for the ciliate species was 1 ppm of the biocide product, and the MLC was 30--40 ppm for the amoeba trophozoites. Since amoebae can expel vesicles containing live Legionella, experiments were conducted to determine whether exposure of Acunthamoebu polyphugu to biocides influenced release of such potentially infectious particles. Vesicle release was not inhibited by any of the three biocides: quaternary ammonium compounds (QACs), isothiazolones, and a thiocarbamate compound. These results suggest that amoebae from various sources are resistant to recommended levels of biocides, and the amoebae may continue to release potentially infectious vesicles in the presence of biocides.

  7. Water-conserving cooling tower treatment

    SciTech Connect

    Mathie, A.J.

    1996-12-31

    Water conservation in cooling towers and evaporative coolers can finally become a reality. Also, fouled closed hot and chilled water systems can be restored to near original efficiency using the same technology. The barrier limiting the traditional water treatment industry from serious involvement in water conservation is the lack of a really good chemical to control scale. Poor scale inhibitors are the reason for a heavy bleed. Minerals concentrated by evaporation is wasted to the sewer while low solids make-up water fills the tower. Water conservation is important because of the increasing usable water shortage, the cost to add infrastructure to deliver increasing amounts of water to accommodate growth and the limitations imposed on disposal to the sewer. Now, due to innovations in chemical treatment, users of cooling towers and evaporative coolers can conserve water. In this presentation the author assumes the audience has some knowledge of traditional water treatment. Except for a few general references to establish common understanding, the author confines his remarks to discussing an advanced technology developed by DIAS, Inc., and the economics of its use.

  8. Analysis of Radiant Cooling System Configurations Integrated with Cooling Tower for Different Indian Climatic Zones

    SciTech Connect

    Mathur, Jyotirmay; Bhandari, Mahabir S; Jain, Robin; Srivastava, Prateek

    2016-01-01

    Radiant cooling system has proven to be a low energy consumption system for building cooling needs. This study describes the use of cooling tower in radiant cooling system to improve the overall system efficiency. A comprehensive simulation feasibility study of the application of cooling tower in radiant cooling system was performed for the fifteen cities in different climatic zones of India. It was found that in summer, the wet bulb temperature (WBT) of the different climatic zones except warm-humid is suitable for the integration of cooling tower with radiant cooling system. In these climates, cooling tower can provide on average 24 C to 27 C water In order to achieve the energy saving potential, three different configurations of radiant cooling system have been compared in terms of energy consumption. The different configurations of the radiant cooling system integrated with cooling tower are: (1) provide chilled water to the floor, wall and ceiling mounted tubular installation. (2) provide chilled water to the wall and ceiling mounted tabular installation. In this arrangement a separate chiller has also been used to provide chilled water at 16 C to the floor mounted tubular installation. (3) provide chilled water to the wall mounted tabular installation and a separate chiller is used to provide chilled water at 16 C to the floor and ceiling mounted tabular installation. A dedicated outdoor air system is also coupled for dehumidification and ventilation in all three configurations. A conventional all-air system was simulated as a baseline to compare these configurations for assessing the energy saving potential.

  9. Counter-Flow Cooling Tower Test Cell

    NASA Astrophysics Data System (ADS)

    Dvořák, Lukáš; Nožička, Jiří

    2014-03-01

    The article contains a design of a functional experimental model of a cross-flow mechanical draft cooling tower and the results and outcomes of measurements. This device is primarily used for measuring performance characteristics of cooling fills, but with a simple rebuild, it can be used for measuring other thermodynamic processes that take part in so-called wet cooling. The main advantages of the particular test cell lie in the accuracy, size, and the possibility of changing the water distribution level. This feature is very useful for measurements of fills of different heights without the influence of the spray and rain zone. The functionality of this test cell has been verified experimentally during assembly, and data from the measurement of common film cooling fills have been compared against the results taken from another experimental line. For the purpose of evaluating the data gathered, computational scripts were created in the MATLAB numerical computing environment. The first script is for exact calculation of the thermal balance of the model, and the second is for determining Merkel's number via Chebyshev's method.

  10. 36. EASTERN VIEW OF BOTTOM CONE OF GAS COOLING TOWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. EASTERN VIEW OF BOTTOM CONE OF GAS COOLING TOWER No. 1 AND TWO GAS COOLING TOWER SERVICE WATER PUMPS IN THE GAS WASHER PUMP HOUSE. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  11. PBF Cooling Tower. View of stairway to fan deck. Vents ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower. View of stairway to fan deck. Vents are made of redwood. Camera facing southwest toward north side of Cooling Tower. Siding is corrugated asbestos concrete. Photographer: Kirsh. Date: June 6, 1969. INEEL negative no. 69-3463 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  12. A numerical simulation of heat transfer in evaporative cooling towers

    NASA Astrophysics Data System (ADS)

    Benton, D. J.

    1983-09-01

    A phenomenological analysis was developed for the processes which occur within an evaporative cooling tower. The analysis includes the basic principles of mass, momentum, and energy conservation and empirical elationships for component characteristics such as transfer and pressure drop coefficients. A computer model which simulates the processes occurring in evaporative cooling towers was developed. The results of this computer model are compared to field data to verify the analysis and the computer modeling. The computer model may be used to analyze the performance of existing towers or to predict the performance of alternative tower designs.

  13. Enumeration of Legionella pneumophila in cooling tower water systems.

    PubMed

    Türetgen, Irfan; Sungur, Esra Ilhan; Cotuk, Aysin

    2005-01-01

    Legionella pneumophila, the causative agent of Legionnaires' disease, is known to colonise and frequently grow in cooling tower waters. Disease is acquired by inhaling aerosol contaminated by legionellae. Determination of the count of Legionella pneumophila in cooling tower waters may, therefore, be useful for risk assessment. In our survey, 103 water samples from 50 cooling towers were examined over a five-year period to indicate the seasonal distribution and the ecology of L. pneumophila, as regards temperature and pH. L. pneumophila serogroup 1 was found in 44% of the isolated strains, which is primarily responsible for the majority of Legionnaires' disease. The large majority of examined towers had levels of L. pneumophila in the high-risk category. These cooling towers have been linked to many outbreaks of Legionnaires' disease. PMID:15727299

  14. Use of nanofiltration to reduce cooling tower water usage.

    SciTech Connect

    Sanchez, Andres L.; Everett, Randy L.; Jensen, Richard Pearson; Cappelle, Malynda A.; Altman, Susan Jeanne

    2010-09-01

    Nanofiltration (NF) can effectively treat cooling-tower water to reduce water consumption and maximize water usage efficiency of thermoelectric power plants. A pilot is being run to verify theoretical calculations. A side stream of water from a 900 gpm cooling tower is being treated by NF with the permeate returning to the cooling tower and the concentrate being discharged. The membrane efficiency is as high as over 50%. Salt rejection ranges from 77-97% with higher rejection for divalent ions. The pilot has demonstrated a reduction of makeup water of almost 20% and a reduction of discharge of over 50%.

  15. Use of nanofiltration to reduce cooling tower water consumption.

    SciTech Connect

    Altman, Susan Jeanne; Ciferno, Jared

    2010-10-01

    Nanofiltration (NF) can effectively treat cooling-tower water to reduce water consumption and maximize water usage efficiency of thermoelectric power plants. A pilot is being run to verify theoretical calculations. A side stream of water from a 900 gpm cooling tower is being treated by NF with the permeate returning to the cooling tower and the concentrate being discharged. The membrane efficiency is as high as over 50%. Salt rejection ranges from 77-97% with higher rejection for divalent ions. The pilot has demonstrated a reduction of makeup water of almost 20% and a reduction of discharge of over 50%.

  16. Alternative cooling tower water treatment methods

    SciTech Connect

    Wilsey, C.A.

    1996-11-01

    The factors that contribute to proper water balance include total alkalinity, calcium hardness, and pH. In order to keep the cooling tower from scaling or corroding, a manipulation of these components is often necessary. This has traditionally been achieved with the use of chemicals, including but not limited to the following: acid, soda ash, sodium bicarbonate, calcium bicarbonate, algicide, and bactericide. Extensive research has shown that a balanced water system can also be achieved by using the proper combination of copper with a known halogen. Microbiologists have determined that a small amount of copper, acting as a supplement to chlorine at 0.4 ppm, has the same efficiency as 2.0 ppm free chlorine. Therefore, by using the following combination of components and procedures, the desired results can still be achieved: production of copper compound ions as a supplement to the chemical regimen; analysis and manipulation of make-up water; the use of copper as a coagulant for reduction of scale; copper as a supplemental bacterial disinfectant; and copper as an algicide.

  17. In Hot Water: A Cooling Tower Case Study

    ERIC Educational Resources Information Center

    Cochran, Justin; Raju, P. K.; Sankar, Chetan

    2005-01-01

    Problem Statement: Vogtle Electric Generating Plant operated by Southern Nuclear Operating Company, a subsidiary of Southern Company, has found itself at a decision point. Vogtle depends on their natural draft cooling towers to remove heat from the power cycle. Depending on the efficiency of the towers, the cycle can realize more or less power…

  18. In Hot Water: A Cooling Tower Case Study. Instructor's Manual

    ERIC Educational Resources Information Center

    Cochran, Justin; Raju, P. K.; Sankar, Chetan

    2005-01-01

    Vogtle Electric Generating Plant operated by Southern Nuclear Operating Company, a subsidiary of Southern Company, has found itself at a decision point. Vogtle depends on their natural draft cooling towers to remove heat from the power cycle. Depending on the efficiency of the towers, the cycle can realize more or less power output. The efficiency…

  19. 5. STEAM PLANT COOLING TOWER LOCATED WEST OF STEAM PLANT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. STEAM PLANT COOLING TOWER LOCATED WEST OF STEAM PLANT BUILDING, FROM SOUTH. SHOWS CURRENT LEVEL OF DISREPAIR. December 4, 1990 - Crosscut Steam Plant, North side Salt River near Mill Avenue & Washington Street, Tempe, Maricopa County, AZ

  20. 2. Left side of Zinc Plant, from packless Cooling Tower ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Left side of Zinc Plant, from packless Cooling Tower to midpoint of Cell Room, with majority of Upper Plant in view. View is to the east. - Sullivan Electrolytic Zinc Plant, Government Gulch, Kellogg, Shoshone County, ID

  1. 10. STATIC TEST TOWER CLOSEUP OF COOLING PIPES OF FLAME ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. STATIC TEST TOWER CLOSE-UP OF COOLING PIPES OF FLAME DEFLECTOR PIT ON NORTH ELEVATION. - Marshall Space Flight Center, Saturn Propulsion & Structural Test Facility, East Test Area, Huntsville, Madison County, AL

  2. 72. Joe Moore, Photographer. September, 1996. BEVATRON COOLING TOWERS (3 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    72. Joe Moore, Photographer. September, 1996. BEVATRON COOLING TOWERS (3 SHOWN) AND MOTOR GENERATOR ON RIGHT - University of California Radiation Laboratory, Bevatron, 1 Cyclotron Road, Berkeley, Alameda County, CA

  3. AIRBORNE MONITORING OF COOLING TOWER EFFLUENTS. VOLUME I. TECHNICAL SUMMARY

    EPA Science Inventory

    MRI conducted an airborne plume monitoring program as part of the Chalk Point Cooling Tower Project. Plume measurement included: temperature, dew point, visibility, turbulence, droplet size distribution and concentration, liquid water content, sodium chloride concentration (NaCl)...

  4. 16. SOUTH SIDE OF STEAM PLANT COOLING TOWER IN OPERABLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. SOUTH SIDE OF STEAM PLANT COOLING TOWER IN OPERABLE CONDITION, WITH STACKS OF ORIGINAL BOILERS IN BACKGROUND. June 10, 1941 - Crosscut Steam Plant, North side Salt River near Mill Avenue & Washington Street, Tempe, Maricopa County, AZ

  5. EXPERIMENTAL SIMULATION OF SINGLE AND MULTIPLE CELL COOLING TOWER PLUMES

    EPA Science Inventory

    An experimental investigation was conducted to determine the dilution characteristics of single and multiple port buoyant discharges typical of modern natural and mechanical draft cooling towers. Simultaneous measurements of velocity and tracer concentration profiles were taken a...

  6. Use of cooling tower blow down in ethanol fermentation.

    PubMed

    Rajagopalan, N; Singh, V; Panno, B; Wilcoxon, M

    2010-01-01

    Reducing water consumption in bioethanol production conserves an increasingly scarce natural resource, lowers production costs, and minimizes effluent management issues. The suitability of cooling tower blow down water for reuse in fermentation was investigated as a means to lower water consumption. Extensive chemical characterization of the blow down water revealed low concentrations of toxic elements and total dissolved solids. Fermentation carried out with cooling tower blow down water resulted in similar levels of ethanol and residual glucose as a control study using deionized water. The study noted good tolerance by yeast to the specific scale and corrosion inhibitors found in the cooling tower blow down water. This research indicates that, under appropriate conditions, reuse of blow down water from cooling towers in fermentation is feasible. PMID:21076211

  7. Evaluation of IR technology applied to cooling tower performance

    NASA Astrophysics Data System (ADS)

    MacNamara, Neal A.; Zayicek, Paul A.

    1999-03-01

    Infrared thermography (IR) is widely used by electric utilities as an integral part of their predictive maintenance program. IR is utilized for inspection of a variety of plant mechanical and electrical components. Additionally, IR can be used to provide thermal performance information for other key plant systems, including assessment of cooling towers. Cooling tower performance directly affects availability and heat rate in fossil and nuclear power plants. Optimal tower performance contributes to efficient turbine operation and maximum power output. It is estimated that up to half of the cooling towers installed have failed to meet their design performance specifications. As a result, any additional degradation of tower performance resulting from fouling, valve degradation, unbalanced flow, or a poor maintenance practice has a direct effect on generation output. We have collected infrared thermography images of mechanical draft cooling towers, as part of Evaluation of IR Technology Applied to Cooling Tower Performance. IR images have been analyzed to provide information regarding general performance conditions and identification of operational deficiencies related to thermal performance. Similarly, IR can be implemented for monitoring of tower flow balance activities and for post-maintenance surveillance. To date, IR images have been used to identify areas of general flow imbalance, flooding or limited flow in individual cells, missing or broken tower fill material, fan performance and other problems related to maintenance or operational issues. Additionally, an attempt is being made to use quantitative thermal data, provided by the IR image analysis software, in conjunction with condenser input/output site ambient information, to evaluate and compare individual tower cell performance.

  8. Environmental Impacts from the Operation of Cooling Towers at SRP

    SciTech Connect

    Smith, F.G. III

    2001-06-26

    An assessment has been made of the environmental effects that would occur from the operation of cooling towers at the SRP reactors. A more realistic numerical model of the cooling tower plume has been used to reassess the environmental impacts. The following effects were considered: (1) the occurrence of fog and ice and their impact on nearby structures, (2) drift and salt deposition from the plume, (3) the length and height of the visible plume, and (4) the possible dose from tritium.

  9. Wastewater reuse as cooling-tower makeup: Final report

    SciTech Connect

    Goldstein, D.; Wei, I.; Casana, J.

    1987-08-01

    The objectives of this program are to document electric utility experience and concerns on the use of municipal wastewater as makeup to cooling towers and to identify areas lacking sufficient information for their application as well as to identify problem areas. Current users of municipal wastewater in electric utility cooling towers have been contacted and the literature has been reviewed. In addition, literature on the reuse of industrial wastewater has been reviewed. The findings are summarized in this report with emphasis on the use of municipal wastewater in electric utility cooling towers. It was found that this practice has been going on for sufficient time at sufficient places that the problems are fairly well understood. Scale formation by calcium phosphate is a problem. It is controlled by pH reduction or by removal of phosphate and suggested techniques are given. Fouling by slime is a problem. It is controlled by heavy doses of chlorine and other biocides or by mechanical and other non-chemical means without use of any biocide. Foaming, corrosion and blowdown disposal are not problems. There are a number of problem areas where more information is desired to establish a higher level of confidence in using sewage water as makeup. Three areas of research are recommended: (1) a study comparing the technological and environmental problems and costs of various technologies used to control the formation of biological slime, (2) laboratory and pilot scale testing to verify the prediction techniques for phosphate precipitation, and (3) to determine whether the health hazards of using sewage water are worse than the use of normal waters.

  10. Main photoautotrophic components of biofilms in natural draft cooling towers.

    PubMed

    Hauer, Tomáš; Čapek, Petr; Böhmová, Petra

    2016-05-01

    While photoautotrophic organisms are an important component of biofilms that live in certain regions of natural draft cooling towers, little is known about these communities. We therefore examined 18 towers at nine sites to identify the general patterns of community assembly in three distinct tower parts, and we examined how community structures differ depending on geography. We also compared the newly acquired data with previously published data. The bottom sections of draft cooling towers are mainly settled by large filamentous algae, primarily Cladophora glomerata. The central portions of towers host a small amount of planktic algae biomass originating in the cooling water. The upper fourths of towers are colonized by biofilms primarily dominated by cyanobacteria, e.g., members of the genera Gloeocapsa and Scytonema. A total of 41 taxa of phototrophic microorganisms were identified. Species composition of the upper fourth of all towers was significantly affected by cardinal position. There was different species composition at positions facing north compared to positions facing south. West- and east-facing positions were transitory and highly similar to each other in terms of species composition. Biofilms contribute to the degradation of paint coatings inside towers. PMID:26508444

  11. PBF Cooling Tower detail. Camera facing southwest into north side ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower detail. Camera facing southwest into north side of Tower. Five horizontal layers of splash bars constitute fill decks, which will break up falling water into droplets, promoting evaporative cooling. Louvered faces, through which air enters tower, are on east and west sides. Louvers have been installed. Support framework for one of two venturi-shaped fan stacks (or "vents") is in center top. Orifices in hot basins (not in view) will distribute water over fill. Photographer: Kirsh. Date: May 15, 1969. INEEL negative no. 69-3032 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  12. Coagulation chemistries for silica removal from cooling tower water.

    SciTech Connect

    Nyman, May Devan; Altman, Susan Jeanne; Stewart, Tom

    2010-02-01

    The formation of silica scale is a problem for thermoelectric power generating facilities, and this study investigated the potential for removal of silica by means of chemical coagulation from source water before it is subjected to mineral concentration in cooling towers. In Phase I, a screening of many typical as well as novel coagulants was carried out using concentrated cooling tower water, with and without flocculation aids, at concentrations typical for water purification with limited results. In Phase II, it was decided that treatment of source or make up water was more appropriate, and that higher dosing with coagulants delivered promising results. In fact, the less exotic coagulants proved to be more efficacious for reasons not yet fully determined. Some analysis was made of the molecular nature of the precipitated floc, which may aid in process improvements. In Phase III, more detailed study of process conditions for aluminum chloride coagulation was undertaken. Lime-soda water softening and the precipitation of magnesium hydroxide were shown to be too limited in terms of effectiveness, speed, and energy consumption to be considered further for the present application. In Phase IV, sodium aluminate emerged as an effective coagulant for silica, and the most attractive of those tested to date because of its availability, ease of use, and low requirement for additional chemicals. Some process optimization was performed for coagulant concentration and operational pH. It is concluded that silica coagulation with simple aluminum-based agents is effective, simple, and compatible with other industrial processes.

  13. ETR COOLING TOWER. PUMP HOUSE (TRA645) IN SHADOW OF TOWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ETR COOLING TOWER. PUMP HOUSE (TRA-645) IN SHADOW OF TOWER ON LEFT. AT LEFT OF VIEW, HIGH-BAY BUILDING IS ETR. ONE STORY ATTACHMENT IS ETR ELECTRICAL BUILDING. STACK AT RIGHT IS ETR STACK; MTR STACK IS TOWARD LEFT. CAMERA FACING NORTHEAST. INL NEGATIVE NO. 56-3799. Jack L. Anderson, 11/26/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  14. COOLING TOWER PUMP HOUSE, TRA606. THREE OF SIX SECTIONS OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    COOLING TOWER PUMP HOUSE, TRA-606. THREE OF SIX SECTIONS OF COOLING TOWER ARE VISIBLE ABOVE RAILING. PUMP HOUSE IN FOREGROUND IS ON SOUTH SIDE OF COOLING TOWER. NOTE THREE PIPES TAKING WATER FROM PUMP HOUSE TO HOT DECK OF COOLING TOWER. EMERGENCY WATER SUPPLY TOWER IS ALSO IN VIEW. INL NEGATIVE NO. 6197. Unknown Photographer, 6/27/1952 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  15. Pontiac fever outbreak associated with a cooling tower.

    PubMed Central

    Friedman, S; Spitalny, K; Barbaree, J; Faur, Y; McKinney, R

    1987-01-01

    In late April 1984, an outbreak of Pontiac fever was investigated in an office building in lower Manhattan (New York City). The outbreak was characterized by a high attack rate (78 per cent overall); the predominant symptoms were myalgias, chills, fatigue, fever, and headache. There was a clustering of cases in an office that was air cooled by a dedicated cooling tower separate from the remainder of the building. A high concentration of live L. Pneumophila cells in the cooling tower was quantified. Airborne spread via settle plates placed along the air intake system and within the office was demonstrated. Legionella pneumophila serogroup 1 antigen was found in the urine of two cases, and identical monoclonal antibody reactivity patterns of isolates from all sources was observed. Difficulty was experienced in eliminating the organism from the tower. PMID:3565648

  16. Effectiveness of bromicide against Legionella pneumophila in a cooling tower

    SciTech Connect

    Fliermans, C.B.; Harvey, R.S.

    1983-01-01

    Cooling towers are considered to be man-made amplifiers of Legionella. Thus the proper maintenance and choice of biocides is important. The only biocide that has thus far been shown to be effective in field tests is the judicious use of chlorination. Perturbation studies were conducted on an industrial cooling tower shown to contain Legionella, using 1-bromo-3-chloro-5,5-dimethylhydantoin (Bromicide, Great Lakes Chemical Corp.). At the manufacturer's recommended concentrations neither the density nor the activity of Legionella was affected. At concentrations greater than 2.0 ppM free residual, the Bromicide was not effective in reducing Legionella to source water concentrations, nor was it effective in reducing the INT activity of the bacterium in situ. The data indicate that at concentrations up to 2.0 ppM, Bromicide is not effective in these tower studies. 23 references, 3 tables.

  17. PBF Cooling Tower under construction. Cold water basin is five ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower under construction. Cold water basin is five feet deep. Foundation and basin walls are reinforced concrete. Camera facing west. Pipe openings through wall in front are outlets for return flow of cool water to reactor building. Photographer: John Capek. Date: September 4, 1968. INEEL negative no. 68-3473 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  18. PBF Cooling Tower detail. Camera facing southwest. Wood fill rises ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower detail. Camera facing southwest. Wood fill rises from foundation piers of cold water basin. Photographer: Kirsh. Date: May 1, 1969. INEEL negative no. 69-2826 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  19. 77. VIEW OF COOLING TOWER NEAR NORTH FACE OR LSB ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    77. VIEW OF COOLING TOWER NEAR NORTH FACE OR LSB (BLDG. 779). MST ELECTRICAL CONNECTION PANEL ON LAUNCH DECK IN CENTER BACKGROUND. MST IN PARKED POSITION VISIBLE IN UPPER RIGHT CORNER OF PHOTO. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  20. 49. LOOKING NORTH AT EVAPORATIVE WASTE WATER TREATMENT COOLING TOWERS, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. LOOKING NORTH AT EVAPORATIVE WASTE WATER TREATMENT COOLING TOWERS, WITH BLOW ENGINE HOUSE No. 3 ON RIGHT, AND FILTER CAKE HOUSE IN FOREGROUND. (Jet Lowe) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  1. Indiana State University Graduates to Advanced Plastic Cooling Towers

    ERIC Educational Resources Information Center

    Sullivan, Ed

    2012-01-01

    Perhaps more than many other industries, today's universities and colleges are beset by dramatically rising costs on every front. One of the areas where overhead can be contained or reduced is in the operation of the chilled water systems that support air conditioning throughout college campuses, specifically the cooling towers. Like many…

  2. Cooling tower windage: a new aspect to environmental assessment

    SciTech Connect

    Taylor, F. G.; Park, S. H.

    1980-01-01

    Results of the several investigations provided quantitative estimates of windage from Oak Ridge Gaseous Diffusion Plant cooling towers. Windage water deposited on the ground has the potential to reach nearby streams through runoff. Windage deposited on moisture depleted soils would not be significant. During winter months at Oak Ridge soils generally have a high moisture content such that windage deposition could be quickly transported as runoff. It is during this time that cooling towers are sometimes operated without fan-induced draft. Since windage water contains the same hexavalent chromium concentration (9 ppM) as the recirculating cooling water system, the runoff stream from the K-892J tower constitues a NPDES violation as an unpermitted discharge. As a long-term abatement strategy, concrete aprons were constructed along each side of new cooling towers at the Paducah, Kentucky Gaseous Diffusion Plant. The maximum distance of windage impact is wind dependent. If apron construction is envisioned as an abatement strategy at Oak Ridge, the maximum distance of impact can be inferred graphically from the several points where windage (fans off) and drift (fans on) loss curves intersect under the different meteorological conditions. Once the hexavalent chromium laden runoff stream reaches Poplar Creek, it is diluted well below the standards for drinking water and poses little potential for biological effects to aquatic systems.

  3. Plan now for cold-weather operation of cooling towers

    SciTech Connect

    Michell, F.L.; Drew, D.H.

    1996-06-01

    This article describes what a midwestern utility has done to keep natural-draft towers running when faced with long bouts of high winds and single-digit temperatures. Severe ice buildup is the biggest threat. American Electric Power Co. (AEP) has six crossflow and eight counterflow natural-draft hyperbolic cooling towers in operation today. In the crossflow designs, subject of this discussion, the fill sections are more exposed to wind and cold. Their design circulating-water flow rates range from 220,000 to 600,000 gal/min; they serve 600-, 800-, and 1,300-MW coal-fired generating units. The towers are located in the Midwest and experience long periods of sub-freezing conditions during the winter months. High winds accompanied by single-digit temperatures often prevail for days at a time. During the record cold spell in January 1994, average temperatures as low as {minus}20 F occurred throughout AEP`s service area. Fill bypass systems have been incorporated into the design of AEP`s natural-draft cooling towers, and can pass between 25 and 50% of full-rated circulating-water flow. These systems prevent ice formation within the fill sections (heat-transfer media) by recirculating water directly to the tower cold-water basin during winter startup, when heat content of the circulating water is relatively low.

  4. Water distribution characteristics of spray nozzles in a cooling tower

    NASA Astrophysics Data System (ADS)

    Vitkovic, Pavol

    2015-05-01

    Water distribution characteristics of spray nozzles with spray plates used to distribute cooling water to the cooling fills in a cooling tower is one of the important parameters for the selection of nozzles. Water distribution characteristic describes the distribution of water from the axis of the nozzle along a fill. One of the parameters affecting the water distribution characteristic of the nozzle is airflow velocity of counter flow airstream. Water distribution characteristics are commonly measured using by a set of containers. The problem with this method of the measurement of characteristics is block of the airflow with collections of containers. Therefore, this work is using the visualization method.

  5. Factors stimulating propagation of legionellae in cooling tower water

    SciTech Connect

    Yamamoto, Hiroyuki; Sugiura, Minoru; Kusunoki, Shinji; Ezaki, Takayuki; Ikedo, Masanari; Yabuuchi, Eiko )

    1992-04-01

    The authors survey of cooling tower water demonstrated that the highest density of legionellae, {ge}10{sup 4} CFU/100 ml, appeared in water containing protozoa, {ge}10{sup 2} MPN/100 ml, and heterotrophic bacteria, {ge}10{sup 6} CFU/100 ml, at water temperatures between 25 and 35C. Viable counts of legionellae were detected even in the winter samples, and propagation, up to 10{sup 5} CFU/100 ml, occurs in summer. The counts of legionellae correlated positively with increases in water temperature, pH, and protozoan counts, but not with heterotrophic bacterial counts. The water temperature of cooling towers may promote increases in the viable counts of legionellae, and certain microbes, e.g., protozoa or some heterotrophic bacteria, may be a factor stimulating the propagation of legionellae.

  6. Investigation of Natural Draft Cooling Tower Performance Using Neural Network

    NASA Astrophysics Data System (ADS)

    Mahdi, Qasim S.; Saleh, Saad M.; Khalaf, Basima S.

    In the present work Artificial Neural Network (ANN) technique is used to investigate the performance of Natural Draft Wet Cooling Tower (NDWCT). Many factors are affected the rang, approach, pressure drop, and effectiveness of the cooling tower which are; fill type, water flow rate, air flow rate, inlet water temperature, wet bulb temperature of air, and nozzle hole diameter. Experimental data included the effects of these factors are used to train the network using Back Propagation (BP) algorithm. The network included seven input variables (Twi, hfill, mw, Taiwb, Taidb, vlow, vup) and five output variables (ma, Taowb, Two, Δp, ɛ) while hidden layer is different for each case. Network results compared with experimental results and good agreement was observed between the experimental and theoretical results.

  7. CFD MODELING ANALYSIS OF MECHANICAL DRAFT COOLING TOWER

    SciTech Connect

    Lee, S; Alfred Garrett, A; James02 Bollinger, J; Larry Koffman, L

    2008-03-03

    Industrial processes use mechanical draft cooling towers (MDCT's) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has a MDCT consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to conduct a parametric study for cooling tower performance under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model to achieve the objective. The model uses three-dimensional steady-state momentum, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of the modeling calculations was performed to investigate the impact of ambient and operating conditions on the thermal performance of the cooling tower when fans were operating and when they were turned off. The model was benchmarked against the literature data and the SRS test results for key parameters such as air temperature and humidity at the tower exit and water temperature for given ambient conditions. Detailed results will be presented here.

  8. PBF Cooling Tower. View from highbay roof of Reactor Building ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower. View from high-bay roof of Reactor Building (PER-620). Camera faces northwest. East louvered face has been installed. Inlet pipes protrude from fan deck. Two redwood vents under construction at top. Note piping, control, and power lines at sub-grade level in trench leading to Reactor Building. Photographer: Kirsh. Date: June 6, 1969. INEEL negative no. 69-3466 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  9. Role of bacterial adhesion in the microbial ecology of biofilms in cooling tower systems.

    PubMed

    Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron

    2009-01-01

    The fate of the three heterotrophic biofilm forming bacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. in pilot scale cooling towers was evaluated both by observing the persistence of each species in the recirculating water and the formation of biofilms on steel coupons placed in each cooling tower water reservoir. Two different cooling tower experiments were performed: a short-term study (6 days) to observe the initial bacterial colonization of the cooling tower, and a long-term study (3 months) to observe the ecological dynamics with repeated introduction of the test strains. An additional set of batch experiments (6 days) was carried out to evaluate the adhesion of each strain to steel surfaces under similar conditions to those found in the cooling tower experiments. Substantial differences were observed in the microbial communities that developed in the batch systems and cooling towers. P. aeruginosa showed a low degree of adherence to steel surfaces both in batch and in the cooling towers, but grew much faster than K. pneumoniae and Flavobacterium in mixed-species biofilms and ultimately became the dominant organism in the closed batch systems. However, the low degree of adherence caused P. aeruginosa to be rapidly washed out of the open cooling tower systems, and Flavobacterium became the dominant microorganism in the cooling towers in both the short-term and long-term experiments. These results indicate that adhesion, retention and growth on solid surfaces play important roles in the bacterial community that develops in cooling tower systems. PMID:19177226

  10. Role of bacterial adhesion in the microbial ecology of biofilms in cooling tower systems

    PubMed Central

    Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P.; Packman, Aaron

    2009-01-01

    The fate of the three heterotrophic biofilm forming bacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. in pilot scale cooling towers was evaluated both by observing the persistence of each species in the recirculating water and the formation of biofilms on steel coupons placed in each cooling tower water reservoir. Two different cooling tower experiments were performed: a short-term study (6 days) to observe the initial bacterial colonization of the cooling tower, and a long-term study (3 months) to observe the ecological dynamics with repeated introduction of the test strains. An additional set of batch experiments (6 days) was carried out to evaluate the adhesion of each strain to steel surfaces under similar conditions to those found in the cooling tower experiments. Substantial differences were observed in the microbial communities that developed in the batch systems and cooling towers. P. aeruginosa showed a low degree of adherence to steel surfaces both in batch and in the cooling towers, but grew much faster than K. pneumoniae and Flavobacterium in mixed-species biofilms and ultimately became the dominant organism in the closed batch systems. However, the low degree of adherence caused P. aeruginosa to be rapidly washed out of the open cooling tower systems, and Flavobacterium became the dominant microorganism in the cooling towers in both the short-term and long-term experiments. These results indicate that adhesion, retention and growth on solid surfaces play important roles in the bacterial community that develops in cooling tower systems. PMID:19177226

  11. NONWATER QUALITY IMPACTS OF CLOSED-CYCLE COOLING SYSTEMS AND THE INTERACTION OF STACK GAS AND COOLING TOWER PLUMES

    EPA Science Inventory

    The report gives results of a literature survey of the nonwater quality impacts of closed-cycle cooling systems. Following discussions of cooling tower and stack gas plumes, interactions of these plumes are considered. For cooling tower plumes, plume types, behavior, salt drift g...

  12. Cooling tower irrigator layout with allowances for non-uniformity of the airflow velocity field

    NASA Astrophysics Data System (ADS)

    Pushnov, A. S.; Ryabushenko, A. S.

    2016-07-01

    This article covers the results of analysis of aerodynamic processes in the cooling tower irrigator and provides the approaches to optimal layout of preformed packing blocks (of the irrigator) developed based on these results. The analysis of the airflow velocity field in the cooling towers shows that the irrigation space can be broken down into the following zones: the peripheral zone of the cooling tower near the airblast windows, the zone near the cooling tower center, and the intermediate zone. Furthermore, the highest level of nonuniformity of the airflow velocity field in cooling towers is in the zone adjoining the tower's airblast windows. The proposed concept of the cooling tower irrigator's layout is made with allowances for the airflow velocity field characteristics in the cross-section of the irrigation space of the cooling tower. Based on this concept, we suggest that higher irrigator blocks should be placed in the zone of increased airflow consumption, which provides the possibility to enhance the hydraulic resistance and, respectively, decrease the gas flow velocity as well as to boost the efficiency of chilling the circulating water in the cooling tower. For this purpose, additional irrigator blocks can be of the same design as the main irrigator. As an option, it is possible to use blocks of the geometry and design other than the main irrigator block in the cooling tower.

  13. Maintenance of cooling towers following two outbreaks of Legionnaires' disease in a city.

    PubMed Central

    Bhopal, R. S.; Barr, G.

    1990-01-01

    This survey assessed the maintenance of evaporative cooling towers in Glasgow, following two Legionnaires' disease outbreaks. Information was obtained from 76 of 81 premises and a maintenance score was calculated for each of 174 towers. The quality of maintenance was extremely varied (range of maintenance scores, 8-30; mean, 22 (S.D., 5.0); median, 23; maximum possible, 33) and some towers were neglected. Breaches of maintenance principles were mainly structural and organizational, e.g. inadequate drift control, rather than failure to use chemicals. Low maintenance scores were associated with no log book, no guidelines, no change in procedures in last 5 years, solitary cooling towers, and towers on industrial premises. Despite intense publicity the standard of cooling tower maintenance in Glasgow remained a concern. Information campaigns directed at those responsible for cooling-tower maintenance are necessary. PMID:2307183

  14. The efficiency index of mechanical-draft and chimney-type water cooling towers operation

    NASA Astrophysics Data System (ADS)

    Sosnovskii, S. K.; Kravchenko, V. P.

    2014-09-01

    It is shown that the water temperature ranges in cooling towers given in the regulatory documents are not consistent with the standardized heat loads. It is also demonstrated that the existing criteria for estimating the effect from retrofitting of cooling towers are far from being perfect. The notions of cooling tower efficiency index and their operating characteristics with the nominal values of the main parameters are introduced. A procedure for determining these quantities is developed. An algorithm for directly calculating the economic effect from reconstruction of cooling towers is proposed.

  15. Gasifier waste water treatment: Phase I cooling tower assessment

    SciTech Connect

    Mann, M.D.; Willson, W.G.; Hendrikson, J.G.; Winton, S.L.

    1985-02-01

    Details of an advanced study of the treatability of waste waters from the fixed-bed gasification of lignite describe the test equipment and results at a pilot plant in North Dakota using stripped-gas liquor (SGL) as cooling tower makeup. Ammonia, alkalinity, phenol, and other non-hydantoin organics were removed from the cooling water by stripping and/or biological degradation, with the phenol concentration in the exhaust air exceeding the odor threshold. It will be necessary to control foaming of the circulating water, but both glycol and silicon based agents performed well during the test. It will also be necessary to reduce the high level of biofouling on heat transfer surfaces, although stainless steel fouling was not a major problem. The conclusion is that SGL is limited by potentially serious operating problems without additional treatment. 5 references, 4 figures, 7 tables.

  16. PBF Cooling Tower and it Auxiliary Building (PER624) to left ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower and it Auxiliary Building (PER-624) to left of tower. Camera facing west and the east louvered face of the tower. Details include secondary coolant water riser piping and flow control valves (butterfly valves) to distribute water evenly to all sections of tower. Photographer: Holmes. Date: May, 20, 1970. INEEL negative no. 70-2322 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  17. Flue gas injection control of silica in cooling towers.

    SciTech Connect

    Brady, Patrick Vane; Anderson, Howard L., Jr.; Altman, Susan Jeanne

    2011-06-01

    Injection of CO{sub 2}-laden flue gas can decrease the potential for silica and calcite scale formation in cooling tower blowdown by lowering solution pH to decrease equilibrium calcite solubility and kinetic rates of silica polymerization. Flue gas injection might best inhibit scale formation in power plant cooling towers that use impaired makeup waters - for example, groundwaters that contain relatively high levels of calcium, alkalinity, and silica. Groundwaters brought to the surface for cooling will degas CO{sub 2} and increase their pH by 1-2 units, possibly precipitating calcite in the process. Recarbonation with flue gas can lower the pHs of these fluids back to roughly their initial pH. Flue gas carbonation probably cannot lower pHs to much below pH 6 because the pHs of impaired waters, once outgassed at the surface, are likely to be relatively alkaline. Silica polymerization to form scale occurs most rapidly at pH {approx} 8.3 at 25 C; polymerization is slower at higher and lower pH. pH 7 fluids containing {approx}220 ppm SiO{sub 2} require > 180 hours equilibration to begin forming scale whereas at pH 8.3 scale formation is complete within 36 hours. Flue gas injection that lowers pHs to {approx} 7 should allow substantially higher concentration factors. Periodic cycling to lower recoveries - hence lower silica concentrations - might be required though. Higher concentration factors enabled by flue gas injection should decrease concentrate volumes and disposal costs by roughly half.

  18. Development of a new seminested PCR method for detection of Legionella species and its application to surveillance of legionellae in hospital cooling tower water.

    PubMed Central

    Miyamoto, H; Yamamoto, H; Arima, K; Fujii, J; Maruta, K; Izu, K; Shiomori, T; Yoshida, S

    1997-01-01

    The presence of PCR inhibitors in water samples is well known and contributes to the fact that a practical PCR assay has not been developed for legionella surveillance. In this study, we devised a new seminested PCR assay for detection of Legionella spp. in water samples as a means of overriding the PCR inhibitors without loss of sensitivity. The seminested PCR assay utilized primers to amplify the 16S rRNA gene (LEG primers) of 39 Legionella spp. The assay was specific to legionellae, and the sensitivity was 1 fg of extracted Legionella DNA in laboratory examination. To evaluate the feasibility and sensitivity of the PCR assay in identifying the presence of legionellae, it was used to survey Legionella contamination in the water of 49 cooling towers of 32 hospitals. A commercially available EnviroAmp Legionella kit and a culture method were also used in the survey for comparison with the seminested PCR assay. The detection rates of legionellae in the samples were 91.8% (45 of 49) by the PCR assay and 79.5% (39 of 49) by the culture method. The EnviroAmp kit revealed that 30.6% of the water samples (15 of 49) contained inhibitors of the PCR amplification. However, the seminested PCR assay could produce the Legionella-specific DNA bands in 14 of the 15 samples. Although 8 of the 14 samples were positive in the first-step PCR, 6 of the 14 samples became positive in the second-step PCR. These results suggest that the effect of PCR inhibitors in samples, if any, can be reduced because of the dilution of the sample in the second-step PCR and that sensitivity of detection can be increased by the second-step PCR. Thus, the seminested PCR assay with LEG primers to amplify the 16S rRNA gene of 39 Legionella spp. was a practical and sensitive method to detect Legionella spp. in water samples. PMID:9212400

  19. PBF Cooling Tower Auxiliary Building (PER624) interior. Camera facing north. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower Auxiliary Building (PER-624) interior. Camera facing north. Deluge valves and automatic fire protection piping for Cooling Tower. Photographer: Holmes. Date: May 20, 1970. INEEL negative no. 70-2323 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  20. PBF. Oblique and contextual view of PBF Cooling Tower, PER720. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF. Oblique and contextual view of PBF Cooling Tower, PER-720. Camera facing northeast. Auxiliary Building (PER-624) abuts Cooling Tower. Demolition equipment has arrived. Date: August 2003. INEEL negative no. HD-35-11-2 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  1. PBF Cooling Tower (PER720). Camera faces east to show west ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower (PER-720). Camera faces east to show west facade. Sloped (louvered) panels in this and opposite facade allow air to enter tower and cool water falling on splash bars within. Date: August 2003. INEEL negative no. HD-35-10-2 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  2. Method and system for simulating heat and mass transfer in cooling towers

    DOEpatents

    Bharathan, Desikan; Hassani, A. Vahab

    1997-01-01

    The present invention is a system and method for simulating the performance of a cooling tower. More precisely, the simulator of the present invention predicts values related to the heat and mass transfer from a liquid (e.g., water) to a gas (e.g., air) when provided with input data related to a cooling tower design. In particular, the simulator accepts input data regarding: (a) cooling tower site environmental characteristics; (b) cooling tower operational characteristics; and (c) geometric characteristics of the packing used to increase the surface area within the cooling tower upon which the heat and mass transfer interactions occur. In providing such performance predictions, the simulator performs computations related to the physics of heat and mass transfer within the packing. Thus, instead of relying solely on trial and error wherein various packing geometries are tested during construction of the cooling tower, the packing geometries for a proposed cooling tower can be simulated for use in selecting a desired packing geometry for the cooling tower.

  3. PERFORMANCE EVALUATION OF THE BRAINTREE ELECTRIC LIGHT DEPARTMENT DRY COOLING TOWER

    EPA Science Inventory

    The report gives results of a 5-year evaluation of the performance of a dry cooling tower for the 20-MW steam-electric generation portion of an 85-MW combined-cycle power plant. Objectives of the study were to: demonstrate dry cooling tower technology at a Massachusetts seacoast ...

  4. Analyzing the possibility of achieving more efficient cooling of water in the evaporative cooling towers of the Armenian NPP

    NASA Astrophysics Data System (ADS)

    Petrosyan, V. G.; Yeghoyan, E. A.

    2015-10-01

    The specific features of the service cooling water system used at the Armenian NPP and modifications made in the arrangement for supplying water to the water coolers in order to achieve more efficient cooling are presented. The mathematical model applied in carrying out the analyses is described, the use of which makes it possible to investigate the operation of parallel-connected cooling towers having different hydraulic and thermal loads. When the third standby cooling tower is put into operation (with the same flow rate of water supplied to the water coolers), the cooled water temperature is decreased by around 2-3°C in the range of atmospheric air temperatures 0-35°C. However, the introduced water distribution arrangement with a decreased spraying density has limitation on its use at negative outdoor air temperatures due to the hazard intense freezing of the fill in the cooling tower peripheral zone. The availability of standby cooling towers in the shutdown Armenian NPP power unit along with the planned full replacement of the cooling tower process equipment create good possibilities for achieving a deeper water cooling extent and better efficiency of the NPP. The present work was carried out with the aim of achieving maximally efficient use of existing possibilities and for elaborating the optimal cooling tower modernization version. Individual specific heat-andmass transfer processes in the chimney-type evaporative cooling towers are analyzed. An improved arrangement for distributing cooled water over the cooling tower spraying area (during its operation with a decreased flow rate) is proposed with the aim of cooling water to a deeper extent and preserving the possibility of using the cooling towers in winter. The main idea behind improving the existing arrangement is to exclude certain zones of the cooling tower featuring inefficient cooling from operation. The effectiveness of introducing the proposed design is proven by calculations (taking as an

  5. Legionella oakridgensis: unusual new species isolated from cooling tower water.

    PubMed Central

    Orrison, L H; Cherry, W B; Tyndall, R L; Fliermans, C B; Gough, S B; Lambert, M A; McDougal, L K; Bibb, W F; Brenner, D J

    1983-01-01

    We describe a new species of Legionella represented by 10 strains isolated from industrial cooling towers. Legionella oakridgensis differed genetically from the other seven species of Legionella in DNA hybridization studies and differed serologically in direct fluorescent-antibody tests. The new species, unlike all other species except L. jordanis, did not require added L-cysteine for growth in serial transfer on charcoal-yeast extract agar. L. oakridgensis, as well as three other species tested, required L-cysteine for primary isolation from animal tissues. L. oakridgensis was the only species of Legionella that failed to produce alkaline phosphatase at pH 8.5. In all other respects, it resembled other species of Legionella, including having a high content of branched-chain cellular fatty acids and being pathogenic for guinea pigs. These bacteria have not yet been associated with human disease, but they are potential causes of legionellosis. PMID:6830217

  6. Concept of CFD model of natural draft wet-cooling tower flow

    NASA Astrophysics Data System (ADS)

    Hyhlík, T.

    2014-03-01

    The article deals with the development of CFD model of natural draft wet-cooling tower flow. The physical phenomena taking place within a natural draft wet cooling tower are described by the system of conservation law equations along with additional equations. The heat and mass transfer in the counterflow wet-cooling tower fill are described by model [1] which is based on the system of ordinary differential equations. Utilization of model [1] of the fill allows us to apply commonly measured fill characteristics as shown by [2].The boundary value problem resulting from the fill model is solved separately. The system of conservation law equations is interlinked with the system of ordinary differential equations describing the phenomena occurring in the counterflow wet-cooling tower fill via heat and mass sources and via boundary conditions. The concept of numerical solution is presented for the quasi one dimensional model of natural draft wet-cooling tower flow. The simulation results are shown.

  7. Cooling towers for combined cycles: Design philosophy, performance testing, and operating problems

    NASA Astrophysics Data System (ADS)

    Bauthier, J.

    The characteristics and parameters affecting the choice of a type of cooling tower and its installation in the circuit of a combined cycle are discussed. The different possibilities of water circuits that are encountered are defined. Two modes of exchange and two types of fill are discussed. The various types of wet towers are described and their advantages and disadvantages considered. Factors affecting the selection of a cooling tower include: cost of energy versus cost of tower; performances; water availability and quality; emissions (water, noise, air, and vapor); site locations; and operating conditions.

  8. Synthetic image generation of factory stack and cooling tower plumes

    NASA Astrophysics Data System (ADS)

    Kuo, Shiao D.; Schott, John R.

    1997-07-01

    A new model for generating synthetic images of plumes has been developed using a radiometrically based ray-tracing algorithm. Existing plume models that describe the characteristics of the plume (constituents, concentration, particulate sizing, and temperature) are used to generate AutoCAD models for input into the code. The effects of scattered light using Mie theory and radiative transfer, as well as thermal self-emission/absorption from within the plume, are modeled for different regions of the plume. The ray-tracing accounts for direct sunlight, scattered skylight, reflected sunlight from the background, and thermal self-emission from both the atmosphere and background. Synthetic generated images of a cooling tower plume, composed of water droplets, and a factor stack plume, composed of methyl chloride, are produced for visible, MWIR, and LWIR bands. Images of the plume from different view angles are also produced. Observations are made on the interaction between the plume and its background and possible effects for remote sensing. Images are made of the methyl chloride plume in which the concentration and temperature are varied to determine the sensitivity of the radiance reaching the sensor.

  9. 40 CFR 61.134 - Standard: Naphthalene processing, final coolers, and final-cooler cooling towers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... POLLUTANTS National Emission Standard for Benzene Emissions from Coke By-Product Recovery Plants § 61.134... are allowed from naphthalene processing, final coolers and final-cooler cooling towers at coke...

  10. 40 CFR 61.134 - Standard: Naphthalene processing, final coolers, and final-cooler cooling towers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... POLLUTANTS National Emission Standard for Benzene Emissions from Coke By-Product Recovery Plants § 61.134... are allowed from naphthalene processing, final coolers and final-cooler cooling towers at coke...

  11. 40 CFR 61.134 - Standard: Naphthalene processing, final coolers, and final-cooler cooling towers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... POLLUTANTS National Emission Standard for Benzene Emissions from Coke By-Product Recovery Plants § 61.134... are allowed from naphthalene processing, final coolers and final-cooler cooling towers at coke...

  12. 40 CFR 61.134 - Standard: Naphthalene processing, final coolers, and final-cooler cooling towers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... POLLUTANTS National Emission Standard for Benzene Emissions from Coke By-Product Recovery Plants § 61.134... are allowed from naphthalene processing, final coolers and final-cooler cooling towers at coke...

  13. 40 CFR 61.134 - Standard: Naphthalene processing, final coolers, and final-cooler cooling towers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... POLLUTANTS National Emission Standard for Benzene Emissions from Coke By-Product Recovery Plants § 61.134... are allowed from naphthalene processing, final coolers and final-cooler cooling towers at coke...

  14. ASSESSMENT OF THREE TECHNOLOGIES FOR THE TREATMENT OF COOLING TOWER BLOWDOWN

    EPA Science Inventory

    The report gives results of analyses of three methods for treating cooling tower blowdown: vapor compression evaporation (VCE), reverse osmosis (RO), and vertical tube foaming evaporation (VTFE). The two evaporative processes produce pure water (approximately 10 ppm dissolved sol...

  15. Cooling towers for combined cycles: New developments to meet environmental requirements

    NASA Astrophysics Data System (ADS)

    Vouche, M.; Bouton, F.; Lemmens, P.

    Two new developments in dry cooling systems are presented: the single row condenser (SRC) finned tube and the natural draft air-cooled condenser (NDC). The SRC tube is a flat finned tube based on a technology used for compact heat exchangers. This tube was specifically developed for vacuum air-cooled condensers. The serpentine fins of the SRC tube could be made in aluminum or in galvanized steel. The special technique of the brazing of the aluminum fins is described. A technical and economical comparison is made between the classical dry cooling equipment and the NDC. This comparison concludes with the high economic interest in combining the NDC and the single row design. The mechanical draught wet cooling towers with plume abatement are introduced and compared to classical parallel hybrid and reduced plume towers. The environmental impact of wet cooling towers is discussed with regard to heat and mass transfer, plume, bulkiness, and noise.

  16. Vertical sampling flights in support of the 1981 ASCOT cooling tower experiments: field effort and data

    SciTech Connect

    Gay, G.T.

    1982-03-01

    During the month of August 1981, three nights of experimental sampling of tracers released into the cooling tower plume of a geothermal power plant were conducted. In these experiments a tethered balloon was used to lift a payload so as to obtain vertical profiles of the cooling tower plume and the entrained tracers. A description of the equipment used, the field effort and the data acquired are presented here.

  17. Potentially pathogenic amoeba-associated microorganisms in cooling towers and their control.

    PubMed

    Pagnier, Isabelle; Merchat, Michèle; La Scola, Bernard

    2009-06-01

    Cooling towers provide a favorable environment for the proliferation of microorganisms. Cooling towers generate a biofilm and often aerosolize contaminated water, thereby increasing the risk of microorganism dissemination by human inhalation. This pathogen dissemination was first revealed by the epidemics of Legionnaires' disease that were directly related to the presence of cooling towers, and since then, the ecology of Legionella pneumophila has been well studied. Each country has specific standards regarding the acceptable amount of microorganisms in cooling tower systems. However, those standards typically only concern L. pneumophila, even though many other microorganisms can also be isolated from cooling towers, including protozoa, bacteria and viruses. Microbiological control of the cooling tower system can be principally achieved by chemical treatments and also by improving the system's construction. Several new treatments are being studied to improve the efficiency of disinfection. However, as most of these treatments continue to focus solely on L. pneumophila, reports of other types of pathogens continue to increase. Therefore, how their dissemination affects the human populous health should be addressed now. PMID:19492970

  18. Performance prediction of a multi-stage wind tower for indoor cooling

    NASA Astrophysics Data System (ADS)

    Issa, Roy J.; Chang, Byungik

    2012-08-01

    A theoretical model is developed to establish an in-depth understanding of the performance of a three-stage wind tower with a bypass system for indoor cooling in rural dry and hot climates. Model simulations are presented for a wide range of ambient conditions that include inlet wind speed, inlet temperature and relative humidity. Simulation results provide an insight into the desirable water flow rates and air-to-water loadings for comfort zone temperatures and relative humidity levels at the exit of the wind tower. Simulations show wind towers with variable cross-sections provide an increase in the cooling power for the same inlet wind speed, inlet air temperature and relative humidity when compared to wind towers with a constant cross-section. The study shall lead to a better understanding to designing wind towers that are both environmentally friendly and energy efficient.

  19. Measurement and characterization of emissions from a gas liquor fed cooling tower

    NASA Astrophysics Data System (ADS)

    Galegher, Sheila J.; Mann, Michael D.

    Phase I cooling tower testing at the University of North Dakota Energy Research Center (UNDERC) was designed to use solvent extracted and steam stripped wastewater from fixed-bed gasification of lignite as makeup. The objective of this test was to simulate the proposed mode of operation at the Great Plains Gasification Associates (GPGA) plant. A crucial part of this study was the characterization of emissions from a stripped gas liquor (SGL) fed cooling tower. Several types of sampling equipment including a multicyclone, cooled impingers, and an XAD resin trap were used for the collection and retention of components in the tower evaporate. Results of this study indicated that a significant portion of the phenol and ammonia, and also some methanol, in the tower makeup stream were stripped into the atmosphere. Concentration levels of 26,900 μg m -3 ammonia, 8000 μg m -3 phenol and 2500 μ m -3 methanol were detected in the lower exhaust.

  20. Engineering evaluation of magma cooling-tower demonstration at Nevada Power Company's Sunrise Station

    NASA Astrophysics Data System (ADS)

    1980-11-01

    The Magma Cooling Tower (MCT) process utilizes a falling film heat exchanger integrated into an induced draft cooling tower to evaporate waste water. A hot water source such as return cooling water provides the energy for evaporation. Water quality control is maintained by removing potential scaling constituents to make concentrations of the waste water possible without scaling heat transfer surfaces. A pilot-scale demonstration test of the MCT process was performed from March 1979 through June 1979 at Nevada Power Company's Sunrise Station in Las Vegas, Nevada. The pilot unit extracted heat from the powerplant cooling system to evaporate cooling tower blowdown. Two water quality control methods were employed: makeup/sidestream softening and fluidized bed crystallization. The 11 week softening mode test was successful.

  1. Effect of solar radiation on the performance of cross flow wet cooling tower in hot climate of Iran

    NASA Astrophysics Data System (ADS)

    Banooni, Salem; Chitsazan, Ali

    2016-01-01

    In some cities such as Ahvaz-Iran, the solar radiation is very high and the annual-mean-daily of the global solar radiation is about 17.33 MJ m2 d-1. Solar radiation as an external heat source seems to affect the thermal performance of the cooling towers. Usually, in modeling cooling tower, the effects of solar radiation are ignored. To investigate the effect of sunshade on the performance and modeling of the cooling tower, the experiments were conducted in two different states, cooling towers with and without sunshade. In this study, the Merkel's approach and finite difference technique are used to predict the thermal behavior of cross flow wet cooling tower without sunshade and the results are compared with the data obtained from the cooling towers with and without sunshade. Results showed that the sunshade is very efficient and it reduced the outlet water temperature, the approach and the water exergy of the cooling tower up to 1.2 °C, 15 and 1.1 %, respectively and increased the range and the efficiency of the cooling tower up to 29 and 37 %, respectively. Also, the sunshade decreased the error between the experimental data of the cooling tower with sunshade and the modeling results of the cooling tower without sunshade 1.85 % in average.

  2. Disinfection of bacterial biofilms in pilot-scale cooling tower systems

    PubMed Central

    Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P.; Packman, Aaron I.

    2015-01-01

    The impact of continuous chlorination and periodic glutaraldehyde treatment on planktonic and biofilm microbial communities was evaluated in pilot-scale cooling towers operated continuously for 3 months. The system was operated at a flow rate of 10,080 l day−1. Experiments were performed with a well-defined microbial consortium containing three heterotrophic bacteria: Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. The persistence of each species was monitored in the recirculating cooling water loop and in biofilms on steel and PVC coupons in the cooling tower basin. The observed bacterial colonization in cooling towers did not follow trends in growth rates observed under batch conditions and, instead, reflected differences in the ability of each organism to remain attached and form biofilms under the high-through flow conditions in cooling towers. Flavobacterium was the dominant organism in the community, while P. aeruginosa and K. pneumoniae did not attach well to either PVC or steel coupons in cooling towers and were not able to persist in biofilms. As a result, the much greater ability of Flavobacterium to adhere to surfaces protected it from disinfection, whereas P. aeruginosa and K. pneumoniae were subject to rapid disinfection in the planktonic state. PMID:21547755

  3. Disinfection of bacterial biofilms in pilot-scale cooling tower systems.

    PubMed

    Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron I

    2011-04-01

    The impact of continuous chlorination and periodic glutaraldehyde treatment on planktonic and biofilm microbial communities was evaluated in pilot-scale cooling towers operated continuously for 3 months. The system was operated at a flow rate of 10,080 l day(-1). Experiments were performed with a well-defined microbial consortium containing three heterotrophic bacteria: Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. The persistence of each species was monitored in the recirculating cooling water loop and in biofilms on steel and PVC coupons in the cooling tower basin. The observed bacterial colonization in cooling towers did not follow trends in growth rates observed under batch conditions and, instead, reflected differences in the ability of each organism to remain attached and form biofilms under the high-through flow conditions in cooling towers. Flavobacterium was the dominant organism in the community, while P. aeruginosa and K. pneumoniae did not attach well to either PVC or steel coupons in cooling towers and were not able to persist in biofilms. As a result, the much greater ability of Flavobacterium to adhere to surfaces protected it from disinfection, whereas P. aeruginosa and K. pneumoniae were subject to rapid disinfection in the planktonic state. PMID:21547755

  4. Fouling characteristics of cooling tower water containing corrosion inhibitors

    SciTech Connect

    Santoso, E.

    1987-01-01

    Corrosion inhibitors investigated included zinc-chromate and phosphates. In addition, additives including polyacrylate and phosphonate (HEDP and AMP) were used to determine their effectiveness as antifoulants. The tests were conducted in a simulated cooling tower water system. The parameters investigated were: test section surface temperature 130, 145 and 160{degree}F, velocity in test section 3.0, 5.5 and 8.5 ft/sec, pH 6.0 -8.0, and material of the fouling surface (stainless steel, carbon steel, 90/10 copper/nickel, and admiralty brass). The water bulk temperature in all tests was 115{degree}F. The water had a total hardness of 800-1000 ppm as CaCO{sub 3}, total sulfate of 800-1000 ppm as SO{sub 4} and silica of 40-45 ppm as SiO{sub 2}. For each test, a fouling resistance - time curve was obtained. This curve was fitted to the equation Rf = Rf (1-exp(-({theta}-{theta}d)/{theta}c)) to yield the values of {theta}c and Rf{sup *}. Rf is the fouling resistance predicted by the regression equation, Rf{sup *} is the asymptotic fouling resistance, {theta} is time, {theta}d is dead time and {theta}c is the time constant for the asymptotic decay. The values of {theta}c and Rf{sup *} from regression analysis have been correlated with the various parameters by the Heat Transfer Research, Inc., (HTRI) fouling model. For the range of conditions studied, the correlation equations relate the fouling resistance, Rf, to the surface temperature, wall shear stress and water quality. Seventeen different water qualities were investigated to determine the values of 5 parameters, which are specific for each water quality. For each of the seventeen water qualities studied threshold curves for three threshold values of Rf{sup *} have been developed as a function of velocity and surface temperature. These curves are useful to obtain the conditions required to maintain a desired value of Rf{sup *} in a heat exchanger.

  5. A case of nosocomial Legionella pneumonia associated with a contaminated hospital cooling tower.

    PubMed

    Osawa, Kayo; Shigemura, Katsumi; Abe, Yasuhisa; Jikimoto, Takumi; Yoshida, Hiroyuki; Fujisawa, Masato; Arakawa, Soichi

    2014-01-01

    We report the epidemiological investigation of a nosocomial pneumonia case due to Legionella pneumophila linked to a contaminated hospital cooling tower in an immune-compromised patient. A 73-year-old female patient was diagnosed with nosocomial Legionella pneumonia proven by a culture of L. pneumophila serogroup 1 from bronchoalveolar lavage fluid. Two strains isolated from the patient and two strains isolated from two cooling towers were found to be identical using repetitive-sequence-based-PCR with a 95% probability. This Legionella pneumonia case might be caused by aerosol from cooling towers on the roof of the hospital building which was contaminated by L. pneumophila. We increased up the temperature of hot water supply appropriately for prevention of Legionella breeding in an environment of patients' living. On the other hand, as the maintenance of cooling tower, we increased the frequency of Legionella culture tests from twice a year to three times a year. In addition, we introduced an automated disinfectants insertion machine and added one antiseptic reagent (BALSTER ST-40 N, Tohzai Chemical Industry Co., Ltd., Kawasaki, Japan) after this Legionella disease, and thereafter, we have no additional cases of Legionella disease or detection of Legionella spp. from the cooling tower or hot water supply. This case demonstrates the importance of detecting the infection source and carrying out environmental maintenance in cooperation with the infection control team. PMID:24462430

  6. Emissions characteristics of cooling towers using reclaimed wastewater in california. Final report, July 1979-July 1981

    SciTech Connect

    Rogozen, M.B.; Phillips, A.R.; Guttman, M.A.; Shokes, R.F.; Fargo, L.

    1981-08-11

    Present and planned use of reclaimed municipal wastewater, industrial process water, and geothermal condensate as makeup to cooling towers have raised questions about the potential for atmospheric emissions of pathogenic microorganisms, organic compounds, heavy metals, and other wastewater constituents. In this study, the makeup and circulating water of six towers were sampled and analyzed for indicator bacteria and virus, volatile and nonvolatile organic compounds, metals, and other components of potential concern. Further water sampling and exhaust air emissions tests were then conducted on four of the towers; for the microbiological emissions tests, a special isokinetic sampling device was developed and employed.

  7. Assessing the environmental health relevance of cooling towers--a systematic review of legionellosis outbreaks.

    PubMed

    Walser, Sandra M; Gerstner, Doris G; Brenner, Bernhard; Höller, Christiane; Liebl, Bernhard; Herr, Caroline E W

    2014-03-01

    Bioaerosols from cooling towers are often suspected to cause community-acquired legionellosis outbreaks. Although Legionella infections can mostly be assigned to the emission sources, uncertainty exists about the release and distribution into the air, the occurrence of the respirable virulent form and the level of the infective concentration. Our study aimed to evaluate studies on legionellosis outbreaks attributed to cooling towers published within the last 11 years by means of a systematic review of the literature. 19 legionellosis outbreaks were identified affecting 12 countries. Recurring events were observed in Spain and Great Britain. In total, 1609 confirmed cases of legionellosis and a case-fatality rate of approximately 6% were reported. Duration of outbreaks was 65 days on average. For diagnosis the urinary antigen test was mainly used. Age, smoking, male sex and underlying diseases (diabetes, immunodeficiency) could be confirmed as risk factors. Smoking and underlying diseases were the most frequent risk factors associated with legionellosis in 11 and 10 of the 19 studies, respectively. The meteorological conditions varied strongly. Several studies reported a temporal association of outbreaks with inadequate maintenance of the cooling systems. A match of clinical and environmental isolates by serotyping and/or molecular subtyping could be confirmed in 84% of outbreaks. Legionella-contaminated cooling towers as environmental trigger, in particular in the neighbourhood of susceptible individuals, can cause severe health problems and even death. To prevent and control Legionella contamination of cooling towers, maintenance actions should focus on low-emission cleaning procedures of cooling towers combined with control measurements of water and air samples. Procedures allowing rapid detection and risk assessment in the case of outbreaks are essential for adequate public health measures. Systematic registration of cooling towers will facilitate the

  8. CFD MODELING AND ANALYSIS FOR A-AREA AND H-AREA COOLING TOWERS

    SciTech Connect

    Lee, S.; Garrett, A.; Bollinger, J.

    2009-09-02

    Mechanical draft cooling towers are designed to cool process water via sensible and latent heat transfer to air. Heat and mass transfer take place simultaneously. Heat is transferred as sensible heat due to the temperature difference between liquid and gas phases, and as the latent heat of the water as it evaporates. Mass of water vapor is transferred due to the difference between the vapor pressure at the air-liquid interface and the partial pressure of water vapor in the bulk of the air. Equations to govern these phenomena are discussed here. The governing equations are solved by taking a computational fluid dynamics (CFD) approach. The purpose of the work is to develop a three-dimensional CFD model to evaluate the flow patterns inside the cooling tower cell driven by cooling fan and wind, considering the cooling fans to be on or off. Two types of the cooling towers are considered here. One is cross-flow type cooling tower located in A-Area, and the other is counterflow type cooling tower located in H-Area. The cooling tower located in A-Area is mechanical draft cooling tower (MDCT) consisting of four compartment cells as shown in Fig. 1. It is 13.7m wide, 36.8m long, and 9.4m high. Each cell has its own cooling fan and shroud without any flow communications between two adjacent cells. There are water distribution decks on both sides of the fan shroud. The deck floor has an array of about 25mm size holes through which water droplet falls into the cell region cooled by the ambient air driven by fan and wind, and it is eventually collected in basin area. As shown in Fig. 1, about 0.15-m thick drift eliminator allows ambient air to be humidified through the evaporative cooling process without entrainment of water droplets into the shroud exit. The H-Area cooling tower is about 7.3 m wide, 29.3 m long, and 9.0 m high. Each cell has its own cooling fan and shroud, but each of two corner cells has two panels to shield wind at the bottom of the cells. There is some

  9. Concentration, serotypic profiles, and infectivity of Legionnaires' Disease bacteria populations in cooling towers

    SciTech Connect

    Tyndall, R.L.

    1982-01-01

    At the Philadelphia American Legion Convention in 1976 nearly two hundred people developed pulmonary infection. Of these, twenty-eight died. The causative bacterial agent was subsequently isolated and identified as a previously undiscovered human pathogen, that is, Legionnaires' Disease Bacterium (LDB). Currently it is estimated that over one hundred thousand cases of Legionella occur annually. Cooling towers have been shown to be the source of LDB in some of the outbreaks. Ecological information indicates that the bacteria are present in many natural waters. Moreover, there is strong evidence that algal products can stimulate the growth of LDB. Because cooling tower environments may be conducive for growth and/or dispersal of LDB, a survey of both industrial and air-conditioning cooling towers for the presence of LDB was undertaken.

  10. Application of the hampel's method to approximate a theoretical model of the cooling tower in the two-dimensional approach. (Polish Title: Zastosowanie metody Hampela do aproksymacji modelu teoretycznego chłodni kominowej w podejściu dwuwymiarowym)

    NASA Astrophysics Data System (ADS)

    Muszyński, Z.

    2013-12-01

    Correct assessment of construction safety requires reliable information about geometrical shape of the analyzed object. The least square method is the most popular method to calculate object deviation between theoretical geometry and the real object shape measured with geodetic methods. The paper presents the possibility of using robust estimation methods on the example of Hampel's method. Deviation values obtained in this way are resistant to outliers influence and are more reliable. This problem is illustrated by a hyperbola which is approximated in survey points (measured by terrestrial laser scanning) localized on the generating line of the cooling tower shell in one of its axial vertical cross-section.

  11. Biocide usage in cooling towers in the electric power and petroleum refining industries

    SciTech Connect

    Veil, J.; Rice, J.K.; Raivel, M.E.S.

    1997-11-01

    Cooling towers users frequently apply biocides to the circulating cooling water to control growth of microorganisms, algae, and macroorganisms. Because of the toxic properties of biocides, there is a potential for the regulatory controls on their use and discharge to become increasingly more stringent. This report examines the types of biocides used in cooling towers by companies in the electric power and petroleum refining industries, and the experiences those companies have had in dealing with agencies that regulate cooling tower blowdown discharges. Results from a sample of 67 electric power plants indicate that the use of oxidizing biocides (particularly chlorine) is favored. Quaternary ammonia salts (quats), a type of nonoxidizing biocide, are also used in many power plant cooling towers. The experience of dealing with regulators to obtain approval to discharge biocides differs significantly between the two industries. In the electric power industry, discharges of any new biocide typically must be approved in writing by the regulatory agency. The approval process for refineries is less formal. In most cases, the refinery must notify the regulatory agency that it is planning to use a new biocide, but the refinery does not need to get written approval before using it. The conclusion of the report is that few of the surveyed facilities are having any difficulty in using and discharging the biocides they want to use.

  12. Experimental measurement of cooling tower emissions using image processing of sensitive papers

    NASA Astrophysics Data System (ADS)

    Ruiz, J.; Kaiser, A. S.; Ballesta, M.; Gil, A.; Lucas, M.

    2013-04-01

    Cooling tower emissions are harmful for several reasons such as air polluting, wetting, icing and solid particle deposition, but mainly due to human health hazards (i.e. Legionella). There are several methods for measuring drift drops. This paper is focussed on the sensitive paper technique, which is suitable in low drift scenarios and real conditions. The lack of an automatic classification method motivated the development of a digital image process algorithm for the Sensitive Paper method. This paper presents a detailed description of this method, in which, drop-like elements are identified by means of the Canny edge detector combined with some morphological operations. Afterwards, the application of a J48 decision tree is proposed as one of the most relevant contributions. This classification method allows us to discern between stains whose origin is a drop and stains whose origin is not a drop. The method is applied to a real case and results are presented in terms of drift and PM10 emissions. This involves the calculation of the main features of the droplet distribution at the cooling tower exit surface in terms of drop size distribution data, cumulative mass distribution curve and characteristic drop diameters. The Log-normal and the Rosin-Rammler distribution functions have been fitted to the experimental data collected in the tests and it can been concluded that the first one is the most suitable for experimental data among the functions tested (whereas the second one is less suitable). Realistic PM10 calculations include the measurement of drift emissions and Total Dissolved Solids as well as the size and number of drops. Results are compared to the method proposed by the U.S. Environmental Protection Agency assessing its overestimation. Drift emissions have found to be 0.0517% of the recirculating water, which is over the Spanish standards limit (0.05%).

  13. Startup of air-cooled condensers and dry cooling towers at low temperatures of the cooling air

    NASA Astrophysics Data System (ADS)

    Milman, O. O.; Ptakhin, A. V.; Kondratev, A. V.; Shifrin, B. A.; Yankov, G. G.

    2016-05-01

    The problems of startup and performance of air-cooled condensers (ACC) and dry cooling towers (DCT) at low cooling air temperatures are considered. Effects of the startup of the ACC at sub-zero temperatures are described. Different options of the ACC heating up are analyzed, and examples of existing technologies are presented (electric heating, heating up with hot air or steam, and internal and external heating). The use of additional heat exchanging sections, steam tracers, in the DCT design is described. The need for high power in cases of electric heating and heating up with hot air is noted. An experimental stand for research and testing of the ACC startup at low temperatures is described. The design of the three-pass ACC unit is given, and its advantages over classical single-pass design at low temperatures are listed. The formation of ice plugs inside the heat exchanging tubes during the start-up of ACC and DCT at low cooling air temperatures is analyzed. Experimental data on the effect of the steam flow rate, steam nozzle distance from the heat-exchange surface, and their orientation in space on the metal temperature were collected, and test results are analyzed. It is noted that the surface temperature at the end of the heat up is almost independent from its initial temperature. Recommendations for the safe start-up of ACCs and DCTs are given. The heating flow necessary to sufficiently heat up heat-exchange surfaces of ACCs and DCTs for the safe startup is estimated. The technology and the process of the heat up of the ACC with the heating steam external supply are described by the example of the startup of the full-scale section of the ACC at sub-zero temperatures of the cooling air, and the advantages of the proposed start-up technology are confirmed.

  14. Pilot-scale cooling tower to evaluate corrosion, scaling, and biofouling control strategies for cooling system makeup water.

    PubMed

    Chien, S H; Hsieh, M K; Li, H; Monnell, J; Dzombak, D; Vidic, R

    2012-02-01

    Pilot-scale cooling towers can be used to evaluate corrosion, scaling, and biofouling control strategies when using particular cooling system makeup water and particular operating conditions. To study the potential for using a number of different impaired waters as makeup water, a pilot-scale system capable of generating 27,000 kJ∕h heat load and maintaining recirculating water flow with a Reynolds number of 1.92 × 10(4) was designed to study these critical processes under conditions that are similar to full-scale systems. The pilot-scale cooling tower was equipped with an automatic makeup water control system, automatic blowdown control system, semi-automatic biocide feeding system, and corrosion, scaling, and biofouling monitoring systems. Observed operational data revealed that the major operating parameters, including temperature change (6.6 °C), cycles of concentration (N = 4.6), water flow velocity (0.66 m∕s), and air mass velocity (3660 kg∕h m(2)), were controlled quite well for an extended period of time (up to 2 months). Overall, the performance of the pilot-scale cooling towers using treated municipal wastewater was shown to be suitable to study critical processes (corrosion, scaling, biofouling) and evaluate cooling water management strategies for makeup waters of complex quality. PMID:22380105

  15. Experimental optimization of cooling-tower-fan control based on field data. Master's thesis

    SciTech Connect

    Herman, D.L.

    1991-04-01

    Energy costs continue to play an important role in the decision-making process for building design and operation. Since the chiller, cooling tower fans, and associated pumps consume the largest fraction of energy in a heating, ventilating, and air-conditioning (HVAC) system, the control of these components is of major importance in determining building energy use. A significant control parameter for the chilled water system is the minimum entering condenser water set point temperature at which the cooling tower fans are cycled on and off, several studies have attempted to determine the optimum value for this minimum set point temperature, but direct measurements are not available to validate these studies. The purpose of this study was to experimentally determine the optimum minimum entering condenser water set point temperature from field data based on minimum energy consumption and to validate a chilled water system analytical model previously developed in earlier work. The total chiller system electrical consumption (chiller and cooling tower fan energy) was measured for four entering condensor water set point temperatures (70, 75, 80, and 85 deg F). The field results were compared to results obtained using an analytical model previously developed in a thesis entitled Optimized Design of a Commercial Building Chiller/Cooling Tower System, written by Joyce.

  16. On-line performance monitoring of the natural draft cooling tower at Cardinal Plant

    SciTech Connect

    Michell, F.L.; Miller, M.J.

    1998-12-31

    The paper will provide an overview of the on-line performance monitoring system recently installed on the 630MW coal fired Unit 3 at the Cardinal Plant. Experience with using the on-line monitor to optimize performance of the major circulating water system components including the pumps, condensers and cooling tower will be discussed in the paper.

  17. PBF Cooling Tower (PER720). Camera faces south to show north ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower (PER-720). Camera faces south to show north facade. Note enclosed stairway. Date: August 2003. INEEL negative no. HD-35-10-3 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  18. PBF Cooling Tower (PER720) and its Auxiliary Building (PER625). Camera ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower (PER-720) and its Auxiliary Building (PER-625). Camera facing west shows east facades. Center pipe carried secondary coolant water from reactor. Building to distributor basin. Date: August 2003. INEEL negative no. HD-35-10-1 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  19. PBF Cooling Tower (PER720). Closeup detail of louvered wall panels ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower (PER-720). Close-up detail of louvered wall panels on south facade. Date: August 2003. INEEL negative no. HD-35-11-1 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  20. In Situ g-PHA Measurements of the 285-3H Cooling Tower Components

    SciTech Connect

    Salaymeh, S.R.

    2001-05-23

    The Analytical Development Section of Savannah River Technology Center was requested by the Facility Disposition Division to conduct in-situ gamma-ray pulse height analysis measurements to provide input toward the decision to unconditionally release the 285-3H cooling tower.

  1. PBF Cooling Tower (PER720), and Auxiliary Building (PER624). Camera faces ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower (PER-720), and Auxiliary Building (PER-624). Camera faces north to show south facades. Oblong vertical structure at left of center is weather shield for stairway. Date: August 2003. INEEL negative no. HD-35-10-4 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  2. Prevalence of Legionella strains in cooling towers and legionellosis cases in New Zealand.

    PubMed

    Lau, Robert; Maqsood, Saadia; Harte, David; Caughley, Brian; Deacon, Rob

    2013-01-01

    Over 3,900 water samples from 688 cooling towers were tested for Legionella in 2008 in New Zealand. Of 80 (2.05% isolation rate) Legionella isolates, 10 (12.5%) were L. pneumophila serogroup 1; 10 (12.5%) were L. anisa; nine (11.2%) were L. pneumophila serogroup 8; and one (1.2%) was L. longbeachae serogroup 2. Forty-one (51.2%) Legionella isolates were L. pneumophila serogroups. Over 3,990 water samples from 606 cooling towers were tested for Legionella in 2009 in New Zealand. Of 51 (1.28% isolation rate) Legionella isolates, 18 (35.3%) were L. pneumophila serogroup 1, and 39 (76.4%) were other L. pneumophila serogroups. L. pneumophila serogroups were significantly associated with legionellosis cases in 2008 and 2009. L. longbeachae serogroups were equally significantly associated with legionellosis cases. This significant association of L. longbeachae with legionellosis particularly of L. longbeachae serogroup 1 is unique in that part of the world. The authors' study also showed that the aqueous environment of the cooling tower is not a natural habitat for pathogenic L. longbeachae. Regular monitoring and maintenance of cooling towers have prevented outbreaks of legionellosis. PMID:23397654

  3. ETR COOLING TOWER PUMP HOUSE, TRA645. FOUR SECONDARY COOLANT PUMPS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ETR COOLING TOWER PUMP HOUSE, TRA-645. FOUR SECONDARY COOLANT PUMPS ARE ARRANGED IN A ROW. IN REAR ARE THREE SHUTDOWN EMERGENCY PUMPS. INL NEGATIVE NO. 56-4176. Jack L. Anderson, Photographer, 12/21/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  4. TESTING AND ANALYSIS OF A WET-DRY CROSSFLOW COOLING TOWER, VOLUME II: APPENDICES

    EPA Science Inventory

    The report discusses the test program and performance analysis of a single-cell mechanical-draft wet/dry cooling tower in Cliffside, NC. Objectives of the program were to obtain performance data and results on mass transfer, heat transfer, fluid flow, plume formation, and acousti...

  5. Evaluation and quantification of the impact of cooling tower emissions on indoor air quality

    SciTech Connect

    Vanderheyden, M.D.; Schuyler, G.D.

    1994-12-31

    Assessment of the potential impact of outdoor pollutant sources on indoor air quality through the reentrainment of pollutants vis-a-vis air-handling units, doorways, and windows has mainly focused on the evaluation of fume hood, boiler, diesel generator, and vehicular pollutant emissions. In recent years, however, gaseous and waterborne pollutants emitted from cooling towers have become an increasing source of concern. Chemicals such as biocides and corrosion and scale inhibitors are used to reduce and/or eliminate algae blooms, decrease bacterial and fungal growth, and reduce the corrosion of equipment. When added to the water used in cooling towers, these chemicals are emitted in both the gaseous phase and as pollutants dissolved in or suspended in water droplets. A qualitative evaluation of exhaust dispersion and droplet deposition rates associated with cooling towers is necessary when conducting an overall review of the environmental impact on indoor air quality. This paper identifies source emission rates to be used in assessing emissions of chemical additives in cooling towers, presents provisional design criteria for evaluating the impact of the chemical additives, and evaluates alternative methodologies for quantifying impact concentrations. These alternative assessment methodologies include numerical models, physical wind tunnel simulations, and computational fluid dynamics (CFD) simulations. Parameters used in comparing the methodologies include relative accuracy (order of magnitude) and modeling and simulation limitations.

  6. Pilot-scale treatment of gasification wastewater and reuse in a cooling tower

    SciTech Connect

    Willson, W.G.; Mayer, G.G.; Hendrikson, J.G.; Winton, S.L.

    1985-04-01

    The University of North Dakota Energy Research Center has operated a 910 kg/hr, oxygen-blown fixed-bed gasifier to produce lignite-derived effluents for characterization, treatment, and reuse studies. Reuse of waste water in a cooling tower was investigated to define environmental and process effects as a function of pretreatment. The gasification wastewater was pretreated in pilot wastewater treatement units which simulate available technology. During the first phase of the program, wastewater was pretreated by solvent extraction and steam stripping to produce phenol and ammonia concentrations comparable to those expected at the Great Plains Gasification Associates plant. This pretreated wastewater was concentrated in a cooling tower to 10 cycles of concentration. No biocides or corrosion inhibitors were added. Severe fouling of heat exchange surfaces and high corrosion rates of carbon steel were encountered. Over 90% of the phenol entering the cooling tower was found to be stripped into the cooling tower exhaust air stream. The high levels of organics remaining in this minimally treated wastewater suggested that further biological treatment and possibly polishing by carbon adsorption would be necessary to prepare a satisfactory feed. In the second phase of the program, the SGL was further treated in an activated sludge process followed by granular activated carbon adsorption. Biotreatment removed 96% of the BOD with a three-day retention time while obtaining satisfactory sludge settling rates in spite of varied influent concentrations. Biorefractory materials were adsorbed on GAC to reach an effuent COD level of 150 mg/l. This upgrading was sufficient to reduce organic emissions from the cooling tower, but corrosion rates were higher than in the previous test, again showing the necessity for corrosion inhibitors. 8 figs., 3 tabs.

  7. Magnetic fluid conditioning system allows 3000 ppm hardness without cooling tower scale buildup

    SciTech Connect

    Szostak, R.J.; Toy, D.A.

    1985-08-01

    Big Three Industries, a manufacturer of compressed and liquefied atmospheric gases, operates a large production complex in Bayport, TX which recirculates 100,000 gpm cooling water. Due to regulatory agency guidelines, high costs, and limited effectiveness of conventional chemical treatment methods, Big Three was in need of a treatment method to prevent corrosion and scaling in recirculating water cooling systems. In December 1983 a magnetic fluid conditioner (MFC) was installed in the pump discharge piping of one cooling tower at Bayport. The patented MFC is an 18'' long spool pipe fitted with uranium-based alloy magnets. The MFC has no moving parts and requires no chemicals, external power source, or maintenance. The MFC is designed so that the fluid is accelerated through a magnetic field. The high velocity of the fluid causes nucleation of the salts in the fluid. The salts are separated from the water by precipitation. During eighteen months of using the MFC, the cooling tower has concentrated in excess of 50 cycles. Conductivity is in excess of 10,000 micromhos, and total hardness (CaCO/sub 3/) is above 4000 ppm with pH stabilized between 8 and 9. However, inspections have revealed clean surfaces. The cleaner metal surfaces within the cooling water system provide better heat transfer which has resulted in reduction of tower blowdown, makeup water requirements, and pumping costs. Associated savings will enable the MFC to achieve payback in two and a half years.

  8. Field trial of biocides for control of Legionella in cooling towers.

    PubMed

    Bentham, R H; Broadbent, C R

    1995-03-01

    Legionella and amebae populations in 16 cooling towers were challenged with three commercially available biocide formulations. The active agents were: a chlorinated phenolic thioether (CPTE), bromo-nitro-propane-diol (BNPD), and bromo-chloro-dimethylhydantoin (BCD, in briquette form). The towers were dosed with these biocides for approximately 4 weeks. BCD was effective against Legionella in each of nine challenge experiments, and CPTE in eight of nine challenges. BNPD was effective in only five of 11 challenges. None of the biocides had any significant effect in reducing planktonic amebae concentrations during the challenges. PMID:7765850

  9. An investigation of the operating efficiency of coking plant ventilator cooling towers

    SciTech Connect

    Mizin, V.A.; Mamrosov, A.D.; Chernyshov, A.A.; Kolivashko, A.S.; Merinkov, V.V.; Romas, V.P.; Kovalenko, V.P.

    1982-01-01

    A discussion was given on the problems of clogging of spray nozzles in cooling towers. With continued use, a thick layer of deposits begin to form, first changing the spray pattern, and then clogging the nozzle completely.A study was done on the change in efficiency of tower sections as a function of their service time since overhaul. This proved the correlation between efficiency and spray pattern. Also, a description of a new sprayer for improved efficiency and reliability was given. Some operational data on the new distributors was given showing a reduced operation cost. Three tables of data were included.

  10. A STUDY ON LEGIONELLA PNEUMOPHILA, WATER CHEMISTRY, AND ATMOSPHERIC CONDITIONS IN COOLING TOWERS AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Smith, C.; Brigmon, R.

    2009-10-20

    Legionnaires disease is a pneumonia caused by the inhalation of the bacterium Legionella pneumophila. The majority of illnesses have been associated with cooling towers since these devices can harbor and disseminate the bacterium in the aerosolized mist generated by these systems. Historically, Savannah River Site (SRS) cooling towers have had occurrences of elevated levels of Legionella in all seasons of the year and in patterns that are difficult to predict. Since elevated Legionella in cooling tower water are a potential health concern a question has been raised as to the best control methodology. In this work we analyze available chemical, biological, and atmospheric data to determine the best method or key parameter for control. The SRS 4Q Industrial Hygiene Manual, 4Q-1203, 1 - G Cooling Tower Operation and the SRNL Legionella Sampling Program, states that 'Participation in the SRNL Legionella Sampling Program is MANDATORY for all operating cooling towers'. The resulting reports include L. pneumophila concentration information in cells/L. L. pneumophila concentrations >10{sup 7} cells/L are considered elevated and unsafe so action must be taken to reduce these densities. These remedial actions typically include increase biocide addition or 'shocking'. Sometimes additional actions are required if the problem persists including increase tower maintenance (e.g. cleaning). Evaluation of 14 SRS cooling towers, seven water quality parameters, and five Legionella serogroups over a three-plus year time frame demonstrated that cooling tower water Legionella densities varied widely though out this time period. In fact there was no one common consistent significant variable across all towers. The significant factors that did show up most frequently were related to suspended particulates, conductivity, pH, and dissolved oxygen, not chlorine or bromine as might be expected. Analyses of atmospheric data showed that there were more frequent significant elevated Legionella

  11. Calder Hall Cooling Tower Demolition: Landmark Milestone for Decommissioning at Sellafield

    SciTech Connect

    Williamson, E.J.

    2008-07-01

    September 2007 saw a very visible change to the Sellafield site following the culmination of a major decommissioning project; the demolition of the four Calder Hall cooling towers. A key part of the UK's nuclear industrial heritage, Calder Hall, the world's first commercial nuclear power station, was opened by Her Majesty Queen Elizabeth II in October 1953 and continued to generate electricity until its closure in 2003. Following the decision to decommission the Calder Hall site, explosive demolition was identified as the safest and most cost effective route for the removal of the towers. The technique, involving the placement of explosive in 60% of the circumference of both shell and legs, is a tried and tested method which had already been used successfully in more than 200 cooling towers in the UK in the last 30 years. The location and composition of the four 88 metre high towers also created additional challenges. Situated only 40 metres away from the UK's only nuclear Fuel Handling Plant, as well as other sensitive structures on the Sellafield site, the project had to address the impact of a number of key areas, including dust, ground vibration and air over pressure, to ensure that the demolition could be carried out safely and without significant impact on other operational areas on the site. At the same time, the towers had to be prepared for demolition in a way that minimised the amounts of radioactive or hazardous waste materials arising. This paper follows the four year journey from the initial decision to demolish the towers right through to the demolition itself as well as the clean up of the site post demolition. It will also consider the massive programme of work necessary not only to carry out the physical work safely but also to gain regulatory confidence and stakeholder support to carry out the project successfully. In summary: The demolition of the four Calder Hall cooling towers was a highly visible symbol of the changes that are occurring on the

  12. An ultrasensitive fouling monitoring system for cooling towers

    SciTech Connect

    Nohata, Y.; Taguchi, H.

    1995-03-01

    Fouling in industrial water has been a serious problem for many years. For example, the deterioration of the efficiency of heat exchangers and the occurrence of corrosion can cause cooling water leakage into the process streams. Biocides, dispersants, and filtration systems typically are used to prevent these problems. However, if these treatment programs are started too late, the early stages of fouling can occur. Here, a simple method for assessing fouling and chemical treatment efficiency is described. An ultrasensitive fouling sensor that uses piezoelectric quartz crystals was developed which detects fouling in the early stages.

  13. Real world energy performance a look at chiller/cooling tower performance

    SciTech Connect

    Schmitt, R.W.

    1996-12-31

    Traditional selection criteria for chillers has focused on the chiller kW/ton at full-load design conditions, with little or no attention paid to part-load or off-design conditions. This is beginning to change because part-load or off-design conditions account for approximately 98% of chiller operating hours. With a multiple chiller central plant, part-load conditions mean running one or more chillers at or near peak capacity, with the other chillers off. This usually occurs in the fall, winter and spring, or during evening and nighttime hours, when outdoor air temperatures are lower. Consequently, entering condenser water temperatures below design are available. This paper will look at the economies of taking advantage of these conditions, and spend time looking at cooling tower selections. Cooling towers are relatively inexpensive when compared to chillers, and it often makes sense to use a higher capacity tower and lower the design entering condenser water temperature to the chiller. Improved chiller efficiencies will offset the additional tower cost and fan power.

  14. Optimization research on the structure of horizontally-arranged indirect air-cooling tower under strong wind condition

    NASA Astrophysics Data System (ADS)

    Chen, Guoyong; Gu, Hongfang; Wang, Haijun; Qin, Yongbo

    2013-07-01

    Strong wind has a significant impact on the heat radiation of the air-cooling system. In this research, a numerical calculation model of 2×1000MW horizontally arranged air-cooling tower is established to simulate the flow distribution and heat exchanging capability of three different structures-horizontally-arranged indirect air-cooling tower, tower with guide wall outside, and tower with a cross wall inside-under high-speed wind and extreme-speed wind conditions. The result reveals that the structure with the guide wall outside the tower only works under strong wind condition while the structure with cross wall inside shows the anti-wind capability under both high-speed wind and extreme-speed wind conditions.

  15. Reuse of pretreated coal gasification condensate in a pilot scale cooling tower

    SciTech Connect

    Johnson, M.D.; Schweitzer, G.W.

    1987-01-01

    The recycle of wastewaters to cooling water systems is practiced in many industrial sectors. The Great Plains Gasification Plant (GPGP) located near Beulah, North Dakota, for example, was designed to reuse treated gas liquor as the primary source of makeup water. In other industrial plants, the concentration of contaminants in the makeup water is very low or the wastewater comprises only a small fraction of the total makeup to the cooling system. The Great Plains system is unique in that the stripped gas liquor (SGL) used as makeup contains relatively high concentrations of dissolved organics, ammonia and acid gases. In addition, the SGL constitutes over 90% of the total makeup to the system. The use of pretreated gas liquor in open, circulating cooling systems is an untried approach to wastewater recycle. The plant not only eliminates a large discharge problem but gains a valuable makeup source for the cooling towers. Because of the large heat duties for the cooling system in these types of plants and their location of regions of water shortages, this approach can be very beneficial. However, there are several environmental and operational concerns that have yet to be resolved. These include atmospheric emissions, fouling of heat transfer surfaces and cooling tower equipment, and excessive corrosion of system components.

  16. Reliability Analysis of Cooling Towers: Influence of Rebars Corrosion on Failure

    SciTech Connect

    Sudret, Bruno; Pendola, Maurice

    2002-07-01

    Natural-draught cooling towers are used in nuclear power plants as heat exchangers. These structures are submitted to environmental loads such as wind and thermal gradients that are stochastic in nature. A probabilistic framework has been developed by EDF (Electricite de France) for assessing the durability of such structures. In this paper, the corrosion of the rebars due to concrete carbonation and the corresponding weakening of the reinforced concrete sections is considered. Due to the presence of time in the definition of the limit state function associated with the loss of serviceability of the cooling tower, time-variant reliability analysis has to be used. A novel approach is proposed to take into account the random 'initiation time', which corresponds to the time necessary for the carbonation to attain the rebars. Results are given in terms of the probability of failure of the structure over its life time. (authors)

  17. Influence of Flow Rotation Within a Cooling Tower on the Aerodynamic Interaction with Crosswind Flow

    NASA Astrophysics Data System (ADS)

    Kashani, M. M. Hemmasian; Dobrego, K. V.

    2014-03-01

    Environmental crosswind changes the aerodynamic pattern inside a cooling tower, destroys uniform and axisymmetric distribution of flow at its inlet and outlet, and may degrade fill zone performance. In this paper, the effect of flow rotation in the over-shower zone of a natural draft cooling tower (NDCT) on the aerodynamic interaction with crosswind is studied numerically. The 3D geometry of an actual NDCT and three models of induced rotation velocity fields are utilized for simulation. It is demonstrated that flow rotation results in homogenization of the aerodynamic field in the over-shower zone. The inhomogeneity of the velocity field in the outlet cross section decreases linearly with rotation intensification. The effect of main stream switching under strong wind conditions is found. It is shown that even moderate flow rotation eliminates this effect.

  18. Cold weather operating guidelines and experience for natural draft cooling towers on the American Electric Power system

    SciTech Connect

    Michell, F.L.; Drew, D.H.

    1996-10-01

    American Electric Power`s more than 30 years of experience in operating natural draft cooling towers during freezing winter weather conditions is discussed in the paper. Design features incorporated into the specifications for major rebuild/repack projects for crossflow and counterflow towers to facilitate cold weather operation are also reviewed.

  19. Prevalence and Molecular Characteristics of Waterborne Pathogen Legionella in Industrial Cooling Tower Environments.

    PubMed

    Li, Lijie; Qin, Tian; Li, Yun; Zhou, Haijian; Song, Hongmei; Ren, Hongyu; Li, Liping; Li, Yongguang; Zhao, Dong

    2015-10-01

    Cooling towers are a source of Legionnaires' disease. It is important from a public health perspective to survey industrial cooling towers for the presence of Legionella. Prospective surveillance of the extent of Legionella pollution was conducted at factories in Shijiazhuang, China between March 2011 and September 2012. Overall, 35.7% of 255 industrial cooling tower water samples showed Legionella-positive, and their concentrations ranged from 100 Colony-Forming Units (CFU)/liter to 88,000 CFU/liter, with an average concentration of 9100 CFU/liter. A total of 121 isolates were obtained. All isolates were L. pneumophila, and the isolated serogroups included serogroups 1 (68 isolates, 56.2%), 6 (25, 20.7%), 5 (12, 9.9%), 8 (8, 6.6%), 3 (6, 5.0%) and 9 (2, 1.6%). All 121 isolates were analyzed by pulsed-field gel electrophoresis (PFGE) and 64 different patterns were obtained. All 121 isolates were analyzed sequence-based typing (SBT), a full 7-allele profile was obtained from 117 isolates. One hundred and seventeen isolates were divided into 49 sequence types. Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR). 92.6% (112/121) and 98.3% (119/121) isolates carried lvh and rtxA respectively and 90.9% (110/121) of tested isolates carried both genes. Our results demonstrated high prevalence and genetic polymorphism of L. pneumophila in industrial cooling tower environments in Shijiazhang, China, and the SBT and virulence gene PCR results suggested that the isolates were pathogenic. Improved control and prevention strategies are urgently needed. PMID:26473896

  20. Prevalence and Molecular Characteristics of Waterborne Pathogen Legionella in Industrial Cooling Tower Environments

    PubMed Central

    Li, Lijie; Qin, Tian; Li, Yun; Zhou, Haijian; Song, Hongmei; Ren, Hongyu; Li, Liping; Li, Yongguang; Zhao, Dong

    2015-01-01

    Cooling towers are a source of Legionnaires’ disease. It is important from a public health perspective to survey industrial cooling towers for the presence of Legionella. Prospective surveillance of the extent of Legionella pollution was conducted at factories in Shijiazhuang, China between March 2011 and September 2012. Overall, 35.7% of 255 industrial cooling tower water samples showed Legionella-positive, and their concentrations ranged from 100 Colony-Forming Units (CFU)/liter to 88,000 CFU/liter, with an average concentration of 9100 CFU/liter. A total of 121 isolates were obtained. All isolates were L. pneumophila, and the isolated serogroups included serogroups 1 (68 isolates, 56.2%), 6 (25, 20.7%), 5 (12, 9.9%), 8 (8, 6.6%), 3 (6, 5.0%) and 9 (2, 1.6%). All 121 isolates were analyzed by pulsed-field gel electrophoresis (PFGE) and 64 different patterns were obtained. All 121 isolates were analyzed sequence-based typing (SBT), a full 7-allele profile was obtained from 117 isolates. One hundred and seventeen isolates were divided into 49 sequence types. Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR). 92.6% (112/121) and 98.3% (119/121) isolates carried lvh and rtxA respectively and 90.9% (110/121) of tested isolates carried both genes. Our results demonstrated high prevalence and genetic polymorphism of L. pneumophila in industrial cooling tower environments in Shijiazhang, China, and the SBT and virulence gene PCR results suggested that the isolates were pathogenic. Improved control and prevention strategies are urgently needed. PMID:26473896

  1. Genome Sequence of Legionella massiliensis, Isolated from a Cooling Tower Water Sample.

    PubMed

    Pagnier, Isabelle; Croce, Olivier; Robert, Catherine; Raoult, Didier; La Scola, Bernard

    2014-01-01

    We present the draft genome sequence of Legionella massiliensis strain LegA(T), recovered from a cooling tower water sample, using an amoebal coculture procedure. The strain described here is composed of 4,387,007 bp, with a G+C content of 41.19%, and its genome has 3,767 protein-coding genes and 60 predicted RNA genes. PMID:25323728

  2. Extracellular polysaccharides produced by cooling water tower biofilm bacteria and their possible degradation.

    PubMed

    Ceyhan, Nur; Ozdemir, Guven

    2008-01-01

    The extracellular polymers (EPS) of biofilm bacteria that can cause heat and mass transfer problems in cooling water towers in the petrochemical industry were investigated. In addition, these microorganisms were screened for their ability to grow and degrade their own EPS and the EPS of other species. Twelve bacteria producing the most EPS were isolated from cooling water towers and characterized biochemically by classic and commercial systems. These were species of Pseudomonas, Burkholderia, Aeromonas, Pasteurella, Pantoea, Alcaligenes and Sphingomonas. EPS of these species were obtained by propan-2-ol precipitation and centrifugation from bacterial cultures in media enriched with glucose, sucrose or galactose. EPS yields were of 1.68-4.95 g l(-1). These EPS materials were characterized for total sugar and protein contents. Their total sugar content ranged from 24 to 56% (g sugar g(-1) EPS), and their total protein content ranged from 10 to 28% (g protein g(-1) EPS). The monosaccharide compositions of EPS were determined by HPLC. Generally, these compositions were enriched in galactose and glucose, with lesser amounts of mannose, rhamnose, fructose and arabinose. All bacteria were investigated in terms of EPS degradation. Eight of the bacteria were able to utilize EPS from Burkholderia cepacia, seven of the bacteria were able to utilize EPS from Pseudomonas sp. and Sphingomonas paucimobilis. The greatest viscosity reduction of B. cepacia was obtained with Pseudomonas sp. The results show that the bacteria in this study are able to degrade EPS from biofilms in cooling towers. PMID:18256966

  3. Cementitious stabilization of chromium, arsenic, and selenium in a cooling tower sludge

    SciTech Connect

    Spence, R.D.; Gilliam, T.M.; Bleier, A.

    1995-06-01

    The Federal Facility Compliance Agreement (FFCA) establishes an aggressive schedule for conducting studies and treatment method development under the treatability exclusion of RCRA for those mixed wastes for which treatment methods and capabilities have yet to be defined. One of these wastes is a radioactive cooling tower sludge. This paper presents some results of a treatability study of the stabilization of this cooling tower sludge in cementitious waste forms. The sample of the cooling tower sludge obtained for this study was found to be not characteristically hazardous in regard to arsenic, barium, chromium, lead, and selenium, despite the waste codes associated with this waste. However, the scope of this study included spiking three RCRA metals to two orders of magnitude above the initial concentration to test the limits of cementitious stabilization. Chromium and arsenic were spiked at concentrations of 200, 2,000, and 20,000 mg/kg, and selenium was spiked at 100, 1,000, and 10,000 mg/kg (concentrations based on the metal in the sludge solids). Portland cement, Class F fly ash, and slag were selected as stabilizing agents in the present study. Perlite, a fine, porous volcanic rock commonly used as a filter aid, was used as a water-sorptive agent in this study in order to control bleed water for high water contents. The highly porous perlite dust absorbs large amounts of water by capillary action and does not present the handling and processing problems exhibited by clays used for bleed water control.

  4. Reuse of refinery's tertiary-treated wastewater in cooling towers: microbiological monitoring.

    PubMed

    Dos Santos, Vera Lúcia; Veiga, Andréa Azevedo; Mendonça, Rafael Silva; Alves, Andrea Lima; Pagnin, Sérgio; Santiago, Vânia M J

    2015-02-01

    The study was planned to quantify the distribution of bacteria between bulk water and biofilm formed on different materials in an industrial scale cooling tower system of an oil refinery operating with clarified and chlorinated freshwater (CCW) or chlorinated tertiary effluent (TRW) as makeup water. The sessile and planktonic heterotrophic bacteria and Pseudomonas aeruginosa densities were significantly higher in the cooling tower supplied with clarified and chlorinated freshwater (CTCW) (p < 0.05). In the two towers, the biofilm density was higher on the surface of glass slides and stainless steel coupons than on the surface of carbon steel coupons. The average corrosion rates of carbon steel coupons (0.4-0.8 millimeters per year (mpy)) and densities of sessile (12-1.47 × 10(3) colony-forming unit (CFU) cm(-1)) and planktonic (0-2.36 × 10(3) CFU mL(-1)) microbiota remained below of the maximum values of reference used by water treatment companies as indicative of efficient microbial control. These data indicate that the strategies of the water treatment station (WTS) (free chlorine) and industrial wastewater treatment station (IWTS) followed by reverse electrodialysis system (RES) (free chlorine plus chloramine) were effective for the microbiological control of the two makeup water sources. PMID:25226836

  5. Investigation of Microbial Respirometry for Monitoring Natural Sulfide Abatement in Geothermal Cooling Tower Basins

    SciTech Connect

    Peter A. Pryfogle

    2005-09-01

    Geothermal plant operators are interested in investigating the ability of micro-organisms found in the cooling tower basin to metabolize and cycle sulfide to less toxic sulfur compounds. If the growth or activity of the organisms participating in sulfur-oxidation could be selectively enhanced, then hydrogen sulfide could be naturally abated in the cooling basin, substantially reducing the costs associated with the chemicals used for abatement. The use of respirometry has been proposed as a technique for monitoring the response of the microbial populations found in geothermal cooling towers to various conditions, including the addition of nutrients such as nitrogen and phosphorus. Respiro-metry is a manometric measurement of dissolved gases that are in equilibrium in a con-fined sample volume. Since microbes expire varying amounts of carbon dioxide or oxygen as they metabolize nutrients, this technique can be used to evaluate their activities in process streams. This report describes a series of experiments designed to determine the suitability of respirometry for tracking microbial activity for evaluating and enhancing natural abatement processes in geothermal cooling basins.

  6. Tailored draw tower fiber Bragg gratings for various sensing applications

    NASA Astrophysics Data System (ADS)

    Lindner, Eric; Mörbitz, Julia; Chojetzki, Christoph; Becker, Martin; Brückner, Sven; Schuster, Kay; Rothhardt, Manfred; Willsch, Reinhardt; Bartelt, H.

    2012-02-01

    The idea of fabricating fiber Bragg gratings during the drawing process of an optical fiber dates back almost 20 years. The application of a transverse holographic writing method on a fiber draw tower offers a promising solution for a highly effective Bragg grating production. Because of the high technology requirements it took more than 10 years to develop the method into a reliable process. The improvements in the technical development during the last five years enable today a cost efficient industrial production of draw tower grating (DTG®) arrays. In this paper we report about new possibilities of the improved process with respect to the grating type (type I gratings, type II gratings), the coating type (2ORMOCER®, metals) and the fiber diameter (125μm, 80μm and below). Furthermore, we present an example for the application of draw tower fiber Bragg gratings in sensing technologies for medical applications.

  7. Wastewater reuse in a cascade based system of a petrochemical industry for the replacement of losses in cooling towers.

    PubMed

    Hansen, Everton; Rodrigues, Marco Antônio Siqueira; Aquim, Patrice Monteiro de

    2016-10-01

    This article discusses the mapping of opportunities for the water reuse in a cascade based system in a petrochemical industry in southern Brazil. This industrial sector has a large demand for water for its operation. In the studied industry, for example, approximately 24 million cubic meters of water were collected directly from the source in 2014. The objective of this study was to evaluate the implementation of the reuse of water in cascade in a petrochemical industry, focusing on the reuse of aqueous streams to replenish losses in the cooling towers. This is an industrial scale case study with real data collected during the years 2014 and 2015. Water reuse was performed using heuristic approach based on the exploitation of knowledge acquired during the search process. The methodology of work consisted of the construction of a process map identifying the stages of production and water consumption, as well as the characterization of the aqueous streams involved in the process. For the application of the industrial water reuse as cooling water, mass balances were carried out considering the maximum concentration levels of turbidity, pH, conductivity, alkalinity, calcium hardness, chlorides, sulfates, silica, chemical oxygen demand and suspended solids as parameters turbidity, pH, conductivity, alkalinity, calcium hardness, chlorides, sulfates, silica, chemical oxygen demand and suspended solids as parameters. The adopted guideline was the fulfillment of the water quality criteria for each application in the industrial process. The study showed the feasibility for the reuse of internal streams as makeup water in cooling towers, and the implementation of the reuse presented in this paper totaled savings of 385,440 m(3)/year of water, which means a sufficient volume to supply 6350 inhabitants for a period of one year, considering the average water consumption per capita in Brazil; in addition to 201,480 m(3)/year of wastewater that would no longer be generated. PMID

  8. Minimization of corrosion using activated sodium bromide in a medium-size cooling tower

    SciTech Connect

    Nalepa, C.J.; Moore, R.M.; Golson, G.L.; Wolfe, T.W.; Puckorius, P.R.

    1996-07-01

    The cooling tower at the Albermarle Process Development Center in Baton Rouge, Louisiana, historically used chlorine as a biocide in combination with phosphorus-based corrosion/scale inhibitors. Although this regimen provided biocontrol, sludge and iron buildup was a problem in low-velocity, small cross-sectional areas of piping. A general cleanup of the system was performed in April 1995. This cleanup was followed with a switch to a two-component corrosion inhibitor/dispersant package. Alternate biocides were evaluated at this time. Activated sodium bromide was found to be particularly effective in this tower, which operates at pH {approximately}8.4. Relative to chlorine, the use of activated sodium bromide led to a decrease in general and pitting corrosion on mild steel. The reduced corrosion appears to be due to a combination of both chemical (less attack on passivated metal surfaces) and biological factors (better control of heterotrophic and sessile bacteria). These conclusions are supported by chemical analyses, corrosion meter and coupon data, dip slides, biological activity reaction tests, and visual observations of the tower sump and heat exchanger surfaces.

  9. Case study: Minimization of corrosion using activated sodium bromide in a medium-size cooling tower

    SciTech Connect

    Nalepa, C.J.; Moore, R.M.; Golson, G.L.; Wolfe, T.W.; Puckorius, P.R.

    1996-10-01

    The process loop cooling tower at the Albemarle Process Development Center in Baton Rouge, LA has historically used chlorine as the biocide together with industry accepted phosphorus-based corrosion/scale inhibitors. Although this regimen provided biocontrol, sludge and iron build-up was a recurring problem, especially in low-velocity, small cross-sectional areas of piping. A general clean-up of the system was performed in April, 1995. This clean-up was followed with a switch to a two-component corrosion inhibitor/dispersant package. It was decided to study alternate biocides as well at this time. Activated sodium bromide was found to be particularly effective in this tower, which operates at pH {approximately}8.4. Relative to chlorine, the use of activated sodium bromide led to a decrease in general and pitting corrosion on mild steel while maintaining prior performance on admiralty brass. The reduced corrosion appears to be due to a combination of both chemical (less attack on passivated metal surfaces) and biological factors (better control of heterotrophic and sessile bacteria). These conclusions are supported by chemical analyses, corrosion meter and coupon data, dip slides, BART (biological activity reaction test) tests, and visual observations of the tower sump and heat exchanger surfaces.

  10. Applications of Meteorological Tower Data at Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Altino, Karen M.; Barbre, Robert E., Jr.

    2009-01-01

    Members of the National Aeronautics and Space Administration (NASA) design and operation communities rely on meteorological information collected at Kennedy Space Center (KSC), located near Cape Canaveral, Florida, to correctly apply the ambient environment to various tasks. The Natural Environments Branch/EV44, located at Marshall Space Flight Center (MSFC) in Huntsville, Alabama, is responsible for providing its NASA customers with meteorological data using various climatological data sources including balloons, surface stations, aircraft, hindcast models, and meteorological towers. Of the many resources available within the KSC region, meteorological towers are preferred for near-surface applications because they record data at regular, frequent intervals over an extensive period of record at a single location. This paper discusses the uses of data measured at several different meteorological towers for a common period of record and how the data can be applied to various engineering decisions for the new Constellation Program Ares and Orion space vehicles.

  11. Economic and technical assessment of the desiccant wheel effect on the thermal performance of cross flow cooling towers in variable wet bulb temperature

    NASA Astrophysics Data System (ADS)

    Banooni, Salem; Chitsazan, Ali

    2014-05-01

    Performance improvements of cross flow cooling towers in variable wet bulb temperature were performed. A conventional mathematical model is used to predict desiccant wheel effect on the performance of cooling tower. It is found that by using optimum parameters of desiccant wheel, the inlet air wet bulb temperature into the cooling tower would decrease more than 6 °C and outlet water temperature would decrease more than 4 °C.

  12. Study plan for conducting a section 316(a) demonstration: K-Reactor cooling tower, Savannah River Site

    SciTech Connect

    Paller, M.H.

    1991-02-01

    The K Reactor at the Savannah River Site (SRS) began operation in 1954. The K-Reactor pumped secondary cooling water from the Savannah River and discharged directly to the Indian Grave Branch, a tributary of Pen Branch which flows to the Savannah River. During earlier operations, the temperature and discharge rates of cooling water from the K-reactor were up to approximately 70{degree}C and 400 cfs, substantially altering the thermal and flow regimes of this stream. These discharges resulted in adverse impacts to the receiving stream and wetlands along the receiving stream. As a component of a Consent Order (84-4-W as amended) with the South Carolina Department of Health and Environmental Control, the Department of Energy (DOE) evaluated the alternatives for cooling thermal effluents from K Reactor and concluded that a natural draft recirculating cooling tower should be constructed. The cooling tower will mitigate thermal and flow factors that resulted in the previous impacts to the Indian Grave/Pen Branch ecosystem. The purpose of the proposed biological monitoring program is to provide information that will support a Section 316(a) Demonstration for Indian Grave Branch and Pen Branch when K-Reactor is operated with the recirculating cooling tower. The data will be used to determine that Indian Grave Branch and Pen Branch support Balanced Indigenous Communities when K-Reactor is operated with a recirculating cooling tower. 4 refs., 1 fig. 1 tab.

  13. Molecular characterization of viable Legionella spp. in cooling tower water samples by combined use of ethidium monoazide and PCR.

    PubMed

    Inoue, Hiroaki; Fujimura, Reiko; Agata, Kunio; Ohta, Hiroyuki

    2015-01-01

    Viable Legionella spp. in environmental water samples were characterized phylogenetically by a clone library analysis combining the use of ethidium monoazide and quantitative PCR. To examine the diversity of Legionella spp., six cooling tower water samples and three bath water samples were collected and analyzed. A total of 617 clones were analyzed for their 16S rRNA gene sequences and classified into 99 operational taxonomic units (OTUs). The majority of OTUs were not clustered with currently described Legionella spp., suggesting the wide diversity of not-yet-cultured Legionella groups harbored in cooling tower water environments. PMID:25736979

  14. Molecular Characterization of Viable Legionella spp. in Cooling Tower Water Samples by Combined Use of Ethidium Monoazide and PCR

    PubMed Central

    Inoue, Hiroaki; Fujimura, Reiko; Agata, Kunio; Ohta, Hiroyuki

    2015-01-01

    Viable Legionella spp. in environmental water samples were characterized phylogenetically by a clone library analysis combining the use of ethidium monoazide and quantitative PCR. To examine the diversity of Legionella spp., six cooling tower water samples and three bath water samples were collected and analyzed. A total of 617 clones were analyzed for their 16S rRNA gene sequences and classified into 99 operational taxonomic units (OTUs). The majority of OTUs were not clustered with currently described Legionella spp., suggesting the wide diversity of not-yet-cultured Legionella groups harbored in cooling tower water environments. PMID:25736979

  15. Comparison of plate counts, Petrifilm, dipslides, and adenosine triphosphate bioluminescence for monitoring bacteria in cooling-tower waters.

    PubMed

    Mueller, Sherry A; Anderson, James E; Kim, Byung R; Ball, James C

    2009-04-01

    Effective bacterial control in cooling-tower systems requires accurate and timely methods to count bacteria. Plate-count methods are difficult to implement on-site, because they are time- and labor-intensive and require sterile techniques. Several field-applicable methods (dipslides, Petrifilm, and adenosine triphosphate [ATP] bioluminescence) were compared with the plate count for two sample matrices--phosphate-buffered saline solution containing a pure culture of Pseudomonas fluorescens and cooling-tower water containing an undefined mixed bacterial culture. For the pure culture, (1) counts determined on nutrient agar and plate-count agar (PCA) media and expressed as colony-forming units (CFU) per milliliter were equivalent to those on R2A medium (p = 1.0 and p = 1.0, respectively); (2) Petrifilm counts were not significantly different from R2A plate counts (p = 0.99); (3) the dipslide counts were up to 2 log units higher than R2A plate counts, but this discrepancy was not statistically significant (p = 0.06); and (4) a discernable correlation (r2 = 0.67) existed between ATP readings and plate counts. For cooling-tower water samples (n = 62), (1) bacterial counts using R2A medium were higher (but not significant; p = 0.63) than nutrient agar and significantly higher than tryptone-glucose yeast extract (TGE; p = 0.03) and PCA (p < 0.001); (2) Petrifilm counts were significantly lower than nutrient agar or R2A (p = 0.02 and p < 0.001, respectively), but not statistically different from TGE, PCA, and dipslides (p = 0.55, p = 0.69, and p = 0.91, respectively); (3) the dipslide method yielded bacteria counts 1 to 3 log units lower than nutrient agar and R2A (p < 0.001), but was not significantly different from Petrifilm (p = 0.91), PCA (p = 1.00) or TGE (p = 0.07); (4) the differences between dipslides and the other methods became greater with a 6-day incubation time; and (5) the correlation between ATP readings and plate counts varied from system to system, was poor

  16. Use of treated gasification wastewater in a pilot cooling tower. Phase I. Final report for the period ending January 31, 1984

    SciTech Connect

    Willson, W.G.; Hendrikson, J.G.; Mann, M.D.; Galegher, S.J.; Gallagher, J.R.; Mayer, G.G.; Thomas, W.C.; Winton, S.L.; Nelson, D.F.

    1984-05-16

    During the UNDERC cooling tower tests, data were colleced and evaluated in five major areas: characterization of cooling tower streams, process performance, biofouling, corrosion, and inorganic/organic fouling. A summary of the results and conclusions for each area is presented. Recommendations are provided for research and development programs to further define the pretreatment and operating requirements for the use of wastewater as cooling tower makeup. The results of the Phase I-Pilot Cooling Tower test have revealed several potential problems that may arise from the use of a relatively high organic content gas liquor as cooling tower makeup. Most of the problems identified are related to the presence of organics in the wastewater which promote biofouling/fouling, corrosion, and emissions from the cooling tower. The Phase II-Pilot Cooling Tower Test will address this issue by identifying the advantages of further treatment of stripped gas liquor to reduce the organic content to a lower level before use in the cooling tower. This test will parallel the Phase I test using the same system and monitoring procedures. Comparison of the results of Phase I and Phase II tests will provide an indication of how well problem areas can be avoided with additional makeup water pretreatment. 39 references, 34 tables, and 25 figures.

  17. A mechanistic approach to the development of chemical solutions for fouling of cooling tower film fills

    SciTech Connect

    Gill, J.S.; Yorke, M.A.; Donlan, R.M.; Gibbon, D.L.; McClung, B.

    1995-02-01

    Since the 1980`s reported incidents of cooling tower film fill fouling have continually increased and many utilities have sought chemical treatment solution for their fouling problems. Specialty chemical companies have been called upon to research the problems and to provide programs and products that address this pressing issue. The process of surface fouling of high efficiency film fill is a complex problem due to the multiple components involved in the fouling. An in depth understanding of the problem is necessary to determine effective treatment approaches. This study defines the mechanisms of film fill fouling by examination of microorganisms, silt particles and inorganic minerals in the fouling process. The investigation of chemical treatment approaches for the effective control of fouling based on the fouling mechanisms also are discussed.

  18. Cooling tower with concrete support structure, fiberglass panels, and a fan supported by the liquid distribution system

    SciTech Connect

    Bardo, C. J.; Clark Jr., J. L.; Dylewski, A. J.; Seawell, J. Q.

    1985-09-24

    A liquid cooling tower includes precast concrete support legs and cross beams and fiberglass reinforced polyester resin side and top panels. A liquid distribution system is supplied with liquid by a vertically extending main pipe, and a fan and fan motor are supported by the main pipe.

  19. Free-living amoebae and their associated bacteria in Austrian cooling towers: a 1-year routine screening.

    PubMed

    Scheikl, Ute; Tsao, Han-Fei; Horn, Matthias; Indra, Alexander; Walochnik, Julia

    2016-09-01

    Free-living amoebae (FLA) are widely spread in the environment and known to cause rare but often serious infections. Besides this, FLA may serve as vehicles for bacterial pathogens. In particular, Legionella pneumophila is known to replicate within FLA thereby also gaining enhanced infectivity. Cooling towers have been the source of outbreaks of Legionnaires' disease in the past and are thus usually screened for legionellae on a routine basis, not considering, however, FLA and their vehicle function. The aim of this study was to incorporate a screening system for host amoebae into a Legionella routine screening. A new real-time PCR-based screening system for various groups of FLA was established. Three cooling towers were screened every 2 weeks over the period of 1 year for FLA and Legionella spp., by culture and molecular methods in parallel. Altogether, 83.3 % of the cooling tower samples were positive for FLA, Acanthamoeba being the dominating genus. Interestingly, 69.7 % of the cooling tower samples were not suitable for the standard Legionella screening due to their high organic burden. In the remaining samples, positivity for Legionella spp. was 25 % by culture, but overall positivity was 50 % by molecular methods. Several amoebal isolates revealed intracellular bacteria. PMID:27177720

  20. Legionella species and serogroups in Malaysian water cooling towers: identification by latex agglutination and PCR-DNA sequencing of isolates.

    PubMed

    Yong, Stacey Foong Yee; Goh, Fen-Ning; Ngeow, Yun Fong

    2010-03-01

    In this study, we investigated the distribution of Legionella species in water cooling towers located in different parts of Malaysia to obtain information that may inform public health policies for the prevention of legionellosis. A total of 20 water samples were collected from 11 cooling towers located in three different states in east, west and south Malaysia. The samples were concentrated by filtration and treated with an acid buffer before plating on to BCYE agar. Legionella viable counts in these samples ranged from 100 to 2,000 CFU ml(-1); 28 isolates from the 24 samples were examined by latex agglutination as well as 16S rRNA and rpoB PCR-DNA sequencing. These isolates were identified as Legionella pneumophila serogroup 1 (35.7%), L. pneumophila serogroup 2-14 (39%), L. pneumophila non-groupable (10.7%), L. busanensis, L. gormanii, L. anisa and L. gresilensis. L. pneumophila was clearly the predominant species at all sampling sites. Repeat sampling from the same cooling tower and testing different colonies from the same water sample showed concurrent colonization by different serogroups and different species of Legionella in some of the cooling towers. PMID:20009251

  1. TESTING AND ANALYSIS OF A WET-DRY CROSSFLOW COOLING TOWER, VOLUME I: TEST PROGRAM AND RESULTS

    EPA Science Inventory

    The report discusses the test program and performance analysis of a single-cell mechanical-draft wet/dry cooling tower in Cliffside, NC. Objectives of the program were to obtain performance data and results on mass transfer, heat transfer, fluid flow, plume formation, and acousti...

  2. Hydraulic design of a low-specific speed Francis runner for a hydraulic cooling tower

    NASA Astrophysics Data System (ADS)

    Ruan, H.; Luo, X. Q.; Liao, W. L.; Zhao, Y. P.

    2012-11-01

    The air blower in a cooling tower is normally driven by an electromotor, and the electric energy consumed by the electromotor is tremendous. The remaining energy at the outlet of the cooling cycle is considerable. This energy can be utilized to drive a hydraulic turbine and consequently to rotate the air blower. The purpose of this project is to recycle energy, lower energy consumption and reduce pollutant discharge. Firstly, a two-order polynomial is proposed to describe the blade setting angle distribution law along the meridional streamline in the streamline equation. The runner is designed by the point-to-point integration method with a specific blade setting angle distribution. Three different ultra-low-specificspeed Francis runners with different wrap angles are obtained in this method. Secondly, based on CFD numerical simulations, the effects of blade setting angle distribution on pressure coefficient distribution and relative efficiency have been analyzed. Finally, blade angles of inlet and outlet and control coefficients of blade setting angle distribution law are optimal variables, efficiency and minimum pressure are objective functions, adopting NSGA-II algorithm, a multi-objective optimization for ultra-low-specific speed Francis runner is carried out. The obtained results show that the optimal runner has higher efficiency and better cavitation performance.

  3. Legionnaires' Disease Outbreak at a Long-Term Care Facility Caused by a Cooling Tower Using an Automated Disinfection System--Ohio, 2013.

    PubMed

    Quinn, Celia; Demirjian, Alicia; Watkins, Louise Francois; Tomczyk, Sara; Lucas, Claressa; Brown, Ellen; Kozak-Muiznieks, Natalia; Benitez, Alvaro; Garrison, Laurel E; Kunz, Jasen; Brewer, Scott; Eitniear, Samantha; DiOrio, Mary

    2015-12-01

    On July 9, 2013, an outbreak of Legionnaires' disease (LD) was identified at Long-Term Care Facility A in central Ohio. This article describes the investigation of the outbreak and identification of the outbreak source, a cooling tower using an automated biocide delivery system. In total, 39 outbreak LD cases were identified; among these, six patients died. Water samples from a cooling tower were positive for Legionella pneumophila serogroup 1, reactive to monoclonal antibody 2, with matching sequence type to a patient isolate. An electronic control system turned off cooling tower pumps during low-demand periods, preventing delivery of disinfectant by a timed-release system, and leading to amplification of Legionella in the cooling tower. Guidelines for tower maintenance should address optimal disinfection when using automated systems. PMID:26738313

  4. Direct injection GC method for measuring light hydrocarbon emissions from cooling-tower water.

    PubMed

    Lee, Max M; Logan, Tim D; Sun, Kefu; Hurley, N Spencer; Swatloski, Robert A; Gluck, Steve J

    2003-12-15

    A Direct Injection GC method for quantifying low levels of light hydrocarbons (C6 and below) in cooling water has been developed. It is intended to overcome the limitations of the currently available technology. The principle of this method is to use a stripper column in a GC to strip waterfrom the hydrocarbons prior to entering the separation column. No sample preparation is required since the water sample is introduced directly into the GC. Method validation indicates that the Direct Injection GC method offers approximately 15 min analysis time with excellent precision and recovery. The calibration studies with ethylene and propylene show that both liquid and gas standards are suitable for routine calibration and calibration verification. The sampling method using zero headspace traditional VOA (Volatile Organic Analysis) vials and a sample chiller has also been validated. It is apparent that the sampling method is sufficient to minimize the potential for losses of light hydrocarbons, and samples can be held at 4 degrees C for up to 7 days with more than 93% recovery. The Direct Injection GC method also offers <1 ppb (w/v) level method detection limits for ethylene, propylene, and benzene. It is superior to the existing El Paso stripper method. In addition to lower detection limits for ethylene and propylene, the Direct Injection GC method quantifies individual light hydrocarbons in cooling water, provides better recoveries, and requires less maintenance and setup costs. Since the instrumentation and supplies are readily available, this technique could easily be established as a standard or alternative method for routine emission monitoring and leak detection of light hydrocarbons in cooling-tower water. PMID:14717185

  5. AUTOMATED DEAD-END ULTRAFILTRATION FOR ENHANCED SURVEILLANCE OF LEGIONELLA 2 PNEUMOPHILA AND LEGIONELLA SPP. IN COOLING TOWER WATERS

    SciTech Connect

    Brigmon, R.; Leskinen, S.; Kearns, E.; Jones, W.; Miller, R.; Betivas, C.; Kingsley, M.; Lim, D.

    2011-10-10

    Detection of Legionella pneumophila in cooling towers and domestic hot water systems involves concentration by centrifugation or membrane filtration prior to inoculation onto growth media or analysis using techniques such as PCR or immunoassays. The Portable Multi-use Automated Concentration System (PMACS) was designed for concentrating microorganisms from large volumes of water in the field and was assessed for enhancing surveillance of L. pneumophila at the Savannah River Site, SC. PMACS samples (100 L; n = 28) were collected from six towers between August 2010 and April 2011 with grab samples (500 ml; n = 56) being collected before and after each PMACS sample. All samples were analyzed for the presence of L. pneumophila by direct fluorescence immunoassay (DFA) using FITC-labeled monoclonal antibodies targeting serogroups 1, 2, 4 and 6. QPCR was utilized for detection of Legionella spp. in the same samples. Counts of L. pneumophila from DFA and of Legionella spp. from qPCR were normalized to cells/L tower water. Concentrations were similar between grab and PMACS samples collected throughout the study by DFA analysis (P = 0.4461; repeated measures ANOVA). The same trend was observed with qPCR. However, PMACS concentration proved advantageous over membrane filtration by providing larger volume, more representative samples of the cooling tower environment, which led to reduced variability among sampling events and increasing the probability of detection of low level targets. These data highlight the utility of the PMACS for enhanced surveillance of L. pneumophila by providing improved sampling of the cooling tower environment.

  6. Detection of Legionella pneumophila by PCR-ELISA method in industrial cooling tower water.

    PubMed

    Soheili, Majid; Nejadmoghaddam, Mohammad Reza; Babashamsi, Mohammad; Ghasemi, Jamileh; Jeddi Tehrani, Mahmood

    2007-11-15

    Water supply and Cooling Tower Water (CTW) are among the most common sources of Legionella pneumophila (LP) contamination. A nonradio active method is described to detect LP in industrial CTW samples. DNA was purified and amplified by nested -PCR with amplimers specific for the 16s rRNA gene of LP. The 5' end biotinylated oligomer probe was immobilized on sterptavidin B coated microtiter plates. The nested-PCR product was labeled with digoxigenin and then hybridized with 5'-biotinylated probes. The amplification products were detected by using proxidase-labled anti dioxygenin antibody in a colorimetric reaction. The assay detected LP present in 1 L of 5 CTW samples examined. All of the samples were Legionella positive in both culture and PCR-ELISA methods. The PCR-ELISA assay appears to exhibit high specificity and is a more rapid technique in comparison with bacterial culture method. Thus could prove suitable for use in the routine examination of industrial CTW contamination. PMID:19090273

  7. Treatment of cooling tower blowdown water containing silica, calcium and magnesium by electrocoagulation.

    PubMed

    Liao, Z; Gu, Z; Schulz, M C; Davis, J R; Baygents, J C; Farrell, J

    2009-01-01

    This research investigated the effectiveness of electrocoagulation using iron and aluminium electrodes for treating cooling tower blowdown (CTB) waters containing dissolved silica (Si(OH)(4)), Ca(2 + ) and Mg(2 + ). The removal of each target species was measured as a function of the coagulant dose in simulated CTB waters with initial pH values of 5, 7, and 9. Experiments were also performed to investigate the effect of antiscaling compounds and coagulation aids on hardness ion removal. Both iron and aluminum electrodes were effective at removing dissolved silica. For coagulant doses < or =3 mM, silica removal was a linear function of the coagulant dose, with 0.4 to 0.5 moles of silica removed per mole of iron or aluminium. Iron electrodes were only 30% as effective at removing Ca(2 + ) and Mg(2 + ) as compared to silica. There was no measurable removal of hardness ions by aluminium electrodes in the absence of organic additives. Phosphonate based antiscaling compounds were uniformly effective at increasing the removal of Ca(2 + ) and Mg(2 + ) by both iron and aluminium electrodes. Cationic and amphoteric polymers used as coagulation aids were also effective at increasing hardness ion removal. PMID:19901466

  8. Improved facility and sensitivity in the use of guinea pigs for the isolation of Legionella pneumophila from cooling tower water

    SciTech Connect

    Leinbach, E.D.; Winkler, H.H.; Wood, D.O.; Coggin, J.H. Jr.

    1983-03-01

    The established criteria for the determination of the optimum time for the sacrifice of guinea pigs inoculated with samples of cooling tower water were found to be inadequate for the detection of low levels of Legionella pneumophila. By ignoring the requirement for fever and by sequentially sacrificing the infected guinea pigs on days 3 through 5 postinoculation, we simplified the procedure, and the sensitivity of detection was improved a great deal.

  9. Mutagenic activity associated with cooling tower waters treated with a biocide containing 5-chloro-2-methyl-4-isothiazolin-3-one

    SciTech Connect

    Woodall, G.M.; Pancorbo, O.C.; Blevins, R.D.; Ferslew, K.E.

    1987-08-01

    With the Ames Salmonella-mammalian microsome test, significant mutagenic activity was detected in cooling tower water shortly (same day) after treatment with a biocide (CL2150) containing 5-chloro-2-methyl-4-isothiazolin-3-one(5-chloro-IT). Dose-related mutagenic responses with TA97 (-S9) and TA100 (-S9) were produced with the acid fraction (extracted at pH <2 with methylene chloride) of this cooling water sample (specific mutagenic activities of 281,000 and 188,000 net revertants/L equiv of water, respectively). This mutagenic activity detected in cooling water sampled in mid-summer did not persist beyond the first day of CL2150 treatment. The mutagenic activity displayed by the cooling waters with TA97 (-S9) exceeded that associated with the extractable 5-chloro-IT concentration (determined by capillary gas chromatography-mass spectrometry). 24 references, 6 figures, 3 tables.

  10. Technology to Facilitate the Use of Impaired Waters in Cooling Towers

    SciTech Connect

    Colborn, Robert

    2012-04-30

    The project goal was to develop an effective silica removal technology and couple that with existing electro-dialysis reversal (EDR) technology to achieve a cost effective treatment for impaired waters to allow for their use in the cooling towers of coal fired power plants. A quantitative target of the program was a 50% reduction in the fresh water withdrawal at a levelized cost of water of $3.90/Kgal. Over the course of the program, a new molybdenum-modified alumina was developed that significantly outperforms existing alumina materials in silica removal both kinetically and thermodynamically. The Langmuir capacity is 0.11g silica/g adsorbent. Moreover, a low cost recycle/regeneration process was discovered to allow for multiple recycles with minimal loss in activity. On the lab scale, five runs were carried out with no drop in performance between the second and fifth run in ability to absorb the silica from water. The Mo-modified alumina was successfully prepared on a multiple kilogram scale and a bench scale model column was used to remove 100 ppm of silica from 400 liters of simulated impaired water. Significant water savings would result from such a process and the regeneration process could be further optimized to reduce water requirements. Current barriers to implementation are the base cost of the adsorbent material and the fine powder form that would lead to back pressure on a large column. If mesoporous materials become more commonly used in other areas and the price drops from volume and process improvements, then our material would also lower in price because the amount of molybdenum needed is low and no additional processing is required. There may well be engineering solutions to the fine powder issue; in a simple concept experiment, we were able to pelletize our material with Boehmite, but lost performance due to a dramatic decrease in surface area.

  11. Legionella detection and subgrouping in water air-conditioning cooling tower systems in Kuwait.

    PubMed

    Al-Matawah, Qadreyah; Al-Zenki, Sameer; Al-Azmi, Ahmad; Al-Waalan, Tahani; Al-Salameen, Fadila; Hejji, Ahmad Ben

    2015-07-01

    The main aim of the study was to test for the presence of Legionnaires' disease-causing microorganisms in air-conditioned buildings in Kuwait using molecular technologies. For this purpose, 547 samples were collected from 38 cooling towers for the analysis of Legionella pneumophila. These samples included those from water (n = 178), air (n = 231), and swabs (n = 138). Out of the 547 samples, 226 (41%) samples were presumptive positive for L. pneumophila, with L. pneumophila viable counts in the positive water samples ranging from 1 to 88 CFU/ml. Of the Legionella culture-positive samples, 204 isolates were examined by latex agglutination. These isolates were predominately identified as L. pneumophila serogroup (sg) 2-14. Using the Dresden panel of monoclonal antibodies, 74 representatives isolates were further serogrouped. Results showed that 51% of the isolates belonged to serogroup 7 followed by 1 (18%) and 3 (18%). Serogroups 4 (4%) and 10 (7%) were isolated at a lower frequency, and two isolates could not be assigned to a serogroup. These results indicate the wide prevalence of L. pneumophila serogroup 7 as the predominant serogroup at the selected sampling sites. Furthermore, the 74 L. pneumophila (sg1 = 13; sg3 = 13; sg4 = 3; sg7 = 38; sg10 = 5; sgX = 2) isolates were genotyped using the seven gene protocol sequence-based typing (SBT) scheme developed by the European Working Group for Legionella Infections (EWGLI). The results show that Legionella isolates were discriminated into nine distinct sequence typing (ST) profiles, five of which were new to the SBT database of EWGLI. Additionally, all of the ST1 serogroup 1 isolates were of the OLDA/Oxford subgroup. These baseline data will form the basis for the development of a Legionella environmental surveillance program and used for future epidemiological investigations. PMID:25701245

  12. Analysis of construction conditions affecting the structural response of the cooling tower at Willow Island, West Virginia

    SciTech Connect

    Lew, H.S.; Fattal, S.G.

    1980-07-01

    The initial investigation of the Willow Island cooling tower collapse (NBSIR 78-1578) established that the most probable cause of the collapse was the imposition of construction loads on the tower before the concrete had gained adequate strength. The analysis presented herein responds to questions outside the scope of that investigation which considered only actual conditions existing at the time of the collapse. The present investigation shows that failure would initiate in lift 28 if the concrete strength in that lift is 100 psi (6.9 MPa) or less, and to maintain a safety factor of 2.0, the concrete strength in that lift should be 4000 psi (27.6 MPa). This study also reveals that even if an additional bolt had been introduced between each exterior jumpform beam and the tower, the stresses would not have been relieved enough to prevent failure of lift 28. Finally, it is shown, that if the ground anchor point of the static line had been kept at the location occupied just prior to its last move to a location near the center of the tower, the stresses in the shell due to construction loads would have been relieved to the extent that failure of lift 28 would probably not have occurred.

  13. Legionnaires’ disease from a cooling tower in a community outbreak in Lidköping, Sweden- epidemiological, environmental and microbiological investigation supported by meteorological modelling

    PubMed Central

    2012-01-01

    Background An outbreak of Legionnaires’ Disease took place in the Swedish town Lidköping on Lake Vänern in August 2004 and the number of pneumonia cases at the local hospital increased markedly. As soon as the first patients were diagnosed, health care providers were informed and an outbreak investigation was launched. Methods Classical epidemiological investigation, diagnostic tests, environmental analyses, epidemiological typing and meteorological methods. Results Thirty-two cases were found. The median age was 62 years (range 36 – 88) and 22 (69%) were males. No common indoor exposure was found. Legionella pneumophila serogroup 1 was found at two industries, each with two cooling towers. In one cooling tower exceptionally high concentrations, 1.2 × 109 cfu/L, were found. Smaller amounts were also found in the other tower of the first industry and in one tower of the second plant. Sero- and genotyping of isolated L. pneumophila serogroup 1 from three patients and epidemiologically suspected environmental strains supported the cooling tower with the high concentration as the source. In all, two L. pneumophila strains were isolated from three culture confirmed cases and both these strains were detected in the cooling tower, but one strain in another cooling tower as well. Meteorological modelling demonstrated probable spread from the most suspected cooling tower towards the town centre and the precise location of four cases that were stray visitors to Lidköping. Conclusions Classical epidemiological, environmental and microbiological investigation of an LD outbreak can be supported by meteorological modelling methods. The broad competence and cooperation capabilities in the investigation team from different authorities were of paramount importance in stopping this outbreak. PMID:23171054

  14. The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor.

    PubMed

    Minnoş, Bihter; Ilhan-Sungur, Esra; Çotuk, Ayşın; Güngör, Nihal Doğruöz; Cansever, Nurhan

    2013-01-01

    The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor was investigated over a 10-month period in a hotel. Planktonic and sessile numbers of sulphate reducing bacteria (SRB) and heterotrophic bacteria were monitored. The corrosion rate was determined by the weight loss method. The corrosion products were analyzed by energy dispersive X-ray spectroscopy and X-ray diffraction. A mineralized, heterogeneous biofilm was observed on the coupons. Although a biocide and a corrosion inhibitor were regularly added to the cooling water, the results showed that microorganisms, such as SRB in the mixed species biofilm, caused corrosion of galvanized steel. It was observed that Zn layers on the test coupons were completely depleted after 3 months. The Fe concentrations in the biofilm showed significant correlations with the weight loss and carbohydrate concentration (respectively, p < 0.01 and p < 0.01). PMID:23439037

  15. Acidity of vapor plume from cooling tower mixed with flue gases emitted from coal-fired power plant.

    PubMed

    Hlawiczka, Stanislaw; Korszun, Katarzyna; Fudala, Janina

    2016-06-01

    Acidity of products resulting from the reaction of flue gas components emitted from a coal-fired power plant with water contained in a vapor plume from a wet cooling tower was analyzed in a close vicinity of a power plant (710 m from the stack and 315 m from the cooling tower). Samples of this mixture were collected using a precipitation funnel where components of the mixed plumes were discharged from the atmosphere with the rainfall. To identify situations when the precipitation occurred at the same time as the wind directed the mixed vapor and flue gas plumes above the precipitation funnel, an ultrasound anemometer designed for 3D measurements of the wind field located near the funnel was used. Precipitation samples of extremely high acidity were identified - about 5% of samples collected during 12 months showed the acidity below pH=3 and the lowest recorded pH was 1.4. During the measurement period the value of pH characterizing the background acidity of the precipitation was about 6. The main outcome of this study was to demonstrate a very high, and so far completely underestimated, potential of occurrence of episodes of extremely acid depositions in the immediate vicinity of a coal-fired power plant. PMID:26950639

  16. Application of uncertainty analysis to cooling tower thermal performance tests

    SciTech Connect

    Yost, J.G.; Wheeler, D.E.

    1986-01-01

    The purpose of this paper is to provide an overview of uncertainty analyses. The following topics are addressed: l. A review and summary of the basic constituents of an uncertainty analysis with definitions and discussion of basic terms; 2. A discussion of the benefits and uses of uncertainty analysis; and 3. Example uncertainty analyses with emphasis on the problems, limitations, and site-specific complications.

  17. Mathematical Model of Two Phase Flow in Natural Draft Wet-Cooling Tower Including Flue Gas Injection

    NASA Astrophysics Data System (ADS)

    Hyhlík, Tomáš

    2016-03-01

    The previously developed model of natural draft wet-cooling tower flow, heat and mass transfer is extended to be able to take into account the flow of supersaturated moist air. The two phase flow model is based on void fraction of gas phase which is included in the governing equations. Homogeneous equilibrium model, where the two phases are well mixed and have the same velocity, is used. The effect of flue gas injection is included into the developed mathematical model by using source terms in governing equations and by using momentum flux coefficient and kinetic energy flux coefficient. Heat and mass transfer in the fill zone is described by the system of ordinary differential equations, where the mass transfer is represented by measured fill Merkel number and heat transfer is calculated using prescribed Lewis factor.

  18. Quasi One-Dimensional Model of Natural Draft Wet-Cooling Tower Flow, Heat and Mass Transfer

    NASA Astrophysics Data System (ADS)

    Hyhlík, Tomáš

    2015-05-01

    The article deals with the development of CFD (Computational Fluid Dynamics) model of natural draft wet-cooling tower flow, heat and mass transfer. The moist air flow is described by the system of conservation laws along with additional equations. Moist air is assumed to be homogeneous mixture of dry air and water vapour. Liquid phase in the fill zone is described by the system of ordinary differential equations. Boundary value problem for the system of conservation laws is discretized in space using Kurganov-Tadmor central scheme and in time using strong stability preserving Runge-Kutta scheme. Initial value problems in the fill zone is solved by using standard fourth order Runge-Kutta scheme. The interaction between liquid water and moist air is done by source terms in governing equations.

  19. Testing and analysis of a wet-dry crossflow cooling tower. Volume II. Appendices. Final report, July 1977-May 1981

    SciTech Connect

    Ayers, D.L.; Hogan, M.R.; Hribar, A.E.; Lucheta, R.A.

    1981-07-01

    The report discusses the test program and performance analysis of a single-cell mechanical-draft wet/dry cooling tower in Cliffside, NC. Objectives of the program were to obtain performance data and results on mass transfer, heat transfer, fluid flow, plume formation, and acoustic characteristics for comparison with models/theories. Correlations are presented for the wet-fill mass transfer coefficient, wet-fill water loss, Colburn j-factor for the finned tubes, and fan efficiency in terms of one or more of the following: water loading in the tubes, air loading over the fins, log mean humidity difference, outlet water temperature, Reynolds number, and airflow rate. Acoustic data were fitted to a series of curves for each of the eight octave bands. Attempts to model plume data failed. The report also describes the test facility, test procedures, instrumentation, data acquisition, and data reduction.

  20. Distribution of Sequence-Based Types of Legionella pneumophila Serogroup 1 Strains Isolated from Cooling Towers, Hot Springs, and Potable Water Systems in China

    PubMed Central

    Zhou, Haijian; Ren, Hongyu; Guan, Hong; Li, Machao; Zhu, Bingqing

    2014-01-01

    Legionella pneumophila serogroup 1 causes Legionnaires' disease. Water systems contaminated with Legionella are the implicated sources of Legionnaires' disease. This study analyzed L. pneumophila serogroup 1 strains in China using sequence-based typing. Strains were isolated from cooling towers (n = 96), hot springs (n = 42), and potable water systems (n = 26). Isolates from cooling towers, hot springs, and potable water systems were divided into 25 sequence types (STs; index of discrimination [IOD], 0.711), 19 STs (IOD, 0.934), and 3 STs (IOD, 0.151), respectively. The genetic variation among the potable water isolates was lower than that among cooling tower and hot spring isolates. ST1 was the predominant type, accounting for 49.4% of analyzed strains (n = 81), followed by ST154. With the exception of two strains, all potable water isolates (92.3%) belonged to ST1. In contrast, 53.1% (51/96) and only 14.3% (6/42) of cooling tower and hot spring, respectively, isolates belonged to ST1. There were differences in the distributions of clone groups among the water sources. The comparisons among L. pneumophila strains isolated in China, Japan, and South Korea revealed that similar clones (ST1 complex and ST154 complex) exist in these countries. In conclusion, in China, STs had several unique allelic profiles, and ST1 was the most prevalent sequence type of environmental L. pneumophila serogroup 1 isolates, similar to its prevalence in Japan and South Korea. PMID:24463975

  1. Distribution of sequence-based types of legionella pneumophila serogroup 1 strains isolated from cooling towers, hot springs, and potable water systems in China.

    PubMed

    Qin, Tian; Zhou, Haijian; Ren, Hongyu; Guan, Hong; Li, Machao; Zhu, Bingqing; Shao, Zhujun

    2014-04-01

    Legionella pneumophila serogroup 1 causes Legionnaires' disease. Water systems contaminated with Legionella are the implicated sources of Legionnaires' disease. This study analyzed L. pneumophila serogroup 1 strains in China using sequence-based typing. Strains were isolated from cooling towers (n = 96), hot springs (n = 42), and potable water systems (n = 26). Isolates from cooling towers, hot springs, and potable water systems were divided into 25 sequence types (STs; index of discrimination [IOD], 0.711), 19 STs (IOD, 0.934), and 3 STs (IOD, 0.151), respectively. The genetic variation among the potable water isolates was lower than that among cooling tower and hot spring isolates. ST1 was the predominant type, accounting for 49.4% of analyzed strains (n = 81), followed by ST154. With the exception of two strains, all potable water isolates (92.3%) belonged to ST1. In contrast, 53.1% (51/96) and only 14.3% (6/42) of cooling tower and hot spring, respectively, isolates belonged to ST1. There were differences in the distributions of clone groups among the water sources. The comparisons among L. pneumophila strains isolated in China, Japan, and South Korea revealed that similar clones (ST1 complex and ST154 complex) exist in these countries. In conclusion, in China, STs had several unique allelic profiles, and ST1 was the most prevalent sequence type of environmental L. pneumophila serogroup 1 isolates, similar to its prevalence in Japan and South Korea. PMID:24463975

  2. NASA Marshall Space Flight Center Improves Cooling System Performance: Best Management Practice Case Study #10: Cooling Towers (Fact Sheet)

    SciTech Connect

    Not Available

    2011-02-01

    National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) has a longstanding sustainability program that revolves around energy and water efficiency as well as environmental protection. MSFC identified a problematic cooling loop with six separate compressor heat exchangers and a history of poor efficiency. The facility engineering team at MSFC partnered with Flozone Services, Incorporated to implement a comprehensive water treatment platform to improve the overall efficiency of the system.

  3. 40 CFR 63.400 - Applicability.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Hazardous Air Pollutants for Industrial Process Cooling Towers § 63.400 Applicability. (a) The provisions of this subpart apply to all new and existing industrial process cooling towers that are operated...

  4. 40 CFR 63.400 - Applicability.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Hazardous Air Pollutants for Industrial Process Cooling Towers § 63.400 Applicability. (a) The provisions of this subpart apply to all new and existing industrial process cooling towers that are operated...

  5. 40 CFR 63.400 - Applicability.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Hazardous Air Pollutants for Industrial Process Cooling Towers § 63.400 Applicability. (a) The provisions of this subpart apply to all new and existing industrial process cooling towers that are operated...

  6. 40 CFR 63.400 - Applicability.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Hazardous Air Pollutants for Industrial Process Cooling Towers § 63.400 Applicability. (a) The provisions of this subpart apply to all new and existing industrial process cooling towers that are operated...

  7. Legionella pneumophila in cooling water systems. Report of a survey of cooling towers in London and a pilot trial of selected biocides.

    PubMed Central

    Kurtz, J. B.; Bartlett, C. L.; Newton, U. A.; White, R. A.; Jones, N. L.

    1982-01-01

    Fourteen recirculating cooling water systems were surveyed during the summer, 1981, to see what factors might influence the prevalence of Legionella pneumophila. The effect on the organism of three anti-microbials was studied, each in two systems, by intermittent treatment at two week intervals. L. pneumophila was isolated from six of the 14 cooling systems at the beginning of the trial but by the end was present in ten. An association was found between the presence of the organism and the concentration of dissolved solids, and chlorides and the pH. There also appeared to be associations with exclusion of light and higher water temperatures. Repeated tests on eight untreated systems showed that two were consistently infected, three became and remained infected, one was infected on a single occasion and two were never infected with L. pneumophila. Treatment of a contaminated system, either with a 10 p.p.m mixture of a quaternary ammonium compound and tributyltinoxide or slow release chlorine briquettes (maximum recorded free chlorine level 1.2 p.p.m.), did not eliminated legionellae. Treatment of two infected towers with a chlorinated phenol (100 p.p.m.) eliminated legionellae for at least three days, but after 14 days the organism was again found. PMID:7086112

  8. Horizontal cooling towers: riverine ecosystem services and the fate of thermoelectric heat in the contemporary Northeast US

    NASA Astrophysics Data System (ADS)

    Stewart, Robert J.; Wollheim, Wilfred M.; Miara, Ariel; Vörösmarty, Charles J.; Fekete, Balazs; Lammers, Richard B.; Rosenzweig, Bernice

    2013-06-01

    The electricity sector is dependent on rivers to provide ecosystem services that help regulate excess heat, either through provision of water for evaporative cooling or by conveying, diluting and attenuating waste heat inputs. Reliance on these ecosystem services alters flow and temperature regimes, which impact fish habitat and other aquatic ecosystem services. We demonstrate the contemporary (2000-2010) dependence of the electricity sector on riverine ecosystem services and associated aquatic impacts in the Northeast US, a region with a high density of thermoelectric power plants. We quantify these dynamics using a spatially distributed hydrology and water temperature model (the framework for aquatic modeling in the Earth system), coupled with the thermoelectric power and thermal pollution model. We find that 28.4% of thermoelectric heat production is transferred to rivers, whereas 25.9% is directed to vertical cooling towers. Regionally, only 11.3% of heat transferred to rivers is dissipated to the atmosphere and the rest is delivered to coasts, in part due to the distribution of power plants within the river system. Impacts to the flow regime are minimal, while impacts to the thermal regime include increased river lengths of unsuitable habitats for fish with maximum thermal tolerances of 24.0, 29.0, and 34.0 ° C in segments downstream of plants by 0.6%, 9.8%, and 53.9%, respectively. Our analysis highlights the interactions among electricity production, cooling technologies, aquatic impacts, and ecosystem services, and can be used to assess the full costs and tradeoffs of electricity production at regional scales.

  9. Evaporation Tower With Prill Nozzles

    NASA Technical Reports Server (NTRS)

    Du Fresne, E. R.

    1984-01-01

    Tower more efficient than conventional evaporation equipment. Liquids such as milk and fruit juice concentrated by passing them through tiny nozzle to form droplets, then allowing droplets to fall through evacuated tower with cooled walls.

  10. A study of a desuperheater heat recovery system complete with a reversibly used water cooling tower (RUWCT) for hot water supply

    NASA Astrophysics Data System (ADS)

    Tan, Kunxiong

    Recovering heat rejected from the condenser in a refrigeration system to generate service hot water for buildings is commonly seen in both tropics and subtropics. This study included a critical literature review on heat recovery from air-conditioning/refrigeration systems, with particular emphasis on the direct condenser heat recovery and its related mathematical simulation models. The review identified many applications of desuperheaters to small-scaled residential air-conditioning or heat pump units. The heat and mass transfer characteristics of a RUWCT have been studied in detail, which is based on the theory of direct contact heat and mass transfer between moist air and water. The thesis reports on the differences in the heat and mass transfer process that takes place in a RUWCT, a standard water cooling tower and a spray room. A corrective factor that accounts for the change of chilled water mass flow rate is incorporated into the theoretical analysis of a RUWCT. The algorithms developed from the theoretical analysis are capable of predicting the heat exchange capacity of a RUWCT at any operating conditions. This theoretical analysis is the first of its kind. Extensive field experimental work on the heat and mass transfer characteristics of a RUWCT has been carried out in a hotel building in Haikou, Hainan province of China, where the RUWCT is installed. Results from the experimental work indicate that the theoretical analysis can represent the heat and mass transfer characteristics in a RUWCT with an acceptable accuracy. A numerical analysis for a RUWCT is undertaken to determine both air and water states at intermediate horizontal sections along the tower height. Field experimental data confirm that the predicted air and water conditions at the tower inlet and outlet are of acceptable accuracy. A steady-state mathematical model is developed to simulate the operational performance of a water chiller plant complete with a desuperheater heat recovery system and

  11. Heat-transfer characteristics of a dry and wet/dry advanced condenser for cooling towers

    NASA Astrophysics Data System (ADS)

    Fricke, H. D.; McIlroy, K.; Webster, D. J.

    1982-06-01

    An experimental evaluation of two types of advanced, air cooled ammonia condensers for a phase change dry/wet cooling system for electric power plants is described. Condensers of similar design, but much bigger, are being tested in a 15 MWe demonstration plant. These condensers, featuring different air side augmentation, were tested in an ammonia phase change pilot plant (0.3 MWe). The first unit consisted of the integral shaved fin extruded aluminum tubing designed for dry operation. Heat transfer and air side pressure loss characteristics were measured under varying air face velocities (600 to 1000 FPM) and initial temperature differences, ITD (20 to 60 F). Overall heat transfer coefficients (based on air side surface), U, ranged between 7.0 to 8.6 Btu/hr sq ft. F. The second configuration constituted the Hoterv aluminum plate fin/tube assembly of which two different sizes (5 sq ft and 58 sq ft frontal area) were performance tested; in both dry and wet modes at 200 to 800 FPM air face velocities, ITD's of 10 to 60 F and at water deluge rates up to 3.0 gpm/ft. of core width.

  12. Corrosion-induced Whole Effluent Toxicity from a cooling tower: A toxicity reduction evaluation case study

    SciTech Connect

    Fort, D.J.; Stover, E.L.; Talley, J.M.; Copenhaver, M.B.

    1996-11-01

    As the result of Whole Effluent Toxicity (WET) test failures with Daphnia pulex, the US Environmental Protection Agency (EPA) required an industrial facility discharging approximately 5 million gallons per day (MGD) of recirculating cooling water obtained from a large freshwater river to conduct a Toxicity Reduction Evaluation (TRE) program. Under the terms of the National Pollutant Discharge Elimination System (NPDES) permit, the facility was required to conduct 48-hour acute toxicity tests with D. pulex and Pimephales promelas (fathead minnow). Although effluent toxicity to D. pulex was consistently observed, no toxicity was induced to the fathead minnow during the TRE program. The situation was further complicated by the fact that the recirculating cooling water was discharged back into the same river. The objectives of the TRE program were to investigate the causes of toxicity, locate potential sources of the suspected toxicant(s), and identify practicable toxicity reduction methodologies to be used. The TRE program approach and results from the associated studies are presented in this report, including a successful remedy for the WET problem.

  13. Corrosion control when using secondary treated municipal wastewater as alternative makeup water for cooling tower systems.

    PubMed

    Hsieh, Ming-Kai; Li, Heng; Chien, Shih-Hsiang; Monnell, Jason D; Chowdhury, Indranil; Dzombak, David A; Vidic, Radisav D

    2010-12-01

    Secondary treated municipal wastewater is a promising alternative to fresh water as power plant cooling water system makeup water, especially in arid regions. Laboratory and field testing was conducted in this study to evaluate the corrosiveness of secondary treated municipal wastewater for various metals and metal alloys in cooling systems. Different corrosion control strategies were evaluated based on varied chemical treatment. Orthophosphate, which is abundant in secondary treated municipal wastewater, contributed to more than 80% precipitative removal of phosphorous-based corrosion inhibitors. Tolyltriazole worked effectively to reduce corrosion of copper (greater than 95% inhibition effectiveness). The corrosion rate of mild steel in the presence of free chlorine 1 mg/L (as Cl2) was approximately 50% higher than in the presence of monochloramine 1 mg/L (as Cl2), indicating that monochloramine is a less corrosive biocide than free chlorine. The scaling layers observed on the metal alloys contributed to corrosion inhibition, which could be seen by comparing the mild steel 21-day average corrosion rate with the last 5-day average corrosion rate, the latter being approximately 50% lower than the former. PMID:21214028

  14. Microgravity Spray Cooling Research for High Powered Laser Applications

    NASA Technical Reports Server (NTRS)

    Zivich, Chad P.

    2004-01-01

    An extremely powerful laser is being developed at Goddard Space Flight Center for use on a satellite. This laser has several potential applications. One application is to use it for upper atmosphere weather research. In this case, the laser would reflect off aerosols in the upper atmosphere and bounce back to the satellite, where the aerosol velocities could be calculated and thus the upper atmosphere weather patterns could be monitored. A second application would be for the US. Air Force, which wants to use the laser strategically as a weapon for satellite defense. The Air Force fears that in the coming years as more and more nations gain limited space capabilities that American satellites may become targets, and the laser could protect the satellites. Regardless of the ultimate application, however, a critical step along the way to putting the laser in space is finding a way to efficiently cool it. While operating the laser becomes very hot and must be cooled to prevent overheating. On earth, this is accomplished by simply running cool tap water over the laser to keep it cool. But on a satellite, this is too inefficient. This would require too much water mass to be practical. Instead, we are investigating spray cooling as a means to cool the laser in microgravity. Spray cooling requires much less volume of fluid, and thus could be suitable for use on a satellite. We have inherited a 2.2 second Drop Tower rig to conduct our research with. In our experiments, water is pressurized with a compressed air tank and sprayed through a nozzle onto our test plate. We can vary the pressure applied to the water and the temperature of the plate before an experiment trial. The whole process takes place in simulated microgravity in the 2.2 second Drop Tower, and a high speed video camera records the spray as it hits the plate. We have made much progress in the past few weeks on these experiments. The rig originally did not have the capability to heat the test plate, but I did

  15. Roseomonas tokyonensis sp. nov. isolated from a biofilm sample obtained from a cooling tower in Tokyo, Japan.

    PubMed

    Furuhata, Katsunori; Ishizaki, Naoto; Edagawa, Akiko; Fukuyama, Masafumi

    2013-01-01

    Strain K-20(T), a Gram-negative, nonmotile, nonspore-forming and strictly aerobic coccobacillus, which produces a pale pink pigment (R2A agar medium, 30℃, seven days) was isolated from a sample of biofilm obtained from a cooling tower in Tokyo, Japan. A phylogenetic analysis of the 16S rRNA partial gene sequences (1,439 bp) showed that the strain (accession number: AB297501) was related to Roseomonas frigidaquae CW67(T) and Roseomonas stagni HS-69(T) with 97.4% and 96.9% sequence similarity, respectively. Strain K-20(T) formed a distinct cluster with Roseomonas frigidaquae CW67(T) in the phylogenetic tree at a high bootstrap value (93%); however, distance was recognized between the strains. In addition, the DNA-DNA hybridization level between strain K-20(T) and Roseomonas frigidaquae JCM 15073(T) was 33%. The taxonomic data indicate that K-20(T) (=JCM 14634(T) =KCTC 32152(T)) should be classified in the genus Roseomonas as the type strain of a novel species, Roseomonas tokyonensis sp. nov. PMID:24366626

  16. Investigation of N-acyl homoserine lactone (AHL) molecule production in Gram-negative bacteria isolated from cooling tower water and biofilm samples.

    PubMed

    Haslan, Ezgi; Kimiran-Erdem, Ayten

    2013-09-01

    In this study, 99 Gram-negative rod bacteria were isolated from cooling tower water, and biofilm samples were examined for cell-to-cell signaling systems, N-acyl homoserine lactone (AHL) signal molecule types, and biofilm formation capacity. Four of 39 (10 %) strains isolated from water samples and 14 of 60 (23 %) strains isolated from biofilm samples were found to be producing a variety of AHL signal molecules. It was determined that the AHL signal molecule production ability and the biofilm formation capacity of sessile bacteria is higher than planktonic bacteria, and there was a statistically significant difference between the AHL signal molecule production of these two groups (p < 0.05). In addition, it was found that bacteria belonging to the same species isolated from cooling tower water and biofilm samples produced different types of AHL signal molecules and that there were different types of AHL signal molecules in an AHL extract of bacteria. In the present study, it was observed that different isolates of the same strains did not produce the same AHLs or did not produce AHL molecules, and bacteria known as AHL producers did not produce AHL. These findings suggest that detection of signal molecules in bacteria isolated from cooling towers may contribute to prevention of biofilm formation, elimination of communication among bacteria in water systems, and blockage of quorum-sensing controlled virulence of these bacteria. PMID:23250628

  17. Preliminary study on the applicability of semi-geodesic winding in the design and manufacturing of composite towers

    NASA Astrophysics Data System (ADS)

    Kayran, A.; İbrahimoǧlu, C. S.

    2014-12-01

    During last twenty years, wind turbine manufacturers took the path of building larger machines to generate more electricity. However, the bigger the size became, the more material was required to support the loads, leading to great weight increases. Larger turbines and higher hub heights also resulted in larger tower base diameters which are limited considering their logistics. In many countries, the limit for transports with special permits maximizes the diameter to 4.5 metres. Considering this fact, the wind turbine market dominated by welded steel shell towers is looking for new structural solutions for their future turbines. Although, composite materials are not used as the structural material in the towers of today's turbines, the demand for larger wind turbines forces engineers to seek for alternative material systems with high specific strength and stiffness ratios to be used in towers. Inspired by the applicability of filament winding in tower production, in the present article we investigated the effect of semi-geodesic winding on the winding angle, thickness, stiffness coefficients and vibration characteristics of filament wound composite conical shells of revolution which simulate wind turbine towers at the structural level. Present study showed that the preset friction applied during semi-geodesic winding is an important design parameter which can be controlled to obtain gradually increasing thickness from tower top to the base of the tower, and favourably alter the dynamic characteristics of the composite towers.

  18. Lawrence Livermore National Laboratory (LLNL) Experimental Test Site (Site 300) Salinity Evaluation and Minimization Plan for Cooling Towers and Mechanical Equipment Discharges

    SciTech Connect

    Daily III, W D

    2010-02-24

    This document was created to comply with the Central Valley Regional Water Quality Control Board (CVRWQCB) Waste Discharge Requirement (Order No. 98-148). This order established new requirements to assess the effect of and effort required to reduce salts in process water discharged to the subsurface. This includes the review of technical, operational, and management options available to reduce total dissolved solids (TDS) concentrations in cooling tower and mechanical equipment water discharges at Lawrence Livermore National Laboratory's (LLNL's) Experimental Test Site (Site 300) facility. It was observed that for the six cooling towers currently in operation, the total volume of groundwater used as make up water is about 27 gallons per minute and the discharge to the subsurface via percolation pits is 13 gallons per minute. The extracted groundwater has a TDS concentration of 700 mg/L. The cooling tower discharge concentrations range from 700 to 1,400 mg/L. There is also a small volume of mechanical equipment effluent being discharged to percolation pits, with a TDS range from 400 to 3,300 mg/L. The cooling towers and mechanical equipment are maintained and operated in a satisfactory manner. No major leaks were identified. Currently, there are no re-use options being employed. Several approaches known to reduce the blow down flow rate and/or TDS concentration being discharged to the percolation pits and septic systems were reviewed for technical feasibility and cost efficiency. These options range from efforts as simple as eliminating leaks to implementing advanced and innovative treatment methods. The various options considered, and their anticipated effect on water consumption, discharge volumes, and reduced concentrations are listed and compared in this report. Based on the assessment, it was recommended that there is enough variability in equipment usage, chemistry, flow rate, and discharge configurations that each discharge location at Site 300 should be

  19. High temperature performance of high-efficiency, multi-layer solar selective coatings for tower applications

    SciTech Connect

    Gray, M. H.; Tirawat, R.; Kessinger, K. A.; Ndione, P. F.

    2015-05-01

    The roadmap to next-generation concentrating solar power plants anticipates a progression to central towers with operating temperatures in excess of 650°C. These higher temperatures are required to drive higher power-cycle efficiencies, resulting in lower cost energy. However, these conditions also place a greater burden on the materials making up the receiver. Any novel absorber material developed for next-generation receivers must be stable in air, cost effective, and survive thousands of heating and cooling cycles. The collection efficiency of a power tower plant can be increased if the energy absorbed by the receiver is maximized while the heat loss from the receiver to the environment is minimized. Thermal radiation losses can be significant (>7% annual energy loss) with receivers at temperatures above 650°C. We present progress toward highly efficient and durable solar selective absorbers (SSAs) intended for operating temperatures from 650°C to 1000°C. Selective efficiency (ηsel) is defined as the energy retained by the absorber, accounting for both absorptance and emittance, relative to the energy incident on the surface. The low emittance layers of multilayer SSAs are binary compounds of refractory metals whose material properties indicate that coatings formed of these materials should be oxidation resistant in air to 800-1200°C. On this basis, we initially developed a solar selective coating for parabolic troughs. This development has been successfully extended to meet the absorptance and emittance objectives for the more demanding, high temperature regime. We show advancement in coating materials, processing and designs resulting in the initial attainment of target efficiencies ηsel > 0.91 for proposed tower conditions. Additionally, spectral measurements show that these coatings continue to perform at targeted levels after cycling to temperatures of 1000°C in environments of nitrogen and forming gas.

  20. High temperature performance of high-efficiency, multi-layer solar selective coatings for tower applications

    DOE PAGESBeta

    Gray, M. H.; Tirawat, R.; Kessinger, K. A.; Ndione, P. F.

    2015-05-01

    The roadmap to next-generation concentrating solar power plants anticipates a progression to central towers with operating temperatures in excess of 650°C. These higher temperatures are required to drive higher power-cycle efficiencies, resulting in lower cost energy. However, these conditions also place a greater burden on the materials making up the receiver. Any novel absorber material developed for next-generation receivers must be stable in air, cost effective, and survive thousands of heating and cooling cycles. The collection efficiency of a power tower plant can be increased if the energy absorbed by the receiver is maximized while the heat loss from themore » receiver to the environment is minimized. Thermal radiation losses can be significant (>7% annual energy loss) with receivers at temperatures above 650°C. We present progress toward highly efficient and durable solar selective absorbers (SSAs) intended for operating temperatures from 650°C to 1000°C. Selective efficiency (ηsel) is defined as the energy retained by the absorber, accounting for both absorptance and emittance, relative to the energy incident on the surface. The low emittance layers of multilayer SSAs are binary compounds of refractory metals whose material properties indicate that coatings formed of these materials should be oxidation resistant in air to 800-1200°C. On this basis, we initially developed a solar selective coating for parabolic troughs. This development has been successfully extended to meet the absorptance and emittance objectives for the more demanding, high temperature regime. We show advancement in coating materials, processing and designs resulting in the initial attainment of target efficiencies ηsel > 0.91 for proposed tower conditions. Additionally, spectral measurements show that these coatings continue to perform at targeted levels after cycling to temperatures of 1000°C in environments of nitrogen and forming gas.« less

  1. Air cooled absorption chillers for solar cooling applications

    NASA Astrophysics Data System (ADS)

    Biermann, W. J.; Reimann, R. C.

    1982-03-01

    The chemical composition of a 'best' absorption refrigerant system is identified, and those properties of the system necessary to design hot water operated, air cooled chilling equipment are determined. Air cooled chillers from single family residential sizes into the commercial rooftop size range are designed and operated.

  2. Epidemiological investigation and case-control study: a Legionnaires' disease outbreak associated with cooling towers in Warstein, Germany, August-September 2013.

    PubMed

    Maisa, Anna; Brockmann, Ansgar; Renken, Frank; Lück, Christian; Pleischl, Stefan; Exner, Martin; Daniels-Haardt, Inka; Jurke, Annette

    2015-01-01

    Between 1 August and 6 September 2013, an outbreak of Legionnaires' disease (LD) with 159 suspected cases occurred in Warstein, North Rhine-Westphalia, Germany. The outbreak consisted of 78 laboratory-confirmed cases of LD, including one fatality, with a case fatality rate of 1%. Legionella pneumophila, serogroup 1, subtype Knoxville, sequence type 345, was identified as the epidemic strain. A case-control study was conducted to identify possible sources of infection. In univariable analysis, cases were almost five times more likely to smoke than controls (odds ratio (OR): 4.81; 95% confidence interval (CI): 2.33-9.93; p < 0.0001). Furthermore, cases were twice as likely to live within a 3 km distance from one identified infection source as controls (OR: 2.14; 95% CI: 1.09-4.20; p < 0.027). This is the largest outbreak of LD in Germany to date. Due to a series of uncommon events, this outbreak was most likely caused by multiple sources involving industrial cooling towers. Quick epidemiological assessment, source tracing and shutting down of potential sources as well as rapid laboratory testing and early treatment are necessary to reduce morbidity and mortality. Maintenance of cooling towers must be carried out according to specification to prevent similar LD outbreaks in the future. PMID:26607018

  3. Establish feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

    1987-01-01

    Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some application.

  4. Establish feasibility for providing passive cooling with solar updraft and evaporate downdraft chimneys

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

    1987-01-01

    Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some applications.

  5. Comparison of an impedance heating system to mineral insulated heat trace for power tower applications

    SciTech Connect

    Pacheco, J.E.; Kolb, W.J.

    1997-03-01

    A non-conventional type of heating system is being tested at Sandia National Laboratories for solar thermal power tower applications. In this system, called impedance heating, electric current flows directly through the pipe to maintain the desired temperature. The pipe becomes the resistor where the heat is generated. Impedance heating has many advantages over previously used mineral insulated (MI) heat trace. An impedance heating system should be much more reliable than heat trace cable since delicate junctions and cabling are not used and the main component, a transformer, is inherently reliable. A big advantage of impedance heating is the system can be sized to rapidly heat up the piping to provide rapid response times necessary in cyclic power plants such as solar power towers. In this paper, experimental results from testing an impedance heating system are compared to MI heat trace. The authors found impedance heating was able to heat piping rapidly and effectively. There were not significant stray currents and impedance heating did not affect instrumentation.

  6. A practical application combining wireless sensor networks and Internet of Things: Safety Management System for Tower Crane Groups.

    PubMed

    Zhong, Dexing; Lv, Hongqiang; Han, Jiuqiang; Wei, Quanrui

    2014-01-01

    The so-called Internet of Things (IoT) has attracted increasing attention in the field of computer and information science. In this paper, a specific application of IoT, named Safety Management System for Tower Crane Groups (SMS-TC), is proposed for use in the construction industry field. The operating status of each tower crane was detected by a set of customized sensors, including horizontal and vertical position sensors for the trolley, angle sensors for the jib and load, tilt and wind speed sensors for the tower body. The sensor data is collected and processed by the Tower Crane Safety Terminal Equipment (TC-STE) installed in the driver's operating room. Wireless communication between each TC-STE and the Local Monitoring Terminal (LMT) at the ground worksite were fulfilled through a Zigbee wireless network. LMT can share the status information of the whole group with each TC-STE, while the LMT records the real-time data and reports it to the Remote Supervision Platform (RSP) through General Packet Radio Service (GPRS). Based on the global status data of the whole group, an anti-collision algorithm was executed in each TC-STE to ensure the safety of each tower crane during construction. Remote supervision can be fulfilled using our client software installed on a personal computer (PC) or smartphone. SMS-TC could be considered as a promising practical application that combines a Wireless Sensor Network with the Internet of Things. PMID:25196106

  7. A Practical Application Combining Wireless Sensor Networks and Internet of Things: Safety Management System for Tower Crane Groups

    PubMed Central

    Zhong, Dexing; Lv, Hongqiang; Han, Jiuqiang; Wei, Quanrui

    2014-01-01

    The so-called Internet of Things (IoT) has attracted increasing attention in the field of computer and information science. In this paper, a specific application of IoT, named Safety Management System for Tower Crane Groups (SMS-TC), is proposed for use in the construction industry field. The operating status of each tower crane was detected by a set of customized sensors, including horizontal and vertical position sensors for the trolley, angle sensors for the jib and load, tilt and wind speed sensors for the tower body. The sensor data is collected and processed by the Tower Crane Safety Terminal Equipment (TC-STE) installed in the driver's operating room. Wireless communication between each TC-STE and the Local Monitoring Terminal (LMT) at the ground worksite were fulfilled through a Zigbee wireless network. LMT can share the status information of the whole group with each TC-STE, while the LMT records the real-time data and reports it to the Remote Supervision Platform (RSP) through General Packet Radio Service (GPRS). Based on the global status data of the whole group, an anti-collision algorithm was executed in each TC-STE to ensure the safety of each tower crane during construction. Remote supervision can be fulfilled using our client software installed on a personal computer (PC) or smartphone. SMS-TC could be considered as a promising practical application that combines a Wireless Sensor Network with the Internet of Things. PMID:25196106

  8. Testing and analysis of a wet-dry crossflow cooling Tower. Volume I: test program and results. Final report Jul 77-May 81

    SciTech Connect

    Ayers, D.L.; Hogan, M.R.; Hibar, A.E.; Lucheta, R.A.

    1981-07-01

    The report discusses the test program and performance analysis of a single-cell mechanical-draft wet/dry cooling tower in Cliffside, NC. Objectives of the program were to obtain performance data and results on mass transfer, heat transfer, fluid flow, plume formation, and acoustic characteristics for comparison with models/theories. Correlations are presented for the wet-fill mass transfer coefficient, wet-fill water loss, Colburn j-factor for the finned tubes, and fan efficiency in terms of one or more of the following: water loading in the tubes, air loading over the fins, log mean humidity difference, outlet water temperature, Reynolds number, and air-flow rate. Acoustic data were fitted to a series of curves for each of the eight octave bands. Attempts to model plume data failed. The report also describes the test facility, test procedures, instrumentation, data acquisition, and data reduction.

  9. Modeling of the Evaporative Cooling of Running-Down Liquid Films in the Slit Channel of the Spraying Device of a Cooling Tower

    NASA Astrophysics Data System (ADS)

    Dashkov, G. V.; Malenko, G. L.; Solodukhin, A. D.; Tyutyuma, V. D.

    2014-11-01

    This paper presents the results of computational modeling of the nonstationary evaporative cooling of a liquid film running down a vertical surface cooled by a turbulent vapor-air counterflow. The heat and mass transfer problem has been formulated in conjugate form. The calculation data on the total heat flow density at the interface for various instants of time are given.

  10. Convection towers

    DOEpatents

    Prueitt, Melvin L.

    1994-01-01

    Convection towers which are capable of cleaning the pollution from large quantities of air and of generating electricity utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity. Other embodiments may also provide fresh water, and operate in an updraft mode.

  11. Convection towers

    DOEpatents

    Prueitt, Melvin L.

    1996-01-01

    Convection towers which are capable of cleaning the pollution from large quantities of air, of generating electricity, and of producing fresh water utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity, and condensers produce fresh water.

  12. Convection towers

    DOEpatents

    Prueitt, Melvin L.

    1995-01-01

    Convection towers which are capable of cleaning the pollution from large quantities of air, of generating electricity, and of producing fresh water utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity, and condensers produce fresh water.

  13. Convection towers

    DOEpatents

    Prueitt, M.L.

    1996-01-16

    Convection towers which are capable of cleaning the pollution from large quantities of air, of generating electricity, and of producing fresh water utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity, and condensers produce fresh water. 6 figs.

  14. The Physics of Shot Towers

    NASA Astrophysics Data System (ADS)

    Lipscombe, Trevor C.; Mungan, Carl E.

    2012-04-01

    In the late 18th and throughout the 19th century, lead shot for muskets was prepared by use of a shot tower. Molten lead was poured from the top of a tower and, during its fall, the drops became spherical under the action of surface tension. In this article, we ask and answer the question: How does the size of the lead shot depend on the height of the tower? In the process, we explain the basic technology underlying an important historical invention (the shot tower) and use simple physics (Newtonian mechanics and the thermodynamic laws of cooling) to model its operation.

  15. Water cooled absorption chillers for solar cooling applications

    NASA Astrophysics Data System (ADS)

    Biermann, W. J.; Reimann, R. C.

    1982-03-01

    A broad line of absorption chillers designed to operate with hot fluids at as low a temperature as practical while rejecting heat to a stream of water was developed. A packaging concept for solar application in which controls, pumps, valves and other system components could be factor assembled into a unitary solar module was investigated.

  16. Convection towers

    DOEpatents

    Prueitt, M.L.

    1994-02-08

    Convection towers which are capable of cleaning the pollution from large quantities of air and of generating electricity utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity. Other embodiments may also provide fresh water, and operate in an updraft mode. 5 figures.

  17. Establish feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys. Final report, June 15, 1984--December 31, 1987

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

    1987-12-31

    Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some application.

  18. Establish feasibility for providing passive cooling with solar updraft and evaporate downdraft chimneys. Final report, June 15, 1984--December 31, 1987

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

    1987-12-31

    Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some applications.

  19. Biomedical Application of Aerospace Personal Cooling Systems

    NASA Technical Reports Server (NTRS)

    Ku, Yu-Tsuan E.; Lee, Hank C.; Montgomery, Leslie D.; Webbon, Bruce W.; Kliss, Mark (Technical Monitor)

    1997-01-01

    Personal thermoregulatory systems which are used by astronauts to alleviate thermal stress during extravehicular activity have been applied to the therapeutic management of multiple sclerosis. However, little information is available regarding the physiologic and circulatory changes produced by routine operation of these systems. The objectives of this study were to compare the effectiveness of two passive and two active cooling vests and to measure the body temperature and circulatory changes produced by each cooling vest configuration. The MicroClimate Systems and the Life Enhancement Tech(LET) lightweight liquid cooling vests, the Steele Vest and LET's Zipper Front Garment were used to cool the chest region of 10 male and female subjects (25 to 55 yr.) in this study. Calf, forearm and finger blood flows were measured using a tetrapolar impedance rheograph. The subjects, seated in an upright position at normal room temperature (approx.22C), were tested for 60 min. with the cooling system operated at its maximum cooling capacity. Blood flows were recorded continuously using a computer data acquisition system with a sampling frequency of 250 Hz. Oral, right and left ear temperatures and cooling system parameters were logged manually every 5 min. Arm, leg, chest and rectal temperatures; heart rate; respiration; and an activity index were recorded continuously on a U.F.I., Inc. Biolog ambulatory monitor. In general, the male and female subjects' oral and ear temperature responses to cooling were similar for all vest configurations tested. Oral temperatures during the recovery period were significantly (P<0.05) lower than during the control period, approx. 0.2 - 0.5C, for both men and women wearing any of the four different garments. The corresponding ear temperatures were significantly (P<0.05) decreased approx.0.2 - 0.4C by the end of the recovery period. Compared to the control period, no significant differences were found in rectal temperatures during cooling and

  20. Distribution of monoclonal antibody subgroups and sequence-based types among Legionella pneumophila serogroup 1 isolates derived from cooling tower water, bathwater, and soil in Japan.

    PubMed

    Amemura-Maekawa, Junko; Kikukawa, Kiyomi; Helbig, Jürgen H; Kaneko, Satoko; Suzuki-Hashimoto, Atsuko; Furuhata, Katsunori; Chang, Bin; Murai, Miyo; Ichinose, Masayuki; Ohnishi, Makoto; Kura, Fumiaki

    2012-06-01

    Legionella pneumophila serogroup (SG) 1 is the most frequent cause of legionellosis. This study analyzed environmental isolates of L. pneumophila SG 1 in Japan using monoclonal antibody (MAb) typing and sequence-based typing (SBT). Samples were analyzed from bathwater (BW; n = 50), cooling tower water (CT; n = 50), and soil (SO; n = 35). The distribution of MAb types varied by source, with the most prevalent types being Bellingham (42%), Oxford (72%), and OLDA (51%) in BW, CT, and SO, respectively. The ratios of MAb 3/1 positive isolates were 26, 2, and 14% from BW, CT, and SO, respectively. The environmental isolates from BW, CT, and SO were divided into 34 sequence types (STs; index of discrimination [IOD] = 0.973), 8 STs (IOD = 0.448), and 11 STs (IOD = 0.879), respectively. Genetic variation among CT isolates was smaller than seen in BW and SO. ST1 accounted for 74% of the CT isolates. The only common STs between (i) BW and CT, (ii) BW and SO, and (iii) CT and SO were ST1, ST129, and ST48, respectively, suggesting that each environment constitutes an independent habitat. PMID:22492442

  1. Collapsible Towers

    NASA Technical Reports Server (NTRS)

    1976-01-01

    NASA needed a means of orbiting a large radio telescope antenna. Astro Research Corporation developed a new structure that was strong, lightweight, folded into a small storage space, and could be erected by rotation. Later they adapted it to commercial use. Today the "Astromast" tower consists of tubular aluminum alloy and stainless steel members that deploy into small three-sided bays, each made rigid by six diagonal cables. All joints are flexible to permit folding and unfolding. Tower packs into container 5% of its height, can be erected without tools and is reusable. Tower has won "Design of the Year" award from Machine Design. Variations include portable emergency bridges and commercial scaffolding.

  2. Spray Cooling Processes for Space Applications

    NASA Technical Reports Server (NTRS)

    Kizito, John P.; VanderWal, Randy L.; Berger, Gordon; Tryggvason, Gretar

    2004-01-01

    The present paper reports ongoing work to develop numerical and modeling tools used to design efficient and effective spray cooling processes and to determine characteristic non-dimensional parametric dependence for practical fluids and conditions. In particular, we present data that will delineate conditions towards control of the impingement dynamics of droplets upon a heated substrate germane to practical situations.

  3. Survey of reinjection experience from groundwater cooling applications

    SciTech Connect

    Snyder, M.; Lee, C.H.

    1980-09-01

    The use of groundwater for cooling applications is a common practice throughout the country wherever an adequate supply of water exists. However, the reinjection of the cooling water to water-bearing strata is not as widely practiced. The literature pertaining to reinjection of heated water is not well documented. To fulfill the need for more information, a study was conducted to identify and document at least 30 sites where reinjection of grundwater from cooling applications was being (or had been) performed. The information obtained on each site was compiled and analyzed, the site described briefly and cooling and reinjection problems characterized. The end result of this study was to establish a data base of reinjection experience based on a variety of sites around the country with different hydrogeologic characteristics and cooling systems. These data are presented.

  4. Low cost solar energy collection for cooling applications

    NASA Astrophysics Data System (ADS)

    Wilhelm, W. G.

    1981-06-01

    Solar energy collector designs utilizing thin-film polymeric materials in the absorber and glazing are investigated. The main objective is dramatic cost reduction consistent with acceptable performance and life. These collectors now appear capable of high temperature applications including desiccant and absorption cooling (1500 to 2000 F). The performance and economics of the thin-film collector are compared with those of conventional flat-plate designs in cooling applications.

  5. Effect of chlorine and temperature on free-living protozoa in operational man-made water systems (cooling towers and hot sanitary water systems) in Catalonia.

    PubMed

    Canals, Oriol; Serrano-Suárez, Alejandra; Salvadó, Humbert; Méndez, Javier; Cervero-Aragó, Sílvia; Ruiz de Porras, Vicenç; Dellundé, Jordi; Araujo, Rosa

    2015-05-01

    In recent decades, free-living protozoa (FLP) have gained prominence as the focus of research studies due to their pathogenicity to humans and their close relationship with the survival and growth of pathogenic amoeba-resisting bacteria. In the present work, we studied the presence of FLP in operational man-made water systems, i.e. cooling towers (CT) and hot sanitary water systems (HSWS), related to a high risk of Legionella spp. outbreaks, as well as the effect of the biocides used, i.e. chlorine in CT and high temperature in HSWS, on FLP. In CT samples, high-chlorine concentrations (7.5 ± 1.5 mg chlorine L(-1)) reduced the presence of FLP by 63.8 % compared to samples with low-chlorine concentrations (0.04 ± 0.08 mg chlorine L(-1)). Flagellates and amoebae were observed in samples collected with a level of 8 mg chlorine L(-1), which would indicate that some FLP, including the free-living amoeba (FLA) Acanthamoeba spp., are resistant to the discontinuous chlorine disinfection method used in the CT studied. Regarding HSWS samples, the amount of FLP detected in high-temperatures samples (53.1 ± 5.7 °C) was 38 % lower than in low-temperature samples (27.8 ± 5.8 °C). The effect of high temperature on FLP was chiefly observed in the results obtained by the culture method, in which there was a clear reduction in the presence of FLP at temperatures higher than 50 °C, but not in those obtained by PCR. The findings presented here show that the presence of FLP in operational man-made water systems should be taken into account in future regulations. PMID:25410311

  6. A numerical model for gas-droplet flow application to liquid spray and cooling towers

    NASA Astrophysics Data System (ADS)

    Weinacht, P.; Buchlin, J. M.

    1982-07-01

    A two dimensional model consisting of coupled sets of equations governing the gas and liquid phases is presented. Modeling the gas phase as a continuum allows use of the Navier-Stokes equations with momentum source terms included. The particle-gas momentum exchange and the influence of the gas flow on the droplet trajectories results in a coupling of both of these sets of equations. Numerical solution of these equations is made in an iterative fashion by solving first the liquid phase equations and then the gas phase equations until a steady state solution is reached. Solution of the liquid phase equations by a fourth order Runge-Kutta method allows subsequent determination of the droplet-gas momentum exchange field. The degrading effect of wind on a spray curtain is demonstrated, though calculations show that curtain performance can be improved by tilting the nozzle into the wind.

  7. Evaluation of cooling concepts for high power avionics applications

    NASA Astrophysics Data System (ADS)

    Flynn, E. M.

    1992-10-01

    Evaluations were made of emerging cooling technologies having potential to remove 100 W/sq cm steady state heat dissipation while holding chip junction temperature to 90 C. Several constraints were imposed on the cooler due to the intended application of cooling fighter aircraft electronics. Constraints included a practical lower limit on coolant supply temperature, the preference for a nontoxic, nonflammable, and nonfreezing coolant, the need to minimize weight and volume, and operation in an accelerating environment. Evaluation factors included aircraft system impact, cooler development status, reliability and maintainability, safety, etc. This paper describes the cooling concepts and assessments made as to their relative performance in a fighter aircraft environment.

  8. Cool-and Unusual-CAD Applications

    ERIC Educational Resources Information Center

    Calhoun, Ken

    2004-01-01

    This article describes several very useful applications of AutoCAD that may lie outside the normal scope of application. AutoCAD commands used in this article are based on AutoCAD 2000I. The author and his students used a Hewlett Packard 750C DesignJet plotter for plotting. (Contains 5 figures and 5 photos.)

  9. Rapunzel's Tower

    ERIC Educational Resources Information Center

    Depp, Sheryl

    2007-01-01

    Children's literature often inspires the author's lessons, and reading to her primary students motivates their participation. In this article, the author presents and describes her lesson which is based on the book "Falling for Rapunzel" by Leah Wilcox. Students created a fairy tale tower in this lesson, which took place over three class periods.…

  10. Overview of Helium Cooled System Applications with RELAP at ENEA

    SciTech Connect

    Meloni, Paride; Casamirra, Maddalena

    2006-07-01

    Some years ago, within the framework of the study for the International Thermonuclear Experimental Reactor (ITER), ENEA assessed the RELAP5 code capability to simulate Helium cooled systems on the experimental data provided by the helium facility HEFUS3 (Brasimone, Italy). This activity allowed acquiring a certain experience on the limits and capabilities of the code that, in the following years, was used for a wide range of applications concerning transient and accident analysis of helium cooled systems. At first the paper summarizes the results of the assessment activity, then describes the accident analyses performed for the conceptual study of the Fusion Power Reactor with Helium-Cooled Pebble Bed Blanket (HCPBB) and the studies to support the safety design of the gas cooled Accelerator Driven System (ADS) concept. The paper concludes highlighting the RELAP adaptations to realize within the framework of the feasibility studies for a combined cycle concept of the Very High Temperature Reactor (VHTR). (authors)

  11. Solar thermal power towers

    NASA Astrophysics Data System (ADS)

    Kreith, F.; Meyer, R. T.

    1984-07-01

    The solar thermal central receiver technology, known as solar power towers, is rapidly evolving to a state of near-term energy availability for electrical power generation and industrial process heat applications. The systems consist of field arrays of heliostat reflectors, a central receiver boiler, short term thermal storage devices, and either turbine-generators or heat exchangers. Fluid temperatures up to 550 C are currently achievable, and technology developments are underway to reach 1100 C. Six solar power towers are now under construction or in test operation in five countries around the world.

  12. Special applications of gas-cooled reactors

    SciTech Connect

    Peinado, C.O.

    1981-02-01

    The HTGR technology has been demonstrated by Peach Bottom, Fort St. Vrain, and AVR. Another member of the GCR family is the GCFR. Energy requirements for process heat applications of the HTGR high-temperature nuclear heat source are tabulated. 2 tables. (DLC)

  13. Cryogenic Cooling for Myriad Applications-A STAR Is Born

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Cryogenics, the science of generating extremely low temperatures, has wide applicability throughout NASA. The Agency employs cryogenics for rocket propulsion, high-pressure gas supply, breathable air in space, life support equipment, electricity, water, food preservation and packaging, medicine, imaging devices, and electronics. Cryogenic liquid oxygen and liquid hydrogen systems are also replacing solid rocket motor propulsion systems in most of the proposed launch systems, a reversion to old-style liquid propellants. In the late 1980s, NASA wanted a compact linear alternator/motor with reduced size and mass, as well as high efficiency, that had unlimited service life for use in a thermally driven power generator for space power applications. Prior development work with free-piston Stirling converters (a Stirling engine integrated with a linear actuator that produces electrical power output) had shown the promise of that technology for high-power space applications. A dual use for terrestrial applications exists for compact Stirling converters for onsite combined heat and power units. The Stirling cycle is also usable in reverse as a refrigeration cycle suitable for cryogenic cooling, so this Stirling converter work promised double benefits as well as dual uses. The uses for cryogenic coolers within NASA abound; commercial applications are similarly wide-ranging, from cooling liquid oxygen and nitrogen, to cryobiology and bio-storage, cryosurgery, instrument and detector cooling, semiconductor manufacturing, and support service for cooled superconducting power systems.

  14. Virtual Tower

    SciTech Connect

    Wayne, R.A.

    1997-08-01

    The primary responsibility of an intrusion detection system (IDS) operator is to monitor the system, assess alarms, and summon and coordinate the response team when a threat is acknowledged. The tools currently provided to the operator are somewhat limited: monitors must be switched, keystrokes must be entered to call up intrusion sensor data, and communication with the response force must be maintained. The Virtual tower is an operator interface assembled from low-cost commercial-off-the-shelf hardware and software; it enables large amounts of data to be displayed in a virtual manner that provides instant recognition for the operator and increases assessment accuracy in alarm annunciator and control systems. This is accomplished by correlating and fusing the data into a 360-degree visual representation that employs color, auxiliary attributes, video, and directional audio to prompt the operator. The Virtual Tower would be a valuable low-cost enhancement to existing systems.

  15. New Directions for Evaporative Cooling Systems.

    ERIC Educational Resources Information Center

    Robison, Rita

    1981-01-01

    New energy saving technology can be applied to older cooling towers; in addition, evaporative chilling, a process that links a cooling tower to the chilling equipment, can reduce energy use by 80 percent. (Author/MLF)

  16. Actively Cooled SLMS(TM) Technology for HEL Applications

    NASA Technical Reports Server (NTRS)

    Jacoby, Marc T.; Goodman, William A.; Reily, Jack C.; Kegley, Jeffrey R.; Haight, Harlan J.; Tucker, John; Wright, Ernest R.; Hogue, William D.

    2005-01-01

    Mr. Jacoby is the Chief Scientist for Schafer's Lightweight Optical Systems business area with twenty four years experience in laser and optical systems for space and military applications. He and colleague Dr. Goodman conceived and developed Silicon Lightweight Mirrors (SLMS(TM)) technologies for space applications from the extreme UV to FAR IR wavelengths. Schafer has demonstrated two different methods for actively cooling our Silicon Lightweight Mirrors (SLMS(TM)) technology. Direct internal cooling was accomplished by flowing liquid nitrogen through the continuous open cell core of the SLMS(TM) mirror. Indirect external cooling was accomplished by flowing liquid nitrogen through a CTE matched Cesic square-tube manifold that was bonded to the back of the mirror in the center. Testing was done in the small 4-foot thermal/vacuum chamber located at the NASA/MSFC X-Ray Calibration Facility. Seven thermal diodes were located over the front side of the 5 inch diameter mirror and one was placed on the outlet side of the Cesic manifold. Results indicate that the mirror reaches steady state at 82K in less than four minutes for both cooling methods. The maximum temperature difference of the eight diodes was less than 200 mK when the mirror was internally cooled and covered with MLI to insulate it from the large 300 K aluminum plate that was used to mount it.

  17. Building heating and cooling applications thermal energy storage program overview

    NASA Technical Reports Server (NTRS)

    Eissenberg, D. M.

    1980-01-01

    Thermal energy storage technology and development of building heating and cooling applications in the residential and commercial sectors is outlined. Three elements are identified to undergo an applications assessment, technology development, and demonstration. Emphasis is given to utility load management thermal energy system application where the stress is on the 'customer side of the meter'. Thermal storage subsystems for space conditioning and conservation means of increased thermal mass within the building envelope and by means of low-grade waste heat recovery are covered.

  18. Preliminary design package for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Summarized preliminary design information on activities associated with the development, delivery and support of solar heating and cooling systems is given. These systems are for single family dwellings and commercial applications. The heating/cooling system use a reversible vapor compression heat pump that is driven in the cooling mode by a Rankine power loop, and in the heating mode by a variable speed electric motor. The heating/cooling systems differ from the heating-only systems in the arrangement of the heat pump subsystem and the addition of a cooling tower to provide the heat sink for cooling mode operation.

  19. Cooled variable nozzle radial turbine for rotor craft applications

    NASA Technical Reports Server (NTRS)

    Rogo, C.

    1981-01-01

    An advanced, small 2.27 kb/sec (5 lbs/sec), high temperature, variable area radial turbine was studied for a rotor craft application. Variable capacity cycles including single-shaft and free-turbine engine configurations were analyzed to define an optimum engine design configuration. Parametric optimizations were made on cooled and uncooled rotor configurations. A detailed structural and heat transfer analysis was conducted to provide a 4000-hour life HP turbine with material properties of the 1988 time frame. A pivoted vane and a moveable sidewall geometry were analyzed. Cooling and variable geometry penalties were included in the cycle analysis. A variable geometry free-turbine engine configuration with a design 1477K (2200 F) inlet temperature and a compressor pressure ratio of 16:1 was selected. An uncooled HP radial turbine rotor with a moveable sidewall nozzle showed the highest performance potential for a time weighted duty cycle.

  20. Drop tower with no aerodynamic drag

    NASA Technical Reports Server (NTRS)

    Kendall, J. M., Jr.

    1981-01-01

    Cooling air accelerated to match velocity of falling object eliminates drag. 3 meter drop tower with suction fan and specific geometry causes air to accelerate downward at 1 g. Although cooling of molten material released from top is slow because surrounding air moves with it, drop remains nearly spherical.

  1. Third international workshop on ice storage for cooling applications

    SciTech Connect

    Gorski, A.J.

    1986-04-01

    The third international workshop on ice storage for cooling applications which was informal and interactive in nature, was open to persons interested in all ice-growing technologies and in ice storage, both seasonal and diurnal. Presentations were made on some 20 topics, ranging from freezers in Alaska to ice cooling of commercial jet aircraft. Workshop tours included visits to ice-storage systems at Commonwealth Edison's facilities in Bolingbrook and Des Plaines Valley, the A.C. Neilsen builing in Northbrook, and the new State of Illinois Center in Chicago. The first workshop in the present series considered the future of ice storage and predicted applications in the agricultural sector, desalinization, and commercial ice production. Progress has been rapid in the intervening two years, and an important topic at the third workshop was the possible use of ''warm ices'' (clathrate hydrates) for energy storage. This report consists primarily of abstracts of presentations made at the workshop. Persons wishing to obtain further information about particular papers should contact the speakers directly; speakers' addresses and telephone numbers are listed in this report.

  2. Experiences in solar cooling systems

    NASA Astrophysics Data System (ADS)

    Ward, D. S.

    The results of performance evaluations for nine solar cooling systems are presented, and reasons fow low or high net energy balances are discussed. Six of the nine systems are noted to have performed unfavorably compared to standard cooling systems due to thermal storage losses, excessive system electrical demands, inappropriate control strategies, poor system-to-load matching, and poor chiller performance. A reduction in heat losses in one residential unit increased the total system efficiency by 2.5%, while eliminating heat losses to the building interior increased the efficiency by 3.3%. The best system incorporated a lithium bromide absorption chiller and a Rankine cycle compression unit for a commercial application. Improvements in the cooling tower and fan configurations to increase the solar cooling system efficiency are indicated. Best performances are expected to occur in climates inducing high annual cooling loads.

  3. Simulation of Laser Cooling and Trapping in Engineering Applications

    NASA Technical Reports Server (NTRS)

    Ramirez-Serrano, Jaime; Kohel, James; Thompson, Robert; Yu, Nan; Lunblad, Nathan

    2005-01-01

    An advanced computer code is undergoing development for numerically simulating laser cooling and trapping of large numbers of atoms. The code is expected to be useful in practical engineering applications and to contribute to understanding of the roles that light, atomic collisions, background pressure, and numbers of particles play in experiments using laser-cooled and -trapped atoms. The code is based on semiclassical theories of the forces exerted on atoms by magnetic and optical fields. Whereas computer codes developed previously for the same purpose account for only a few physical mechanisms, this code incorporates many more physical mechanisms (including atomic collisions, sub-Doppler cooling mechanisms, Stark and Zeeman energy shifts, gravitation, and evanescent-wave phenomena) that affect laser-matter interactions and the cooling of atoms to submillikelvin temperatures. Moreover, whereas the prior codes can simulate the interactions of at most a few atoms with a resonant light field, the number of atoms that can be included in a simulation by the present code is limited only by computer memory. Hence, the present code represents more nearly completely the complex physics involved when using laser-cooled and -trapped atoms in engineering applications. Another advantage that the code incorporates is the possibility to analyze the interaction between cold atoms of different atomic number. Some properties that cold atoms of different atomic species have, like cross sections and the particular excited states they can occupy when interacting with each other and light fields, play important roles not yet completely understood in the new experiments that are under way in laboratories worldwide to form ultracold molecules. Other research efforts use cold atoms as holders of quantum information, and more recent developments in cavity quantum electrodynamics also use ultracold atoms to explore and expand new information-technology ideas. These experiments give a hint

  4. Passively cooled diode laser for high-power applications

    NASA Astrophysics Data System (ADS)

    Bonati, Guido F.; Hennig, Petra; Schmidt, Karsten

    2004-06-01

    For the usage of diode lasers in industrial applications, customers ask today for expected lifetimes of more then 30.000 hours. To match the request for low costs per Watt as well, the output power has to be as high as possible. To achieve a maximum power out of a diode laser bar, heat removal must be extremely efficient. Today, micro channel heatsinks (MCHS) are the only way to achieve the high power level of 50W. But due to erosion/corrosion effects the lifetime of MCHS is limited at 15000...20.000 hours today. Finally we have to determine that for selected semiconductor materials not the semiconductor but the heatsink is limiting the expected lifetime of high power diode lasers today. Passive heat sinks based on solid copper are not limiting lifetime expectations in any way. But as cooling efficiency is lower, the power has to be reduced to a level of 30...40W. The first time ever, the JENOPTIK Laserdiode can present today a cooling technique that combines the passive cooling of a diode laser bar with the optical output a power of a bar, mounted on a MCHS. Using a special heat exchanger called DCB (patent pending) we were able to increase the power to 50W per bar while looking forward to extend the expected lifetime to more than 30.000 hours for selected materials. Restrictions on the quality of the water by means of deionization grade or PH- level are no longer necessary. The device is operating with regular water. The flow rate is as low as on MCHS, the pressure drop over the DCB is comparable. Additionally, the measurements will show an even lower thermal resistance compared to MCHS. The second generationof engineering samples is built up for pumping rows. A vertical stack design will be available for evaluating purposes soon. All these efforts are part of the JENOPTIK Laserdiode's LongLifeTechnology.

  5. Applicability of surrogate-based MCMC-Bayesian inversion of CLM at flux tower sites with various climate and soil conditions

    NASA Astrophysics Data System (ADS)

    Hou, Z.; Ray, J.; Huang, M.; Swiler, L.

    2014-12-01

    Community Land Model (CLM) parameters affect model simulations in different ways. Previous work has been done to evaluate the significance of the effects of hydrological parameters, and their identifiability from heat flux and/or streamflow observations at different flux tower sites with various climate and soil conditions. Such exploratory parameter screening and sensitivity analysis provide guidance on model calibration design; meanwhile, the exploratory ensemble simulations, associated with effective sampling of the input parameter space, can be used to developed reliable surrogate models linking input parameters and output responses such as latent heat fluxes (LH). In this study, we test the applicability of a surrogate-based Markov chain Monte Carlo (MCMC) inversion method, at different flux tower sites, to identify favorable climate and soil conditions for such inversion efforts. The unknown parameters are decided given our previous parameter screening work, samples are then generated using the quasi-Monte Carlo approach based on the prior distributions of the unknown parameters determined given minimum-relative-entropy theory. The sample sets are ingested into CLM to generate simulations that can be used for fitting polynomial surrogates up to the third order. The surrogates are finalized by compromising the training and testing errors, and integrated in the MCMC-Bayesian framework at each flux tower site. The applicability of the calibration approach for different site conditions is discussed.

  6. Application of metallic nanoparticle suspensions in advanced cooling systems

    SciTech Connect

    Lee, S.; Choi, S.U.S.

    1996-12-31

    In the development of energy-efficient heat transfer fluids that are required in many cooling applications, low thermal conductivity is a primary limitation. However, it is well known that at room temperature, metals in solid form have orders-of-magnitude higher thermal conductivities than those of fluids. Therefore, the thermal conductivities of fluids that contain suspended solid metallic particles are expected to be significantly enhanced over those of conventional heat transfer fluids. In fact, numerous theoretical and experimental studies of the effective thermal conductivity of dispersions that contain solid particles have been conducted since Maxwell`s theoretical was published more than 100 years ago. However, all of the studies on thermal conductivity of suspensions have been confined to millimeter- or micrometer-sized particles.

  7. 40 CFR 463.10 - Applicability; description of the contact cooling and heating water subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... contact cooling and heating water subcategory. 463.10 Section 463.10 Protection of Environment... FORMING POINT SOURCE CATEGORY Contact Cooling and Heating Water Subcategory § 463.10 Applicability; description of the contact cooling and heating water subcategory. This subpart applies to discharges...

  8. Cellular Phone Towers

    MedlinePlus

    ... the call. How are people exposed to the energy from cellular phone towers? As people use cell ... where people can be exposed to them. The energy from a cellular phone tower antenna, like that ...

  9. High temperature gas-cooled reactor: gas turbine application study

    SciTech Connect

    Not Available

    1980-12-01

    The high-temperature capability of the High-Temperature Gas-Cooled Reactor (HTGR) is a distinguishing characteristic which has long been recognized as significant both within the US and within foreign nuclear energy programs. This high-temperature capability of the HTGR concept leads to increased efficiency in conventional applications and, in addition, makes possible a number of unique applications in both electrical generation and industrial process heat. In particular, coupling the HTGR nuclear heat source to the Brayton (gas turbine) Cycle offers significant potential benefits to operating utilities. This HTGR-GT Application Study documents the effort to evaluate the appropriateness of the HTGR-GT as an HTGR Lead Project. The scope of this effort included evaluation of the HTGR-GT technology, evaluation of potential HTGR-GT markets, assessment of the economics of commercial HTGR-GT plants, and evaluation of the program and expenditures necessary to establish HTGR-GT technology through the completion of the Lead Project.

  10. Performance specification for control tower display systems

    NASA Astrophysics Data System (ADS)

    Aleva, Denise L.; Meyer, Frederick M.

    2003-09-01

    Personnel in airport control towers monitor and direct the takeoff of outgoing aircraft, landing of incoming aircraft and all movements of aircraft on the ground. Although the primary source of information for the Local Controller, Assistant Local Controller and the Ground Controller is the real world viewed through the windows of the control tower, electronic displays are also used to provide situation awareness. Due to the criticality of the work to be performed by the controllers and the rather unique environment of the air traffic control tower, display hardware standards, which have been developed for general use, are not directly applicable. The Federal Aviation Administration (FAA) requested assistance of Air Force Research Laboratory Human Effectiveness Directorate in producing a document which can be adopted as a Tower Display Standard usable by display engineers, human factors practitioners and system integrators. Particular emphasis was placed on human factors issues applicable to the control tower environment and controller task demands.

  11. State waste discharge permit application: 400 Area secondary cooling water

    SciTech Connect

    Not Available

    1992-12-01

    This document constitutes the Washington Administrative Code 173-216 State Waste Discharge Permit Application that serves as interim compliance as required by the Consent Order DE 91NM-177, for the 400 Area Secondary Cooling Water stream. As part of the Hanford Federal Facility Agreement and Consent Order negotiations, the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site which affect groundwater or have the potential to affect groundwater would be subject to permitting under the structure of Chapter 173-216 (or 173-218 where applicable) of the Washington Administrative Code, the State Waste Discharge Permitting Program. As a result of this decision, the Washington State Department of Ecology and the US Department of Energy, Richland Operations Office entered in to Consent Order DE 91NM-177. The Consent Order DE 91NM-177 requires a series of permitting activities for liquid effluent discharges.

  12. Towers for Offshore Wind Turbines

    NASA Astrophysics Data System (ADS)

    Kurian, V. J.; Narayanan, S. P.; Ganapathy, C.

    2010-06-01

    Increasing energy demand coupled with pollution free production of energy has found a viable solution in wind energy. Land based windmills have been utilized for power generation for more than two thousand years. In modern times wind generated power has become popular in many countries. Offshore wind turbines are being used in a number of countries to tap the energy from wind over the oceans and convert to electric energy. The advantages of offshore wind turbines as compared to land are that offshore winds flow at higher speed than onshore winds and the more available space. In some land based settings, for better efficiency, turbines are separated as much as 10 rotor diameters from each other. In offshore applications where only two wind directions are likely to predominate, the distances between the turbines arranged in a line can be shortened to as little as two or four rotor diameters. Today, more than a dozen offshore European wind facilities with turbine ratings of 450 kw to 3.6 MW exist offshore in very shallow waters of 5 to 12 m. Compared to onshore wind turbines, offshore wind turbines are bigger and the tower height in offshore are in the range of 60 to 80 m. The water depths in oceans where offshore turbines can be located are within 30 m. However as the distance from land increases, the costs of building and maintaining the turbines and transmitting the power back to shore also increase sharply. The objective of this paper is to review the parameters of design for the maximum efficiency of offshore wind turbines and to develop types offshore towers to support the wind turbines. The methodology of design of offshore towers to support the wind turbine would be given and the environmental loads for the design of the towers would be calculated for specific cases. The marine corrosion on the towers and the methods to control the corrosion also would be briefly presented. As the wind speeds tend to increase with distance from the shore, turbines build father

  13. A cooling water system copper corrosion study

    SciTech Connect

    Pulkrabek, J.W.

    1998-07-01

    The plant has four units that have been operating normally for 12--33 years. Two of the units are 70 MW sister units that have copper alloy once-through condensers. The other two units are 350 MW and 500 MW units with copper alloy condensers and cooling towers. No cooling water related tube leaks had been experienced. Until 1993, the only chemicals used were sulfuric acid for pH control of the cooling tower systems and chlorine for biological control. The units were chlorinated for one hour per day per condenser. In early July 1992, their copper grab sample at the plant discharge to the river exceeded the weekly environmental limit. In fact, it was so high that there was a slim chance of coming in under their monthly average copper limit unless something was done quickly. The result of this incident was an extensive study of their plant wastewater and cooling systems. The study revealed that the elevated copper problem had existed sporadically for several years. Initially, copper control was achieved by altering the wastewater treatment processes and cooling tower blowdown flow path. Two extended trials, one with tolyltriazole (TTA) and one with a chemically modified benzotriazole (BZT) were performed. Optimal control of copper corrosion was eventually achieved by the application of a TTA treatment program in which the feed rates are adjusted based on on-line corrosion monitoring measurements. This report documents experiences and results over the past six years.

  14. State waste discharge permit application for cooling water and condensate discharges

    SciTech Connect

    Haggard, R.D.

    1996-08-12

    The following presents the Categorical State Waste Discharge Permit (SWDP) Application for the Cooling Water and Condensate Discharges on the Hanford Site. This application is intended to cover existing cooling water and condensate discharges as well as similar future discharges meeting the criteria set forth in this document.

  15. Evaluation of thermal-storage concepts for solar cooling applications

    NASA Astrophysics Data System (ADS)

    Hughes, P. J.; Morehouse, J. H.; Choi, M. K.; White, N. M.; Scholten, W. B.

    1981-10-01

    Various configuration concepts for utilizing thermal energy storage to improve the thermal and economic performance of solar cooling systems for buildings were analyzed. The storge concepts evaluated provide short-term thermal storge via the bulk containment of water or salt hydrates. The evaluations were made for both residential-size cooling systems (3-ton) and small commercial-size cooling systems (25-ton). The residential analysis considers energy requirements for space heating, space cooling and water heating, while the commercial building analysis is based only on energy requirements for space cooling. The commercial building analysis considered a total of 10 different thermal storage/solar systems, 5 each for absorption and Rankine chiller concepts. The residential analysis considered 4 thermal storage/solar systems, all utilizing an absorption chiller. The trade-offs considered include: cold-side versus hot-side storage, single vs multiple stage storage, and phase-change vs sensible heat storage.

  16. Solid oxide fuel cell application in district cooling

    NASA Astrophysics Data System (ADS)

    Al-Qattan, Ayman; ElSherbini, Abdelrahman; Al-Ajmi, Kholoud

    2014-07-01

    This paper presents analysis of the performance of a combined cooling and power (CCP) system for district cooling. The cogeneration system is designed to provide cooling for a low-rise residential district of 27,300 RT (96 MWc). A solid oxide fuel cell (SOFC) generates electric power to operate chillers, and the exhaust fuel and heat from the SOFC run gas turbines and absorption chillers. Thermal energy storage is utilized to reduce system capacity. Part-load operation strategies target maximizing energy efficiency. The operation of the system is compared through an hourly simulation to that of packaged air-conditioning units typically used to cool homes. The CCP system with the district cooling arrangement improves the cooling-to-fuel efficiency by 346%. The peak power requirement is reduced by 57% (24 MW) and the total fuel energy is reduced by 54% (750 TJ y-1). The system cuts annual carbon dioxide emissions to less than half and reduces other harmful emissions. A cost analysis of the system components and operation resulted in a 53% reduction in the cost per ton-hour of cooling over traditional systems.

  17. New developments in caloric materials for cooling applications

    NASA Astrophysics Data System (ADS)

    Crossley, S.; Mathur, N. D.; Moya, X.

    2015-06-01

    Caloric materials are in the spotlight as candidates for future environmentally friendly cooling technologies. We describe stimulating recent developments in the three caloric strands that are now being studied collectively, namely magnetocaloric, electrocaloric and mechanocaloric (elastocaloric or barocaloric) effects.

  18. Low-cost Triangular Lattice Towers for Small Wind Turbines

    NASA Astrophysics Data System (ADS)

    Adhikari, Ram Chandra

    capacity or smaller. This study concludes that further work on joining of bamboo sections and weathering is required to fully utilize bamboo in practice. In comparison to steel towers, bamboo towers are economically feasible and easy to build. The tower is extremely lightweight, which justifies its application in remote areas, where the transportation is difficult.

  19. 43. TOP OF SOUTHEAST TOWER FROM SOUTH TOWER ROOF, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    43. TOP OF SOUTHEAST TOWER FROM SOUTH TOWER ROOF, LOOKING EAST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  20. 37. NORTH TOWER UPPER ZONE FROM SOUTH TOWER ROOF, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. NORTH TOWER UPPER ZONE FROM SOUTH TOWER ROOF, LOOKING NORTH - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  1. 19. NORTH TOWER, PORTE COCHERE & FLAG TOWER, LOOKING SOUTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. NORTH TOWER, PORTE COCHERE & FLAG TOWER, LOOKING SOUTHWEST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  2. 47. NORTHWEST TOWER FROM SOUTH TOWER ROOF, LOOKING NORTH BY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. NORTHWEST TOWER FROM SOUTH TOWER ROOF, LOOKING NORTH BY NORTHWEST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  3. 36. FLAG TOWER CLOCK ZONE FROM SOUTH TOWER ROOF, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. FLAG TOWER CLOCK ZONE FROM SOUTH TOWER ROOF, LOOKING NORTH - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  4. 40. CAMPANILE & SOUTHEAST TOWER FROM SOUTH TOWER ROOF, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. CAMPANILE & SOUTHEAST TOWER FROM SOUTH TOWER ROOF, LOOKING EAST BY NORTHEAST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  5. 18. NORTH TOWER, PORTE COCHERE & FLAG TOWER, LOOKING SOUTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. NORTH TOWER, PORTE COCHERE & FLAG TOWER, LOOKING SOUTHWEST BY WEST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  6. Thermal performance of phase change wallboard for residential cooling application

    SciTech Connect

    Feustel, H.E.; Stetiu, C.

    1997-04-01

    Cooling of residential California buildings contributes significantly to electrical consumption and peak power demand mainly due to very poor load factors in milder climates. Thermal mass can be utilized to reduce the peak-power demand, downsize the cooling systems, and/or switch to low-energy cooling sources. Large thermal storage devices have been used in the past to overcome the shortcomings of alternative cooling sources, or to avoid high demand charges. The manufacturing of phase change material (PCM) implemented in gypsum board, plaster or other wall-covering material, would permit the thermal storage to become part of the building structure. PCMs have two important advantages as storage media: they can offer an order-of-magnitude increase in thermal storage capacity, and their discharge is almost isothermal. This allows the storage of high amounts of energy without significantly changing the temperature of the room envelope. As heat storage takes place inside the building, where the loads occur, rather than externally, additional transport energy is not required. RADCOOL, a thermal building simulation program based on the finite difference approach, was used to numerically evaluate the latent storage performance of treated wallboard. Extended storage capacity obtained by using double PCM-wallboard is able to keep the room temperatures close to the upper comfort limits without using mechanical cooling. Simulation results for a living room with high internal loads and weather data for Sunnyvale, California, show significant reduction of room air temperature when heat can be stored in PCM-treated wallboards.

  7. CFD Model Development and validation for High Temperature Gas Cooled Reactor Cavity Cooling System (RCCS) Applications

    SciTech Connect

    Hassan, Yassin; Corradini, Michael; Tokuhiro, Akira; Wei, Thomas Y.C.

    2014-07-14

    The Reactor Cavity Cooling Systems (RCCS) is a passive safety system that will be incorporated in the VTHR design. The system was designed to remove the heat from the reactor cavity and maintain the temperature of structures and concrete walls under desired limits during normal operation (steady-state) and accident scenarios. A small scale (1:23) water-cooled experimental facility was scaled, designed, and constructed in order to study the complex thermohydraulic phenomena taking place in the RCCS during steady-state and transient conditions. The facility represents a portion of the reactor vessel with nine stainless steel coolant risers and utilizes water as coolant. The facility was equipped with instrumentation to measure temperatures and flow rates and a general verification was completed during the shakedown. A model of the experimental facility was prepared using RELAP5-3D and simulations were performed to validate the scaling procedure. The experimental data produced during the steady-state run were compared with the simulation results obtained using RELAP5-3D. The overall behavior of the facility met the expectations. The facility capabilities were confirmed to be very promising in performing additional experimental tests, including flow visualization, and produce data for code validation.

  8. Drop Tower Physics

    ERIC Educational Resources Information Center

    Dittrich, William A.

    2014-01-01

    The drop towers of yesteryear were used to make lead shot for muskets, as described in "The Physics Teacher" in April 2012. However, modern drop towers are essentially elevators designed so that the cable can "break" on demand, creating an environment with microgravity for a short period of time, currently up to nine seconds at…

  9. Confusion at the Tower

    ERIC Educational Resources Information Center

    Li, Loretta F.

    2014-01-01

    This study will explore the omission of the Tower of Babel narrative from middle and secondary school world history, world studies, and world geography textbooks and will consider what might be learned from inclusion of the story in the curriculum. A total of 17 textbooks are analyzed. The Tower of Babel narrative is examined within the context of…

  10. Structural active cooling applications for the Space Shuttle.

    NASA Technical Reports Server (NTRS)

    Masek, R. V.; Niblock, G. A.; Huneidi, F.

    1972-01-01

    Analytic and experimental studies have been conducted to evaluate a number of active cooling approaches to structural thermal protection for the Space Shuttle. The primary emphasis was directed toward the thermal protection system. Trade study results are presented for various heat shield material and TPS arrangements. Both metallic and reusable surface insulation (RSI) concepts were considered. Active systems heat sinks consisted of hydrogen, phase change materials, and expendable water. If consideration is given only to controlling the surface temperature, passive TPS was found to provide the most efficient system. Use of active cooling which incorporates some interior temperature control made the thermally less efficient RSI system more attractive.

  11. Wind tower service lift

    DOEpatents

    Oliphant, David; Quilter, Jared; Andersen, Todd; Conroy, Thomas

    2011-09-13

    An apparatus used for maintaining a wind tower structure wherein the wind tower structure may have a plurality of legs and may be configured to support a wind turbine above the ground in a better position to interface with winds. The lift structure may be configured for carrying objects and have a guide system and drive system for mechanically communicating with a primary cable, rail or other first elongate member attached to the wind tower structure. The drive system and guide system may transmit forces that move the lift relative to the cable and thereby relative to the wind tower structure. A control interface may be included for controlling the amount and direction of the power into the guide system and drive system thereby causing the guide system and drive system to move the lift relative to said first elongate member such that said lift moves relative to said wind tower structure.

  12. Long-term ice storage for cooling applications

    DOEpatents

    Schertz, William W.

    1981-01-01

    A device is providing for cooling a stored material and then for later use of the cold thus stored. The device includes a tank containing a liquid such as water which is frozen by means of a reflux condenser heat pipe.

  13. Long-term ice storage for cooling applications

    DOEpatents

    Schertz, W.W.

    A device is described for cooling a stored material and then for later use of the cold thus stored. The device includes a tank containing a liquid such as water which is frozen by means of a reflux condenser heat pipe.

  14. Drop Tower Physics

    NASA Astrophysics Data System (ADS)

    Dittrich, William A. Toby

    2014-10-01

    The drop towers of yesteryear were used to make lead shot for muskets, as described in The Physics Teacher1 in April 2012. However, modern drop towers are essentially elevators designed so that the cable can "break" on demand, creating an environment with microgravity for a short period of time, currently up to nine seconds at the drop tower in Bremen, Germany. Using these drop towers, one can briefly investigate various physical systems operating in this near zero-g environment. The resulting "Drop Tower Physics" is a new and exciting way to challenge students with a physical example that requires solid knowledge of many basic physics principles, and it forces them to practice the scientific method. The question is, "How would a simple toy, like a pendulum, behave when it is suddenly exposed to a zero-g environment?" The student must then postulate a particular behavior, test the hypothesis against physical principles, and if the hypothesis conforms to these chosen physical laws, the student can formulate a final conclusion. At that point having access to a drop tower is very convenient, in that the student can then experimentally test his or her conclusion. The purpose of this discussion is to explain the response of these physical systems ("toys") when the transition is made to a zero-g environment and to provide video demonstrations of this behavior to support in-class discussions of Drop Tower Physics.

  15. Extensible Wind Towers

    NASA Astrophysics Data System (ADS)

    Sinagra, Marco; Tucciarelli, Tullio

    The diffusion of wind energy generators is restricted by their strong landscape impact. The PERIMA project is about the development of an extensible wind tower able to support a wind machine for several hundred kW at its optimal working height, up to more than 50 m. The wind tower has a telescopic structure, made by several tubes located inside each other with their axis in vertical direction. The lifting force is given by a jack-up system confined inside a shaft, drilled below the ground level. In the retracted tower configuration, at rest, tower tubes are hidden in the foundation of the telescopic structure, located below the ground surface, and the wind machine is the only emerging part of the system. The lifting system is based on a couple of oleodynamic cylinders that jack-up a central tube connected to the top of the tower by a spring, with a diameter smaller than the minimum tower diameter and with a length a bit greater than the length of the extended telescopic structure. The central tube works as plunger and lifts all telescopic elements. The constraint between the telescopic elements is ensured by special parts, which are kept in traction by the force of the spring and provide the resisting moment. The most evident benefit of the proposed system is attained with the use of a two-blade propeller, which can be kept horizontal in the retracted tower configuration.

  16. High performance infrared fast cooled detectors for missile applications

    NASA Astrophysics Data System (ADS)

    Reibel, Yann; Espuno, Laurent; Taalat, Rachid; Sultan, Ahmad; Cassaigne, Pierre; Matallah, Noura

    2016-05-01

    SOFRADIR was selected in the late 90's for the production of 320×256 MW detectors for major European missile programs. This experience has established our company as a key player in the field of missile programs. SOFRADIR has since developed a vast portfolio of lightweight, compact and high performance JT-based solutions for missiles. ALTAN is a 384x288 Mid Wave infrared detector with 15μm pixel pitch, and is offered in a miniature ultra-fast Joule- Thomson cooled Dewar. Since Sofradir offers both Indium Antimonide (InSb) and Mercury Cadmium Telluride technologies (MCT), we are able to deliver the detectors best suited to customers' needs. In this paper we are discussing different figures of merit for very compact and innovative JT-cooled detectors and are highlighting the challenges for infrared detection technologies.

  17. Application of solar ponds to district heating and cooling

    NASA Astrophysics Data System (ADS)

    Leboeuf, C. M.

    1981-04-01

    A preliminary investigation is reported of the feasibility of incorporating solar ponds into subdivisions to provide district heating, domestic hot water (DHW), and district cooling. Two locations were chosen for analysis: Fort Worth, Texas and Washington, D.C. Solar ponds were sized to meet space heating, cooling, and DHW loads in each location for differing community sizes. Parameters such as storage layer temperature, pond geometry, and storage depth vs surface area were varied to determine the most effective approach to solar pond utilization. A distribution system for the district heating system was designed, including sizing of heat exchangers, piping, and pumps. Cost estimates for the pond and distribution system were formulated by using data generated in pond sizing, as well as associated system costs (e.g., salt costs and distribution system costs). Finally, solar ponds were found to be competitive with residential flat plate collector systems, with delivered energy costs as low as $16.00/GJ.

  18. Active Control of Jets in Cross-Flow for Film Cooling Applications

    NASA Technical Reports Server (NTRS)

    Nikitopoulos, Dimitris E.

    2003-01-01

    Jets in cross-flow have applications in film cooling of gas turbine vanes, blades and combustor liners. Their cooling effectiveness depends on the extent to which the cool jet-fluid adheres to the cooled component surface. Lift-off of the cooling jet flow or other mechanisms promoting mixing, cause loss of cooling effectiveness as they allow the hot "free-stream" fluid to come in contact with the component surface. The premise of this project is that cooling effectiveness can be improved by actively controlling (e.9. forcing, pulsing) the jet flow. Active control can be applied to prevent/delay lift-off and suppress mixing. Furthermore, an actively controlled film-cooling system coupled with appropriate sensory input (e.g. temperature or heat flux) can adapt to spatial and temporal variations of the hot-gas path. Thus, it is conceivable that the efficiency of film-cooling systems can be improved, resulting in coolant fluid economy. It is envisioned that Micro Electro-Mechanical Systems (MEMS) will play a role in the realization of such systems. As a first step, a feasibility study will be conducted to evaluate the concept, identify actuation and sensory elements and develop a control strategy. Part of this study will be the design of a proof-of-concept experiment and collection of necessary data.

  19. A Modified Cooling Method and Its Application in "Drosophila" Experiments

    ERIC Educational Resources Information Center

    Qu, Wen-hui; Zhu, Tong-bo; Yang, Da-Xiang

    2015-01-01

    Chilling is a cost-effective and safe method of immobilising flies in "Drosophila" experiments. However, should condensation form on the plate, it would be fatal to the flies. Here we describe a modified cooling method using reusable commercial ice pack(s) (ca. 400 ml, 2-3 cm tall) rather than crushed ice. The ice pack is covered with a…

  20. Tower Camera Handbook

    SciTech Connect

    Moudry, D

    2005-01-01

    The tower camera in Barrow provides hourly images of ground surrounding the tower. These images may be used to determine fractional snow cover as winter arrives, for comparison with the albedo that can be calculated from downward-looking radiometers, as well as some indication of present weather. Similarly, during spring time, the camera images show the changes in the ground albedo as the snow melts. The tower images are saved in hourly intervals. In addition, two other cameras, the skydeck camera in Barrow and the piling camera in Atqasuk, show the current conditions at those sites.

  1. DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER SIX WITH TOWERS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER SIX WITH TOWERS SEVEN,EIGHT, NINE, TEN, AND BREAK OVER TOWER IN DISTANCE, LOOKING NORTH. TOWER SIX IS THE LAST BEFORE A DEEP CHASM, AS IS SEEN BY THE DISTANCE BETWEEN TOWERS SIX AND SEVEN. SEE CA-291-48 (CT) FOR IDENTICAL COLOR TRANSPARENCY. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  2. DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER SIX WITH TOWERS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER SIX WITH TOWERS SEVEN, EIGHT, NINE, TEN, AND BREAK OVER TOWER IN DISTANCE, LOOKING NORTH. TOWER SIX IS THE LAST BEFORE A DEEP CHASM, AS IS SEEN BY THE DISTANCE BETWEEN TOWERS SIX AND SEVEN. SEE CA-291-21 FOR IDENTICAL B&W NEGATIVE. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  3. Aquarius: Tower Rollback

    NASA Video Gallery

    The mobile service tower at NASA's Launch Complex-2 at Vandenberg Air Force Base in California is being moved away from the ULA Delta II rocket with the Aquarius/SAC-D spacecraft atop, in preparati...

  4. (Thermal energy storage technologies for heating and cooling applications)

    SciTech Connect

    Tomlinson, J.J.

    1990-12-19

    Recent results from selected TES research activities in Germany and Sweden under an associated IEA annex are discussed. In addition, several new technologies for heating and cooling of buildings and automobiles were reviewed and found to benefit similar efforts in the United states. Details of a meeting with Didier-Werke AG, a leading German ceramics manufacturer who will provide TES media necessary for the United States to complete field tests of an advanced high temperature latent heat storage material, are presented. Finally, an overview of the December 1990 IEA Executive Committee deliberations on TES is presented.

  5. EFFECTS OF PATHOGENIC AND TOXIC MATERIALS TRANSPORTED VIA COOLING DEVICE DRIFT - VOLUME 1. TECHNICAL REPORT

    EPA Science Inventory

    The report describes a mathematical model that predicts the percent of the population affected by a pathogen or toxic substance emitted in a cooling tower plume, and gives specific applications of the model. Eighty-five pathogens (or diseases) are cataloged as potentially occurri...

  6. EFFECTS OF PATHOGENIC AND TOXIC MATERIALS TRANSPORTED VIA COOLING DEVICE DRIFT. VOLUME 2. APPENDICES

    EPA Science Inventory

    The report describes a mathematical model that predicts the percent of the population affected by a pathogen or toxic substance emitted in a cooling tower plume, and gives specific applications of the model. Eighty-five pathogens (or diseases) are cataloged as potentially occurri...

  7. Drop Tower Workshop

    NASA Technical Reports Server (NTRS)

    Urban, David

    2013-01-01

    Ground based microgravity facilities are an important proving ground for space experiments, ground-based research and space hardware risk mitigation. An overview of existing platforms will be discussed with an emphasis on drop tower capabilities. The potential for extension to partial gravity conditions will be discussed. Input will be solicited from attendees for their potential to use drop towers in the future and the need for enhanced capabilities (e.g. partial gravity)

  8. Novel Applications of Buffer-gas Cooling to Cold Atoms, Diatomic Molecules, and Large Molecules

    NASA Astrophysics Data System (ADS)

    Drayna, Garrett Korda

    Cold gases of atoms and molecules provide a system for the exploration of a diverse set of physical phenomena. For example, cold gasses of magnetically and electrically polar atoms and molecules are ideal systems for quantum simulation and quantum computation experiments, and cold gasses of large polar molecules allow for novel spectroscopic techniques. Buffer-gas cooling is a robust and widely applicable method for cooling atoms and molecules to temperatures of approximately 1 Kelvin. In this thesis, I present novel applications of buffer-gas cooling to obtaining gases of trapped, ultracold atoms and diatomic molecules, as well as the study of the cooling of large organic molecules. In the first experiment of this thesis, a buffer-gas beam source of atoms is used to directly load a magneto-optical trap. Due to the versatility of the buffer-gas beam source, we obtain trapped, sub-milliKelvin gases of four different lanthanide species using the same experimental apparatus. In the second experiment of this thesis, a buffer-gas beam is used as the initial stage of an experiment to directly laser cool and magneto-optically trap the diatomic molecule CaF. In the third experiment of this thesis, buffer-gas cooling is used to study the cooling of the conformational state of large organic molecules. We directly observe conformational relaxation of gas-phase 1,2-propanediol due to cold collisions with helium gas. Lastly, I present preliminary results on a variety of novel applications of buffer-gas cooling, such as mixture analysis, separation of chiral mixtures, the measurement of parity-violation in chiral molecules, and the cooling and spectroscopy of highly unstable reaction intermediates.

  9. Steam-Electric Power-Plant-Cooling Handbook

    SciTech Connect

    Sonnichsen, J.C.; Carlson, H.A.; Charles, P.D.; Jacobson, L.D.; Tadlock, L.A.

    1982-02-01

    The Steam-Electric Power Plant Cooling Handbook provides summary data on steam-electric power plant capacity, generation and number of plants for each cooling means, by Electric Regions, Water Resource Regions and National Electric Reliability Council Areas. Water consumption by once-through cooling, cooling ponds and wet evaporative towers is discussed and a methodology for computation of water consumption is provided for a typical steam-electric plant which uses a wet evaporative tower or cooling pond for cooling.

  10. The numerical model of biosorption of Zn2+ and its application to the bio-electro tower reactor (BETR).

    PubMed

    Wang, Tao; Wang, Hui; Li, Chunqing; Liu, Bo-Tan

    2016-03-01

    A 2-D numerical kinetic model considering flow velocity and adsorption is developed to simulate the bio-electro tower reactor (BETR). This new model considers the adsorbed amount when equilibrium qe as transient variable, which is superior to the old pseudo-first-order and the pseudo-second-order model which regards qe as a constant. We did research on the intensifying effect of electric field upon heavy metal ions adsorption process. The calculation result matches well with the experimental data. BETR is a coupling technique whose mechanism is that outer electric field can enhance the mass transfer rate when the solute is metal ions. Two kinds of carriers, pottery ball and 3-dimensional electrode (3DE), were used to support the biofilm layer; and organic wastewater that contains Zn(2+) is selected as a sample to validate the model. The 3DE carriers can be polarized by outer electric field, but pottery ball cannot. It is found that Zn(2+) transfers faster in 3DE carriers than in pottery ball (insulation materials); and an intensifying coefficientη is introduced to describe this effect in BETR. PMID:26735722

  11. Passive coolers for pre-cooling of JT loops for deep space infrared imaging applications

    NASA Astrophysics Data System (ADS)

    Zhang, Burt; Larson, Melora; Rodriguez, Jose

    2010-09-01

    Infrared instruments (IR) for deep space imaging missions, such as the James Webb Space Telescope (JWST) and Planck, require cryogenic cooling for proper operation of their focal plane arrays (FPA) in far infrared and sub-millimeter wavelength ranges. The FPA is sometimes located meters away from the spacecraft. To meet such remote cooling requirement, a Joule-Thomson (J-T) loop becomes a convenient choice for either direct cooling for the FPA or for serving as a heat sink for a cascade cooling system. The refrigerant lines of the JT loop inevitably suffer parasitic heat leak primarily due to IR backload as they traverse from the spacecraft to the FPA. An actively cooled JT loop using a mechanical pre-cooler located at the spacecraft will experience the highest parasitic heat leak since the lines are cold through the entire length whereas a passively cooled JT loop can utilize a number of radiators to cool the lines down gradually in stages and hence reduce the heat leak. In addition to savings in power and mass, a passive cooler offers consistent and predictable performance with practically no performance degradation in a thermally stable orbit, such as one around the Sun-Earth L2 point. Passive coolers are less popular in low temperature applications when their cooling capacity diminishes rapidly in proportion to T4 until the temperature reaches a point where either the parasitic heat leak becomes so significant or its size becomes so excessive that the passive cooling scheme becomes impractical. Despite the limited capacity, passive cooling may still prove to be a viable alternative to active cooling depending on the operating temperature and heat dissipation rate of the FPA. The current effort aims at evaluating the merit of using passive coolers as an alternative to using a mechanical cooler for pre-cooling of a JT loop for remote IR instrument cooling. A parametric study is conducted to explore the merits of passive cooling of a JT loop in a temperature range

  12. Radiation thermodynamics with applications to lasing and fluorescent cooling

    NASA Astrophysics Data System (ADS)

    Mungan, Carl E.

    2005-04-01

    Laser cooling of bulk matter uses thermally assisted fluorescence to convert heat into light and can be interpreted as an optically pumped laser running in reverse. Optical pumping in such devices drives the level populations out of equilibrium. Nonthermal radiative energy transfers are thereby central to the operation of both lasers and luminescent coolers. A thermodynamic treatment of their limiting efficiencies requires a careful development of the entropy and effective temperatures of radiation, valid for the entire range of light from the blackbody to the ideal laser limiting cases. In particular, the distinct meaning and utility of the brightness and flux temperatures should be borne in mind. Numerical examples help illustrate these concepts at a level suitable for undergraduate physics majors.

  13. Nano-PCMs for passive electronic cooling applications

    NASA Astrophysics Data System (ADS)

    Colla, L.; Fedele, L.; Mancin, S.; Buonomo, B.; Ercole, D.; Manca, O.

    2015-11-01

    The present work aims at investigating a new challenging use of oxide (TiO2, Al2O3, etc.) nanoparticles to enhance the thermal properties: thermal conductivity, specific heat, and latent heat of pure paraffin waxes to obtain a new class of Phase Change Materials (PCMs), the so-called nano-PCMs. The nano-PCMs were obtained by seeding different amounts of oxide nanoparticles in a paraffin wax having a melting temperature of 45°C. The thermophysical properties such as latent heat and thermal conductivity were then measured to understand the effects of the nanoparticles on the thermal properties of both the solid and liquid PCM. Finally, a numerical comparison between the use of the pure paraffin wax and the nano-PCM in a typical electronics passive cooling device was implemented. Numerical simulations were carried out using the Ansys-Fluent 15.0 code. Results in terms of solid and liquid phase temperatures, melting time and junction temperature were reported. Moreover, a comparison with experimental results was also performed.

  14. DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER TWO, WITH TOWERS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF AERIAL TRAM SUPPORT TOWER TWO, WITH TOWERS THREE,FOUR, FIVE AND SIX IN DISTANCE, LOOKING NORTHEAST. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  15. 46. OCTAGONAL & WEST TOWERS FROM SOUTH TOWER ROOF, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    46. OCTAGONAL & WEST TOWERS FROM SOUTH TOWER ROOF, LOOKING NORTHWEST, WITH WEST WING ROOF - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  16. 42. SOUTHEAST TOWER & EAST WING ROOF FROM SOUTH TOWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. SOUTHEAST TOWER & EAST WING ROOF FROM SOUTH TOWER ROOF, LOOKING EAST BY NORTHEAST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  17. 41. SOUTHEAST TOWER & EAST WING FROM SOUTH TOWER ROOF, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. SOUTHEAST TOWER & EAST WING FROM SOUTH TOWER ROOF, LOOKING EAST BY NORTHEAST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  18. View of the north tower porte cochere and flag tower, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of the north tower porte cochere and flag tower, looking southwest (duplicate of HABS No. DC-141-19) - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  19. 45. OCTAGONAL, WEST & NORTHWEST TOWERS FROM SOUTH TOWER ROOF, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. OCTAGONAL, WEST & NORTHWEST TOWERS FROM SOUTH TOWER ROOF, LOOKING WEST BY NORTHWEST - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  20. 3. VIEW NORTHWEST, height finder radar towers, and radar tower ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW NORTHWEST, height finder radar towers, and radar tower (unknown function) - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  1. 8. GENERAL VIEW OF TOWER 32, LEFT, AND TOWER 31, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. GENERAL VIEW OF TOWER 32, LEFT, AND TOWER 31, RIGHT. VIEW LOOKING NORTH SHOWING AERIAL WIRE DESIGN WITH VERTICAL 'TOP HAT' WIRES IN CENTER. - Chollas Heights Naval Radio Transmitting Facility, 6410 Zero Road, San Diego, San Diego County, CA

  2. 69. INTERIOR VIEW OF THE ABSORPTION TOWER BUILDING, ABSORPTION TOWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    69. INTERIOR VIEW OF THE ABSORPTION TOWER BUILDING, ABSORPTION TOWER UNDER CONSTRUCTION. (DATE UNKNOWN). - United States Nitrate Plant No. 2, Reservation Road, Muscle Shoals, Muscle Shoals, Colbert County, AL

  3. Solar power towers

    SciTech Connect

    Not Available

    1998-04-01

    The high desert near Barstow, California, has witnessed the development of this country`s first two solar power towers. Solar One operated successfully from 1982 to 1988 and proved that power towers work efficiently to produce utility-scale power from sunlight. Solar Two was connected to the utility grid in 1996 and is operating today. Like its predecessor, Solar Two is rated at 10 megawatts. An upgrade of the Solar One plant, Solar Two demonstrates how solar energy can be stored in the form of heat in molten salt for power generation on demand. The experience gained with these two pilot power towers has established a foundation on which industry can develop its first commercial plants. These systems produce electricity on a large scale. They are unique among solar technologies because they can store energy efficiently and cost effectively. They can operate whenever the customer needs power, even after dark or during cloudy weather.

  4. THE TOWER HOUSE, LOOKING WEST. The tower house provided a ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    THE TOWER HOUSE, LOOKING WEST. The tower house provided a water tank on the second floor that gravity fed water to the Kineth house and farm buildings. The one-story addition to the west of the tower provided workshop space. The hog shed is seen on the left of the image and the concrete foundation of the upright silo is in the foreground on the right. - Kineth Farm, Tower House, 19162 State Route 20, Coupeville, Island County, WA

  5. 47 CFR 5.109 - Antenna and tower requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Antenna and tower requirements. 5.109 Section 5... BROADCAST) Technical Standards and Operating Requirements § 5.109 Antenna and tower requirements. (a) Applicants with fixed stations that use antennas that exceed 6 meters in height above the ground level...

  6. 47 CFR 5.109 - Antenna and tower requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Antenna and tower requirements. 5.109 Section 5... BROADCAST) Technical Standards and Operating Requirements § 5.109 Antenna and tower requirements. (a) Applicants with fixed stations that use antennas that exceed 6 meters in height above the ground level...

  7. 47 CFR 5.109 - Antenna and tower requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Antenna and tower requirements. 5.109 Section 5... BROADCAST) Technical Standards and Operating Requirements § 5.109 Antenna and tower requirements. (a) Applicants with fixed stations that use antennas that exceed 6 meters in height above the ground level...

  8. Applications of heat pipes to cool PWBS and hybrid microcircuits

    NASA Technical Reports Server (NTRS)

    Sekhon, K. S.

    1986-01-01

    Some of the advanced thermal management techniques used to reduce operating junction temperature under extreme environmental temperature conditions are discussed. Heat pipes in actual electronic packaging applications, and those under development, are discussed. Performance characteristics of heat pipes are given, and examples are described of how thermal problems in electronic packaging are solved through the use of heat pipes.

  9. 5. VIEW EAST, height finder radar towers, radar tower (unknown ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. VIEW EAST, height finder radar towers, radar tower (unknown function), prime search radar tower, operations building, and central heating plant - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  10. Testing of novel desiccant materials and dehumidifier matrices for desiccant cooling applications

    SciTech Connect

    Pesaran, A.A.; Bingham, C.E.

    1989-03-01

    This paper presents the results of testing of desiccant materials and dehumidifier matrices for desiccant cooling and dehumidification applications. In testing desiccant materials, we used a gravimetric technique to measure the moisture capacity of four desiccant materials. These materials were microporous silica gel powder, macroporous silica gel powder, polystyrene sulfonic acid sodium salt, and a silica-gel/epoxy composite. The microporous silica gel powder had the most desirable moisture capacity properties of the four materials tested for desiccant cooling applications. The polystyrene sulfonic acid sodium salt showed some promise. Our testing of dehumidifier matrices included measuring the pressure drop and heat- and mass-transfer rate characteristics of a silica-gel/corrugated dehumidifier matrix under conditions typical of desiccant cooling systems. The matrix is a section of a commercial dehumidifier. The transient dehumidification capacity of the matrix was calculated from the tests and compared with previously tested matrices. 9 refs., 10 figs., 2 tabs.

  11. Novel Magnetic Materials for Sensing and Cooling Applications

    NASA Astrophysics Data System (ADS)

    Chaturvedi, Anurag

    2011-12-01

    The overall goals of the present PhD research are to explore the giant magnetoimpedance (GMI) and giant magnetocaloric (GMC) effects in functional magnetic materials and provide guidance on the optimization of the material properties for use in advanced magnetic sensor and refrigeration applications. GMI has attracted growing interest due to its promising applications in high-performance magnetic sensors. Research in this field is focused on the development of new materials with properties appropriate for practical GMI sensor applications. In this project, we have successfully set up a new magneto-impedance measurement system in the Functional Materials Laboratory at USF. We have established, for the first time, the correlation between sample surface, magnetic softness, critical length, and GMI in Co-based amorphous ribbon materials, which provide a good handle on selecting the suitable operating frequency range of magnetic materials for GMI-based field sensor applications. The impact of field-induced magnetic anisotropy on the GMI effect in Co-based nanocrystalline ribbon materials has also been investigated, providing an important understanding of the correlation between the microstructure, magnetic anisotropy, and GMI in these materials. We have shown that coating a thin layer of magnetic metal on the surface of a magnetic ribbon can reduce stray fields due to surface irregularities and enhance the magnetic flux paths closure of the bilayer structure, both of which, in effect, increase the GMI and its field sensitivity. This finding provides a new way for tailoring GMI in surface-modified soft ferromagnetic ribbons for use in highly sensitive magnetic sensors. We have also introduced the new concepts of incorporating GMI technology with superparamagnetic nanoparticles for biosensing applications and with carbon nanotubes for gas and chemical sensing applications. GMC forms the basis for developing advanced magnetic refrigeration technology and research in this

  12. Ivory Basements and Ivory Towers

    ERIC Educational Resources Information Center

    Fitzgerald, Tanya

    2012-01-01

    The metaphors of the ivory tower and ivory basement are used in this chapter to reflect how many women understand and experience the academy. The ivory tower signifies a place that is protected, a place of privilege and authority and a place removed from the outside world (and consequently the rigours of the market place). The ivory tower, by…

  13. 40 CFR 463.10 - Applicability; description of the contact cooling and heating water subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Applicability; description of the contact cooling and heating water subcategory. 463.10 Section 463.10 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PLASTICS MOLDING AND FORMING POINT SOURCE CATEGORY Contact...

  14. Key technologies and applications of laser cooling and trapping 87Rb atomic system

    NASA Astrophysics Data System (ADS)

    Ru, Ning; Zhang, Li; Wang, Yu; Fan, Shangchun

    2016-06-01

    Atom Interferometry is proved to be a potential method for measuring the acceleration of atoms due to Gravity, we are now building a feasible system of cold atom gravimeter. In this paper development and the important applications of laser cooling and trapping atoms are introduced, some key techniques which are used to obtain 87Rb cold atoms in our experiments are also discussed.

  15. Spectroscopic Characterization of Thulium doped Potassium Lead Chloride for Potential Applications in Optical Cooling

    NASA Astrophysics Data System (ADS)

    Brown, Ei; Brown, Herbert; Hommerich, Uwe; Bluiett, Althea; Trivedi, Sudhir

    2013-03-01

    Rare-earth doped solids have experienced increased attention for possible applications in anti-Stokes fluorescence cooling. Solid-state optical refrigeration offer several advantages over current bulky mechanical coolers including compact, lightweight, and vibration free. Most efforts have focused on optical cooling in Yb3+ doped solids and cooling down to ~155 K has been demonstrated. In this work, the optical properties of Tm3+ doped KPC were evaluated as a potential solid-state material for laser cooling applications. Following 1907 nm excitation, Tm:KPC exhibited infrared emission with a center wavelength of 1806 nm arising from the 3F4 --> 3H6 transition of Tm3+ ions. Under 1907nm pumping conditions, it was estimated that a quantum emission efficiency of at least 95% is required to achieve a net cooling effect in Tm:KPC. Based on temperature dependent decay time studies the emission quantum efficiency of Tm:KPC was estimated to be only ~75%. Employing the energy-gap law, non-radiative decay through multi-phonon relaxation is predicted to be negligibly small in Tm:KPC. Concentration quenching effects and/or energy transfer processes to other defects seems most likely to be responsible for the low quantum efficiency.

  16. A review of gas-cooled reactor concepts for SDI (Strategic Defense Initiative) applications

    SciTech Connect

    Marshall, A.C.

    1989-08-01

    We have completed a review of multimegawatt gas-cooled reactor concepts proposed for SDI applications. Our study concluded that the principal reason for considering gas-cooled reactors for burst-mode operation was the potential for significant system mass savings over closed-cycle systems if open-cycle gas-cooled operation (effluent exhausted to space) is acceptable. The principal reason for considering gas-cooled reactors for steady-state operation is that they may represent a lower technology risk than other approaches. In the review, nine gas-cooled reactor concepts were compared to identify the most promising. For burst-mode operation, the NERVA (Nuclear Engine for Rocket Vehicle Application) derivative reactor concept emerged as a strong first choice since its performance exceeds the anticipated operational requirements and the technology has been demonstrated and is retrievable. Although the NERVA derivative concepts were determined to be the lead candidates for the Multimegawatt Steady-State (MMWSS) mode as well, their lead over the other candidates is not as great as for the burst mode. 90 refs., 2 figs., 10 tabs.

  17. Cell Towers and Songbirds

    ERIC Educational Resources Information Center

    Klosterman, Michelle; Mesa, Jennifer; Milton, Katie

    2009-01-01

    This article describes how our common addiction to cell phones was used to launch a discussion about their use, impacts on the environment, and connections to issues of civic concern. By encouraging middle school science students to adopt the perspectives of special-interest groups debating communication tower restrictions designed to protect…

  18. Talking Towers, Making Withs.

    ERIC Educational Resources Information Center

    Lemke, J. L.

    The notion of a linguistic "register" is useful in posing questions about how the ways language is used differ from one kind of human activity to another. This paper analyzes a videotaped segment of male grade 4/5 students (n=3) who are talking as they work to build a tower from plastic drinking straws and pins. Discussion of the analysis…

  19. The Ivory Tower Revisited

    ERIC Educational Resources Information Center

    Chantler, Abigail

    2016-01-01

    The corollary of the concept of the "ivory tower", as reflected in the writings of Plato and Newman amongst others, was, paradoxically, the vital importance of the university for wider society. Nevertheless from the mid-twentieth century, the esteem in which a "liberal" university education was held was diminished by rising…

  20. The Prospects of Alternatives to Vapor Compression Technology for Space Cooling and Food Refrigeration Applications

    SciTech Connect

    Brown, Daryl R.; Stout, Tyson E.; Dirks, James A.; Fernandez, Nicholas

    2012-12-01

    This article identifies and describes five alternative cooling technologies (magnetic, thermionic, thermoacoustic, thermoelectric, and thermotunnel) and qualitatively assesses the prospects of each technology relative to vapor compression for space cooling and food refrigeration applications. Assessment of the alternatives was based on the theoretical maximum % of Carnot efficiency, the current state of development, the best % of Carnot efficiency currently achieved, developmental barriers, and the extent of development activity. The prospect for each alternative was assigned an overall qualitative rating based on the subjective, composite view of the five characteristics.

  1. Thermostructural applications of heat pipes for cooling leading edges of high-speed aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Camarda, Charles J.; Glass, David E.

    1992-01-01

    Heat pipes have been considered for use on wing leading edge for over 20 years. Early concepts envisioned metal heat pipes cooling a metallic leading edge. Several superalloy/sodium heat pipes were fabricated and successfully tested for wing leading edge cooling. Results of radiant heat and aerothermal testing indicate the feasibility of using heat pipes to cool the stagnation region of shuttle-type space transportation systems. The test model withstood a total seven radiant heating tests, eight aerothermal tests, and twenty-seven supplemental radiant heating tests. Cold-wall heating rates ranged from 21 to 57 Btu/sq ft-s and maximum operating temperatures ranged from 1090 to 1520 F. Follow-on studies investigated the application of heat pipes to cool the stagnation regions of single-stage-to-orbit and advanced shuttle vehicles. Results of those studies indicate that a 'D-shaped' structural design can reduce the mass of the heat-pipe concept by over 44 percent compared to a circular heat-pipe geometry. Simple analytical models for heat-pipe startup from the frozen state (working fluid initially frozen) were adequate to approximate transient, startup, and steady-state heat-pipe performance. Improvement in analysis methods has resulted in the development of a finite-element analysis technique to predict heat-pipe startup from the frozen state. However, current requirements of light-weight design and reliability suggest that metallic heat pipes embedded in a refractory composite material should be used. This concept is the concept presently being evaluated for NASP. A refractory-composite/heat-pipe-cooled wing leading edge is currently being considered for the National Aero-Space Plane (NASP). This concept uses high-temperature refractory-metal/lithium heat pipes embedded within a refractory-composite structure and is significantly lighter than an actively cooled wing leading edge because it eliminates the need for active cooling during ascent and descent. Since the

  2. Survey of Cooling Options for Application in a Low-TC Squid System for Fetal Magnetocardiography

    NASA Astrophysics Data System (ADS)

    Rijpma, A. P.; Uzunbajakau, S.; ter Brake, H. J. M.; Peters, M. J.; Rogalla, H.

    2004-06-01

    As part of the development of a low-Tc SQUID-based magnetometer system for measuring fetal heart activity, the means of cooling is evaluated. To lower the threshold for the clinical application of this fetal heart monitor, it should be simple to operate. It is, therefore, deemed necessary to replace the liquid helium by a closed-cycle refrigerator. In this paper, the requirements with respect to the cryogenic system are defined. These include operating temperature (4 K), temperature stability (<0.2 K), cooling power (>0.1 W) and requirements on magnetic and mechanical interference. The paper also reviews the most relevant options for the realization of the cryogenic system. After comparison, we selected a 4-K mechanical cooler. To reduce the interference, it is placed at several meters from the magnetometer. The cooling power is to be transferred by circulation of helium.

  3. Present status of developments in physical sorption cooling for space applications

    NASA Astrophysics Data System (ADS)

    Benthem, B.; Doornink, J.; Boom, E.; Holland, H. J.; Lerou, P. P. P. M.; Burger, J. F.; ter Brake, H. J. M.

    2014-11-01

    A sorption cooler uses the Joule-Thomson effect for cooling a gas by expanding it through a flow restriction. The flow of gas is sustained by a compressor consisting of one or more sorption cells, which cyclically adsorb and desorb gas according to the fully reversible process of physical sorption. The technology has been shown to provide active cooling in the cryogenic temperature range without exporting vibrations or electromagnetic interference. Due to full reversibility of the process and the absence of moving parts (apart from check valves, which open and close with a very low frequency), such a cooler has the potential for a very long life and high reliability. This paper starts with a recapitulation of the principles of physical sorption cooling followed by an overview of the strengths and weaknesses of the technology in relation to other space cooling technologies, such as pulse-tube cooling and Stirling cooling. Next, the present status of physical sorption cooling technology is presented based on developments previously and currently being performed by the University of Twente, Dutch Space and Kryoz Technologies. A summary will be given of the various existing demonstrator- and lab-models which have been built, along with an overview of the tests which have so far been performed. The central result of this paper is an assessment of the current Technology Readiness Level (TRL) of various sorption cooler configurations, along with their application range in terms of temperatures, heat loads and mission profile. Finally, an outline is given on the way forward currently being pursued by the developers to achieve full maturity of the technology.

  4. Drop Tower Facility at Queensland University of Technology

    NASA Astrophysics Data System (ADS)

    Plagens, Owen; Castillo, Martin; Steinberg, Theodore; Ong, Teng-Cheong

    The Queensland University of Technology (QUT) Drop Tower Facility is a {raise.17exscriptstyle˜}2.1 second, 21.3 m fall, dual capsule drop tower system. The dual capsule comprises of an uncoupled exterior hollow drag shield that experiences drag by the ambient atmosphere with the experimental capsule falling within the drag shield. The dual capsule system is lifted to the top of the drop tower via a mechanical crane and the dropping process is initiated by the cutting of a wire coupling the experimental package and suspending the drag shield. The internal experimental capsule reaches the bottom of the drag shield floor just prior to the deceleration stage at the air bag and during this time experience gravity levels of {raise.17exscriptstyle˜}10textsuperscript{-6} g. The deceleration system utilizes an inflatable airbag where experimental packages can be designed to experience a maximum deceleration of {raise.17exscriptstyle˜}10textsuperscript{18} g for {raise.17exscriptstyle˜}0.1 seconds. The drag shield can house experimental packages with a maximum diameter of 0.8 m and height of 0.9 m. The drag shield can also be used in foam mode, where the walls are lined with foam and small experiments can be dropped completely untethered. This mode is generally used for the study of microsatellite manipulation. Payloads can be powered by on-board power systems with power delivered to the experiment until free fall occurs. Experimental data that can be collected includes but is not limited to video, temperature, pressure, voltage/current from the power supply, and triggering mechanisms outputs which are simultaneously collected via data logging systems and high speed video recording systems. Academic and commercial projects are currently under investigation at the QUT Drop Tower Facility and collaboration is openly welcome at this facility. Current research includes the study of heterogeneously burning metals in oxygen which is aimed at fire safety applications and

  5. Feasibility of Actively Cooled Silicon Nitride Airfoil for Turbine Applications Demonstrated

    NASA Technical Reports Server (NTRS)

    Bhatt, Ramakrishna T.

    2001-01-01

    Nickel-base superalloys currently limit gas turbine engine performance. Active cooling has extended the temperature range of service of nickel-base superalloys in current gas turbine engines, but the margin for further improvement appears modest. Therefore, significant advancements in materials technology are needed to raise turbine inlet temperatures above 2400 F to increase engine specific thrust and operating efficiency. Because of their low density and high-temperature strength and thermal conductivity, in situ toughened silicon nitride ceramics have received a great deal of attention for cooled structures. However, the high processing costs and low impact resistance of silicon nitride ceramics have proven to be major obstacles for widespread applications. Advanced rapid prototyping technology in combination with conventional gel casting and sintering can reduce high processing costs and may offer an affordable manufacturing approach. Researchers at the NASA Glenn Research Center, in cooperation with a local university and an aerospace company, are developing actively cooled and functionally graded ceramic structures. The objective of this program is to develop cost-effective manufacturing technology and experimental and analytical capabilities for environmentally stable, aerodynamically efficient, foreign-object-damage-resistant, in situ toughened silicon nitride turbine nozzle vanes, and to test these vanes under simulated engine conditions. Starting with computer aided design (CAD) files of an airfoil and a flat plate with internal cooling passages, the permanent and removable mold components for gel casting ceramic slips were made by stereolithography and Sanders machines, respectively. The gel-cast part was dried and sintered to final shape. Several in situ toughened silicon nitride generic airfoils with internal cooling passages have been fabricated. The uncoated and thermal barrier coated airfoils and flat plates were burner rig tested for 30 min without

  6. Miniature and cooled hyperspectral camera for outdoor surveillance applications in the mid-infrared.

    PubMed

    Fossi, Armande Pola; Ferrec, Yann; Roux, Nicolas; D'almeida, Oscar; Guerineau, Nicolas; Sauer, Hervé

    2016-05-01

    We present the design and the realization of a compact and robust imaging spectrometer in the mid-infrared spectral range. This camera combines a small static Fourier transform birefringent interferometer and a cooled miniaturized infrared camera in order to build a robust and compact instrument that can be embedded in an unmanned aerial vehicle for hyperspectral imaging applications. This instrument has been tested during a gas detection measurement campaign. First results are presented. PMID:27128034

  7. The Prospects of Alternatives to Vapor Compression Technology for Space Cooling and Food Refrigeration Applications

    SciTech Connect

    Brown, Daryl R.; Dirks, James A.; Fernandez, Nicholas; Stout, Tyson E.

    2010-03-31

    Five alternatives to vapor compression technology were qualitatively evaluated to determine their prospects for being better than vapor compression for space cooling and food refrigeration applications. The results of the assessment are summarized in the report. Overall, thermoacoustic and magnetic technologies were judged to have the best prospects for competing with vapor compression technology, with thermotunneling, thermoelectric, and thermionic technologies trailing behind in that order.

  8. Towers of hybrid mesons

    SciTech Connect

    Semay, Claude; Buisseret, Fabien; Silvestre-Brac, Bernard

    2009-05-01

    A hybrid meson is a quark-antiquark pair in which, contrary to ordinary mesons, the gluon field is in an excited state. In the framework of constituent models, the interaction potential is assumed to be the energy of an excited string. An approximate, but accurate, analytical solution of the Schroedinger equation with such a potential is presented. When applied to hybrid charmonia and bottomonia, towers of states are predicted in which the masses are a linear function of a harmonic oscillator band number for the quark-antiquark pair. Such a formula could be a reliable guide for the experimental detection of heavy hybrid mesons.

  9. 2. Southern Light Tower and Northern Light Tower, view north, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Southern Light Tower and Northern Light Tower, view north, south sides - Kennebec River Light Station, South side of Doubling Point Road, off State Highway 127, 1.8 miles south of U.S. Route 1, Arrowsic, Sagadahoc County, ME

  10. Flow visualization of discrete hole film cooling for gas turbine applications

    NASA Technical Reports Server (NTRS)

    Colladay, R. S.; Russell, L. M.

    1975-01-01

    Film injection from discrete holes in a three row staggered array with 5-diameter spacing is studied. The boundary layer thickness-to-hole diameter ratio and Reynolds number are typical of gas turbine film cooling applications. Two different injection locations are studied to evaluate the effect of boundary layer thickness on film penetration and mixing. Detailed streaklines showing the turbulent motion of the injected air are obtained by photographing neutrally buoyant helium filled soap bubbles which follow the flow field. The bubble streaklines passing downstream injection locations are clearly identifiable and can be traced back to their origin. Visualization of surface temperature patterns obtained from infrared photographs of a similar film cooled surface are also included.

  11. Experimental investigation of Demon-like Algorithmic Quantum Cooling and its Applications

    NASA Astrophysics Data System (ADS)

    Li, Chuan-Feng

    2015-03-01

    Simulation of the low-temperature properties of many-body systems remains one of the major challenges in theoretical and experimental quantum information science. Firstly we demonstrate experimentally a Demon-like algorithmic cooling method that is applicable to any physical system that can be simulated by a quantum computer. This method allows us to distil and eliminate hot components of quantum states like a quantum Maxwell's demon. The experimental implementation is realized with a quantum optical network, and the results are in full agreement with theoretical predictions (with fidelity higher than 0.978). Secondly, we use the demon-like algorithmic cooling method to experimentally investigate Majorana zero modes exhibiting a fundamental property of non-Abelian statistics. This work was supported by the National Basic Research Program of China (2011CB921200), the CAS, The National Natural Science Foundaton of China.

  12. FLORIDA TOWER FOOTPRINT EXPERIMENTS

    SciTech Connect

    WATSON,T.B.; DIETZ, R.N.; WILKE, R.; HENDREY, G.; LEWIN, K.; NAGY, J.; LECLERC, M.

    2007-01-01

    The Florida Footprint experiments were a series of field programs in which perfluorocarbon tracers were released in different configurations centered on a flux tower to generate a data set that can be used to test transport and dispersion models. These models are used to determine the sources of the CO{sub 2} that cause the fluxes measured at eddy covariance towers. Experiments were conducted in a managed slash pine forest, 10 km northeast of Gainesville, Florida, in 2002, 2004, and 2006 and in atmospheric conditions that ranged from well mixed, to very stable, including the transition period between convective conditions at midday to stable conditions after sun set. There were a total of 15 experiments. The characteristics of the PFTs, details of sampling and analysis methods, quality control measures, and analytical statistics including confidence limits are presented. Details of the field programs including tracer release rates, tracer source configurations, and configuration of the samplers are discussed. The result of this experiment is a high quality, well documented tracer and meteorological data set that can be used to improve and validate canopy dispersion models.

  13. 76 FR 490 - Marking Meteorological Evaluation Towers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-05

    ...-2251. FOR FURTHER INFORMATION CONTACT: Sheri Edgett-Barron, Obstruction Evaluation Services, Air... Federal Aviation Administration 14 CFR Part 77 Marking Meteorological Evaluation Towers AGENCY: Federal... to include guidance for Meteorological Evaluation Towers (METs). These towers are erected in...

  14. Guard tower structural design concept for perimeter security systems

    SciTech Connect

    Risse, J.T.

    1983-07-01

    Facilities that require outdoor perimeter sensor fields to furnish perimeter penetration alarms can often benefit by the inclusion of manned guard towers in the total security plan. Acquisition and maintenance costs of closed circuit television to provide adequate visual assessment may be too costly and perhaps tower personnel could perform other functions such as monitoring vehicles or personnel in the vicinity of the protected area. Because there appeared to be no uniformity of design features for guard towers being built for nominally identical purposes, a program has been undertaken at Sandia National Laboratories to identify functions and features of towers, and to find a standard design such that security organizations, wishing to build a tower, would not find it necessary to start anew for each application. A tower design using prestressed concrete ''double tees'' has been worked out and reduced to practice that accomplishes many of the desired characteristics of a guard tower at reasonable cost. The prestressed concrete technology is available throughout the CONUS, Canada, Europe, etc. One such design is described and discussed.

  15. Tower details, sheet 16. San Bernardino Valley Union Junior College, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Tower details, sheet 16. San Bernardino Valley Union Junior College, Auditorium Building. Clock and finial details; tower roof plan. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 16, job no. 692. Various scales. July 15, 1937. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, July 24, 1937. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  16. Theory for synthetic aperture radar imaging of the ocean surface - With application to the Tower Ocean Wave and Radar Dependence experiment on focus, resolution, and wave height spectra

    NASA Astrophysics Data System (ADS)

    Kasilingam, Dayalan P.; Shemdin, Omar H.

    1988-11-01

    A one-dimensional model for simulating azimuthal SAR imaging of the ocean surface is developed which can admit both the 'distributed surface' and 'velocity bunching' approaches. Computer simulations demonstrate that the time-dependent modulation patterns due to the radar cross section variation and the velocity bunching effects provide optimum focusing around half the phase velocity of the long wave. The results indicate that in the Tower Ocean Wave and Radar Dependence experiment, SAR imaging at L band is approximately linear.

  17. Theory for synthetic aperture radar imaging of the ocean surface - With application to the Tower Ocean Wave and Radar Dependence experiment on focus, resolution, and wave height spectra

    NASA Technical Reports Server (NTRS)

    Kasilingam, Dayalan P.; Shemdin, Omar H.

    1988-01-01

    A one-dimensional model for simulating azimuthal SAR imaging of the ocean surface is developed which can admit both the 'distributed surface' and 'velocity bunching' approaches. Computer simulations demonstrate that the time-dependent modulation patterns due to the radar cross section variation and the velocity bunching effects provide optimum focusing around half the phase velocity of the long wave. The results indicate that in the Tower Ocean Wave and Radar Dependence experiment, SAR imaging at L band is approximately linear.

  18. State waste discharge permit application 400 Area secondary cooling water. Revision 2

    SciTech Connect

    1996-01-01

    This document constitutes the Washington Administrative Code 173-216 State Waste Discharge Permit Application that serves as interim compliance as required by Consent Order DE 91NM-177, for the 400 Area Secondary Cooling Water stream. As part of the Hanford Federal Facility Agreement and Consent Order negotiations, the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site that affect groundwater or have the potential to affect groundwater would be subject to permitting under the structure of Chapter 173-216 of the Washington Administrative Code, the State Waste Discharge Permitting Program. As a result of this decision, the Washington State Department of Ecology and the US Department of Energy, Richland Operations Office entered into Consent Order DE 91NM-177. The Consent Order DE 91NM-177 requires a series of permitting activities for liquid effluent discharges. Based upon compositional and flow rate characteristics, liquid effluent streams on the Hanford Site have been categorized into Phase 1, Phase 2, and Miscellaneous streams. This document only addresses the 400 Area Secondary Cooling Water stream, which has been identified as a Phase 2 stream. The 400 Area Secondary Cooling Water stream includes contribution streams from the Fuels and Materials Examination Facility, the Maintenance and Storage Facility, the 481-A pump house, and the Fast Flux Test Facility.

  19. Some techniques for reducing the tower shadow of the DOE/NASA mod-0 wind turbine tower. [wind tunnel tests to measure effects of tower structure on wind velocity

    NASA Technical Reports Server (NTRS)

    Burley, R. R.; Savino, J. M.; Wagner, L. H.; Diedrich, J. H.

    1979-01-01

    Wind speed profile measurements to measure the effect of a wind turbine tower on the wind velocity are presented. Measurements were made in the wake of scale models of the tower and in the wake of certain full scale components to determine the magnitude of the speed reduction (tower shadow). Shadow abatement techniques tested on the towers included the removal of diagonals, replacement of diagonals and horizontals with round cross section members, installation of elliptical shapes on horizontal members, installation of airfoils on vertical members, and application of surface roughness to vertical members.

  20. Forced- and natural-convection studies on solar collectors for heating and cooling applications

    NASA Astrophysics Data System (ADS)

    Pearson, J. T.

    1983-03-01

    Convection in air heating solar collectors for heating and cooling applications was studied. It was determined that improvement in the overall conductance between the absorber and the flowing air was an area that needed much improvement. Studies were performed to obtain several absorber convector configurations which have superior heat transfer performance, modest drop penalties, and a high potential for economical manufacturing. Four surfaces which may be fabricated from aluminum or steel are recommended. Three utilize corrugated sheets bonded to the backplate and/or the back side of the absorber. These three surfaces are recommended for applications where airflow behind the absorber is appropriate. For those applications where airflow above the absorber is appropriate, a louvered surface which can be fabricated from metal or plastic is recommended.

  1. On the geological origin of Devils Tower (WY, USA)

    NASA Astrophysics Data System (ADS)

    Zavada, P.; Dedecek, P.; Holloway, S. D.; Chang, J. C.; Crain, K.; Keller, G. R.

    2011-12-01

    The Devils Tower is an exceptional igneous rock formation and a dominating landmark of the northern plains in Wyoming (USA). It rises 250 m above the surrounding sedimentary formations. Previous hypotheses suggested that the Devils Tower was originally part of a magmatic intrusion; volcanic conduit, magmatic stock or a laccolith. Our review of the geological evidence suggests that the Devils Tower is a remnant of an eroded lava lake that filled a broad phreatomagmatic volcano crater. Our hypothesis is based on a detailed study of a similar phonolite landmark in Czech Republic, called Boren, and analogue modeling, finite element numerical modeling of cooling for various shapes of volcanic bodies, and results of field and gravity surveys of the area. The Devils Tower together with a group of five phonolite bodies called Missouri Buttes, located 6 km NW from the Devils Tower, represent the easternmost products of the Tertiary tectonomagmatic events related to the lithospheric-scale uplift of the Black hills monocline. The phreatomagmatic deposits in the surroundings of the Missouri Buttes and the Devils Tower suggest that these phonolite bodies were originally emplaced into phreatomagmatic maar-diatreme volcanoes. To reveal the original shape of the Devils Tower, we employed the analogue modeling using plaster of Paris as analogue for phonolite magma to study internal fabrics and shapes of extrusive/intrusive magmatic bodies emplaced into the maar-diatreme volcanoes. Then, the resulting shapes of analogue magmatic bodies were used for the Finite Element thermal numerical models of their cooling using the thermophysical parameters of the phonolite magma and the rock units surrounding the Devils Tower and Missouri Buttes. Because the columnar joints grow perpendicular to the isotherms in cooling igneous and volcanic bodies, we analyzed the match between the thermal structure of the FE models and the columnar jointing pattern on the Devils Tower. The best fit of the

  2. Water-cooled, high-intensity ultrasound surgical applicators with frequency tracking.

    PubMed

    Martin, Roy W; Vaezy, Shahram; Proctor, Andrew; Myntti, Terrence; Lee, Janelle B J; Crum, Lawrence A

    2003-10-01

    High-intensity, focused ultrasound (HIFU) applicators have been developed for arresting bleeding with the ultimate intent of use in surgery. The design uses a tapered titanium component for transmission coupling of the ultrasound energy from a spherically curved transducer to biological tissues. The nominal operating frequency is 5.5 MHz, in a highly resonant mode (quality factor of 327 with water load). Liquid cooling is used to remove energy loss important at net applied power greater than 18 W/cm2 at the surface of the piezoelectric element. A downward resonance frequency shift (>20 kHz) occurs, even with cooling, as the applicator warms with normal operation. A feedback technique is used for maintaining the excitation near optimum resonance. Standing wave ratios of the applied power of 1.6 or less are thus sustained. The system and applicators have been found to be highly robust, effective in achieving hemostasis in the hemorrhaging liver, spleen, lung, or blood vessels in rabbit and pig experiments. One unit has been operated for over 1.7 hours in treating organ hemorrhage in blunt trauma experiments with nine swine with electrical net power of up to 158 W (31 W/cm2 across the transducer) and intensity of 2560 W/cm2 at focus. PMID:14609070

  3. An Experimental Investigation of Rectangular Exhaust-Gas Ejectors Applicable for Engine Cooling

    NASA Technical Reports Server (NTRS)

    Manganiello, Eugene J; Bogatsky, Donald

    1945-01-01

    An experimental investigation of rectangular exhaust-gas ejector pumps was conducted to provide data that would serve as a guide to the design of ejector applications for aircraft engines with marginal cooling. The pumping characteristics of rectangular ejectors actuated by the exhaust of a single-cylinder aircraft engine were determined for a range of ejector mixing-section area from 20 to 50 square inches, over-all length from 12 to 42 inches, aspect ratio from 1 to 5, diffusing exit area from 20 to 81 square inches, and exhaust-nozzle aspect ratio from 1 to 42.

  4. Towers of Gravitational Theories

    NASA Astrophysics Data System (ADS)

    Goldberger, Walter D.; Rothstein, Ira Z.

    In this essay, we introduce a theoretical framework designed to describe black hole dynamics. The difficulties in understanding such dynamics stems from the proliferation of scales involved when one attempts to simultaneously describe all of the relevant dynamical degrees of freedom. These range from the modes that describe the black hole horizon, which are responsible for dissipative effects, to the long wavelength gravitational radiation that drains mechanical energy from macroscopic black hole bound states. We approach the problem from a Wilsonian point of view, by building a tower of theories of gravity each of which is valid at different scales. The methodology leads to multiple new results in diverse topics including phase transitions of Kaluza-Klein black holes and the interactions of spinning black hole in non-relativistic orbits. Moreover, our methods tie together speculative ideas regarding dualities for black hole horizons to real physical measurements in gravitational wave detectors.

  5. Towers of gravitational theories

    NASA Astrophysics Data System (ADS)

    Goldberger, Walter D.; Rothstein, Ira Z.

    2006-11-01

    In this essay we introduce a theoretical framework designed to describe black hole dynamics. The difficulties in understanding such dynamics stems from the proliferation of scales involved when one attempts to simultaneously describe all of the relevant dynamical degrees of freedom. These range from the modes that describe the black hole horizon, which are responsible for dissipative effects, to the long wavelength gravitational radiation that drains mechanical energy from macroscopic black hole bound states. We approach the problem from a Wilsonian point of view, by building a tower of theories of gravity each of which is valid at different scales. The methodology leads to multiple new results in diverse topics including phase transitions of Kaluza-Klein black holes and the interactions of spinning black hole in non-relativistic orbits. Moreover, our methods tie together speculative ideas regarding dualities for black hole horizons to real physical measurements in gravitational wave detectors.

  6. Analysis and comparison of wall cooling schemes for advanced gas turbine applications

    NASA Technical Reports Server (NTRS)

    Colladay, R. S.

    1972-01-01

    The relative performance of (1) counterflow film cooling, (2) parallel-flow film cooling, (3) convection cooling, (4) adiabatic film cooling, (5) transpiration cooling, and (6) full-coverage film cooling was investigated for heat loading conditions expected in future gas turbine engines. Assumed in the analysis were hot-gas conditions of 2200 K (3500 F) recovery temperature, 5 to 40 atmospheres total pressure, and 0.6 gas Mach number and a cooling air supply temperature of 811 K (1000 F). The first three cooling methods involve film cooling from slots. Counterflow and parallel flow describe the direction of convection cooling air along the inside surface of the wall relative to the main gas flow direction. The importance of utilizing the heat sink available in the coolant for convection cooling prior to film injection is illustrated.

  7. Report on Preliminary Engineering Study for Installation of an Air Cooled Steam Condenser at Brawley Geothermal Plant, Unit No. 1

    SciTech Connect

    1982-03-01

    The Brawley Geothermal Project comprises a single 10 MW nominal geothermal steam turbine-generator unit which has been constructed and operated by the Southern California Edison Company (SCE). Geothermal steam for the unit is supplied through contract by Union Oil Company which requires the return of all condensate. Irrigation District (IID) purchases the electric power generated and provides irrigation water for cooling tower make-up to the plant for the first-five years of operation, commencing mid-1980. Because of the unavailability of irrigation water from IID in the future, SCE is investigating the application and installation of air cooled heat exchangers in conjunction with the existing wet (evaporative) cooling tower with make-up based on use of 180 gpm (nominal) of the geothermal condensate which may be made available by the steam supplier.

  8. The Drop Tower Bremen -Experiment Operation

    NASA Astrophysics Data System (ADS)

    Könemann, Thorben; von Kampen, Peter; Rath, Hans J.

    The idea behind the drop tower facility of the Center of Applied Space Technology and Micro-gravity (ZARM) in Bremen is to provide an inimitable technical opportunity of a daily access to short-term weightlessness on earth. In this way ZARM`s european unique ground-based microgravity laboratory displays an excellent economic alternative for research in space-related conditions at low costs comparable to orbital platforms. Many national and international ex-perimentalists motivated by these prospects decide to benefit from the high-quality and easy accessible microgravity environment only provided by the Drop Tower Bremen. Corresponding experiments in reduced gravity could open new perspectives of investigation methods and give scientists an impressive potential for a future technology and multidisciplinary applications on different research fields like Fundamental Physics, Astrophysics, Fluid Dynamics, Combus-tion, Material Science, Chemistry and Biology. Generally, realizing microgravity experiments at ZARM`s drop tower facility meet new requirements of the experimental hardware and may lead to some technical constraints in the setups. In any case the ZARM Drop Tower Operation and Service Company (ZARM FAB mbH) maintaining the drop tower facility is prepared to as-sist experimentalists by offering own air-conditioned laboratories, clean rooms, workshops and consulting engineers, as well as scientific personal. Furthermore, ZARM`s on-site apartment can be used for accommodations during the experiment campaigns. In terms of approaching drop tower experimenting, consulting of experimentalists is mandatory to successfully accomplish the pursued drop or catapult capsule experiment. For this purpose there will be a lot of expertise and help given by ZARM FAB mbH in strong cooperation to-gether with the experimentalists. However, in comparison to standard laboratory setups the drop or catapult capsule setup seems to be completely different at first view. While defining a

  9. You're a What?: Tower Technician

    ERIC Educational Resources Information Center

    Vilorio, Dennis

    2012-01-01

    In this article, the author talks about the role and functions of a tower technician. A tower technician climbs up the face of telecommunications towers to remove, install, test, maintain, and repair a variety of equipment--from antennas to light bulbs. Tower technicians also build shelters and radiofrequency shields for electronic equipment, lay…

  10. On the applicability of surrogate-based MCMC-Bayesian inversion to the Community Land Model: Case studies at Flux tower sites

    DOE PAGESBeta

    Huang, Maoyi; Ray, Jaideep; Hou, Zhangshuan; Ren, Huiying; Liu, Ying; Swiler, Laura

    2016-06-01

    The Community Land Model (CLM) has been widely used in climate and Earth system modeling. Accurate estimation of model parameters is needed for reliable model simulations and predictions under current and future conditions, respectively. In our previous work, a subset of hydrological parameters has been identified to have significant impact on surface energy fluxes at selected flux tower sites based on parameter screening and sensitivity analysis, which indicate that the parameters could potentially be estimated from surface flux observations at the towers. To date, such estimates do not exist. In this paper, we assess the feasibility of applying a Bayesianmore » model calibration technique to estimate CLM parameters at selected flux tower sites under various site conditions. The parameters are estimated as a joint probability density function (PDF) that provides estimates of uncertainty of the parameters being inverted, conditional on climatologically-average latent heat fluxes derived from observations. We find that the simulated mean latent heat fluxes from CLM using the calibrated parameters are generally improved at all sites when compared to those obtained with CLM simulations using default parameter sets. Further, our calibration method also results in credibility bounds around the simulated mean fluxes which bracket the measured data. The modes (or maximum a posteriori values) and 95% credibility intervals of the site-specific posterior PDFs are tabulated as suggested parameter values for each site. Lastly, analysis of relationships between the posterior PDFs and site conditions suggests that the parameter values are likely correlated with the plant functional type, which needs to be confirmed in future studies by extending the approach to more sites.« less

  11. On the applicability of surrogate-based Markov chain Monte Carlo-Bayesian inversion to the Community Land Model: Case studies at flux tower sites

    NASA Astrophysics Data System (ADS)

    Huang, Maoyi; Ray, Jaideep; Hou, Zhangshuan; Ren, Huiying; Liu, Ying; Swiler, Laura

    2016-07-01

    The Community Land Model (CLM) has been widely used in climate and Earth system modeling. Accurate estimation of model parameters is needed for reliable model simulations and predictions under current and future conditions, respectively. In our previous work, a subset of hydrological parameters has been identified to have significant impact on surface energy fluxes at selected flux tower sites based on parameter screening and sensitivity analysis, which indicate that the parameters could potentially be estimated from surface flux observations at the towers. To date, such estimates do not exist. In this paper, we assess the feasibility of applying a Bayesian model calibration technique to estimate CLM parameters at selected flux tower sites under various site conditions. The parameters are estimated as a joint probability density function (PDF) that provides estimates of uncertainty of the parameters being inverted, conditional on climatologically average latent heat fluxes derived from observations. We find that the simulated mean latent heat fluxes from CLM using the calibrated parameters are generally improved at all sites when compared to those obtained with CLM simulations using default parameter sets. Further, our calibration method also results in credibility bounds around the simulated mean fluxes which bracket the measured data. The modes (or maximum a posteriori values) and 95% credibility intervals of the site-specific posterior PDFs are tabulated as suggested parameter values for each site. Analysis of relationships between the posterior PDFs and site conditions suggests that the parameter values are likely correlated with the plant functional type, which needs to be confirmed in future studies by extending the approach to more sites.

  12. The Physics of Shot Towers

    ERIC Educational Resources Information Center

    Lipscombe, Trevor C.; Mungan, Carl E.

    2012-01-01

    In the late 18th and throughout the 19th century, lead shot for muskets was prepared by use of a shot tower. Molten lead was poured from the top of a tower and, during its fall, the drops became spherical under the action of surface tension. In this article, we ask and answer the question: "How does the size of the lead shot depend on the height…

  13. Tower Temperature and Humidity Sensors (TWR) Handbook

    SciTech Connect

    Cook, DR

    2010-02-01

    Three tall towers are installed at the Atmospheric Radiation Measurement (ARM) Climate Research Facility: a 60-meter triangular tower at the Southern Great Plains (SGP) Central Facility (CF), a 21-meter walkup scaffolding tower at the SGP Okmulgee forest site (E21), and a 40-meter triangular tower at the North Slope of Alaska (NSA) Barrow site. The towers are used for meteorological, radiological, and other measurements.

  14. Application of Gamma code coupled with turbomachinery models for high temperature gas-cooled reactors

    SciTech Connect

    Chang Oh

    2008-02-01

    The very high-temperature gas-cooled reactor (VHTR) is envisioned as a single- or dual-purpose reactor for electricity and hydrogen generation. The concept has average coolant temperatures above 9000C and operational fuel temperatures above 12500C. The concept provides the potential for increased energy conversion efficiency and for high-temperature process heat application in addition to power generation. While all the High Temperature Gas Cooled Reactor (HTGR) concepts have sufficiently high temperature to support process heat applications, such as coal gasification, desalination or cogenerative processes, the VHTR’s higher temperatures allow broader applications, including thermochemical hydrogen production. However, the very high temperatures of this reactor concept can be detrimental to safety if a loss-ofcoolant accident (LOCA) occurs. Following the loss of coolant through the break and coolant depressurization, air will enter the core through the break by molecular diffusion and ultimately by natural convection, leading to oxidation of the in-core graphite structure and fuel. The oxidation will accelerate heatup of the reactor core and the release of a toxic gas, CO, and fission products. Thus, without any effective countermeasures, a pipe break may lead to significant fuel damage and fission product release. Prior to the start of this Korean/United States collaboration, no computer codes were available that had been sufficiently developed and validated to reliably simulate a LOCA in the VHTR. Therefore, we have worked for the past three years on developing and validating advanced computational methods for simulating LOCAs in a VHTR. GAMMA code is being developed to implement turbomachinery models in the power conversion unit (PCU) and ultimately models associated with the hydrogen plant. Some preliminary results will be described in this paper.

  15. High-power laser phosphor light source with liquid cooling for digital cinema applications

    NASA Astrophysics Data System (ADS)

    Li, Kenneth

    2014-02-01

    Laser excited phosphor has been used to excite phosphor material, producing high intensity light output with smaller etendue than that of LEDs with the same long lifetime. But due to the high intensity of the laser light, phosphor with organic binder burns at low power, which requires the phosphor to be deposited on a rotating wheel in practical applications. Phosphor with inorganic binders, commonly known as ceramic phosphor, on the other hand, does not burn, but efficiency goes down as temperature goes up under high power excitation. This paper describes cooling schemes in sealed chambers such that the phosphor materials using organic or inorganic binders can be liquid cooled for high efficiency operations. Confined air bubbles are introduced into the sealed chamber accommodating the differential thermal expansion of the liquid and the chamber. For even higher power operation suitable for digital cinema, a suspension of phosphor in liquid is described suitable for screen brightness of over 30,000 lumens. The aging issues of phosphor can also be solved by using replaceable phosphor cartridges.

  16. Theoretical model of internally cooled interstitial ultrasound applicators for thermal therapy

    NASA Astrophysics Data System (ADS)

    Tyréus, Per Daniel; Diederich, Chris J.

    2002-04-01

    Interstitial ultrasound applicators for high-temperature thermal therapy are currently being developed for treating cancerous and benign disease. Internally cooled, direct-coupled (ICDC) applicators, composed of a segmented array of cylindrical ultrasound transducers, have demonstrated capabilities of producing controllable and conformal heating distributions along the applicator length and angular orientation. In this study, 2D transient acoustic and biothermal models of ICDC applicators were developed using a mixed implicit and explicit finite difference solution with variable node spacing in cylindrical coordinates for enhanced speed, stability and accuracy. The model incorporates dynamic behaviour of acoustic parameters and blood perfusion as a function of temperature and thermal dose. Acoustic intensity distributions were modelled as a composite of measured and theoretical intensity distributions. The shape and time evolution of temperature contours and thermal lesions for 90°, 200° and 360° angularly directional applicators and multi-transducer applicators were modelled for heating durations between 1 and 5 min. Model parameters were selected to match previously reported ex vivo and in vivo studies of 2.2 mm diameter ICDC devices in thigh muscle and liver (15-30 W cm-2 applied power density, 0.5-5 min treatment times, 2.8-3.6 cm diameter thermal lesions). The temperatures and lethal thermal dose (600 EM43 °C) contours calculated using the models were in excellent agreement with temperatures and thermal lesion dimensions (visible coagulation) determined experimentally. The differences between maximum radial depths of coagulation calculated using the r-z and r-θ models were small, less than ~2 mm for 10-15 mm lesions. There was a strong correlation between the calculated 50 °C contour and the radial, angular and axial lesion dimensions obtained for 3-5 min heating protocols. The models developed in this study have significant application in design studies

  17. Uncertainty analysis of eddy covariance CO2 flux measurements for different EC tower distances using an extended two-tower approach

    NASA Astrophysics Data System (ADS)

    Post, H.; Hendricks Franssen, H. J.; Graf, A.; Schmidt, M.; Vereecken, H.

    2015-02-01

    The use of eddy covariance (EC) CO2 flux measurements in data assimilation and other applications requires an estimate of the random uncertainty. In previous studies, the (classical) two-tower approach has yielded robust uncertainty estimates, but care must be taken to meet the often competing requirements of statistical independence (non-overlapping footprints) and ecosystem homogeneity when choosing an appropriate tower distance. The role of the tower distance was investigated with help of a roving station separated between 8 m and 34 km from a permanent EC grassland station. Random uncertainty was estimated for five separation distances with the classical two-tower approach and an extended approach which removed systematic differences of CO2 fluxes measured at two EC towers. This analysis was made for a data set where (i) only similar weather conditions at the two sites were included, and (ii) an unfiltered one. The extended approach, applied to weather-filtered data for separation distances of 95 and 173 m gave uncertainty estimates in best correspondence with an independent reference method. The introduced correction for systematic flux differences considerably reduced the overestimation of the two-tower based uncertainty of net CO2 flux measurements and decreased the sensitivity of results to tower distance. We therefore conclude that corrections for systematic flux differences (e.g., caused by different environmental conditions at both EC towers) can help to apply the two-tower approach to more site pairs with less ideal conditions.

  18. Application of Pulsed Electrical Fields for Advanced Cooling and Water Recovery in Coal-Fired Power Plant

    SciTech Connect

    Young Cho; Alexander Fridman

    2009-04-02

    The overall objective of the present work was to develop technologies to reduce freshwater consumption in a cooling tower of coal-based power plant so that one could significantly reduce the need of make-up water. The specific goal was to develop a scale prevention technology based an integrated system of physical water treatment (PWT) and a novel filtration method so that one could reduce the need for the water blowdown, which accounts approximately 30% of water loss in a cooling tower. The present study investigated if a pulsed spark discharge in water could be used to remove deposits from the filter membrane. The test setup included a circulating water loop and a pulsed power system. The present experiments used artificially hardened water with hardness of 1,000 mg/L of CaCO{sub 3} made from a mixture of calcium chloride (CaCl{sub 2}) and sodium carbonate (Na{sub 2}CO{sub 3}) in order to produce calcium carbonate deposits on the filter membrane. Spark discharge in water was found to produce strong shockwaves in water, and the efficiency of the spark discharge in cleaning filter surface was evaluated by measuring the pressure drop across the filter over time. Results showed that the pressure drop could be reduced to the value corresponding to the initial clean state and after that the filter could be maintained at the initial state almost indefinitely, confirming the validity of the present concept of pulsed spark discharge in water to clean dirty filter. The present study also investigated the effect of a plasma-assisted self-cleaning filter on the performance of physical water treatment (PWT) solenoid coil for the mitigation of mineral fouling in a concentric counterflow heat exchanger. The self-cleaning filter utilized shockwaves produced by pulse-spark discharges in water to continuously remove scale deposits from the surface of the filter, thus keeping the pressure drop across the filter at a relatively low value. Artificial hard water was used in the

  19. Characterization of an inline row impingement channel for turbine blade cooling applications

    NASA Astrophysics Data System (ADS)

    Ricklick, Mark A.

    height effects on the performance of the channel side walls, effects of bulk temperature increase on heat transfer coefficients, circumferential heat variation effects, and effects on the uniformity of the heat transfer distribution. The main objectives of this dissertation are to explore the various previously unstudied characteristics of impingement channels, in order to sufficiently predict their performance in a wide range of applications. The potential exists, therefore, for a designer to develop a blade with cooling characteristics specifically tailored to the expected component thermal loads. Temperature sensitive paint (TSP) is one of several non-intrusive optical temperature measurements techniques that have gained a significant amount of popularity in the last decade. By employing the use of TSP, we have the ability to provide very accurate (less than 1 degree Celsius uncertainty), high resolution full-field temperature measurements. This has allowed us to investigate the local heat transfer characteristics of the various channel surfaces under a variety of steady state testing conditions. The comparison of thermal performance and uniformity for each impingement channel configuration then highlights the benefits and disadvantages of various configurations. Through these investigations, it has been shown that the channel side walls provide heat transfer coefficients comparable to those found on the target surface, especially at small impingement heights. Although the side walls suffer from highly non uniform performance near the start of the channel, the profiles become very uniform as the cross flow develops and becomes a dominating contributor to the heat transfer coefficient. Increases in channel height result in increased non-uniformity in the streamwise direction and decreased heat transfer levels. Bulk temperature increases have also been shown to be an important consideration when investigating surfaces dominated by cross flow heat transfer effects, as

  20. Reliable cool-down of GridPix detectors for cryogenic applications

    NASA Astrophysics Data System (ADS)

    Schön, R.; Schmitz, J.; Smits, S.; Bilevych, Y.; van Bakel, N.

    2015-04-01

    In this paper we present thermal cycling experiments of GridPix radiation imaging detectors, in view of a potential application in a cryogenic experiment. The robustness of the GridPix detector is studied for various grid designs, as well as various mechanical and thermal surroundings. The grid design variations had insignificant effect on the grid strength. A low cool-down rate as well as good thermal contact are crucial for the durability of the grid. Further, additional strengthening at the grid edges proved necessary to maintain the integrity of the structure during thermal cycling, which was done using globtop adhesive. The combination of these measures led to 100% survival rate after thermal cycling down to -130 °C.

  1. Deployable tensegrity towers

    NASA Astrophysics Data System (ADS)

    Pinaud, Jean-Paul

    The design of a complete tensegrity system involves the analysis of static equilibria, the mechanical properties of the configuration, the deployment of the structure, and the regulation and dynamics of the system. This dissertation will explore these steps for two different types of structures. The first structure is the traditional Snelson Tower, where struts are disjointed, and is referred to as a Class 1 tensegrity. The second structure of interest is referred to as a Class 2 structure, where two struts come in contact at a joint. The first part of the thesis involves the dynamics of these tensegrity structures. Two complete nonlinear formulations for the dynamics of tensegrity systems are derived. In addition, a general formulation for the statics for an arbitrary tensegrity structure resulted from one of the dynamic formulations and is presented with symmetric and nonsymmetric tensegrity configurations. The second part of the thesis involves statics. The analysis of static equilibria and the implementation of this analysis into an open loop control law that will deploy the tensegrity structures along an equilibrium manifold are derived. The analysis of small stable tensegrity units allow for a modular design, where a collection of these units can be assembled into a larger structure that obeys the same control laws for deployment concepts. In addition, a loaded structure is analyzed to determine the optimal number of units required to obtain a minimal mass configuration. The third part of the thesis involves laboratory hardware that demonstrates the practical use of the methodology presented. A Class 2 symmetric structure is constructed, deployed, and stowed using the analysis from part two. In addition, the static equilibria of a Class 1 structure is computed to obtain nonsymmetric reconfigurations. The final part of the thesis involves the attenuation of white noise disturbances acting on nodes of both structures. The structures are simulated using linear

  2. Solar heating and cooling with the CaCl2-CH3OH chemical heat pump

    NASA Astrophysics Data System (ADS)

    Offenhartz, P. O.

    1982-03-01

    A chemical heat pump based on the reaction of calcium chloride and methanol is being designed and optimized for solar heating and air conditioning, primarily for the residential and light commercial market. The performance requirements for this application are quite stringent. For example, to minimize maintenance, a cooling tower should not be used, and the solar collectors should be fixed rooftop flat plates or evacuated tubes. The chiller should be capable of reaching 45 F on a 95 F day in order to provide effective dehumidification. Energy storage for late afternoon and early evening cooling, as well as night time winter heating, must be provided.

  3. Low-Temperature Thermoelectric Properties of PtSb2- x Te x for Cryogenic Peltier Cooling Applications

    NASA Astrophysics Data System (ADS)

    Waldrop, Spencer; Morelli, Donald

    2015-06-01

    PtSb2 is a potential material for cryogenic Peltier cooling applications because of its semimetal character with a high Seebeck coefficient and low electrical resistivity. To investigate the effects of n-type doping we studied PtSb2- x Te x with x between 0 and 0.04. A clear doping effect was observed, and the power factor was maximized for samples with x = 0.005, 0.02, and 0.04. If thermal conductivity reduction techniques can be used, this material may be a promising candidate for cryogenic Peltier cooling applications.

  4. Measuring the anti-Stokes luminescence of CdSe/ZnS quantum dots for laser cooling applications

    NASA Astrophysics Data System (ADS)

    Fontenot, Ross S.; Mathur, Veerendra K.; Barkyoumb, John H.; Mungan, Carl E.; Tran, Thanh N.

    2016-05-01

    The first demonstration of laser cooling of solids was of an ytterbium doped fluorozirconate glass. While this groundbreaking work successfully showed that it is possible to cool solids using laser cooling, rare-earth materials are governed by Boltzmann statistics limiting their cooling ability to about 100 K. Direct-bandgap semiconductors, on the other hand, are governed by Fermi-Dirac statistics, which allows for a theoretical cooling limit of 10 K as well as higher cooling efficiencies. Recently, it was demonstrated that it is possible to cool CdS nanoribbons by 40 K. That success was attributed to CdS strong electron-phonon coupling, which makes it possible to resonantly annihilate more than one longitudinal optical phonon during each up conversion cycle. To further increase the cooling power, large external quantum efficiency is required. A nanostructure is preferred because it creates confined excitons of tunable wavelength and reduces the self-absorption of the anti-Stokes fluorescence owing to the shorter path length for photons to escape the crystal. However, organically passivated quantum dots have a low quantum yield due to surface related trap states. A core-shell nanostructure alleviates this problem by passivating the surface trap states and protecting against environmental changes and photo-oxidative degradation. As such, we chose to investigate CdSe/ZnS core shell structure for laser cooling applications. This article highlights the measurement of the anti-Stokes luminescence, the dependence of the laser wavelength on the anti-Stokes emission of colloidal quantum dots, and the successful incorporation of CdSe/ZnS into polymers.

  5. Seeing the Fields and Forests: Application of Surface-Layer Theory and Flux-Tower Data to Calculating Vegetation Canopy Height

    NASA Astrophysics Data System (ADS)

    Pennypacker, Sam; Baldocchi, Dennis

    2016-02-01

    Canopy height is an important and dynamic site variable that affects the mass and energy exchanges between vegetation and the atmosphere. We develop a method to estimate canopy height routinely, using surface-layer theory and turbulence measurements made from a collection of flux towers. This tool is based on connecting the logarithmic wind profile generally expected in a neutral surface layer with direct measurements of friction velocity and assumptions about canopy height's relationships with zero-plane displacement and aerodynamic roughness length. Tests over a broad range of canopy types and heights find that calculated values are in good agreement with direct measurements of canopy height, including in a heterogeneous landscape. Based on the various uncertainties associated with our starting assumptions about canopy micrometeorology, we present a blueprint for future work that is necessary for expanding and improving these initial calculations.

  6. Sustained Growth of the Ex Vivo Ablation Zones' Critical Short Axis Using Gas-cooled Radiofrequency Applicators

    SciTech Connect

    Rempp, Hansjoerg; Scharpf, Marcus; Voigtlaender, Matthias; Schraml, Christina; Schmidt, Diethard; Fend, Falko; Claussen, Claus D.; Enderle, Markus D.; Pereira, Philippe L.; Clasen, Stephan

    2011-02-15

    Purpose: To evaluate the ablation zones created with a gas-cooled bipolar radiofrequency applicator performed on ex vivo bovine liver tissue. Materials and Methods: A total of 320 ablations with an internally gas-cooled bipolar radiofrequency applicator were performed on fresh ex vivo bovine liver tissue, varying the ablation time (5, 10, 15, and 20 min), power (20, 30, 40, and 50 W), and gas pressure of the CO{sub 2} used for cooling (585, 600, 615, 630, 645 psi), leading to a total of 80 different parameter combinations. Size and shape of the white coagulation zone were assessed. Results: The largest complete ablation zone was achieved after 20 min of implementing 50 W and 645 psi, resulting in a short axis of mean 46 {+-} 1 mm and a long axis of 56 {+-} 2 mm (mean {+-} standard deviation). Short-axis diameters increased between 5 and 20 min of ablation time at 585 psi (increase of the short axis was 45% at 30 W, 29% at 40 W, and 39% at 50 W). This increase was larger at 645 psi (113% at 30 W, 67% at 40 W, and 70% at 50 W). Macroscopic assessment and NADH (nicotinamide adenine dinucleotide) staining revealed incompletely ablated tissue along the needle track in 18 parameter combinations including low-power settings (20 and 30 W) and different cooling levels and ablation times. Conclusion: Gas-cooled radiofrequency applicators increase the short-axis diameter of coagulation in an ex vivo setting if appropriate parameters are selected.

  7. Cost benefits from applying advanced heat rejection concepts to a wet/dry-cooled binary geothermal plant

    SciTech Connect

    Faletti, D.W.

    1981-03-01

    Optimized ammonia heat rejection system designs were carried out for three water allocations equivalent to 9, 20, and 31% of that of a 100% wet-cooled plant. The Holt/Procon design of a 50-MWe binary geothermal plant for the Heber site was used as a design basis. The optimization process took into account the penalties for replacement power, gas turbine capital, and lost capacity due to increased heat rejection temperature, as well as added base plant capacity and fuel to provide fan and pump power to the heat rejection system. Descriptions of the three plant designs are presented. For comparison, a wet tower loop was costed out for a 100% wet-cooled plant using the parameters of the Holt/Procon design. Wet/dry cooling was found to increase the cost of electricity by 28% above that of a 100% wet-cooled plant for all three of the water allocations studied (9, 20, and 31%). The application selected for a preconceptual evaluation of the BCT (binary cooling tower) system was the use of agricultural waste water from the New River, located in California's Imperial Valley, to cool a 50-MWe binary geothermal plant. Technical and cost evaluations at the preconceptual level indicated that performance estimates provided by Tower Systems Incorporated (TSI) were reasonable and that TSI's tower cost, although 2 to 19% lower than PNL estimates, was also reasonable. Electrical cost comparisonswere made among the BCT system, a conventional 100% wet system, and a 9% wet/dry ammonia system, all using agricultural waste water with solar pond disposal. The BCT system cost the least, yielding a cost of electricity only 13% above that of a conventional wet system using high quality water and 14% less than either the conventional 100% wet or the 9% wet/dry ammonia system.

  8. Ice Thermal Storage Systems for LWR Supplemental Cooling and Peak Power Shifting

    SciTech Connect

    Haihua Zhao; Hongbin Zhang; Phil Sharpe; Blaise Hamanaka; Wei Yan; WoonSeong Jeong

    2010-06-01

    Availability of enough cooling water has been one of the major issues for the nuclear power plant site selection. Cooling water issues have frequently disrupted the normal operation at some nuclear power plants during heat waves and long draught. The issues become more severe due to the new round of nuclear power expansion and global warming. During hot summer days, cooling water leaving a power plant may become too hot to threaten aquatic life so that environmental regulations may force the plant to reduce power output or even temporarily to be shutdown. For new nuclear power plants to be built at areas without enough cooling water, dry cooling can be used to remove waste heat directly into the atmosphere. However, dry cooling will result in much lower thermal efficiency when the weather is hot. One potential solution for the above mentioned issues is to use ice thermal storage systems (ITS) that reduce cooling water requirements and boost the plant’s thermal efficiency in hot hours. ITS uses cheap off-peak electricity to make ice and uses those ice for supplemental cooling during peak demand time. ITS is suitable for supplemental cooling storage due to its very high energy storage density. ITS also provides a way to shift large amount of electricity from off peak time to peak time. Some gas turbine plants already use ITS to increase thermal efficiency during peak hours in summer. ITSs have also been widely used for building cooling to save energy cost. Among three cooling methods for LWR applications: once-through, wet cooling tower, and dry cooling tower, once-through cooling plants near a large water body like an ocean or a large lake and wet cooling plants can maintain the designed turbine backpressure (or condensation temperature) during 99% of the time; therefore, adding ITS to those plants will not generate large benefits. For once-through cooling plants near a limited water body like a river or a small lake, adding ITS can bring significant economic

  9. Tower-supported solar-energy collector

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K.

    1977-01-01

    Multiple-collector tower system supports three receiver/concentrators that absorb solar energy reflected from surrounding field of heliostats. System overcomes disadvantages of tower-supported collectors. Booms can be lowered during heavy winds to protect arms and collectors.

  10. Validation of Supersonic Film Cooling Modeling for Liquid Rocket Engine Applications

    NASA Technical Reports Server (NTRS)

    Morris, Christopher I.; Ruf, Joseph H.

    2010-01-01

    Topics include: upper stage engine key requirements and design drivers; Calspan "stage 1" results, He slot injection into hypersonic flow (air); test articles for shock generator diagram, slot injector details, and instrumentation positions; test conditions; modeling approach; 2-d grid used for film cooling simulations of test article; heat flux profiles from 2-d flat plate simulations (run #4); heat flux profiles from 2-d backward facing step simulations (run #43); isometric sketch of single coolant nozzle, and x-z grid of half-nozzle domain; comparison of 2-d and 3-d simulations of coolant nozzles (run #45); flowfield properties along coolant nozzle centerline (run #45); comparison of 3-d CFD nozzle flow calculations with experimental data; nozzle exit plane reduced to linear profile for use in 2-d film-cooling simulations (run #45); synthetic Schlieren image of coolant injection region (run #45); axial velocity profiles from 2-d film-cooling simulation (run #45); coolant mass fraction profiles from 2-d film-cooling simulation (run #45); heat flux profiles from 2-d film cooling simulations (run #45); heat flux profiles from 2-d film cooling simulations (runs #47, #45, and #47); 3-d grid used for film cooling simulations of test article; heat flux contours from 3-d film-cooling simulation (run #45); and heat flux profiles from 3-d and 2-d film cooling simulations (runs #44, #46, and #47).

  11. Uncertainty analysis of eddy covariance CO2 flux measurements for different EC tower distances using an extended two-tower approach

    NASA Astrophysics Data System (ADS)

    Post, H.; Hendricks Franssen, H. J.; Graf, A.; Schmidt, M.; Vereecken, H.

    2014-08-01

    The use of eddy covariance CO2 flux measurements in data assimilation and other applications requires an estimate of the random uncertainty. In previous studies, the two-tower approach has yielded robust uncertainty estimates, but care must be taken to meet the often competing requirements of statistical independence (non-overlapping footprints) and ecosystem homogeneity when choosing an appropriate tower distance. The role of the tower distance was investigated with help of a roving station separated between 8 m and 34 km from a permanent EC grassland station. Random uncertainty was estimated for five separation distances with an extended two-tower approach which removed systematic differences of CO2 fluxes measured at two EC towers. This analysis was made for a dataset where (i) only similar weather conditions at the two sites were included and (ii) an unfiltered one. The extended approach, applied to weather-filtered data for separation distances of 95 m and 173 m gave uncertainty estimates in best correspondence with the independent reference method The introduced correction for systematic flux differences considerably reduced the overestimation of the two-tower based uncertainty of net CO2 flux measurements, e.g. caused by different environmental conditions at both EC towers. It is concluded that the extension of the two-tower approach can help to receive more reliable uncertainty estimates because systematic differences of measured CO2 fluxes which are not part of random error are filtered out.

  12. 11. SITE BUILDING 002 SCANNER BUILDING EVAPORATIVE COOLING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. SITE BUILDING 002 - SCANNER BUILDING - EVAPORATIVE COOLING TOWER SYSTEM IN FOREGROUND. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  13. The Tower Shielding Facility: Its glorious past

    SciTech Connect

    Muckenthaler, F.J.

    1997-05-07

    The Tower Shielding Facility (TSF) is the only reactor facility in the US that was designed and built for radiation-shielding studies in which both the reactor source and shield samples could be raised into the air to allow measurements to be made without interference from ground scattering or other spurious effects. The TSF proved its usefulness as many different programs were successfully completed. It became active in work for the Defense Atomic Support Agency (DASA) Space Nuclear Auxiliary Power, Defense Nuclear Agency, Liquid Metal Fast Breeder Reactor Program, the Gas-Cooled and High-Temperature Gas-Cooled Reactor programs, and the Japanese-American Shielding Program of Experimental Research, just to mention a few of the more extensive ones. The history of the TSF as presented in this report describes the various experiments that were performed using the different reactors. The experiments are categorized as to the programs which they supported and placed in corresponding chapters. The experiments are described in modest detail, along with their purpose when appropriate. Discussion of the results is minimal, but references are given to more extensive topical reports.

  14. 29 CFR 1926.1435 - Tower cranes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Tower cranes. 1926.1435 Section 1926.1435 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Cranes and Derricks in Construction § 1926.1435 Tower cranes. (a) This section contains supplemental requirements for tower cranes; all sections of...

  15. 29 CFR 1926.1435 - Tower cranes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Tower cranes. 1926.1435 Section 1926.1435 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Cranes and Derricks in Construction § 1926.1435 Tower cranes. (a) This section contains supplemental requirements for tower cranes; all sections of...

  16. Liquid cooled garments

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Liquid cooled garments employed in several applications in which severe heat is encountered are discussed. In particular, the use of the garments to replace air line cooling units in a variety of industrial processing situations is discussed.

  17. Performance Assessment of a Desiccant Cooling System in a CHP Application with an IC Engine

    SciTech Connect

    Jalalzadeh-Azar, A. A.; Slayzak, S.; Judkoff, R.; Schaffhauser, T.; DeBlasio, R.

    2005-04-01

    Performance of a desiccant cooling system was evaluated in the context of combined heat and power (CHP). The baseline system incorporated a desiccant dehumidifier, a heat exchanger, an indirect evaporative cooler, and a direct evaporative cooler. The desiccant unit was regenerated through heat recovery from a gas-fired reciprocating internal combustion engine. The system offered sufficient sensible and latent cooling capacities for a wide range of climatic conditions, while allowing influx of outside air in excess of what is typically required for commercial buildings. Energy and water efficiencies of the desiccant cooling system were also evaluated and compared with those of a conventional system. The results of parametric assessments revealed the importance of using a heat exchanger for concurrent desiccant post cooling and regeneration air preheating. These functions resulted in enhancement of both the cooling performance and the thermal efficiency, which are essential for fuel utilization improvement. Two approaches for mixing of the return air and outside air were examined, and their impact on the system cooling performance and thermal efficiency was demonstrated. The scope of the parametric analyses also encompassed the impact of improving the indirect evaporative cooling effectiveness on the overall cooling system performance.

  18. Air pollution modeling and its application III

    SciTech Connect

    De Wispelaere, C.

    1984-01-01

    This book focuses on the Lagrangian modeling of air pollution. Modeling cooling tower and power plant plumes, modeling the dispersion of heavy gases, remote sensing as a tool for air pollution modeling, dispersion modeling including photochemistry, and the evaluation of model performances in practical applications are discussed. Specific topics considered include dispersion in the convective boundary layer, the application of personal computers to Lagrangian modeling, the dynamic interaction of cooling tower and stack plumes, the diffusion of heavy gases, correlation spectrometry as a tool for mesoscale air pollution modeling, Doppler acoustic sounding, tetroon flights, photochemical air quality simulation modeling, acid deposition of photochemical oxidation products, atmospheric diffusion modeling, applications of an integral plume rise model, and the estimation of diffuse hydrocarbon leakages from petrochemical factories. This volume constitutes the proceedings of the Thirteenth International Technical Meeting on Air Pollution Modeling and Its Application held in France in 1982.

  19. Closure temperature in cooling bi-mineralic systems: I. Definition and with application to REE-in-two-pyroxene thermometer

    NASA Astrophysics Data System (ADS)

    Yao, Lijing; Liang, Yan

    2015-08-01

    Closure temperature is an important concept to many diffusion related problems involving cooling. The basic idea and formulation were outlined in the seminal work of Dodson for cooling mono-mineralic systems. The Dodson's equation has been widely used to calculate closure temperatures for igneous and metamorphic rocks that contain more than one mineral. The purpose of this study is to examine closure temperatures in cooling bi-mineralic systems and to investigate the physical meaning of temperatures calculated using the REE-in-two-pyroxene thermometer. We conduct numerical simulations of diffusive redistribution of trace elements between two coexisting minerals under prescribed cooling using temperature-dependent diffusion coefficients and mineral-mineral partition coefficients. Following Dodson's treatment, the closure temperature in bi-mineralic systems can be defined by the evolution of either average trace element concentrations in the two minerals or their ratio. The latter defines an effective partition coefficient. Closure temperatures calculated based on the two definitions are compared for a range of cooling rates, grain sizes, mineral proportions, and temperature-dependent partition coefficients and diffusion coefficients. Temperatures defined by the effective partition coefficient are recommended. Application to diffusive redistribution of rare earth elements (REE) in orthopyroxene-clinopyroxene systems demonstrates that closure temperature differences among REE are small and hence their average value may be used as the closure temperature for the cooling two-pyroxene system. The average closure temperature of REE in the two-pyroxene system is essentially the same as the temperature calculated using the REE-in-two-pyroxene thermometer and practically independent of pyroxene modal abundance in the system. Differences in temperatures calculated using the REE- and major element-based two-pyroxene thermometers can be used to infer cooling rate of two

  20. Development of ytterbium-doped oxyfluoride glasses for laser cooling applications.

    PubMed

    Krishnaiah, Kummara Venkata; Soares de Lima Filho, Elton; Ledemi, Yannick; Nemova, Galina; Messaddeq, Younes; Kashyap, Raman

    2016-01-01

    Oxyfluoride glasses doped with 2, 5, 8, 12, 16 and 20 mol% of ytterbium (Yb(3+)) ions have been prepared by the conventional melt-quenching technique. Their optical, thermal and thermo-mechanical properties were characterized. Luminescence intensity at 1020 nm under laser excitation at 920 nm decreases with increasing Yb(3+) concentration, suggesting a decrease in the photoluminescence quantum yield (PLQY). The PLQY of the samples was measured with an integrating sphere using an absolute method. The highest PLQY was found to be 0.99(11) for the 2 mol% Yb(3+): glass and decreases with increasing Yb(3+) concentration. The mean fluorescence wavelength and background absorption of the samples were also evaluated. Upconversion luminescence under 975 nm laser excitation was observed and attributed to the presence of Tm(3+) and Er(3+) ions which exist as impurity traces with YbF3 starting powder. Decay curves for the Yb(3+): (2)F5/2 → (2)F7/2 transition exhibit single exponential behavior for all the samples, although lifetime decrease was observed for the excited level of Yb(3+) with increasing Yb(3+) concentration. Also observed are an increase in the PLQY and a slight decrease in lifetime with increasing the pump power. Finally, the potential of these oxyfluoride glasses with high PLQY and low background absorption for laser cooling applications is discussed. PMID:26915817

  1. Development of ytterbium-doped oxyfluoride glasses for laser cooling applications

    PubMed Central

    Krishnaiah, Kummara Venkata; Soares de Lima Filho, Elton; Ledemi, Yannick; Nemova, Galina; Messaddeq, Younes; Kashyap, Raman

    2016-01-01

    Oxyfluoride glasses doped with 2, 5, 8, 12, 16 and 20 mol% of ytterbium (Yb3+) ions have been prepared by the conventional melt-quenching technique. Their optical, thermal and thermo-mechanical properties were characterized. Luminescence intensity at 1020 nm under laser excitation at 920 nm decreases with increasing Yb3+ concentration, suggesting a decrease in the photoluminescence quantum yield (PLQY). The PLQY of the samples was measured with an integrating sphere using an absolute method. The highest PLQY was found to be 0.99(11) for the 2 mol% Yb3+: glass and decreases with increasing Yb3+ concentration. The mean fluorescence wavelength and background absorption of the samples were also evaluated. Upconversion luminescence under 975 nm laser excitation was observed and attributed to the presence of Tm3+ and Er3+ ions which exist as impurity traces with YbF3 starting powder. Decay curves for the Yb3+: 2F5/2 → 2F7/2 transition exhibit single exponential behavior for all the samples, although lifetime decrease was observed for the excited level of Yb3+ with increasing Yb3+ concentration. Also observed are an increase in the PLQY and a slight decrease in lifetime with increasing the pump power. Finally, the potential of these oxyfluoride glasses with high PLQY and low background absorption for laser cooling applications is discussed. PMID:26915817

  2. A novel trapezoid fin pattern applicable for air-cooled heat sink

    NASA Astrophysics Data System (ADS)

    Chen, Chien-Hung; Wang, Chi-Chuan

    2015-11-01

    The present study proposed a novel step or trapezoid surface design applicable to air-cooled heat sink under cross flow condition. A total of five heat sinks were made and tested, and the corresponding fin patterns are (a) plate fin; (b) step fin (step 1/3, 3 steps); (c) 2-step fin (step 1/2, 2 steps); (d) trapezoid fin (trap 1/3, cutting 1/3 length from the rear end) and (e) trapezoid fin (trap 1/2, cutting 1/2 length from the rear end). The design is based on the heat transfer augmentation via (1) longer perimeter of entrance region and (2) larger effective temperature difference at the rear part of the heat sink. From the test results, it is found that either step or trapezoid design can provide a higher heat transfer conductance and a lower pressure drop at a specified frontal velocity. The effective conductance of trap 1/3 design exceeds that of plate surface by approximately 38 % at a frontal velocity of 5 m s-1 while retains a lower pressure drop of 20 % with its surface area being reduced by 20.6 %. For comparisons exploiting the overall thermal resistance versus pumping power, the resultant thermal resistance of the proposed trapezoid design 1/3, still reveals a 10 % lower thermal resistance than the plate fin surface at a specified pumping power.

  3. Evaluation of water cooled supersonic temperature and pressure probes for application to 1366 K flows

    NASA Technical Reports Server (NTRS)

    Lagen, Nicholas; Seiner, John M.

    1990-01-01

    Water cooled supersonic probes are developed to investigate total pressure, static pressure, and total temperature in high-temperature jet plumes and thereby determine the mean flow properties. Two probe concepts, designed for operation at up to 1366 K in a Mach 2 flow, are tested on a water cooled nozzle. The two probe designs - the unsymmetric four-tube cooling configuration and the symmetric annular cooling design - take measurements at 755, 1089, and 1366 K of the three parameters. The cooled total and static pressure readings are found to agree with previous test results with uncooled configurations. The total-temperature probe, however, is affected by the introduction of water coolant, and effect which is explained by the increased heat transfer across the thermocouple-bead surface. Further investigation of the effect of coolant on the temperature probe is proposed to mitigate the effect and calculate more accurate temperatures in jet plumes.

  4. Design Evaluation Using Finite Element Analysis of Cooled Silicon Nitride Plates for a Turbine Blade Application

    NASA Technical Reports Server (NTRS)

    Abdul-Aziz, Ali; Baaklini, George Y.; Bhatt, Ramakrishna T.

    2001-01-01

    Two- and three-dimensional finite element analyses were performed on uncoated and thermal barrier coated (TBC) silicon nitride plates with and without internal cooling by air. Steady-state heat-transfer analyses were done to optimize the size and the geometry of the cooling channels to reduce thermal stresses, and to evaluate the thermal environment experienced by the plate during burner rig testing. The limited experimental data available were used to model the thermal profile exerted by the flame on the plate. Thermal stress analyses were performed to assess the stress response due to thermal loading. Contours for the temperature and the representative stresses for the plates were generated and presented for different cooling hole sizes and shapes. Analysis indicates that the TBC experienced higher stresses, and the temperature gradient was much reduced when the plate was internally cooled by air. The advantages and disadvantages of several cooling channel layouts were evaluated.

  5. Tower details, sheet 14. San Bernardino Valley Union Junior College, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Tower details, sheet 14. San Bernardino Valley Union Junior College, Auditorium Building. Plan and elevation of tower above sixth floor; section through stage ventilators; elevation, stage ventilators. G. Stanley Wilson, Architect, A.I.A., Riverside, California. Sheet 14, job no. 692. Scale 3/4 inch to the foot. March 27, 1936. Application no. 1446, approved by the State of California, Department of Public Works, Division of Architecture, April 22, 1936. - San Bernardino Valley College, Auditorium, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  6. Predicting the onset of transformation under noncontinuous cooling conditions. Part 2: Application to the austenite pearlite transformation

    SciTech Connect

    Pham, T.T.; Hawbolt, E.B.; Brimacombe, J.K.

    1995-08-01

    A detailed review of the additivity principle with respect to the incubation of the austenite decomposition was summarized in Part 1 of this two-part series and led to the concept of an ideal time-temperature-transformation (TTT) diagram. This curve is characteristic of the chemistry and austenite grain size in the steel and allows nonisothermal behavior to be described assuming additivity holds. The derivation of mathematical relationships between the ideal and experimental cooling data was presented in the first article. In this second article, an ideal curve for the austenite-to-pearlite transformation was derived from cooling data. The applicability of the ideal TTT curve for predicting the start of transformation under continuous cooling conditions was assessed for a range of cooling rates. Experiments were conducted under both isothermal and varying temperature conditions, including an industrial cooling schedule, using a Gleeble Thermal Simulator. Reasonable agreement was found between the predictions and the observed transformation start temperatures; predictions were consistent and compared favorably against other methods which have been frequently used to estimate the transformation start temperature for nonisothermal conditions.

  7. Tissue temperature control using a water-cooled applicator: implications for transurethral laser-induced thermotherapy of benign prostatic hyperplasia.

    PubMed

    Sturesson, C; Andersson-Engels, S

    1997-03-01

    A prototype to a water-cooled applicator to be used in transurethral laser-induced thermotherapy of benign prostatic hyperplasia was developed. The flexible applicator was made of Teflon tubes except for the distal outer part which was made of glass, providing a transparent medium for laser radiation and enabling efficient cooling of the surrounding tissue. For heating, laser light from a Nd:YAG laser emitting at 1064 nm, which was coupled into an optical fiber with an institutionally made diffusing tip, was used. Cooling was performed by flushing water through the applicator. By using a mathematical model it was possible to connect the temperature rise of the water in the applicator to the maximum tissue temperature. Tissue light absorption was calculated using Monte Carlo simulations and the heat conduction equation was solved numerically using a finite-difference technique. Experiments on porcine liver in vitro showed that the maximum tissue temperature could be estimated with an average accuracy of 0.4 degree C by measuring the difference in outlet and inlet applicator water temperature and using the thermal model. The results presented suggest that the described method for temperature control can be used during laser prostatectomy to maximize the lesion size while preventing carbonization. PMID:9089598

  8. Kinetic model for predicting the concentrations of active halogens species in chlorinated saline cooling waters. Final report

    SciTech Connect

    Haag, W.R.; Lietzke, M.H.

    1981-08-01

    A kinetic model has been developed for describing the speciation of chlorine-produced oxidants in seawater as a function of time. The model is applicable under a broad variety of conditions, including all pH range, salinities, temperatures, ammonia concentrations, organic amine concentrations, and chlorine doses likely to be encountered during power plant cooling water chlorination. However, the effects of sunlight are not considered. The model can also be applied to freshwater and recirculating water systems with cooling towers. The results of the model agree with expectation, however, complete verification is not feasible at the present because analytical methods for some of the predicted species are lacking.

  9. Hydrogen Storage in Wind Turbine Towers

    SciTech Connect

    Kottenstette, R.; Cotrell, J.

    2003-09-01

    Low-cost hydrogen storage is recognized as a cornerstone of a renewables-hydrogen economy. Modern utility-scale wind turbine towers are typically conical steel structures that, in addition to supporting the rotor, could be used to store hydrogen. This study has three objectives: (1) Identify the paramount considerations associated with using a wind turbine tower for hydrogen storage; (2)Propose and analyze a cost-effective design for a hydrogen-storing tower; and (3) Compare the cost of storage in hydrogen towers to the cost of storage in conventional pressure vessels. The paramount considerations associated with a hydrogen tower are corrosion (in the form of hydrogen embrittlement) and structural failure (through bursting or fatigue life degradation). Although hydrogen embrittlement (HE) requires more research, it does not appear to prohibit the use of turbine towers for hydrogen storage. Furthermore, the structural modifications required to store hydrogen in a tower are not cost prohibitive.

  10. Characterization of selected application of biomass energy technologies and a solar district heating and cooling system

    SciTech Connect

    D'Alessio, Dr., Gregory J.; Blaunstein, Robert P.

    1980-09-01

    The following systems are discussed: energy self-sufficient farms, wood gasification, energy from high-yield silviculture farms, and solar district heating and cooling. System descriptions and environmental data are included for each one. (MHR)

  11. Meteorological Towers Display for Windows NT

    Energy Science and Technology Software Center (ESTSC)

    1999-05-20

    The Towers Display Program provides a convenient means of graphically depicting current wind speed and direction from a network of meteorological monitoring stations. The program was designed primarily for emergency response applications and, therefore, plots observed wind directions as a transport direction, i.e., the direction toward which the wind would transport a release of an atmospheric contaminant. Tabular summaries of wind speed and direction as well as temperature, relative humidity, and atmospheric turbulence measured atmore » each monitoring station can be displayed. The current implementation of the product at SRS displays data from eight Weather INformation and Display (WIND) System meteorological towers at SRS, meteorological stations established jointly by SRS/WSRC and the Augusta/Richmond County Emergency Management Agency in Augusta, GA, and National Weather Service stations in Augusta, GA. Wind speed and direction are plotted in a Beaufort scale format at the location of the station on a geographic map of the area. A GUI provides for easy specification of a desired date and time for the data to be displayed.« less

  12. Four Operational Strategies For The Tower of Pisa

    NASA Astrophysics Data System (ADS)

    Bartolozzi, F.

    The operational strategies proposed for safeguarding the Leaning Tower all agree on the urgent need to lay a sub-foundation for guaranteeing the stability of the foundation soil, considerably decreasing the current pressure to a value compatible with its resistance characteristics. Their second common property is the creation of a static beneficial effect on the material forming the monument. This effect may be achieved by reducing the pressure in the material forming the Tower, by making the present inclination decrease considerably, or by means of a reinforcement ring on the most stressed parts of the Tower - if the present inclination is to remain unchanged - or with the combined action of both the inclination decrease and the reinforcement ring. Clearly, the choice of each operation must be made within the framework of the present and particular resistance conditions of the material. On the other hand, the four techniques differ structurally and operationally. The former aspects refer to laying structural elements, all equally effective, but different in conception and function - such as pillars, beams, hinges and tubular devices ­ to be laid in order to integrate the common sub-foundation and to be utilised with respect to each operational technique. The operational differences mainly depend on the different executive needs with respect to the structural elements to be laid. The operational aspect of the fourth technique is very simple, but particularly delicate, as are all techniques concerning the Tower. In relation to this, the operation must clearly be managed by a highly qualified and professional group of technicians and workers using the most appropriate and modern technological apparatus. I believe that the considerable delicacy of the operational stage does not obstruct the application of the proposed techniques, both because of the precarious safety conditions of the building (requiring a radical solution), and because the operations put into

  13. Beam localization in HIFU temperature measurements using thermocouples, with application to cooling by large blood vessels.

    PubMed

    Dasgupta, Subhashish; Banerjee, Rupak K; Hariharan, Prasanna; Myers, Matthew R

    2011-02-01

    Experimental studies of thermal effects in high-intensity focused ultrasound (HIFU) procedures are often performed with the aid of fine wire thermocouples positioned within tissue phantoms. Thermocouple measurements are subject to several types of error which must be accounted for before reliable inferences can be made on the basis of the measurements. Thermocouple artifact due to viscous heating is one source of error. A second is the uncertainty regarding the position of the beam relative to the target location or the thermocouple junction, due to the error in positioning the beam at the junction. This paper presents a method for determining the location of the beam relative to a fixed pair of thermocouples. The localization technique reduces the uncertainty introduced by positioning errors associated with very narrow HIFU beams. The technique is presented in the context of an investigation into the effect of blood flow through large vessels on the efficacy of HIFU procedures targeted near the vessel. Application of the beam localization method allowed conclusions regarding the effects of blood flow to be drawn from previously inconclusive (because of localization uncertainties) data. Comparison of the position-adjusted transient temperature profiles for flow rates of 0 and 400ml/min showed that blood flow can reduce temperature elevations by more than 10%, when the HIFU focus is within a 2mm distance from the vessel wall. At acoustic power levels of 17.3 and 24.8W there is a 20- to 70-fold decrease in thermal dose due to the convective cooling effect of blood flow, implying a shrinkage in lesion size. The beam-localization technique also revealed the level of thermocouple artifact as a function of sonication time, providing investigators with an indication of the quality of thermocouple data for a given exposure time. The maximum artifact was found to be double the measured temperature rise, during initial few seconds of sonication. PMID:20817250

  14. Ecological effects of density-independent mortality: application to cooling-water withdrawals.

    PubMed

    Newbold, Stephen C; Iovanna, Rich

    2007-03-01

    A wide variety of environmental stresses can cause density-independent mortality in species populations. One example is cooling-water withdrawals, which kill or injure many aquatic organisms near power plants and other industrial facilities. In the United States alone, hundreds of facilities withdraw trillions of gallons from inland and coastal waters every year to cool turbines and other manufacturing equipment. A number of detailed, site-specific studies of the effects of such cooling-water withdrawals have been conducted over the last 30 years, but only a few generalizations have been proposed in the peer-reviewed literature. In this paper we use a series of basic theoretical models to investigate the potential effects of density-independent mortality on species populations and ecosystems, with particular focus on the effects of cooling-water withdrawals on fish populations, fisheries, and aquatic communities. Among other results, we show that the effects of cooling-water withdrawals on a species will depend on the magnitude of other co-occurring stressors, environmental variability, the nature of the management regime in the associated fisheries, and the position of the species in the food web. The general models in this paper can provide a starting point for further empirical case studies and some preliminary conceptual guidance for decision makers who must choose between alternative policy options for controlling cooling-water withdrawals. PMID:17489247

  15. Investigation of a para-ortho hydrogen reactor for application to spacecraft sensor cooling

    NASA Technical Reports Server (NTRS)

    Nast, T. C.

    1983-01-01

    The utilization of solid hydrogen in space for sensor and instrument cooling is a very efficient technique for long term cooling or for cooling at high heat rates. The solid hydrogen can provide temperatures as low as 7 to 8 K to instruments. Vapor cooling is utilized to reduce parasitic heat inputs to the 7 to 8 K stage and is effective in providing intermediate cooling for instrument components operating at higher temperatures. The use of solid hydrogen in place of helium may lead to weight reductions as large as a factor of ten and an attendent reduction in system volume. The results of an investigation of a catalytic reactor for use with a solid hydrogen cooling system is presented. Trade studies were performed on several configurations of reactor to meet the requirements of high reactor efficiency with low pressure drop. Results for the selected reactor design are presented for both liquid hydrogen systems operating at near atmospheric pressure and the solid hydrogen cooler operating as low as 1 torr.

  16. Utilizing of inner porous structure in injection moulds for application of special cooling method

    NASA Astrophysics Data System (ADS)

    Seidl, M.; Bobek, J.; Šafka, J.; Habr, J.; Nováková, I.; Běhálek, L.

    2016-04-01

    The article is focused on impact evaluation of controlled inner structure of production tools and new cooling method on regulation of thermal processes for injection moulding technology. The mould inserts with porous structure were cooled by means of liquid CO2 which is very progressive cooling method and enables very fast and intensive heat transfer among the plastic product, the production tool and cooling medium. The inserts were created using rapid prototype technology (DLSM) and they had a bi-component structure consisting of thin compact surface layer and defined porous inner structure of open cell character where liquid CO2 was flowing through. This analyse includes the evaluation of cooling efficiency for different inner structures and different time profiles for dosing of liquid CO2 into the porous structure. The thermal processes were monitored using thermocouples and IR thermal analyse of product surface and experimental device. Intensive heat removal influenced also the final structure and the shape and dimensional accuracy of the moulded parts that were made of semi-crystalline polymer. The range of final impacts of using intensive cooling method on the plastic parts was defined by DSC and dimensional analyses.

  17. Evaluation of water cooled supersonic temperature and pressure probes for application to 2000 F flows

    NASA Technical Reports Server (NTRS)

    Lagen, Nicholas T.; Seiner, John M.

    1990-01-01

    The development of water cooled supersonic probes used to study high temperature jet plumes is addressed. These probes are: total pressure, static pressure, and total temperature. The motivation for these experiments is the determination of high temperature supersonic jet mean flow properties. A 3.54 inch exit diameter water cooled nozzle was used in the tests. It is designed for exit Mach 2 at 2000 F exit total temperature. Tests were conducted using water cooled probes capable of operating in Mach 2 flow, up to 2000 F total temperature. Of the two designs tested, an annular cooling method was chosen as superior. Data at the jet exit planes, and along the jet centerline, were obtained for total temperatures of 900 F, 1500 F, and 2000 F, for each of the probes. The data obtained from the total and static pressure probes are consistent with prior low temperature results. However, the data obtained from the total temperature probe was affected by the water coolant. The total temperature probe was tested up to 2000 F with, and without, the cooling system turned on to better understand the heat transfer process at the thermocouple bead. The rate of heat transfer across the thermocouple bead was greater when the coolant was turned on than when the coolant was turned off. This accounted for the lower temperature measurement by the cooled probe. The velocity and Mach number at the exit plane and centerline locations were determined from the Rayleigh-Pitot tube formula.

  18. Optimized He 2 cooling systems for space application. Behavior and handling of superfluid helium at G = 0, phase 1

    NASA Astrophysics Data System (ADS)

    Denner, H. D.; Klipping, G.; Lueders, K.; Schotte, K. D.; Schotte, U.; Szuecs, Z.; Ruppert, U.

    1983-06-01

    Increased reliability of He2 cooling systems for space applications is considered. An active phase separator (APS) with annular flow gap of variable length which allows variation of the cooling capacity over a wide range, developed for zero-g tests is described. Helium-tight electrical leadthroughs, a displacement transducer for low temperature application, a ball closure for use in combination with the APS, and gas/liquid detectors were developed. For temperature and liquid level measurement in narrow slits in laboratory as well as flight experiments, temperature sensors were developed. Three thickness measurement methods for He2 films are proposed: optical (1/10 000 to 1/100 mm), crystal (1/10 to the 7th power to 1/10 mm) and capacitive (1/10 to the 6th power to some mm).

  19. Airport Remote Tower Sensor Systems

    NASA Technical Reports Server (NTRS)

    Papasin, Richard; Gawdiak, Yuri; Maluf, David A.; Leidich, Christopher; Tran, Peter B.

    2001-01-01

    Remote Tower Sensor Systems (RTSS) are proof-of-concept prototypes being developed by NASA/Ames Research Center (NASA/ARC) with collaboration with the FAA (Federal Aviation Administration) and NOAA (National Oceanic Atmospheric Administration). RTSS began with the deployment of an Airport Approach Zone Camera System that includes real-time weather observations at San Francisco International Airport. The goal of this research is to develop, deploy, and demonstrate remotely operated cameras and sensors at several major airport hubs and un-towered airports. RTSS can provide real-time weather observations of airport approach zone. RTSS will integrate and test airport sensor packages that will allow remote access to realtime airport conditions and aircraft status.

  20. [The first application of therapeutic hypothermia in Poland--selective head cooling (Cool-Cap) with whole-body moderate hypothermia in a newborn with features of hypoxic ischemic encephalopathy].

    PubMed

    Gulczyńska, Ewa; Kesiak, Marcin; Kryszczyńska, Joanna; Gadzinowski, Janusz; Oszukowski, Przemysław

    2012-05-01

    The authors present the first application of therapeutic hypothermia in a newborn in Poland. The female newborn, born with severe asphyxia, was transported to a referral perinatal center where the method of brain cooling was possible. Severe hypoxic ischemic encephalopathy was confirmed by an integrated EEG. During the cooling procedure (which lasted 72 hours), no important side effects were noticed. The neurodevelopmental outcome of the baby assessed during the first 2 years of her life is normal. PMID:22708339

  1. Control of Carbon Nanotube Density and Tower Height in an Array

    NASA Technical Reports Server (NTRS)

    Delzeit, Lance D. (Inventor); Schipper, John F. (Inventor)

    2010-01-01

    A method for controlling density or tower height of carbon nanotube (CNT) arrays grown in spaced apart first and second regions on a substrate. CNTs having a first density range (or first tower height range) are grown in the first region using a first source temperature range for growth. Subsequently or simultaneously, CNTs having a second density range (or second tower height range), having an average density (or average tower height) in the second region different from the average density (or average tower height) for the first region, are grown in the second region, using supplemental localized hearing for the second region. Application for thermal dissipation and/or dissipation of electrical charge or voltage in an electronic device are discussed.

  2. Preliminary Design, Feasibility and Cost Evaluation of 1- to 15-Kilometer Height Steel Towers

    NASA Technical Reports Server (NTRS)

    Shanker, Ajay

    2003-01-01

    Design and construction of tall towers is an on-going research program of NASA. The agency has already done preliminary review in this area and has determined that multi-kilometer height towers are technically and economically feasible. The proposed towers will provide high altitude launch platforms reaching above eighty percent of Earth's atmosphere and provide tremendous gains in the potential energy as well as substantial reduction in aerodynamic drag. NASA has also determined that a 15-KM tower will have many useful applications in: (i)Meteorology,(ii)Oceanography, (iii)Astronomy, (iv)High Altitude Launch, (v)Physics Drop Tower, (vi) Biosphere Research, (vii) Nanotechnology, (viii) Energy/Power, (ix)Broadband Wireless Technology, (x)Space Transportation and (xi)Space Tourism.

  3. Use of Air2Air Technology to Recover Fresh-Water from the Normal Evaporative Cooling Loss at Coal-Based Thermoelectric Power Plants

    SciTech Connect

    Ken Mortensen

    2009-06-30

    This program was undertaken to build and operate the first Air2Air{trademark} Water Conservation Cooling Tower at a power plant, giving a validated basis and capability for water conservation by this method. Air2Air{trademark} water conservation technology recovers a portion of the traditional cooling tower evaporate. The Condensing Module provides an air-to-air heat exchanger above the wet fill media, extracting the heat from the hot saturated moist air leaving in the cooling tower and condensing water. The rate of evaporate water recovery is typically 10%-25% annually, depending on the cooling tower location (climate).

  4. Establishing feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.

    1986-01-01

    At the present time all experimental towers (chimneys) are completed and operating. This consists of both a solar updraft and a natural-evaporative downdraft tower retrofitted to an existing residence structure and a greenhouse. The residential, experimental, natural-draft cooling system was completed in May, 1985, and five months of summer data on a Hewlet Packard 85 data acquisition computer with a digital voltmeter were acquired. The cooling tower and solar chimney on the experimental greenhouse became operational in September of 1985. A conceptual drawing of both the greenhouse and the residence natural-draft towers is included in the appendix along with the September 85 progress report.

  5. 40 CFR 63.1329 - Process contact cooling towers provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... viscosity multiple end finisher process, and who is subject or becomes subject to 40 CFR part 60, subpart... operators shall follow the procedures specified in 40 CFR 60.564(j)(1), except as provided in paragraph (c... procedures specified in 40 CFR 60.564(j)(1)(i). An average ethylene glycol concentration by weight shall...

  6. 40 CFR 63.1329 - Process contact cooling towers provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... high viscosity multiple end finisher process and who is subject or becomes subject to 40 CFR part 60... operators shall follow the procedures specified in 40 CFR 60.564(j)(1), except as provided in paragraph (c... procedures specified in 40 CFR 60.564(j)(1)(i). An average ethylene glycol concentration by weight shall...

  7. 40 CFR 63.1329 - Process contact cooling towers provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... high viscosity multiple end finisher process, and who is subject or becomes subject to 40 CFR part 60... operators shall follow the procedures specified in 40 CFR 60.564(j)(1), except as provided in paragraph (c... procedures specified in 40 CFR 60.564(j)(1)(i). An average ethylene glycol concentration by weight shall...

  8. 40 CFR 63.1329 - Process contact cooling towers provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... viscosity multiple end finisher process, and who is subject or becomes subject to 40 CFR part 60, subpart... existing affected source that manufactures PET using a continuous terephthalic acid high viscosity multiple... operators shall follow the procedures specified in 40 CFR 60.564(j)(1), except as provided in paragraph...

  9. 40 CFR 63.1329 - Process contact cooling towers provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... viscosity multiple end finisher process, and who is subject or becomes subject to 40 CFR part 60, subpart... existing affected source that manufactures PET using a continuous terephthalic acid high viscosity multiple... operators shall follow the procedures specified in 40 CFR 60.564(j)(1), except as provided in paragraph...

  10. A practical application for the chemical treatment of Southern California`s reclaimed, Title 22 water for use as makeup water for recirculating cooling water systems

    SciTech Connect

    Zakrzewski, J.; Cosulich, J.; Bartling, E.

    1998-12-31

    Pilot cooling water studies conducted at a Southern California landfill/cogeneration station demonstrated a successful chemical treatment program for recirculating cooling water that used unnitrified, reclaimed, Title 22 water as the primary makeup water source. The constituents in the reclaimed water are supplied by variety of residential and waste water sources resulting in a water quality that may vary to a greater degree than domestic water supplies. This water contains high concentrations of orthophosphate, ammonia, chlorides and suspended solids. The impact of which, under cycled conditions is calcium orthophosphate scaling, high corrosion of yellow metal and mild steel, stress cracking of copper alloys and stainless steel and rapidly growing biological activity. A mobile cooling water testing laboratory with two pilot recirculating water systems modeled the cogeneration station`s cooling tower operating conditions and parameters. The tube and shell, tube side cooling heat exchangers were fitted with 443 admiralty, 90/10 copper nickel, 316 stainless steel and 1202 mild steel heat exchanger tubes. Coupons and Corrater electrodes were also installed. A chemical treatment program consisting of 60/40 AA/AMPS copolymer for scale, deposits and dispersion, sodium tolyltriazole for yellow metal corrosion, and a bromination program to control the biological activity was utilized in the pilot systems. Recirculating water orthophosphate concentrations reached levels of 70 mg/L as PO, and ammonia concentrations reached levels of 35 mg/L, as total NH3. The study successfully demonstrated a chemical treatment program to control scale and deposition, minimize admiralty, 90/10 copper nickel and carbon steel corrosion rates, prevent non-heat transfer yellow metal and stainless steel stress cracking, and control the biological activity in this high nutrient water.

  11. 'Towers in the Tempest' Computer Animation Submission

    NASA Technical Reports Server (NTRS)

    Shirah, Greg

    2008-01-01

    The following describes a computer animation that has been submitted to the ACM/SIGGRAPH 2008 computer graphics conference: 'Towers in the Tempest' clearly communicates recent scientific research into how hurricanes intensify. This intensification can be caused by a phenomenon called a 'hot tower.' For the first time, research meteorologists have run complex atmospheric simulations at a very fine temporal resolution of 3 minutes. Combining this simulation data with satellite observations enables detailed study of 'hot towers.' The science of 'hot towers' is described using: satellite observation data, conceptual illustrations, and a volumetric atmospheric simulation data. The movie starts by showing a 'hot tower' observed by NASA's Tropical Rainfall Measuring Mission (TRMM) spacecraft's three dimensional precipitation radar data of Hurricane Bonnie. Next, the dynamics of a hurricane and the formation of 'hot towers' are briefly explained using conceptual illustrations. Finally, volumetric cloud, wind, and vorticity data from a supercomputer simulation of Hurricane Bonnie are shown using volume techniques such as ray marching.

  12. Applications of an MPI Enhanced Simulated Annealing Algorithm on nuSTORM and 6D Muon Cooling

    SciTech Connect

    Liu, A.

    2015-06-01

    The nuSTORM decay ring is a compact racetrack storage ring with a circumference ~480 m using large aperture ($\\phi$ = 60 cm) magnets. The design goal of the ring is to achieve a momentum acceptance of 3.8 $\\pm$10% GeV/c and a phase space acceptance of 2000 $\\mu$m·rad. The design has many challenges because the acceptance will be affected by many nonlinearity terms with large particle emittance and/or large momentum offset. In this paper, we present the application of a meta-heuristic optimization algorithm to the sextupole correction in the ring. The algorithm is capable of finding a balanced compromise among corrections of the nonlinearity terms, and finding the largest acceptance. This technique can be applied to the design of similar storage rings that store beams with wide transverse phase space and momentum spectra. We also present the recent study on the application of this algorithm to a part of the 6D muon cooling channel. The technique and the cooling concept will be applied to design a cooling channel for the extracted muon beam at nuSTORM in the future study.

  13. 1. Light tower/keeper's house and abandoned light tower, view northwest, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Light tower/keeper's house and abandoned light tower, view northwest, south southeast and east northeast sides - Matinicus Rock Light Station, Matinicus Island, on Matinicus Rock, Matinicus, Knox County, ME

  14. 2. Abandoned light tower and keeper's house/light tower, view southeast, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Abandoned light tower and keeper's house/light tower, view southeast, north northwest and west southwest sides - Matinicus Rock Light Station, Matinicus Island, on Matinicus Rock, Matinicus, Knox County, ME

  15. Integration of High-Temperature Gas-Cooled Reactors into Industrial Process Applications

    SciTech Connect

    Lee Nelson

    2011-09-01

    This report is a summary of analyses performed by the NGNP project to determine whether it is technically and economically feasible to integrate high temperature gas cooled reactor (HTGR) technology into industrial processes. To avoid an overly optimistic environmental and economic baseline for comparing nuclear integrated and conventional processes, a conservative approach was used for the assumptions and calculations.

  16. Metal foams application to enhance cooling of open cathode polymer electrolyte membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Sajid Hossain, Mohammad; Shabani, Bahman

    2015-11-01

    Conventional channel flow fields of open cathode Polymer Electrolyte Membrane Fuel Cells (PEMFCs) introduce some challenges linked to humidity, temperature, pressure and oxygen concentration gradients along the conventional flow fields that reduce the cell performance. According to previous experimental reports, with conventional air flow fields, hotspot formation due to water accumulation in Gas Diffusion Layer (GDL) is common. Unlike continuous long flow passages in conventional channels, metal foams provide randomly interrupted flow passages. Re-circulation of fluid, due to randomly distributed tortuous ligaments, enhances temperature and humidity uniformity in the fluid. Moreover, the higher electrical conductivity of metal foams compared to non-metal current collectors and their very low mass density compared to solid metal materials are expected to increase the electrical performance of the cell while significantly reducing its weight. This article reviews the existing cooling systems and identifies the important parameters on the basis of reported literature in the air cooling systems of PEMFCs. This is followed by investigating metal foams as a possible option to be used within the structure of such PEMFCs as an option that can potentially address cooling and flow distribution challenges associated with using conventional flow channels, especially in air-cooled PEMFCs.

  17. 40 CFR 463.10 - Applicability; description of the contact cooling and heating water subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) PLASTICS MOLDING AND... cooling and heating water subcategory are processes where process water comes in contact with plastic materials or plastic products for the purpose of heat transfer during plastics molding and forming....

  18. Evaluation of a Passive Heat Exchanger Based Cooling System for Fuel Cell Applications

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony J.; Burke, Kenneth A.

    2011-01-01

    Fuel cell cooling is conventionally performed with an actively controlled, dedicated coolant loop that exchanges heat with a separate external cooling loop. To simplify this system the concept of directly cooling a fuel cell utilizing a coolant loop with a regenerative heat exchanger to preheat the coolant entering the fuel cell with the coolant exiting the fuel cell was analyzed. The preheating is necessary to minimize the temperature difference across the fuel cell stack. This type of coolant system would minimize the controls needed on the coolant loop and provide a mostly passive means of cooling the fuel cell. The results indicate that an operating temperature of near or greater than 70 C is achievable with a heat exchanger effectiveness of around 90 percent. Of the heat exchanger types evaluated with the same type of fluid on the hot and cold side, a counter flow type heat exchanger would be required which has the possibility of achieving the required effectiveness. The number of heat transfer units required by the heat exchanger would be around 9 or greater. Although the analysis indicates the concept is feasible, the heat exchanger design would need to be developed and optimized for a specific fuel cell operation in order to achieve the high effectiveness value required.

  19. Optimal Inflatable Space Towers of High Height

    NASA Astrophysics Data System (ADS)

    Bolonkin, Alexander

    2002-01-01

    Author provides theory and computations for building inflatable space towers up to a hundred km in height. These towers can be used for tourism; scientific observation of space, earth's surface, weather, top atmosphere, as well as for radio, television, and communication transmissions. These towers can also be used to launch space ships and Earth satellites. These projects are not expensive and do not require rockets. They require thin strong films composed from artificial fibers and fabricated by current industry. Towers can be built using present technology. Towers can be used (for tourism, communication, etc.) during the construction process and provide self-financing for further construction. The tower design does not require work at high altitudes; all construction can be done at the earth's surface. The transport system for this tower consists a small engine (used only for friction compensation) located at the earth's surface. The tower is separated into sections and has special protection mechanism in case of a damage. Problems involving security, control, repair, and stability of the proposed towers are addressed in subsequent publications. The author is prepared to discuss these and other problems with serious organizations desiring to research and develop these projects.

  20. Optimal inflatable space towers of high height

    NASA Astrophysics Data System (ADS)

    Bolonkin, A.

    Author suggested, developed theory, and computed some projects of an optimal inflatable space tower of the heights some hundreds km. These towers can be used for tourism, scientist observation of space, Earth surface, Earth weather, Earth top atmosphere, and for radio, TV, communication transmissions. These towers can be used for launching of the space ships and Earth s atellites. The computed projects not expensive, do not request rockets. They need only in thin strong films composed from the artificial fibers and fabricated by a current industry. Towers can be built by a current technology. Towers can be explored (for tourism, communication, etc.) in a time of the construction process and give a profit, self- financing for further constriction. They can permanent increase their height. The tower design does not request a work at the high altitudes. All construction works will be making at the Earth surface. Author suggests the transport system for this tower of a high capability, which does not request a power energy issue. The small engine (only for a friction compensation) is located at the Earth surface. The tower is separated on sections and has a special protection of a case of a damage. It is considered also the problems of security, control, repair, etc. of the suggested towers. The author has also solved additional problems, which appear in these projects and which can look as difficult for the given proposal and current technology. The author is prepared to discuss the problems with serious organizations, which want to research and develop these projects.

  1. Optical design of airport control tower cabs.

    PubMed

    Carman, P D; Budde, H W

    1980-02-15

    A study has been made of optical aspects of airport control towers as part of a planned general optimization of control towers by Transport Canada. Problems found were reflections, glare, visual obstructions, identification of distant objects, and excessive solar heat. The study makes recommendations on cab shape, tower height, glazing, shades, sunglasses, binoculars, and internal lighting. Proper choice of cab shape (e.g., 30 degrees window inclination and 12-28 sides) provided effective control of reflections. Some plastic shades werefound to increase the risk of eye damage. Two tower cabs incorporating the recommendations have been built and were found to be satisfactory. PMID:20216882

  2. Large eddy simulations of turbulent flows on graphics processing units: Application to film-cooling flows

    NASA Astrophysics Data System (ADS)

    Shinn, Aaron F.

    Computational Fluid Dynamics (CFD) simulations can be very computationally expensive, especially for Large Eddy Simulations (LES) and Direct Numerical Simulations (DNS) of turbulent ows. In LES the large, energy containing eddies are resolved by the computational mesh, but the smaller (sub-grid) scales are modeled. In DNS, all scales of turbulence are resolved, including the smallest dissipative (Kolmogorov) scales. Clusters of CPUs have been the standard approach for such simulations, but an emerging approach is the use of Graphics Processing Units (GPUs), which deliver impressive computing performance compared to CPUs. Recently there has been great interest in the scientific computing community to use GPUs for general-purpose computation (such as the numerical solution of PDEs) rather than graphics rendering. To explore the use of GPUs for CFD simulations, an incompressible Navier-Stokes solver was developed for a GPU. This solver is capable of simulating unsteady laminar flows or performing a LES or DNS of turbulent ows. The Navier-Stokes equations are solved via a fractional-step method and are spatially discretized using the finite volume method on a Cartesian mesh. An immersed boundary method based on a ghost cell treatment was developed to handle flow past complex geometries. The implementation of these numerical methods had to suit the architecture of the GPU, which is designed for massive multithreading. The details of this implementation will be described, along with strategies for performance optimization. Validation of the GPU-based solver was performed for fundamental bench-mark problems, and a performance assessment indicated that the solver was over an order-of-magnitude faster compared to a CPU. The GPU-based Navier-Stokes solver was used to study film-cooling flows via Large Eddy Simulation. In modern gas turbine engines, the film-cooling method is used to protect turbine blades from hot combustion gases. Therefore, understanding the physics of

  3. Investigation of Absorption Cooling Application Powered by Solar Energy in the South Coast Region of Turkey

    NASA Astrophysics Data System (ADS)

    Babayigit, O.; Aksoy, M. H.; Ozgoren, M.; Solmaz, O.

    2013-04-01

    In this study, an absorption system using ammonia-water (NH3-H2O) solution has been theoretically examined in order to meet the cooling need of a detached building having 150 m2 floor area for Antalya, Mersin and Mugla provinces in Turkey. Hourly dynamic cooling load capacities of the building were determined by using Radiant Time Series (RTS) method in the chosen cities. For the analysis, hourly average meteorological data such as atmospheric air temperature and solar radiation belonging to the years 1998-2008 are used for performance prediction of the proposed system. Thermodynamic relations for each component of absorption cooling system is explained and coefficients of performance of the system are calculated. The maximum daily total radiation data were calculated as 7173 W/m2day on July 15, 7277 W/m2 day on July 19 and 7231 W/m2day on July 19 for Mersin, Antalya and Mugla, respectively on the 23° toward to south oriented panels from horizontal surface. The generator operating temperatures are considered between 90-130°C and the best result for 110°C is found the optimum degree for maximum coefficient of performance (COP) values at the highest solar radiation occurred time during the considered days for each province. The COP values varies between 0.521 and 0.530 for the provinces. In addition, absorber and condenser capacities and thermal efficiency for the absorption cooling system were calculated. The necessary evacuated tube collector area for the different provinces were found in the range of 45 m2 to 47 m2. It is shown that although the initial investment cost is higher for the proposed absorption cooling system, it is economically feasible because of its lower annual operation costs and can successfully be operated for the considered provinces.

  4. Airport Remote Tower Sensor Systems

    NASA Technical Reports Server (NTRS)

    Maluf, David A.; Gawdiak, Yuri; Leidichj, Christopher; Papasin, Richard; Tran, Peter B.; Bass, Kevin

    2006-01-01

    Networks of video cameras, meteorological sensors, and ancillary electronic equipment are under development in collaboration among NASA Ames Research Center, the Federal Aviation Administration (FAA), and the National Oceanic Atmospheric Administration (NOAA). These networks are to be established at and near airports to provide real-time information on local weather conditions that affect aircraft approaches and landings. The prototype network is an airport-approach-zone camera system (AAZCS), which has been deployed at San Francisco International Airport (SFO) and San Carlos Airport (SQL). The AAZCS includes remotely controlled color video cameras located on top of SFO and SQL air-traffic control towers. The cameras are controlled by the NOAA Center Weather Service Unit located at the Oakland Air Route Traffic Control Center and are accessible via a secure Web site. The AAZCS cameras can be zoomed and can be panned and tilted to cover a field of view 220 wide. The NOAA observer can see the sky condition as it is changing, thereby making possible a real-time evaluation of the conditions along the approach zones of SFO and SQL. The next-generation network, denoted a remote tower sensor system (RTSS), will soon be deployed at the Half Moon Bay Airport and a version of it will eventually be deployed at Los Angeles International Airport. In addition to remote control of video cameras via secure Web links, the RTSS offers realtime weather observations, remote sensing, portability, and a capability for deployment at remote and uninhabited sites. The RTSS can be used at airports that lack control towers, as well as at major airport hubs, to provide synthetic augmentation of vision for both local and remote operations under what would otherwise be conditions of low or even zero visibility.

  5. European Sail Tower SPS concept

    NASA Astrophysics Data System (ADS)

    Seboldt, W.; Klimke, M.; Leipold, M.; Hanowski, N.

    2001-03-01

    Based on a DLR-study in 1998/99 on behalf of ESA/ESTEC called "System Concepts, Architectures and Technologies for Space Exploration and Utilization (SE&U)" a new design for an Earth-orbiting Solar Power Satellite (SPS) has been developed. The design is called "European Sail Tower SPS" and consists mainly of deployable sail-like structures derived from the ongoing DLR/ESA solar sail technology development activity. Such a SPS satellite features an extremely light-weight and large tower-like orbital system and could supply Europe with significant amounts of electrical power generated by photovoltaic cells and subsequently transmitted to Earth via microwaves. In order to build up the sail tower, 60 units - each consisting of a pair of square-shaped sails - are moved from LEO to GEO with electric propulsion and successively assembled in GEO robotically on a central strut. Each single sail has dimensions of 150m × 150 m and is automatically deployed, using four diagonal light-weight carbon fiber (CFRP) booms which are initially rolled up on a central hub. The electric thrusters for the transport to GEO could also be used for orbit and attitude control of the assembled tower which has a total length of about 15 km and would be mainly gravity gradient stabilized. Employing thin film solar cell technology, each sail is used as a solar array and produces an electric power in orbit of about 3.7 MW e. A microwave antenna with a diameter of 1 km transmits the power to a 10 km rectenna on the ground. The total mass of this 450 MW SPS is about 2100 tons. First estimates indicate that the costs for one kWh delivered in this way could compete with present day energy costs, if launch costs would decrease by two orders of magnitude. Furthermore, mass production and large numbers of installed SPS systems must be assumed in order to lower significantly the production costs and to reduce the influence of the expensive technology development. The paper presents the technical concept

  6. Drop Tower and Aircraft Capabilities

    NASA Technical Reports Server (NTRS)

    Urban, David L.

    2015-01-01

    This presentation is a brief introduction to existing capabilities in drop towers and low-gravity aircraft that will be presented as part of a Symposium: Microgravity Platforms Other Than the ISS, From Users to Suppliers which will be a half day program to bring together the international community of gravity-dependent scientists, program officials and technologists with the suppliers of low gravity platforms (current and future) to focus on the future requirements and use of platforms other than the International Space Station (ISS).

  7. Design and fabrication of an actively cooled Langmuir probe for long pulse applications

    SciTech Connect

    Paterson, J.A.; Biagi, L.A.; Ehlers, K.W.; Koehler, G.W.

    1985-11-01

    The details of the mechanical design and fabrication for a Langmuir Probe for the continuous monitoring of plasma density are given. The probe was designed for use as a diagnostic tool in the development of long pulse positive ion plasma sources for use on neutral beam systems. The essential design feature of this probe is the incorporation of two electrically isolated cooling water circuits which actively cool the probe tip and probe jacket. The electrical isolation is required to prevent drain currents from the probe body disturbing the measurement of the probe tip current and thereby the plasma density measurement. The successful realization of the design requires precision components and vacuum tight ceramic to refractory metal brazes. To date this design has successfully operated in steady-state in plasma densities up to 250 mA/cmS and surface heat fluxes of 25 W/cmS.

  8. Spent-fuel cooling curve for safeguard applications of gross-gamma measurements

    SciTech Connect

    Rinard, P.

    1983-04-01

    Gross-gamma detectors can be used to gather data from spent-fuel assemblies in a simple and rapid manner. Using these data, inspectors can generate a power-law curve to check the consistency of the declared values with the measured values; points outside the curve indicate erroneously declared values or removal of material. Simple types of erroneously declared values can be detected immediately, whereas subtle types may require a second measurement and more subtle types may escape detection. If measurements of passive emissions of neutrons from the assemblies are made in addition to the gamma measurements, the values of the exposures and cooling times can be estimated independent of the operator-declared values. Although not yet demonstrated, it may be possible to obtain crude estimates of the exposures and cooling times from the gamma measurments alone.

  9. Combined-cycle power tower

    SciTech Connect

    Bohn, M S; Williams, T A; Price, H W

    1994-10-01

    This paper evaluates a new power tower concept that offers significant benefits for commercialization of power tower technology. The concept uses a molten nitrate salt centralreceiver plant to supply heat, in the form of combustion air preheat, to a conventional combined-cycle power plant. The evaluation focused on first commercial plants, examined three plant capacities (31, 100, and 300 MWe), and compared these plants with a solar-only 100-MWe plant and with gas-only combined-cycle plants in the same three capacities. Results of the analysis point to several benefits relative to the solar-only plant including low energy cost for first plants, low capital cost for first plants, reduced risk with respect to business uncertainties, and the potential for new markets. In addition, the concept appears to have minimal technology development requirements. Significantly, the results show that it is possible to build a first plant with this concept that can compete with existing gas-only combined-cycle plants.

  10. Meta-analysis of the effects of microclimate cooling systems on human performance under thermal stressful environments: potential applications to occupational workers.

    PubMed

    Chan, Albert P C; Song, Wenfang; Yang, Yang

    2015-01-01

    This study aims to determine the appropriate microclimate cooling systems (MCSs) to reduce heat stress and improve human performance of occupational workers and their practicality in the occupational field. Meta-analysis was employed to summarize, analyze, and compare the effects of various MCSs on human performance with corresponding physiological and psychological responses, thereby providing solid suggestions for selecting suitable MCSs for occupational workers. Wearing MCSs significantly attenuated the increases in core temperature (-0.34 °C/h) and sweating rate (-0.30 L/h), and significantly improved human performance (+29.9%, effect size [EFS] = 1.1) compared with no cooling condition (CON). Cold air-cooled garments (ACG-Cs; +106.2%, EFS = 2.32) exhibited greater effects on improving human performance among various microclimate cooling garments (MCGs), followed by liquid cooling garments (LCGs; +68.1%, EFS = 1.86) and hybrid cooling garment combining air and liquid cooling (HBCG-AL; +59.1%, EFS=3.38), natural air-cooled garments (ACG-Ns; +39.9%, EFS = 1.12), and phase change material cooling garments (PCMCGs; +19.5%, EFS = 1.2). Performance improvement was observed to be positively and linearly correlated to the differences of core temperature increase rate (r = 0.65, p < 0.01) and sweating rate (r = 0.80, p < 0.001) between MCSs and CON. Considering their application in industrial settings, ACG-Cs, LCGs, and HBCG-AL are practical for work, in which workers do not move frequently, whereas ACG-Ns and PCMCGs are more applicable for the majority of occupational workers. Further enhancement of the cooling efficiency of these two cooling strategies should be initiated. PMID:25774023

  11. Wind turbine tower for storing hydrogen and energy

    DOEpatents

    Fingersh, Lee Jay

    2008-12-30

    A wind turbine tower assembly for storing compressed gas such as hydrogen. The tower assembly includes a wind turbine having a rotor, a generator driven by the rotor, and a nacelle housing the generator. The tower assembly includes a foundation and a tubular tower with one end mounted to the foundation and another end attached to the nacelle. The tower includes an in-tower storage configured for storing a pressurized gas and defined at least in part by inner surfaces of the tower wall. In one embodiment, the tower wall is steel and has a circular cross section. The in-tower storage may be defined by first and second end caps welded to the inner surface of the tower wall or by an end cap near the top of the tower and by a sealing element attached to the tower wall adjacent the foundation, with the sealing element abutting the foundation.

  12. 98. SOUTH FRONT OF MODEL. FREESTANDING TOWER TOP AT RIGHT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    98. SOUTH FRONT OF MODEL. FREESTANDING TOWER TOP AT RIGHT REPRESENTED ALTERNATE PROPOSAL FOR NORTH TOWER TO MATCH FLAG TOWER - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  13. DETAIL OF VALVE TOWER SHOWING SLUICE GATE ON EAST SIDE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF VALVE TOWER SHOWING SLUICE GATE ON EAST SIDE OF TOWER. VIEW FACING WEST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  14. 153. Copy of Louis Rosenberg Etching (original in the Tower ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    153. Copy of Louis Rosenberg Etching (original in the Tower City Development Office, Cleveland, Ohio) TERMINAL TOWER UNDER CONSTRUCTION, PUBLIC SQUARE ELEVATION, VIEW NORTHWEST TO SOUTHEAST - Terminal Tower Building, Cleveland Union Terminal, 50 Public Square, Cleveland, Cuyahoga County, OH

  15. 158. Copy of Louis Rosenberg Etching (original in the Tower ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    158. Copy of Louis Rosenberg Etching (original in the Tower City Development Office) TERMINAL TOWER UNDER CONSTRUCTION, PUBLIC SQUARE FACADE, VIEW WEST TO EAST - Terminal Tower Building, Cleveland Union Terminal, 50 Public Square, Cleveland, Cuyahoga County, OH

  16. APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    APPROACH BRIDGE PORTION OF VALVE TOWER FOOT BRIDGE, AS SEEN FROM BELOW, SHOWING VALVE TOWER TO RIGHT. VIEW FACING NORTH - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower Foot Bridge, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  17. Passive cooling with solar updraft and evaporative downdraft chimneys

    SciTech Connect

    Mignon, G.V.; Cunningham, W.A.; Thompson, T.L.

    1985-01-01

    Computer models have been developed to describe the operation of both solar updraft and evaporative downdraft chimneys. Design studies are being conducted at the present time to use the towers for cooling an experimental, well instrumented, structure to study passive cooling in residential buildings. (MHR)

  18. Atomistic simulation of sub-nanosecond non-equilibrium field cooling processes for magnetic data storage applications

    SciTech Connect

    Evans, R. F. L.; Fan, W. J.

    2014-11-10

    Thermally assisted magnetic writing is an important technology utilizing temperature dependent magnetic properties to enable orientation of a magnetic data storage medium. Using an atomistic spin model, we study non-equilibrium field cooled magnetization processes on sub-nanosecond timescales required for device applications. We encapsulate the essential physics of the process in a thermoremanent magnetization curve and show that for fast timescales, heating to the Curie temperature is necessary where the magnetic relaxation time is shortest. Furthermore, we demonstrate the requirement for large magnetic fields to achieve a high thermoremanent magnetization necessary for fast recording or data rates.

  19. Tower Water-Vapor Mixing Ratio

    SciTech Connect

    Guastad, Krista; Riihimaki, Laura; none,

    2013-04-01

    The purpose of the Tower Water-Vapor Mixing Ratio (TWRMR) value-added product (VAP) is to calculate water-vapor mixing ratio at the 25-meter and 60-meter levels of the meteorological tower at the Southern Great Plains (SGP) Central Facility.

  20. COKE QUENCH TOWER EMISSION TESTING PROGRAM

    EPA Science Inventory

    The report gives results of a field study to further define quench tower organic emissions, the character and magnitude of which are virtually unknown. (Limited testing in 1976 indicated that a large quantity of organic material was emitted from quench towers, but these data were...

  1. 76 FR 36983 - Marking Meteorological Evaluation Towers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-24

    ... voluntary marking of METs less than 200 feet AGL (76 FR 1326). The FAA agrees that marking these structures... conspicuity of the towers for low level agricultural operations in the vicinity of these towers. FOR FURTHER... operators, associations representing agricultural operators, and state governments concerning the...

  2. An improved thermoregulatory model for cooling garment applications with transient metabolic rates

    NASA Astrophysics Data System (ADS)

    Westin, Johan K.

    Current state-of-the-art thermoregulatory models do not predict body temperatures with the accuracies that are required for the development of automatic cooling control in liquid cooling garment (LCG) systems. Automatic cooling control would be beneficial in a variety of space, aviation, military, and industrial environments for optimizing cooling efficiency, for making LCGs as portable and practical as possible, for alleviating the individual from manual cooling control, and for improving thermal comfort and cognitive performance. In this study, we adopt the Fiala thermoregulatory model, which has previously demonstrated state-of-the-art predictive abilities in air environments, for use in LCG environments. We validate the numerical formulation with analytical solutions to the bioheat equation, and find our model to be accurate and stable with a variety of different grid configurations. We then compare the thermoregulatory model's tissue temperature predictions with experimental data where individuals, equipped with an LCG, exercise according to a 700 W rectangular type activity schedule. The root mean square (RMS) deviation between the model response and the mean experimental group response is 0.16°C for the rectal temperature and 0.70°C for the mean skin temperature, which is within state-of-the-art variations. However, with a mean absolute body heat storage error 3¯ BHS of 9.7 W˙h, the model fails to satisfy the +/-6.5 W˙h accuracy that is required for the automatic LCG cooling control development. In order to improve model predictions, we modify the blood flow dynamics of the thermoregulatory model. Instead of using step responses to changing requirements, we introduce exponential responses to the muscle blood flow and the vasoconstriction command. We find that such modifications have an insignificant effect on temperature predictions. However, a new vasoconstriction dependency, i.e. the rate of change of hypothalamus temperature weighted by the

  3. Flux Sampling Errors for Aircraft and Towers

    NASA Technical Reports Server (NTRS)

    Mahrt, Larry

    1998-01-01

    Various errors and influences leading to differences between tower- and aircraft-measured fluxes are surveyed. This survey is motivated by reports in the literature that aircraft fluxes are sometimes smaller than tower-measured fluxes. Both tower and aircraft flux errors are larger with surface heterogeneity due to several independent effects. Surface heterogeneity may cause tower flux errors to increase with decreasing wind speed. Techniques to assess flux sampling error are reviewed. Such error estimates suffer various degrees of inapplicability in real geophysical time series due to nonstationarity of tower time series (or inhomogeneity of aircraft data). A new measure for nonstationarity is developed that eliminates assumptions on the form of the nonstationarity inherent in previous methods. When this nonstationarity measure becomes large, the surface energy imbalance increases sharply. Finally, strategies for obtaining adequate flux sampling using repeated aircraft passes and grid patterns are outlined.

  4. Carbon Nanotube Tower-Based Supercapacitor

    NASA Technical Reports Server (NTRS)

    Meyyappan, Meyya (Inventor)

    2012-01-01

    A supercapacitor system, including (i) first and second, spaced apart planar collectors, (ii) first and second arrays of multi-wall carbon nanotube (MWCNT) towers or single wall carbon nanotube (SWCNT) towers, serving as electrodes, that extend between the first and second collectors where the nanotube towers are grown directly on the collector surfaces without deposition of a catalyst and without deposition of a binder material on the collector surfaces, and (iii) a porous separator module having a transverse area that is substantially the same as the transverse area of at least one electrode, where (iv) at least one nanotube tower is functionalized to permit or encourage the tower to behave as a hydrophilic structure, with increased surface wettability.

  5. VALVE TOWER FROM HIGH GROUND NEAR APPROACH BRIDGE. VIEW FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VALVE TOWER FROM HIGH GROUND NEAR APPROACH BRIDGE. VIEW FACING NORTHEAST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  6. Minimization of thermal impact by application of electrode cooling in a co-linear PEF treatment chamber.

    PubMed

    Meneses, Nicolas; Jaeger, Henry; Knorr, Dietrich

    2011-10-01

    A co-linear pulsed electric field (PEF) treatment chamber was analyzed and optimized considering electrical process conditions, temperature, and retention of heat-sensitive compounds during a continuous PEF treatment of peach juice. The applicability of a jacket heat-exchanger device surrounding the ground electrode was studied in order to provide active cooling and to avoid temperature peaks within the treatment chamber thus reducing the total thermal load to which the product is exposed. Simulation of the PEF process was performed using a finite element method prior to experimental verification. Inactivation of polyphenoloxydase (PPO) and peroxidase (POD) as well as the degradation of ascorbic acid (AA) in peach juice was quantified and used as indirect indicators for the temperature distribution. Peaks of product temperature within the treatment chamber were reduced, that is, from 98 to 75 °C and retention of the indicators PPO, POD, and AA increased by more than 10% after application of the active electrode cooling device. Practical Application:  The co-linear PEF treatment chamber is widely used for continuous PEF treatment of liquid products and also suitable for industrial scale application; however, Joule heating in combination with nonuniform electric field distribution may lead to unwanted thermal effects. The proposed design showed potential to reduce the thermal load, to which the food is exposed, allowing the retention of heat-sensitive components. The design is applicable at laboratory or industrial scale to perform PEF trials avoiding temperature peaks, which is also the basis for obtaining inactivation kinetic models with minimized thermal impact on the kinetic variables. PMID:22417588

  7. Application of subgroup decomposition in diffusion theory to gas cooled thermal reactor problem

    SciTech Connect

    Yasseri, S.; Rahnema, F.

    2013-07-01

    In this paper, the accuracy and computational efficiency of the subgroup decomposition (SGD) method in diffusion theory is assessed in a ID benchmark problem characteristic of gas cooled thermal systems. This method can be viewed as a significant improvement in accuracy of standard coarse-group calculations used for VHTR whole core analysis in which core environmental effect and energy angle coupling are pronounced. It is shown that a 2-group SGD calculation reproduces fine-group (47) results with 1.5 to 6 times faster computational speed depending on the stabilizing schemes while it is as efficient as single standard 6-group diffusion calculation. (authors)

  8. The Solar lake/condensation tower system (SL/CT System)

    SciTech Connect

    deLangen, L.H.

    1983-08-01

    The system is basically an ammonia cycle between the hot water of a lake, covered with floating heat collectors and the cold air at great height of the atmosphere, only attainable by a high tower. Below, ammonia is evaporated by the water of the lake; at high level, air-cooled condensers take care of the condensation of the ammonia vapour. The system offers a possibility to be combined with a multi-stage sea-water distillation plant, enabling irrigation of deserts and steppes. In the paper attention is given to the design of the tower. Results of calculations are given about attainable energy production, quantities of building materials needed to build the tower and installations, the surface of the lake, the quantities of produced water and the surface of irrigated land.

  9. Effect of nanofluid on thermal performance of heat pipe with two evaporators; application to satellite equipment cooling

    NASA Astrophysics Data System (ADS)

    Mashaei, P. R.; Shahryari, M.

    2015-06-01

    A study on the behavior of nanofluid in a cylindrical heat pipe with two heat sources is performed to analyze the nanofluid application in heat-dissipating satellite equipment cooling. Pure water, Al2O3-water and TiO2-water nanofluids are used as working fluids. An analytical modeling is presented to predict the wall temperature profile for the heat pipe assuming saturated vapor and conduction heat transfer for porous media and wall, respectively. The effects of particle concentration levels (φ=0 (distilled water), 2, 4, and 8%), particle diameters (dp=10, 20, and 40 nm) on the local wall temperature, heat transfer coefficient, thermal resistance, and the size of the heat pipe are investigated. It is observed that the better wall temperature uniformity can be achieved using nanofluid which results in lower temperature difference between evaporators and condenser sections. Results reveal that applying nanoparticle with smaller size and higher concentration level increases heat transfer coefficient remarkably by reducing thermal resistance of saturated porous media. It is also found that the presence of nanoparticles in water can lead to a reduction in weight of heat pipe, and thus satellite, under nearly identical condition. The findings of this paper prove the potential of nanofluid in satellite equipment cooling application.

  10. Augmented Reality Tower Technology Assessment

    NASA Technical Reports Server (NTRS)

    Reisman, Ronald J.; Brown, David M.

    2009-01-01

    Augmented Reality technology may help improve Air Traffic Control Tower efficiency and safety during low-visibility conditions. This paper presents the assessments of five off-duty controllers who shadow-controlled' with an augmented reality prototype in their own facility. Initial studies indicated unanimous agreement that this technology is potentially beneficial, though the prototype used in the study was not adequate for operational use. Some controllers agreed that augmented reality technology improved situational awareness, had potential to benefit clearance, control, and coordination tasks and duties and could be very useful for acquiring aircraft and weather information, particularly aircraft location, heading, and identification. The strongest objections to the prototype used in this study were directed at aircraft registration errors, unacceptable optical transparency, insufficient display performance in sunlight, inadequate representation of the static environment and insufficient symbology.

  11. Kinetic Space Towers and Launchers

    NASA Astrophysics Data System (ADS)

    Bolonkin, A.

    The paper discusses a new revolutionary method for access to outer space. A cable stands up vertically and pulls up its payload to space with a maximum force determined by its strength. From the ground the cable is allowed to rise up to the required altitude. After this, one can climb to an altitude by this cable or deliver to altitude a required load. The paper shows this is possible and does not infringe on the law of gravity. The article contains the theory of the method and the computations for four projects for towers that are 4, 75, 225 and 160,000 km in height. The first three projects use conventional artificial fiber widely produced by current industry, while the fourth project uses nanotubes made in scientific laboratories. The paper also shows in a fifth project how this idea can be used to launch a load at high altitude.

  12. Passive generation and storage of winter ice for summer cooling applications

    SciTech Connect

    McGarity, A.E.; Gorski, A.I.

    1984-05-01

    The results of analytical and experimental work on a cooling system which uses phase-change seasonal energy storage are presented. The system uses a heat pipe to chill passively the storage medium during the winter season. During the summer, the storage medium is used as an energy sink for the cooling system of a building. The storage medium is a material that freezes at a temperature in the range 0 to 15/sup 0/C. Experiments have been performed with a prototype system using water as the storage medium at Argonne National Laboratory and large quantities of ice have been grown in an insulated tank with no use of auxiliary energy. Alternative storage materials are clathrate hydrates which freeze at temperatures above 0/sup 0/C. The use of such materials can extend the freezing season and enable the operation of the system in climates with somewhat mild winters. Here, estimates of system performance and system costs are combined to examine the economic feasibility of water-ice and clathrate hydrate systems in different climates. It is found that water-ice systems may be economically feasible in certain climates. It is also found that using a clathrate hydrate can reduce the size and cost of the heat pipe, but this cost reduction is offset by the high cost of most of the currently known clathrate forming chemicals.

  13. Elastocaloric effect of Ni-Ti wire for application in a cooling device

    NASA Astrophysics Data System (ADS)

    Tušek, J.; Engelbrecht, K.; Mikkelsen, L. P.; Pryds, N.

    2015-03-01

    We report on the elastocaloric effect of a superelastic Ni-Ti wire to be used in a cooling device. Initially, each evaluated wire was subjected to 400 loading/unloading training cycles in order to stabilize its superelastic behavior. The wires were trained at different temperatures, which lead to different stabilized superelastic behaviors. The stabilized (trained) wires were further tested isothermally (at low strain-rate) and adiabatically (at high strain-rate) at different temperatures (from 312 K to 342 K). We studied the impact of the training temperature and resulting superelastic behavior on the adiabatic temperature changes. The largest measured adiabatic temperature change during loading was 25 K with a corresponding 21 K change during unloading (at 322 K). A special focus was put on the irreversibilities in the adiabatic temperature changes between loading and unloading. It was shown that there are two sources of the temperature irreversibilities: the hysteresis (and related entropy generation) and the temporary residual strain immediately after unloading, respectively. The latter results in the temporary bending of the wire and reduced negative adiabatic temperature change. The paper also shows the impact of the applied strain on the adiabatic temperature changes as well as the distribution of the elastocaloric effect over the wire during loading in the case of two wires trained at different temperatures and the virgin wire, respectively. In the end, we propose guidelines about the required material properties for an efficient elastocaloric cooling device.

  14. Studies of Polonium Removal from Molten Lead-Bismuth for Lead-Alloy-Cooled Reactor Applications

    SciTech Connect

    Jacopo Buongiorno; Ken Czerwinski; Eric Loewen; Chris Larson

    2004-09-01

    The isotope 210Po is the main product of neutron activation in fast reactors cooled by molten lead-bismuth eutectic (LBE). The isotope 210Po is a pure alpha emitter with a half-life of 138.38 days. For typical values of the neutron flux the 210Po concentration in the coolant can reach 1-10 Ci/kg. While exposure of plant personnel to Po is prevented under normal operating conditions because the primary system is sealed, Po does pose a radiological hazard during maintenance activities for which access to submerged structures is required as well as during accidents resulting in breach of the primary-system barrier. Obviously, continuous removal of Po from the LBE reduces this hazard. Therefore, it is important to understand the mechanisms by which Po is formed in and released from the LBE. We summarize research performed at the Idaho National Engineering and Environmental Laboratory and the Massachusetts Institute of Technology to investigate the basic chemistry of four mechanisms of Po release, which could serve as the basis for a coolant cleanup system in LBE-cooled reactors. The mechanisms explored are lead polonide evaporation, formation of polonium hydride, rare-earth filtering, and alkaline extraction. For the key chemical species involved expressions are given for useful quantities such as formation energy, release, and deposition rates. It is concluded that the most promising removal mechanism is alkaline extraction, although a more systematic investigation of this mechanism is needed.

  15. Studies of Polonium Removal from Molten Lead-Bismuth for Lead-Alloy-Cooled Reactor Applications

    SciTech Connect

    Buongiorno, Jacopo; Loewen, Eric P.; Czerwinski, Kenneth; Larson, Christopher

    2004-09-15

    The isotope {sup 210}Po is the main product of neutron activation in fast reactors cooled by molten lead-bismuth eutectic (LBE). The isotope {sup 210}Po is a pure alpha emitter with a half-life of 138.38 days. For typical values of the neutron flux the {sup 210}Po concentration in the coolant can reach 1-10 Ci/kg. While exposure of plant personnel to Po is prevented under normal operating conditions because the primary system is sealed, Po does pose a radiological hazard during maintenance activities for which access to submerged structures is required as well as during accidents resulting in breach of the primary-system barrier. Obviously, continuous removal of Po from the LBE reduces this hazard. Therefore, it is important to understand the mechanisms by which Po is formed in and released from the LBE. We summarize research performed at the Idaho National Engineering and Environmental Laboratory and the Massachusetts Institute of Technology to investigate the basic chemistry of four mechanisms of Po release, which could serve as the basis for a coolant cleanup system in LBE-cooled reactors. The mechanisms explored are lead polonide evaporation, formation of polonium hydride, rare-earth filtering, and alkaline extraction. For the key chemical species involved expressions are given for useful quantities such as formation energy, release, and deposition rates. It is concluded that the most promising removal mechanism is alkaline extraction, although a more systematic investigation of this mechanism is needed.

  16. Blasting response of the Eiffel Tower

    NASA Astrophysics Data System (ADS)

    Horlyck, Lachlan; Hayes, Kieran; Caetano, Ryan; Tahmasebinia, Faham; Ansourian, Peter; Alonso-Marroquin, Fernando

    2016-08-01

    A finite element model of the Eiffel Tower was constructed using Strand7 software. The model replicates the existing tower, with dimensions justified through the use of original design drawings. A static and dynamic analysis was conducted to determine the actions of the tower under permanent, imposed and wind loadings, as well as under blast pressure loads and earthquake loads due to an explosion. It was observed that the tower utilises the full axial capacity of individual members by acting as a `truss of trusses'. As such, permanent and imposed loads are efficiently transferred to the primary columns through compression, while wind loads induce tensile forces in the windward legs and compressive forces in the leeward. Under blast loading, the tower experienced both ground vibrations and blast pressures. Ground vibrations induced a negligibly small earthquake loading into the structure which was ignored in subsequent analyses. The blast pressure was significant, and a dynamic analysis of this revealed that further research is required into the damping qualities of the structure due to soil and mechanical properties. In the worst case scenario, the blast was assumed to completely destroy several members in the adjacent leg. Despite this weakened condition, it was observed that the tower would still be able to sustain static loads, at least for enough time for occupant evacuation. Further, an optimised design revealed the structure was structurally sound under a 46% reduction of the metal tower's mass.

  17. Development of an electric field application system with transparent electrodes towards the electron EDM measurement with laser-cooled Fr atoms

    NASA Astrophysics Data System (ADS)

    Ishikawa, Taisuke; Ando, Shun; Aoki, Takahiro; Arikawa, Hiroshi; Harada, Ken-Ichi; Hayamizu, Tomohiro; Inoue, Takeshi; Itoh, Masatoshi; Kawamura, Hirokazu; Kato, Ko; Sakamoto, Kosuke; Uchiyama, Aiko; Sakemi, Yasuhiro

    2014-09-01

    The permanent electric dipole moment (EDM) of elementary particles is a good probe for new physics beyond the standard model. Since the francium (Fr) atom has a large enhancement factor of the electron EDM and laser-cooled atoms can have long coherence times, we plan to utilize laser-cooled Fr atoms for the electron EDM search experiment. Besides, a strong electric field is one of key issues for the EDM experiment. Recently, we have embarked on a development of the electric field application system with transparent electrodes coated by tin-doped indium oxide (ITO). The ITO electrodes break the difficulty in the coexistence of electrodes with several cooling laser lights. The actual electric field applied to the atom is evaluated by measuring the dc Stark shift for the laser-cooled rubidium atoms. In this presentation, the present status of the electric field application system will be reported. The permanent electric dipole moment (EDM) of elementary particles is a good probe for new physics beyond the standard model. Since the francium (Fr) atom has a large enhancement factor of the electron EDM and laser-cooled atoms can have long coherence times, we plan to utilize laser-cooled Fr atoms for the electron EDM search experiment. Besides, a strong electric field is one of key issues for the EDM experiment. Recently, we have embarked on a development of the electric field application system with transparent electrodes coated by tin-doped indium oxide (ITO). The ITO electrodes break the difficulty in the coexistence of electrodes with several cooling laser lights. The actual electric field applied to the atom is evaluated by measuring the dc Stark shift for the laser-cooled rubidium atoms. In this presentation, the present status of the electric field application system will be reported. This work is supported by Grants-in-Aid for Scientific Research (No. 26220705) and Tohoku University's Focused Research Project.

  18. Implementation of natural down-draft evaporative cooling devices in commercial buildings: The international experience

    SciTech Connect

    Chalfoun, N.V.

    1998-07-01

    Conventional evaporative coolers are high-pressure high-volume devices that deliver cool air by water evaporation wetted pads. Natural down-draft evaporative coolers, or Cool Towers, are devices developed at The University of Arizona's Environmental Research Laboratory. Similar to conventional coolers, these devices are equipped with wetted pads and sprays at the top which provide cool air by evaporation but the air is moved by gravity flow saving the energy required by the blower. In arid regions, cool towers are useful for cooling buildings and outdoor private and public areas. This paper focuses on recent implementation of cool towers in two international projects in arid regions. It also demonstrates CoolT{copyright}, a software developed by the author, which was used for sizing and designing the cool towers used in these projects. The two demonstrated projects are: (1) The Botswana Technology Center (BTC), a Headquarters office building in Bostswana, South Africa. The building energy loads were first optimized through energy conservation measures where the heating load, as predicted by computer simulation, was reduced by 89.9% and the cooling load by 24%. The cooling load was further addressed by the use of a series of integrated cool towers. (2) The Ministry of Municipal and Rural Affairs (MOMRA) Environmental Rowdah project in Riyadh, Saudi Arabia is the second, recently built, project which demonstrates the use of cool towers in outdoor spaces. The Rowdah is equipped with a 76 feet high cool tower, the biggest in the world, which provides cool air to the surrounding outdoor space. The tower performance, as predicted by the CoolT program, demonstrated that on a typical June day in Riyadh, at 3:00 p.m. the ambient air temperature of 107.1 F (41.7 C) will be cooled down to 73.9 F (23.2 C) i.e., 33.2 F (18.4 C) lower, but the 13% relative humidity of air is increased to 75% at the tower discharge.

  19. Wake characteristics of an eight-leg tower for a MOD-0 type wind turbine

    NASA Technical Reports Server (NTRS)

    Savino, J. M.; Wagner, L. H.; Sinclair, D.

    1977-01-01

    Low speed wind tunnel tests were conducted to determine the flow characteristics of the wake downwind of a 1/25th scale, all tubular eight leg tower concept suitable for application to the DOE-NASA MOD-0 wind power turbine. Measurements were made of wind speed profiles, and from these were determined the wake local minimum velocity, average velocity, and width for several wind approach angles. These data are presented herein along with tower shadow photographs and comparisons with data from an earlier lattice type, four leg tower model constructed of tubular members. Values of average wake velocity defect ratio and average ratio of wake width to blade radius for the eight leg model were estimated to be around 0.17 and 0.30, respectively, at the plane of the rotor blade. These characteristics suggest that the tower wake of the eight leg concept is slightly less than that of the four leg design.

  20. Application of differential similarity to finding nondimensional groups important in tests of cooled engine components

    NASA Technical Reports Server (NTRS)

    Sucec, J.

    1977-01-01

    The method of differential similarity is applied to the partial differential equations and boundary conditions which govern the temperature, velocity, and pressure fields in the flowing gases and the solid stationary components in air-cooled engines. This procedure yields the nondimensional groups which must have the same value in both the test rig and the engine to produce similarity between the test results and the engine performance. These results guide the experimentalist in the design and selection of test equipment that properly scales quantities to actual engine conditions. They also provide a firm fundamental foundation for substantiation of previous similarity analyses which employed heuristic, physical reasoning arguments to arrive at the nondimensional groups.

  1. Prediction of jet impingement cooling scheme characteristics (airfoil leading edge application)

    NASA Astrophysics Data System (ADS)

    Riahi, A.; Saabas, H. J.; Messeh, W. Abdel

    1993-02-01

    A control volume, finite difference method based on the work of Rhie in conjunction with a high Reynolds k-epsilon model and a two layer turbulence model was used to predict the heat transfer coefficients underneath an impinging circular jet in the absence of cross flow. The numerical results are compared to experimental measurements for two different impingement height to jet diameter ratios: H/D = 2, and H/D = 10. The comparisons indicate that, although both the k-epsilon and the two layer turbulence models are adequate in the prediction of the flow field, the two layer model resulted in heat transfer predictions that were closer to experimental observations. It was also observed that the predicted heat transfer coefficients for the case of H/D = 2 were sensitive to the assumed jet exit turbulence levels, whereas they were not for H/D = 10. This information is useful to the designer of cooled turbine components.

  2. Materials Property Profiles for Actively Cooled Panels: An Illustration for Scramjet Applications

    NASA Astrophysics Data System (ADS)

    Vermaak, N.; Valdevit, L.; Evans, A. G.

    2009-04-01

    A scheme for identifying and visualizing the material properties that limit the performance of candidate materials for actively cooled aerospace propulsion components is presented and illustrated for combustor panels for Mach 7 hypersonic vehicles. The method provides a framework for exploring the nonlinear interactions between design and materials optimization. By probing the active constraints along the border of feasible design space, the limiting properties have been elucidated for a representative group of candidate materials. Property vectors that enhance design options have also been determined. For one of the promising candidate alloys (the Ni-based superalloy, INCONEL X-750), the possibilities of reclaiming design space and lowering optimal combustor panel weight by tailoring its strength properties are assessed.

  3. Solar heating and cooling

    NASA Technical Reports Server (NTRS)

    Bartera, R. E.

    1978-01-01

    To emphasize energy conservation and low cost energy, the systems of solar heating and cooling are analyzed and compared with fossil fuel systems. The application of solar heating and cooling systems for industrial and domestic use are discussed. Topics of discussion include: solar collectors; space heating; pools and spas; domestic hot water; industrial heat less than 200 F; space cooling; industrial steam; and initial systems cost. A question and answer period is generated which closes out the discussion.

  4. High-heat-flux testing of helium-cooled heat exchangers for fusion applications

    SciTech Connect

    Youchison, D.L.; Izenson, M.G.; Baxi, C.B.; Rosenfeld, J.H.

    1996-07-01

    High-heat-flux experiments on three types of helium-cooled divertor mock-ups were performed on the 30-kW electron beam test system and its associated helium flow loop at Sandia National Laboratories. A dispersion-strengthened copper alloy (DSCu) was used in the manufacture of all the mock-ups. The first heat exchanger provides for enhanced heat transfer at relatively low flow rates and much reduced pumping requirements. The Creare sample was tested to a maximum absorbed heat flux of 5.8 MW/m{sup 2}. The second used low pressure drops and high mass flow rates to achieve good heat removal. The GA specimen was tested to a maximum absorbed heat flux of 9 MW/m{sup 2} while maintaining a surface temperature below 400{degree}C. A second experiment resulted in a maximum absorbed heat flux of 34 MW/m{sup 2} and surface temperatures near 533{degree}C. The third specimen was a DSCu, axial flow, helium-cooled divertor mock-up filled with a porous metal wick which effectively increases the available heat transfer area. Low mass flow and high pressure drop operation at 4.0 MPa were characteristic of this divertor module. It survived a maximum absorbed heat flux of 16 MW/m{sup 2} and reached a surface temperature of 740{degree}C. Thermacore also manufactured a follow-on, dual channel porous metal-type heat exchanger, which survived a maximum absorbed heat flux of 14 MW/m{sup 2} and reached a maximum surface temperature of 690{degree}C. 11refs., 20 figs., 3 tabs.

  5. FEASIBILITY OF RECOVERING USEFUL SALTS FROM IRRIGATION WASTEWATER CONCENTRATES PRODUCED BY POWER PLANT COOLING

    EPA Science Inventory

    The report evaluates the feasibility of a novel energy-conserving way to recover useful salts (sodium sulfate and calcium sulfate) from concentrated brines by evaporation/crystallization. The concentrated brines examined were cooling tower blowdown from agricultural wastewater an...

  6. Stochastic Cooling

    SciTech Connect

    Blaskiewicz, M.

    2011-01-01

    Stochastic Cooling was invented by Simon van der Meer and was demonstrated at the CERN ISR and ICE (Initial Cooling Experiment). Operational systems were developed at Fermilab and CERN. A complete theory of cooling of unbunched beams was developed, and was applied at CERN and Fermilab. Several new and existing rings employ coasting beam cooling. Bunched beam cooling was demonstrated in ICE and has been observed in several rings designed for coasting beam cooling. High energy bunched beams have proven more difficult. Signal suppression was achieved in the Tevatron, though operational cooling was not pursued at Fermilab. Longitudinal cooling was achieved in the RHIC collider. More recently a vertical cooling system in RHIC cooled both transverse dimensions via betatron coupling.

  7. Improvement to Air2Air Technology to Reduce Fresh-Water Evaporative Cooling Loss at Coal-Based Thermoelectric Power Plants

    SciTech Connect

    Ken Mortensen

    2011-12-31

    This program was undertaken to enhance the manufacturability, constructability, and cost of the Air2Air{TM} Water Conservation and Plume Abatement Cooling Tower, giving a validated cost basis and capability. Air2Air{TM} water conservation technology recovers a portion of the traditional cooling tower evaporate. The Condensing Module provides an air-to-air heat exchanger above the wet fill media, extracting the heat from the hot saturated moist air leaving in the cooling tower and condensing water. The rate of evaporate water recovery is typically 10% - 25% annually, depending on the cooling tower location (climate). This program improved the efficiency and cost of the Air2Air{TM} Water Conservation Cooling Tower capability, and led to the first commercial sale of the product, as described.

  8. A comment on towers for windmills. [structural and economic criteria

    NASA Technical Reports Server (NTRS)

    Budgen, H. P.

    1973-01-01

    Design considerations for windmill tower structures include the effects of normal wind forces on the rotor and on the tower. Circular tabular or masonry towers present a relatively simple aerodynamic solution. Economic factors establish the tubular tower as superior for small and medium sized windmills. Concrete and standard concrete block designs are cheaper than refabricated steel structures that have to be freighted.

  9. 5. View of south tower, facing northnortheast from south bank ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. View of south tower, facing north-northeast from south bank of the Columbia River. Center tower and north tower in background, lower right. - Pasco-Kennewick Transmission Line, Columbia River Crossing Towers, Columbia Drive & Gum Street, Kennewick, Benton County, WA

  10. Drop tower Beijing and short-time microgravity experiments

    NASA Astrophysics Data System (ADS)

    Wan, S. H.; Yin, M. G.; Guan, X. D.; Lin, H.; Xie, J. C.; Hu, Wen-Rui

    Beijing. At present, the drop tower is play-ing important role in the research of microgravity science and application with more effective, reliable running status.

  11. A linewidth-narrowed and frequency-stabilized dye laser for application in laser cooling of molecules.

    PubMed

    Dai, D P; Xia, Y; Yin, Y N; Yang, X X; Fang, Y F; Li, X J; Yin, J P

    2014-11-17

    We demonstrate a robust and versatile solution for locking the continuous-wave dye laser for applications in laser cooling of molecules which need linewidth-narrowed and frequency-stabilized lasers. The dye laser is first stabilized with respect to a reference cavity by Pound-Drever-Hall (PDH) technique which results in a single frequency with the linewidth 200 kHz and short-term stabilization, by stabilizing the length of the reference cavity to a stabilized helium-neon laser we simultaneously transfer the ± 2 MHz absolute frequency stability of the helium-neon laser to the dye laser with long-term stabilization. This allows the dye laser to be frequency chirped with the maximum 60 GHz scan range while its frequency remains locked. It also offers the advantages of locking at arbitrary dye laser frequencies, having a larger locking capture range and frequency scanning range to be implemented via software. This laser has been developed for the purpose of laser cooling a molecular magnesium fluoride beam. PMID:25402105

  12. Critical point wetting drop tower experiment

    NASA Technical Reports Server (NTRS)

    Kaukler, W. F.; Tcherneshoff, L. M.; Straits, S. R.

    1984-01-01

    Preliminary results for the Critical Point Wetting CPW Drop Tower Experiment are produced with immiscible systems. Much of the observed phenomena conformed to the anticipated behavior. More drops will be needed to test the CPW theory with these immiscible systems.

  13. CO2 heat pumps for commercial building applications with simultaneous heating and cooling demand

    NASA Astrophysics Data System (ADS)

    Dharkar, Supriya

    Many commercial buildings, including data centers, hotels and hospitals, have a simultaneous heating and cooling demand depending on the season, occupation and auxiliary equipment. A data center on the Purdue University, West Lafayette campus is used as a case study. The electrical equipment in data centers produce heat, which must be removed to prevent the equipment temperature from rising to a certain level. With proper integration, this heat has the potential to be used as a cost-effective energy source for heating the building in which the data center resides or the near-by buildings. The proposed heat pump system utilizes carbon dioxide with global warming potential of 1, as the refrigerant. System simulations are carried out to determine the feasibility of the system for a 12-month period. In addition, energy, environmental and economic analyses are carried out to show the benefits of this alternative technology when compared to the conventional system currently installed in the facility. Primary energy savings of ~28% to ~61%, a payback period of 3 to 4.5 years and a decrease in the environmental impact value by ~36% makes this system an attractive option. The results are then extended to other commercial buildings.

  14. Simulation of supercritical flows in rocket-motor engines: application to cooling channel and injection system

    NASA Astrophysics Data System (ADS)

    Ribert, G.; Taieb, D.; Petit, X.; Lartigue, G.; Domingo, P.

    2013-03-01

    To address physical modeling of supercritical multicomponent fluid flows, ideal-gas law must be changed to real-gas equation of state (EoS), thermodynamic and transport properties have to incorporate dense fluid corrections, and turbulence modeling has to be reconsidered compared to classical approaches. Real-gas thermodynamic is presently investigated with validation by NIST (National Institute of Standards and Technology) data. Two major issues of Liquid Rocket Engines (LRE) are also presented. The first one is the supercritical fluid flow inside small cooling channels. In a context of LRE, a strong heat flux coming from the combustion chamber (locally Φ ≈ 80 MW/m2) may lead to very steep density gradients close to the wall. These gradients have to be thermodynamically and numerically captured to properly reproduce in the simulation the mechanism of heat transfer from the wall to the fluid. This is done with a shock-capturing weighted essentially nonoscillatory (WENO) numerical discretization scheme. The second issue is a supercritical fluid injection following experimental conditions [1] in which a trans- or supercritical nitrogen is injected into warm nitrogen. The two-dimensional results show vortex structures with high fluid density detaching from the main jet and persisting in the low-speed region with low fluid density.

  15. Considerations of Alloy N for Fluoride Salt-Cooled High-Temperature Reactor Applications

    SciTech Connect

    Ren, Weiju; Muralidharan, Govindarajan; Wilson, Dane F; Holcomb, David Eugene

    2011-01-01

    Fluoride Salt-Cooled High-Temperature Reactors (FHRs) are a promising new class of thermal-spectrum nuclear reactors. The reactor structural materials must possess high-temperature strength and chemical compatibility with the liquid fluoride salt as well as with a power cycle fluid such as supercritical water while remaining resistant to residual air within the containment. Alloy N was developed for use with liquid fluoride salts and it possesses adequate strength and chemical compatibility up to about 700 C. A distinctive property of FHRs is that their maximum allowable coolant temperature is restricted by their structural alloy maximum service temperature. As the reactor thermal efficiency directly increases with the maximum coolant temperature, higher temperature resistant alloys are strongly desired. This paper reviews the current status of Alloy N and its relevance to FHRs including its design principles, development history, high temperature strength, environmental resistance, metallurgical stability, component manufacturability, ASME codification status, and reactor service requirements. The review will identify issues and provide guidance for improving the alloy properties or implementing engineering solutions.

  16. Downhole steam generator with improved preheating/cooling features. [Patent application

    DOEpatents

    Donaldson, A.B.; Hoke, D.E.; Mulac, A.J.

    1980-10-10

    An apparatus is described for downhole steam generation employing dual-stage preheaters for liquid fuel and for the water. A first heat exchange jacket for the fuel surrounds the fuel/oxidant mixing section of the combustor assembly downstream of the fuel nozzle and contacts the top of the combustor unit of the combustor assembly, thereby receiving heat directly from the combustion of the fuel/oxidant. A second stage heat exchange jacket surrounds an upper portion of the oxidant supply line adjacent the fuel nozzle receiving further heat from the compression heat which results from pressurization of the oxidant. The combustor unit includes an inner combustor sleeve whose inner wall defines the combustion zone. The inner combustor sleeve is surrounded by two concentric water channels, one defined by the space between the inner combustor sleeve and an intermediate sleeve, and the second defined by the space between the intermediate sleeve and an outer cylindrical housing. The channels are connected by an annular passage adjacent the top of the combustor assembly and the countercurrent nature of the water flow provides efficient cooling of the inner combustor sleeve. An annular water ejector with a plurality of nozzles is provided to direct water downwardly into the combustor unit at the boundary of the combustion zone and along the lower section of the intermediate sleeve.

  17. New Submount Requirement of Conductively Cooled Laser Diodes for Lidar Applications

    NASA Technical Reports Server (NTRS)

    Mo, S. Y.; Cutler, A. D.; Choi, S. H.; Lee, M. H.; Singh, U. N.

    2000-01-01

    New submount technology is essential for the development of conductively cooled high power diode laser. The simulation and experimental results indicate that thermal conductivity of submount for high power laser-diode must be at least 600 W/m/k or higher for stable operation. We have simulated several theoretical thermal model based on new submount designs and characterized high power diode lasers to determine temperature effects on the performances of laser diodes. The characterization system measures the beam power, output beam profile, temperature distribution, and spectroscopic property of high power diode laser. The characterization system is composed of four main parts: an infrared imaging camera, a CCD camera, a monochromator, and a power meter. Thermal characteristics of two commercial-grade CW 20-W diode laser bars with open heat-sink type were determined with respect to the line shift of emission spectra and beam power stability. The center wavelength of laser emission has a tendency to shift toward longer wavelength as the driving current and heat sink temperature are increased. The increase of heat sink temperature decreases the output power of the laser bar too. Such results lay the guidelines for the design of new submount for high power laser-diodes.

  18. Air-Cooled Stack Freeze Tolerance Freeze Failure Modes and Freeze Tolerance Strategies for GenDriveTM Material Handling Application Systems and Stacks Final Scientific Report

    SciTech Connect

    Hancock, David, W.

    2012-02-14

    Air-cooled stack technology offers the potential for a simpler system architecture (versus liquid-cooled) for applications below 4 kilowatts. The combined cooling and cathode air allows for a reduction in part count and hence a lower cost solution. However, efficient heat rejection challenges escalate as power and ambient temperature increase. For applications in ambient temperatures below freezing, the air-cooled approach has additional challenges associated with not overcooling the fuel cell stack. The focus of this project was freeze tolerance while maintaining all other stack and system requirements. Through this project, Plug Power advanced the state of the art in technology for air-cooled PEM fuel cell stacks and related GenDrive material handling application fuel cell systems. This was accomplished through a collaborative work plan to improve freeze tolerance and mitigate freeze-thaw effect failure modes within innovative material handling equipment fuel cell systems designed for use in freezer forklift applications. Freeze tolerance remains an area where additional research and understanding can help fuel cells to become commercially viable. This project evaluated both stack level and system level solutions to improve fuel cell stack freeze tolerance. At this time, the most cost effective solutions are at the system level. The freeze mitigation strategies developed over the course of this project could be used to drive fuel cell commercialization. The fuel cell system studied in this project was Plug Power's commercially available GenDrive platform providing battery replacement for equipment in the material handling industry. The fuel cell stacks were Ballard's commercially available FCvelocity 9SSL (9SSL) liquid-cooled PEM fuel cell stack and FCvelocity 1020ACS (Mk1020) air-cooled PEM fuel cell stack.

  19. Experimental studies of heat and mass exchange in parallel-passage rotary desiccant dehumidifiers for solar cooling applications

    NASA Astrophysics Data System (ADS)

    Bharathan, D.; Parsons, J. M.; Maclaine-Cross, I. L.

    1987-11-01

    This report presents results of work done to experimentally characterize the performance of rotary desiccant dehumidifiers and to develop and validate analytical methods for evaluating their performance in air-conditioning systems. A facility, the Cyclic Test Facility, and a test-and-analysis procedure were developed to evaluate the performance of the rotary dehumidifiers. Experiments were performed to develop a basic understanding of the simultaneous heat- and mass-transfer processes in the dehumidifiers. Two test articles were tested under cyclic operation to characterize their performance. Detailed accounts of the Cyclic Test Facility, its hardware and instrumentation, the two test articles, and data reduction and analysis methods are provided. The data provide an engineering data base for evaluating rotary desiccant dehumidifiers for cooling applications.

  20. Aerodynamic tower shake force analysis for VAWT

    SciTech Connect

    Loth, J.L.

    1985-02-01

    Vertical axis wind turbines (VAWT) are subjected to blade lift forces which vary continuously in both magnitude and direction. These blade lift forces are transmitted via the blade support arms to the tower. The resulting tower force vector is a composite of: a downwind and a crosswind average force component, rotating force vectors, and force vectors oscillating in the crosswind direction. The frequency of the rotating and oscillating forces are multiples of the product of Bw, where B is the number of blades used and ..omega.. is the rotor angular velocity. The magnitude of the largest tower shake force vector is of the same order as the average downwind force component, and may represent a serious design constraint in the calculation of the required tower stiffness. A closed-form solution for the tower force vectors has been derived, by introducing a suitable wind interference model. It shows that the magnitude of the largest tower shake force vector, using a threebladed rotor, is four times smaller than a two-bladed rotor. The Betz limit and the optimum tip speed ratio as a function of solidity has been derived by comparison with two semicylindrical actuators in series.

  1. Rock Creek Tower Painting Project : Environmental Assessment.

    SciTech Connect

    United States. Bonneville Power Administration.

    1988-10-01

    Bonneville Power Administration (BPA) built a 500-kV line across Rock Creek, a Class I trout stream about 20 miles east of Missoula, MT. Two 190-foot towers rise on either side of the Rock Creek valley, and the line between is suspended 600 feet over the valley floor. The crossing poses a hazard to passing airplanes and disrupts the natural landscape. The area where the line crosses Rock Creek is prized for its scenic beauty. In response to public demand that BPA protect the visual beauty of this area, BPA painted the towers gray to blend them best in with their natural surroundings. The issue now is to decide between either two gray towers or two orange-and-white towers. The underlying need is to resolve the conflict of pilot safety against scenic intrusion. The proposed action is to paint the gray tower aeronautical orange and white. Alternatives are to paint the orange-and-white tower back to its original gray; or leave the dilemma unresolved (the ''no-action'' alternative). 9 refs., 3 figs.

  2. Four Operational Strategies For The Tower of Pisa

    NASA Astrophysics Data System (ADS)

    Bartolozzi, F.

    The operational strategies proposed for safeguarding the Leaning Tower all agree on the urgent need to lay a sub-foundation for guaranteeing the stability of the foundation soil, considerably decreasing the current pressure to a value compatible with its resistance characteristics. Their second common property is the creation of a static beneficial effect on the material forming the monument. This effect may be achieved by reducing the pressure in the material forming the Tower, by making the present inclination decrease considerably, or by means of a reinforcement ring on the most stressed parts of the Tower - if the present inclination is to remain unchanged - or with the combined action of both the inclination decrease and the reinforcement ring. Clearly, the choice of each operation must be made within the framework of the present and particular resistance conditions of the material. On the other hand, the four techniques differ structurally and operationally. The former aspects refer to laying structural elements, all equally effective, but different in conception and function - such as pillars, beams, hinges and tubular devices ­ to be laid in order to integrate the common sub-foundation and to be utilised with respect to each operational technique. The operational differences mainly depend on the different executive needs with respect to the structural elements to be laid. The operational aspect of the fourth technique is very simple, but particularly delicate, as are all techniques concerning the Tower. In relation to this, the operation must clearly be managed by a highly qualified and professional group of technicians and workers using the most appropriate and modern technological apparatus. I believe that the considerable delicacy of the operational stage does not obstruct the application of the proposed techniques, both because of the precarious safety conditions of the building (requiring a radical solution), and because the operations put into

  3. Health-hazard evaluation report HETA 86-045-1681, 101 Marietta Tower Building, Atlanta, Georgia

    SciTech Connect

    Salisbury, S.; Roper, P.

    1986-04-01

    A reevaluation of the air quality in the Marietta Tower Building, Atlanta, Georgia was requested by the DHHS Region IV Employee Health and Safety Committee because of worker complaints about sinus problems, eye irritation, and headaches. Air cooling and circulation units were inspected on six floors. Outside air supply to these floors was measured and the buildup of carbon dioxide determined as an indicator of indoor pollution.

  4. Credit BG. View looking northeast down from the tower onto ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Credit BG. View looking northeast down from the tower onto the two horizontal test stations at Test Stand "D." Station Dy is at the far left (Dy vacuum cell out of view), with in-line exhaust gas cooling sections and steam-driven "air ejector" (or evacuator) discharging engine exhausts to the east. The Dd cell is visible at the lower left, and the Dd exhaust train has the same functions as at Dy. The spherical tank is an electrically heated "accumulator" which supplies steam to the ejectors at Dv, Dd, and Dy stations. Other large piping delivered cooling water to the horizontal train cooling sections. The horizontal duct at the "Y" branch in the Dd train connects the Dd ejector to the Dv and Cv vacuum duct system (a blank can be bolted into this duct to isolate the Dd system). The shed roof for the Dpond test station appears at bottom center of this image. The open steel frame to the lower left of the image supports a hoist and crane for installing or removing test engines from the Dd test cell - Jet Propulsion Laboratory Edwards Facility, Test Stand D, Edwards Air Force Base, Boron, Kern County, CA

  5. Cool Apps: Building Cryospheric Data Applications With Standards-Based Service Oriented Architecture

    NASA Astrophysics Data System (ADS)

    Collins, J. A.; Truslove, I.; Billingsley, B. W.; Oldenburg, J.; Brodzik, M.; Lewis, S.; Liu, M.

    2012-12-01

    The National Snow and Ice Data Center (NSIDC) holds a large collection of cryospheric data, and is involved in a number of informatics research and development projects aimed at improving the discoverability and accessibility of these data. To develop high-quality software in a timely manner, we have adopted a Service-Oriented Architecture (SOA) approach for our core technical infrastructure development. Data services at NSIDC are internally exposed to other tools and applications through standards-based service interfaces. These standards include OAI-PMH (Open Archives Initiative Protocol for Metadata Harvesting), various OGC (Open Geospatial Consortium) standards including WMS (Web Map Service) and WFS (Web Feature Service), ESIP (Federation of Earth Sciences Information Partners) OpenSearch, and NSIDC-specific RESTful services. By taking a standards-based approach, we are able to use off-the-shelf tools and libraries to consume, translate and broker these data services, and thus develop applications faster. Additionally, by exposing public interfaces to these services we provide valuable data services to technical collaborators; for example, NASA Reverb (http://reverb.echo.nasa.gov) uses NSIDC's WMS services. Our latest generation of web applications consume these data services directly. The most complete example of this is the Operation IceBridge Data Portal (http://nsidc.org/icebridge/portal) which depends on many of the aforementioned services, and clearly exhibits many of the advantages of building applications atop a service-oriented architecture. This presentation outlines the architectural approach and components and open standards and protocols adopted at NSIDC, demonstrates the interactions and uses of public and internal service interfaces currently powering applications including the IceBridge Data Portal, and outlines the benefits and challenges of this approach.

  6. Loss of coolant analysis for the tower shielding reactor 2

    SciTech Connect

    Radcliff, T.D.; Williams, P.T.

    1990-06-01

    The operational limits of the Tower Shielding Reactor-2 (TSR-2) have been revised to account for placing the reactor in a beam shield, which reduces convection cooling during a loss-of-coolant accident (LOCA). A detailed heat transfer analysis was performed to set operating time limits which preclude fuel damage during a LOCA. Since a LOCA is survivable, the pressure boundary need not be safety related, minimizing seismic and inspection requirements. Measurements of reactor component emittance for this analysis revealed that aluminum oxidized in water may have emittance much higher than accepted values, allowing higher operating limits than were originally expected. These limits could be increased further with analytical or hardware improvements. 5 refs., 7 figs.

  7. Draw tower fiber Bragg gratings and their use in sensing technology

    NASA Astrophysics Data System (ADS)

    Lindner, E.; Mörbitz, J.; Chojetzki, C.; Becker, M.; Brückner, S.; Schuster, K.; Rothhardt, M.; Bartelt, H.

    2011-06-01

    The idea of fabricating fiber Bragg gratings already during the drawing of a fiber dates back almost 20 years. The application of a transverse holographic writing method on a draw tower offers a promising solution for a highly effective Bragg grating production. Because of the high technology requirements it took more than 10 years to develop the method into a reliable process. During the last five years the improvements in the technical development enables cost effective industrial production of draw tower gratings (1DTG®). In this paper we report about new possibilities of the improved process with respect to the grating type (type I gratings, type II gratings), the coating type (2ORMOCER®, metals) and the fiber type and diameter (125μm, 80μm and below). Furthermore, we present examples for the application of draw tower fiber Bragg gratings in sensing technologies for medical applications.

  8. Energy penalty analysis of possible cooling water intake structurerequirements on existing coal-fired power plants.

    SciTech Connect

    Veil, J. A.; Littleton, D. J.; Gross, R. W.; Smith, D. N.; Parsons, E.L., Jr.; Shelton, W. W.; Feeley, T. J.; McGurl, G. V.

    2006-11-27

    Section 316(b) of the Clean Water Act requires that cooling water intake structures must reflect the best technology available for minimizing adverse environmental impact. Many existing power plants in the United States utilize once-through cooling systems to condense steam. Once-through systems withdraw large volumes (often hundreds of millions of gallons per day) of water from surface water bodies. As the water is withdrawn, fish and other aquatic organisms can be trapped against the screens or other parts of the intake structure (impingement) or if small enough, can pass through the intake structure and be transported through the cooling system to the condenser (entrainment). Both of these processes can injure or kill the organisms. EPA adopted 316(b) regulations for new facilities (Phase I) on December 18, 2001. Under the final rule, most new facilities could be expected to install recirculating cooling systems, primarily wet cooling towers. The EPA Administrator signed proposed 316(b) regulations for existing facilities (Phase II) on February 28, 2002. The lead option in this proposal would allow most existing facilities to achieve compliance without requiring them to convert once-through cooling systems to recirculating systems. However, one of the alternate options being proposed would require recirculating cooling in selected plants. EPA is considering various options to determine best technology available. Among the options under consideration are wet-cooling towers and dry-cooling towers. Both types of towers are considered to be part of recirculating cooling systems, in which the cooling water is continuously recycled from the condenser, where it absorbs heat by cooling and condensing steam, to the tower, where it rejects heat to the atmosphere before returning to the condenser. Some water is lost to evaporation (wet tower only) and other water is removed from the recirculating system as a blow down stream to control the building up of suspended and

  9. Calculations of Laminar Heat Transfer Around Cylinders of Arbitrary Cross Section and Transpiration-Cooled Walls with Application to Turbine Blade Cooling

    NASA Technical Reports Server (NTRS)

    Eckert, E R G; Livingood, J N B

    1955-01-01

    An approximate method for the development of flow and thermal boundary layers in the laminar region on cylinders with arbitrary cross section and transpiration-cooled walls is obtained by the use of Karman's integrated momentum equation and an analogous heat-flow equation. Incompressible flow with constant property values throughout the boundary layer is assumed. The velocity and temperature profiles within the boundary layer are approximated by expressions composed of trigonometric functions. Shape parameters for these profiles and functions necessary for the solution of the boundary-layer equations are presented as graphs so that the calculation for any specific case is reduced to the solution of two first-order differential equations. This method is applied to determine local heat-transfer coefficients and surface temperatures in the laminar flow region of the transpiration-cooled turbine blades for a given coolant flow rate, or to calculate the coolant flow distribution which is necessary in order to keep the blade temperature uniform along the surface.

  10. CPV semi-dense array design for dish and tower collectors

    NASA Astrophysics Data System (ADS)

    Hayden, Herb; Thomas, Paul; Fette, Nicholas; Farkas, Zoltan; Bading, Michael; Stone, Bradley; Miner, Mark; Stickroth, Oliver; Bagewadi, Nakul; Romero, Memo; Sonuparlak, Birol; Eichholz, Rainer; Ziegler, Michael; Pawlowski, Edgar

    2012-10-01

    SST is developing a new Dish CPV dense array system that overcomes the flux uniformity requirement of previous designs. The ability to operate without flux uniformity relaxes the precision requirements of primary collector optics and eliminates homogenizing optics previously required for dense array CPV. Array design can be configured for dish and tower/heliostat systems developed for thermal CSP applications. The design uses industry standard CPV cells and manufacturing materials and methods for minimum cost and high reliability. Nominal input flux to the array for full power is about 250 suns. Internal array optics increase flux to the cells to about 1200 suns. Linear optics provide additional concentration, permit novel use of commercial glass production methods and facilitate power collection design that is integrated with dynamic power conversion and maximum power point tracking (MPPT). Efficient power hybrid packaging methods are used along with advanced liquid cooling "cold-plate" thermal management. Byproduct "waste heat" can be provided for on-site CHP use. We report on the design approach and status of development with the beginning of on-sun alpha testing of the first of 50 kW of CPV modules being produced.

  11. Emerging cool white light emission from Dy(3+) doped single phase alkaline earth niobate phosphors for indoor lighting applications.

    PubMed

    Vishwakarma, Amit K; Jha, Kaushal; Jayasimhadri, M; Sivaiah, B; Gahtori, Bhasker; Haranath, D

    2015-10-21

    Single-phase cool white-light emitting BaNb2O6:Dy(3+) phosphors have been synthesized via a conventional solid-state reaction method and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) observations and spectrofluorophotometric measurements. XRD and Rietveld structural refinement studies confirm that all the samples exhibit pure orthorhombic structure [space group -C2221(20)]. SEM observations reveal the dense particle packaging with irregular morphology in a micron range. The as-prepared phosphors exhibit blue (482 nm) and yellow (574 nm) emissions under 349, 364, 386 and 399 nm excitations corresponding to (4)F9/2→(6)HJ (J = 15/2, 13/2) transitions of Dy(3+) ions. The energy transfer mechanism between Dy(3+) ions has been studied in detail and the luminescence decay lifetime for the (4)F9/2 level was found to be around 146.07 μs for the optimized phosphor composition. The calculated Commission Internationale de L'Eclairage (CIE) chromaticity coordinates for the optimized phosphor are (x = 0.322, y = 0.339), which are close to the National Television Standard Committee (NTSC) (x = 0.310, y = 0.316) coordinates. The values of CIE chromaticity coordinates and correlated color temperature (CCT) of 5907 K endorse cool white-light emission from the phosphor. The study reveals that BaNb2O6:Dy(3+) phosphor could be a potential candidate for near ultra-violet (NUV) excited white-LED applications. PMID:26374377

  12. Summary of tower designs for large horizontal axis wind turbines

    NASA Technical Reports Server (NTRS)

    Frederick, G. R.; Savino, J. M.

    1986-01-01

    Towers for large horizontal axis wind turbines, machines with a rotor axis height above 30 meters and rated at more than 500 kW, have varied in configuration, materials of construction, type of construction, height, and stiffness. For example, the U.S. large HAWTs have utilized steel truss type towers and free-standing steel cylindrical towers. In Europe, the trend has been to use only free-standing and guyed cylindrical towers, but both steel and reinforced concrete have been used as materials of construction. These variations in materials of construction and type of construction reflect different engineering approaches to the design of cost effective towers for large HAWTs. Tower designs are the NASA/DOE Mod-5B presently being fabricated. Design goals and requirements that influence tower configuration, height and materials are discussed. In particular, experiences with United States large wind turbine towers are elucidated. Finally, current trends in tower designs for large HAWTs are highlighted.

  13. Actively Cooled Ceramic Matrix Composite Concepts for High Heat Flux Applications

    NASA Technical Reports Server (NTRS)

    Eckel, Andrew J.; Jaskowiak, Martha H.; Dickens, Kevin

    2004-01-01

    High temperature composite heat exchangers are an enabling technology for a number of aeropropulsion applications. They offer the potential for mass reductions of greater than fifty percent over traditional metallics designs and enable vehicle and engine designs. Since they offer the ability to operate at significantly higher operating temperatures, they facilitate operation at reduced coolant flows and make possible temporary uncooled operation in temperature regimes, such as experienced during vehicle reentry, where traditional heat exchangers require coolant flow. This reduction in coolant requirements can translate into enhanced range or system payload. A brief review of the approaches, challenges and test results are presented, along with a status of recent government-funded projects.

  14. The Drop Tower Bremen -An Overview

    NASA Astrophysics Data System (ADS)

    von Kampen, Peter; Könemann, Thorben; Rath, Hans J.

    The Center of Applied Space Technology and Microgravity (ZARM) was founded in 1985 as an institute of the University of Bremen, which focuses on research on gravitational and space-related phenomena. In 1988, the construction of ZARM`s drop tower began. Since its inau-guration in September 1990, the eye-catching Drop Tower Bremen with a height of 146m and its characteristic glass roof has become twice a landmark on the campus of the University of Bremen and the emblem of the technology park Bremen. As such an outstanding symbol of space science in Bremen the drop tower provides an european unique facility for experiments under conditions of high-quality weightlessness with residual gravitational accelerations in the microgravity regime. The period of maximum 4.74s of each freely falling experiment at the Drop Tower Bremen is only limited by the height of the drop tower vacuum tube, which was fully manufactured of steal and enclosed by an outer concrete shell. Thus, the pure free fall height of each microgravity drop experiment is approximately 110m. By using the later in-stalled catapult system established in 2004 ZARM`s short-term microgravity laboratory is able to nearly double the time of free fall. This world-wide inimitable capsule catapult system meets scientists` demand of extending the period of weightlessness. During the catapult operation the experiment capsule performs a vertical parabolic flight within the drop tower vacuum tube. In this way the time of microgravity can be extended to slightly over 9s. Either in the drop or in the catapult operation routine the repetition rates of microgravity experiments at ZARM`s drop tower facility are the same, generally up to 3 times per day. In comparison to orbital platforms the ground-based laboratory Drop Tower Bremen represents an economic alternative with a permanent access to weightlessness on earth. Moreover, the exceptional high quality of weightlessness in order of 1e-6 g (in the frequency range below 100

  15. The recent and prospective developments of cooled IR FPAs for double application at Electron NRI

    NASA Astrophysics Data System (ADS)

    Arutunov, V. A.; Vasilyev, I. S.; Ivanov, V. G.; Prokofyev, A. E.

    2003-09-01

    The recent and prospective developments of monolithic silicon IR-Schottky-barrier staring focal plane arrays (IR SB FPAs), photodetector assembly, and digital thermal imaging cameras (TICs) at Electron National Research Institute (Electron NRI) are considered. Basic parameters for IR SB FPAs with 256x256 and 512x512 pixels, and TICs based on these arrays are presented. The problems emerged while proceeding from the developments of IR SB FPAs for the wavelength range from 3 μm to 5 μm to the developments of those ones for xLWIR range are indicated (an abrupt increase in the level of background architecture). Possibility for further improvement in basic parameters of IR SB FPAs are discussed (a decrease in threshold signal power down to 0.5-1.0"1013 W/element with an increase in quantum efficiency, a decrease in output noise and proceeding to Schottky barriers of degenerated semiconductor/silicon heterojunction, and implementation of these array parameters in photodetector assembly with improved thermal background shielding taking into consideration an optical structure of TIC for concrete application). It is concluded that relative simplicity of the technology and expected low cost of monolithic silicon IR SB FPAs with basic parameters compared with hybrid IR FPAs for the wavelength ranges from 3 μm to 5 μm and from 8 μm to 12 μm maintain large monolithic IR SB FPAs as a basis for developments of double application digital TICs in the Russian Federation.

  16. Review of state-of-the-art of solar collector corrosion processes. Task 1 of solar collector studies for solar heating and cooling applications. Final technical progress report

    SciTech Connect

    Clifford, J E; Diegle, R B

    1980-04-11

    The state-of-the-art of solar collector corrosion processes is reviewed, and Task 1 of a current research program on use of aqueous heat transfer fluids for solar heating and cooling is summarized. The review of available published literature has indicated that lack of quantitative information exists relative to collector corrosion at the present time, particularly for the higher temperature applications of solar heating and cooling compared to domestic water heating. Solar collector systems are reviewed from the corrosion/service life viewpoint, with emphasis on various applications, collector design, heat transfer fluids, and freeze protection methods. Available information (mostly qualitative) on collector corrosion technology is reviewed to indicate potential corrosion problem areas and corrosion prevention practices. Sources of limited quantitative data that are reviewed are current solar applications, research programs on collector corrosion, and pertinent experience in related applications of automotive cooling and non-solar heating and cooling. A data bank was developed to catalog corrosion information. Appendix A of this report is a bibliography of the data bank, with abstracts reproduced from presently available literature accessions (about 220). This report is presented as a descriptive summary of information that is contained in the data bank.

  17. Use of Oriented Spray Nozzles to Set the Vapor-Air Flow in Rotary Motion in the Superspray Space of the Evaporative Chimney-Type Tower

    NASA Astrophysics Data System (ADS)

    Dobrego, K. V.; Davydenko, V. F.; Koznacheev, I. A.

    2016-01-01

    The present paper considers the problem of upgrading the thermal efficiency of chimney-type evaporative cooling towers due to the rotary motion of the vapor-air flow in the superspray space. To set the vapor-air flow in rotary motion, we propose to use the momentum of the sprayed water. It has been shown that the existing parameters of spray nozzles permit setting up to 30% of the water flow momentum in translatory motion, which is enough for changing considerably the aerodynamics of the vapor-air flow in the superspray space and improving the operation of the cooling tower. The optimal angle of axial inclination of the spray cone has been estimated. Recommendations are given and problems have been posed for engineering realization of the proposed technologies in a chimney-type cooling tower.

  18. Tower Mesonetwork Climatology and Interactive Display Tool

    NASA Technical Reports Server (NTRS)

    Case, Jonathan L.; Bauman, William H., III

    2004-01-01

    Forecasters at the 45th Weather Squadron and Spaceflight Meteorology Group use data from the tower network over the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) to evaluate Launch Commit Criteria, and issue and verify forecasts for ground operations. Systematic biases in these parameters could adversely affect an analysis, forecast, or verification. Also, substantial geographical variations in temperature and wind speed can occur under specific wind directions. To address these concerns, the Applied Meteorology Unit (AMU) developed a climatology of temperatures and winds from the tower network, and identified the geographical variation and significant tower biases. The mesoclimate is largely driven by the complex land-water interfaces across KSC/CCAFS. Towers with close proximity to water typically had much warmer nocturnal temperatures and higher wind speeds throughout the year. The strongest nocturnal wind speeds occurred from October to March whereas the strongest mean daytime wind speeds occurred from February to May. These results of this project can be viewed by forecasters through an interactive graphical user interface developed by the AMU. The web-based interface includes graphical and map displays of mean, standard deviation, bias, and data availability for any combination of towers, variables, months, hours, and wind directions.

  19. Optimal Environmental Performance of Water-cooled Chiller System with All Variable Speed Configurations

    NASA Astrophysics Data System (ADS)

    Yu, Fu Wing; Chan, Kwok Tai

    This study investigates how the environmental performance of water-cooled chiller systems can be optimized by applying load-based speed control to all the system components. New chiller and cooling tower models were developed using a transient systems simulation program called TRNSYS 15 in order to assess the electricity and water consumption of a chiller plant operating for a building cooling load profile. The chiller model was calibrated using manufacturer's performance data and used to analyze the coefficient of performance when the design and control of chiller components are changed. The NTU-effectiveness approach was used for the cooling tower model to consider the heat transfer effectiveness at various air-to-water flow ratios and to identify the makeup water rate. Applying load-based speed control to the cooling tower fans and pumps could save an annual plant operating cost by around 15% relative to an equivalent system with constant speed configurations.

  20. Development of a technique to evaluate the performance of cooling headers and its applications in POSCO plate mills

    NASA Astrophysics Data System (ADS)

    Kang, Jong-Hoon; Lee, Pil-Jong

    2016-03-01

    Hundreds of thousands of liquid jet nozzles are widely used in controling cooling equipment to accelerate the cooling of hot plates. The holes of these nozzles become clogged or the hole size becomes smaller as foreign substances like grease, scrap, and mud containing cooling water are flushed through. In this case, cooling water sprays abnormally through the partially clogged or restricted nozzle. This causes inhomogeneous cooling of hot plates. The objective of this study is to develop an evaluation system of cooling headers including nozzles. This paper presents the method to evaluate the conditions of spraying nozzles. The sensor developed in this research measures the liquid column of spraying nozzles using differential pressure between the inside sensor block and ambient air. In addition, the results of a field test in a real, large factory are introduced in this paper.