Science.gov

Sample records for r407c compression air

  1. The Effect of Temperature Glide of R407C Refrigerant on the Power of Evaporator in Air Refrigerators / WPŁYW POŚLIZGU Temperatury Czynnika CHŁODNICZEGO R407C NA Moc Parownika CHŁODZIARKI Powietrza

    NASA Astrophysics Data System (ADS)

    Nowak, Bernard; Życzkowski, Piotr

    2013-12-01

    The article discusses the effect of the phenomenon of temperature glide of zeotropic refrigerants on thermal power of an evaporator in an air compression refrigerator. Zeotropic mixtures are subject to phase transitions, the process of which significantly differs from that of homogeneous refrigerants. In contrast to homogeneous refrigerants, where boiling and condensing processes take place at a constant temperature, for the zeotropic mixtures it is essential to know the vapor quality to unambiguously determine the temperature at which the evaporation process is initiated. The R407C refrigerant serves as an example to describe the method of determining the initial temperature of the evaporation process taking into account the effect of temperature glide. The developed formula (7) has been based on a proven linear course of isobars in the two-phase region (Fig. 5) and thus determining a polynomial describing their angle of inclination (8). In addition, temperature calculation formulas (9) and specific enthalpy (10) of dry saturated vapor of the R407C refrigerant have been presented as well. This approach allows to determine the temperature of the R407C refrigerant at the inlet to the evaporator without the required knowledge of its vapor quality. The previously used simplified methods for determining the temperature of a refrigerant at the inlet to the evaporator result in considerable deviations in calculated power of the evaporator compared with its actual value. The presented calculation example involving mine air compression refrigerator of TS-450P type shows that relative deviations of the evaporator thermal power may even exceed 20%. This example compares two simplified methods for determining zeotropic evaporating temperature of a refrigerant used in comparative calculations of refrigerants with the method presented in this article. W artykule przedstawiono wpływ zjawiska poślizgu temperatury zeotropowych czynników chłodniczych na moc cieplną parownika

  2. Impact of air and refrigerant maldistributions on the performance of finned-tube evaporators with R-22 and R-407C. Final Report

    SciTech Connect

    Lee, Jangho; Domanski, P.A.

    1997-07-01

    The report presents basic features of the evaporator model, EVAP5M, and simulation results for an evaporator operating with R-22 and R-407C at non-uniform air and refrigerant distributions. EVAP5M was developed under this project to provide a tool for simulating a finned-tube air-to refrigerant evaporator operating with single-component refrigerants and refrigerant mixtures. The tube-by-tube modeling approach allowed for one-dimensional non-uniformity in the air velocity profile and arbitrary maldistribution on the refrigerant side. The model uses the Carnahan-Starling-DeSantis equation of state for calculating refrigerant thermodynamic properties. Simulations were performed for three evaporator slabs with different refrigerant circuitry designs. For the maldistributions studied, maldistributed air caused much more significant capacity degradation than maldistributed refrigerant. In some cases capacity decreased to as low as 57 percent of the value obtained for uniform velocity profile. Simulation results showed that R-22 and R-407C have similar susceptibility to capacity degradation. Relative change of capacity varied depending on the evaporator design and maldistribution studied. 17 refs., 18 figs., 9 tabs.

  3. Experimental study of a R-407C drop-in test on an off-the-shelf air conditioner with a counter-cross-flow evaporator

    SciTech Connect

    Mei, V.C.; Domitrovic, R.; Chen, F.C.

    1998-03-01

    An off-the-shelf 2-ton window air conditioner having an energy efficiency ratio of 10 was used to perform a drop-in test with R-407C. Laboratory tests were performed using a parallel-cross-flow (PCF) evaporator and a counter-cross-flow (CCF) evaporator. The CCF configuration is designed to take advantage of the temperature glide of R-407C so that the warm evaporator inlet air will be in contact with the higher temperature part of the evaporator coils first. The test results indicated that, at the Air Conditioning and Refrigeration Institute-rated indoor and outdoor conditions, the cooling capacity was 8% higher and system coefficient of performance about 3.8% higher for the CCF evaporator than for the PCF evaporator. The test results also showed that the latent load for CCF was 30.6% higher than for PCF. The far better dehumidification effect provided by the CCF evaporator design is desirable for areas where the latent load is high. The experimental findings should be useful for future efforts to design a dehumidifier that uses a zeotropic refrigerant that provides a significant temperature glide. R-22 test data from a previous project are included as a reference.

  4. Performance Measurements and Mapping of a R-407C Vapor Injection Scroll Compressor

    NASA Astrophysics Data System (ADS)

    Lumpkin, Domenique; Spielbauer, Niklas; Groll, Eckhard

    2017-08-01

    Environmental conditions significantly define the performance of HVAC&R systems. Vapor compression systems in hot climates tend to operate at higher pressure ratios, leading to increased discharge temperatures. Higher discharge temperatures can lead to higher irreversibilities in the compression process, lower specific enthalpies differences across the evaporator, and possibly a reduction in the compressor life due to the breakdown of the oil used for lubrication. To counter these effects, the use of economized, vapor injection compressors is proposed for vapor compression systems in high temperature climates. Such compressors are commercially available for refrigeration applications, in particular, supermarket refrigeration systems. However, compressor maps for vapor injection compressors are limited and none exist for R-407C. Through calorimeter testing, a compressor map for a single-port vapor injection compressor using R-407C was developed. A standard correlation for mapping single-port vapor injection compressors is proposed and validated using the compressor test results. The system and compressor performance with and without vapor injection was considered. As expected, with vapor injection there was a reduction in compressor discharge temperatures and an increase in the system coefficient of performance. The proposed dimensionless correlation is more accurate than the AHRI polynomial for mapping the injection ratio, discharge temperature, and compressor heat loss. The predicted volumetric efficiency values from the dimensionless correlation is within 1% of the measured valued. Similarly, the predicted isentropic efficiency values are within 2% of the measured values.

  5. Experimental study of the speed of sound in liquid and gaseous refrigerant R-407C

    NASA Astrophysics Data System (ADS)

    Komarov, S. G.; Stankus, S. V.

    2016-01-01

    The speed of sound in liquid and gaseous refrigerant R-407C was measured by the method of ultrasonic interferometer in the temperature range from 293 to 373 K and pressure from 0.05 to 0.5 to 3.7 MPa. The experimental uncertainties of the temperature, pressure, and speed of sound measurements were estimated to be within ±20 mK, ±4 kPa, and ±(0.1-0.3) %, respectively. The obtained results are compared with the calculated speed of sound from the fundamental state equation for the Helmholtz free energy.

  6. Drying R-407C and R-410A refrigerant blends with molecular sieve desiccants

    SciTech Connect

    Cohen, A.P.; Tucker, D.M.

    1998-10-01

    The hydrofluorocarbon (HFC) R-32 (CF{sub 2}H{sub 2}) is a component of refrigerant blends in the 407 and 410 series being tested and commercialized for use as replacements for R-502 and the hydrochlorofluorocarbon (HCFC) R-22. The molecular sieve desiccants used with chlorofluorocarbon (CFC) and HCFC mineral oil systems in the past have achieved high water capacity by excluding the refrigerant and adsorbing only the water. Unfortunately, R-32 is adsorbed on commercial type 3A molecular sieve desiccant products. The result of this adsorption is a loss of water capacity when drying R-32 compared to drying R-22 or R-502 and a reduced level of chemical compatibility of the desiccant with the refrigerant. Some compressor manufacturers are seeking a water concentration as low as 10 mg/kg (ppm[wt]) in the circulating refrigerant of polyolester-lubricated refrigerating equipment using these HFC blends. This paper compares unmodified commercial type 3A molecular sieve desiccants with a recently developed, modified 3A molecular sieve that excludes R-32. The modified 3A has better chemical compatibility with R-32 and high water capacity in liquid R-407C and R-410A. The drying rates of the two desiccants in R-407C and R-410A are similar. Data and test methods are reported on refrigerant adsorption, water capacity, drying rate, and chemical compatibility.

  7. Dental Compressed Air Systems.

    DTIC Science & Technology

    1992-03-01

    I AL-TR-IWI-0uuu AD-A249 954 DENTAL COMPRESSED AIMYTM R Curtis D. Weyrmuch, Mejor, USAP, D Samuel P.Dvs iueatclpi SF.O N AEROSPACE MwaEDIN mwr~ComA G...FUNDING NUMBERS Dental Compressed Air Systems PE - 87714F PR - 7350 TA - 22 D. Weyrauch WU - XX Samuel P. Davis George W. Gaines 7. PERFORMING...words) The purpose of this report is to update guidelines on dental compressed air systems (DCA). Much of the information was obtained from a survey

  8. Compressed air energy storage system

    DOEpatents

    Ahrens, Frederick W.; Kartsounes, George T.

    1981-01-01

    An internal combustion reciprocating engine is operable as a compressor during slack demand periods utilizing excess power from a power grid to charge air into an air storage reservoir and as an expander during peak demand periods to feed power into the power grid utilizing air obtained from the air storage reservoir together with combustible fuel. Preferably the internal combustion reciprocating engine is operated at high pressure and a low pressure turbine and compressor are also employed for air compression and power generation.

  9. Compressed air energy storage system

    DOEpatents

    Ahrens, F.W.; Kartsounes, G.T.

    An internal combustion reciprocating engine is operable as a compressor during slack demand periods utilizing excess power from a power grid to charge air into an air storage reservoir and as an expander during peak demand periods to feed power into the power grid utilizing air obtained from the air storage reservoir together with combustion reciprocating engine is operated at high pressure and a low pressure turbine and compressor are also employed for air compression and power generation.

  10. 29 CFR 1917.154 - Compressed air.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Compressed air. 1917.154 Section 1917.154 Labor Regulations...) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.154 Compressed air. Employees shall be... this part during cleaning with compressed air. Compressed air used for cleaning shall not exceed...

  11. 29 CFR 1917.154 - Compressed air.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Compressed air. 1917.154 Section 1917.154 Labor Regulations...) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.154 Compressed air. Employees shall be... this part during cleaning with compressed air. Compressed air used for cleaning shall not exceed...

  12. 29 CFR 1917.154 - Compressed air.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Compressed air. 1917.154 Section 1917.154 Labor Regulations...) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.154 Compressed air. Employees shall be... this part during cleaning with compressed air. Compressed air used for cleaning shall not exceed...

  13. 29 CFR 1917.154 - Compressed air.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Compressed air. 1917.154 Section 1917.154 Labor Regulations...) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.154 Compressed air. Employees shall be... this part during cleaning with compressed air. Compressed air used for cleaning shall not exceed...

  14. 29 CFR 1917.154 - Compressed air.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Compressed air. 1917.154 Section 1917.154 Labor Regulations...) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.154 Compressed air. Employees shall be... this part during cleaning with compressed air. Compressed air used for cleaning shall not exceed...

  15. 30 CFR 75.1730 - Compressed air; general; compressed air systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compressed air; general; compressed air systems... Compressed air; general; compressed air systems. (a) All pressure vessels shall be constructed, installed... Safety and Health district office. (b) Compressors and compressed-air receivers shall be equipped...

  16. 30 CFR 75.1730 - Compressed air; general; compressed air systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Compressed air; general; compressed air systems... Compressed air; general; compressed air systems. (a) All pressure vessels shall be constructed, installed... Safety and Health district office. (b) Compressors and compressed-air receivers shall be equipped...

  17. 30 CFR 75.1730 - Compressed air; general; compressed air systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Compressed air; general; compressed air systems... Compressed air; general; compressed air systems. (a) All pressure vessels shall be constructed, installed... Safety and Health district office. (b) Compressors and compressed-air receivers shall be equipped...

  18. 30 CFR 75.1730 - Compressed air; general; compressed air systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Compressed air; general; compressed air systems... Compressed air; general; compressed air systems. (a) All pressure vessels shall be constructed, installed... Safety and Health district office. (b) Compressors and compressed-air receivers shall be equipped...

  19. 30 CFR 75.1730 - Compressed air; general; compressed air systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Compressed air; general; compressed air systems... Compressed air; general; compressed air systems. (a) All pressure vessels shall be constructed, installed... Safety and Health district office. (b) Compressors and compressed-air receivers shall be equipped...

  20. Chapter 22: Compressed Air Evaluation Protocol

    SciTech Connect

    Benton, N.

    2014-11-01

    Compressed-air systems are used widely throughout industry for many operations, including pneumatic tools, packaging and automation equipment, conveyors, and other industrial process operations. Compressed-air systems are defined as a group of subsystems composed of air compressors, air treatment equipment, controls, piping, pneumatic tools, pneumatically powered machinery, and process applications using compressed air. A compressed-air system has three primary functional subsystems: supply, distribution, and demand. Air compressors are the primary energy consumers in a compressed-air system and are the primary focus of this protocol. The two compressed-air energy efficiency measures specifically addressed in this protocol are: high-efficiency/variable speed drive (VSD) compressor replacing modulating compressor; compressed-air leak survey and repairs. This protocol provides direction on how to reliably verify savings from these two measures using a consistent approach for each.

  1. Industrial Compressed Air System Energy Efficiency Guidebook.

    SciTech Connect

    United States. Bonneville Power Administration.

    1993-12-01

    Energy efficient design, operation and maintenance of compressed air systems in industrial plants can provide substantial reductions in electric power and other operational costs. This guidebook will help identify cost effective, energy efficiency opportunities in compressed air system design, re-design, operation and maintenance. The guidebook provides: (1) a broad overview of industrial compressed air systems, (2) methods for estimating compressed air consumption and projected air savings, (3) a description of applicable, generic energy conservation measures, and, (4) a review of some compressed air system demonstration projects that have taken place over the last two years. The primary audience for this guidebook includes plant maintenance supervisors, plant engineers, plant managers and others interested in energy management of industrial compressed air systems.

  2. Seneca Compressed Air Energy Storage (CAES) Project

    SciTech Connect

    2012-11-30

    This document provides specifications for the process air compressor for a compressed air storage project, requests a budgetary quote, and provides supporting information, including compressor data, site specific data, water analysis, and Seneca CAES value drivers.

  3. Recoil Experiments Using a Compressed Air Cannon

    ERIC Educational Resources Information Center

    Taylor, Brett

    2006-01-01

    Ping-Pong vacuum cannons, potato guns, and compressed air cannons are popular and dramatic demonstrations for lecture and lab. Students enjoy them for the spectacle, but they can also be used effectively to teach physics. Recently we have used a student-built compressed air cannon as a laboratory activity to investigate impulse, conservation of…

  4. Recoil Experiments Using a Compressed Air Cannon

    ERIC Educational Resources Information Center

    Taylor, Brett

    2006-01-01

    Ping-Pong vacuum cannons, potato guns, and compressed air cannons are popular and dramatic demonstrations for lecture and lab. Students enjoy them for the spectacle, but they can also be used effectively to teach physics. Recently we have used a student-built compressed air cannon as a laboratory activity to investigate impulse, conservation of…

  5. Compressed Air/Vacuum Transportation Techniques

    NASA Astrophysics Data System (ADS)

    Guha, Shyamal

    2011-03-01

    General theory of compressed air/vacuum transportation will be presented. In this transportation, a vehicle (such as an automobile or a rail car) is powered either by compressed air or by air at near vacuum pressure. Four version of such transportation is feasible. In all versions, a ``c-shaped'' plastic or ceramic pipe lies buried a few inches under the ground surface. This pipe carries compressed air or air at near vacuum pressure. In type I transportation, a vehicle draws compressed air (or vacuum) from this buried pipe. Using turbine or reciprocating air cylinder, mechanical power is generated from compressed air (or from vacuum). This mechanical power transferred to the wheels of an automobile (or a rail car) drives the vehicle. In type II-IV transportation techniques, a horizontal force is generated inside the plastic (or ceramic) pipe. A set of vertical and horizontal steel bars is used to transmit this force to the automobile on the road (or to a rail car on rail track). The proposed transportation system has following merits: virtually accident free; highly energy efficient; pollution free and it will not contribute to carbon dioxide emission. Some developmental work on this transportation will be needed before it can be used by the traveling public. The entire transportation system could be computer controlled.

  6. 30 CFR 56.13020 - Use of compressed air.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Use of compressed air. 56.13020 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13020 Use of compressed air. At no time shall compressed air be directed toward a...

  7. 30 CFR 56.13020 - Use of compressed air.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Use of compressed air. 56.13020 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13020 Use of compressed air. At no time shall compressed air be directed toward a...

  8. 30 CFR 77.412 - Compressed air systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Compressed air systems. 77.412 Section 77.412... for Mechanical Equipment § 77.412 Compressed air systems. (a) Compressors and compressed-air receivers... involving the pressure system of compressors, receivers, or compressed-air-powered equipment shall not...

  9. 30 CFR 56.13020 - Use of compressed air.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Use of compressed air. 56.13020 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13020 Use of compressed air. At no time shall compressed air be directed toward a...

  10. 30 CFR 57.13020 - Use of compressed air.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Use of compressed air. 57.13020 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13020 Use of compressed air. At no time shall compressed air be directed toward...

  11. 30 CFR 57.13020 - Use of compressed air.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Use of compressed air. 57.13020 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13020 Use of compressed air. At no time shall compressed air be directed toward a...

  12. 30 CFR 77.412 - Compressed air systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Compressed air systems. 77.412 Section 77.412... for Mechanical Equipment § 77.412 Compressed air systems. (a) Compressors and compressed-air receivers... involving the pressure system of compressors, receivers, or compressed-air-powered equipment shall not be...

  13. 30 CFR 77.412 - Compressed air systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... involving the pressure system of compressors, receivers, or compressed-air-powered equipment shall not be... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compressed air systems. 77.412 Section 77.412... for Mechanical Equipment § 77.412 Compressed air systems. (a) Compressors and compressed-air receivers...

  14. Positive Displacement Compressor Technology for Air Congitioners

    NASA Astrophysics Data System (ADS)

    Nagatomo, Shigemi

    Trends of compressor technologies for air conditioners are presented in this paper. HFC refrigerants such is R410A and R407C are promising candidates as an alternative for R22. Performance of rotary and scroll compressors in the operation with R410A and R407C are described. In addition, compressor technologies such as efficiency improvement, reliability and simulation methods are described in both cases of rotary and scroll compressors. Advanced compressor technologies developed for air conditioners are desired in the field of the global environment protection and the energy saving.

  15. Compressible Flow Tables for Air

    NASA Technical Reports Server (NTRS)

    Burcher, Marie A.

    1947-01-01

    This paper contains a tabulation of functions of the Mach number which are frequently used in high-speed aerodynamics. The tables extend from M = 0 to M = 10.0 in increments of 0.01 and are based on the assumption that air is a perfect gas having a specific heat ratio of 1.400.

  16. Efficiency at Sorting Cards in Compressed Air

    PubMed Central

    Poulton, E. C.; Catton, M. J.; Carpenter, A.

    1964-01-01

    At a site where compressed air was being used in the construction of a tunnel, 34 men sorted cards twice, once at normal atmospheric pressure and once at 3½, 2½, or 2 atmospheres absolute pressure. An additional six men sorted cards twice at normal atmospheric pressure. When the task was carried out for the first time, all the groups of men performing at raised pressure were found to yield a reliably greater proportion of very slow responses than the group of men performing at normal pressure. There was reliably more variability in timing at 3½ and 2½ atmospheres absolute than at normal pressure. At 3½ atmospheres absolute the average performance was also reliably slower. When the task was carried out for the second time, exposure to 3½ atmospheres absolute pressure had no reliable effect. Thus compressed air affected performance only while the task was being learnt; it had little effect after practice. No reliable differences were found related to age, to length of experience in compressed air, or to the duration of the exposure to compressed air, which was never less than 10 minutes at 3½ atmospheres absolute pressure. PMID:14180485

  17. 30 CFR 77.412 - Compressed air systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for Mechanical Equipment § 77.412 Compressed air systems. (a) Compressors and compressed-air receivers... used at connections to machines of high-pressure hose lines of 1-inch inside diameter or larger,...

  18. 41 CFR 50-204.8 - Use of compressed air.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 1 2012-07-01 2009-07-01 true Use of compressed air. 50-204.8 Section 50-204.8 Public Contracts and Property Management Other Provisions Relating to Public... General Safety and Health Standards § 50-204.8 Use of compressed air. Compressed air shall not be used...

  19. 41 CFR 50-204.8 - Use of compressed air.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Use of compressed air. 50-204.8 Section 50-204.8 Public Contracts and Property Management Other Provisions Relating to Public... General Safety and Health Standards § 50-204.8 Use of compressed air. Compressed air shall not be used...

  20. 41 CFR 50-204.8 - Use of compressed air.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 1 2013-07-01 2013-07-01 false Use of compressed air. 50-204.8 Section 50-204.8 Public Contracts and Property Management Other Provisions Relating to... CONTRACTS General Safety and Health Standards § 50-204.8 Use of compressed air. Compressed air shall not...

  1. 41 CFR 50-204.8 - Use of compressed air.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 1 2014-07-01 2014-07-01 false Use of compressed air. 50-204.8 Section 50-204.8 Public Contracts and Property Management Other Provisions Relating to... CONTRACTS General Safety and Health Standards § 50-204.8 Use of compressed air. Compressed air shall not...

  2. Recoil Experiments Using a Compressed Air Cannon

    NASA Astrophysics Data System (ADS)

    Taylor, Brett

    2006-12-01

    Ping-Pong vacuum cannons, potato guns, and compressed air cannons are popular and dramatic demonstrations for lecture and lab.1-3 Students enjoy them for the spectacle, but they can also be used effectively to teach physics. Recently we have used a student-built compressed air cannon as a laboratory activity to investigate impulse, conservation of momentum, and kinematics. It is possible to use the cannon, along with the output from an electronic force plate, as the basis for many other experiments in the laboratory. In this paper, we will discuss the recoil experiment done by our students in the lab and also mention a few other possibilities that this apparatus could be used for.

  3. Compressed air energy storage technology program

    NASA Astrophysics Data System (ADS)

    Loscutoff, W. V.

    1980-06-01

    Progress in the development of compressed air energy storage (CAES) technologies for central station electric utility applications is reported. It is reported that the concept improves the effectiveness of a gas turbine using petroleum fuels, could reduce petroleum fuel consumption of electric utility peaking plants, and is technically feasible and economically viable. Specific topics discussed include stability criteria for large underground reservoirs in salt domes, hard rock, and porous rock used for air storage in utility applications and second-generation technologies that have minimal or no dependence on petroleum fuels. The latter includes integration of thermal energy storage, fluidized bed combustion, or coal gasification with CAES.

  4. University of Arizona Compressed Air Energy Storage

    SciTech Connect

    Simmons, Joseph; Muralidharan, Krishna

    2012-12-31

    Boiled down to its essentials, the grant’s purpose was to develop and demonstrate the viability of compressed air energy storage (CAES) for use in renewable energy development. While everyone agrees that energy storage is the key component to enable widespread adoption of renewable energy sources, the development of a viable scalable technology has been missing. The Department of Energy has focused on expanded battery research and improved forecasting, and the utilities have deployed renewable energy resources only to the extent of satisfying Renewable Portfolio Standards. The lack of dispatchability of solar and wind-based electricity generation has drastically increased the cost of operation with these components. It is now clear that energy storage coupled with accurate solar and wind forecasting make up the only combination that can succeed in dispatchable renewable energy resources. Conventional batteries scale linearly in size, so the price becomes a barrier for large systems. Flow batteries scale sub-linearly and promise to be useful if their performance can be shown to provide sufficient support for solar and wind-base electricity generation resources. Compressed air energy storage provides the most desirable answer in terms of scalability and performance in all areas except efficiency. With the support of the DOE, Tucson Electric Power and Science Foundation Arizona, the Arizona Research Institute for Solar Energy (AzRISE) at the University of Arizona has had the opportunity to investigate CAES as a potential energy storage resource.

  5. Microfluidic pressure sensing using trapped air compression.

    PubMed

    Srivastava, Nimisha; Burns, Mark A

    2007-05-01

    We have developed a microfluidic method for measuring the fluid pressure head experienced at any location inside a microchannel. The principal component is a microfabricated sealed chamber with a single inlet and no exit; the entrance to the single inlet is positioned at the location where pressure is to be measured. The pressure measurement is then based on monitoring the movement of a liquid-air interface as it compresses air trapped inside the microfabricated sealed chamber and calculating the pressure using the ideal gas law. The method has been used to measure the pressure of the air stream and continuous liquid flow inside microfluidic channels (d approximately 50 microm). Further, a pressure drop has also been measured using multiple microfabricated sealed chambers. For air pressure, a resolution of 700 Pa within a full-scale range of 700-100 kPa was obtained. For liquids, pressure drops as low as 70 Pa were obtained in an operating range from 70 Pa to 10 kPa. Since the method primarily uses a microfluidic sealed chamber, it does not require additional fabrication steps and may easily be incorporated in several lab-on-a-chip fluidic applications for laminar as well as turbulent flow conditions.

  6. Microfluidic pressure sensing using trapped air compression

    PubMed Central

    Srivastava, Nimisha; Burns, Mark A.

    2010-01-01

    We have developed a microfluidic method for measuring the fluid pressure head experienced at any location inside a microchannel. The principal component is a microfabricated sealed chamber with a single inlet and no exit; the entrance to the single inlet is positioned at the location where pressure is to be measured. The pressure measurement is then based on monitoring the movement of a liquid–air interface as it compresses air trapped inside the microfabricated sealed chamber and calculating the pressure using the ideal gas law. The method has been used to measure the pressure of the air stream and continuous liquid flow inside microfluidic channels (d ~ 50 μm). Further, a pressure drop has also been measured using multiple microfabricated sealed chambers. For air pressure, a resolution of 700 Pa within a full-scale range of 700–100 kPa was obtained. For liquids, pressure drops as low as 70 Pa were obtained in an operating range from 70 Pa to 10 kPa. Since the method primarily uses a microfluidic sealed chamber, it does not require additional fabrication steps and may easily be incorporated in several lab-on-a-chip fluidic applications for laminar as well as turbulent flow conditions. PMID:17476384

  7. Assessment of the market for compressed air services

    SciTech Connect

    None, None

    2001-01-01

    The objective of this report is to provide a comprehensive and balanced view of the market for engineering and consulting services to improve the energy efficiency of plant compressed air systems. The report is intended for use by Compressed Air Challenge and other industrial energy efficiency program operators in developing strategies to encourage the growth of the compressed air system efficiency and enhance the quality of the services it offers.

  8. Fuel-Free Compressed-Air Energy Storage: Fuel-Free, Ubiquitous Compressed-Air Energy Storage and Power Conditioning

    SciTech Connect

    2010-09-13

    GRIDS Project: General Compression has developed a transformative, near-isothermal compressed air energy storage system (GCAES) that prevents air from heating up during compression and cooling down during expansion. When integrated with renewable generation, such as a wind farm, intermittent energy can be stored in compressed air in salt caverns or pressurized tanks. When electricity is needed, the process is reversed and the compressed air is expanded to produce electricity. Unlike conventional compressed air energy storage (CAES) projects, no gas is burned to convert the stored high-pressure air back into electricity. The result of this breakthrough is an ultra-efficient, fully shapeable, 100% renewable and carbon-free power product. The GCAES™ system can provide high quality electricity and ancillary services by effectively integrating renewables onto the grid at a cost that is competitive with gas, coal and nuclear generation.

  9. Seneca Compressed Air Energy Storage (CAES) Project

    SciTech Connect

    None, None

    2012-11-30

    This report provides a review and an analysis of potential environmental justice areas that could be affected by the New York State Electric & Gas (NYSEG) compress air energy storage (CAES) project and identifies existing environmental burden conditions on the area and evaluates additional burden of any significant adverse environmental impact. The review assesses the socioeconomic and demographic conditions of the area surrounding the proposed CAES facility in Schuyler County, New York. Schuyler County is one of 62 counties in New York. Schuyler County’s 2010 population of 18,343 makes it one of the least populated counties in the State (U.S. Census Bureau, 2010). This report was prepared for WorleyParsons by ERM and describes the study area investigated, methods and criteria used to evaluate this area, and the findings and conclusions from the evaluation.

  10. 78. PIPING CHANNEL FOR FUEL LOADING, FUEL TOPPING, COMPRESSED AIR, ...

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

    78. PIPING CHANNEL FOR FUEL LOADING, FUEL TOPPING, COMPRESSED AIR, GASEOUS NITROGEN, AND HELIUM - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  11. 6. DETAIL OF HIGHPRESSURE COMPRESSED AIR HOSE IN SOUTHWEST CORNER ...

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

    6. DETAIL OF HIGH-PRESSURE COMPRESSED AIR HOSE IN SOUTHWEST CORNER OF SHIPPING AND RECEIVING ROOM (109) - Vandenberg Air Force Base, Space Launch Complex 3, Vehicle Support Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  12. Working Characteristics of Variable Intake Valve in Compressed Air Engine

    PubMed Central

    Yu, Qihui; Shi, Yan; Cai, Maolin

    2014-01-01

    A new camless compressed air engine is proposed, which can make the compressed air energy reasonably distributed. Through analysis of the camless compressed air engine, a mathematical model of the working processes was set up. Using the software MATLAB/Simulink for simulation, the pressure, temperature, and air mass of the cylinder were obtained. In order to verify the accuracy of the mathematical model, the experiments were conducted. Moreover, performance analysis was introduced to design compressed air engine. Results show that, firstly, the simulation results have good consistency with the experimental results. Secondly, under different intake pressures, the highest output power is obtained when the crank speed reaches 500 rpm, which also provides the maximum output torque. Finally, higher energy utilization efficiency can be obtained at the lower speed, intake pressure, and valve duration angle. This research can refer to the design of the camless valve of compressed air engine. PMID:25379536

  13. Working characteristics of variable intake valve in compressed air engine.

    PubMed

    Yu, Qihui; Shi, Yan; Cai, Maolin

    2014-01-01

    A new camless compressed air engine is proposed, which can make the compressed air energy reasonably distributed. Through analysis of the camless compressed air engine, a mathematical model of the working processes was set up. Using the software MATLAB/Simulink for simulation, the pressure, temperature, and air mass of the cylinder were obtained. In order to verify the accuracy of the mathematical model, the experiments were conducted. Moreover, performance analysis was introduced to design compressed air engine. Results show that, firstly, the simulation results have good consistency with the experimental results. Secondly, under different intake pressures, the highest output power is obtained when the crank speed reaches 500 rpm, which also provides the maximum output torque. Finally, higher energy utilization efficiency can be obtained at the lower speed, intake pressure, and valve duration angle. This research can refer to the design of the camless valve of compressed air engine.

  14. 46 CFR 112.50-7 - Compressed air starting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-7 Compressed air starting. A compressed air starting system must meet the following: (a) The starting, charging... system must provide the cranking torque and engine starting RPM recommended by the engine manufacturer...

  15. 30 CFR 77.411 - Compressed air and boilers; general.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compressed air and boilers; general. 77.411... COAL MINES Safeguards for Mechanical Equipment § 77.411 Compressed air and boilers; general. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance with...

  16. 30 CFR 77.411 - Compressed air and boilers; general.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Compressed air and boilers; general. 77.411... COAL MINES Safeguards for Mechanical Equipment § 77.411 Compressed air and boilers; general. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance with...

  17. 30 CFR 77.411 - Compressed air and boilers; general.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Compressed air and boilers; general. 77.411... COAL MINES Safeguards for Mechanical Equipment § 77.411 Compressed air and boilers; general. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance with...

  18. 30 CFR 77.411 - Compressed air and boilers; general.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Compressed air and boilers; general. 77.411... COAL MINES Safeguards for Mechanical Equipment § 77.411 Compressed air and boilers; general. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance with...

  19. 30 CFR 77.411 - Compressed air and boilers; general.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Compressed air and boilers; general. 77.411... COAL MINES Safeguards for Mechanical Equipment § 77.411 Compressed air and boilers; general. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance with...

  20. Energy storage by compressed air. [using windpowered pumps

    NASA Technical Reports Server (NTRS)

    Szego, G. C.

    1973-01-01

    The feasibility of windpower energy storage by compressed air is considered. The system is comprised of a compressor, a motor, and a pump turbine to store air in caverns or aquifiers. It is proposed that storage of several days worth of compressed air up to 650 pounds per square inch can be used to push the aquifier up closer to the container dome and thus initiate piston action by simply compressing air more and more. More energy can be put into it by pressure increase or pushing back the water in the aquifier. This storage system concept has reheat flexibility and lowest cost effectiveness.

  1. Experiments on a compressed air loudspeaker

    NASA Astrophysics Data System (ADS)

    Glendinning, A. G.; Nelson, P. A.; Elliott, S. J.

    1990-05-01

    This work describes the development, construction, theoretical analysis and experimental evaluation of a novel type of electropneumatic sound source. The source has been specifically developed with a view to its application in active noise control systems applied in hostile environments, such as those found in the exhaust systems of gas turbines and internal combustion engines. This need arises in view of the relative fragility and large physical size of conventional loudspeakers and the high degree of non-linearity of existing electropneumatic transducers. In the new design a gas bearing is used to support the friction free motion of a sliding plate which is used to modulate the supply of compressed air. The sliding plate is driven by an electrodynamic vibrator. Experimental results demonstrate that this arrangement reduces harmonic distortion to at least 20 dB below the fundamental driving frequency for most operating conditions. In a companion paper a theoretical analysis of the transducer is presented by Chapman and Glendinning which enables predictions to be made of the acoustic volume velocity (source strength) produced by the transducer as a function of the upstream pressure and displacement of the sliding valve. The predictions of this theoretical model are found to be in good agreement with experimental results.

  2. Seneca Compressed Air Energy Storage (CAES) Project

    SciTech Connect

    None, None

    2012-11-30

    Compressed Air Energy Storage (CAES) is a hybrid energy storage and generation concept that has many potential benefits especially in a location with increasing percentages of intermittent wind energy generation. The objectives of the NYSEG Seneca CAES Project included: for Phase 1, development of a Front End Engineering Design for a 130MW to 210 MW utility-owned facility including capital costs; project financials based on the engineering design and forecasts of energy market revenues; design of the salt cavern to be used for air storage; draft environmental permit filings; and draft NYISO interconnection filing; for Phase 2, objectives included plant construction with a target in-service date of mid-2016; and for Phase 3, objectives included commercial demonstration, testing, and two-years of performance reporting. This Final Report is presented now at the end of Phase 1 because NYSEG has concluded that the economics of the project are not favorable for development in the current economic environment in New York State. The proposed site is located in NYSEG’s service territory in the Town of Reading, New York, at the southern end of Seneca Lake, in New York State’s Finger Lakes region. The landowner of the proposed site is Inergy, a company that owns the salt solution mining facility at this property. Inergy would have developed a new air storage cavern facility to be designed for NYSEG specifically for the Seneca CAES project. A large volume, natural gas storage facility owned and operated by Inergy is also located near this site and would have provided a source of high pressure pipeline quality natural gas for use in the CAES plant. The site has an electrical take-away capability of 210 MW via two NYSEG 115 kV circuits located approximately one half mile from the plant site. Cooling tower make-up water would have been supplied from Seneca Lake. NYSEG’s engineering consultant WorleyParsons Group thoroughly evaluated three CAES designs and concluded that any

  3. Compressed air systems. A guidebook on energy and cost savings

    SciTech Connect

    Not Available

    1984-03-30

    This guidebook shows how energy can be saved in compressed air systems. It discusses basic compressed air systems which are typical of those found in industry and describes them and the engineering practices behind them. Energy conservation recommendations follow. These recommendations cover equipment selection, design, maintenance, and operation. Included is information which will help the reader to make economic evaluations of various engineering and equipment alternatives as they affect operations and costs. The appendices include some modern computer based approaches to predicting pressure drop for designing compressed air distribution systems. Also included is a bibliography providing leads for further and more detailed technical information on these and related subjects.

  4. Analytical and experimental study on complex compressed air pipe network

    NASA Astrophysics Data System (ADS)

    Gai, Yushou; Cai, Maolin; Shi, Yan

    2015-09-01

    To analyze the working characteristics of complex compressed air networks, numerical methods are widely used which are based on finite element technology or intelligent algorithms. However, the effectiveness of the numerical methods is limited. In this paper, to provide a new method to optimize the design and the air supply strategy of the complex compressed air pipe network, firstly, a novel method to analyze the topology structure of the compressed air flow in the pipe network is initially proposed. A matrix is used to describe the topology structure of the compressed air flow. Moreover, based on the analysis of the pressure loss of the pipe network, the relationship between the pressure and the flow of the compressed air is derived, and a prediction method of pressure fluctuation and air flow in a segment in a complex pipe network is proposed. Finally, to inspect the effectiveness of the method, an experiment with a complex network is designed. The pressure and the flow of airflow in the network are measured and studied. The results of the study show that, the predicted results with the proposed method have a good consistency with the experimental results, and that verifies the air flow prediction method of the complex pipe network. This research proposes a new method to analyze the compressed air network and a prediction method of pressure fluctuation and air flow in a segment, which can predicate the fluctuation of the pressure according to the flow of compressed air, and predicate the fluctuation of the flow according to the pressure in a segment of a complex pipe network.

  5. Detail of interior of compressed air chamber showing top of ...

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

    Detail of interior of compressed air chamber showing top of working chamber and tie rods that strengthen the outer shell plates of the compression chamber. - Sub Marine Explorer, Located along the beach of Isla San Telmo, Pearl Islands, Isla San Telmo, Former Panama Canal Zone, CZ

  6. Economic and environmental evaluation of compressed-air cars

    NASA Astrophysics Data System (ADS)

    Creutzig, Felix; Papson, Andrew; Schipper, Lee; Kammen, Daniel M.

    2009-10-01

    Climate change and energy security require a reduction in travel demand, a modal shift, and technological innovation in the transport sector. Through a series of press releases and demonstrations, a car using energy stored in compressed air produced by a compressor has been suggested as an environmentally friendly vehicle of the future. We analyze the thermodynamic efficiency of a compressed-air car powered by a pneumatic engine and consider the merits of compressed air versus chemical storage of potential energy. Even under highly optimistic assumptions the compressed-air car is significantly less efficient than a battery electric vehicle and produces more greenhouse gas emissions than a conventional gas-powered car with a coal intensive power mix. However, a pneumatic-combustion hybrid is technologically feasible, inexpensive and could eventually compete with hybrid electric vehicles.

  7. Compressed air piping, 241-SY-101 hydraulic pump retrieval trailer

    SciTech Connect

    Wilson, T.R.

    1994-12-12

    The following Design Analysis was prepared by the Westinghouse Hanford Company to determine pressure losses in the compressed air piping installed on the hydraulic trailer for the 241-SY-101 pump retrieval mission.

  8. Improving Compressed Air System Performance: A Sourcebook for Industry

    SciTech Connect

    2003-11-01

    NREL will produce this sourcebook for DOE's Industrial Technologies Office as part of a series of documents on industrial energy equipment. The sourcebook is a reference for industrial compressed air system users, outlining opportunities to improve system efficiency.

  9. Acceptance Test Report for 241-U compressed air system

    SciTech Connect

    Freeman, R.D.

    1994-10-20

    This Acceptance Test Report (ATR) documents the results of acceptance testing of a newly upgraded compressed air system at 241-U Farm. The system was installed and the test successfully performed under work package 2W-92-01027.

  10. Investigation on wind energy-compressed air power system.

    PubMed

    Jia, Guang-Zheng; Wang, Xuan-Yin; Wu, Gen-Mao

    2004-03-01

    Wind energy is a pollution free and renewable resource widely distributed over China. Aimed at protecting the environment and enlarging application of wind energy, a new approach to application of wind energy by using compressed air power to some extent instead of electricity put forward. This includes: explaining the working principles and characteristics of the wind energy-compressed air power system; discussing the compatibility of wind energy and compressor capacity; presenting the theoretical model and computational simulation of the system. The obtained compressor capacity vs wind power relationship in certain wind velocity range can be helpful in the designing of the wind power-compressed air system. Results of investigations on the application of high-pressure compressed air for pressure reduction led to conclusion that pressure reduction with expander is better than the throttle regulator in energy saving.

  11. Experience with compressed air cleaning of main steam piping

    SciTech Connect

    Skrgic, P.J. ); Brookins, C. ); Larson, L.; Rothe, D. ); Pier, J.B.; Goldman, G. )

    1990-01-01

    This paper presents a summary of long-term and short-term experience that demonstrates compressed air-blow results are at least as good, and often better than steam-blows. Compressed air-blows have been used effectively on applications for supercritical boilers, drum-type boilers, and heat recovery steam generators for preoperational cleaning of main steam lines at power plants with ratings from 35 to 700 MW.

  12. 46 CFR 112.50-7 - Compressed air starting.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-7 Compressed..., and energy storing devices must be in the emergency generator room, except for the main or auxiliary... emergency generator room and a handcranked, diesel-powered air compressor for recharging the air receiver...

  13. 46 CFR 112.50-7 - Compressed air starting.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-7 Compressed..., and energy storing devices must be in the emergency generator room, except for the main or auxiliary... emergency generator room and a handcranked, diesel-powered air compressor for recharging the air receiver...

  14. 46 CFR 112.50-7 - Compressed air starting.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-7 Compressed..., and energy storing devices must be in the emergency generator room, except for the main or auxiliary... emergency generator room and a handcranked, diesel-powered air compressor for recharging the air receiver...

  15. 46 CFR 112.50-7 - Compressed air starting.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... AND POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-7 Compressed..., and energy storing devices must be in the emergency generator room, except for the main or auxiliary... emergency generator room and a handcranked, diesel-powered air compressor for recharging the air receiver...

  16. Summary of selected compressed air energy storage studies

    SciTech Connect

    Allen, R.D.; Doherty, T.J.; Kannberg, L.D.

    1985-01-01

    A descriptive summarily of research and development in compressed air energy storage technology is presented. Research funded primarily by the Department of Energy is described. Results of studies by other groups and experience at the Huntorf plant in West Germany are included. Feasibility studies performed by General Electric are summarized. The feasibility of air storage in dissolved salt cavities is also demonstrated. (BCS)

  17. Exergy analysis of vapor compression refrigeration cycle with two-stage and intercooler

    NASA Astrophysics Data System (ADS)

    Kılıç, Bayram

    2012-07-01

    In this study, exergy analyses of vapor compression refrigeration cycle with two-stage and intercooler using refrigerants R507, R407c, R404a were carried out. The necessary thermodynamic values for analyses were calculated by Solkane program. The coefficient of performance, exergetic efficiency and total irreversibility rate of the system in the different operating conditions for these refrigerants were investigated. The coefficient of performance, exergetic efficiency and total irreversibility rate for alternative refrigerants were compared.

  18. Air ejector augmented compressed air energy storage system

    DOEpatents

    Ahrens, Frederick W.; Kartsounes, George T.

    1980-01-01

    Energy is stored in slack demand periods by charging a plurality of underground reservoirs with air to the same peak storage pressure, during peak demand periods throttling the air from one storage reservoir into a gas turbine system at a constant inlet pressure until the air pressure in the reservoir falls to said constant inlet pressure, thereupon permitting air in a second reservoir to flow into said gas turbine system while drawing air from the first reservoir through a variable geometry air ejector and adjusting said variable geometry air ejector, said air flow being essentially at the constant inlet pressure of the gas turbine system.

  19. Air ejector augmented compressed air energy storage system

    DOEpatents

    Ahrens, F.W.; Kartsounes, G.T.

    Energy is stored in slack demand periods by charging a plurality of underground reservoirs with air to the same peak storage pressure, during peak demand periods throttling the air from one storage reservoir into a gas turbine system at a constant inlet pressure until the air presure in the reservoir falls to said constant inlet pressure, thereupon permitting air in a second reservoir to flow into said gas turbine system while drawing air from the first reservoir through a variable geometry air ejector and adjusting said variable geometry air ejector, said air flow being essentially at the constant inlet pressure of the gas turbine system.

  20. Consistent air quality and energy savings provided by heat of compression air dryer

    SciTech Connect

    Brown, F.; Hodel, A.E.

    1986-02-01

    The six-year-old compressed air dryers serving the plant and instrument air needs at Monsanto Company's W.G. Krummrich plant in Sauget, IL were no longer performing at peak efficiency. Dryer reliability had declined. Energy usage of the heat regenerated dryers was substantial. The 60 kw heaters used to regenerate the desiccant were operating 2 1/2 out of 4 hours on a timer controlled continuous cycle. Engineers decided to remove the old, inefficient air compression and drying equipment air compression and drying equipment at the W.G. Krummrich plant and replace it with a state-of-the-art system. The combination of a compressor and dryer package was specified to incorporate heat recovery/energy savings. Monsanto's engineers specified an air system that would operate on demand and use a heat of compression air dryer that was available commercially.

  1. Prefeasibility study on compressed air energy storage systems

    NASA Astrophysics Data System (ADS)

    Elmahgary, Yehia; Peltola, Esa; Sipila, Kari; Vaatainen, Anne

    1991-08-01

    A prefeasibility study on Compressed Air Energy Storage (CAES) systems is presented. The costs of excavating rock caverns for compressed air storage and those for forming suitable storage caverns in existing mines were estimated, and this information was used to calculate the economics of CAES. An analysis of the different possible systems is given following a review of literature on CAES. This was followed by an economic analysis which comprised two separate systems. The first consisted of conventional oil fueled gas turbine plants provided with CAES system. In the second system wind turbines were used to run the compressors which are used in charging the compressed air storage cavern. The results of the current prefeasibility study confirmed the economic attractiveness of the CAES in the first system. Wind turbines still seem, however, to be too expensive to compete with coal power plants. More accurate and straightforward results could be obtained only in a more comprehensive study.

  2. Compressed Air System Optimization: Case Study Food Industry in Indonesia

    NASA Astrophysics Data System (ADS)

    Widayati, Endang; Nuzahar, Hasril

    2016-01-01

    Compressors and compressed air systems was one of the most important utilities in industries or factories. Approximately 10% of the cost of electricity in the industry was used to produce compressed air. Therefore the potential for energy savings in the compressors and compressed air systems had a big challenge. This field was conducted especially in Indonesia food industry or factory. Compressed air system optimization was a technique approach to determine the optimal conditions for the operation of compressors and compressed air systems that included evaluation of the energy needs, supply adjustment, eliminating or reconfiguring the use and operation of inefficient, changing and complementing some equipment and improving operating efficiencies. This technique gave the significant impact for energy saving and costs. The potential savings based on this study through measurement and optimization e.g. system that lowers the pressure of 7.5 barg to 6.8 barg would reduce energy consumption and running costs approximately 4.2%, switch off the compressor GA110 and GA75 was obtained annual savings of USD 52,947 ≈ 455 714 kWh, running GA75 light load or unloaded then obtained annual savings of USD 31,841≈ 270,685 kWh, install new compressor 2x132 kW and 1x 132 kW VSD obtained annual savings of USD 108,325≈ 928,500 kWh. Furthermore it was needed to conduct study of technical aspect of energy saving potential (Investment Grade Audit) and performed Cost Benefit Analysis. This study was one of best practice solutions how to save energy and improve energy performance in compressors and compressed air system.

  3. 29 CFR 1926.803 - Compressed air.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... that an air space is created when the seat lid is closed. (v) Fresh and pure drinking water shall be... providing drinking fountains, or by providing individual canteens, or by some other sanitary means. Community drinking vessels are prohibited. (vi) No refuse or discarded material of any kind shall be...

  4. 29 CFR 1926.803 - Compressed air.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... that an air space is created when the seat lid is closed. (v) Fresh and pure drinking water shall be... providing drinking fountains, or by providing individual canteens, or by some other sanitary means. Community drinking vessels are prohibited. (vi) No refuse or discarded material of any kind shall be...

  5. 29 CFR 1926.803 - Compressed air.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... that an air space is created when the seat lid is closed. (v) Fresh and pure drinking water shall be... providing drinking fountains, or by providing individual canteens, or by some other sanitary means. Community drinking vessels are prohibited. (vi) No refuse or discarded material of any kind shall be...

  6. 29 CFR 1926.803 - Compressed air.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... that an air space is created when the seat lid is closed. (v) Fresh and pure drinking water shall be... providing drinking fountains, or by providing individual canteens, or by some other sanitary means. Community drinking vessels are prohibited. (vi) No refuse or discarded material of any kind shall be...

  7. 29 CFR 1926.803 - Compressed air.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... that an air space is created when the seat lid is closed. (v) Fresh and pure drinking water shall be... providing drinking fountains, or by providing individual canteens, or by some other sanitary means. Community drinking vessels are prohibited. (vi) No refuse or discarded material of any kind shall be...

  8. Air Compressibility Effect on Bouwer and Rice Seepage Meter.

    PubMed

    Peng, Xin; Zhan, Hongbin

    2017-07-17

    Measuring a disconnected streambed seepage flux using a seepage meter can give important streambed information and help understanding groundwater-surface water interaction. In this study, we provide a correction for calculating the seepage flux rate with the consideration of air compressibility inside the manometer of the Bouwer and Rice seepage meter. We notice that the effect of air compressibility in the manometer is considerably larger when more air is included in the manometer. We find that the relative error from neglecting air compressibility can be constrained within 5% if the manometer of the Bouwer and Rice seepage meter is shorter than 0.8 m and the experiment is done in a suction mode in which air is pumped out from the manometer before the start of measurement. For manometers longer than 0.8 m, the relative error will be larger than 5%. It may be over 10% if the manometer height is longer than 1.5 m and the experiment is done in a no-suction mode, in which air is not pumped out from the manometer before the start of measurement. © 2017, National Ground Water Association.

  9. Legal and regulatory issues affecting compressed air energy storage

    SciTech Connect

    Hendrickson, P.L.

    1981-07-01

    Several regulatory and legal issues that can potentially affect implementation of a compressed air energy storage (CAES) system are discussed. This technology involves the compression of air using base load electric power for storage in an underground storage medium. The air is subsequently released and allowed to pass through a turbine to generate electricity during periods of peak demand. The storage media considered most feasible are a mined hard rock cavern, a solution-mined cavern in a salt deposit, and a porous geologic formation (normally an aquifer) of suitable structure. The issues are discussed in four categories: regulatory issues common to most CAES facilities regardless of storage medium, regulatory issues applicable to particular CAES reservoir media, issues related to possible liability from CAES operations, and issues related to acquisition of appropriate property rights for CAES implementation. The focus is on selected federal regulation. Lesser attention is given to state and local regulation. (WHK)

  10. Compressed Air System Retrofit Reduces Energy Costs at a Newspaper Printing Facility

    SciTech Connect

    2002-05-01

    In 2000, a compressed air system optimization project was implemented at The Bakersfield Californian's printing facility in Bakersfield, California. The compressed air system was evaluated for potential energy efficiency improvement opportunities in response to rising energy costs.

  11. Compressed Air System Optimization Improves Production and saves energy at a Satellite Manufacturer

    SciTech Connect

    2002-05-01

    In 2001, a compressed air improvement project was implemented following an audit on the compressed air system at Boeing Satellite Systems (formerly Hughes Space & Communications Company) in Los Angeles, California.

  12. Compressed-air power tools in orthopaedic surgery: exhaust air is a potential source of contamination.

    PubMed

    Sagi, H C; DiPasquale, Thomas; Sanders, Roy; Herscovici, Dolfi

    2002-01-01

    To determine if the exhaust from surgical compressed-air power tools contains bacteria and if the exhaust leads to contamination of sterile surfaces. Bacteriologic study of orthopaedic power tools. Level I trauma center operative theater. None. Part I. Exhaust from two sterile compact air drills was sampled directly at the exhaust port. Part II. Exhaust from the drills was directed at sterile agar plates from varying distances. The agar plates represented sterile surfaces within the operative field. Part III. Control cultures. A battery-powered drill was operated over open agar plates in similar fashion as the compressed-air drills. Agar plates left open in the operative theater served as controls to rule out atmospheric contamination. Random cultures were taken from agar plates, gloves, drills, and hoses. Incidence of positive cultures. In Part I, all filters from both compressed-air drill exhausts were culture negative ( = 0.008). In Part II, the incidence of positive cultures for air drills number one and number two was 73% and 82%, respectively. The most commonly encountered organisms were, coagulase-negative Staphylococcus, and Micrococcus species. All control cultures from agar plates, battery-powered drill, gloves, and hoses were negative ( < 0.01). Exhaust from compressed-air power tools in orthopaedic surgery may contribute to the dissemination of bacteria onto the surgical field. We do not recommend the use of compressed-air power tools that do not have a contained exhaust.

  13. Environmental and regulatory aspects of compressed-air energy storage

    SciTech Connect

    Beckwith, M.A.; Mathur, J.

    1981-01-01

    The effects of fuel regulations, environmental protection laws, the National Environmental Policy Act, underground injection regulations, and state regulations on the development of compressed air storage systems and power plants are discussed. It is concluded that environmental regulatory concerns of conventional energy technologies are often different from those associated with new technologies such as compressed air energy storage (CAES). Confusion and uncertainty often results when the current environmental regulatory system is applied to new technologies. Evolution of the regulatory system must accompany and rapidly accommodate technological development if the benefits of such development are to be fully realized in a timely manner. Those responsible for technological development in the energy field must be aware of these disparities and conduct their efforts accordingly.

  14. CLASSIFICATION OF THE MGR SITE COMPRESSED AIR SYSTEM

    SciTech Connect

    J.A. Ziegler

    1999-08-31

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) site compressed air system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998).

  15. Orbital compressed air and petroleum injury mimicking necrotizing fasciitis.

    PubMed

    Mellington, Faye E; Bacon, Annette S; Abu-Bakra, Mohammed A J; Martinez-Devesa, Pablo; Norris, Jonathan H

    2014-09-01

    Orbital injury secondary to petroleum-based products is rare. We report the first case, to our knowledge, of a combined compressed air and chemical orbital injury, which mimicked necrotizing fasciitis. A 58-year-old man was repairing his motorcycle engine when a piston inadvertently fired, discharging compressed air and petroleum-based carburetor cleaner into his left eye. He developed surgical emphysema, skin necrosis, and a chemical cellulitis, causing an orbital compartment syndrome. He was treated initially with antibiotics and subsequently with intravenous steroid and orbital decompression surgery. There was almost complete recovery by 4 weeks postsurgery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Petroleum-based products can cause severe skin irritation and necrosis. Compressed air injury can cause surgical emphysema. When these two mechanisms of injury are combined, the resulting orbitopathy and skin necrosis can mimic necrotizing fasciitis and cause diagnostic confusion. A favorable outcome is achievable with aggressive timely management. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Prefeasibility study on compressed air energy storage systems

    NASA Astrophysics Data System (ADS)

    Elmahgary, Y.; Peltola, E.; Sipilae, K.; Vaeaetaeinen, A.

    1991-08-01

    A prefeasibility study on compressed air energy storage (CALS) systems was launched in VTT in the course of the year 1990. The study was undertaken partly in the Laboratory of Electrical and Automation Engineering and partly in the Road, Traffic and Geotechnical Laboratory. Information on existing mines in Finland which could be used as storage caverns were collected (part 2). The costs of excavating rock caverns for compressed air storage and those for forming suitable storage caverns in existing mines were also estimated. This information was used in the first (and present) part of the report to calculate the economics of CAES. In the present part (part 1) of the study, an analysis of the different possible systems was given following a review of literature on CAES. This was followed by an economic analysis which comprised two separate systems. The first consisted of conventional oil fueled gas turbine plants provided with the CALS system. In the second system, wind turbines were used to run the compressors which are used in charging the compressed air storage cavern. The results of the current prefeasibility study confirmed the economic attractiveness of the CAES in the first system. Wind turbines still seem, however, to be too expensive to compete with coal power plants. More accurate and straight-forward results could be obtained only in a more comprehensive study.

  17. Automatic device for indirect measurement of leakage flow rate in compressed air pipeline

    NASA Astrophysics Data System (ADS)

    Dindorf, R.; Wos, P.; Pawelec, K.

    2017-08-01

    The new measurement method of compressed air leakage flow rate in compressed air pipeline is proposed. In this method, the automatic measuring device is connected to a branch of the pipeline. The measuring device can be used to measure compressed air leakage in any place of compressed air pipeline: in main line, distribution line and connection line. The proposed measurement methods of compressed air leakage in pipeline are independent of receiver and compressor parameters, which is not the case with traditional method measuring leaks by emptying the receiver.

  18. Improved fireman's compressed air breathing system pressure vessel development program

    NASA Technical Reports Server (NTRS)

    King, H. A.; Morris, E. E.

    1973-01-01

    Prototype high pressure glass filament-wound, aluminum-lined pressurant vessels suitable for use in a fireman's compressed air breathing system were designed, fabricated, and acceptance tested in order to demonstrate the feasibility of producing such high performance, lightweight units. The 4000 psi tanks have a 60 standard cubic foot (SCF) air capacity, and have a 6.5 inch diamter, 19 inch length, 415 inch volume, weigh 13 pounds when empty, and contain 33 percent more air than the current 45 SCF (2250 psi) steel units. The current steel 60 SCF (3000 psi) tanks weigh approximately twice as much as the prototype when empty, and are 2 inches, or 10 percent shorter. The prototype units also have non-rusting aluminum interiors, which removes the hazard of corrosion, the need for internal coatings, and the possibility of rust particles clogging the breathing system.

  19. Compressed air energy storage technology program. Annual report for 1980

    SciTech Connect

    Kannberg, L.D.

    1981-06-01

    All of the major research funded under the Compressed Air Energy Storage Technology Program during the period March 1980 to March 1981 is described. This annual report is divided into two segments: Reservoir Stability Studies and Second-Generation Concepts Studies. The first represents research performed to establish stability criteria for CAES reservoirs while the second reports progress on research performed on second-generation CAES concepts. The report consists of project reports authored by research engineers and scientists from PNL and numerous subcontractors including universities, architect-engineering, and other private firms.

  20. Compressed-air energy-storage technology: Program overview

    NASA Astrophysics Data System (ADS)

    Kannberg, L. D.

    1981-07-01

    A new technology designed to reduce the consumption of oil in the generation of electric power was developed. The program has two major elements: reservoir stability studies and second generation concepts studies. The reservoir stability studies are aimed at developing stability criteria for long term operation of large underground reservoirs used for compressed air storage. The second generation concepts studies are aimed at developing new concepts that will require little or no petroleum fuels for operation. The program efforts are outlined and major accomplishments towards the objectives of the program are identified.

  1. Lehigh Southwest Cement Company: Compressed Air System Improvement Saves Energy

    SciTech Connect

    2003-10-01

    In 2001, Lehigh Southwest Cement Company improved the compressed air system at its cement plant in Tehachapi, California. Consequently, the system was able to operate more efficiently with less compressor capacity and at a lower system pressure. The project yielded total annual savings of 895,000 kWh and $199,000. The initial project cost was $417,000, but Southern California Edison provided a $90,000 incentive payment to reduce the cost to $327,000. Simple payback was about 20 months.

  2. Computer aided optimal design of compressed air energy storage systems

    NASA Astrophysics Data System (ADS)

    Ahrens, F. W.; Sharma, A.; Ragsdell, K. M.

    1980-07-01

    An automated procedure for the design of Compressed Air Energy Storage (CAES) systems is presented. The procedure relies upon modern nonlinear programming algorithms, decomposition theory, and numerical models of the various system components. Two modern optimization methods are employed; BIAS, a Method of Multipliers code and OPT, a Generalized Reduced Gradient code. The procedure is demonstrated by the design of a CAES facility employing the Media, Illinois Galesville aquifer as the reservoir. The methods employed produced significant reduction in capital and operating cost, and in number of aquifer wells required.

  3. Geothermally Coupled Well-Based Compressed Air Energy Storage

    SciTech Connect

    Davidson, C L; Bearden, Mark D; Horner, Jacob A; Appriou, Delphine; McGrail, B Peter

    2015-12-01

    Previous work by McGrail et al. (2013, 2015) has evaluated the possibility of pairing compressed air energy storage with geothermal resources in lieu of a fossil-fired power generation component, and suggests that such applications may be cost competitive where geology is favorable to siting both the geothermal and CAES components of such a system. Those studies also note that the collocation of subsurface resources that meet both sets of requirements are difficult to find in areas that also offer infrastructure and near- to mid-term market demand for energy storage. This study examines a novel application for the compressed air storage portion of the project by evaluating the potential to store compressed air in disused wells by amending well casings to serve as subsurface pressure vessels. Because the wells themselves would function in lieu of a geologic storage reservoir for the CAES element of the project, siting could focus on locations with suitable geothermal resources, as long as there was also existing wellfield infrastructure that could be repurposed for air storage. Existing wellfields abound in the United States, and with current low energy prices, many recently productive fields are now shut in. Should energy prices remain stagnant, these idle fields will be prime candidates for decommissioning unless they can be transitioned to other uses, such as redevelopment for energy storage. In addition to the nation’s ubiquitous oil and gas fields, geothermal fields, because of their phased production lifetimes, also may offer many abandoned wellbores that could be used for other purposes, often near currently productive geothermal resources. These existing fields offer an opportunity to decrease exploration and development uncertainty by leveraging data developed during prior field characterization, drilling, and production. They may also offer lower-cost deployment options for hybrid geothermal systems via redevelopment of existing well-field infrastructure

  4. Geothermally Coupled Well-Based Compressed Air Energy Storage

    SciTech Connect

    Davidson, Casie L.; Bearden, Mark D.; Horner, Jacob A.; Cabe, James E.; Appriou, Delphine; McGrail, B. Peter

    2015-12-20

    Previous work by McGrail et al. (2013, 2015) has evaluated the possibility of pairing compressed air energy storage with geothermal resources in lieu of a fossil-fired power generation component, and suggests that such applications may be cost competitive where geology is favorable to siting both the geothermal and CAES components of such a system. Those studies also note that the collocation of subsurface resources that meet both sets of requirements are difficult to find in areas that also offer infrastructure and near- to mid-term market demand for energy storage. This study examines a novel application for the compressed air storage portion of the project by evaluating the potential to store compressed air in disused wells by amending well casings to serve as subsurface pressure vessels. Because the wells themselves would function in lieu of a geologic storage reservoir for the CAES element of the project, siting could focus on locations with suitable geothermal resources, as long as there was also existing wellfield infrastructure that could be repurposed for air storage. Existing wellfields abound in the United States, and with current low energy prices, many recently productive fields are now shut in. Should energy prices remain stagnant, these idle fields will be prime candidates for decommissioning unless they can be transitioned to other uses, such as redevelopment for energy storage. In addition to the nation’s ubiquitous oil and gas fields, geothermal fields, because of their phased production lifetimes, also may offer many abandoned wellbores that could be used for other purposes, often near currently productive geothermal resources. These existing fields offer an opportunity to decrease exploration and development uncertainty by leveraging data developed during prior field characterization, drilling, and production. They may also offer lower-cost deployment options for hybrid geothermal systems via redevelopment of existing well-field infrastructure

  5. Compressed air energy storage technology program. Annual report for 1979

    SciTech Connect

    Loscutoff, W.V.

    1980-06-01

    The objectives of the Compressed Air Energy Storage (CAES) program are to establish stability criteria for large underground reservoirs in salt domes, hard rock, and porous rock used for air storage in utility applications, and to develop second-generation CAES technologies that have minimal or no dependence on petroleum fuels. During the year reported reports have been issued on field studies on CAES on aquifers and in salt, stability, and design criteria for CAES and for pumped hydro-storage caverns, laboratory studies of CAES in porous rock reservoris have continued. Research has continued on combined CAES/Thermal Energy Storage, CAES/Solar systems, coal-fired fluidized bed combustors for CAES, and two-reservoir advanced CAES concepts. (LCL)

  6. Carbon and energy saving markets in compressed air

    NASA Astrophysics Data System (ADS)

    Cipollone, R.

    2015-08-01

    CO2 reduction and fossil fuel saving represent two of the cornerstones of the environmental commitments of all the countries of the world. The first engagement is of a medium to long term type, and unequivocally calls for a new energetic era. The second delays in time the fossil fuel technologies to favour an energetic transition. In order to sustain the two efforts, new immaterial markets have been established in almost all the countries of the world, whose exchanges (purchases and sales) concern CO2 emissions and equivalent fossil fuels that have not been emitted or burned. This paper goes deep inside two aspects not yet exploited: specific CO2 emissions and equivalent fossil fuel burned, as a function of compressed air produced. Reference is made to the current compressor technology, carefully analysing CAGI's (Compressed Air Gas Institute) data and integrating it with the PNUEROP (European Association of manufacturers of compressors, vacuum pumps, pneumatic tools and allied equipment) contribution on the compressor European market. On the base of energy saving estimates that could be put in place, this article also estimates the financial value of the CO2 emissions and fossil fuels avoided.

  7. Evaluation of the Compressed Air Challenge(R) Training Program (Executive Summary)

    SciTech Connect

    Not Available

    2004-03-01

    The final report of the evaluation of the Compressed Air Challenge (CAC) Training Program. The training program is designed to provide plant personnel and compressed air system vendors with knowledge and tools required to effect improvements to the energy efficiency and overall performance of plant compressed air systems. As of May 2001, 3,029 individuals had attended the CAC Fundamentals of Compressed Air Training Systems and 925 individuals had attended ''Advanced Management of Compressed Air Systems''. These individuals represented 1,400-1,500 separate business establishments. The evaluation is based on three main research tasks: analysis of the CAC registration database, interviews with 100 end-user personnel who attended the CAC training, and interviews with 100 compressed air system vendors and consulting engineers who attended the training sessions.

  8. Improving Compressed Air System Performance: A Sourcebook for Industry v3

    SciTech Connect

    Ron Marshall, William Scales, Gary Shafer, Paul Shaw, Paul Sheaffer, Rick Stasyshan, H.P.

    2016-03-01

    This sourcebook is designed to provide compressed air system users with a reference that outlines opportunities for system performance improvements. It is not intended to be a comprehensive technical text on improving compressed air systems, but rather a document that makes compressed air system users aware of the performance improvement potential, details some of the significant opportunities, and directs users to additional sources of assistance.

  9. Compressed breathing air - the potential for evil from within.

    PubMed

    Millar, Ian L; Mouldey, Peter G

    2008-06-01

    Human underwater activities rely on an adequate supply of breathable compressed gas, usually air, free from contaminants that could cause incapacitation underwater or post-dive or longer-term health effects. Potentially fatal but well-known hazards are hypoxia secondary to steel cylinder corrosion and carbon monoxide (CO) poisoning due to contaminated intake air. Another phenomenon may be behind some previously unexplained episodes of underwater incapacitation and perhaps death: low-level CO poisoning and/or the effects of gaseous contaminants generated within the compressor, including toluene and other volatile compounds. Many low molecular weight volatile contaminants are anaesthetic and will be potentiated by pressure and nitrogen narcosis. In sub-anaesthetic doses, impaired judgement, lowered seizure threshold and sensitisation of the heart to arrhythmias may occur. Toxic compounds can be volatilised from some compressor oils, especially mineral oils, in overheated compressors, or be created de novo under certain combinations of temperature, humidity and pressure, perhaps catalysed by metal traces from compressor wear and tear. Most volatiles can be removed by activated carbon filtration but many filters are undersized and may overload in hot, moist conditions and with short dwell times. A compressor that passes normal testing could contaminate one or more cylinders after heating up and then return to producing clean air as the filters dry and the systems cool. The scope of this problem is very unclear as air quality is tested infrequently and often inadequately, even after fatalities. More research is needed as well as better education regarding the safe operation and limitations of high-pressure breathing air compressors.

  10. Compressed-air energy storage: Pittsfield aquifer field test

    SciTech Connect

    Bui, H.V.; Herzog, R.A.; Jacewicz, D.M.; Lange, G.R.; Scarpace, E.R.; Thomas, H.H. )

    1990-02-01

    This report documents the results of a comprehensive investigation into the practical feasibility for Compressed Air Energy Storage (CAES) in Porous Media. Natural gas porous media storage technology developed from seventy years of experience by the natural gas storage industry is applied to the investigation of CAES in porous media. A major objective of this investigation is the geologic characterization, deliverability prediction, and operations analysis of the Pittsfield CAES aquifer experiment, conducted in Pike County, Illinois during 1981--85 under EPRI/DOE sponsorship. Emphasis has been placed on applying accepted petroleum engineering concepts to the study of deliverability and on the characterization and quantification of oxygen losses which reportedly occurred at Pittsfield. Other objectives are to apply the natural gas underground storage technology and approach to a general study of CAES feasibility in porous media reservoirs, with emphasis on the practical risks and constraints of air storage in aquifer and depleted natural gas reservoirs, the effects of water on CAES operation, corrosion effects, and a review of air dehydration options.

  11. Recent Research in Compression Refrigeration Cycle Air Source Heat Pumps.

    NASA Astrophysics Data System (ADS)

    Arai, Akira; Senshu, Takao

    The most important theme for heat pump air conditioners is the improvement of energy saving and comfort. Recently, cycle components, especially compressores and heat exchangers have been improved greatly in their performance and efficiency. As for compressors, large progress in their efficiencies have been made by detailed analysises such as mechanical losses and by the development of a new type compression mechanism. As for heat exchangers, various high heat transfer surfaces have been developed together with the improvement of the production technologies for them. Further, the effect of the capacity-modulated cycle is evaluated quantitatively through the improvements of static and transient cycle simulation technologies. And in order to realize this cffect, the electrically driven expansion valves heve been marketed. This review introduces the trends of these energy-saving technologies as well as comfort improvement studies.

  12. Interaction of air shock waves and porous compressible materials

    NASA Astrophysics Data System (ADS)

    Gvozdeva, L. G.; Faresov, Yu. M.; Fokeyev, V. P.

    1986-05-01

    Interaction of air shock waves and porous compressible materials was studied in an experiment with two foam-plastic materials: PPU-3M-1 polyurethane (density 33 kg/cu m) and much more rigid PKhV-1 polyvinyl chloride (density 50 kg/cu m). Tests were performed in a shock tube with 0.1x0.1 m square cross-section, a single diaphragm separating its 8 m long low-pressure segment with inspection zone and 1.5 m long high-pressure segment. The instrumentation included an array of piezoelectric pressure transducers and a digital frequency meter for velocity measurements, a Tectronix 451A oscillograph, and IAB-451 shadowgraph, and a ZhFR camera with slit scanning. Air was used as compressing gas, its initial pressure being varied from 10(3) Pa to 10(5) Pa, helium and nitrogen were used as propelling gas. The impact velocity of shock waves was varied over the N(M) = 2-5 range of the Mach number. The maximum amplitude of the pressure pulse increased as the thickness of the foam layer was increased up to 80 mm and then remained constant with further increases of that thickness, at a level depending on the material and on the intitial conditions. A maximum pressure rise by a factor of approximately 10 was attained, with 1.3 x 10(3) Pa initial pressure and an impact velocity N(M) = 5. Reducing the initial pressure to below (0.1-0.3) x 10(3) Pa, with the impact velocity maintained at N(M) = 5, reduced the pressure rise to a factor below 3. The results are interpreted taking into account elasticity forces in the solid skeleton phase and gas filtration through the pores.

  13. 29 CFR 1926.913 - Blasting in excavation work under compressed air.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Blasting in excavation work under compressed air. 1926.913... ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Blasting and the Use of Explosives § 1926.913 Blasting in excavation work under compressed air. (a) Detonators and...

  14. 30 CFR 56.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure vessels... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Inspection of compressed-air receivers and other unfired pressure vessels. 56.13015 Section 56.13015 Mineral Resources MINE SAFETY AND HEALTH...

  15. 30 CFR 57.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... receivers and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Inspection of compressed-air receivers and other unfired pressure vessels. 57.13015 Section 57.13015 Mineral Resources MINE SAFETY AND HEALTH...

  16. 30 CFR 56.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure vessels... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Inspection of compressed-air receivers and other unfired pressure vessels. 56.13015 Section 56.13015 Mineral Resources MINE SAFETY AND HEALTH...

  17. 30 CFR 57.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... receivers and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Inspection of compressed-air receivers and other unfired pressure vessels. 57.13015 Section 57.13015 Mineral Resources MINE SAFETY AND HEALTH...

  18. 30 CFR 57.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... receivers and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Inspection of compressed-air receivers and other unfired pressure vessels. 57.13015 Section 57.13015 Mineral Resources MINE SAFETY AND HEALTH...

  19. 30 CFR 56.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure vessels... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Inspection of compressed-air receivers and other unfired pressure vessels. 56.13015 Section 56.13015 Mineral Resources MINE SAFETY AND HEALTH...

  20. 30 CFR 56.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure vessels... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Inspection of compressed-air receivers and other unfired pressure vessels. 56.13015 Section 56.13015 Mineral Resources MINE SAFETY AND HEALTH...

  1. 30 CFR 57.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... receivers and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Inspection of compressed-air receivers and other unfired pressure vessels. 57.13015 Section 57.13015 Mineral Resources MINE SAFETY AND HEALTH...

  2. 30 CFR 56.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure vessels... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Inspection of compressed-air receivers and other unfired pressure vessels. 56.13015 Section 56.13015 Mineral Resources MINE SAFETY AND HEALTH...

  3. 30 CFR 57.13015 - Inspection of compressed-air receivers and other unfired pressure vessels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... receivers and other unfired pressure vessels. (a) Compressed-air receivers and other unfired pressure... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Inspection of compressed-air receivers and other unfired pressure vessels. 57.13015 Section 57.13015 Mineral Resources MINE SAFETY AND HEALTH...

  4. Spark-ignition, air-compressing, internal combustion engine

    SciTech Connect

    Chmela, F.; Herzog, W.; Meier, R.

    1988-09-20

    This patent describes a spark-ignition, air-compressing, internal combustion engine that has direct ignition of a major portion of the fuel by means of a jet onto the wall of the combustion chamber that is provided, in the shape of a body of revolution, in the piston, whereby rotary motion is imparted by means known per se to the inflowing air in the direction of the injected fuel jet so as to cause the fuel to be removed gradually in the vapor state from the wall of the combustion chamber and to be mixed with the air, the injection nozzle being located in the cylinder head near the combustion chamber rim, with the spark plug, which is disposed opposite the injection nozzle, extending into the combustion chamber in the top dead center position of the piston, with the side wall of the combustion chamber, when viewed in cross section, being formed by two arcs that blend into each other and have respective radii of curvature R/sub 1/, R/sub 2/, the first arc having a radius R/sub 1/ that extends from a restricted combustion chamber opening down to the maximum combustion chamber diameter D/sub B/, and the second arc having a radius R/sub 2/ that extends down to the bottom of the combustion chamber and blends into the latter. The maximum combustion chamber diameter D/sub B/ being 0.5 to 0.7 times the diameter D/sub K/ of the piston and being at a defined depth t/sub D/ from the piston crown relative to the depth T/sub B/ of the combustion chamber, the ratio of the diameter d/sub H/ of the combustion chamber opening to the maximum combustion chamber diameter D/sub B/.

  5. The research of press drop of compressed air foam flow through the bend

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Chen, T.; Hu, C.; Fu, X. C.; Bao, Z. M.; Zhang, X. Z.; Xia, J. J.

    2017-08-01

    Compressed air foam system (CAFS) had obvious advantages in engineering. The flow model of compressed air foam in the pipeline was different from water flow model because the foam was the gas-liquid two phase flow with non-Newtonian fluid properties and compressibility, and, the water supply theory was not suitable for foam press pipeline transport. At present, there was little research on non-Newtonian fluid flow, especially the foam flow. This study researched the effect of foam flux, end valve and foam type on the press in the straight pipe and bend. The press drop in straight pipes and bends filled with compressed air foam was analyzed, and the result could provide experimental support for theoretical calculation of compressed air foam in bend.

  6. Integration of Wind Turbines with Compressed Air Energy Storage

    NASA Astrophysics Data System (ADS)

    Arsie, I.; Marano, V.; Rizzo, G.; Moran, M.

    2009-08-01

    Some of the major limitations of renewable energy sources are represented by their low power density and intermittent nature, largely depending upon local site and unpredictable weather conditions. These problems concur to increase the unit costs of wind power, so limiting their diffusion. By coupling storage systems with a wind farm, some of the major limitations of wind power, such as a low power density and an unpredictable nature, can be overcome. After an overview on storage systems, the Compressed Air Energy Storage (CAES) is analyzed, and the state of art on such systems is discussed. A Matlab/Simulink model of a hybrid power plant consisting of a wind farm coupled with CAES is then presented. The model has been successfully validated starting from the operating data of the McIntosh CAES Plant in Alabama. Time-series neural network-based wind speed forecasting are employed to determine the optimal daily operation strategy for the storage system. A detailed economic analysis has been carried out: investment and maintenance costs are estimated based on literature data, while operational costs and revenues are calculated according to energy market prices. As shown in the paper, the knowledge of the expected available energy is a key factor to optimize the management strategies of the proposed hybrid power plant, allowing to obtain environmental and economic benefits.

  7. Assessment of market potential of compressed air energy storage systems

    NASA Astrophysics Data System (ADS)

    Boyd, D. W.; Buckley, O. E.; Clark, C. E., Jr.

    1983-12-01

    This report describes an assessment of potential roles that EPRI might take to facilitate the commercial acceptance of compressed air energy storage (CAES) systems. The assessment is based on (1) detailed analyses of the market potential of utility storage technologies, (2) interviews with representatives of key participants in the CAES market, and (3) a decision analysis synthesizing much of the information about market and technology status. The results indicate a large potential market for CAES systems if the overall business environment for utilities improves. In addition, it appears that EPRI can have a valuable incremental impact in ensuring that utilities realize the potential of CAES by (1) continuing an aggressive information dissemination and technology transfer program, (2) working to ensure the success of the first United States CAES installation at Soyland Power Cooperative, (3) developing planning methods to allow utilities to evaluate CAES and other storage options more effectively and more realistically, and (4) supporting R and D to resolve residual uncertainties in first-generation CAES cost and performance characteristics. Previously announced in STAR as N83-25121

  8. Internal combustion engine with compressed air collection system

    SciTech Connect

    Brown, P.W.

    1988-08-23

    This patent describes an internal combustion engine comprising cylinders respectively including a pressure port, pistons respectively movable in the cylinders through respective compression strokes, fuel injectors respectively connected to the cylinders and operative to supply, from a fuel source to the respective cylinders, a metered quantity of fuel conveyed by compressed gas in response to fuel injector operation during the compression strokes of the respective cylinders, a storage tank for accumulating and storing compressed gas, means for selectively connecting the pressure ports to the storage tank only during the compression strokes of the respective cylinders, and duct means connecting the storage tank to the fuel injectors for supplying the fuel injectors with compressed gas in response to fuel injector operation.

  9. Upgrade of Compressed Air Control System Reduces Energy Costs at Michelin Tire Plant

    SciTech Connect

    2002-01-01

    This case study highlights the upgraded compressed air system at a Michelin tire manufacturing plant in Spartanburg, South Carolina. The controls upgrade project enabled multiple compressor operation without blow-off, and significantly reduced energy costs.

  10. Effects of boundary layer and liquid viscosity and compressible air on sloshing characteristics

    NASA Astrophysics Data System (ADS)

    Zou, Chang-Fang; Wang, De-Yu; Cai, Zhong-Hua

    2015-07-01

    In this paper, numerical investigations for tank sloshing, based on commercial CFD package FLUENT, are performed to study effects of boundary layer grid, liquid viscosity and compressible air on sloshing pressure, wave height and rising time of impact pressure. Also, sloshing experiments for liquids of different viscosity are carried out to validate the numerical results. Through comparison of numerical and experimental results, a computational model including boundary layer grid can predict the sloshing pressure more accurately. Energy dissipation due to viscous friction leads to reduction of sloshing pressure and wave elevation. Sloshing pressure is also reduced because of cushion effect of compressible air. Due to high viscosity damping effect and compressible air effect, the rising time of impact pressure becomes longer. It is also found that liquid viscosity and compressible air influence distribution of dynamic pressure along the vertical tank wall.

  11. Implementing a Compressed Air System Leak Management Program at an Automotive Plant (Visteon's Monroe Plant)

    SciTech Connect

    2001-01-01

    The energy team at Visteon’s Monroe plant, formerly owned by Ford Motor Company, implemented an ongoing compressed air system leak management program. The team developed an approach that combined a traditional “find and fix” effort with an innovative implementation and marketing program. As a result of the leak management program, compressed air system consumption was reduced by more than 50% on a per production unit basis.

  12. Canandaigua Wines: Compressed Air System Upgrade Saves Energy and Improves Performance at a Winery

    SciTech Connect

    2005-03-01

    In June 2004, Canandaigua Wine Company (CWC) completed an upgrade project on the compressed air system at its winery in Lodi, California. Before the project, the winery depended on two compressors to satisfy its production requirements. Anticipating an expansion of its production capacity, the winery commissioned a review of the compressed air system by a U.S. Department of Energy (DOE) Qualifi ed AIRMaster+ Specialist at Atlas Copco Compressors, Inc.

  13. Compression-ignition Engine Performance at Altitudes and at Various Air Pressures and Temperatures

    NASA Technical Reports Server (NTRS)

    Moore, Charles S; Collins, John H

    1937-01-01

    Engine test results are presented for simulated altitude conditions. A displaced-piston combustion chamber on a 5- by 7-inch single cylinder compression-ignition engine operating at 2,000 r.p.m. was used. Inlet air temperature equivalent to standard altitudes up to 14,000 feet were obtained. Comparison between performance at altitude of the unsupercharged compression-ignition engine compared favorably with the carburetor engine. Analysis of the results for which the inlet air temperature, inlet air pressure, and inlet and exhaust pressure were varied indicates that engine performance cannot be reliably corrected on the basis of inlet air density or weight of air charge. Engine power increases with inlet air pressure and decreases with inlet air temperatures very nearly as straight line relations over a wide range of air-fuel ratios. Correction factors are given.

  14. Compressed Air System Survey at Sierra Army Depot, CA

    DTIC Science & Technology

    2000-11-01

    time. Each station uses a paint gun (mostly HVLP guns with a capacity of 5 SCFM are used, but occasionally HPLV guns with a capacity of 8 SCFM may be...SCFM. d. Air release from the two CO monitors for a total of 30 SCFM. e. Occasional application of air guns , one unit at a given time, 5 SCFM...a. This shop used various types of air tools. The major air users in- clude air hammers, drills, sanders, air guns , and impact wrenches. Pneumatic

  15. Compressed Air System Improvements Increase Production at a Tin Mill (Weirton Plant)

    SciTech Connect

    2000-12-01

    In 1999, Weirton Steel completed a project in which the compressed air system at their tin mill in Weirton, West Virginia was completely overhauled. The installation of new compressors, the addition of air treatment equipment, and the repair of leaks significantly reduced compressor shutdowns, production downtime, and product rejects.

  16. Improving Compressed Air Energy Efficiency in Automotive Plants - Practical Examples and Implementation

    SciTech Connect

    Alkadi, Nasr E; Kissock, Professor Kelly

    2011-01-01

    The automotive industry is the largest industry in the United States in terms of the dollar value of production [1]. U.S. automakers face tremendous pressure from foreign competitors, which have an increasing manufacturing presence in this country. The Big Three North American Original Equipment Manufacturers (OEMs) General Motors, Ford, and Chrysler are reacting to declining sales figures and economic strain by working more efficiently and seeking out opportunities to reduce production costs without negatively affecting the production volume or the quality of the product. Successful, cost-effective investment and implementation of the energy efficiency technologies and practices meet the challenge of maintaining the output of high quality product with reduced production costs. Automotive stamping and assembly plants are typically large users of compressed air with annual compressed air utility bills in the range of $2M per year per plant. This paper focuses on practical methods that the authors have researched, analyzed and implemented to improve compressed air system efficiency in automobile manufacturing facilities. It describes typical compressed air systems in automotive stamping and assembly plants, and compares these systems to best practices. The paper then presents a series of examples, organized using the method of inside-out approach, which strategically identifies the energy savings in the compressed air system by first minimizing end-use demand, then minimizing distribution losses, and finally making improvements to primary energy conversion equipment, the air compressor plant.

  17. Effect of a Shear Layer on the Stability of an Axisymmetric External Compression Air Intake,

    DTIC Science & Technology

    1985-10-21

    ID , E = OF A SHEAR LAY ON THE STABILITY OF AN AXISYI4~M=C EXTERNAL QYM2RESSION AIR INTAKE by Z. Kunyuan, Y. Shaozhi, P. Chenyi Approved for public...t 110E 4 EFFECT OF A SItEAR LAYER ON THE STABILITY OF AN AXISYMMETRICEXTERNAL COMPRESSION AIR INTAKE Zhang Kunyuan, Yu Shaozhi, Peng Chenyi (Nanjing...positions on the stability of a variable center cone external compression air intake under the condition of a M 1.72 incident stream. It was experimentally

  18. Application of P4 Polyphase codes pulse compression method to air-coupled ultrasonic testing systems.

    PubMed

    Li, Honggang; Zhou, Zhenggan

    2017-07-01

    Air-coupled ultrasonic testing systems are usually restricted by low signal-to-noise ratios (SNR). The use of pulse compression techniques based on P4 Polyphase codes can improve the ultrasound SNR. This type of codes can generate higher Peak Side Lobe (PSL) ratio and lower noise of compressed signal. This paper proposes the use of P4 Polyphase sequences to code ultrasound with a NDT system based on air-coupled piezoelectric transducer. Furthermore, the principle of selecting parameters of P4 Polyphase sequence for obtaining optimal pulse compression effect is also studied. Successful results are presented in molded composite material. A hybrid signal processing method for improvement in SNR up to 12.11dB and in time domain resolution about 35% are achieved when compared with conventional pulse compression technique. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Study of hydraulic air compression for Ocean Thermal Energy Conversion open-cycle application

    NASA Astrophysics Data System (ADS)

    Golshani, A.; Chen, F. C.

    1983-01-01

    A hydraulic air compressor, which requires no mechanical moving parts and operates in a nearly isothermal mode, can be an alternative for the noncondensible gas disposal of an Ocean Thermal Energy Conversion (OTEC) open-cycle power system. The compressor requires only a downward flow of water to accomplish air compression. An air compressor test loop was assembled and operated to obtain test data that would lead to the design of an OTEC hydraulic air compressor. A one dimensional, hydraulic gas compressor, computer model was employed to simulate the laboratory experiments, and it was tuned to fit the test results. A sensitivity study that shows the effects of various parameters on the applied head of the hydraulic air compression is presented.

  20. Transconjunctival orbital emphysema caused by compressed air injury: A case report

    PubMed Central

    Vasu, Usha; Francis, Febson; Nazareth, Colin

    2008-01-01

    Orbital emphysema following conjunctival tear in the absence of orbital wall fracture, caused by air under pressure is rare. Usually orbital emphysema is seen in facial trauma associated with damage to the adjacent paranasal sinuses or facial bones. To the best of our knowledge, there have been only eight reports of orbital emphysema following use of compressed air during industrial work. The air under pressure is pushed through the subconjunctival space into the subcutaneous and retrobulbar spaces. We present here a rare cause of orbital emphysema in a young man working with compressed air gun. Although the emphysema was severe, there were no orbital bone fracture and the visual recovery of the patient was complete without attendant complications. PMID:18417833

  1. Demonstration of Isothermal Compressed Air Energy Storage to Support Renewable Energy Production

    SciTech Connect

    Bollinger, Benjamin

    2015-01-02

    This project develops and demonstrates a megawatt (MW)-scale Energy Storage System that employs compressed air as the storage medium. An isothermal compressed air energy storage (ICAESTM) system rated for 1 MW or more will be demonstrated in a full-scale prototype unit. Breakthrough cost-effectiveness will be achieved through the use of proprietary methods for isothermal gas cycling and staged gas expansion implemented using industrially mature, readily-available components.The ICAES approach uses an electrically driven mechanical system to raise air to high pressure for storage in low-cost pressure vessels, pipeline, or lined-rock cavern (LRC). This air is later expanded through the same mechanical system to drive the electric motor as a generator. The approach incorporates two key efficiency-enhancing innovations: (1) isothermal (constant temperature) gas cycling, which is achieved by mixing liquid with air (via spray or foam) to exchange heat with air undergoing compression or expansion; and (2) a novel, staged gas-expansion scheme that allows the drivetrain to operate at constant power while still allowing the stored gas to work over its entire pressure range. The ICAES system will be scalable, non-toxic, and cost-effective, making it suitable for firming renewables and for other grid applications.

  2. Light-weight extension tubes for compressed-air garden sprayers

    Treesearch

    Thomas W. McConkey; Charles E. Swett

    1967-01-01

    To hand-spray taller trees safely and efficiently, 8-, 12-, and 16-foot extension tubes for compressed-air garden sprayers were designed and built. These light-weight tubes have been used successfully for spraying white pine leaders for weevil control on the Massabesic Experimental Forest in Maine. Bill of materials and assembly instructions are included.

  3. Compressed Air System Retrofitting Project Improves Productivity at a Foundry (Cast Masters, Bowling Green, OH)

    SciTech Connect

    2002-06-01

    This case study highlights International Truck and Engine Corporation's optimization project on the compressed air system that serves its foundry, Indianapolis Casting Corporation. Due to the project's implementation, the system's efficiency was greatly improved, allowing the foundry to operate with less compressor capacity, which resulted in reduced energy consumption, significant maintenance savings, and more reliable production.

  4. Compressed Air System Optimization Project Improves Production at a Metal Forging Plant (Modern Forge, TN, Plant)

    SciTech Connect

    2000-12-01

    In 1995, Modern Forge of Tennessee implemented a compressed air system improvement project at its Piney Flats, Tennessee, forging plant. Due to the project’s implementation, the plant was able to operate with fewer compressors and improve its product quality, thus allowing it to increase productivity. The project also resulted in considerable energy and maintenance savings.

  5. Improving Energy Efficiency of Compressed Air System Based onSystem Audit

    SciTech Connect

    Shanghai, Hongbo Qin; McKane, Aimee

    2007-06-01

    Industrial electric motor systems consume more than 600billion kWh annually, accounting for more than 50 percent of China selectricity use. The International Energy Agency estimates thatoptimizing motor systems results in an improvement of 20-25 percent,which is well-supported by experience in both the U.S. and China.Compressed air systems in China use 9.4 percent of all electricity.Compressed air use in China is growing rapidly, as new industrial plantsare built and the production processes of existing plants expand andchange. Most of these systems, whether existing or new, are not optimizedfor energy efficiency. This paper will present a practitioner'sperspective on theemergence of compressed air auditing services inChina, specifically as it pertains to Shanghai and surrounding areas.Both the methodology used and the market development of these compressedair system services will be addressed. Finally, the potential for energysaving opportunities will be described based on highlights from over 50compressed air system energy audits completed by Shanghai EnergyConservation Service Center, both during the United Nations IndustrialDevelopment Organization (UNIDO) China Motor System Energy ConservationProgram, and after this training program was completed.

  6. Compressed Air System Upgrade Improves Production at an Automotive Glass Plant

    SciTech Connect

    Not Available

    2003-02-01

    In 2000, The Visteon automotive glass plant improved its compressed air system at its automotive glass plant in Nashville, Tennessee. This improvement allowed Visteon to save $711,000 annually, reduce annual energy consumption by 7.9 million kilowatt-hours, reduce maintenance, improve system performance, and avoid $800,000 in asbestos abatement costs.

  7. Electric power generating plant having direct-coupled steam and compressed-air cycles

    DOEpatents

    Drost, M.K.

    1981-01-07

    An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

  8. Electric power generating plant having direct coupled steam and compressed air cycles

    DOEpatents

    Drost, Monte K.

    1982-01-01

    An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

  9. Compressed Air System Improvement Project Saves Foundry Energy and Increases Production

    SciTech Connect

    2002-05-01

    This case study highlights International Truck and Engine Corporation's optimization project on the compressed air system that serves its foundry, Indianapolis Casting Corporation. Due to the project's implementation, the system's efficiency was greatly improved, allowing the foundry to operate with less compressor capacity, which resulted in reduced energy consumption, significant maintenance savings, and more reliable production.

  10. Proctor & Gamble: Compressed Air System Upgrade Saves Energy & Improves Production at a Paper Mill

    SciTech Connect

    2004-05-01

    In 2002, Procter & Gamble applied a system-level strategy to optimize a compressed air system at its paper products mill in Mehoopany, Pennsylvania. The project improved production, improved system performance, and saved 7.6 million kWh per year and $309,000 per year in maintenance costs.

  11. Safety in the use of compressed air versus oxygen for the ophthalmic patient.

    PubMed

    Rodgers, Laura A; Kulwicki, Anahid

    2002-02-01

    Oxygen, routinely administered during surgery to avoid hypoxia, poses risks including increased likelihood of surgical room fires and predisposition to retinal phototoxicity in patients. Compressed air to supplement ventilation may be safer than oxygen. The purpose of this study was to determine whether hypoxia occurs more frequently when compressed air replaces supplemental oxygen during ophthalmic surgery. A convenience sample of 111 patients was randomly assigned to receive supplemental oxygen (group 1) or compressed air (group 2). Patients with serious cardiac or pulmonary disease were excluded. Blood oxygen levels were monitored during surgery by pulse oximetry. Oxygen was administered to all group 2 patients whose oxygen saturation fell to less than 90% or by more than 5% below baseline. No differences were observed between groups in age, ASA classification, type of surgery, or anesthetic drugs or doses. Minor, but statistically higher oxygen values were observed in group 1. The frequency with which oxygen saturation decreased below 90% or below 5% of baseline was similar in both groups. Supplemental oxygen is not required routinely in selected patients undergoing ophthalmic surgery. By using compressed air, the risk of operating room fires and retinal phototoxicity may be reduced.

  12. Compressed-Air Energy Storage: Preliminary design and site development program in an aquifer. Volume 1: Executive summary

    NASA Astrophysics Data System (ADS)

    McCafferty, T. W.; Walke, W. C.; Bonk, J. S.

    1981-07-01

    The behavior and suitability of an aquifer-based compressed air energy storage (CAES) facility were investigated. The project was part of a five-phase program to promote compressed air energy storage and underground pumped hydro in the United States. The background, project organization, and summarization of all project work are provided.

  13. Two stroke homogenous charge compression ignition engine with pulsed air supplier

    DOEpatents

    Clarke, John M.

    2003-08-05

    A two stroke homogenous charge compression ignition engine includes a volume pulsed air supplier, such as a piston driven pump, for efficient scavenging. The usage of a homogenous charge tends to decrease emissions. The use of a volume pulsed air supplier in conjunction with conventional poppet type intake and exhaust valves results in a relatively efficient scavenging mode for the engine. The engine preferably includes features that permit valving event timing, air pulse event timing and injection event timing to be varied relative to engine crankshaft angle. The principle use of the invention lies in improving diesel engines.

  14. Potential hazards of compressed air energy storage in depleted natural gas reservoirs.

    SciTech Connect

    Cooper, Paul W.; Grubelich, Mark Charles; Bauer, Stephen J.

    2011-09-01

    This report is a preliminary assessment of the ignition and explosion potential in a depleted hydrocarbon reservoir from air cycling associated with compressed air energy storage (CAES) in geologic media. The study identifies issues associated with this phenomenon as well as possible mitigating measures that should be considered. Compressed air energy storage (CAES) in geologic media has been proposed to help supplement renewable energy sources (e.g., wind and solar) by providing a means to store energy when excess energy is available, and to provide an energy source during non-productive or low productivity renewable energy time periods. Presently, salt caverns represent the only proven underground storage used for CAES. Depleted natural gas reservoirs represent another potential underground storage vessel for CAES because they have demonstrated their container function and may have the requisite porosity and permeability; however reservoirs have yet to be demonstrated as a functional/operational storage media for compressed air. Specifically, air introduced into a depleted natural gas reservoir presents a situation where an ignition and explosion potential may exist. This report presents the results of an initial study identifying issues associated with this phenomena as well as possible mitigating measures that should be considered.

  15. Improving the performance of a compression ignition engine by directing flow of inlet air

    NASA Technical Reports Server (NTRS)

    Kemper, Carlton

    1946-01-01

    The object of this report is to present the results of tests performed by the National Advisory Committee for Aeronautics to determine the effect on engine performance of directing the flow of the inlet air to a 5-inch by 7-inch cylinder, solid injection, compression ignition engine, After a few preliminary tests, comparative runs were made at a speed of 1500 r.p.m. with and without directed air flow. It was found that directing the flow of the inlet air toward the fuel injection valve gave steadier engine operation, and an appreciable increase in power, and decreased fuel consumption. The results indicate the possibility of improving the performance of a given type of combustion chamber without changing its shape and with no change in valve timing. They would also seem to prove that directional turbulence, set up before the inlet valve of a four-stroke cycle engine, continues in the engine cylinder throughout the compression stroke.

  16. Air-coupled ultrasonic spectroscopy of highly damping materials using pulse compression.

    PubMed

    Pallav, Prakash; Hutchins, David A; Yin, Xiaokang

    2009-06-01

    Air-coupled ultrasonic spectroscopy is described, whereby the output from a pulse compression system is used. It is demonstrated that the cross-correlation operation used within a pulse-compression system preserves amplitude and phase information. This approach allows the signal-to-noise ratio and, hence, signal-detection capability to be improved by the cross-correlation, while allowing noncontact spectral information for solid samples to be obtained. Results are presented for chocolate samples, where measurements of interest to the food industry have been obtained.

  17. Compressed air energy storage system two-phase flow experiment

    SciTech Connect

    Kumamaru, Hiroshige; Ohtsu, Iwao; Murata, Hideo

    1996-08-01

    A water/CO{sub 2}-combination test facility, having a vertical shaft height of {approximately} 25 m and a shaft inner diameter of 0.2 m, has been constructed in simulating a water/air full-size CAES system, having a shaft height of {approximately} 1,000 m and an inner diameter of {approximately} 3 m. Totally fifteen experiments have been performed in this test facility. In an experiment of CO{sub 2} high-concentration ({approximately} 0.4 MPa) and medium water injection velocity ({approximately} 0.5 m/s), the shaft void fraction during gas charging to a lower reservoir (i.e. during water injection to the shaft) became highest in all the experiment. This experiment may correspond to the severest situation in a full-size CAES system; however, the blowout did not occur in this experiment. In an experiment of CO{sub 2} high-concentration({approximately} 0.4 MPa) and very-high injection velocity ({approximately} 2.5 m/s), after gas charging stopped, CO{sub 2}-supersaturated water, remained in the shaft, formed bubbles vigorously, and thereafter the blowout occurred. However, the injection velocity of {approximately} 2.5 m/s corresponds to a velocity of {approximately} 100 m/s in a full-size CAES system and may be unreal.

  18. Compressed Air System Overhaul Improves Production at a Powdered Metal Manufacturing Plant (GKN Sinter Metals in Salem, IN)

    SciTech Connect

    2000-11-01

    In 1998, GKN Sinter Metals completed a successful compressed air system improvement project at its Salem, Indiana manufacturing facility. The project was performed after GKN undertook a survey of its system in order to solve air quality problems and to evaluate whether the capacity of their compressed air system would meet their anticipated plant expansion. Once the project was implemented, the plant was able to increase production by 31% without having to add any additional compressor capacity.

  19. Engineering and economic evaluation of integrated gasification compressed air storage with humidification (IGCASH). Final report

    SciTech Connect

    Ghaly, O.; McCone, A.; Nakhamkin, M.; Patel, M.

    1993-11-01

    Integrated Gasification Compressed Air Storage with Humidification (IGCASH) is concept for an intermediate-load, cycling-duty plant with the environmental advantages of coal gasification and the reliability benefits of continuous operation of the hot gasification and turbomachinery equipment. The IGCASH concept integrates a quench-type coal gasification system with an advanced compressed air storage system in which the compression heat is recovered and stored in water which is used to humidify and preheat the air and fuel gas sent to the turbine. Bechtel under contract to EPRI (RP 2834-3) performed an engineering and economic evaluation to verify the feasibility of IGCASH as an option for intermediate-load power generation from coal. A baseline design was developed for a conceptual 400 MW generic IGCASH plant using currently available technology, including the Texaco full-quench gasification process, Westinghouse turbomachinery, and solution-mined salt-dome cavern for air storage. Three alternatives to the baseline design were also developed to assess the effects of storage water temperature and next-generation turbomachinery on plant performance and economics. The IGCASH concept compared favorably with conventional pulverized coal fired steam (PCFS) power generation. The IGCASH baseline design showed a significantly lower heat rate and yielded a lower cost of electricity than a comparable PCFS plant operating on the same duty cycle.

  20. Changes in lung function after working with the shotcrete lining method under compressed air conditions.

    PubMed Central

    Kessel, R; Redl, M; Mauermayer, R; Praml, G J

    1989-01-01

    Shotcrete techniques under compressed air are increasingly applied in the construction of tunnels. Up to now little is known about the influence of shotcrete dusts on the function of the lung. The lung function of 30 miners working with shotcrete under compressed air (before and after one shift) was measured. They carried personal air samplers to assess the total dust exposure. Long term effects were studied on a second group of 29 individuals exposed to shotcrete dusts and compressed air for two years. A significant increase of airway resistance and a significant decrease of some flow-volume parameters were found after one workshift. These changes partially correlate close to the dust exposure. After two years exposure a significant decrease of mean expiratory flow (MEF)50 and MEF25 was found. These results point to damage in the small airways and emphasise the major role of the lung function test--including the flow-volume manoeuvre for the medical examination of the workers. Additionally, they should carry filter masks. Images PMID:2923823

  1. Changes in lung function after working with the shotcrete lining method under compressed air conditions.

    PubMed

    Kessel, R; Redl, M; Mauermayer, R; Praml, G J

    1989-02-01

    Shotcrete techniques under compressed air are increasingly applied in the construction of tunnels. Up to now little is known about the influence of shotcrete dusts on the function of the lung. The lung function of 30 miners working with shotcrete under compressed air (before and after one shift) was measured. They carried personal air samplers to assess the total dust exposure. Long term effects were studied on a second group of 29 individuals exposed to shotcrete dusts and compressed air for two years. A significant increase of airway resistance and a significant decrease of some flow-volume parameters were found after one workshift. These changes partially correlate close to the dust exposure. After two years exposure a significant decrease of mean expiratory flow (MEF)50 and MEF25 was found. These results point to damage in the small airways and emphasise the major role of the lung function test--including the flow-volume manoeuvre for the medical examination of the workers. Additionally, they should carry filter masks.

  2. Fuel Spray and Flame Formation in a Compression-Ignition Engine Employing Air Flow

    NASA Technical Reports Server (NTRS)

    Rothrock, A M; Waldron, C D

    1937-01-01

    The effects of air flow on fuel spray and flame formation in a high-speed compression-ignition engine have been investigated by means of the NACA combustion apparatus. The process was studied by examining high-speed motion pictures taken at the rate of 2,200 frames a second. The combustion chamber was of the flat-disk type used in previous experiments with this apparatus. The air flow was produced by a rectangular displacer mounted on top of the engine piston. Three fuel-injection nozzles were tested: a 0.020-inch single-orifice nozzle, a 6-orifice nozzle, and a slit nozzle. The air velocity within the combustion chamber was estimated to reach a value of 425 feet a second. The results show that in no case was the form of the fuel spray completely destroyed by the air jet although in some cases the direction of the spray was changed and the spray envelope was carried away by the moving air. The distribution of the fuel in the combustion chamber of a compression-ignition engine can be regulated to some extent by the design of the combustion chamber, by the design of the fuel-injection nozzle, and by the use of air flow.

  3. Simple Expressions to Predict Actual Performance of Vapor Compression Air-conditioner Concerning Heat Island Analysis

    NASA Astrophysics Data System (ADS)

    Shinomiya, Naruaki; Nishimura, Nobuya; Iyota, Hiroyuki

    Simple expressions to predict actual performance of vapor compression air-conditioners such as room air-conditioners and multi-split type air-conditioners are proposed. Coefficient of performance is expressed in these simple expressions as a function of outdoor temperature, indoor temperature, air-conditioning load rate, air flow rate of indoor unit (in case of room air-conditioners) and difference in height between indoor unit and outdoor unit (in case of multi-split type air-conditioners). Those simple expressions are obtained by neural net work analysis (Rule extraction method from facts, RF5). Actual performance of air-conditioners which are used for training data and teaching data of net work are obtained by numerical simulations developed by the authors. Calculation results of these simple expressions usually agree with experimental values of other researchers. Furthermore, amount of exhaust heat from air-conditioners calculated with these expressions are 10% or lower than traditional approach: calculated with constant value of coefficient of performance.

  4. Compressed air energy storage: Preliminary design and site development program in an aquifer. Volume 2: Utility system planning

    NASA Astrophysics Data System (ADS)

    1981-07-01

    The performance of an aquifer compressed air energy storage system was studied. The benefits derived from the integration of a compressed air energy storage facility with a hypothetical electrical network are analyzed. Scenarios of 100 percent coal, 50 percent coal and 50 percent nuclear, and 100 percent nuclear base load capacity additions were examined. Favorable economics are indicated when compressed air energy storage is installed as an alternative to combustion turbine peaking capacity on a system with a significant amount of oil fired generation.

  5. System Engineering Analysis of Compressed Air Systems Installed on LHA-1 and LPH-2 Class Ships,

    DTIC Science & Technology

    1982-07-01

    MAINTENANCE HISTORY (SARP) Number Receiving Class B/C Overhaul ROH Hull Class B Class C Completion Number Overhauis Repairs H/MPAC Percentage LPAC ...worn fourth-stage suction and discharge valves; and 144 for wiped connecting rod bearings, scored wrist pins, and crankshafts. The HPAC and LPAC ...COMNAVSURFPACINST inspection requirements, should be adequate to main- tain the system. PMS requirements for the compressed air system ( LPAC , MPAC

  6. The effect of compressed air foam on the detection of hydrocarbon fuels in fire debris samples.

    PubMed

    Coulson, S A; Morgan-Smith, R K; Noble, D

    2000-01-01

    In 1998/99 the New Zealand Fire Service implemented compressed air foam delivery systems for the suppression of fires in rural areas. This study investigated whether the introduction of the foam to the seat of the fire created any problems in subsequent analyses of fire debris samples. No significant interferences from the foam were found when the samples were analysed by direct headspace using activated carbon strips. The only foam component detected was limonene.

  7. One-Year Results for the Kelly Air Force Base Compressed Work Week Survey

    DTIC Science & Technology

    1994-01-01

    home and at work, resulting in social stability. 14. SUBJECT TERMS 15. NUMBER OF PAGES Compressed Work Week Lifestyle .44 Attitude Survey Air Force Base...for 1-year. Few published studies have investigated the impact of CWS on the lifestyle or quality of life of the employee, particularly over extended...grouped into lifestyle subcategories (family, community, health, leisure, social, cultural, sleep, and finances) or job related subcategories

  8. Six-Month Results for the Kelly Air Force Base Compressed Work Week Survey

    DTIC Science & Technology

    1993-07-01

    14. SUBJECT TERMS 15. NUMBER OF PAGES Air Force Base workers Compressed work week 60 Attitude survey Lifestyle 16. PRICE CODE 17. SECURITY...10 APPENDIX A The Kelly AFB Attitude Survey ................. 13 B Responses to the Lifestyle and Job Relat i Questions (1-91) on the Survey (Sections...on CWS for a 6-month period. There are few published studies regarding the impact of CWS on the lifestyle or quality of life of the employee

  9. Geothermal well behaviour prediction after air compress stimulation using one-dimensional transient numerical modelling

    NASA Astrophysics Data System (ADS)

    Yusman, W.; Viridi, S.; Rachmat, S.

    2016-01-01

    The non-discharges geothermal wells have been a main problem in geothermal development stages and well discharge stimulation is required to initiate a flow. Air compress stimulation is one of the methods to trigger a fluid flow from the geothermal reservoir. The result of this process can be predicted by using by the Af / Ac method, but sometimes this method shows uncertainty result in several geothermal wells and also this prediction method does not take into account the flowing time of geothermal fluid to discharge after opening the well head. This paper presents a simulation of non-discharges well under air compress stimulation to predict well behavior and time process required. The component of this model consists of geothermal well data during heating-up process such as pressure, temperature and mass flow in the water column and main feed zone level. The one-dimensional transient numerical model is run based on the Single Fluid Volume Element (SFVE) method. According to the simulation result, the geothermal well behavior prediction after air compress stimulation will be valid under two specific circumstances, such as single phase fluid density between 1 - 28 kg/m3 and above 28.5 kg/m3. The first condition shows that successful well discharge and the last condition represent failed well discharge after air compress stimulation (only for two wells data). The comparison of pf values between simulation and field observation shows the different result according to the success discharge well. Time required for flow to occur as observed in well head by using the SFVE method is different with the actual field condition. This model needs to improve by updating more geothermal well data and modified fluid phase condition inside the wellbore.

  10. CAESCAP: A computer code for compressed-air energy-storage-plant cycle analysis

    NASA Astrophysics Data System (ADS)

    Fort, J. A.

    1982-10-01

    The analysis code, CAESCAP, was developed as an aid in comparing and evaluating proposed compressed air energy storage (CAES) cycles. Input consists of component parameters and working fluid conditions at points along a cycle. The code calculates thermodynamic properties at each point and then calculates overall cycle performance. Working fluid capabilities include steam, air, nitrogen, and parahydrogen. The CAESCAP code was used to analyze a variety of CAES cycles. The combination of straightforward input and flexible design make the code easy and inexpensive to use.

  11. AEC brings new technology to US: Compressed air provides peaking power

    SciTech Connect

    Not Available

    1989-09-01

    The first power plant utilizing compressed air energy storage technology (CAES) in the United States is being built by Alabama Electric Cooperative near McIntosh, Alabama. CAES technology, which stores pressurized air in underground chambers during periods of low power demand for generating power during high demand periods, is capable of producing up to three times more power per BTU of fuel burned than conventional gas turbine generators. A 19 million-cubic foot air storage cavern is being excavated in a salt dome 1,400 feet underground for the 110 MW McIntosh plant. Once finished, the cavern is expected to be 200 feet in diameter and 600 feet deep, storing enough air to operate the generator for 26 consecutive hours.

  12. Increasing the Air Charge and Scavenging the Clearance Volume of a Compression-Ignition Engine

    NASA Technical Reports Server (NTRS)

    Spanogle, J A; Hicks, C W; Foster, H H

    1934-01-01

    The object of the investigation presented in this report was to determine the effects of increasing the air charge and scavenging the clearance volume of a 4-stroke-cycle compression-ignition engine having a vertical-disk form combustion chamber. Boosting the inlet-air pressure with normal valve timing increased the indicated engine power in proportion to the additional air inducted and resulted in smoother engine operation with less combustion shock. Scavenging the clearance volume by using a valve overlap of 145 degrees and an inlet-air boost pressure of approximately 2 1/2 inches of mercury produced a net increase in performance for clear exhaust operation of 33 percent over that obtained with normal valve timing and the same boost pressure. The improved combustion characteristics result in lower specific fuel consumption, and a clearer exhaust.

  13. Compressed air energy storage in depleted natural gas reservoirs: effects of porous media and gas mixing

    NASA Astrophysics Data System (ADS)

    Oldenburg, C. M.; Pan, L.

    2015-12-01

    Although large opportunities exist for compressed air energy storage (CAES) in aquifers and depleted natural gas reservoirs, only two grid-scale CAES facilities exist worldwide, both in salt caverns. As such, experience with CAES in porous media, what we call PM-CAES, is lacking and we have relied on modeling to elucidate PM-CAES processes. PM-CAES operates similarly to cavern CAES. Specifically, working gas (air) is injected through well(s) into the reservoir compressing the cushion gas (existing air in the reservoir). During energy recovery, high-pressure air from the reservoir flows first into a recuperator, then into an expander, and subsequently is mixed with fuel in a combustion turbine to produce electricity, thereby reducing compression costs. Energy storage in porous media is complicated by the solid matrix grains which provide resistance to flow (via permeability in Darcy's law); in the cap rock, low-permeability matrix provides the seal to the reservoir. The solid grains also provide storage capacity for heat that might arise from compression, viscous flow effects, or chemical reactions. The storage of energy in PM-CAES occurs variably across pressure gradients in the formation, while the solid grains of the matrix can release/store heat. Residual liquid (i.e., formation fluids) affects flow and can cause watering out at the production well(s). PG&E is researching a potential 300 MW (for ten hours) PM-CAES facility in a depleted gas reservoir near Lodi, California. Special considerations exist for depleted natural gas reservoirs because of mixing effects which can lead to undesirable residual methane (CH4) entrainment and reactions of oxygen and CH4. One strategy for avoiding extensive mixing of working gas (air) with reservoir CH4 is to inject an initial cushion gas with reduced oxygen concentration providing a buffer between the working gas (air) and the residual CH4 gas. This reduces the potential mixing of the working air with the residual CH4

  14. Technical and economic assessment of fluidized-bed-augmented compressed-air energy-storage system. Volume 1: Executive summary

    NASA Astrophysics Data System (ADS)

    Giramonti, A. J.; Lessard, R. D.; Merrick, D.; Hobson, M. J.

    1981-09-01

    An energy storage system for electric utility peak load applications is a modified gas turbine power system utilizing underground storage of very high pressure air. The compressed air energy storage (CAES) concept involves using off peak electricity generated from indigenous coal or nuclear sources to compress air, storing the air in large underground facilities, and withdrawing the air during peak load periods when it would be heated by combustion and expanded through gas turbines to generate power. The attractiveness of the CAES concept is based upon its potential to supply competitively priced peaking energy, to reduce peak load power plant dependence on petroleum based fuels, and to provide a means for leveling the utility system load demand. Therefore, a technical and economic assessment of coal fired fluidized bed combustor/compressed air energy storage systems was performed and is described.

  15. Ford Van Dyke: Compressed Air Management Program Leads to Improvements that Reduce Energy Consumption at an Automotive Transmission Plant

    SciTech Connect

    2010-06-25

    Staff at the Ford Van Dyke Transmission Plant in Sterling Heights, Michigan, have increased the efficiency of the plant’s compressed air system to enhance its performance while saving energy and improving production.

  16. Evaluation of thermal energy storage materials for advanced compressed air energy storage systems

    SciTech Connect

    Zaloudek, F.R.; Wheeler, K.R.; Marksberry, L.

    1983-03-01

    Advanced Compressed-Air Energy Storage (ACAS) plants have the near-term potential to reduce the fuel consumption of compressed-air plants from 33 to 100%, depending upon their design. Fuel is saved by storing some or all of the heat of compression as sensible heat which is subsequently used to reheat the compressed air prior to expansion in the turbine generator. The thermal storage media required for this application must be low cost and durable. The objective of this project was to screen thermal store materials based on their thermal cycle durability, particulate formation and corrosion resistant characteristics. The materials investigated were iron oxide pellets, Denstone pebbles, cast-iron balls, and Dresser basalt rock. The study specifically addressed the problems of particle formation and thermal ratcheting of the materials during thermal cycling and the chemical attack on the materials by the high temperature and moist environment in an ACAS heat storage bed. The results indicate that from the durability standpoint Denstone, cast iron containing 27% or more chromium, and crushed Dresser basalt would possibly stand up to ACAS conditions. If costs are considered in addition to durability and performance, the crushed Dresser basalt would probably be the most desirable heat storage material for adiabatic and hybrid ACAS plants, and more in-depth longer term thermal cycling and materials testing of Dresser basalt is recommended. Also recommended is the redesign and costing analysis of both the hybrid and adiabatic ACAS facilities based upon the use of Dresser basalt as the thermal store material.

  17. Compressed air energy storage preliminary design and site development program in an aquifer. Turbomachinery design

    NASA Astrophysics Data System (ADS)

    Berman, P. A.; Bonk, J. S.; Kobett, W. F.; Kosanovich, N. S.; Long, L. J.; Marinacci, D. J.

    1981-07-01

    Compressed Air Energy Storage (CAES) is a means of storing electrical energy generated by utility baseload power plants during off-peak hours. This stored energy will be used during periods of high demand. Compressed Air Energy Storage (CAES) system uses off-peak power from an electrical grid to operate an electric dynamo. This is used as a motor to drive a compressor train that charges atmospheric air at elevated pressure into an underground aquifer. During high electrical demand periods, the pressurized air is withdrawn from the aquifer and channeled to combustors where it is heated and then expanded through a combustion turbine. The turbine drives the electric dynamo, being operated as a generator, to supply power back to the grid. Since the CAES turbine train is divorced from the compressor during power generation, the net output power is about three times that of a normal combustion turbine. Although the fuel consumption rate is nearly the same, the heat rate is much lower.

  18. Analytical modeling of a hydraulically-compensated compressed-air energy-storage system

    SciTech Connect

    McMonagle, C.A.; Rowe, D.S.

    1982-12-01

    A computer program was developed to calculate the dynamic response of a hydraulically-compensated compressed air energy storage (CAES) system, including the compressor, air pipe, cavern, and hydraulic compensation pipe. The model is theoretically based on the two-fluid model in which the dynamics of each phase are presented by its set of conservation equations for mass and momentum. The conservation equations define the space and time distribution of pressure, void fraction, air saturation, and phase velocities. The phases are coupled by two interface equations. The first defines the rate of generation (or dissolution) of gaseous air in water and can include the effects of supersaturation. The second defines the frictional shear coupling (drag) between the gaseous air and water as they move relative to each other. The relative motion of the air and water is, therefore, calculated and not specified by a slip or drift-velocity correlation. The total CASE system is represented by a nodal arrangement. The conservation equations are written for each nodal volume and are solved numerically. System boundary conditions include the air flow rate, atmospheric pressure at the top of the compensation pipe, and air saturation in the reservoir. Initial conditions are selected for velocity and air saturation. Uniform and constant temperature (60/sup 0/F) is assumed. The analytical model was used to investigate the dynamic response of a proposed system.Investigative calculations considered high and low water levels, and a variety of charging and operating conditions. For all cases investigated, the cavern response to air-charging, was a damped oscillation of pressure and flow. Detailed results are presented. These calculations indicate that the Champagne Effect is unlikely to cause blowout for a properly designed CAES system.

  19. Gas turbine engine adapted for use in combination with an apparatus for separating a portion of oxygen from compressed air

    DOEpatents

    Bland, Robert J [Oviedo, FL; Horazak, Dennis A [Orlando, FL

    2012-03-06

    A gas turbine engine is provided comprising an outer shell, a compressor assembly, at least one combustor assembly, a turbine assembly and duct structure. The outer shell includes a compressor section, a combustor section, an intermediate section and a turbine section. The intermediate section includes at least one first opening and at least one second opening. The compressor assembly is located in the compressor section to define with the compressor section a compressor apparatus to compress air. The at least one combustor assembly is coupled to the combustor section to define with the combustor section a combustor apparatus. The turbine assembly is located in the turbine section to define with the turbine section a turbine apparatus. The duct structure is coupled to the intermediate section to receive at least a portion of the compressed air from the compressor apparatus through the at least one first opening in the intermediate section, pass the compressed air to an apparatus for separating a portion of oxygen from the compressed air to produced vitiated compressed air and return the vitiated compressed air to the intermediate section via the at least one second opening in the intermediate section.

  20. Porous media experience applicable to field evaluation for compressed air energy storage

    SciTech Connect

    Allen, R.D.; Gutknecht, P.J.

    1980-06-01

    A survey is presented of porous media field experience that may aid in the development of a compressed air energy storage field demonstration. Work done at PNL and experience of other groups and related industries is reviewed. An overall view of porous media experience in the underground storage of fluids is presented. CAES experience consists of site evaluation and selection processes used by groups in California, Kansas, and Indiana. Reservoir design and field evaluation of example sites are reported. The studies raised questions about compatibility with depleted oil and gas reservoirs, storage space rights, and compressed air regulations. Related experience embraces technologies of natural gas, thermal energy, and geothermal and hydrogen storage. Natural gas storage technology lends the most toward compressed air storage development, keeping in mind the respective differences between stored fluids, physical conditions, and cycling frequencies. Both fluids are injected under pressure into an aquifer to form a storage bubble confined between a suitable caprock structure and partially displaced ground water. State-of-the-art information is summarized as the necessary foundation material for field planning. Preliminary design criteria are given as recommendations for basic reservoir characteristics. These include geometric dimensions and storage matrix properties such as permeability. Suggested ranges are given for injection air temperature and reservoir pressure. The second step in developmental research is numerical modeling. Results have aided preliminary design by analyzing injection effects upon reservoir pressure, temperature and humidity profiles. Results are reported from laboratory experiments on candidate sandstones and caprocks. Conclusions are drawn, but further verification must be done in the field.

  1. Improving Energy Efficiency in Pharmaceutical ManufacturingOperations -- Part I: Motors, Drives and Compressed Air Systems

    SciTech Connect

    Galitsky, Christina; Chang, Sheng-chien; Worrell, Ernst; Masanet,Eric

    2006-04-01

    In Part I of this two-part series, we focus on efficient use of motors, drives and pumps, both for process equipment and compressed air systems. Pharmaceutical manufacturing plants in the U.S. spend nearly $1 billion each year for the fuel and electricity they need to keep their facilities running (Figure 1, below). That total that can increase dramatically when fuel supplies tighten and oil prices rise, as they did last year. Improving energy efficiency should be a strategic goal for any plant manager or manufacturing professional working in the drug industry today. Not only can energy efficiency reduce overall manufacturing costs, it usually reduces environmental emissions, establishing a strong foundation for a corporate greenhouse-gas-management program. For most pharmaceutical manufacturing plants, Heating, Ventilation and Air Conditioning (HVAC) is typically the largest consumer of energy, as shown in Table 1 below. This two-part series will examine energy use within pharmaceutical facilities, summarize best practices and examine potential savings and return on investment. In this first article, we will focus on efficient use of motors, drives and pumps, both for process equipment and compressed air systems. Part 2, to be published in May, will focus on overall HVAC systems, building management and boilers.

  2. A Dynamic Model of a Vapor Compression Refrigeration Cycle using Zeotropic Refrigerant Mixtures

    NASA Astrophysics Data System (ADS)

    Unezaki, Fumitake; Matsuoka, Fumio

    In order to prove the effectiveness of the developed model, reported in the first report, about dynamics of a vapor compression refrigeration cycle with zeotropic refrigerant mixtures, simulation results are compared with the experimental results obtained for R-407C (R-32/R-125/R-134a=23/25/52wt%).The simulation results are consistent well with the experimental results. As a result of the numerical analysis of dynamic characteristics of composition changing, the variation of compositions in the refrigeration cycle is caused by the variation of the existing compositions of accumulator. The time constant of the composition is approximately equal to the time constant of the pressure and the mass distribution.

  3. Compressed Air System Optimization Project Saves Energy and Improves Production at a Citation Forging Plant

    SciTech Connect

    2003-05-01

    In the 1990s, a subsidiary of the Citation Corporation, Interstate Forging, implemented a compressed air system improvement project at its Milwaukee, Wisconsin, forging plant. This improvement enabled the plant to maintain an adequate and stable pressure level using fewer compressors, which led to improved product quality and lower production downtime. The project also yielded annual energy savings of 820,000 kWh and $45,000. With a total project cost of $67,000, the plant achieved a simple payback of just 1.5 years.

  4. Factors affecting storage of compressed air in solution mined salt cavities

    SciTech Connect

    Allen, R.D.; Doherty, T.J.; Thoms, R.L.

    1982-08-01

    Geologic factors affecting a salt deposit's acceptability for compressed air energy storage include diameter, depth, thickness, mineralogy, strength, presence of gas, faulting, seismic susceptibility, caprock quality, and rate of dissolution by ground water. Assessment of a potential site involves analyzing existing information, seismic surveying, exploratory drilling, examining salt and caprock, geophysical logging, measuring in situ stress, and determining hydrologic impact. Geologic exploration at Huntorf, Federal Republic of Germany, is discussed. Criteria are presented for cavern design parameters, which include octahedral shear strength, excess lateral stress, depth to cavern top, lateral salt thickness, vertical salt thickness, span, and height-todiameter ratio. Cavern, borehole and surface monitoring methods are discussed.

  5. Thermophysical behavior of St. Peter sandstone: application to compressed air energy storage in an aquifer

    SciTech Connect

    Erikson, R.L.

    1983-12-01

    The long-term stability of a sandstone reservoir is of primary importance to the success of compressed air energy storage (CAES) in aquifers. The purpose of this study was to: develop experimental techniques for the operation of the CAES Porous Media Flow Loop (PMFL), an apparatus designed to study the stability of porous media in subsurface geologic environments, conduct experiments in the PMFL designed to determine the effects of temperature, stress, and humidity on the stability of candidate CAES reservoir materials, provide support for the CAES field demonstration project in Pittsfield, Illinois, by characterizing the thermophysical stability of Pittsfield reservoir sandstone under simulated field conditions.

  6. Weyerhaeuser: Compressed Air System Improvement Saves Energy and Improves Production at a Sawmill

    SciTech Connect

    2004-11-01

    In 2000, Weyerhaeuser Company, a U.S. Department of Energy Allied Partner in the Industrial Technologies Program, increased the efficiency of the compressed air system at its sawmill facility in Coburg, Oregon. This improved the system's performance and will save about 1.3 million kWh annually. Total project costs were $55,000; because annual energy cost savings were also $55,000, the simple payback period was only 1 year. Subsequent improvements at six other company plants and mills are yielding 6.8 million kWh in energy savings and reducing annual energy costs by $250,000.

  7. Geotechnical issues and guidelines for storage of compressed air in excavated hard rock caverns

    SciTech Connect

    Allen, R.D.; Doherty, T.J.; Fossum, A.F.

    1982-04-01

    The results of a literature survey on the stability of excavated hard rock caverns are presented. The objective of the study was to develop geotechnical criteria for the design of compressed air energy storage (CAES) caverns in hard rock formations. These criteria involve geologic, hydrological, geochemical, geothermal, and in situ stress state characteristics of generic rock masses. Their relevance to CAES caverns, and the identification of required research areas, are identified throughout the text. This literature survey and analysis strongly suggests that the chief geotechnical issues for the development and operation of CAES caverns in hard rock are impermeability for containment, stability for sound openings, and hydrostatic balance.

  8. Canandaigua Wines: Compressed Air System Upgrade Saves Energy and Improves Performance at a Winery

    SciTech Connect

    Not Available

    2005-03-01

    In June 2004, a U.S. Department of Energy Qualified AIRMaster+ Specialist at Atlas Copco Compressors was asked to review the compressed air system at the Canandaigua Wine Company in Lodi, California, as part of a program to improve industrial energy efficiency. The review prompted a system-level improvement project that enabled the winery to use its compressors more efficiently and to add another, more efficient compressor, saving 218,000 kWh annually and $27,000 in energy and maintenance costs.

  9. Integrated LTCC Pressure/Flow/Temperature Multisensor for Compressed Air Diagnostics†

    PubMed Central

    Fournier, Yannick; Maeder, Thomas; Boutinard-Rouelle, Grégoire; Barras, Aurélie; Craquelin, Nicolas; Ryser, Peter

    2010-01-01

    We present a multisensor designed for industrial compressed air diagnostics and combining the measurement of pressure, flow, and temperature, integrated with the corresponding signal conditioning electronics in a single low-temperature co-fired ceramic (LTCC) package. The developed sensor may be soldered onto an integrated electro-fluidic platform by using standard surface mount device (SMD) technology, e.g., as a standard electronic component would be on a printed circuit board, obviating the need for both wires and tubes and thus paving the road towards low-cost integrated electro-fluidic systems. Several performance aspects of this device are presented and discussed, together with electronics design issues. PMID:22163518

  10. Integrated LTCC pressure/flow/temperature multisensor for compressed air diagnostics.

    PubMed

    Fournier, Yannick; Maeder, Thomas; Boutinard-Rouelle, Grégoire; Barras, Aurélie; Craquelin, Nicolas; Ryser, Peter

    2010-01-01

    We present a multisensor designed for industrial compressed air diagnostics and combining the measurement of pressure, flow, and temperature, integrated with the corresponding signal conditioning electronics in a single low-temperature co-fired ceramic (LTCC) package. The developed sensor may be soldered onto an integrated electro-fluidic platform by using standard surface mount device (SMD) technology, e.g., as a standard electronic component would be on a printed circuit board, obviating the need for both wires and tubes and thus paving the road towards low-cost integrated electro-fluidic systems. Several performance aspects of this device are presented and discussed, together with electronics design issues.

  11. The potential strategic, operating and environmental benefits of TVA's compressed air energy storage (CAES) program

    SciTech Connect

    Bradshaw, D.T.; Brewer, J.E. )

    1992-01-01

    The Tennessee Valley Authority is currently looking at compressed air energy storage (CAES), a new but mature technology, as a new capacity option. The technology is mature because all pieces/components have been in existence and use for over 50 years. The compressors are standard components for the gas industry, and the turbo expander and motor generator are standard components in the utility business. The newness of the CAES technology is due to the integration of these components and the use of underground storage of air in porous media or possibly in abandoned mines. Although the integration of these components is new to the Untied States, they have been demonstrated in Germany for over 10 years in the 290 MWe CAES unit located in a salt cavern near Huntorf, Germany. The CAES unit has been very successful, operating with a 99% start-up reliability, and has been operated remotely.

  12. Gas chromatographic method for measuring nitrogen dioxide and peroxyacetyl nitrate in air without compressed gas cylinders

    SciTech Connect

    Burkhardt, M.R.; Maniga, N.I.; Stedman, D.H.; Paur, R.J.

    1988-04-15

    A gas chromatographic technique that measures atmospheric concentrations of peroxyacetyl nitrate (PAN) and NO/sub 2/ has been developed that uses luminol-based chemiluminescence for detection. The carrier gas is air that has been scrubbed by passing it over FeSO/sub 4/, which eliminates the need for any compressed gas cylinders. A novel gas sampling system and time enable variable sample volumes of contaminated air to be injected. Ambient PAN and NO/sub 2/ measurements can be made every 40 s with detection limits of 0.12 ppb for PAN and 0.2 ppb for NO/sub 2/. Seven other atmospheric species, including ozone, gave no interference. Linear response was observed for NO/sub 2/ from 0.2 to 170 ppb and for PAN from 1 to 70 ppb.

  13. Quantitative Analysis of Major Phytochemicals in Orthodox tea (Camellia sinensis), Oxidized under Compressed Air Environment.

    PubMed

    Panda, Brajesh Kumar; Datta, Ashis Kumar

    2016-04-01

    This study describes major changes in phytochemical composition of orthodox tea (Camellia sinensis var. Assamica) oxidized under compressed air (CA). The experiments for oxidation were conducted under air pressure (101, 202, and 303 kPa) for 150 min. Relative change in the concentrations of caffeine, catechins, theaflavins (TF), and thearubigins (TR) were analyzed. Effect of CA pressure was found to be nonsignificant in regulating caffeine concentration during oxidation. But degradation in different catechins as well as formation of different TF was significantly affected by CA pressure. At high CA pressure, TF showed highest peak value. TR was found to have slower rate of formation during initial phase of oxidation than TF. Even though the rate of TR formation was significantly influenced by CA, a portion of catechins remained unoxidized at end of oxidation. Except caffeine, the percent change in rate of formation or degradation were more prominent at 202 kPa. © 2016 Institute of Food Technologists®

  14. Destratification of an impounding reservoir using compressed air??case of Mudi reservoir, Blantyre, Malawi

    NASA Astrophysics Data System (ADS)

    Chipofya, V. H.; Matapa, E. J.

    This paper reviews the operational and cost effectiveness of a compressed air destratification system that was installed in the Mudi reservoir for destratifying the reservoir. Mudi reservoir is a raw water source for the Blantyre Water Board. It has a capacity of 1,400,000 cubic metres. The reservoir is 15.3 m deep at top water level. In the absence of any artificial circulation of air, the reservoir stratifies into two layers. There is a warm epilimnion in the top 3 m of the reservoir, with temperatures ranging from 23 to 26 °C. There is prolific algal growth in this layer. The bottom layer has much lower temperatures, and is oxygen deficient. Under such anaerobic conditions, ammonia, sulphides, iron and manganese are released from the sediments of the reservoir. As a result of nutrient inflow from the catchments, coupled with tropical ambient temperatures, the reservoir is most times infested with blue-green algae. This results into water treatment problems in respect of taste and odour and iron and manganese soluble salts. To abate such problems, air is artificially circulated in the reservoir, near the intake tower, through a perforated pipe that is connected to an electrically driven compressor. This causes artificial circulation of water in the hypolimnion region of the reservoir. As a result of this circulation, a hostile environment that inhibits the propagation of algae is created. Dissolved oxygen and temperature profiles are practically uniform from top to bottom of reservoir. Concentrations of iron and manganese soluble salts are much reduced at any of the draw-off points available for the water treatment process. The paper concludes by highlighting the significant cost savings in water treatment that are accrued from the use of compressed air destratification in impounding water storage reservoirs for the control of algae and other chemical pollutants.

  15. Carbon and Energy Saving Financial Opportunities in the Industrial Compressed Air Sector

    NASA Astrophysics Data System (ADS)

    Vittorini, Diego; Cipollone, Roberto

    2017-08-01

    The transition towards a more sustainable energy scenario calls for both medium-to-long and short term interventions, with CO2 reduction and fossil fuel saving as main goals for all the Countries in the World. Among all others, one way to support these efforts is the setting-up of immaterial markets able to regulate, in the form of purchase and sales quotas, CO2 emissions avoided and fossil fuels not consumed. As a consequence, the upgrade of those sectors, characterized by high energy impact, is currently more than an option due to the related achievable financial advantage on the afore mentioned markets. Being responsible for about 10% electricity consumption in Industry, the compressed air sector is currently addressed as extremely appealing, when CO2 emissions and burned fossil fuels saving are in question. In the paper, once a standard is defined for compressors performances, based on data from the Compressed Air and Gas Institute and PNEUROP, the achievable energy saving is evaluated along with the effect in terms of CO2 emissions: with reference to those contexts in which mature intangible markets are established, an estimation of the financial benefit from savings sale on correspondent markets is possible, in terms of both avoided CO2 and fossil fuels not burned. The approach adopted allows to extend the analysis results to every context of interest, by applying the appropriate emission factor to the datum on compressor specific consumption.

  16. Thermodynamic analysis of five compressed-air energy-storage cycles. [Using CAESCAP computer code

    SciTech Connect

    Fort, J. A.

    1983-03-01

    One important aspect of the Compressed-Air Energy-Storage (CAES) Program is the evaluation of alternative CAES plant designs. The thermodynamic performance of the various configurations is particularly critical to the successful demonstration of CAES as an economically feasible energy-storage option. A computer code, the Compressed-Air Energy-Storage Cycle-Analysis Program (CAESCAP), was developed in 1982 at the Pacific Northwest Laboratory. This code was designed specifically to calculate overall thermodynamic performance of proposed CAES-system configurations. The results of applying this code to the analysis of five CAES plant designs are presented in this report. The designs analyzed were: conventional CAES; adiabatic CAES; hybrid CAES; pressurized fluidized-bed CAES; and direct coupled steam-CAES. Inputs to the code were based on published reports describing each plant cycle. For each cycle analyzed, CAESCAP calculated the thermodynamic station conditions and individual-component efficiencies, as well as overall cycle-performance-parameter values. These data were then used to diagram the availability and energy flow for each of the five cycles. The resulting diagrams graphically illustrate the overall thermodynamic performance inherent in each plant configuration, and enable a more accurate and complete understanding of each design.

  17. Introduction of a compressed air breathing apparatus for the offshore oil and gas industry.

    PubMed

    Brooks, Chris J; MacDonald, Conor V; Carroll, Joel; Gibbs, Peter N G

    2010-07-01

    When a helicopter ditches the majority of crew and passengers have to make an underwater escape. Some may not be able to hold their breath and will drown. For at least 15 yr, military aircrew have been trained to use a scuba system. In the offshore oil and gas industry, there has been more caution about introducing a compressed air system and a rebreather system has been introduced as an alternative. Recently, Canadian industry and authorities approved the introduction of Helicopter Underwater Emergency Breathing Apparatus (HUEBA) training using compressed air. This communication reports the training of the first 1000 personnel. Training was introduced in both Nova Scotia and Newfoundland concurrently by the same group of instructors. Trainees filled out a questionnaire concerning their perceived ratings of the ease or difficulty of classroom training and the practical use of the HUEBA. Ninety-eight percent of trainees found the classroom and in-water training to be "good/very good". Trainees found it to be "easy/very easy" to clear the HUEBA and breathe underwater in 84% and 64% of cases, respectively. Divers reported a greater ease in learning all the practical uses of the HUEBA except application of the nose clip. There were problems with the nose clip fitting incorrectly, and interference of the survival suit hood with the regulator, which subsequently have been resolved. When carefully applied, the introduction of the HUEBA into training for offshore oil and gas industry helicopter crew and passengers can be safely conducted.

  18. Preliminary engineering design and cost of Advanced Compressed-Air Storage (ACAS) A-5 hybrid

    NASA Astrophysics Data System (ADS)

    Sosnowicz, E. J.; Blackman, J.; Woodhull, A. S.; Zaugg, P.

    1981-08-01

    The advanced compressed air energy (ACAS) plant investiated operates on a partial adiabatic, partial fuel fired cycle. Only a limited advancement in state-of-the-art technology is projected for this hybrid arrangement. The A-5 hybrid systems stores the heat of compression from the low pressure and intermediate pressure compressors in a thermal energy store (TES). The heat collected in the TES is available for preheating the air from the storage cavern prior to its entering the low pressure turbine combustor. This reduces the amount of fuel consumed during power generation. The fuel heat rate for the hybrid cycle is 2660 Btu/kWh as compared to approximately 4000 Btu/kWh for a conventional CAES plant. A virtual stand-off between the hybrid plant and a conventional CAES plant at 235 mills/kWh in 1990 dollars is shown. With a lower cost and increased fuel cost projections, the hybrid system operating cost is less than that for a conventional CAES plant.

  19. Technical assessment and economic study of compressed air energy storage in Japan

    NASA Astrophysics Data System (ADS)

    Uchiyama, Y.; Kadoyu, M.

    1990-05-01

    In order to clarify the technological feasibility of compressed air energy storage systems (CAES) in Japan, economical analyses and technical investigations of the storage systems were conducted. The definition of efficiency of CAES was made clear and CAES was compared with other energy storage technologies, then followings were elucidated: the efficiency of CAES was inferior to that of the superconducting magnetic energy so far, but was superior to that of the pumped hydro; and may be improved up to that of the superconducting magnetic energy by technological progress in future. Storage facility of compressed air can be constructed by the existed technique on hard rock caverns. As to soft rock caverns and seabed storage tanks, there are subjects to be developed. Hard rock CAES systems can compete on generating cost with the conventional pumped hydro and LNG combined cycle if the site conditions are acceptable, however in other systems, the technical developments to improve the economy are required. Since the increasing ratio of the construction cost of CAES is lower in comparison with the pumped hydro which the construction cost increases with the site conditions, CAES is an expectative system as substitute for the pumped hydro.

  20. Assessment of gas compression and lung volume during air stacking maneuver.

    PubMed

    Sarmento, A; Resqueti, V R; Fregonezi, G A F; Aliverti, A

    2017-01-01

    We reasoned that the application of positive pressure through air stacking (AS) technique could cause gas compression and the absolute lung volumes could be estimated. The aim of this study was to estimate the amount of gas compression (ΔV comp) during AS in healthy subjects positioned at 45° trunk inclination and verify if the simultaneous measurements of chest wall volume changes (ΔV CW), by optoelectronic plethysmography, and changes in lung volume (ΔV ao), by pneumotachograph, combined with pressure variation at the airways opening (ΔP ao) during AS are able to provide reliable data on absolute lung volumes. Twenty healthy subjects (mean age 23.5 ± 3.8 years) were studied during a protocol that included slow vital capacity and AS maneuvers. V comp was calculated by subtracting ΔV ao and ΔV CW occurring during AS and total lung capacity (TLC) was estimated by applying Boyle-Mariote's law using V comp and ΔP ao. During AS, 0.140 ± 0.050 L of gas was compressed with an average ΔP ao of 21.78 ± 6.18 cmH2O. No significant differences between the estimated TLC (-0.03 ± 3.0% difference, p = 0.6020), estimated FRC (-2.0 ± 12.4% difference, p = 0.5172), measured IC (1.2 ± 11.2% difference, p = 0.7627) and predicted values were found. During AS, a significant gas compression occurs and absolute lung volumes can be estimated by simultaneous measurements of ΔV CW, ΔV ao and ΔP ao.

  1. Technical and economic assessment of fluidized-bed-augmented compressed air energy-storage system. Volume 3: Preconceptual design

    NASA Astrophysics Data System (ADS)

    Giramonti, A. J.; Lessard, R. D.; Merrick, D.; Hobson, M. J.

    1981-09-01

    A technical and economic assessment of fluidized bed combustion augmented compressed effort are presented in three volumes. Volume III - Preconceptual Design contains the system analysis which led to the identification of a preferred component configuration for a fluidized bed combustion augmented compressed air energy storage system, the results of the effort which transformed the preferred configuration into preconceptual power plant design, and an introductory evaluation of the performance of the power plant system during part-load operation and while load following.

  2. Thermo-fluidal behavior of the air in a cavern for the CAES-G/T[Compressed Air Energy Storage Gas Turbine

    SciTech Connect

    Tada, Shigeru; Yoshida, Hideo; Echigo, Ryozo; Oishi, Yasushi

    1999-07-01

    In this paper, a numerical analysis was performed to gain the detailed features of the thermo-fluidal behavior of the air inside the cavern for the compressed air storage gas turbine (CAES-G/T). The CAES-G/T, a peak shave power plant is now on the installation in Japan, where energy is stored in off peak period by compressed air in an underground cavern at pressure up to 80 atm abs. In the present work, an analytical model based on the two-dimensional laminar flow on the cross-section of the circular cavern was developed to quantify the effect of the transient process occurring in the cavern and wall during injection, storage and release of compressed air in the experimental circular cavern. the air was introduced until the required pressure inside the cavern is reached, then it was released outside after the storage period. It was found that the stratified temperature distribution was maintained in the cavern during compression and expansion periods. The wall temperature varied together with the variation of the air temperature with time, leading to the heat storage in the wall.

  3. Preliminary formation analysis for compressed air energy storage in depleted natural gas reservoirs :

    SciTech Connect

    Gardner, William Payton

    2013-06-01

    The purpose of this study is to develop an engineering and operational understanding of CAES performance for a depleted natural gas reservoir by evaluation of relative permeability effects of air, water and natural gas in depleted natural gas reservoirs as a reservoir is initially depleted, an air bubble is created, and as air is initially cycled. The composition of produced gases will be evaluated as the three phase flow of methane, nitrogen and brine are modeled. The effects of a methane gas phase on the relative permeability of air in a formation are investigated and the composition of the produced fluid, which consists primarily of the amount of natural gas in the produced air are determined. Simulations of compressed air energy storage (CAES) in depleted natural gas reservoirs were carried out to assess the effect of formation permeability on the design of a simple CAES system. The injection of N2 (as a proxy to air), and the extraction of the resulting gas mixture in a depleted natural gas reservoir were modeled using the TOUGH2 reservoir simulator with the EOS7c equation of state. The optimal borehole spacing was determined as a function of the formation scale intrinsic permeability. Natural gas reservoir results are similar to those for an aquifer. Borehole spacing is dependent upon the intrinsic permeability of the formation. Higher permeability allows increased injection and extraction rates which is equivalent to more power per borehole for a given screen length. The number of boreholes per 100 MW for a given intrinsic permeability in a depleted natural gas reservoir is essentially identical to that determined for a simple aquifer of identical properties. During bubble formation methane is displaced and a sharp N2methane boundary is formed with an almost pure N2 gas phase in the bubble near the borehole. During cycling mixing of methane and air occurs along the boundary as the air bubble boundary moves. The extracted gas mixture changes as a

  4. Modeling breathing-zone concentrations of airborne contaminants generated during compressed air spray painting.

    PubMed

    Flynn, M R; Gatano, B L; McKernan, J L; Dunn, K H; Blazicko, B A; Carlton, G N

    1999-01-01

    This paper presents a mathematical model to predict breathing-zone concentrations of airborne contaminants generated during compressed air spray painting in cross-flow ventilated booths. The model focuses on characterizing the generation and transport of overspray mist. It extends previous work on conventional spray guns to include exposures generated by HVLP guns. Dimensional analysis and scale model wind-tunnel studies are employed using non-volatile oils, instead of paint, to produce empirical equations for estimating exposure to total mass. Results indicate that a dimensionless breathing zone concentration is a nonlinear function of the ratio of momentum flux of air from the spray gun to the momentum flux of air passing through the projected area of the worker's body. The orientation of the spraying operation within the booth is also very significant. The exposure model requires an estimate of the contaminant generation rate, which is approximated by a simple impactor model. The results represent an initial step in the construction of more realistic models capable of predicting exposure as a mathematical function of the governing parameters.

  5. Roles of nitrogen, oxygen, and carbon dioxide in compressed-air narcosis.

    PubMed

    Hesser, C M; Fagraeus, L; Adolfson, J

    1978-12-01

    In an attempt to determine the roles of nitrogen, oxygen, and carbon dioxide in compressed-air narcosis, the effects on performance (mental function and manual dexterity) of adding CO2 in various concentrations to the inspired gas under three different conditions were studied in eight healthy male volunteers. The three conditions were: (1) air breathing at 1.3 ATA; (2) oxygen breathing at 1.7 ATA; and (3) air breathing at 8.0 ATA (same inspired O2 pressure as in (2)). By relating performance to the changes induced in end-tidal (alveolar) gas pressures, and comparing the data from the three conditions, we arrived at the following results and conclusions. A rise in O2 pressure to 1.65 ATA, or in N2 pressure to 6.3 ATA at a constant high PO2 level, caused a significant decrement of 10% in mental function but no consistent effect on psychomotor function. A rise in end-tidal PCO2 of 10 mmHg caused an impairment of approximately 10% in both mental and psychomotor functions. The results suggest that, at raised partial pressures, all three gases have narcotic properties, and that the mechanism of CO2 narcosis differs fundamentally from that of N2 and O2 narcosis.

  6. Knee-length graduated compression stockings for thromboprophylaxis in air travellers: A meta-analysis

    PubMed Central

    Sajid, Muhammad Shafique; Desai, Mittal; Morris, Richard; Hamilton, George

    2008-01-01

    OBJECTIVE: To systematically review the randomized controlled trials that have evaluated the efficacy of knee-length (KL) compression stockings for thromboprophylaxis in air travellers. METHOD: After an electronic database search, the randomized controlled trials that studied passengers on long-haul flights were selected and analyzed to generate summative data. RESULTS: Nine trials studying participants using KL stockings were analyzed. Forty-six of 1261 participants randomly assigned to the control group developed deep vein thrombosis (DVT), compared with two of 1237 participants (0.16%) in the KL stockings group. The weighted risk difference was −0.034, which indicated that the absolute difference was 3.4% in the incidence of DVT, in favour of KL stockings. The number needed to treat with KL stockings to avoid one case of DVT was 29.4. However, there was significant heterogeneity among trials. The RR for DVT was 0.08 in high-risk participants and 0.14 in low- to medium-risk participants. CONCLUSION: KL stockings are effective for thromboprophylaxis in air travellers at low, medium and high risk of DVT. The use of KL stockings should form an important part of air traveller education on lowering the burden of DVT. The results of the present meta-analysis can be used to advise travellers on their risk of DVT and preventive strategies. PMID:22477413

  7. Technical and economic assessment of fluidized bed augmented compressed air energy storage system. Volume III. Preconceptual design

    SciTech Connect

    Giramonti, A.J.; Lessard, R.D.; Merrick, D.; Hobson, M.J.

    1981-09-01

    A technical and economic assessment of fluidized bed combustion augmented compressed air energy storage systems is presented. The results of this assessment effort are presented in three volumes. Volume III - Preconceptual Design contains the system analysis which led to the identification of a preferred component configuration for a fluidized bed combustion augmented compressed air energy storage system, the results of the effort which transformed the preferred configuration into preconceptual power plant design, and an introductory evaluation of the performance of the power plant system during part-load operation and while load following.

  8. American Water Heater Company: Compressed Air System Optimization Project Saves Energy and Improves Production at Water Heater Plant

    SciTech Connect

    2003-11-01

    In 2001, American Water Heater Company implemented a system-level improvement project on the compressed air system that serves its manufacturing plant in Johnson City, Tennessee. The plant now operates with less compressor capacity, which has reduced its energy consumption and maintenance needs. The project's total cost was $228,000. The annual compressed air energy savings (2,345,000 kWh) and maintenance savings total $160,000, yielding a simple payback of 17 months. Furthermore, the system now supports the plant's production processes more effectively, which has improved product quality and increased production.

  9. Modeling of coupled thermodynamic and geomechanical performance of underground compressed air energy storage in lined rock caverns

    SciTech Connect

    Rutqvist, Jonny; Kim, Hyung-Mok; Ryu, Dong-Woo; Synn, Joong-Ho; Song, Won-Kyong

    2012-06-01

    We applied coupled nonisothermal, multiphase fluid flow and geomechanical numerical modeling to study the coupled thermodynamic and geomechanical performance of underground compressed air energy storage (CAES) in concrete-lined rock caverns. The paper focuses on CAES in lined caverns at relatively shallow depth (e.g., 100 m depth) in which a typical CAES operational pressure of 5 to 8 MPa is significantly higher than both ambient fluid pressure and in situ stress. We simulated a storage operation that included cyclic compression and decompression of air in the cavern, and investigated how pressure, temperature and stress evolve over several months of operation. We analyzed two different lining options, both with a 50 cm thick low permeability concrete lining, but in one case with an internal synthetic seal such as steel or rubber. For our simulated CAES system, the thermodynamic analysis showed that 96.7% of the energy injected during compression could be recovered during subsequent decompression, while 3.3% of the energy was lost by heat conduction to the surrounding media. Our geomechanical analysis showed that tensile effective stresses as high as 8 MPa could develop in the lining as a result of the air pressure exerted on the inner surface of the lining, whereas thermal stresses were relatively smaller and compressive. With the option of an internal synthetic seal, the maximum effective tensile stress was reduced from 8 to 5 MPa, but was still in substantial tension. We performed one simulation in which the tensile tangential stresses resulted in radial cracks and air leakage though the lining. This air leakage, however, was minor (about 0.16% of the air mass loss from one daily compression) in terms of CAES operational efficiency, and did not significantly impact the overall energy balance of the system. However, despite being minor in terms of energy balance, the air leakage resulted in a distinct pressure increase in the surrounding rock that could be

  10. Advanced concepts: The second generation of compressed air-energy storage technology

    NASA Astrophysics Data System (ADS)

    Kannberg, L. D.

    1981-09-01

    A description and assessment is provided for four second generation compressed air energy storage (CAES) concepts; abiabatic CAES, hybrid CAES, CAES with coal gasification (CG), and CAES with pressurized fluidized bed combustion (PFBC). These are based on information provided in conceptual design studies performed by Acres American, Inc., United Engineers and Constructors, and United Technologies Research Center. The assessment covers consideration of the technological readiness, relative economic benefits and operational viability of each concept. It was concluded that the adiabatic CAES concept appears to be the most attractive candidate for utility application in the near future. It is operationally viable, economically attractive compared with competing concepts, and will require relatively little additional development before commercialization. It was estimated that a utility could start the design of a commercial plant in 2 to 3 years if research regarding TES system design is undertaken in a timely manner.

  11. Compressed air energy storage system reservoir size for a wind energy baseload power plant

    SciTech Connect

    Cavallo, A.J.

    1996-12-31

    Wind generated electricity can be transformed from an intermittent to a baseload resource using an oversized wind farm in conjunction with a compressed air energy storage (CAES) system. The size of the storage reservoir for the CAES system (solution mined salt cavern or porous media) as a function of the wind speed autocorrelation time (C) has been examined using a Monte Carlo simulation for a wind class 4 (wind power density 450 W m{sup -2} at 50 m hub height) wind regime with a Weibull k factor of 2.5. For values of C typically found for winds over the US Great Plains, the storage reservoir must have a 60 to 80 hour capacity. Since underground reservoirs account for only a small fraction of total system cost, this larger storage reservoir has a negligible effect on the cost of energy from the wind energy baseload system. 7 refs., 2 figs., 1 tab.

  12. Technology assessment report for the Soyland Power Cooperative, Inc. compressed air energy storage system (CAES)

    NASA Astrophysics Data System (ADS)

    1982-01-01

    The design and operational features of compressed air energy storage systems (CAES) in general and, specifically, of a proposed 220 MW plant being planned by the Soyland Power Cooperative, Inc., in Illinois are described. The need for peaking capacity, CAES requirements for land, fuel, water, and storage caverns, are discussed, and the costs, environmental impacts and licensing requirements of CAES are compared with those of power plants using simple cycle or combined cycle combustion turbines. It is concluded that during the initial two years of CAES operation, the CAES would cost more than a combustion turbine or combined cycle facility, but thereafter the CAES would have a increasing economic advantage. The overall environmental impact of a CAES plant is minimal, and there should be no great difficulties with CAES licensing.

  13. Clean air program: Compressed natural gas safety in transit operations. Final report

    SciTech Connect

    Friedman, D.M.; Malcosky, N.D.

    1995-10-01

    This report examines the safety issues relating to the use of Compressed Natural Gas (CNG) in transit service. The safety issues were determined by on-site surveys performed by Battelle of Columbus, Ohio and Science Applications International Corporation (SAIC) of McLean, Virginia of seven transit agencies using CNG. The survey consisted of: (1) extensive interviews; (2) review of records, procedures, and plans relating to safety; (3) examination of facilities and equipment; (4) observation of operations including fueling, maintenance, morning start-up, and revenue service; and (5) measurements of methane concentrations in the air where the buses are being fueled or stored. Interviews included all job categories associated with management, operations, safety, maintenance, acquisition, and support.

  14. A new software for planning the compressed air networks in mines

    SciTech Connect

    Madani, H.; Asadi, A.

    1996-12-31

    There are different formulae for calculation of pressure loss in compressed air networks, but all have some limitation (length, diameter, flowrate temperature ... ). In practice, it is not easy to evaluate these formulae and choose the most suitable one for each case. In order to overcome these difficulties, a computer program was written in the form of an M.Sc thesis, and the result is a new software which can be used for calculation of pressure loss and choosing the optimum diameter of the pipes. After entering data, computer chooses the best formula (out of 14) for each branch of the network, based on the condition, and the result is available with different confidential limits.

  15. Compressed air demand-type firefighter's breathing system, volume 1. [design analysis and performance tests

    NASA Technical Reports Server (NTRS)

    Sullivan, J. L.

    1975-01-01

    The commercial availability of lightweight high pressure compressed air vessels has resulted in a lightweight firefighter's breathing apparatus. The improved apparatus, and details of its design and development are described. The apparatus includes a compact harness assembly, a backplate mounted pressure reducer assembly, a lightweight bubble-type facemask with a mask mounted demand breathing regulator. Incorporated in the breathing regulator is exhalation valve, a purge valve and a whistle-type low pressure warning that sounds only during inhalation. The pressure reducer assembly includes two pressure reducers, an automatic transfer valve and a signaling device for the low pressure warning. Twenty systems were fabricated, tested, refined through an alternating development and test sequence, and extensively examined in a field evaluation program. Photographs of the apparatus are included.

  16. Combined compressed air storage-low BTU coal gasification power plant

    DOEpatents

    Kartsounes, George T.; Sather, Norman F.

    1979-01-01

    An electrical generating power plant includes a Compressed Air Energy Storage System (CAES) fueled with low BTU coal gas generated in a continuously operating high pressure coal gasifier system. This system is used in coordination with a continuously operating main power generating plant to store excess power generated during off-peak hours from the power generating plant, and to return the stored energy as peak power to the power generating plant when needed. The excess coal gas which is produced by the coal gasifier during off-peak hours is stored in a coal gas reservoir. During peak hours the stored coal gas is combined with the output of the coal gasifier to fuel the gas turbines and ultimately supply electrical power to the base power plant.

  17. Slow Dynamics Model of Compressed Air Energy Storage and Battery Storage Technologies for Automatic Generation Control

    SciTech Connect

    Krishnan, Venkat; Das, Trishna

    2016-05-01

    Increasing variable generation penetration and the consequent increase in short-term variability makes energy storage technologies look attractive, especially in the ancillary market for providing frequency regulation services. This paper presents slow dynamics model for compressed air energy storage and battery storage technologies that can be used in automatic generation control studies to assess the system frequency response and quantify the benefits from storage technologies in providing regulation service. The paper also represents the slow dynamics model of the power system integrated with storage technologies in a complete state space form. The storage technologies have been integrated to the IEEE 24 bus system with single area, and a comparative study of various solution strategies including transmission enhancement and combustion turbine have been performed in terms of generation cycling and frequency response performance metrics.

  18. A Feasibility Study on Operating Large Scale Compressed Air Energy Storage in Porous Formations

    NASA Astrophysics Data System (ADS)

    Wang, B.; Pfeiffer, W. T.; Li, D.; Bauer, S.

    2015-12-01

    Compressed air energy storage (CAES) in porous formations has been considered as one promising option of large scale energy storage for decades. This study, hereby, aims at analyzing the feasibility of operating large scale CAES in porous formations and evaluating the performance of underground porous gas reservoirs. To address these issues quantitatively, a hypothetic CAES scenario with a typical anticline structure in northern Germany was numerically simulated. Because of the rapid growth in photovoltaics, the period of extraction in a daily cycle was set to the early morning and the late afternoon in order to bypass the massive solar energy production around noon. The gas turbine scenario was defined referring to the specifications of the Huntorf CAES power plant. The numerical simulations involved two stages, i.e. initial fill and cyclic operation, and both were carried out using the Eclipse E300 simulator (Schlumberger). Pressure loss in the gas wells was post analyzed using an analytical solution. The exergy concept was applied to evaluate the potential energy amount stored in the specific porous formation. The simulation results show that porous formations prove to be a feasible solution of large scale CAES. The initial fill with shut-in periods determines the spatial distribution of the gas phase and helps to achieve higher gas saturation around the wells, and thus higher deliverability. The performance evaluation shows that the overall exergy flow of stored compressed air is also determined by the permeability, which directly affects the deliverability of the gas reservoir and thus the number of wells required.

  19. The use of broadband acoustic transducers and pulse-compression techniques for air-coupled ultrasonic imaging.

    PubMed

    Gan, T H; Hutchins, D A; Billson, D R; Schindel, D W

    2001-04-01

    A pulse-compression technique has been applied to air-coupled testing of solid materials. Capacitance transducers were used to generate wide bandwidth swept-frequency (chirp) signals in air, which were then used to measure and image solid samples in through transmission. The results demonstrate that such signal processing techniques lead to an improvement in the signal to noise ratio and timing accuracy for air-coupled testing. Measurements of thickness and spectroscopic experiments are presented. Images of defects in a wide range of materials, including metals and carbon-fibre composites have also been obtained. This combination of capacitive transducers with pulse-compression techniques is shown to be a powerful tool for non-contact air-coupled ultrasonic measurements.

  20. Feasibility study of porous media compressed air energy storage in South Carolina, United States of America

    NASA Astrophysics Data System (ADS)

    Jarvis, Alexandra-Selene

    Renewable Energy Systems (RES) such as solar and wind, are expected to play a progressively significant role in electricity production as the world begins to move away from an almost total reliance on nonrenewable sources of power. In the US there is increasing investment in RES as the Department of Energy (DOE) expands its wind power network to encompass the use of offshore wind resources in places such as the South Carolina (SC) Atlantic Coastal Plain. Because of their unstable nature, RES cannot be used as reliable grid-scale power sources unless power is somehow stored during excess production and recovered at times of insufficiency. Only two technologies have been cited as capable of storing renewable energy at this scale: Pumped Hydro Storage and Compressed Air Energy Storage (CAES). Both CAES power plants in existence today use solution-mined caverns as their storage spaces. This project focuses on exploring the feasibility of employing the CAES method to store excess wind energy in sand aquifers. The numerical multiphase flow code, TOUGH2, was used to build models that approximate subsurface sand formations similar to those found in SC. Although the aquifers of SC have very low dips, less than 10, the aquifers in this study were modeled as flat, or having dips of 00. Cycle efficiency is defined here as the amount of energy recovered compared to the amount of energy injected. Both 2D and 3D simulations have shown that the greatest control on cycle efficiency is the volume of air that can be recovered from the aquifer after injection. Results from 2D simulations showed that using a dual daily peak load schedule instead of a single daily peak load schedule increased cycle efficiency as do the following parameters: increased anisotropy, screening the well in the upper portions of the aquifer, reduced aquifer thickness, and an initial water displacement by the continuous injection of air for at least 60 days. Aquifer permeability of 1x10-12 m2 produced a cycle

  1. Tension-Compression Fatigue of an Oxide/Oxide Ceramic Matrix Composite at Elevated Temperature in Air and Steam Environments

    DTIC Science & Technology

    2015-03-26

    Gszczuk LB. Microbuckling Failure of Circular Fiber-Reinforced Composites . AIAA J 1975; 13:1311-18. [53] Wang ASD. A Non-Linear Microbuckling Model...TENSION-COMPRESSION FATIGUE OF AN OXIDE/OXIDE CERAMIC MATRIX COMPOSITE AT ELEVATED TEMPERATURE IN... COMPOSITE AT ELEVATED TEMPERATURE IN AIR AND STEAM ENVIRONMENTS THESIS Presented to the Faculty Department of Aeronautics and Astronautics

  2. Effects of radiation and compression on propagating spherical flames of methane/air mixtures near the lean flammability limit

    SciTech Connect

    Chen, Zheng

    2010-12-15

    Large discrepancies between the laminar flame speeds and Markstein lengths measured in experiments and those predicted by simulations for ultra-lean methane/air mixtures bring a great concern for kinetic mechanism validation. In order to quantitatively explain these discrepancies, a computational study is performed for propagating spherical flames of lean methane/air mixtures in different spherical chambers using different radiation models. The emphasis is focused on the effects of radiation and compression. It is found that the spherical flame propagation speed is greatly reduced by the coupling between thermal effect (change of flame temperature or unburned gas temperature) and flow effect (inward flow of burned gas) induced by radiation and/or compression. As a result, for methane/air mixtures near the lean flammability limit, the radiation and compression cause large amounts of under-prediction of the laminar flame speeds and Markstein lengths extracted from propagating spherical flames. Since radiation and compression both exist in the experiments on ultra-lean methane/air mixtures reported in the literature, the measured laminar flame speeds and Markstein lengths are much lower than results from simulation and thus cannot be used for kinetic mechanism validation. (author)

  3. Evaluation of hard-rock-cavern construction methods for compressed-air energy storage: Final report

    SciTech Connect

    Thrasher, J.E.; Lange, R.B.

    1988-04-01

    This report presents the results of construction cost and schedule estimates for caverns mined in hard rock for 100-MW and 220-MW compressed air energy storage (CAES) plants with 10 hours storage capacity and using either water-compensated cavern operation with constant turbine-inlet pressure operation on uncompensated cavern operation with sliding turbine-inlet pressure operation. The estimates are made for caverns mined by large-parallel-tunnel methods and by room-and-pillar methods. The results indicate that, for the cavern sizes involved, the room-and-pillar method is cost-competitive with the large-parallel-tunnel methods, but the method requires marginally more construction time. The largest cavern size in the estimates may, however, be approaching the size where the room-and-pillar method may no longer be competitive. The technical feasibility of water curtains for preventing or minimizing leakage of air from CAES hard-rock caverns is evaluated, and construction cost and schedule estimates are made for uncompensated caverns. It is concluded that the performance of water curtains is dependent upon the accuracy of the values of site specific variables and assumptions utilized in the design. A method is presented for assessing if a water curtain may be economical for a compensated CAES cavern. Such an assessment for a water curtain for an uncompensated CAES cavern is more complex and beyond the scope of this study. Also, a program for testing the operation of a water curtain in conjunction with an air-storage cavern operation is proposed. For the specific cavern sizes considered in this report, the estimated water-curtain construction costs and times for the uncompensated room-and-pillar caverns are found to be greater than for the uncompensated large-parallel-tunnel caverns. 11 refs., 18 figs., 19 tabs.

  4. Influence of extensive compressed natural gas (CNG) usage on air quality

    NASA Astrophysics Data System (ADS)

    Suthawaree, Jeeranut; Sikder, Helena Akhter; Jones, Charlotte Emily; Kato, Shungo; Kunimi, Hitoshi; Mohammed Hamidul Kabir, Abu Naser; Kajii, Yoshizumi

    2012-07-01

    Compressed Natural Gas (CNG) is an inexpensive, indigenous energy resource which currently accounts for the majority of automobile and domestic energy consumption in Bangladesh. This extensive CNG usage, particularly within the capital city, Dhaka, heavily influences the atmospheric composition (and hence air quality), yet to date measurements of trace gases in regions dominated by CNG emissions are relatively limited. Here we report continuous observations of the atmospherically important trace gases O3, CO, SO2, NOx and volatile organic compounds (VOC), in ambient air in Dhaka City, Bangladesh, during May 2011. The average mixing ratios of O3, CO, SO2, and NOx for the measurement period were 18.9, 520.9, 7.6 and 21.5 ppbv, respectively. The ratios of CO to NO reveal that emissions from gasoline and CNG-fuelled vehicles were dominant during the daytime (slope of ˜26), while in contrast, owing to restrictions imposed on diesel fuelled vehicles entering Dhaka City, emissions from these vehicles only became significant during the night (slope of ˜10). The total VOC mixing ratio in Dhaka was ˜5-10 times higher than the levels reported in more developed Asian cities such as Tokyo and Bangkok, which consequently gives rise to a higher ozone formation potential (OFP). However, the most abundant VOC in Dhaka were the relatively long-lived ethane and propane (with mean mixing ratios of ˜115 and ˜30 ppbv, respectively), and as a consequence, the ozone formation potential per ppb carbon (ppbC) was lower in Dhaka than in Tokyo and Bangkok. Thus the atmospheric composition of air influenced by extensive CNG combustion may be characterized by high VOC mixing ratios, yet mixing ratios of the photochemical pollutant ozone do not drastically exceed the levels typical of Asian cities with considerably lower VOC levels.

  5. Estimation of air void and aggregate spatial distributions in concrete under uniaxial compression using computer tomography scanning

    SciTech Connect

    Wong, R.C.K. . E-mail: rckwong@ucalgary.ca; Chau, K.T.

    2005-08-01

    Normal- and high-strength concrete cylinders (designed compressive strengths of 30 and 90 MPa at 28 days) were loaded uniaxially. Computer tomography (CT) scanning technique was used to examine the evolution of air voids inside the specimens at various loading states up to 85% of the ultimate compressive strength. The normal-strength concrete yielded a very different behaviour in changes of internal microstructure as compared to the high-strength concrete. There were significant instances of nucleation and growth in air voids in the normal-strength concrete specimen, while the increase in air voids in the high-strength concrete specimen was insignificant. In addition, CT images were used for mapping the aggregate spatial distributions within the specimens. No intrinsic anisotropy was detected from the fabric analysis.

  6. Geochemical effects of compressed air, methane, or hydrogen intrusion into shallow aquifers

    NASA Astrophysics Data System (ADS)

    Berta, Marton; Dethlefsen, Frank; Ebert, Markus; Dahmke, Andreas

    2016-04-01

    The fluctuating energy yield of renewable sources, most importantly wind and solar, implies the emerging necessity of energy storage. Already operating possibilities for geological energy storage include storage of compressed air (CAES), methane, and hydrogen. For the safe and sustainable implementation of subsurface energy storage, site specific risk assessment studies and elaborated monitoring strategies are needed, based on proper process understanding. In case of gas storage, this process understanding must include gas-specific reactions to be expected in shallow aquifers following a leakage of compressed air, methane, or hydrogen, and therefore potentially changing the composition of the groundwater, which is protected by law. As the geochemical reactions potentially following gas leakages were not known in a sufficient extent, experiments representing relevant hydrogeological conditions were carried out. The experimental approach included batch and column experiments using mainly sediment from a shallow Pleistocene aquifer percolated by the groundwater from the same aquifer. This water was saturated with the respective gas to simulate a leakage environment in a shallow aquifer. Leakage of compressed air resulted in pyrite oxidation (rates up to 4 μM/h). In our experimental conditions with oxygen partial pressures between 0 and 11 bars pyrite oxidation caused minor (up to 0.5 mM) increase in sulfate concentration and minor (up to 0.5) decrease in pH. The transfer function on reaction kinetics developed using PHREEQC based on the experimental reaction rates for upscaling the results includes a passivation inhibiting more than 90% of the pyrite reactivity. Methane oxidation coupled to reduction of nitrate, and especially sulfate is known from various groundwater and marine environments. However, fugitive methane does not cause detectable changes in groundwater within one year in our experiments. This acknowledges earlier field studies describing no methane

  7. Compressed Speech: Potential Application for Air Force Technical Training. Final Report, August 73-November 73.

    ERIC Educational Resources Information Center

    Dailey, K. Anne

    Time-compressed speech (also called compressed speech, speeded speech, or accelerated speech) is an extension of the normal recording procedure for reproducing the spoken word. Compressed speech can be used to achieve dramatic reductions in listening time without significant loss in comprehension. The implications of such temporal reductions in…

  8. Compressed Speech: Potential Application for Air Force Technical Training. Final Report, August 73-November 73.

    ERIC Educational Resources Information Center

    Dailey, K. Anne

    Time-compressed speech (also called compressed speech, speeded speech, or accelerated speech) is an extension of the normal recording procedure for reproducing the spoken word. Compressed speech can be used to achieve dramatic reductions in listening time without significant loss in comprehension. The implications of such temporal reductions in…

  9. Conceptual design and engineering studies of adiabatic compressed air energy storage (CAES) with thermal energy storage

    SciTech Connect

    Hobson, M. J.

    1981-11-01

    The objective of this study was to perform a conceptual engineering design and evaluation study and to develop a design for an adiabatic CAES system using water-compensated hard rock caverns for compressed air storage. The conceptual plant design was to feature underground containment for thermal energy storage and water-compensated hard rock caverns for high pressure air storage. Other design constraints included the selection of turbomachinery designs that would require little development and would therefore be available for near-term plant construction and demonstration. The design was to be based upon the DOE/EPRI/PEPCO-funded 231 MW/unit conventional CAES plant design prepared for a site in Maryland. This report summarizes the project, its findings, and the recommendations of the study team; presents the development and optimization of the plant heat cycle and the selection and thermal design of the thermal energy storage system; discusses the selection of turbomachinery and estimated plant performance and operational capability; describes the control system concept; and presents the conceptual design of the adiabatic CAES plant, the cost estimates and economic evaluation, and an assessment of technical and economic feasibility. Particular areas in the plant design requiring further development or investigation are discussed. It is concluded that the adiabatic concept appears to be the most attractive candidate for utility application in the near future. It is operationally viable, economically attractive compared with competing concerns, and will require relatively little development before the construction of a plant can be undertaken. It is estimated that a utility could start the design of a demonstration plant in 2 to 3 years if research regarding TES system design is undertaken in a timely manner. (LCL)

  10. Exploring the concept of compressed air energy storage (CAES) in lined rock caverns at shallow depth: A modeling study of air tightness and energy balance

    SciTech Connect

    Kim, H.-M.; Rutqvist, J.; Ryu, D.-W.; Choi, B.-H.; Sunwoo, C.; Song, W.-K.

    2011-07-15

    This paper presents a numerical modeling study of coupled thermodynamic, multiphase fluid flow and heat transport associated with underground compressed air energy storage (CAES) in lined rock caverns. Specifically, we explored the concept of using concrete lined caverns at a relatively shallow depth for which constructing and operational costs may be reduced if air tightness and stability can be assured. Our analysis showed that the key parameter to assure long-term air tightness in such a system was the permeability of both the concrete lining and the surrounding rock. The analysis also indicated that a concrete lining with a permeability of less than 1×10{sup -18} m{sup 2} would result in an acceptable air leakage rate of less than 1%, with the operational pressure range between 5 and 8 MPa at a depth of 100 m. It was further noted that capillary retention properties and the initial liquid saturation of the lining were very important. Indeed, air leakage could be effectively prevented when the air-entry pressure of the concrete lining is higher than the operational air pressure and when the lining is kept moist at a relatively high liquid saturation. Our subsequent energy-balance analysis demonstrated that the energy loss for a daily compression and decompression cycle is governed by the air-pressure loss, as well as heat loss by conduction to the concrete liner and surrounding rock. For a sufficiently tight system, i.e., for a concrete permeability off less than 1×10{sup -18} m{sup 2}, heat loss by heat conduction tends to become proportionally more important. However, the energy loss by heat conduction can be minimized by keeping the air-injection temperature of compressed air closer to the ambient temperature of the underground storage cavern. In such a case, almost all the heat loss during compression is gained back during subsequent decompression. Finally, our numerical simulation study showed that CAES in shallow rock caverns is feasible from a leakage

  11. The value of compressed air energy storage in energy and reserve markets

    DOE PAGES

    Drury, Easan; Denholm, Paul; Sioshansi, Ramteen

    2011-06-28

    Storage devices can provide several grid services, however it is challenging to quantify the value of providing several services and to optimally allocate storage resources to maximize value. We develop a co-optimized Compressed Air Energy Storage (CAES) dispatch model to characterize the value of providing operating reserves in addition to energy arbitrage in several U.S. markets. We use the model to: (1) quantify the added value of providing operating reserves in addition to energy arbitrage; (2) evaluate the dynamic nature of optimally allocating storage resources into energy and reserve markets; and (3) quantify the sensitivity of CAES net revenues tomore » several design and performance parameters. We find that conventional CAES systems could earn an additional 23 ± 10/kW-yr by providing operating reserves, and adiabatic CAES systems could earn an additional 28 ± 13/kW-yr. We find that arbitrage-only revenues are unlikely to support a CAES investment in most market locations, but the addition of reserve revenues could support a conventional CAES investment in several markets. Adiabatic CAES revenues are not likely to support an investment in most regions studied. As a result, modifying CAES design and performance parameters primarily impacts arbitrage revenues, and optimizing CAES design will be nearly independent of dispatch strategy.« less

  12. Compressed air energy storage monitoring to support refrigerated mined rock cavern technology.

    SciTech Connect

    Lee, Moo Yul; Bauer, Stephen J.

    2004-06-01

    This document is the final report for the Compressed Air Energy Storage Monitoring to Support Refrigerated-Mined Rock Cavern Technology (CAES Monitoring to Support RMRCT) (DE-FC26-01NT40868) project to have been conducted by CAES Development Co., along with Sandia National Laboratories. This document provides a final report covering tasks 1.0 and subtasks 2.1, 2.2, and 2.5 of task 2.0 of the Statement of Project Objectives and constitutes the final project deliverable. The proposed work was to have provided physical measurements and analyses of large-scale rock mass response to pressure cycling. The goal was to develop proof-of-concept data for a previously developed and DOE sponsored technology (RMRCT or Refrigerated-Mined Rock Cavern Technology). In the RMRCT concept, a room and pillar mine developed in rock serves as a pressure vessel. That vessel will need to contain pressure of about 1370 psi (and cycle down to 300 psi). The measurements gathered in this study would have provided a means to determine directly rock mass response during cyclic loading on the same scale, under similar pressure conditions. The CAES project has been delayed due to national economic unrest in the energy sector.

  13. The value of compressed air energy storage in energy and reserve markets

    SciTech Connect

    Drury, Easan; Denholm, Paul; Sioshansi, Ramteen

    2011-06-28

    Storage devices can provide several grid services, however it is challenging to quantify the value of providing several services and to optimally allocate storage resources to maximize value. We develop a co-optimized Compressed Air Energy Storage (CAES) dispatch model to characterize the value of providing operating reserves in addition to energy arbitrage in several U.S. markets. We use the model to: (1) quantify the added value of providing operating reserves in addition to energy arbitrage; (2) evaluate the dynamic nature of optimally allocating storage resources into energy and reserve markets; and (3) quantify the sensitivity of CAES net revenues to several design and performance parameters. We find that conventional CAES systems could earn an additional 23 ± 10/kW-yr by providing operating reserves, and adiabatic CAES systems could earn an additional 28 ± 13/kW-yr. We find that arbitrage-only revenues are unlikely to support a CAES investment in most market locations, but the addition of reserve revenues could support a conventional CAES investment in several markets. Adiabatic CAES revenues are not likely to support an investment in most regions studied. As a result, modifying CAES design and performance parameters primarily impacts arbitrage revenues, and optimizing CAES design will be nearly independent of dispatch strategy.

  14. The value of compressed air energy storage with wind in transmission-constrained electric power systems

    DOE PAGES

    Denholm, Paul; Sioshansi, Ramteen

    2009-05-05

    In this paper, we examine the potential advantages of co-locating wind and energy storage to increase transmission utilization and decrease transmission costs. Co-location of wind and storage decreases transmission requirements, but also decreases the economic value of energy storage compared to locating energy storage at the load. This represents a tradeoff which we examine to estimate the transmission costs required to justify moving storage from load-sited to wind-sited in three different locations in the United States. We examined compressed air energy storage (CAES) in three “wind by wire” scenarios with a variety of transmission and CAES sizes relative to amore » given amount of wind. In the sites and years evaluated, the optimal amount of transmission ranges from 60% to 100% of the wind farm rating, with the optimal amount of CAES equal to 0–35% of the wind farm rating, depending heavily on wind resource, value of electricity in the local market, and the cost of natural gas.« less

  15. The value of compressed air energy storage with wind in transmission-constrained electric power systems

    SciTech Connect

    Denholm, Paul; Sioshansi, Ramteen

    2009-05-05

    In this paper, we examine the potential advantages of co-locating wind and energy storage to increase transmission utilization and decrease transmission costs. Co-location of wind and storage decreases transmission requirements, but also decreases the economic value of energy storage compared to locating energy storage at the load. This represents a tradeoff which we examine to estimate the transmission costs required to justify moving storage from load-sited to wind-sited in three different locations in the United States. We examined compressed air energy storage (CAES) in three “wind by wire” scenarios with a variety of transmission and CAES sizes relative to a given amount of wind. In the sites and years evaluated, the optimal amount of transmission ranges from 60% to 100% of the wind farm rating, with the optimal amount of CAES equal to 0–35% of the wind farm rating, depending heavily on wind resource, value of electricity in the local market, and the cost of natural gas.

  16. Review of environmental studies and issues on compressed-air energy storage

    SciTech Connect

    Not Available

    1983-03-01

    This report is a summary of the environmental and regulatory issues associated with Compressed Air Energy Storage (CAES) technology. It reviews from an environmental perspective the progress and results of extensive engineering research and technology development directed at commercial development of CAES technology. A comprehensive analysis of the legal and regulatory issues associated with CAES is also summarized. Significant conclusions are: the environmental impacts associated with construction and operation of CAES facilities are generally similar to or less severe than those associated with construction of conventional electrical generating facilities; adverse subsurface and surface environmental impacts can be largely avoided by thorough geological characterization of subsurface conditions, careful evaluation of surface environmental factors, and avoidance of unsuitable sites; the US has a large number of suitable sites; siting flexibility for CAES facilities is much greater than for other energy storage technologies; land use requirements are generally significantly less than for conventional generating facilities of similar genrating capacity; petroleum fuel use is much less than for conventional peak power generating facilities; CAES technology offers the potential for increased efficiency of utilization of utility system generating capacity which results in reduced overall resources commitment and reduced environmental impacts; and, due to lack of implementation experience, uncertainty still surrounds the legal and regulatory issues associated with CAES.

  17. Effect of focal size on the laser ignition of compressed natural gas-air mixture

    NASA Astrophysics Data System (ADS)

    Srivastava, Dhananjay Kumar; Wintner, Ernst; Agarwal, Avinash Kumar

    2014-07-01

    Laser ignition of compressed natural gas-air mixtures was investigated in a constant volume combustion chamber (CVCC) as well as in a single cylinder engine. Laser ignition has several potential advantages over conventional spark ignition system. Laser ignition relies on the fact that optical breakdown (plasma generation) in gases occurs at high intensities of ≈1011 W/cm2. Such high intensities can be achieved by focusing a pulsed laser beam to small focal sizes. The focal spot size depends on several parameters such as laser wavelength, beam diameter at the converging lens, beam quality and focal length. In this investigation, the focal length of the converging lens and the beam quality were varied and the corresponding effects on minimum ignition energy as well as pressure rise were recorded. The flame kernel was visualized and correlated with the rate of pressure rise inside the combustion chamber. This investigation will be helpful in the optimization of laser and optics parameters in laser ignition. It was found that beam quality factor and focal length of focusing lens have a strong impact on the minimum ignition energy required for combustion. Combustion duration depends on the energy density at the focal spot and size of the flame kernel.

  18. Experimental Results Obtained with Air Liquide Cold Compression System: CERN LHC and SNS Projects

    NASA Astrophysics Data System (ADS)

    Delcayre, F.; Courty, J.-C.; Hamber, F.; Hilbert, B.; Monneret, E.; Toia, J.-L.

    2006-04-01

    Large scale collider facilities will make intensive use of superconducting magnets, operating below 2.0 K. This dictates high-capacity refrigeration systems operating below 2.0 K. These systems, making use of cryogenic centrifugal compressors in a series arrangement with room temperature screw compressors will be coupled to a refrigerator, providing a certain power at 4.5 K. A first Air Liquide Cold Compression System (CCS) unit was built and delivered to CERN in 2001. Installed at the beginning of 2002, it was commissioned and tested successfully during year 2002. A series of four sets of identical CCS were then tested in 2004. Another set of four cryogenic centrifugal compressors (CCC) has been delivered to Thomas Jefferson National Accelerator Facility (JLAB) for the Spallation Neutron Source (SNS) in 2002. These compressors were tested and commissioned from December 2004 to July 2005. The experimental results obtained with these systems will be presented and discussed: the characteristics of the CCC will be detailed. The principles of control for the CCC in series will be detailed.

  19. Use of air stacking and abdominal compression for cough assistance in people with complete tetraplegia.

    PubMed

    Torres-Castro, R; Vilaró, J; Vera-Uribe, R; Monge, G; Avilés, P; Suranyi, C

    2014-05-01

    Cross-sectional. To assess cough using air stacking (AS) to assist inspiratory volume with abdominal compression (AC) during expiration in patients with American Spinal Injury Association Impairment Scale (AIS) A. Large tertiary hospital in Chile. Peak cough flow (PCF) was measured during four different interventions: spontaneous maximal expiratory effort (MEE); MEE while receiving AC (MEE-AC); MEE after AS with a manual resuscitation bag (AS-MEE); and MEE with AS and AC (AS-MEE-AC). Fifteen in-patients with complete tetraplegia (C4-C6) were included. Median age was 33 years (16-56). PCF during the different interventions was PCF for MEE was 183±90 l min(-1); PCF for MEE-AC was 273±119  l  min(-1); PCF for AS-MEE was 278±106  l  min(-1) and PCF for AS-MEE-AC was 368±129  l  min(-1). We observed significant differences in PCF while applying MEE-AC and AS-MEE compared with MEE (P=0.0001). However, the difference in PCF value was greater using the AS-MEE-AC technique (P=0.00001). Patients with spinal cord injury (SCI) presented an ineffective cough that constitutes a risk factor for developing respiratory complications. The application of combined techniques (AS-MEE-AC) can reach near normal PCF values. This is a low-cost, simple and easily applied intervention that could be introduced to all patients with tetraplegia.

  20. Compressed-air energy storage: Commercialization potential and EPRI roles in the commercialization process

    NASA Astrophysics Data System (ADS)

    Boyd, D. W.; Buckley, O. E.; Clark, C. E.

    1982-12-01

    This report describes an assessment of potential roles that EPRI might take to facilitate the commercial acceptance of compressed air energy storage (CAES) systems. The assessment is based on (1) detailed analyses of the market potential of utility storage technologies, (2) interviews with representatives of key participants in the CAES market, and (3) a decision analysis synthesizing much of the information about market and technology status. The results indicate a large potential market for CAES systems if the overall business environment for utilities improves. In addition, it appears that EPRI can have a valuable incremental impact in ensuring that utilities realize the potential of CAES by (1) continuing an aggressive information dissemination and technology transfer program, (2) working to ensure the success of the first United States CAES installation at Soyland Power Cooperative, (3) developing planning methods to allow utilities to evaluate CAES and other storage options more effectively and more realistically, and (4) supporting R and D to resolve residual uncertainties in first-generation CAES cost and performance characteristics.

  1. Compressed-air energy storage preliminary design and site development program in an aquifer. Volume 5, Part 1: Turbomachinery design

    NASA Astrophysics Data System (ADS)

    Berman, P. A.; Bonk, J. S.; Kobett, W. F.; Kosanovich, N. S.; Long, L. J.; Marinacci, D. J.

    1982-11-01

    The development of the design approach for a combustion turbine heat cycle and the major mechanical equipment for use by an electric utility at a selected aquifer air storage site is documented. A compressed air energy storage (CAES) system utilizes off peak electric power, available from base load power plants, to store compressed air underground in an aquifer. During subsequent periods, the stored air is extracted from the aquifer and used as an air supply for a generating combustion turbine expander. The aquifer has an initial discovery pressure of 840 psia. An initial air injection temperature of 1500 F was selected. The major mechanical equipment considered includes: the turbine motor/generator compressor train, intercooler and aftercooler system, and the exhaust gas regenerator. The cycle and machinery configuration and the specific mechanical equipment were selected for their Media site characteristics. These characteristics and the effect of component interdependency are considered when a conservative component design approach is established which satisfies the Media site CAES system requirements.

  2. Nonlinear compression of high energy fiber amplifier pulses in air-filled hypocycloid-core Kagome fiber.

    PubMed

    Guichard, Florent; Giree, Achut; Zaouter, Yoann; Hanna, Marc; Machinet, Guillaume; Debord, Benoît; Gérôme, Frédéric; Dupriez, Pascal; Druon, Frédéric; Hönninger, Clemens; Mottay, Eric; Benabid, Fetah; Georges, Patrick

    2015-03-23

    We report on the generation of 34 fs and 50 µJ pulses from a high energy fiber amplifier system with nonlinear compression in an air-filled hypocycloid-core Kagome fiber. The unique properties of such fibers allow bridging the gap between solid core fibers-based and hollow capillary-based post-compression setups, thereby operating with pulse energies obtained with current state-of-the-art fiber systems. The overall transmission of the compression setup is over 70%. Together with Yb-doped fiber amplifier technologies, Kagome fibers therefore appear as a promising tool for efficient generation of pulses with durations below 50 fs, energies ranging from 10 to several hundreds of µJ, and high average powers.

  3. Baseload power production from wind turbine arrays coupled to compressed air energy storage

    NASA Astrophysics Data System (ADS)

    Succar, Samir

    An analysis is presented of compressed air energy storage (CAES) and its potential for mitigating the intermittency of wind power, facilitating access to remote wind resources and transforming wind into baseload power. Although CAES has traditionally served other grid support applications, it is also well suited for wind balancing applications due its ability to provide long duration storage, its fast ramp rates and its high part load efficiencies. In addition, geologies potentially suitable for CAES appear to be abundant in regions with high-quality wind resources. This is especially true of porous rock formations, which have the potential to be the least costly air storage option for CAES. The characteristics of formations suitable for CAES storage and the challenges associated with using air as a storage fluid are discussed. An optimization framework is developed for analyzing the cost of baseload plants comprised of wind turbine arrays backed by natural gas-fired generating capacity and/or CAES. The optimization model analyzes changes to key aspects of the system configuration such as the wind turbine rating, the relative capacities of the system components, the size of the CAES storage reservoir and the wind turbine spacing. The response of the optimal system configuration to changes in natural gas price, greenhouse gas (GHG) emissions price, capital cost, and wind resource is also considered. Wind turbine rating is given focused attention because of its substantial impact on system configuration and output behavior. The generation cost of baseload wind is compared to that of other baseload options. To highlight the carbon-mitigation potential of baseload wind, the competition with coal power (with and without CO2 capture and storage, CCS) is given prominent attention. The ability of alternative options to compete under dispatch competition is explored thereby clarifying the extent to which baseload wind can defend high capacity factors in the market. This

  4. TECHNOLOGIES TO ENHANCE THE OPERATION OF EXISTING NATURAL GAS COMPRESSION INFRASTRUCTURE - MANIFOLD DESIGN FOR CONTROLLING ENGINE AIR BALANCE

    SciTech Connect

    Gary D. Bourn; Ford A. Phillips; Ralph E. Harris

    2005-12-01

    This document provides results and conclusions for Task 15.0--Detailed Analysis of Air Balance & Conceptual Design of Improved Air Manifolds in the ''Technologies to Enhance the Operation of Existing Natural Gas Compression Infrastructure'' project. SwRI{reg_sign} is conducting this project for DOE in conjunction with Pipeline Research Council International, Gas Machinery Research Council, El Paso Pipeline, Cooper Compression, and Southern Star, under DOE contract number DE-FC26-02NT41646. The objective of Task 15.0 was to investigate the perceived imbalance in airflow between power cylinders in two-stroke integral compressor engines and develop solutions via manifold redesign. The overall project objective is to develop and substantiate methods for operating integral engine/compressors in gas pipeline service, which reduce fuel consumption, increase capacity, and enhance mechanical integrity.

  5. Operational design and pressure response of large-scale compressed air energy storage in porous formations

    NASA Astrophysics Data System (ADS)

    Wang, Bo; Bauer, Sebastian

    2017-04-01

    With the rapid growth of energy production from intermittent renewable sources like wind and solar power plants, large-scale energy storage options are required to compensate for fluctuating power generation on different time scales. Compressed air energy storage (CAES) in porous formations is seen as a promising option for balancing short-term diurnal fluctuations. CAES is a power-to-power energy storage, which converts electricity to mechanical energy, i.e. highly pressurized air, and stores it in the subsurface. This study aims at designing the storage setup and quantifying the pressure response of a large-scale CAES operation in a porous sandstone formation, thus assessing the feasibility of this storage option. For this, numerical modelling of a synthetic site and a synthetic operational cycle is applied. A hypothetic CAES scenario using a typical anticline structure in northern Germany was investigated. The top of the storage formation is at 700 m depth and the thickness is 20 m. The porosity and permeability were assumed to have a homogenous distribution with a value of 0.35 and 500 mD, respectively. According to the specifications of the Huntorf CAES power plant, a gas turbine producing 321 MW power with a minimum inlet pressure of 43 bars at an air mass flowrate of 417 kg/s was assumed. Pressure loss in the gas wells was accounted for using an analytical solution, which defines a minimum bottom hole pressure of 47 bars. Two daily extraction cycles of 6 hours each were set to the early morning and the late afternoon in order to bypass the massive solar energy production around noon. A two-year initial filling of the reservoir with air and ten years of daily cyclic operation were numerically simulated using the Eclipse E300 reservoir simulator. The simulation results show that using 12 wells the storage formation with a permeability of 500 mD can support the required 6-hour continuous power output of 321MW, which corresponds an energy output of 3852 MWh per

  6. Siting-selection study for the Soyland Power Cooperative, Inc. , compressed-air energy-storage system (CAES)

    SciTech Connect

    Not Available

    1982-01-01

    A method used for siting a compressed air energy storage (CAES) system using geotechnical and environmental criteria is explained using the siting of a proposed 220 MW water-compensated CAES plant in Illinois as an example. Information is included on the identification and comparative ranking of 28 geotechnically and environmental sites in Illinois, the examination of fatal flaws, e.g., mitigation, intensive studies, costly studies, permit denials, at 7 sites; and the selection of 3 sites for further geological surveying. (LCL)

  7. Preliminary design study of compressed-air energy storage in a salt dome. Volume 1: Executive summary

    NASA Astrophysics Data System (ADS)

    1982-01-01

    The preliminary design and cost estimate of a compressed air energy storage (CAES) plant located in the Middle South Utilities (MSU) system are summarized. The 220 MWe CAES plant stores air in two solution mined salt caverns. The facility criteria, site selection and the turbomachinery and auxiliaries, and an outline of the proposed procedure for developing the caverns are described. The preliminary CAES plant design was prepared and the capital cost estimate, cash low and project schedule were developed. A CAES plant does not appear to be economic in the MSU system before the mid 1990s which is due to the unique features of the MSU system.

  8. Tension-Compression Fatigue of a Nextel™720/alumina Composite at 1200 °C in Air and in Steam

    NASA Astrophysics Data System (ADS)

    Lanser, R. L.; Ruggles-Wrenn, M. B.

    2016-08-01

    Tension-compression fatigue behavior of an oxide-oxide ceramic-matrix composite was investigated at 1200 °C in air and in steam. The composite is comprised of an alumina matrix reinforced with Nextel™720 alumina-mullite fibers woven in an eight harness satin weave (8HSW). The composite has no interface between the fiber and matrix, and relies on the porous matrix for flaw tolerance. Tension-compression fatigue behavior was studied for cyclical stresses ranging from 60 to 120 MPa at a frequency of 1.0 Hz. The R ratio (minimum stress to maximum stress) was -1.0. Fatigue run-out was defined as 105 cycles and was achieved at 80 MPa in air and at 70 MPa in steam. Steam reduced cyclic lives by an order of magnitude. Specimens that achieved fatigue run-out were subjected to tensile tests to failure to characterize the retained tensile properties. Specimens subjected to prior cyclic loading in air retained 100 % of their tensile strength. The steam environment severely degraded tensile properties. Tension-compression cyclic loading was considerably more damaging than tension-tension cyclic loading. Composite microstructure, as well as damage and failure mechanisms were investigated.

  9. Site specific comparison of H2, CH4 and compressed air energy storage in porous formations

    NASA Astrophysics Data System (ADS)

    Tilmann Pfeiffer, Wolf; Wang, Bo; Bauer, Sebastian

    2016-04-01

    The supply of energy from renewable sources like wind or solar power is subject to fluctuations determined by the climatic and weather conditions, and shortage periods can be expected on the order of days to weeks. Energy storage is thus required if renewable energy dominates the total energy production and has to compensate the shortages. Porous formations in the subsurface could provide large storage capacities for various energy carriers, such as hydrogen (H2), synthetic methane (CH4) or compressed air (CAES). All three energy storage options have similar requirements regarding the storage site characteristics and consequently compete for suitable subsurface structures. The aim of this work is to compare the individual storage methods for an individual storage site regarding the storage capacity as well as the achievable delivery rates. This objective is pursued using numerical simulation of the individual storage operations. In a first step, a synthetic anticline with a radius of 4 km, a drop of 900 m and a formation thickness of 20 m is used to compare the individual storage methods. The storage operations are carried out using -depending on the energy carrier- 5 to 13 wells placed in the top of the structure. A homogeneous parameter distribution is assumed with permeability, porosity and residual water saturation being 500 mD, 0.35 and 0.2, respectively. N2 is used as a cushion gas in the H2 storage simulations. In case of compressed air energy storage, a high discharge rate of 400 kg/s equating to 28.8 mio. m³/d at surface conditions is required to produce 320 MW of power. Using 13 wells the storage is capable of supplying the specified gas flow rate for a period of 31 hours. Two cases using 5 and 9 wells were simulated for both the H2 and the CH4 storage operation. The target withdrawal rates of 1 mio. sm³/d are maintained for the whole extraction period of one week in all simulations. However, the power output differs with the 5 well scenario producing

  10. Citizen Hydrology and Compressed-Air Hydropower for Rural Electrification in Haiti

    NASA Astrophysics Data System (ADS)

    Allen, S. M.

    2015-12-01

    At the present time, only one in eight residents of Haiti has access to electricity. Two recent engineering and statistical innovations have the potential for vastly reducing the cost of installation of hydropower in Haiti and the rest of the developing world. The engineering innovation is that wind, solar and fluvial energy have been used to compress air for generation of electricity for only 20 per megawatt-hour, in contrast to the conventional World Bank practice of funding photovoltaic cells for 156 per megawatt-hour. The installation of hydropower requires a record of stream discharge, which is conventionally obtained by installing a gaging station that automatically monitors gage height (height of the water surface above a fixed datum). An empirical rating curve is then used to convert gage height to stream discharge. The multiple field measurements of gage height and discharge over a wide range of discharge values that are required to develop and maintain a rating curve require a manpower of hydrologic technicians that is prohibitive in remote and impoverished areas of the world. The statistical innovation is that machine learning has been applied to the USGS database of nearly four million simultaneous measurements of gage height and discharge to develop a new classification of rivers so that a rating curve can be developed solely from the stream slope, channel geometry, horizontal and vertical distances to the nearest upstream and downstream confluences, and two pairs of discharge - gage height measurements. The objective of this study is to organize local residents to monitor gage height at ten stream sites in the northern peninsula of Haiti over a one-year period in preparation for installation of hydropower at one of the sites. The necessary baseline discharge measurements and channel surveying are being carried out for conversion of gage height to discharge. Results will be reported at the meeting.

  11. Forced-Air Warming During Pediatric Surgery: A Randomized Comparison of a Compressible with a Noncompressible Warming System.

    PubMed

    Triffterer, Lydia; Marhofer, Peter; Sulyok, Irene; Keplinger, Maya; Mair, Stefan; Steinberger, Markus; Klug, Wolfgang; Kimberger, Oliver

    2016-01-01

    Perioperative hypothermia is a common problem, challenging the anesthesiologist and influencing patient outcome. Efficient and safe perioperative active warming is therefore paramount; yet, it can be particularly challenging in pediatric patients. Forced-air warming technology is the most widespread patient-warming option, with most forced-air warming systems consisting of a forced-air blower connected to a compressible, double layer plastic and/or a paper blanket with air holes on the patient side. We compared an alternative, forced-air, noncompressible, under-body patient-warming mattress (Baby/Kleinkinddecke of MoeckWarmingSystems, Moeck und Moeck GmbH; group MM) with a standard, compressible warming mattress system (Pediatric Underbody, Bair Hugger, 3M; group BH). The study included 80 patients aged <2 years, scheduled for elective surgery. After a preoperative core temperature measurement, the patients were placed on the randomized mattress in the operation theater and 4 temperature probes were applied rectally and to the patients' skin. The warming devices were turned on as soon as possible to the level for pediatric patients as recommended by the manufacturer (MM = 40°C, BH = 43°C). There was a distinct difference of temperature slope between the 2 groups: core temperatures of patients in the group MM remained stable and mean of the core temperature of patients in the group BH increased significantly (difference: +1.48°C/h; 95% confidence interval, 0.82-2.15°C/h; P = 0.0001). The need for temperature downregulation occurred more often in the BH group, with 22 vs 7 incidences (RR, 3.14; 95% confidence interval, 1.52-6.52; P = 0.0006). Skin temperatures were all lower in the MM group. Perioperatively, no side effects related to a warming device were observed in any group. Both devices are feasible choices for active pediatric patient warming, with the compressible mattress system being better suited to increase core temperature. The use of lower pediatric

  12. Helical Explosive Flux Compression Generator Research at the Air Force Research Laboratory

    DTIC Science & Technology

    1999-06-01

    Air Force Research Laboratory Kirtland AFB...ORGANIZATION NAME(S) AND ADDRESS(ES) Directed Energy Directorate, Air Force Research Laboratory Kirtland AFB, NM 8. PERFORMING ORGANIZATION REPORT...in support of the Air Force Research Laboratory ( AFRL ) explosive pulsed power program. These include circuit codes such as Microcap and

  13. Preliminary design study of underground pumped hydro and compressed-air energy storage in hard rock. Volume 1: Executive summary

    NASA Astrophysics Data System (ADS)

    1981-05-01

    A preliminary design study of water compensated Compressed Air Energy Storage (CAES) and Underground Pumped Hydroelectric (UPH) plants for siting in geological conditions suitable for hard rock excavations was performed. The study was divided into five primary tasks as follows: establishment of design criteria and analysis of impact on power system; selection of site and establishment of site characteristics; formulation of design approaches; assessment of environmental and safety aspects; and preparation of preliminary design of plant. The salient aspects considered and the conclusions reached during the consideration of the five primary tasks for both CAES and UPH are presented.

  14. Performance of a Compression-ignition Engine with a Precombustion Chamber Having High-Velocity Air Flow

    NASA Technical Reports Server (NTRS)

    Spanogle, J A; Moore, C S

    1931-01-01

    Presented here are the results of performance tests made with a single-cylinder, four stroke cycle, compression-ignition engine. These tests were made on a precombustion chamber type of cylinder head designed to have air velocity and tangential air flow in both the chamber and cylinder. The performance was investigated for variable load and engine speed, type of fuel spray, valve opening pressure, injection period and, for the spherical chamber, position of the injection spray relative to the air flow. The pressure variations between the pear-shaped precombustion chamber and the cylinder for motoring and full load conditions were determined with a Farnboro electric indicator. The combustion chamber designs tested gave good mixing of a single compact fuel spray with the air, but did not control the ensuing combustion sufficiently. Relative to each other, the velocity of air flow was too high, the spray dispersion by injection too great, and the metering effect of the cylinder head passage insufficient. The correct relation of these factors is of the utmost importance for engine performance.

  15. EFFECT OF LUBRICANT CONTAMINATION ON THE PERFORMANCE AND RELIABILITY OF HEAT PUMPS CHARGED WITH R-407C.

    EPA Science Inventory

    The report gives results of the development of new data that can be used to determine the effect of mineral oil contamination on the reliability of a heat pump system operating with a new hydrofluorocarbon mixture and polyol ester lubricant, to assess any performance degradation ...

  16. EFFECT OF LUBRICANT CONTAMINATION ON THE PERFORMANCE AND RELIABILITY OF HEAT PUMPS CHARGED WITH R-407C.

    EPA Science Inventory

    The report gives results of the development of new data that can be used to determine the effect of mineral oil contamination on the reliability of a heat pump system operating with a new hydrofluorocarbon mixture and polyol ester lubricant, to assess any performance degradation ...

  17. Petrologic and petrophysical evaluation of the Dallas Center Structure, Iowa, for compressed air energy storage in the Mount Simon Sandstone.

    SciTech Connect

    Heath, Jason E.; Bauer, Stephen J.; Broome, Scott Thomas; Dewers, Thomas A.; Rodriguez, Mark A

    2013-03-01

    The Iowa Stored Energy Plant Agency selected a geologic structure at Dallas Center, Iowa, for evaluation of subsurface compressed air energy storage. The site was rejected due to lower-than-expected and heterogeneous permeability of the target reservoir, lower-than-desired porosity, and small reservoir volume. In an initial feasibility study, permeability and porosity distributions of flow units for the nearby Redfield gas storage field were applied as analogue values for numerical modeling of the Dallas Center Structure. These reservoir data, coupled with an optimistic reservoir volume, produced favorable results. However, it was determined that the Dallas Center Structure cannot be simplified to four zones of high, uniform permeabilities. Updated modeling using field and core data for the site provided unfavorable results for air fill-up. This report presents Sandia National Laboratories petrologic and petrophysical analysis of the Dallas Center Structure that aids in understanding why the site was not suitable for gas storage.

  18. Application of wavelet filtering and Barker-coded pulse compression hybrid method to air-coupled ultrasonic testing

    NASA Astrophysics Data System (ADS)

    Zhou, Zhenggan; Ma, Baoquan; Jiang, Jingtao; Yu, Guang; Liu, Kui; Zhang, Dongmei; Liu, Weiping

    2014-10-01

    Air-coupled ultrasonic testing (ACUT) technique has been viewed as a viable solution in defect detection of advanced composites used in aerospace and aviation industries. However, the giant mismatch of acoustic impedance in air-solid interface makes the transmission efficiency of ultrasound low, and leads to poor signal-to-noise (SNR) ratio of received signal. The utilisation of signal-processing techniques in non-destructive testing is highly appreciated. This paper presents a wavelet filtering and phase-coded pulse compression hybrid method to improve the SNR and output power of received signal. The wavelet transform is utilised to filter insignificant components from noisy ultrasonic signal, and pulse compression process is used to improve the power of correlated signal based on cross-correction algorithm. For the purpose of reasonable parameter selection, different families of wavelets (Daubechies, Symlet and Coiflet) and decomposition level in discrete wavelet transform are analysed, different Barker codes (5-13 bits) are also analysed to acquire higher main-to-side lobe ratio. The performance of the hybrid method was verified in a honeycomb composite sample. Experimental results demonstrated that the proposed method is very efficient in improving the SNR and signal strength. The applicability of the proposed method seems to be a very promising tool to evaluate the integrity of high ultrasound attenuation composite materials using the ACUT.

  19. Preliminary design study of compressed-air energy storage in a salt dome. Volume 6: CAES plant design

    NASA Astrophysics Data System (ADS)

    1982-04-01

    The preliminary plant design for a compressed air energy storage (CAES) plant is presented. The design is based upon the facility criteria; the specific site; and the systems, subsystems. The compressed air is stored in two solution mined caverns in the salt dome. The details concerning the major equipment and the operation of the mechanical systems are described. The project schedule from start of licensing to commercial operation is estimated to be 70 months, with actual construction (including dewatering of the caverns) estimated for 39 months. Based on the cost estimate developed in this task and the modified financial data and fuel cost projections, the economic introduction of CAES into the MSS system was examined for the No. 2 oil-fired plant. The economic analysis did not extend beyond the year 1988. The economic introduction of CAES in the MSS system before 1990 is unlikely because the older oil fired units in the MSS system may be economically used for cycling and peaking, if required. For a system with a different composition of generating units, CAES may be economical at an earlier data.

  20. Modeling the Use of Mine Waste Rock as a Porous Medium Reservoir for Compressed Air Energy Storage

    NASA Astrophysics Data System (ADS)

    Donelick, R. A.; Donelick, M. B.

    2016-12-01

    We are studying the engineering and economic feasibilities of constructing Big Mass Battery (BiMBy) compressed air energy storage devices using some of the giga-tonnes of annually generated and historically produced mine waste rock/overburden/tailings (waste rock). This beneficial use of waste rock is based on the large mass (Big Mass), large pore volume, and wide range of waste rock permeabilities available at some large open pit metal mines and coal strip mines. Porous Big Mass is encapsulated and overlain by additional Big Mass; compressed air is pumped into the encapsulated pore space when renewable energy is abundant; compressed air is released from the encapsulated pore space to run turbines to generate electricity at the grid scale when consumers demand electricity. Energy storage capacity modeling: 1) Yerington Pit, Anaconda Copper Mine, Yerington, NV (inactive metal mine): 340 Mt Big Mass, energy storage capacity equivalent to 390k-710k home batteries of size 10 kW•h/charge, assumed 20% porosity, 50% overall efficiency. 2) Berkeley Pit, Butte Copper Mine, Butte, MT (inactive metal mine): 870 Mt Big Mass, energy storage capacity equivalent to 1.4M-2.9M home batteries of size 10 kW•h/charge, assumed 20% porosity, 50% overall efficiency. 3) Rosebud Mine, Colstrip, MT (active coal strip mine): 87 Mt over 2 years, energy storage capacity equivalent to 45k-67k home batteries of size 10 kW•h/charge, assumed 30% porosity, 50% overall efficiency. Encapsulating impermeable layer modeling: Inactive mine pits like Yerington Pit and Berkeley Pit, and similar active pits, have associated with them low permeability earthen material (silt and clay in Big Mass) at sufficient quantities to manufacture an encapsulating structure with minimal loss of efficiency due to leakage, a lifetime of decades or even centuries, and minimal need for the use of geomembranes. Active coal strip mines like Rosebud mine have associated with them low permeability earthen material such as

  1. Hybrid Energy Storage System Based on Compressed Air and Super-Capacitors with Maximum Efficiency Point Tracking (MEPT)

    NASA Astrophysics Data System (ADS)

    Lemofouet, Sylvain; Rufer, Alfred

    This paper presents a hybrid energy storage system mainly based on Compressed Air, where the storage and withdrawal of energy are done within maximum efficiency conditions. As these maximum efficiency conditions impose the level of converted power, an intermittent time-modulated operation mode is applied to the thermodynamic converter to obtain a variable converted power. A smoothly variable output power is achieved with the help of a supercapacitive auxiliary storage device used as a filter. The paper describes the concept of the system, the power-electronic interfaces and especially the Maximum Efficiency Point Tracking (MEPT) algorithm and the strategy used to vary the output power. In addition, the paper introduces more efficient hybrid storage systems where the volumetric air machine is replaced by an oil-hydraulics and pneumatics converter, used under isothermal conditions. Practical results are also presented, recorded from a low-power air motor coupled to a small DC generator, as well as from a first prototype of the hydro-pneumatic system. Some economical considerations are also made, through a comparative cost evaluation of the presented hydro-pneumatic systems and a lead acid batteries system, in the context of a stand alone photovoltaic home application. This evaluation confirms the cost effectiveness of the presented hybrid storage systems.

  2. A cost-effective and fuel-conserving nonelectric air conditioner that combines engine-driven compression and absorption cycles

    SciTech Connect

    Wicks, F.

    1988-01-01

    A natural-gas-fueled electricity-producing condensing furnace with the potential of being mass produced at a cost of less than $1000 and providing a cost-effective and highly fuel-conserving alternative to virtually every residential gas furnace in the world has been developed. While this is a new system, it completely consists of existing mass-produced components including single-cylinder air-cooled engines, induction motors/generators, and control devices. Thus, timely commercialization can be expected and an important new energy technology and industry can result. However, all the benefits of this electricity-producing furnace occur during the winter. This has stimulated the search for a new system that can provide comparable benefits in terms of fuel conservation, the environment, and electric utility peak reduction during the summer, along with the prospects of a new and efficient new use for the natural gas surpluses that occur during the summer. The resulting system, which can use existing component equipment, is a commercial-size nonelectric air conditioner that consists of an automobile-type engine converted to natural gas, or possibly a diesel or combustion turbine, driving a Freon compression cycle, with virtually all of the engine reject heat from the exhaust and from the engine cooling system driving a conventional absorption air conditioning cycle.

  3. Effect of air-entry angle on performance of a 2-stroke-cycle compression-ignition engine

    NASA Technical Reports Server (NTRS)

    Earle, Sherod L; Dutee, Francis J

    1937-01-01

    An investigation was made to determine the effect of variations in the horizontal and vertical air-entry angles on the performance characteristics of a single-cylinder 2-stroke-cycle compression-ignition test engine. Performance data were obtained over a wide range of engine speed, scavenging pressure, fuel quantity, and injection advance angle with the optimum guide vanes. Friction and blower-power curves are included for calculating the indicated and net performances. The optimum horizontal air-entry angle was found to be 60 degrees from the radial and the optimum vertical angle to be zero, under which conditions a maximum power output of 77 gross brake horsepower for a specific fuel consumption of 0.52 pound per brake horsepower-hour was obtained at 1,800 r.p.m. and 16-1/2 inches of Hg scavenging pressure. The corresponding specific output was 0.65 gross brake horsepower per cubic inch of piston displacement. Tests revealed that the optimum scavenging pressure increased linearly with engine speed. The brake mean effective pressure increased uniformly with air quantity per cycle for any given vane angle and was independent of engine speed and scavenging pressure.

  4. Compressed-air energy storage preliminary design and site-development program in an aquifer. Volume 2: Utility-system planning

    NASA Astrophysics Data System (ADS)

    1982-06-01

    The benefits derived from the integration of a compressed air energy storage facility with a hypothetical electrical network were analyzed. The analysis was based on three study scenarios each having a target generation mix of 65% base, 25% intermediate, and 10% peaking capacity. Scenarios of 100% coal, 50% coal and 50% nuclear, and 100% nuclear base load capacity additions were examined. Final results of the analyses indicate favorable economics when compressed air energy storage is installed as an alternative to combustion turbine peaking capacity on a system with a significant amount of oil-fired generation.

  5. Compressed air energy storage: Preliminary design and site development program in an aquifer. Task 1: Establish facility design criteria and utility benefits

    NASA Astrophysics Data System (ADS)

    1980-10-01

    Compressed air energy storage (CAES) stores mechanical energy in the form of compressed air during off-peak hours, using power supplied by a large, high efficiency baseload power plant. At times of high electrical demand, the compressed air is drawn from storage and is heated in a combustor by the burning of fuel oil, after which the air is expanded in a turbine. Essentially all of the turbine output can be applied to the generation of electricity, unlike a conventional gas turbine which expends approximately two-thirds of the turbine shaft power in driving the air compressor. The separation of the compression and generation modes in the system results in increased net generation and greater premium fuel economy. Work performed in establishing facility design criteria for a CAES system with aquifer storage includes: determination of initial design bases; preliminary analysis of the CAES system; development of data for site-specific analysis of the CAES system; detailed analysis of the CAES system for three selected heat cycles; CAES power plant design; and an economic analysis of CAES.

  6. Compressed air energy storage: preliminary design and site development program in an aquifer. Final draft, Task 1: establish facility design criteria and utility benefits

    SciTech Connect

    1980-10-01

    Compressed air energy storage (CAES) has been identified as one of the principal new energy storage technologies worthy of further research and development. The CAES system stores mechanical energy in the form of compressed air during off-peak hours, using power supplied by a large, high-efficiency baseload power plant. At times of high electrical demand, the compressed air is drawn from storage and is heated in a combustor by the burning of fuel oil, after which the air is expanded in a turbine. In this manner, essentially all of the turbine output can be applied to the generation of electricity, unlike a conventional gas turbine which expends approximately two-thirds of the turbine shaft power in driving the air compressor. The separation of the compression and generation modes in the CAES system results in increased net generation and greater premium fuel economy. The use of CAES systems to meet the utilities' high electrical demand requirements is particularly attractive in view of the reduced availability of premium fuels such as oil and natural gas. This volume documents the Task 1 work performed in establishing facility design criteria for a CAES system with aquifer storage. Information is included on: determination of initial design bases; preliminary analysis of the CAES system; development of data for site-specific analysis of the CAES system; detailed analysis of the CAES system for three selected heat cycles; CAES power plant design; and an economic analysis of CAES.

  7. Geotechnical factors and guidelines for storage of compressed air in solution-mined salt cavities

    NASA Astrophysics Data System (ADS)

    Allen, R. D.; Doherty, T. J.; Thoms, R. L.

    1982-05-01

    The state of knowledge about utilization of solution mined salt cavities for CAES including laboratory experiments, numerical modeling, field characterization, solution mining experience, and operating parameters is outlined. Topics evaluated include: cavern geometry and size; long term creep and creep rupture of rock salt; effects of pressure and temperature loading rates; low frequency fatigue; progressive deterioration of salt fabric with possible air penetration; cavern monitoring methods; and salt properties at nonambient conditions. The only CAES operational facility in the world uses two solution mined salt cavern for air storage and is operating successfully. Stability critera for solution mined salt caverns.

  8. [Management of penile trauma from compressed air gun in a child].

    PubMed

    Girón-Vallejo, O; Zambudio, G; Ruiz-Pruneda, R; Hernindez, J P; Ruiz-Jiménez, J I

    2011-01-01

    We report on a 6-year old child with a penile injury resulting in the inclusion of a pellet in the cavernous body, by a fortuitous shot. Conservative approach with elective extraction of the bullet and cavernous body repair led to a satisfactory result, in better anatomic conditions. The patient did not have any perioperative complication. Accidents by air weapons are particularly important in children, because these weapons are erroneously considered as toys. Air gun injuries to head, neck and thorax have been often published, but these injuries are rare in the chidren genitourinary area.

  9. Preliminary design study of underground pumped hydro and compressed-air energy storage in hard rock. Volume 5: Site selection

    NASA Astrophysics Data System (ADS)

    1981-04-01

    A six-step site selection process undertaken to identify and subsequently rank potential sites suitable for either an underground pumped hydroelectric (UPH) facility, or a water-compensated hard-rock cavern compressed air energy storage (CAES) facility is described. The region of study was confined to the service area of the Potomac Electric Power Company (PEPCO) and contiguous areas. Overriding considerations related to geology, environmental impact and transmission-line routing were studies within the context of minimizing plant costs. The selection process led to the identification of several sites suitable for the development of either a CAES or an UPH facility. Design development and site exploration at the selected site are described.

  10. Preliminary evaluation of coal-fired fluid bed combustion-augmented compressed air energy storage power plants

    NASA Astrophysics Data System (ADS)

    Lessard, R. D.; Giramonti, A. J.; Merrick, D.

    1980-03-01

    This paper presents highlights of an ongoing study program to assess the technical and economic feasibility of advanced concepts for generating peak-load electric power from a compressed air energy storage (CAES) power plant incorporating a coal-fired fluid bed combustor (FBC). It reviews the analyses performed to select an FBC/CAES power plant system configuration for the subsequent conceptual design phase of the study. Included in this review are: the design and operating considerations involved with integrating either an atmospheric or a pressurized fluid bed combustor with a CAES system to yield practical system configurations; the integration of system configurations; the parametric performance of these system configurations; and the preliminary screening which considered performance, cost, and technical risk and led to the identification of an open-bed PFBC/CAES system as having the greatest near-term commercialization potential.

  11. Homemade Firearm Suicide With Dumbbell Pipe Triggering by an Air-Compressed Gun: Case Report and Review of Literature.

    PubMed

    Le Garff, Erwan; Delannoy, Yann; Mesli, Vadim; Berthezene, Jean Marie; Morbidelli, Philippe; Hédouin, Valéry

    2015-12-01

    Firearm suicides are frequent and well described in the forensic literature, particularly in Europe and the United States. However, the use of homemade and improvised firearms is less well described. The present case reports a suicide with an original improvised gun created using an air-compressed pellet gun and a dumbbell pipe. The aims of this study were to describe the scene, the external examination of the corpse, the body scan, and the autopsy; to understand the mechanism of death; and to compare the results with a review of the forensic literature to highlight the epidemiology of homemade firearm use, the tools used for homemade and improvised firearms in suicides versus homicides, and the manners in which homemade firearms are used (homicide or suicide, particularly in complex suicide cases).

  12. Considerations on the effect of wind-tunnel walls on oscillating air forces for two-dimensional subsonic compressible flow

    NASA Technical Reports Server (NTRS)

    Runyan, Harry L; Watkins, Charles E

    1953-01-01

    This report treats the effect of wind-tunnel walls on the oscillating two-dimensional air forces in a compressible medium. The walls are simulated by the usual method of placing images at appropriate distances above and below the wing. An important result shown is that, for certain conditions of wing frequency, tunnel height, and Mach number, the tunnel and wing may form a resonant system so that the forces on the wing are greatly changed from the condition of no tunnel walls. It is pointed out that similar conditions exist for three-dimensional flow in circular and rectangular tunnels and apparently, within certain Mach number ranges, in tunnels of nonuniform cross section or even in open tunnels or jets.

  13. The breakdown voltage characteristics of compressed ambient air microdischarges from direct current to 10.2 MHz

    NASA Astrophysics Data System (ADS)

    Klas, M.; Moravsky, L.; Matejčik, Š.; Zahoran, M.; Martišovitš, V.; Radjenović, B.; Radmilović-Radjenović, M.

    2017-05-01

    This paper presents the results of the experimental and simulation studies of the breakdown characteristics of microdischarges in compressed ambient air under the influence of static and time-varying electric fields, up to radio-frequencies. The measurements were performed for sphere to plane geometry of the electrodes separated from 5 μm to 100 μm, within the pressure range 760 Torr to 3800 Torr. For gaps of the order of a few micrometers, it is not possible to properly obtain the left-hand side of the Paschen curve; and the Townsend mechanism is no longer suitable. Deviations are also observable in the direction of lower breakdown potential that appear at the right of the minimum of the direct-current breakdown voltage curves indicating that accumulated space charge plays an important role in enhanced field emission. The experimental data agree well with the simulation results obtained by a one-dimensional particle-in-cell/Monte Carlo collision code including field emission effects. Their fit to a simple formula describing the dependence of the breakdown voltage on the product of the pressure and the gap size is suggested. Based on the measured breakdown voltage curves, the effective secondary electron emission coefficients have been determined. This work especially focuses on the effect of the electrode surface degradation on the breakdown characteristics at high pressure and high frequency. It is observed that in the case of direct-current and low frequency discharges, there is no significant influence of the electrode surface degradation on the breakdown voltage and the effective yields. However, for higher frequencies, the breakdown voltages are lower and the effective yields are much higher after degradation. The obtained results represent our attempt to derive a preliminary understanding of the governing breakdown processes in compressed air microdischarges.

  14. Technical and economic assessment of fluidized-bed-augmented compressed-air energy-storage system: system load following capability

    SciTech Connect

    Lessard, R.D.; Blecher, W.A.; Merrick, D.

    1981-09-01

    The load-following capability of fluidized bed combustion-augmented compressed air energy storage systems was evaluated. The results are presented in two parts. The first part is an Executive Summary which provides a concise overview of all major elements of the study including the conclusions, and, second, a detailed technical report describing the part-load and load following capability of both the pressurized fluid bed combustor and the entire pressurized fluid bed combustor/compressed air energy storage system. The specific tasks in this investigation were to: define the steady-state, part-load operation of the CAES open-bed PFBC; estimate the steady-state, part-load performance of the PFBC/CAES system and evaluate any possible operational constraints; simulate the performance of the PFBC/CAES system during transient operation and assess the load following capability of the system; and establish a start-up procedure for the open-bed PFBC and evaluate the impact of this procedure. The conclusions are encouraging and indicate that the open-bed PFBC/CAES power plant should provide good part-load and transient performance, and should have no major equipment-related constraints, specifically, no major problems associated with the performance or design of either the open-end PFBC or the PFBC/CAES power plant in steady-state, part-load operation are envisioned. The open-bed PFBC/CAES power plant would have a load following capability which would be responsive to electric utility requirements for a peak-load power plant. The open-bed PFBC could be brought to full operating conditions within 15 min after routine shutdown, by employing a hot-start mode of operation. The PFBC/CAES system would be capable of rapid changes in output power (12% of design load per minute) over a wide output power range (25% to 100% of design output). (LCL)

  15. Characterizing Excavation Damaged Zone and Stability of Pressurized Lined Rock Caverns for Underground Compressed Air Energy Storage

    NASA Astrophysics Data System (ADS)

    Kim, Hyung-Mok; Rutqvist, Jonny; Jeong, Ju-Hwan; Choi, Byung-Hee; Ryu, Dong-Woo; Song, Won-Kyong

    2013-09-01

    In this paper, we investigate the influence of the excavation damaged zone (EDZ) on the geomechanical performance of compressed air energy storage (CAES) in lined rock caverns. We conducted a detailed characterization of the EDZ in rock caverns that have been excavated for a Korean pilot test program on CAES in (concrete) lined rock caverns at shallow depth. The EDZ was characterized by measurements of P- and S-wave velocities and permeability across the EDZ and into undisturbed host rock. Moreover, we constructed an in situ concrete lining model and conducted permeability measurements in boreholes penetrating the concrete, through the EDZ and into the undisturbed host rock. Using the site-specific conditions and the results of the EDZ characterization, we carried out a model simulation to investigate the influence of the EDZ on the CAES performance, in particular related to geomechanical responses and stability. We used a modeling approach including coupled thermodynamic multiphase flow and geomechanics, which was proven to be useful in previous generic CAES studies. Our modeling results showed that the potential for inducing tensile fractures and air leakage through the concrete lining could be substantially reduced if the EDZ around the cavern could be minimized. Moreover, the results showed that the most favorable design for reducing the potential for tensile failure in the lining would be a relatively compliant concrete lining with a tight inner seal, and a relatively stiff (uncompliant) host rock with a minimized EDZ. Because EDZ compliance depends on its compressibility (or modulus) and thickness, care should be taken during drill and blast operations to minimize the damage to the cavern walls.

  16. Experimental study of convective heat transfer of compressed air flow in radially rotating ducts

    SciTech Connect

    Hwang, G.J,; Tzeng, S.C.; Mao, C.P.

    1999-07-01

    The convective heat transfer of pressurized air flow in radially rotating serpentine channel is investigated experimentally in the present study. The main governing parameters are the Prandtl number, the Reynolds number for forced convection, the rotation number for the Coriolis force induced cross stream secondary flow and the Grashof number for natural convection. To simulate the operation conditions of a real gas turbine, the present study kept the parameters in the test rig approximately the same as those in a real engine. The air in the present serpentine channel was pressurized to increase the air density for making up the low rotational speed in the experiment. Before entering the rotating ducts, the air was also cooled to gain a high density ratio of approximately 1/3 in the ducts. This high density ratio will give a similar order of magnitude of Grashof number in a real operation condition. The local heat transfer rate on the four channel walls are present and compared with that in existing literature.

  17. Geotechnical factors and guidelines for storage of compressed air in solution-mined salt cavities

    SciTech Connect

    Allen, R.D.; Doherty, T.J.; Thoms, R.L.

    1982-05-01

    The state of knowledge about utilization of solution-mined salt cavities for CAES including laboratory experiments, numerical modeling, field characterization, solution mining experience, and operating parameters is outlined in this report. Topics evaluated in recent studies include: cavern geometry and size; long-term creep and creep rupture of rock salt; effects of pressure and temperature loading rates; low frequency fatigue; progressive deterioration of salt fabric with possible air penetration; cavern monitoring methods; and salt properties at nonambient conditions. Currently, the only CAES operational facility in the world is located at Huntorf, West Germany. This CAES facility uses two solution-mined salt caverns for air storage and has been operating successfully for more than 2 years. Stability criteria for solution-mined salt caverns from the Huntorf facility and recent field and laboratory studies are included in this report.

  18. Water coning in porous media reservoirs for compressed air energy storage

    SciTech Connect

    Wiles, L.E.; McCann, R.A.

    1981-06-01

    The general purpose of this work is to define the hydrodynamic and thermodynamic response of a CAES porous media reservoir subjected to simulated air mass cycling. This research will assist in providing design guidelines for the efficient and stable operation of the air storage reservoir. This report presents the analysis and results for the two-phase (air-water), two-dimensional, numerical modeling of CAES porous media reservoirs. The effects of capillary pressure and relative permeability were included. The fluids were considered to be immisicible; there was no phase change; and the system was isothermal. The specific purpose of this analysis was to evaluate the reservoir parameters that were believed to be important to water coning. This phenomenon may occur in reservoirs in which water underlies the air storage zone. It involves the possible intrusion of water into the wellbore or near-wellbore region. The water movement is in response to pressure gradients created during a reservoir discharge cycle. Potential adverse effects due to this water movement are associated with the pressure response of the reservoir and the geochemical stability of the near-wellbore region. The results obtained for the simulated operation of a CAES reservoir suggest that water coning should not be a severe problem, due to the slow response of the water to the pressure gradients and the relatively short duration in which those gradients exist. However, water coning will depend on site-specific conditions, particularly the fluid distributions following bubble development, and, therefore, a water coning analysis should be included as part of site evaluation.

  19. Compressed-Air Energy Storage: Preliminary design and site development program in an aquifer. Volume 7: Environmental, safety, and licensing considerations

    NASA Astrophysics Data System (ADS)

    1981-07-01

    The behavior and suitability of aquifers as compressed-air energy storage (CAFS) sites was studied. The probability, severity, and recommended control measures for the environmental and safety impacts that could result from the construction and operation of a CAES facility are described. The permits and approvals that would be required and the time estimated for their acquisition are also described.

  20. Technical and economic assessment of fluidized bed augmented compressed air energy-storage system. Volume II. Introduction and technology assessment

    SciTech Connect

    Giramonti, A.J.; Lessard, R.D.; Merrick, D.; Hobson, M.J.

    1981-09-01

    The results are described of a study subcontracted by PNL to the United Technologies Research Center on the engineering feasibility and economics of a CAES concept which uses a coal fired, fluidized bed combustor (FBC) to heat the air being returned from storage during the power production cycle. By burning coal instead of fuel oil, the CAES/FBC concept can completely eliminate the dependence of compressed air energy storage on petroleum fuels. The results of this assessment effort are presented in three volumes. Volume II presents a discussion of program background and an in-depth coverage of both fluid bed combustion and turbomachinery technology pertinent to their application in a CAES power plant system. The CAES/FBC concept appears technically feasible and economically competitive with conventional CAES. However, significant advancement is required in FBC technology before serious commercial commitment to CAES/FBC can be realized. At present, other elements of DOE, industrial groups, and other countries are performing the required R and D for advancement of FBC technology. The CAES/FBC will be reevaluated at a later date when FBC technology has matured and many of the concerns now plaguing FBC are resolved. (LCL)

  1. Preliminary design study of underground pumped hydro and compressed-air energy storage in hard rock. Volume 9: Design approaches. CAES. Appendix B: Champagne effect

    NASA Astrophysics Data System (ADS)

    1981-04-01

    The significance of the release of dissolved air from the water in the water shaft during air compression on the design and operation of a hydrolically compensated CAES plant was investigated. This air release phenomena was named the Champagne Effect. Included is a description of the work to investigate the rate of diffusion of air into water, the rate of the subsequent release of air from the water during passage up the water shaft, and an evaluation of the resulting behavior of the air bubbles in the shaft. Also included is a discussion of dynamic modeling. Simulation was based upon a two fluid model of the PEPCO system and includes an analysis of potential modifications to the design that might further mitigate any operation problems.

  2. Preliminary design study of compressed-air energy storage in a salt dome. Volume 1: executive summary. Final report

    SciTech Connect

    Not Available

    1982-01-01

    The preliminary design and cost estimate of a compressed air energy storage (CAES) plant located in the Middle South Utilities (MSU) system are summarized in this report. The 220 MWe CAES plant which stores air in two solution mined salt caverns, is located at the Carmichael salt dome near Jackson, Mississippi. The facility criteria, site selection and the turbomachinery and auxiliaries, are briefly described together with an outline of the proposed procedure for developing the caverns. Using this information and data, the preliminary CAES plant design was prepared; also the capital cost estimate, cash flow and project schedule were developed. The Environmental Assessment did not reveal any major site impediments to the construction of the plant. However, it is believed that an EIS is required primarily because CAES is a new technology without precedent in the United States. Although a final system planning study was not completed because of lack of funds, from preliminary analysis a CAES plant does not appear to be economic in the MSU system before the mid 1990s. This is due to the unique features of the MSU system. For other systems under more favorable conditions, CAES may be economic at an earlier date. The construction of a CAES plant with salt cavern air storage may by considered ready for use as a commercial electric generating plant. The experience at the Huntorf plant in West Germany demonstrates the technical feasibility of the CAES concept. Certain details of the plant defined in this study are different from the Huntorf plant. Design verification by limited testing and analysis would provide added confidence to those considering a CAES plant.

  3. A one-dimensional numerical model for predicting pressure and velocity oscillations of a compressed air-pocket in a vertical shaft

    NASA Astrophysics Data System (ADS)

    Choi, Y.; Leon, A.; Apte, S.

    2015-12-01

    The presence of pressurized air pockets in combined sewer systems is argued to produce geyser flows, which is an oscillating jetting of a mixture of gas-liquid flows through vertical shafts. A 1D numerical model is developed for predicting pressure and velocity oscillations of a compressed air-pocket in a vertical shaft which in turn attempts to simulate geyser like flows. The vertical shaft is closed at the bottom and open to ambient pressure at the top. Initially, the lower section of the vertical shaft is filled with compressed air and the upper section with water. The interaction between the pressurized air pocket and the water column in the vertical shaft exhibits an oscillatory motion of the water column that decays over time. The model accounts for steady and unsteady friction to estimate the energy dissipation. The model also includes the falling flow of water around the external perimeter of the pressurized air pocket by assuming that any expansion in the pressurized air pocket would result in the falling volume of water. The acceleration of air-water interface is predicted through a force balance between the pressurized air pocket and the water column combined with the Method of Characteristics that resolves pressure and velocity within the water column. The expansion and compression of the pressurized air pocket is assumed to follow either isothermal process or adiabatic process. Results for both assumptions; isothermal and adiabatic processes, are presented. The performance of the developed 1D numerical model is compared with that of a commercial 3D CFD model. Overall, a good agreement between both models is obtained for pressure and velocity oscillations. The paper will also present a sensitivity analysis of the 3D CFD model.

  4. Organization of Microgels at the Air-Water Interface under Compression: Role of Electrostatics and Cross-Linking Density.

    PubMed

    Picard, Christine; Garrigue, Patrick; Tatry, Marie-Charlotte; Lapeyre, Véronique; Ravaine, Serge; Schmitt, Véronique; Ravaine, Valérie

    2017-08-15

    Poly(N-isopropylacrylamide) (pNIPAM) microgels are soft and deformable particles, which can adsorb at liquid interfaces. In the present paper, we study the two-dimensional organization of charged and quasi-neutral microgels with different cross-linking densities, under compression at the air-water interface and the transfer of the microgel monolayer onto a solid substrate at different surface pressures. At low cross-linking densities, the microgels form highly ordered hexagonal lattices on the solid substrate over large areas, with a unique lattice parameter that decreases continuously as the surface pressure increases. We thus prove that the microgel conformation evolves at the air-water interface. The microgels undergo a continuous transition from a highly flattened state at low surface coverage, where the maximal polymer segments are adsorbed at the interface, to entangled flattened microgels, and finally the thickening of the layer up to a dense hydrogel layer of compacted microgels. Moreover, two batches of microgels, with and without charges, are compared. The contribution of electrostatic interactions is assessed via changing the charge density of the microgels or modulating the Debye length. In both cases, electrostatics does not change the lattice parameter, meaning that, despite the microgel different swelling ratio, charges do not affect neither interactions between particles at the interface nor microgels adsorption. Conversely, the cross-linking density has a strong impact on microgel packing at the interface: increasing the cross-linking density strongly decreases the extent of microgel flattening and promotes the occurrence of coexisting hexagonally ordered domains with different lattice parameters.

  5. Assessment of air quality after the implementation of compressed natural gas (CNG) as fuel in public transport in Delhi, India.

    PubMed

    Ravindra, Khaiwal; Wauters, Eric; Tyagi, Sushil K; Mor, Suman; Van Grieken, René

    2006-04-01

    Public transport in Delhi was amended by the Supreme Court of India to use Compressed Natural Gas (CNG) instead of diesel or petrol. After the implementation of CNG since April 2001, Delhi has the highest fraction of CNG-run public vehicles in the world and most of them were introduced within 20 months. In the present study, the concentrations of various criteria air pollutants (SPM, PM(10), CO, SO(2) and NO(x)) and organic pollutants such as benzene, toluene, xylene (BTX) and polycyclic aromatic hydrocarbons (PAHs) were assessed before and after the implementation of CNG. A decreasing trend was found for PAHs, SO(2) and CO concentrations, while the NO(x) level was increased in comparison to those before the implementation of CNG. Further, SPM, PM(10), and BTX concentrations showed no significant change after the implementation of CNG. However, the BTX concentration demonstrated a clear relation with the benzene content of gasoline. In addition to the impact of the introduction of CNG the daily variation in PAHs levels was also studied and the PAHs concentrations were observed to be relatively high between 10 pm to 6 am, which gives a proof of a relation with the limited day entry and movement of heavy vehicles in Delhi.

  6. Humidity-dependent compression-induced glass transition of the air-water interfacial Langmuir films of poly(D,L-lactic acid-ran-glycolic acid) (PLGA).

    PubMed

    Kim, Hyun Chang; Lee, Hoyoung; Jung, Hyunjung; Choi, Yun Hwa; Meron, Mati; Lin, Binhua; Bang, Joona; Won, You-Yeon

    2015-07-28

    Constant rate compression isotherms of the air-water interfacial Langmuir films of poly(D,L-lactic acid-ran-glycolic acid) (PLGA) show a distinct feature of an exponential increase in surface pressure in the high surface polymer concentration regime. We have previously demonstrated that this abrupt increase in surface pressure is linked to the glass transition of the polymer film, but the detailed mechanism of this process is not fully understood. In order to obtain a molecular-level understanding of this behavior, we performed extensive characterizations of the surface mechanical, structural and rheological properties of Langmuir PLGA films at the air-water interface, using combined experimental techniques including the Langmuir film balance, X-ray reflectivity and double-wall-ring interfacial rheometry methods. We observed that the mechanical and structural responses of the Langmuir PLGA films are significantly dependent on the rate of film compression; the glass transition was induced in the PLGA film only at fast compression rates. Surprisingly, we found that this deformation rate dependence is also dependent on the humidity of the environment. With water acting as a plasticizer for the PLGA material, the diffusion of water molecules through the PLGA film seems to be the key factor in the determination of the glass transformation properties and thus the mechanical response of the PLGA film against lateral compression. Based on our combined results, we hypothesize the following mechanism for the compression-induced glass transformation of the Langmuir PLGA film; (1) initially, a humidified/non-glassy PLGA film is formed in the full surface-coverage region (where the surface pressure shows a plateau) during compression; (2) further compression leads to the collapse of the PLGA chains and the formation of new surfaces on the air side of the film, and this newly formed top layer of the PLGA film is transiently glassy in character because the water evaporation rate

  7. Development of a Next-Generation Membrane-Integrated Adsorption Processor for CO2 Removal and Compression for Closed-Loop Air Revitalization Systems

    NASA Technical Reports Server (NTRS)

    Mulloth, Lila; LeVan, Douglas

    2002-01-01

    The current CO2 removal technology of NASA is very energy intensive and contains many non-optimized subsystems. This paper discusses the concept of a next-generation, membrane integrated, adsorption processor for CO2 removal nd compression in closed-loop air revitalization systems. This processor will use many times less power than NASA's current CO2 removal technology and will be capable of maintaining a lower CO2 concentration in the cabin than that can be achieved by the existing CO2 removal systems. The compact, consolidated, configuration of gas dryer, CO2 separator, and CO2 compressor will allow continuous recycling of humid air in the cabin and supply of compressed CO2 to the reduction unit for oxygen recovery. The device has potential application to the International Space Station and future, long duration, transit, and planetary missions.

  8. Development of a Next-Generation Membrane-Integrated Adsorption Processor for CO2 Removal and Compression for Closed-Loop Air Revitalization Systems

    NASA Technical Reports Server (NTRS)

    Mulloth, Lila; LeVan, Douglas

    2002-01-01

    The current CO2 removal technology of NASA is very energy intensive and contains many non-optimized subsystems. This paper discusses the concept of a next-generation, membrane integrated, adsorption processor for CO2 removal nd compression in closed-loop air revitalization systems. This processor will use many times less power than NASA's current CO2 removal technology and will be capable of maintaining a lower CO2 concentration in the cabin than that can be achieved by the existing CO2 removal systems. The compact, consolidated, configuration of gas dryer, CO2 separator, and CO2 compressor will allow continuous recycling of humid air in the cabin and supply of compressed CO2 to the reduction unit for oxygen recovery. The device has potential application to the International Space Station and future, long duration, transit, and planetary missions.

  9. The start-up of a gas turbine engine using compressed air tangentially fed onto the blades of the basic turbine

    NASA Technical Reports Server (NTRS)

    Slobodyanyuk, L. K.; Dayneko, V. I.

    1983-01-01

    The use of compressed air was suggested to increase the reliability and motor lifetime of a gas turbine engine. Experiments were carried out and the results are shown in the form of the variation in circumferential force as a function of the entry angle of the working jet onto the turbine blade. The described start-up method is recommended for use with massive rotors.

  10. Preliminary design study of underground pumped hydro and compressed-air energy storage in hard rock. Volume 6: Site investigation: Shallow drilling

    NASA Astrophysics Data System (ADS)

    1981-04-01

    The work was undertaken to define the surficial geological conditions and the nature of the overburden and the bedrock at shallow depths as part of the field exploration program for underground pumped hydro (UPH) and compressed air energy storage (CAES) facility. Testing was performed on selected rock and soil samples to define the physical and mechanical properties of the subsurface material. Piezometers were installed on the site for long term monitoring of the groundwater.

  11. Operational procedure for computer program for design point characteristics of a compressed-air generator with through-flow combustor for V/STOL applications

    NASA Technical Reports Server (NTRS)

    Krebs, R. P.

    1971-01-01

    The computer program described in this report calculates the design-point characteristics of a compressed-air generator for use in V/STOL applications such as systems with a tip-turbine-driven lift fan. The program computes the dimensions and mass, as well as the thermodynamic performance of a model air generator configuration which involves a straight through-flow combustor. Physical and thermodynamic characteristics of the air generator components are also given. The program was written in FORTRAN IV language. Provision has been made so that the program will accept input values in either SI units or U.S. customary units. Each air generator design-point calculation requires about 1.5 seconds of 7094 computer time for execution.

  12. Development of a Low-Power CO2 Removal and Compression System for Closed-Loop Air Revitalization in Future Spacecraft

    NASA Technical Reports Server (NTRS)

    Mulloth, Lila M.; Rosen, Micha; Affleck, David; LeVan, M. Douglas; Moate, Joe R.

    2005-01-01

    The current CO2 removal technology of NASA is very energy intensive and contains many non-optimized subsystems. This paper discusses the design and prototype development of a two-stage CO2 removal and compression system that will utilize much less power than NASA s current CO2 removal technology. This integrated system contains a Nafion membrane followed by a residual water adsorber that performs the function of the desiccant beds in the four-bed molecular sieve (4BMS) system of the International Space Station (ISS). The membrane and the water adsorber are followed by a two-stage CO2 removal and compression subsystem that satisfies the operations of the CO2 adsorbent beds of the 4BMS aid the interface compressor for the Sabatier reactor connection. The two-stage compressor will utilize the principles of temperature-swing adsorption (TSA) compression technology for CO2 removal and compression. The similarities in operation and cycle times of the CO2 removal (first stage) and compression (second stage) operations will allow thermal coupling of the processes to maximize the efficiency of the system. In addition to the low-power advantage, this processor will maintain a lower CO2 concentration in the cabin than that can be achieved by the existing CO2 removal systems. The compact, consolidated, configuration of membrane gas dryer and CO2 separator and compressor will allow continuous recycling of humid air in the cabin and supply of compressed CO2 to the reduction unit for oxygen recovery. The device has potential application to the International Space Station and future, long duration, transit, and planetary missions.

  13. Development of a Low-Power CO2 Removal and Compression System for Closed-Loop Air Revitalization in Future Spacecraft

    NASA Technical Reports Server (NTRS)

    Mulloth, Lila M.; Rosen, Micha; Affleck, David; LeVan, M. Douglas; Moate, Joe R.

    2005-01-01

    The current CO2 removal technology of NASA is very energy intensive and contains many non-optimized subsystems. This paper discusses the design and prototype development of a two-stage CO2 removal and compression system that will utilize much less power than NASA s current CO2 removal technology. This integrated system contains a Nafion membrane followed by a residual water adsorber that performs the function of the desiccant beds in the four-bed molecular sieve (4BMS) system of the International Space Station (ISS). The membrane and the water adsorber are followed by a two-stage CO2 removal and compression subsystem that satisfies the operations of the CO2 adsorbent beds of the 4BMS aid the interface compressor for the Sabatier reactor connection. The two-stage compressor will utilize the principles of temperature-swing adsorption (TSA) compression technology for CO2 removal and compression. The similarities in operation and cycle times of the CO2 removal (first stage) and compression (second stage) operations will allow thermal coupling of the processes to maximize the efficiency of the system. In addition to the low-power advantage, this processor will maintain a lower CO2 concentration in the cabin than that can be achieved by the existing CO2 removal systems. The compact, consolidated, configuration of membrane gas dryer and CO2 separator and compressor will allow continuous recycling of humid air in the cabin and supply of compressed CO2 to the reduction unit for oxygen recovery. The device has potential application to the International Space Station and future, long duration, transit, and planetary missions.

  14. Infrared spectroscopy analysis of mixed DPPC/fibrinogen layer behavior at the air/liquid interface under a continuous compression-expansion condition.

    PubMed

    Yin, Chia-Lin; Chang, Chien-Hsiang

    2006-07-18

    The mixed layer behavior of dipalmitoyl phosphatidylcholine (DPPC) with fibrinogen at continuously compressed-expanded air/liquid interfaces was analyzed in situ by infrared reflection-absorption spectroscopy (IRRAS). The reflectance-absorbance (RA) intensities and/or wavenumbers of nu(a)-CH2 and amide I bands for a mixed DPPC/fibrinogen layer at the interface were obtained directly by an infrared spectrometer with a monolayer/grazing angle accessory and a removable Langmuir trough. The nu(a)-CH2 RA intensity-area hysteresis curves of a DPPC monolayer indicate a significant loss of free DPPC molecules at the interface during the first compression stage, which is also supported by the corresponding nu(a)-CH2 wavenumber-area hysteresis curves. For a mixed DPPC/fibrinogen layer at the interface, the amide I RA intensity-area hysteresis curves suggest that the fibrinogen molecules were expelled from the interface upon compression, apparently because of the presence of insoluble DPPC molecules. The squeeze-out of fibrinogen evidently removed a pronounced amount of DPPC from the interface, as judged from the corresponding nu(a)-CH2 intensity and wavenumber data. Moreover, significant adsorption of fibrinogen was found during the subsequent interface expansion stage. With the in situ IRRAS analysis of the mixed layer behavior at the interface, the induced loss of DPPC by fibrinogen expulsion from the compressed interface and the dominant adsorption of fibrinogen to the expanded interface were clearly demonstrated.

  15. PM-IRRAS assessment of the compression-mediated orientation of the nanocavity of a monoacylated beta-cyclodextrin in monolayers at the air-water interface.

    PubMed

    Vico, Raquel V; de Rossi, Rita H; Maggio, Bruno

    2010-06-01

    The structural orientation adopted along the compression-decompression isotherm by a monoacylated beta-cyclodextrin (C16-betaCD) at the air-water interface was assessed by polarization-modulation infrared reflection-adsorption spectroscopy (PM-IRRAS). The adoption of different orientations of the cyclic oligosaccharide unit, relative to the interfacial plane, was interpreted analyzing the PM-IRRAS band intensity ratios of specific vibrations corresponding to the cyclodextrin moiety as a function of the surface pressure for successive compression/decompression cycles. The spectroscopic analysis revealed that the cyclic oligosaccharide modifies its position under compression from one in which the plane of the cavity of the monoacylated beta-cyclodextrin lies almost parallel to the interface to another in which the plane of the cavity is perpendicular to the interface. Through the PM-IRRAS analysis, it was also possible to evidence the establishment of an intermolecular hydrogen bonding network that may play an important role in the dynamic properties of the monolayer packing. The hydrogen bonding network becomes more important with the increases of surface pressure, up to a molecular packing limit, and it imparts the surface properties of the film for future compression-decompression cycles.

  16. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  17. Air-guided photonic-crystal-fiber pulse-compression delivery of multimegawatt femtosecond laser output for nonlinear-optical imaging and neurosurgery

    NASA Astrophysics Data System (ADS)

    Lanin, Aleksandr A.; Fedotov, Il'ya V.; Sidorov-Biryukov, Dmitrii A.; Doronina-Amitonova, Lyubov V.; Ivashkina, Olga I.; Zots, Marina A.; Sun, Chi-Kuang; Ömer Ilday, F.; Fedotov, Andrei B.; Anokhin, Konstantin V.; Zheltikov, Aleksei M.

    2012-03-01

    Large-core hollow photonic-crystal fibers (PCFs) are shown to enable a fiber-format air-guided delivery of ultrashort infrared laser pulses for neurosurgery and nonlinear-optical imaging. With an appropriate dispersion precompensation, an anomalously dispersive 15-μm-core hollow PCF compresses 510-fs, 1070-nm light pulses to a pulse width of about 110 fs, providing a peak power in excess of 5 MW. The compressed PCF output is employed to induce a local photodisruption of corpus callosum tissues in mouse brain and is used to generate the third harmonic in brain tissues, which is captured by the PCF and delivered to a detector through the PCF cladding.

  18. Compressed air blast injury with palpebral, orbital, facial, cervical, and mediastinal emphysema through an eyelid laceration: a case report and review of literature

    PubMed Central

    2013-01-01

    Background To the best of our knowledge, only 14 cases of orbital or periorbital compressed air injuries from air guns or hoses have been reported in the literature. Case presentation A 30-year-old man was accidentally injured when a compressed air hose nozzle hit his right eye. The right half of his face was markedly swollen and a skin laceration near the right medial canthus was identified. A computed tomography scan showed subcutaneous and intraorbital emphysema around the right eye as well as cervical and mediastinal emphysema. He was prophylactically treated with systemic and topical antibiotics to prevent infection. All emphysemas had completely resolved 2 weeks after the injury. Conclusions A review of all 15 cases (including ours) showed that all patients were male and that 6 of the 15 (40.0%) cases were related to industrial accidents. Although emphysema was restricted to the subconjunctival space in 2 (13.3%) cases, it spread to the orbit in the remaining 13 (86.7%) cases. Cervical and mediastinal emphysemas were found in 3 (20.0%) cases, and intracranial emphysema was confirmed in 6 (40.0%) cases. Prophylactic antibiotics were used in most cases and the prognosis was generally good in all but one patient, who developed optic atrophy and blindness. PMID:24195485

  19. International Conference on Underground Pumped Hydro and Compressed Air Energy Storage, San Francisco, CA, September 20-22, 1982, Collection of Technical Papers

    NASA Astrophysics Data System (ADS)

    1982-08-01

    Topics discussed include an assessment of the market potential of compressed air energy storage (CAES) systems, turbocompressor considerations in CAES plants, subsurface geological considerations in siting an underground pumped hydro (UPH) project, and the preliminary assessment of waste heat recovery system for CAES plants. Also considered are CAES caverns design for leakage, simulation of the champagne effect in CAES plants, design of wells and piping for an aquifer CAES plant, various aspects of the Huntor CAES facility, low-pressure CAES, subsurface instrumentation plan for the Pittsfield CAES field test facility, and the feasibility of UPH storage in the Netherlands.

  20. Preliminary design study of compressed-air energy storage in a salt dome. Volume 4. CAES turbomachinery design

    NASA Astrophysics Data System (ADS)

    Zaugg, P.

    1982-06-01

    The question of whether it would be possible to build an air storage generating plant capable of operating economically and using leached out salt domes as air reservoirs was investigated. All the previous reports, most of which have been revised to a large extent, are included.

  1. Compression-shear-induced tilt azimuthal orientation of amphiphilic monolayers at the air-water interface: A C∞→C2v transition in the flow of a two-dimensional hexatic structure

    NASA Astrophysics Data System (ADS)

    Iwamoto, Mitsumasa; Tojima, Atsushi; Manaka, Takaaki; Zhong-Can, Ou-Yang

    2003-04-01

    Compression-shear-induced tilt azimuthal orientation of amphiphilic monolayer in tilting phases (L2 and L'2) at the air-water interface is analyzed as dynamical equilibrium of the elastic distortion of orthogonally hexagonal structure of the molecules under compression-induced shear flow. It is shown theoretically that the compression can induce molecular tilts lying along and/or against the flow direction. All these tilts makeup the initial random tilt azimuth of the molecular tails along a uniform direction. At a threshold compression speed, it causes a C∞→C2v-symmetry transition at the air-water interface. With Maxwell displacement current and optical second-harmonic generation measurements, the above theoretical results are verified experimentally in a monolayer of 4-heptyloxy-4'-cyanobiphenyl.

  2. Data Compression.

    ERIC Educational Resources Information Center

    Bookstein, Abraham; Storer, James A.

    1992-01-01

    Introduces this issue, which contains papers from the 1991 Data Compression Conference, and defines data compression. The two primary functions of data compression are described, i.e., storage and communications; types of data using compression technology are discussed; compression methods are explained; and current areas of research are…

  3. Techno-economic assessment of the need for bulk energy storage in low-carbon electricity systems with a focus on compressed air storage (CAES)

    NASA Astrophysics Data System (ADS)

    Safaei Mohamadabadi, Hossein

    Increasing electrification of the economy while decarbonizing the electricity supply is among the most effective strategies for cutting greenhouse gas (GHG) emissions in order to abate climate change. This thesis offers insights into the role of bulk energy storage (BES) systems to cut GHG emissions from the electricity sector. Wind and solar energies can supply large volumes of low-carbon electricity. Nevertheless, large penetration of these resources poses serious reliability concerns to the grid, mainly because of their intermittency. This thesis evaluates the performance of BES systems - especially compressed air energy storage (CAES) technology - for integration of wind energy from engineering and economic aspects. Analytical thermodynamic analysis of Distributed CAES (D-CAES) and Adiabatic CAES (A-CAES) suggest high roundtrip storage efficiencies ( 80% and 70%) compared to conventional CAES ( 50%). Using hydrogen to fuel CAES plants - instead of natural gas - yields a low overall efficiency ( 35%), despite its negligible GHG emissions. The techno-economic study of D-CAES shows that exporting compression heat to low-temperature loads (e.g. space heating) can enhance both the economic and emissions performance of compressed air storage plants. A case study for Alberta, Canada reveals that the abatement cost of replacing a conventional CAES with D-CAES plant practicing electricity arbitrage can be negative (-$40 per tCO2e, when the heat load is 50 km away from the air storage site). A green-field simulation finds that reducing the capital cost of BES - even drastically below current levels - does not substantially impact the cost of low-carbon electricity. At a 70% reduction in the GHG emissions intensity of the grid, gas turbines remain three times more cost-efficient in managing the wind variability compared to BES (in the best case and with a 15-minute resolution). Wind and solar thus, do not need to wait for availability of cheap BES systems to cost

  4. Heat Power Determination of Dv-290 Refrigerator's Evaporator on the Basis of Thermodynamic Parameters of Inlet Air / Określenie Mocy Cieplnej Parownika Chłodziarki Dv-290 Na Podstawie Parametrów Termodynamicznych Powietrza Wlotowego

    NASA Astrophysics Data System (ADS)

    Nowak, Bernard; Kuczera, Zbigniew

    2012-12-01

    The present paper introduces a method for calculating the thermal power of DV-290 mining air cooler's evaporator. The power usually differs from the nominal power given by the manufacturer. The thermodynamic parameters of cooled air are not obtained as a result of in situ measurements, but in indirect manner that is by determining the evaporation and condensation's pressure values of R407C refrigerant. The pressure dependencies formulated as a function of air enthalpy at the evaporator's inlet were obtained using calculations of a computer program which solves the system of equations describing heat and mass transfer in the refrigerator's compressor on the basis of previous measurements of air performed before and after its cooling. The obtained dependencies are demonstrated in a graphical (fig. 2 and fig. 3) and analytical (the regression equations (19) and (20)) manner, the values of correlation coefficients are also presented. For the known evaporation and condensation pressure values of the refrigerant, and thus for its basic physical parameters the complete thermal power of the evaporator was determined, that is its: air cooling overt power, dehumidification occult power, temperature, relative humidity and specific humidity of air after its cooling. In addition, using the mentioned method, the capacity of DV-290 refrigerator's evaporator is provided for the given thermodynamic parameters of air before cooling, along with air thermodynamic parameters after cooling.

  5. Performance evaluation of vapor-compression air conditioners in contemporary research houses. Topical report, June 1987-September 1988

    SciTech Connect

    Trehan, A.K.; Fortmann, R.C.; Nagda, N.L.

    1991-06-01

    Under the sponsorship of the Gas Research Institute, a high-efficiency electric air conditioner was tested at two unoccupied contemporary research houses in the Washington, D.C. area during two summer seasons. The research houses were moderately furnished to approximate conditions of occupancy for a family of three. Presence of occupants and use of appliances were simulated. Window openings were also simulated to increase latent load on the air conditioner. Performance of the air conditioner was characterized on the basis of indoor comfort, dynamic response to changing indoor/outdoor conditions, energy consumption, and efficiency. Such characterization will provide a basis for comparison with new or prototypical systems to be tested during subsequent cooling seasons.

  6. Liquid-Air Breathing Apparatus

    NASA Technical Reports Server (NTRS)

    Mills, Robert D.

    1990-01-01

    Compact unit supplies air longer than compressed-air unit. Emergency breathing apparatus stores air as cryogenic liquid instead of usual compressed gas. Intended for firefighting or rescue operations becoming necessary during planned potentially hazardous procedures.

  7. Free compression tube. Applications

    NASA Astrophysics Data System (ADS)

    Rusu, Ioan

    2012-11-01

    During the flight of vehicles, their propulsion energy must overcome gravity, to ensure the displacement of air masses on vehicle trajectory, to cover both energy losses from the friction between a solid surface and the air and also the kinetic energy of reflected air masses due to the impact with the flying vehicle. The flight optimization by increasing speed and reducing fuel consumption has directed research in the aerodynamics field. The flying vehicles shapes obtained through studies in the wind tunnel provide the optimization of the impact with the air masses and the airflow along the vehicle. By energy balance studies for vehicles in flight, the author Ioan Rusu directed his research in reducing the energy lost at vehicle impact with air masses. In this respect as compared to classical solutions for building flight vehicles aerodynamic surfaces which reduce the impact and friction with air masses, Ioan Rusu has invented a device which he named free compression tube for rockets, registered with the State Office for Inventions and Trademarks of Romania, OSIM, deposit f 2011 0352. Mounted in front of flight vehicles it eliminates significantly the impact and friction of air masses with the vehicle solid. The air masses come into contact with the air inside the free compression tube and the air-solid friction is eliminated and replaced by air to air friction.

  8. The Compressibility Burble

    NASA Technical Reports Server (NTRS)

    Stack, John

    1935-01-01

    Simultaneous air-flow photographs and pressure-distribution measurements have been made of the NACA 4412 airfoil at high speeds in order to determine the physical nature of the compressibility burble. The flow photographs were obtained by the Schlieren method and the pressures were simultaneously measured for 54 stations on the 5-inch-chord wing by means of a multiple-tube photographic manometer. Pressure-measurement results and typical Schlieren photographs are presented. The general nature of the phenomenon called the "compressibility burble" is shown by these experiments. The source of the increased drag is the compression shock that occurs, the excess drag being due to the conversion of a considerable amount of the air-stream kinetic energy into heat at the compression shock.

  9. Cost benefit analysis and energy savings of using compression and absorption chillers for air conditioners in hot and humid climates

    NASA Astrophysics Data System (ADS)

    Shekarchian, M.; Moghavvemi, M.; Motasemi, F.; Mahlia, T. M. I.

    2012-06-01

    The electricity consumption growth has increased steadily in the recent decade which is a great concern for the environment. Increasing the number of high-rise air-conditioned buildings and the rapid use of electrical appliances in residential and commercial sectors are two important factors for high electricity consumption. This paper investigates the annual energy required for cooling per unit area and the total energy cost per unit area for each type of air conditioning systems in hot and humid climates. The effects of changing the coefficient of performance (COP) of absorption chillers on cost saving was also investigated in this study. The results showed that using absorption chillers for cooling will increase the amount of energy consumption per unit area; however the energy cost per unit area will decrease. In addition this research indicates that for each 0.1 increment in COP of absorption chillers, there is about 500 USD/m2 saved cost.

  10. Preliminary design study of compressed-air energy storage in a salt dome. Volume 3. Design of the air-storage cavern in salt. Final report

    SciTech Connect

    Not Available

    1982-04-01

    This report was prepared as a result of a contract between Middle South Services, Inc. and Fenix and Scisson, Inc. The conceptual design was prepared for two sites, Hazlehurst and Prothro as two known possible sites. It was later expanded to include a third site, Carmichael as the first two sites were not then available. This required the design and costing at various depths, 670 m (2200 ft), 488 m (1600 ft) and 1067 m (3500 ft) to the top of the cavern. It also involves variation in the size of the caverns for various weekly cycles of required air pressure to supply the turbine during peak load periods. The air is released from the caverns at 310 Kg/sec for eight hours per day, five days per week and the caverns replenished through compressors eight hours per day seven days per week. The pressure ranges from a maximum of 70 bars at the beginning of the week to 50 bars at the end of the generating period on Friday. The temperature of the input and outlet air is assumed to be 140/sup 0/C. This agrees with the estimated temperature of the cavern at Carmichael which allows for an isothermal operation. During preparation of the report no technical or environmental barriers were found.

  11. Compressed air energy storage: preliminary design and site development program in an aquifer. Final draft, Task 2: Volume 2 of 3. Characterize and explore potential sites and prepare research and development plan

    SciTech Connect

    1980-12-01

    The characteristics of sites in Indiana and Illinois which are being investigated as potential sites for compressed air energy storage power plants are documented. These characteristics include geological considerations, economic factors, and environmental considerations. Extensive data are presented for 14 specific sites and a relative rating on the desirability of each site is derived. (LCL)

  12. KEY COMPARISON: Final report on the CIPM key comparisons for compressed air and nitrogen conducted in November 2004/June 2005: CCM.FF-5.b

    NASA Astrophysics Data System (ADS)

    Dopheide, Dietrich

    2006-01-01

    The calibration of gas meters for flow rate measurements of natural gas at high pressure is of critical importance for gas importers, gas distributors and international trade. It is recommended to calibrate gas meters actually with natural gas at high pressure; however, some countries apply compressed air or nitrogen as a surrogate fluid. Key comparisons (KCs) have been organized among all national metrology organizations (NMIs) worldwide that maintain national standards and take care of compressed air/nitrogen flow metrology. It turned out that, for the time being, only four NMIs were ready to participate, as no other NMIs or countries maintain national standards. These four NMIs are LNE in Paris, NEL in Great Britain, CMS/ITRI in Chinese Taipei, and KRISS in Korea. PTB-pigsar in Germany has been used as the pilot lab for the initial calibration of the transfer standard. All existing facilities in the world were invited to participate, but they all refrained from participation, as they are not yet ready, e.g. CEESI, SwRI, NIST. Russia does not maintain a calibration facility for this type of fluid flow so far. For more details we refer to the full report. The KC for compressed air was conducted during November 2004/June 2005 successfully at flow rates over a wide overlapping range of flow rate and pressure using a set of turbine meters. The transfer package comprises of two turbine meters put in series. Flow rates between 65 m3/h and 1000 m3/h and pressures between 5 bar and 40 bar have been applied. It shall be mentioned here that the weighted average for the KCRV according to a BIPM recommendation for KCs has been used as the first choice. The final report presents the degree of equivalence among the participants as well as the degree of equivalence to the KCRV and confirms all claimed uncertainties of the national calibration facilities of France, Great Britain, Korea and Chinese Taipei. In addition, a link to CCM.FF-K5a for natural gas can be made

  13. DNABIT Compress - Genome compression algorithm.

    PubMed

    Rajarajeswari, Pothuraju; Apparao, Allam

    2011-01-22

    Data compression is concerned with how information is organized in data. Efficient storage means removal of redundancy from the data being stored in the DNA molecule. Data compression algorithms remove redundancy and are used to understand biologically important molecules. We present a compression algorithm, "DNABIT Compress" for DNA sequences based on a novel algorithm of assigning binary bits for smaller segments of DNA bases to compress both repetitive and non repetitive DNA sequence. Our proposed algorithm achieves the best compression ratio for DNA sequences for larger genome. Significantly better compression results show that "DNABIT Compress" algorithm is the best among the remaining compression algorithms. While achieving the best compression ratios for DNA sequences (Genomes),our new DNABIT Compress algorithm significantly improves the running time of all previous DNA compression programs. Assigning binary bits (Unique BIT CODE) for (Exact Repeats, Reverse Repeats) fragments of DNA sequence is also a unique concept introduced in this algorithm for the first time in DNA compression. This proposed new algorithm could achieve the best compression ratio as much as 1.58 bits/bases where the existing best methods could not achieve a ratio less than 1.72 bits/bases.

  14. Preliminary design study of compressed-air energy storage in a salt dome. Volume 5. System, subsystem, and component design approach. Final report

    SciTech Connect

    Not Available

    1982-04-01

    The approach to system, subsystem, and component design for a compressed-air energy storage (CAES) plant located in the Middle South Services, Inc., is presented in this final report. The design approach is based on the facility design criteria described in Volume 2 and the site conditions at the Carmichael salt dome located near Jackson, Mississippi. For the selected weekly cycle, Brown Boveri Corporation selected a single-casing design of fired-high-power and fired-low-power turbines. The high-power (HP) turbine operates at inlet conditions of 609.2 psia (42 bar) and 1021.4/sup 0/F (550/sup 0/C), while the low-power (LP) turbine operates at 159.5 psia (11 bar) and 1633.4/sup 0/F (890/sup 0/C). A tubular design of exhaust gas recuperator heats the incoming air from the storage cavern from 138.4/sup 0/F (60/sup 0/C) to 692/sup 0/F (367/sup 0/C). The compressor design is a single-shaft, tandem-compound arrangement with a 3600-rpm LP compressor and a 6850-rpm HP compressor. The LP compressor is a combination six-stage axial, three-stage radial compressor with an integral cooler and diffuser built into the casing. The HP compressor is a five-stage radial compressor with external intercooler provided after both the second and fourth stages. Fenix and Scisson, Inc., selected two half-size air storage caverns, each capable of delivering full-turbine air mass flow. A solutioning rate of 1750 gpm will allow completion of both caverns without prolonging construction schedule. Fuel is No. 2 distillate, which is delivered on a weekly basis. Rather than construct a rail siding to the plant, a trade-off study showed it more economical to pump the fuel oil to the CAES plant through a seven-mile buried pipeline from the nearest existing rail line. The exhaust gas recuperator, synchronous clutches, and gear case between the HP and LP compressors are key components which require special attention in design and fabrication to ensure reliable CAES plant operation.

  15. Preliminary design study of underground pumped hydro and compressed-air energy storage in hard rock. Volume 4: System planning studies

    NASA Astrophysics Data System (ADS)

    1981-04-01

    Preliminary design and planning studies of water compensated compressed air energy storage (CAES) and underground pumped hydroelectric (UPH) power plants are presented. The costs of the CAES and UPH plant designs, and the results of economic evaluations performed for the PEPCO system are presented. The PEPCO system planning analysis was performed in parallel stages with plant design development. Analyses performed early in the project indicated a requirement for 1000 MW/10,000 MWH of energy storage on a daily operating schedule, with economic installation in two segments of 500 MW in 1990 and 1997. The analysis was updated eighteen months later near the end of the project to reflect the impact of new growth projections and revised plant costs. The revised results indicated economic installations for either UPH or CAES of approximately 675 MW/6750 MWH on a daily cycle, installed in blocks of approximately 225 MW in 1990, 1993 and 1995. Significant savings in revenue requirements and oil fuel over the combustion turbine alternative were identified for both CAES and UPH.

  16. Lessons from Iowa : development of a 270 megawatt compressed air energy storage project in midwest Independent System Operator : a study for the DOE Energy Storage Systems Program.

    SciTech Connect

    Holst, Kent; Huff, Georgianne; Schulte, Robert H.; Critelli, Nicholas

    2012-01-01

    The Iowa Stored Energy Park was an innovative, 270 Megawatt, $400 million compressed air energy storage (CAES) project proposed for in-service near Des Moines, Iowa, in 2015. After eight years in development the project was terminated because of site geological limitations. However, much was learned in the development process regarding what it takes to do a utility-scale, bulk energy storage facility and coordinate it with regional renewable wind energy resources in an Independent System Operator (ISO) marketplace. Lessons include the costs and long-term economics of a CAES facility compared to conventional natural gas-fired generation alternatives; market, legislative, and contract issues related to enabling energy storage in an ISO market; the importance of due diligence in project management; and community relations and marketing for siting of large energy projects. Although many of the lessons relate to CAES applications in particular, most of the lessons learned are independent of site location or geology, or even the particular energy storage technology involved.

  17. Stabilization of phospholipid multilayers at the air-water interface by compression beyond the collapse: a BAM, PM-IRRAS, and molecular dynamics study.

    PubMed

    Saccani, J; Castano, S; Beaurain, F; Laguerre, M; Desbat, B

    2004-10-12

    Compression beyond the collapse of phospholipid monolayers on a modified Langmuir trough has revealed the formation of stable multilayers at the air-water interface. Those systems are relevant new models for studying the properties of biological membranes and for understanding the nature of interactions between membranes and peptides or proteins. The collapse of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-di[cis-9-octadecenoyl]-sn-glycero-3-[phospho-l-serine] (DOPS), 1,2-di[cis-9-octadecenoyl]-sn-glycero-3-phosphocholine (DOPC), and 1,2-di[cis-9-octadecenoyl]-sn-glycero-3-[phospho-1-rac-glycerol] (DOPG) monolayers has been investigated by isotherm measurements, Brewster angle microscopy (BAM), and polarization modulation infrared reflection-absorption spectroscopy (PM-IRRAS). In the cases of DMPC and DOPS, the collapse of the monolayers revealed the formation of bilayer and trilayer structures, respectively. The DMPC bilayer stability has been analyzed also by a molecular dynamics study. The collapse of the DOPC and DOPG systems shows a different behavior, and the Brewster angle microscopy reveals the formation of luminous bundles, which can be interpreted as diving multilayers in the subphase.

  18. Doppler ultrasound surveillance in deep tunneling compressed-air work with Trimix breathing: bounce dive technique compared to saturation-excursion technique.

    PubMed

    Vellinga, T P van Rees; Sterk, W; de Boer, A G E M; van der Beek, A J; Verhoeven, A C; van Dijk, F J H

    2008-01-01

    The Western Scheldt Tunneling Project in The Netherlands provided a unique opportunity to evaluate two deep-diving techniques with Doppler ultrasound surveillance. Divers used the bounce diving techniques for repair and maintenance of the TBM. The tunnel boring machine jammed at its deepest depth. As a result the work time was not sufficient. The saturation diving technique was developed and permitted longer work time at great depth. Thirty-one divers were involved in this project. Twenty-three divers were examined using Doppler ultrasound. Data analysis addressed 52 exposures to Trimix at 4.6-4.8 bar gauge using the bounce technique and 354 exposures to Trimix at 4.0-6.9 bar gauge on saturation excursions. No decompression incidents occurred with either technique during the described phase of the project. Doppler ultrasound revealed that the bubble loads assessed in both techniques were generally low. We find out, that despite longer working hours, shorter decompression times and larger physical workloads, the saturation-excursion technique was associated with significant lower bubble grades than in the bounce technique using Doppler Ultrasound. We conclude that the saturation-excursion technique with Trimix is a good option for deep and long exposures in caisson work. The Doppler technique proved valuable, and it should be incorporated in future compressed-air work.

  19. Preliminary design study of underground pumped hydro and compressed-air energy storage in hard rock. Volume 1. Executive summary. Final report

    SciTech Connect

    Not Available

    1981-05-01

    Potomac Electric Power Company (PEPCO) and Acres American Incorporated (AAI) have carried out a preliminary design study of water-compensated Compressed Air Energy Storage (CAES) and Underground Pumped Hydroelectric (UPH) plants for siting in geological conditions suitable for hard rock excavations. The work was carried out over a period of three years and was sponsored by the US Department of Energy (DOE), the Electric Power Research Institute (EPRI) and PEPCO. The study was divided into five primary tasks as follows: establishment of design criteria and analysis of impact on power system; selection of site and establishment of site characteristics; formulation of design approaches; assessment of environmental and safety aspects; and preparation of preliminary design of plant. The salient aspects considered and the conclusions reached during the consideration of the five primary tasks for both CAES and UPH are presented in this Executive Summary, which forms Volume 1 of the series of reports prepared during the study. The investigations and analyses carried out, together with the results and conclusions reached, are described in detail in Volumes 2 through 13 and ten appendices.

  20. Coal-fuelled systems for peaking power with 100% CO2 capture through integration of solid oxide fuel cells with compressed air energy storage

    NASA Astrophysics Data System (ADS)

    Nease, Jake; Adams, Thomas A.

    2014-04-01

    In this study, a coal-fuelled integrated solid oxide fuel cell (SOFC) and compressed air energy storage (CAES) system in a load-following power production scenario is discussed. Sixteen SOFC-based plants with optional carbon capture and sequestration (CCS) and syngas shifting steps are simulated and compared to a state-of-the-art supercritical pulverised coal (SCPC) plant. Simulations are performed using a combination of MATLAB and Aspen Plus v7.3. It was found that adding CAES to a SOFC-based plant can provide load-following capabilities with relatively small effects on efficiencies (1-2% HHV depending on the system configuration) and levelized costs of electricity (∼0.35 ¢ kW-1 h-1). The load-following capabilities, as measured by least-squares metrics, show that this system may utilize coal and achieve excellent load-tracking that is not adversely affected by the inclusion of CCS. Adding CCS to the SOFC/CAES system reduces measurable direct CO2 emission to zero. A seasonal partial plant shutdown schedule is found to reduce fuel consumption by 9.5% while allowing for cleaning and maintenance windows for the SOFC stacks without significantly affecting the performance of the system (∼1% HHV reduction in efficiency). The SOFC-based systems with CCS are found to become economically attractive relative to SCPC above carbon taxes of 22 ton-1.

  1. Energy efficiency improvements in Chinese compressed airsystems

    SciTech Connect

    McKane, Aimee; Li, Li; Li, Yuqi; Taranto, T.

    2007-06-01

    Industrial compressed air systems use more than 9 percent ofall electricity used in China. Experience in China and elsewhere hasshown that these systems can be much more energy efficient when viewed asa whole system and rather than as isolated components.This paper presentsa summary and analysis of several compressed air system assessments.Through these assessments, typical compressed air management practices inChina are analyzed. Recommendations are made concerning immediate actionsthat China s enterprises can make to improve compressed air systemefficiency using best available technology and managementstrategies.

  2. Compression embedding

    DOEpatents

    Sandford, II, Maxwell T.; Handel, Theodore G.; Bradley, Jonathan N.

    1998-01-01

    A method and apparatus for embedding auxiliary information into the digital representation of host data created by a lossy compression technique and a method and apparatus for constructing auxiliary data from the correspondence between values in a digital key-pair table with integer index values existing in a representation of host data created by a lossy compression technique. The methods apply to data compressed with algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as ordered sequences of blocks containing integer indices having redundancy and uncertainty of value by one unit, allowing indices which are adjacent in value to be manipulated to encode auxiliary data. Also included is a method to improve the efficiency of lossy compression algorithms by embedding white noise into the integer indices. Lossy compression methods use loss-less compression to reduce to the final size the intermediate representation as indices. The efficiency of the loss-less compression, known also as entropy coding compression, is increased by manipulating the indices at the intermediate stage. Manipulation of the intermediate representation improves lossy compression performance by 1 to 10%.

  3. Compression embedding

    DOEpatents

    Sandford, M.T. II; Handel, T.G.; Bradley, J.N.

    1998-07-07

    A method and apparatus for embedding auxiliary information into the digital representation of host data created by a lossy compression technique and a method and apparatus for constructing auxiliary data from the correspondence between values in a digital key-pair table with integer index values existing in a representation of host data created by a lossy compression technique are disclosed. The methods apply to data compressed with algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as ordered sequences of blocks containing integer indices having redundancy and uncertainty of value by one unit, allowing indices which are adjacent in value to be manipulated to encode auxiliary data. Also included is a method to improve the efficiency of lossy compression algorithms by embedding white noise into the integer indices. Lossy compression methods use loss-less compression to reduce to the final size the intermediate representation as indices. The efficiency of the loss-less compression, known also as entropy coding compression, is increased by manipulating the indices at the intermediate stage. Manipulation of the intermediate representation improves lossy compression performance by 1 to 10%. 21 figs.

  4. Compression embedding

    DOEpatents

    Sandford, M.T. II; Handel, T.G.; Bradley, J.N.

    1998-03-10

    A method of embedding auxiliary information into the digital representation of host data created by a lossy compression technique is disclosed. The method applies to data compressed with lossy algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as integer indices having redundancy and uncertainty in value by one unit. Indices which are adjacent in value are manipulated to encode auxiliary data. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user. Lossy compression methods use loss-less compressions known also as entropy coding, to reduce to the final size the intermediate representation as indices. The efficiency of the compression entropy coding, known also as entropy coding is increased by manipulating the indices at the intermediate stage in the manner taught by the method. 11 figs.

  5. Compression embedding

    DOEpatents

    Sandford, II, Maxwell T.; Handel, Theodore G.; Bradley, Jonathan N.

    1998-01-01

    A method of embedding auxiliary information into the digital representation of host data created by a lossy compression technique. The method applies to data compressed with lossy algorithms based on series expansion, quantization to a finite number of symbols, and entropy coding. Lossy compression methods represent the original data as integer indices having redundancy and uncertainty in value by one unit. Indices which are adjacent in value are manipulated to encode auxiliary data. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user. Lossy compression methods use loss-less compressions known also as entropy coding, to reduce to the final size the intermediate representation as indices. The efficiency of the compression entropy coding, known also as entropy coding is increased by manipulating the indices at the intermediate stage in the manner taught by the method.

  6. Geotechnical Feasibility Analysis of Compressed Air Energy Storage (CAES) in Bedded Salt Formations: a Case Study in Huai'an City, China

    NASA Astrophysics Data System (ADS)

    Zhang, Guimin; Li, Yinping; Daemen, Jaak J. K.; Yang, Chunhe; Wu, Yu; Zhang, Kai; Chen, Yanlong

    2015-09-01

    The lower reaches of the Yangtze River is one of the most developed regions in China. It is desirable to build compressed air energy storage (CAES) power plants in this area to ensure the safety, stability, and economic operation of the power network. Geotechnical feasibility analysis was carried out for CAES in impure bedded salt formations in Huai'an City, China, located in this region. First, geological investigation revealed that the salt groups in the Zhangxing Block meet the basic geological conditions for CAES storage, even though the possible unfavorable characteristics of the salt formations include bedding and different percentages of impurities. Second, mechanical tests were carried out to determine the mechanical characteristics of the bedded salt formations. It is encouraging that the samples did not fail even when they had undergone large creep deformation. Finally, numerical simulation was performed to evaluate the stability and volume shrinkage of the CAES under the following conditions: the shape of a single cavern is that of a pear; the width of the pillar is adopted as two times the largest diameter; three regular operating patterns were adopted for two operating caverns (internal pressure 9-10.5 MPa, 10-11.5 MPa, and 11-12.5 MPa), while the other two were kept at high pressure (internal pressure 10.5, 11.5, and 12.5 MPa) as backups; an emergency operating pattern in which two operating caverns were kept at atmospheric pressure (0.1 MPa) for emergency while the backups were under operation (9-10.5 MPa), simulated for 12 months at the beginning of the 5th year. The results of the analysis for the plastic zone, displacement, and volume shrinkage support the feasibility of the construction of an underground CAES power station.

  7. Compressive Holography

    NASA Astrophysics Data System (ADS)

    Lim, Se Hoon

    Compressive holography estimates images from incomplete data by using sparsity priors. Compressive holography combines digital holography and compressive sensing. Digital holography consists of computational image estimation from data captured by an electronic focal plane array. Compressive sensing enables accurate data reconstruction by prior knowledge on desired signal. Computational and optical co-design optimally supports compressive holography in the joint computational and optical domain. This dissertation explores two examples of compressive holography: estimation of 3D tomographic images from 2D data and estimation of images from under sampled apertures. Compressive holography achieves single shot holographic tomography using decompressive inference. In general, 3D image reconstruction suffers from underdetermined measurements with a 2D detector. Specifically, single shot holographic tomography shows the uniqueness problem in the axial direction because the inversion is ill-posed. Compressive sensing alleviates the ill-posed problem by enforcing some sparsity constraints. Holographic tomography is applied for video-rate microscopic imaging and diffuse object imaging. In diffuse object imaging, sparsity priors are not valid in coherent image basis due to speckle. So incoherent image estimation is designed to hold the sparsity in incoherent image basis by support of multiple speckle realizations. High pixel count holography achieves high resolution and wide field-of-view imaging. Coherent aperture synthesis can be one method to increase the aperture size of a detector. Scanning-based synthetic aperture confronts a multivariable global optimization problem due to time-space measurement errors. A hierarchical estimation strategy divides the global problem into multiple local problems with support of computational and optical co-design. Compressive sparse aperture holography can be another method. Compressive sparse sampling collects most of significant field

  8. Power plant including an exhaust gas recirculation system for injecting recirculated exhaust gases in the fuel and compressed air of a gas turbine engine

    DOEpatents

    Anand, Ashok Kumar; Nagarjuna Reddy, Thirumala Reddy; Shaffer, Jason Brian; York, William David

    2014-05-13

    A power plant is provided and includes a gas turbine engine having a combustor in which compressed gas and fuel are mixed and combusted, first and second supply lines respectively coupled to the combustor and respectively configured to supply the compressed gas and the fuel to the combustor and an exhaust gas recirculation (EGR) system to re-circulate exhaust gas produced by the gas turbine engine toward the combustor. The EGR system is coupled to the first and second supply lines and configured to combine first and second portions of the re-circulated exhaust gas with the compressed gas and the fuel at the first and second supply lines, respectively.

  9. 29 CFR 1910.169 - Air receivers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 5 2012-07-01 2012-07-01 false Air receivers. 1910.169 Section 1910.169 Labor Regulations... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Compressed Gas and Compressed Air Equipment § 1910.169 Air receivers. (a) General requirements—(1) Application. This section applies to compressed air receivers, and...

  10. 29 CFR 1910.169 - Air receivers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 5 2013-07-01 2013-07-01 false Air receivers. 1910.169 Section 1910.169 Labor Regulations... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Compressed Gas and Compressed Air Equipment § 1910.169 Air receivers. (a) General requirements—(1) Application. This section applies to compressed air receivers, and...

  11. 29 CFR 1910.169 - Air receivers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 5 2014-07-01 2014-07-01 false Air receivers. 1910.169 Section 1910.169 Labor Regulations... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Compressed Gas and Compressed Air Equipment § 1910.169 Air receivers. (a) General requirements—(1) Application. This section applies to compressed air receivers, and...

  12. 29 CFR 1910.169 - Air receivers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Air receivers. 1910.169 Section 1910.169 Labor Regulations... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Compressed Gas and Compressed Air Equipment § 1910.169 Air receivers. (a) General requirements—(1) Application. This section applies to compressed air receivers, and...

  13. 29 CFR 1910.169 - Air receivers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 5 2011-07-01 2011-07-01 false Air receivers. 1910.169 Section 1910.169 Labor Regulations... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Compressed Gas and Compressed Air Equipment § 1910.169 Air receivers. (a) General requirements—(1) Application. This section applies to compressed air receivers, and...

  14. Compressed gas fuel storage system

    DOEpatents

    Wozniak, John J.; Tiller, Dale B.; Wienhold, Paul D.; Hildebrand, Richard J.

    2001-01-01

    A compressed gas vehicle fuel storage system comprised of a plurality of compressed gas pressure cells supported by shock-absorbing foam positioned within a shape-conforming container. The container is dimensioned relative to the compressed gas pressure cells whereby a radial air gap surrounds each compressed gas pressure cell. The radial air gap allows pressure-induced expansion of the pressure cells without resulting in the application of pressure to adjacent pressure cells or physical pressure to the container. The pressure cells are interconnected by a gas control assembly including a thermally activated pressure relief device, a manual safety shut-off valve, and means for connecting the fuel storage system to a vehicle power source and a refueling adapter. The gas control assembly is enclosed by a protective cover attached to the container. The system is attached to the vehicle with straps to enable the chassis to deform as intended in a high-speed collision.

  15. Multi-kilowatt, all-fiber integrated chirped-pulse amplification system yielding 40x pulse compression using air-core fiber and conventional erbium-doped fiber amplifier.

    PubMed

    de Matos, C; Taylor, J

    2004-02-09

    We present a totally fiber integrated chirped-pulse amplification system using air-core photonic bandgap fiber and a conventional erbium-doped fiber amplifier. ~40-ps input pulses, generated in a Mach-Zehnder modulator, were stretched and spectrally broadened in a dispersion-shifted fiber before being amplified and subsequently compressed in 10 m of anomalously-dispersive photonic bandgap fiber to yield ~960 fs pulses. The system gives multi-kilowatt peak powers while the amplifier nonlinearity threshold is as low as ~150 W. Higher peak powers could be obtained by the use of an amplifier with higher nonlinearity threshold.

  16. Partial transparency of compressed wood

    NASA Astrophysics Data System (ADS)

    Sugimoto, Hiroyuki; Sugimori, Masatoshi

    2016-05-01

    We have developed novel wood composite with optical transparency at arbitrary region. Pores in wood cells have a great variation in size. These pores expand the light path in the sample, because the refractive indexes differ between constituents of cell and air in lumen. In this study, wood compressed to close to lumen had optical transparency. Because the condition of the compression of wood needs the plastic deformation, wood was impregnated phenolic resin. The optimal condition for high transmission is compression ratio above 0.7.

  17. Video Compression

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Optivision developed two PC-compatible boards and associated software under a Goddard Space Flight Center Small Business Innovation Research grant for NASA applications in areas such as telerobotics, telesciences and spaceborne experimentation. From this technology, the company used its own funds to develop commercial products, the OPTIVideo MPEG Encoder and Decoder, which are used for realtime video compression and decompression. They are used in commercial applications including interactive video databases and video transmission. The encoder converts video source material to a compressed digital form that can be stored or transmitted, and the decoder decompresses bit streams to provide high quality playback.

  18. Compression stockings

    MedlinePlus

    ... knee bend. Compression Stockings Can Be Hard to Put on If it's hard for you to put on the stockings, try these tips: Apply lotion ... your legs, but let it dry before you put on the stockings. Use a little baby powder ...

  19. Clean air program: Design guidelines for bus transit systems using compressed natural gas as an alternative fuel. Final report, July 1995-April 1996

    SciTech Connect

    Raj, P.K.; Hathaway, W.T.; Kangas, R.

    1996-06-01

    The guidelines document presents various facility and bus design issues that need to be considered to ensure safe operations when using CNG (Compressed Natural Gas) as the alternative fuel. Fueling facility, garaging facility, maintenance facility requirements and safety practices are indicated. Among the issues discussed are fuel properties, potential hazards, fuel requirements for specified level of service, applicable codes and standards, ventilation, and electrical classification. Critical fuel related safety issues in the design of the related systems on the bus are also discussed.

  20. Compressed convolution

    NASA Astrophysics Data System (ADS)

    Elsner, Franz; Wandelt, Benjamin D.

    2014-01-01

    We introduce the concept of compressed convolution, a technique to convolve a given data set with a large number of non-orthogonal kernels. In typical applications our technique drastically reduces the effective number of computations. The new method is applicable to convolutions with symmetric and asymmetric kernels and can be easily controlled for an optimal trade-off between speed and accuracy. It is based on linear compression of the collection of kernels into a small number of coefficients in an optimal eigenbasis. The final result can then be decompressed in constant time for each desired convolved output. The method is fully general and suitable for a wide variety of problems. We give explicit examples in the context of simulation challenges for upcoming multi-kilo-detector cosmic microwave background (CMB) missions. For a CMB experiment with detectors with similar beam properties, we demonstrate that the algorithm can decrease the costs of beam convolution by two to three orders of magnitude with negligible loss of accuracy. Likewise, it has the potential to allow the reduction of disk space required to store signal simulations by a similar amount. Applications in other areas of astrophysics and beyond are optimal searches for a large number of templates in noisy data, e.g. from a parametrized family of gravitational wave templates; or calculating convolutions with highly overcomplete wavelet dictionaries, e.g. in methods designed to uncover sparse signal representations.

  1. Numerical Analysis of Autoignition and Combustion of n-Butane and Air Mixture in Homogeneous-Charge Compression-Ignition Engine Using Elementary Reactions

    NASA Astrophysics Data System (ADS)

    Yamasaki, Yudai; Iida, Norimasa

    The present study focuses on clarifying the combustion mechanism of the homogeneous-charge compression-ignition (HCCI) engine in order to control ignition and combustion as well as to reduce HC and CO emissions and to maintain high combustion efficiency by calculating the chemical kinetics of elementary reactions. For the calculations, n-butane was selected as fuel since it is a fuel with the smallest carbon number in the alkane family that shows two-stage autoignition (heat release with low-temperature reaction (LTR) and with high-temperature reaction (HTR)) similarly to higher hydrocarbons such as gasoline. The CHEMKIN code was used for the calculations assuming zero dimensions in the combustion chamber and adiabatic change. The results reveal the heat release mechanism of the LTR and HTR, the control factor of ignition timing and combustion speed, and the condition need to reduce HC and CO emissions and to maintain high combustion efficiency.

  2. Computing interface motion in compressible gas dynamics

    NASA Technical Reports Server (NTRS)

    Mulder, W.; Osher, S.; Sethan, James A.

    1992-01-01

    An analysis is conducted of the coupling of Osher and Sethian's (1988) 'Hamilton-Jacobi' level set formulation of the equations of motion for propagating interfaces to a system of conservation laws for compressible gas dynamics, giving attention to both the conservative and nonconservative differencing of the level set function. The capabilities of the method are illustrated in view of the results of numerical convergence studies of the compressible Rayleigh-Taylor and Kelvin-Helmholtz instabilities for air-air and air-helium boundaries.

  3. Premixed autoignition in compressible turbulence

    NASA Astrophysics Data System (ADS)

    Konduri, Aditya; Kolla, Hemanth; Krisman, Alexander; Chen, Jacqueline

    2016-11-01

    Prediction of chemical ignition delay in an autoignition process is critical in combustion systems like compression ignition engines and gas turbines. Often, ignition delay times measured in simple homogeneous experiments or homogeneous calculations are not representative of actual autoignition processes in complex turbulent flows. This is due the presence of turbulent mixing which results in fluctuations in thermodynamic properties as well as chemical composition. In the present study the effect of fluctuations of thermodynamic variables on the ignition delay is quantified with direct numerical simulations of compressible isotropic turbulence. A premixed syngas-air mixture is used to remove the effects of inhomogeneity in the chemical composition. Preliminary results show a significant spatial variation in the ignition delay time. We analyze the topology of autoignition kernels and identify the influence of extreme events resulting from compressibility and intermittency. The dependence of ignition delay time on Reynolds and turbulent Mach numbers is also quantified. Supported by Basic Energy Sciences, Dept of Energy, United States.

  4. Friction of Compression-ignition Engines

    NASA Technical Reports Server (NTRS)

    Moore, Charles S; Collins, John H , Jr

    1936-01-01

    The cost in mean effective pressure of generating air flow in the combustion chambers of single-cylinder compression-ignition engines was determined for the prechamber and the displaced-piston types of combustion chamber. For each type a wide range of air-flow quantities, speeds, and boost pressures was investigated. Supplementary tests were made to determine the effect of lubricating-oil temperature, cooling-water temperature, and compression ratio on the friction mean effective pressure of the single-cylinder test engine. Friction curves are included for two 9-cylinder, radial, compression-ignition aircraft engines. The results indicate that generating the optimum forced air flow increased the motoring losses approximately 5 pounds per square inch mean effective pressure regardless of chamber type or engine speed. With a given type of chamber, the rate of increase in friction mean effective pressure with engine speed is independent of the air-flow speed. The effect of boost pressure on the friction cannot be predicted because the friction was decreased, unchanged, or increased depending on the combustion-chamber type and design details. High compression ratio accounts for approximately 5 pounds per square inch mean effective pressure of the friction of these single-cylinder compression-ignition engines. The single-cylinder test engines used in this investigation had a much higher friction mean effective pressure than conventional aircraft engines or than the 9-cylinder, radial, compression-ignition engines tested so that performance should be compared on an indicated basis.

  5. Turbulence in Compressible Flows

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Lecture notes for the AGARD Fluid Dynamics Panel (FDP) Special Course on 'Turbulence in Compressible Flows' have been assembled in this report. The following topics were covered: Compressible Turbulent Boundary Layers, Compressible Turbulent Free Shear Layers, Turbulent Combustion, DNS/LES and RANS Simulations of Compressible Turbulent Flows, and Case Studies of Applications of Turbulence Models in Aerospace.

  6. Turbulence in Compressible Flows

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Lecture notes for the AGARD Fluid Dynamics Panel (FDP) Special Course on 'Turbulence in Compressible Flows' have been assembled in this report. The following topics were covered: Compressible Turbulent Boundary Layers, Compressible Turbulent Free Shear Layers, Turbulent Combustion, DNS/LES and RANS Simulations of Compressible Turbulent Flows, and Case Studies of Applications of Turbulence Models in Aerospace.

  7. Generalized Charts for Determination of Pressure Drop of a High-speed Compressible Fluid in Heat-exchanger Passages I : Air Heated in Smooth Passages of Constant Area with Constant Wall Temperature

    NASA Technical Reports Server (NTRS)

    Valerino, Michael F

    1948-01-01

    In the present paper an analysis is made of the compressible-flow variations occurring in heat-exchanger passages. The results of the analysis describe the flow and heating characteristics for which specific flow passages can be treated as segments of generalized flow systems. The graphical representation of the flow variations in the generalized flow systems can then be utilized as working charts to determine directly the pressure changes occurring in any specific flow passage. On the basis of these results, working charts are constructed to handle the case of air heated at constant wall temperature under turbulent-flow conditions. A method is given of incorporating the effect on the heat-exchanger flow process of high temperature differential between passage wall and fluid as based on recent NACA experimental data. Good agreement is obtained between the experimental and the chart pressure-drop values for passage-wall average temperatures as high as 1752 degrees R (experimental limit) and for flow Mach numbers ranging from 0.32 to 1.00 (choke) at the passage exit.

  8. Compressed Gas Safety for Experimental Fusion Facilities

    SciTech Connect

    Lee C. Cadwallader

    2004-09-01

    Experimental fusion facilities present a variety of hazards to the operators and staff. There are unique or specialized hazards, including magnetic fields, cryogens, radio frequency emissions, and vacuum reservoirs. There are also more general industrial hazards, such as a wide variety of electrical power, pressurized air, and cooling water systems in use, there are crane and hoist loads, working at height, and handling compressed gas cylinders. This paper outlines the projectile hazard assoicated with compressed gas cylinders and mthods of treatment to provide for compressed gas safety. This information should be of interest to personnel at both magnetic and inertial fusion experiments.

  9. Two-dimensional symmetrical inlets with external compression

    NASA Technical Reports Server (NTRS)

    Ruden, P

    1950-01-01

    The purpose of inlets like, for instance, those of air-cooled radiators and scoops is to take a certain air quantity out of the free stream and to partly convert the free-stream velocity into pressure. In the extreme case this pressure conversion may occur either entirely in the interior of the inlet (inlet with internal compression) or entirely in the free stream ahead of the inlet (inlet with external compression). In this report a theory for two-dimensional inlets with external compression is developed and illustrated by numerical examples. Intermediary forms between inlets with internal and external compression which can be derived from the latter are briefly discussed.

  10. Air release control in seismic energy source air gun

    SciTech Connect

    Bays, M.G.

    1980-10-28

    Disclosed is a seismic source device, known in the industry as an air gun, having shuttle control for allowing a predetermined discharge of compressed air into water for purposes of seismic exploration. The shuttle is controlled by secondary shuttle means for closing the exhaust ports before all of the compressed air in the firing chamber of the air gun is exhausted. This point of closing the exhaust ports before virtually all of the compressed air is discharged differs from prior art air guns. By preventing further discharge of air, secondary pulses are greatly reduced, thereby enhancing the operation of the entire system. Further, by preventing all the air in the firing chamber from being discharged, the system becomes more efficient and more cost effective.

  11. Learning in compressed space.

    PubMed

    Fabisch, Alexander; Kassahun, Yohannes; Wöhrle, Hendrik; Kirchner, Frank

    2013-06-01

    We examine two methods which are used to deal with complex machine learning problems: compressed sensing and model compression. We discuss both methods in the context of feed-forward artificial neural networks and develop the backpropagation method in compressed parameter space. We further show that compressing the weights of a layer of a multilayer perceptron is equivalent to compressing the input of the layer. Based on this theoretical framework, we will use orthogonal functions and especially random projections for compression and perform experiments in supervised and reinforcement learning to demonstrate that the presented methods reduce training time significantly. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Compression in leg ulcer treatment: inelastic compression.

    PubMed

    Mosti, Giovanni

    2014-05-01

    Compression therapy is extremely effective in promoting ulcer healing. Which material to use, if elastic or inelastic, is still a matter of debate. This paper will provide an overview on the recent findings in compression therapy mainly for venous or mixed ulcers which are the great majority of leg ulcers. In this paper it will be demonstrated that inelastic compression has been proved to be significantly more effective than elastic compression in reducing venous reflux, increasing venous pumping function and decreasing ambulatory venous hypertension. In addition it is comfortable, well accepted by patients and achieved an extremely high healing rate in venous ulcers. With reduced pressure inelastic compression is able to improve venous pumping function in patients with mixed ulcers without affecting but improving the arterial inflow. It will be also clearly shown that studies claiming a better effect of elastic compression compared to inelastic in favouring healing rate have significant methodological flaws making their conclusions at least doubtful. In conclusion inelastic- is significantly more effective than elastic compression in reducing ambulatory venous hypertension which is the main pathophysiological determinant of venous ulcers and demonstrated to be very effective in getting ulcer healing. New multicentric, randomized and controlled studies, without methodological flaws, will be necessary to prove that elastic- is at least as effective as inelastic compression or, maybe, more effective. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  13. Microbunching and RF Compression

    SciTech Connect

    Venturini, M.; Migliorati, M.; Ronsivalle, C.; Ferrario, M.; Vaccarezza, C.

    2010-05-23

    Velocity bunching (or RF compression) represents a promising technique complementary to magnetic compression to achieve the high peak current required in the linac drivers for FELs. Here we report on recent progress aimed at characterizing the RF compression from the point of view of the microbunching instability. We emphasize the development of a linear theory for the gain function of the instability and its validation against macroparticle simulations that represents a useful tool in the evaluation of the compression schemes for FEL sources.

  14. Compressed gas manifold

    DOEpatents

    Hildebrand, Richard J.; Wozniak, John J.

    2001-01-01

    A compressed gas storage cell interconnecting manifold including a thermally activated pressure relief device, a manual safety shut-off valve, and a port for connecting the compressed gas storage cells to a motor vehicle power source and to a refueling adapter. The manifold is mechanically and pneumatically connected to a compressed gas storage cell by a bolt including a gas passage therein.

  15. Lightweight, highly compressible, noncrystalline cellulose capsules.

    PubMed

    Carrick, Christopher; Lindström, Stefan B; Larsson, Per Tomas; Wågberg, Lars

    2014-07-08

    We demonstrate how to prepare extraordinarily deformable, gas-filled, spherical capsules from nonmodified cellulose. These capsules have a low nominal density, ranging from 7.6 to 14.2 kg/m(3), and can be deformed elastically to 70% deformation at 50% relative humidity. No compressive strain-at-break could be detected for these dry cellulose capsules, since they did not rupture even when compressed into a disk with pockets of highly compressed air. A quantitative constitutive model for the large deformation compression of these capsules is derived, including their high-frequency mechanical response and their low-frequency force relaxation, where the latter is governed by the gas barrier properties of the dry capsule. Mechanical testing corroborated these models with good accuracy. Force relaxation measurements at a constant compression rendered an estimate for the gas permeability of air through the capsule wall, calculated to 0.4 mL μm/m(2) days kPa at 50% relative humidity. These properties taken together open up a large application area for the capsules, and they could most likely be used for applications in compressible, lightweight materials and also constitute excellent model materials for adsorption and adhesion studies.

  16. Wave energy devices with compressible volumes.

    PubMed

    Kurniawan, Adi; Greaves, Deborah; Chaplin, John

    2014-12-08

    We present an analysis of wave energy devices with air-filled compressible submerged volumes, where variability of volume is achieved by means of a horizontal surface free to move up and down relative to the body. An analysis of bodies without power take-off (PTO) systems is first presented to demonstrate the positive effects a compressible volume could have on the body response. Subsequently, two compressible device variations are analysed. In the first variation, the compressible volume is connected to a fixed volume via an air turbine for PTO. In the second variation, a water column separates the compressible volume from another volume, which is fitted with an air turbine open to the atmosphere. Both floating and bottom-fixed, axisymmetric, configurations are considered, and linear analysis is employed throughout. Advantages and disadvantages of each device are examined in detail. Some configurations with displaced volumes less than 2000 m(3) and with constant turbine coefficients are shown to be capable of achieving 80% of the theoretical maximum absorbed power over a wave period range of about 4 s.

  17. Wave energy devices with compressible volumes

    PubMed Central

    Kurniawan, Adi; Greaves, Deborah; Chaplin, John

    2014-01-01

    We present an analysis of wave energy devices with air-filled compressible submerged volumes, where variability of volume is achieved by means of a horizontal surface free to move up and down relative to the body. An analysis of bodies without power take-off (PTO) systems is first presented to demonstrate the positive effects a compressible volume could have on the body response. Subsequently, two compressible device variations are analysed. In the first variation, the compressible volume is connected to a fixed volume via an air turbine for PTO. In the second variation, a water column separates the compressible volume from another volume, which is fitted with an air turbine open to the atmosphere. Both floating and bottom-fixed, axisymmetric, configurations are considered, and linear analysis is employed throughout. Advantages and disadvantages of each device are examined in detail. Some configurations with displaced volumes less than 2000 m3 and with constant turbine coefficients are shown to be capable of achieving 80% of the theoretical maximum absorbed power over a wave period range of about 4 s. PMID:25484609

  18. Compressible turbulent mixing: Effects of compressibility.

    PubMed

    Ni, Qionglin

    2016-04-01

    We studied by numerical simulations the effects of compressibility on passive scalar transport in stationary compressible turbulence. The turbulent Mach number varied from zero to unity. The difference in driven forcing was the magnitude ratio of compressive to solenoidal modes. In the inertial range, the scalar spectrum followed the k^{-5/3} scaling and suffered negligible influence from the compressibility. The growth of the Mach number showed (1) a first reduction and second enhancement in the transfer of scalar flux; (2) an increase in the skewness and flatness of the scalar derivative and a decrease in the mixed skewness and flatness of the velocity-scalar derivatives; (3) a first stronger and second weaker intermittency of scalar relative to that of velocity; and (4) an increase in the intermittency parameter which measures the intermittency of scalar in the dissipative range. Furthermore, the growth of the compressive mode of forcing indicated (1) a decrease in the intermittency parameter and (2) less efficiency in enhancing scalar mixing. The visualization of scalar dissipation showed that, in the solenoidal-forced flow, the field was filled with the small-scale, highly convoluted structures, while in the compressive-forced flow, the field was exhibited as the regions dominated by the large-scale motions of rarefaction and compression.

  19. Emergency Handling of Compressed Air Casualties,

    DTIC Science & Technology

    1984-02-01

    given orally in a 50% solution of flavoured water (e.g. lemon juice ) is also helpful in reducing CNS edema. (Note: I gm = 0.8 cc glycerol and...chamber with the patient at all times unless ph sically impossible (e.g. one-man cham- ber); b. the tender must be alert for any changes in the

  20. Compression testing of ceramics

    NASA Technical Reports Server (NTRS)

    Sines, G.; Adams, M.

    1978-01-01

    The techniques for determining the compressive strengths of the rapidly developing family of super-strong, but brittle, materials is considered. The uniaxial column compression test is discussed, taking into account the loading block size mismatch, the loading block compliance mismatch, the load transmitting surfaces, and the eccentricity of loading. A description of the uniaxial hollow cylinder compression test is also provided, giving attention to premature failure from compliance tube splitting, stresses from compliance mismatch of the loading block, and premature failure from local rotations. The ring compression test is considered along with the hollow cylinder biaxial compression test.

  1. 16. DETAIL OF TOOL FOR COMPRESSING SPRING IN FAIRING SEPARATION ...

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

    16. DETAIL OF TOOL FOR COMPRESSING SPRING IN FAIRING SEPARATION ACTUATOR AND PLASTIC-WRAPPED ACTUATOR FOR FAIRING THAT WILL ENCLOSE A DMSP SATELLITE. (FAIRING SEPARATION ACTUATOR COMPRESSES TO ONE-THIRD OF ITS SIZE.) - Vandenberg Air Force Base, Space Launch Complex 3, Vehicle Support Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  2. RUNNER BOX MAINTENANCE. FRANK FEHER USES A COMPRESSED AIRPOWERED CHISEL ...

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

    RUNNER BOX MAINTENANCE. FRANK FEHER USES A COMPRESSED AIR-POWERED CHISEL TO CHIP OUT CONGEALED METAL IN PREPARATION FOR ANOTHER HEAT. - American Brass Foundry, 70 Sayre Street, Buffalo, Erie County, NY

  3. Adiabatic Compression in a Fire Syringe.

    ERIC Educational Resources Information Center

    Hayn, Carl H.; Baird, Scott C.

    1985-01-01

    Suggests using better materials in fire syringes to obtain more effective results during demonstrations which show the elevation in temperature upon a very rapid (adiabatic) compression of air. Also describes an experiment (using ignition temperatures) which introduces students to the use of thermocouples for high temperature measurements. (DH)

  4. Computer program for compressible flow network analysis

    NASA Technical Reports Server (NTRS)

    Wilton, M. E.; Murtaugh, J. P.

    1973-01-01

    Program solves problem of an arbitrarily connected one dimensional compressible flow network with pumping in the channels and momentum balancing at flow junctions. Program includes pressure drop calculations for impingement flow and flow through pin fin arrangements, as currently found in many air cooled turbine bucket and vane cooling configurations.

  5. Adiabatic Compression in a Fire Syringe.

    ERIC Educational Resources Information Center

    Hayn, Carl H.; Baird, Scott C.

    1985-01-01

    Suggests using better materials in fire syringes to obtain more effective results during demonstrations which show the elevation in temperature upon a very rapid (adiabatic) compression of air. Also describes an experiment (using ignition temperatures) which introduces students to the use of thermocouples for high temperature measurements. (DH)

  6. [Evidence of compression therapy].

    PubMed

    Konschake, W; Valesky, E; Stege, H; Jünger, M

    2017-08-01

    Medical compression therapy is widely used to treat phlebologic diseases. Compression bandages as well as compression stockings are used. Compression has been identified to be an effective conservative therapy for the healing of venous ulcers and other indications. Thus, the evidence for the use of medical compression therapy and for which indications is presented. Review and systematic presentation of the evidence-based use of compression. The current literature, guidelines, and consensus statements were searched and the indications for compression therapy are presented. There is a high level of evidence that compression therapy is effective to heal venous ulcers and to prevent recurrent ulcers. The use of compression bandages and hosiery after interventional and surgical procedures for varicose veins is based on experience but not on randomized controlled trials. According to clinical experience, the healing of inflammatory skin diseases (e.g., erythema nodosum, pyoderma gangrenosum, necrobiosis lipoidica, cutaneous leukocytoclastic vasculitis, and psoriasis of the extremities) is supported by compression therapy. Compression therapy in patients suffering from venous ulcers is highly recommended.

  7. 30 CFR 7.506 - Breathable air components.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Breathable air components. 7.506 Section 7.506... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Refuge Alternatives § 7.506 Breathable air components. (a) Breathable air shall be supplied by compressed air cylinders, compressed...

  8. 30 CFR 7.506 - Breathable air components.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Breathable air components. 7.506 Section 7.506... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Refuge Alternatives § 7.506 Breathable air components. (a) Breathable air shall be supplied by compressed air cylinders, compressed...

  9. Photovoltaic driven vapor compression cycles

    NASA Astrophysics Data System (ADS)

    Anand, D. K.

    Since the vast majority of heat pumps, air conditioning and refrigeration equipment employs the vapor compression cycle (VCC), the use of renewable energy represents a significant opportunity. As discussed in this report, it is clear that the use of photovoltaics (PV) to drive the VCC has more potential than any other active solar cooling approach. This potential exists due to improvements in not only the PV cells but VCC machinery and control algorithms. It is estimated that the combined improvements will result in reducing the PV cell requirements by as much as one half.

  10. High Strain Rate Tensile and Compressive Effects in Glassy Polymers

    DTIC Science & Technology

    2013-02-08

    polymers under high strain rates has been determined in compression. Some research programs have studied the combined effects of temperature and strain rate...glassy polymers to high strain rate loading in compression. More recently, research programs that study the combined effects of temperature and strain...Force Materiel Command  United States Air Force  Eglin Air Force Base AFRL-RW-EG-TP-2013-006 High Strain Rate

  11. ALTERNATIVE TECHNOLOGIES FOR REFRIGERATION AND AIR-CONDITIONING APPLICATIONS

    EPA Science Inventory

    The report gives results of an assessment of refrigeration technologies that are alternatives to vapor compression refrigeration for use in five application categories: domestic air conditioning, commercial air conditioning, mobile air conditioning, domestic refrigeration, and co...

  12. ALTERNATIVE TECHNOLOGIES FOR REFRIGERATION AND AIR-CONDITIONING APPLICATIONS

    EPA Science Inventory

    The report gives results of an assessment of refrigeration technologies that are alternatives to vapor compression refrigeration for use in five application categories: domestic air conditioning, commercial air conditioning, mobile air conditioning, domestic refrigeration, and co...

  13. Parallel image compression

    NASA Technical Reports Server (NTRS)

    Reif, John H.

    1987-01-01

    A parallel compression algorithm for the 16,384 processor MPP machine was developed. The serial version of the algorithm can be viewed as a combination of on-line dynamic lossless test compression techniques (which employ simple learning strategies) and vector quantization. These concepts are described. How these concepts are combined to form a new strategy for performing dynamic on-line lossy compression is discussed. Finally, the implementation of this algorithm in a massively parallel fashion on the MPP is discussed.

  14. Air supply valve for seismic air gun

    SciTech Connect

    Otto, B.

    1989-07-25

    This paper describes an improvement in a marine seismic array adapted to be towed by a vessel wherein the array is comprised of a plurality of air guns spaced along an array bundle which includes a central air hose assembly that supplies compressed air to each of the air guns through individual air passages which extend between the central air hose assembly and each of the air guns. The improvement comprising: an air supply valve positioned in each of the individual air passages, the air supply valve comprising: a housing having inlet and an outlet and a passage in the housing connecting the inlet and the outlet; valve means positioned in the passage in the housing; valve actuating means in the housing for moving the valve means from an open position to a closed position and from a closed position to an open position; means for remotely actuating the valve actuating means from the vessel to close the valve to deactivate the air gun and to reopen the valve to reactivate the air gun whereby each of the plurality of air guns can be individually inactivated and reactivated remotely from the vessel.

  15. HYDRODYNAMIC COMPRESSIVE FORGING.

    DTIC Science & Technology

    HYDRODYNAMICS), (*FORGING, COMPRESSIVE PROPERTIES, LUBRICANTS, PERFORMANCE(ENGINEERING), DIES, TENSILE PROPERTIES, MOLYBDENUM ALLOYS , STRAIN...MECHANICS), BERYLLIUM ALLOYS , NICKEL ALLOYS , CASTING ALLOYS , PRESSURE, FAILURE(MECHANICS).

  16. Controlling And Operating Homogeneous Charge Compression Ignition (Hcci) Engines

    DOEpatents

    Flowers, Daniel L.

    2005-08-02

    A Homogeneous Charge Compression Ignition (HCCI) engine system includes an engine that produces exhaust gas. A vaporization means vaporizes fuel for the engine an air induction means provides air for the engine. An exhaust gas recirculation means recirculates the exhaust gas. A blending means blends the vaporized fuel, the exhaust gas, and the air. An induction means inducts the blended vaporized fuel, exhaust gas, and air into the engine. A control means controls the blending of the vaporized fuel, the exhaust gas, and the air and for controls the inducting the blended vaporized fuel, exhaust gas, and air into the engine.

  17. Low-Complexity Adaptive Lossless Compression of Hyperspectral Imagery

    NASA Technical Reports Server (NTRS)

    Klimesh, Matthew

    2006-01-01

    A low-complexity, adaptive predictive technique for lossless compression of hyperspectral imagery is described. This technique is designed to be suitable for implementation in hardware such as a field programmable gate array (FPGA); such an implementation could be used for high-speed compression of hyperspectral imagery onboard a spacecraft. The predictive step of the technique makes use of the sign algorithm, which is a relative of the least mean square (LMS) algorithm from the field of low-complexity adaptive filtering. The compressed data stream consists of prediction residuals encoded using a method similar to that of the JPEG-LS lossless image compression standard. Compression results are presented for several datasets including some raw Airborne Visible/ Infrared Imaging Spectrometer (AVIRIS) datasets and raw Atmospheric Infrared Sounder (AIRS) datasets. The compression effectiveness obtained with the technique is competitive with that of the best of previously described techniques with similar complexity.

  18. Compression Ratio Adjuster

    NASA Technical Reports Server (NTRS)

    Akkerman, J. W.

    1982-01-01

    New mechanism alters compression ratio of internal-combustion engine according to load so that engine operates at top fuel efficiency. Ordinary gasoline, diesel and gas engines with their fixed compression ratios are inefficient at partial load and at low-speed full load. Mechanism ensures engines operate as efficiently under these conditions as they do at highload and high speed.

  19. Chest compression rate measurement from smartphone video.

    PubMed

    Engan, Kjersti; Hinna, Thomas; Ryen, Tom; Birkenes, Tonje S; Myklebust, Helge

    2016-08-11

    Out-of-hospital cardiac arrest is a life threatening situation where the first person performing cardiopulmonary resuscitation (CPR) most often is a bystander without medical training. Some existing smartphone apps can call the emergency number and provide for example global positioning system (GPS) location like Hjelp 113-GPS App by the Norwegian air ambulance. We propose to extend functionality of such apps by using the built in camera in a smartphone to capture video of the CPR performed, primarily to estimate the duration and rate of the chest compression executed, if any. All calculations are done in real time, and both the caller and the dispatcher will receive the compression rate feedback when detected. The proposed algorithm is based on finding a dynamic region of interest in the video frames, and thereafter evaluating the power spectral density by computing the fast fourier transform over sliding windows. The power of the dominating frequencies is compared to the power of the frequency area of interest. The system is tested on different persons, male and female, in different scenarios addressing target compression rates, background disturbances, compression with mouth-to-mouth ventilation, various background illuminations and phone placements. All tests were done on a recording Laerdal manikin, providing true compression rates for comparison. Overall, the algorithm is seen to be promising, and it manages a number of disturbances and light situations. For target rates at 110 cpm, as recommended during CPR, the mean error in compression rate (Standard dev. over tests in parentheses) is 3.6 (0.8) for short hair bystanders, and 8.7 (6.0) including medium and long haired bystanders. The presented method shows that it is feasible to detect the compression rate of chest compressions performed by a bystander by placing the smartphone close to the patient, and using the built-in camera combined with a video processing algorithm performed real-time on the device.

  20. 26. Central compression lock, north span facing north. Compression lock ...

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

    26. Central compression lock, north span facing north. Compression lock locks two spans together at highest point. There are three compression locks. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

  1. Fractal image compression

    NASA Technical Reports Server (NTRS)

    Barnsley, Michael F.; Sloan, Alan D.

    1989-01-01

    Fractals are geometric or data structures which do not simplify under magnification. Fractal Image Compression is a technique which associates a fractal to an image. On the one hand, the fractal can be described in terms of a few succinct rules, while on the other, the fractal contains much or all of the image information. Since the rules are described with less bits of data than the image, compression results. Data compression with fractals is an approach to reach high compression ratios for large data streams related to images. The high compression ratios are attained at a cost of large amounts of computation. Both lossless and lossy modes are supported by the technique. The technique is stable in that small errors in codes lead to small errors in image data. Applications to the NASA mission are discussed.

  2. Negative linear compressibility.

    PubMed

    Cairns, Andrew B; Goodwin, Andrew L

    2015-08-28

    While all materials reduce their intrinsic volume under hydrostatic (uniform) compression, a select few actually expand along one or more directions during this process of densification. As rare as it is counterintuitive, such "negative compressibility" behaviour has application in the design of pressure sensors, artificial muscles and actuators. The recent discovery of surprisingly strong and persistent negative compressibility effects in a variety of new families of materials has ignited the field. Here we review the phenomenology of negative compressibility in this context of materials diversity, placing particular emphasis on the common structural motifs that recur amongst known examples. Our goal is to present a mechanistic understanding of negative compressibility that will help inform a clear strategy for future materials design.

  3. Vascular compression syndromes.

    PubMed

    Czihal, Michael; Banafsche, Ramin; Hoffmann, Ulrich; Koeppel, Thomas

    2015-11-01

    Dealing with vascular compression syndromes is one of the most challenging tasks in Vascular Medicine practice. This heterogeneous group of disorders is characterised by external compression of primarily healthy arteries and/or veins as well as accompanying nerval structures, carrying the risk of subsequent structural vessel wall and nerve damage. Vascular compression syndromes may severely impair health-related quality of life in affected individuals who are typically young and otherwise healthy. The diagnostic approach has not been standardised for any of the vascular compression syndromes. Moreover, some degree of positional external compression of blood vessels such as the subclavian and popliteal vessels or the celiac trunk can be found in a significant proportion of healthy individuals. This implies important difficulties in differentiating physiological from pathological findings of clinical examination and diagnostic imaging with provocative manoeuvres. The level of evidence on which treatment decisions regarding surgical decompression with or without revascularisation can be relied on is generally poor, mostly coming from retrospective single centre studies. Proper patient selection is critical in order to avoid overtreatment in patients without a clear association between vascular compression and clinical symptoms. With a focus on the thoracic outlet-syndrome, the median arcuate ligament syndrome and the popliteal entrapment syndrome, the present article gives a selective literature review on compression syndromes from an interdisciplinary vascular point of view.

  4. CSAM: Compressed SAM format.

    PubMed

    Cánovas, Rodrigo; Moffat, Alistair; Turpin, Andrew

    2016-12-15

    Next generation sequencing machines produce vast amounts of genomic data. For the data to be useful, it is essential that it can be stored and manipulated efficiently. This work responds to the combined challenge of compressing genomic data, while providing fast access to regions of interest, without necessitating decompression of whole files. We describe CSAM (Compressed SAM format), a compression approach offering lossless and lossy compression for SAM files. The structures and techniques proposed are suitable for representing SAM files, as well as supporting fast access to the compressed information. They generate more compact lossless representations than BAM, which is currently the preferred lossless compressed SAM-equivalent format; and are self-contained, that is, they do not depend on any external resources to compress or decompress SAM files. An implementation is available at https://github.com/rcanovas/libCSAM CONTACT: canovas-ba@lirmm.frSupplementary Information: Supplementary data is available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. Modeling Compressed Turbulence

    SciTech Connect

    Israel, Daniel M.

    2012-07-13

    From ICE to ICF, the effect of mean compression or expansion is important for predicting the state of the turbulence. When developing combustion models, we would like to know the mix state of the reacting species. This involves density and concentration fluctuations. To date, research has focused on the effect of compression on the turbulent kinetic energy. The current work provides constraints to help development and calibration for models of species mixing effects in compressed turbulence. The Cambon, et al., re-scaling has been extended to buoyancy driven turbulence, including the fluctuating density, concentration, and temperature equations. The new scalings give us helpful constraints for developing and validating RANS turbulence models.

  6. Compression behavior of single-layer graphenes.

    PubMed

    Frank, Otakar; Tsoukleri, Georgia; Parthenios, John; Papagelis, Konstantinos; Riaz, Ibtsam; Jalil, Rashid; Novoselov, Kostya S; Galiotis, Costas

    2010-06-22

    Central to most applications involving monolayer graphenes is its mechanical response under various stress states. To date most of the work reported is of theoretical nature and refers to tension and compression loading of model graphenes. Most of the experimental work is indeed limited to the bending of single flakes in air and the stretching of flakes up to typically approximately 1% using plastic substrates. Recently we have shown that by employing a cantilever beam we can subject single graphenes to various degrees of axial compression. Here we extend this work much further by measuring in detail both stress uptake and compression buckling strain in single flakes of different geometries. In all cases the mechanical response is monitored by simultaneous Raman measurements through the shift of either the G or 2D phonons of graphene. Despite the infinitely small thickness of the monolayers, the results show that graphenes embedded in plastic beams exhibit remarkable compression buckling strains. For large length (l)-to-width (w) ratios (> or =0.2) the buckling strain is of the order of -0.5% to -0.6%. However, for l/w < 0.2 no failure is observed for strains even higher than -1%. Calculations based on classical Euler analysis show that the buckling strain enhancement provided by the polymer lateral support is more than 6 orders of magnitude compared to that of suspended graphene in air.

  7. Compressive holographic video.

    PubMed

    Wang, Zihao; Spinoulas, Leonidas; He, Kuan; Tian, Lei; Cossairt, Oliver; Katsaggelos, Aggelos K; Chen, Huaijin

    2017-01-09

    Compressed sensing has been discussed separately in spatial and temporal domains. Compressive holography has been introduced as a method that allows 3D tomographic reconstruction at different depths from a single 2D image. Coded exposure is a temporal compressed sensing method for high speed video acquisition. In this work, we combine compressive holography and coded exposure techniques and extend the discussion to 4D reconstruction in space and time from one coded captured image. In our prototype, digital in-line holography was used for imaging macroscopic, fast moving objects. The pixel-wise temporal modulation was implemented by a digital micromirror device. In this paper we demonstrate 10× temporal super resolution with multiple depths recovery from a single image. Two examples are presented for the purpose of recording subtle vibrations and tracking small particles within 5 ms.

  8. Compressive optical image encryption.

    PubMed

    Li, Jun; Sheng Li, Jiao; Yang Pan, Yang; Li, Rong

    2015-05-20

    An optical image encryption technique based on compressive sensing using fully optical means has been proposed. An object image is first encrypted to a white-sense stationary noise pattern using a double random phase encoding (DRPE) method in a Mach-Zehnder interferometer. Then, the encrypted image is highly compressed to a signal using single-pixel compressive holographic imaging in the optical domain. At the receiving terminal, the encrypted image is reconstructed well via compressive sensing theory, and the original image can be decrypted with three reconstructed holograms and the correct keys. The numerical simulations show that the method is effective and suitable for optical image security transmission in future all-optical networks because of the ability of completely optical implementation and substantially smaller hologram data volume.

  9. Compressive Optical Image Encryption

    PubMed Central

    Li, Jun; Sheng Li, Jiao; Yang Pan, Yang; Li, Rong

    2015-01-01

    An optical image encryption technique based on compressive sensing using fully optical means has been proposed. An object image is first encrypted to a white-sense stationary noise pattern using a double random phase encoding (DRPE) method in a Mach-Zehnder interferometer. Then, the encrypted image is highly compressed to a signal using single-pixel compressive holographic imaging in the optical domain. At the receiving terminal, the encrypted image is reconstructed well via compressive sensing theory, and the original image can be decrypted with three reconstructed holograms and the correct keys. The numerical simulations show that the method is effective and suitable for optical image security transmission in future all-optical networks because of the ability of completely optical implementation and substantially smaller hologram data volume. PMID:25992946

  10. Compressible Astrophysics Simulation Code

    SciTech Connect

    Howell, L.; Singer, M.

    2007-07-18

    This is an astrophysics simulation code involving a radiation diffusion module developed at LLNL coupled to compressible hydrodynamics and adaptive mesh infrastructure developed at LBNL. One intended application is to neutrino diffusion in core collapse supernovae.

  11. Compressive holographic video

    NASA Astrophysics Data System (ADS)

    Wang, Zihao; Spinoulas, Leonidas; He, Kuan; Tian, Lei; Cossairt, Oliver; Katsaggelos, Aggelos K.; Chen, Huaijin

    2017-01-01

    Compressed sensing has been discussed separately in spatial and temporal domains. Compressive holography has been introduced as a method that allows 3D tomographic reconstruction at different depths from a single 2D image. Coded exposure is a temporal compressed sensing method for high speed video acquisition. In this work, we combine compressive holography and coded exposure techniques and extend the discussion to 4D reconstruction in space and time from one coded captured image. In our prototype, digital in-line holography was used for imaging macroscopic, fast moving objects. The pixel-wise temporal modulation was implemented by a digital micromirror device. In this paper we demonstrate $10\\times$ temporal super resolution with multiple depths recovery from a single image. Two examples are presented for the purpose of recording subtle vibrations and tracking small particles within 5 ms.

  12. Compressive laser ranging.

    PubMed

    Babbitt, Wm Randall; Barber, Zeb W; Renner, Christoffer

    2011-12-15

    Compressive sampling has been previously proposed as a technique for sampling radar returns and determining sparse range profiles with a reduced number of measurements compared to conventional techniques. By employing modulation on both transmission and reception, compressive sensing in ranging is extended to the direct measurement of range profiles without intermediate measurement of the return waveform. This compressive ranging approach enables the use of pseudorandom binary transmit waveforms and return modulation, along with low-bandwidth optical detectors to yield high-resolution ranging information. A proof-of-concept experiment is presented. With currently available compact, off-the-shelf electronics and photonics, such as high data rate binary pattern generators and high-bandwidth digital optical modulators, compressive laser ranging can readily achieve subcentimeter resolution in a compact, lightweight package.

  13. Muon cooling: longitudinal compression.

    PubMed

    Bao, Yu; Antognini, Aldo; Bertl, Wilhelm; Hildebrandt, Malte; Khaw, Kim Siang; Kirch, Klaus; Papa, Angela; Petitjean, Claude; Piegsa, Florian M; Ritt, Stefan; Sedlak, Kamil; Stoykov, Alexey; Taqqu, David

    2014-06-06

    A 10  MeV/c positive muon beam was stopped in helium gas of a few mbar in a magnetic field of 5 T. The muon "swarm" has been efficiently compressed from a length of 16 cm down to a few mm along the magnetic field axis (longitudinal compression) using electrostatic fields. The simulation reproduces the low energy interactions of slow muons in helium gas. Phase space compression occurs on the order of microseconds, compatible with the muon lifetime of 2  μs. This paves the way for the preparation of a high-quality low-energy muon beam, with an increase in phase space density relative to a standard surface muon beam of 10^{7}. The achievable phase space compression by using only the longitudinal stage presented here is of the order of 10^{4}.

  14. Vertebral Compression Fractures

    MedlinePlus

    ... OI: Information on Vertebral Compression Fractures 804 W. Diamond Ave., Ste. 210 Gaithersburg, MD 20878 (800) 981- ... osteogenesis imperfecta contact : Osteogenesis Imperfecta Foundation 804 W. Diamond Avenue, Suite 210, Gaithersburg, MD 20878 Tel: 800- ...

  15. Lightweight SIP/SDP compression scheme (LSSCS)

    NASA Astrophysics Data System (ADS)

    Wu, Jian J.; Demetrescu, Cristian

    2001-10-01

    In UMTS new IP based services with tight delay constraints will be deployed over the W-CDMA air interface such as IP multimedia and interactive services. To integrate the wireline and wireless IP services, 3GPP standard forum adopted the Session Initiation Protocol (SIP) as the call control protocol for the UMTS Release 5, which will implement next generation, all IP networks for real-time QoS services. In the current form the SIP protocol is not suitable for wireless transmission due to its large message size which will need either a big radio pipe for transmission or it will take far much longer to transmit than the current GSM Call Control (CC) message sequence. In this paper we present a novel compression algorithm called Lightweight SIP/SDP Compression Scheme (LSSCS), which acts at the SIP application layer and therefore removes the information redundancy before it is sent to the network and transport layer. A binary octet-aligned header is added to the compressed SIP/SDP message before sending it to the network layer. The receiver uses this binary header as well as the pre-cached information to regenerate the original SIP/SDP message. The key features of the LSSCS compression scheme are presented in this paper along with implementation examples. It is shown that this compression algorithm makes SIP transmission efficient over the radio interface without losing the SIP generality and flexibility.

  16. Collapse dynamics of bubble raft under compression

    NASA Astrophysics Data System (ADS)

    Kuo, Chin-Chang; Kachan, Devin; Levine, Alexander; Dennin, Michael; Department of Physics; Astronomy, University of California, Irvine Collaboration; Department of Physics; Astronomy, University of California, Los Angeles Collaboration

    2015-03-01

    We report on the collapse of bubble rafts under compression in a closed rectangular geometry. A bubble raft is a single layer of bubbles at the air-water interface. A collapse event occurs when bubbles submerge beneath the neighboring bubbles under applied compression causing the structure of the bubble raft to go from single-layer to multi-layer. We studied the collapse dynamics as a function of compression velocity. At higher compression velocity we observe a more uniform distribution of collapse events, whereas at lower compression velocities, the collapse events accumulate at the system boundaries. We will present results that compare the distribution of collapse probability in the experiments to simulations based on a one-dimensional Ising model with elastic coupling between spin elements. Both the experimental system and simulations are excellent models for collapse in a number of complex systems. By comparing the two systems, we can tune the simulation to better understand the role of the Ising and elastic couplings in determining the collapse dynamics. We acknowledge DMR-1309402.

  17. Compression molding of aerogel microspheres

    DOEpatents

    Pekala, R.W.; Hrubesh, L.W.

    1998-03-24

    An aerogel composite material produced by compression molding of aerogel microspheres (powders) mixed together with a small percentage of polymer binder to form monolithic shapes in a cost-effective manner is disclosed. The aerogel composites are formed by mixing aerogel microspheres with a polymer binder, placing the mixture in a mold and heating under pressure, which results in a composite with a density of 50--800 kg/m{sup 3} (0.05--0.80 g/cc). The thermal conductivity of the thus formed aerogel composite is below that of air, but higher than the thermal conductivity of monolithic aerogels. The resulting aerogel composites are attractive for applications such as thermal insulation since fabrication thereof does not require large and expensive processing equipment. In addition to thermal insulation, the aerogel composites may be utilized for filtration, ICF target, double layer capacitors, and capacitive deionization. 4 figs.

  18. Compression molding of aerogel microspheres

    DOEpatents

    Pekala, Richard W.; Hrubesh, Lawrence W.

    1998-03-24

    An aerogel composite material produced by compression molding of aerogel microspheres (powders) mixed together with a small percentage of polymer binder to form monolithic shapes in a cost-effective manner. The aerogel composites are formed by mixing aerogel microspheres with a polymer binder, placing the mixture in a mold and heating under pressure, which results in a composite with a density of 50-800 kg/m.sup.3 (0.05-0.80 g/cc). The thermal conductivity of the thus formed aerogel composite is below that of air, but higher than the thermal conductivity of monolithic aerogels. The resulting aerogel composites are attractive for applications such as thermal insulation since fabrication thereof does not require large and expensive processing equipment. In addition to thermal insulation, the aerogel composites may be utilized for filtration, ICF target, double layer capacitors, and capacitive deionization.

  19. Shock compression of liquid hydrazine

    SciTech Connect

    Garcia, B.O.; Chavez, D.J.

    1995-01-01

    Liquid hydrazine (N{sub 2}H{sub 4}) is a propellant used by the Air Force and NASA for aerospace propulsion and power systems. Because the propellant modules that contain the hydrazine can be subject to debris impacts during their use, the shock states that can occur in the hydrazine need to be characterized to safely predict its response. Several shock compression experiments have been conducted in an attempt to investigate the detonability of liquid hydrazine; however, the experiments results disagree. Therefore, in this study, we reproduced each experiment numerically to evaluate in detail the shock wave profiles generated in the liquid hydrazine. This paper presents the results of each numerical simulation and compares the results to those obtained in experiment. We also present the methodology of our approach, which includes chemical kinetic experiments, chemical equilibrium calculations, and characterization of the equation of state of liquid hydrazine.

  20. Smoothing DCT Compression Artifacts

    NASA Technical Reports Server (NTRS)

    Ahumada, A. J., Jr.; Horng, R.; Statler, Irving C. (Technical Monitor)

    1994-01-01

    Image compression based on quantizing the image in the discrete cosine transform (DCT) domain can generate blocky artifacts in the output image. It is possible to reduce these artifacts and RMS error by adjusting measures of block edginess and image roughness, while restricting the DCT coefficient values to values that would have been quantized to those of the compressed image. We also introduce a DCT coefficient amplitude adjustment that reduces RMS error.

  1. Image compression technique

    DOEpatents

    Fu, C.Y.; Petrich, L.I.

    1997-03-25

    An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace`s equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image. 16 figs.

  2. Alternative Compression Garments

    NASA Technical Reports Server (NTRS)

    Stenger, M. B.; Lee, S. M. C.; Ribeiro, L. C.; Brown, A. K.; Westby, C. M.; Platts, S. H.

    2011-01-01

    Orthostatic intolerance after spaceflight is still an issue for astronauts as no in-flight countermeasure has been 100% effective. Future anti-gravity suits (AGS) may be similar to the Shuttle era inflatable AGS or may be a mechanical compression device like the Russian Kentavr. We have evaluated the above garments as well as elastic, gradient compression garments of varying magnitude and determined that breast-high elastic compression garments may be a suitable replacement to the current AGS. This new garment should be more comfortable than the AGS, easy to don and doff, and as effective a countermeasure to orthostatic intolerance. Furthermore, these new compression garments could be worn for several days after space flight as necessary if symptoms persisted. We conducted two studies to evaluate elastic, gradient compression garments. The purpose of these studies was to evaluate the comfort and efficacy of an alternative compression garment (ACG) immediately after actual space flight and 6 degree head-down tilt bed rest as a model of space flight, and to determine if they would impact recovery if worn for up to three days after bed rest.

  3. Image compression technique

    DOEpatents

    Fu, Chi-Yung; Petrich, Loren I.

    1997-01-01

    An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace's equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image.

  4. Intelligent bandwith compression

    NASA Astrophysics Data System (ADS)

    Tseng, D. Y.; Bullock, B. L.; Olin, K. E.; Kandt, R. K.; Olsen, J. D.

    1980-02-01

    The feasibility of a 1000:1 bandwidth compression ratio for image transmission has been demonstrated using image-analysis algorithms and a rule-based controller. Such a high compression ratio was achieved by first analyzing scene content using auto-cueing and feature-extraction algorithms, and then transmitting only the pertinent information consistent with mission requirements. A rule-based controller directs the flow of analysis and performs priority allocations on the extracted scene content. The reconstructed bandwidth-compressed image consists of an edge map of the scene background, with primary and secondary target windows embedded in the edge map. The bandwidth-compressed images are updated at a basic rate of 1 frame per second, with the high-priority target window updated at 7.5 frames per second. The scene-analysis algorithms used in this system together with the adaptive priority controller are described. Results of simulated 1000:1 band width-compressed images are presented. A video tape simulation of the Intelligent Bandwidth Compression system has been produced using a sequence of video input from the data base.

  5. Compressed image deblurring

    NASA Astrophysics Data System (ADS)

    Xu, Yuquan; Hu, Xiyuan; Peng, Silong

    2014-03-01

    We propose an algorithm to recover the latent image from the blurred and compressed input. In recent years, although many image deblurring algorithms have been proposed, most of the previous methods do not consider the compression effect in blurry images. Actually, it is unavoidable in practice that most of the real-world images are compressed. This compression will introduce a typical kind of noise, blocking artifacts, which do not meet the Gaussian distribution assumed in most existing algorithms. Without properly handling this non-Gaussian noise, the recovered image will suffer severe artifacts. Inspired by the statistic property of compression error, we model the non-Gaussian noise as hyper-Laplacian distribution. Based on this model, an efficient nonblind image deblurring algorithm based on variable splitting technique is proposed to solve the resulting nonconvex minimization problem. Finally, we also address an effective blind image deblurring algorithm which can deal with the compressed and blurred images efficiently. Extensive experiments compared with state-of-the-art nonblind and blind deblurring methods demonstrate the effectiveness of the proposed method.

  6. Combined rankine and vapor compression cycles

    DOEpatents

    Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

    2005-04-19

    An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor. In another embodiment, an organic rankine cycle system is applied to an internal combustion engine to cool the fluids thereof, and the turbo charged air is cooled first by the organic rankine cycle system and then by an air conditioner prior to passing into the intake of the engine.

  7. Ames Air Revitalization

    NASA Technical Reports Server (NTRS)

    Huang, Roger Z.

    2015-01-01

    This is an informal presentation presented to the University of Colorado, Boulder Bioastronautics group seminar. It highlights the key focal areas of the Air Revitalization Group research over the past year, including progress on the CO2 Removal and Compression System, testing of CDRA drying bed configurations, and adsorption research.

  8. The Quiescent-Chamber Type Compression-Ignition Engine

    NASA Technical Reports Server (NTRS)

    Foster, H H

    1937-01-01

    Report presents the results of performance tests of a single-cylinder 4-stroke-cycle compression-ignition engine having a vertical disk form of combustion chamber without air flow. The number, size, and direction of the orifices of the fuel-injection nozzles used were independently varied. A table and graphs are presented showing the performance of the engine with different nozzles; results of tests at different compression ratios, boost pressures, and coolant temperatures are also included.

  9. Variable valve timing in a homogenous charge compression ignition engine

    DOEpatents

    Lawrence, Keith E.; Faletti, James J.; Funke, Steven J.; Maloney, Ronald P.

    2004-08-03

    The present invention relates generally to the field of homogenous charge compression ignition engines, in which fuel is injected when the cylinder piston is relatively close to the bottom dead center position for its compression stroke. The fuel mixes with air in the cylinder during the compression stroke to create a relatively lean homogeneous mixture that preferably ignites when the piston is relatively close to the top dead center position. However, if the ignition event occurs either earlier or later than desired, lowered performance, engine misfire, or even engine damage, can result. The present invention utilizes internal exhaust gas recirculation and/or compression ratio control to control the timing of ignition events and combustion duration in homogeneous charge compression ignition engines. Thus, at least one electro-hydraulic assist actuator is provided that is capable of mechanically engaging at least one cam actuated intake and/or exhaust valve.

  10. Internal sleeve air release control apparatus in seismic air gun

    SciTech Connect

    Johnston, R.C.; Thomson, J.T.

    1981-01-27

    Disclosed is a seismic source device, known in the industry as an air gun, having internal sleeve and shuttle control for allowing a predetermined discharge of compressed air into water for purposes of seismic exploration. The shuttle engages an internal sleeve having ports that momentarily align with exhaust ports and then moves past, sealing off the exhaust ports before all of the compressed air in the firing chamber of the air gun is exhausted. By preventing further discharge of air with little or no loss in acoustic output, pulses are greatly reduced, thereby enhancing the operation of the entire system. Further by preventing all the air in the firing chamber from being discharged, the system becomes more efficient and more cost effective.

  11. Transverse Compression of Tendons.

    PubMed

    Salisbury, S T Samuel; Buckley, C Paul; Zavatsky, Amy B

    2016-04-01

    A study was made of the deformation of tendons when compressed transverse to the fiber-aligned axis. Bovine digital extensor tendons were compression tested between flat rigid plates. The methods included: in situ image-based measurement of tendon cross-sectional shapes, after preconditioning but immediately prior to testing; multiple constant-load creep/recovery tests applied to each tendon at increasing loads; and measurements of the resulting tendon displacements in both transverse directions. In these tests, friction resisted axial stretch of the tendon during compression, giving approximately plane-strain conditions. This, together with the assumption of a form of anisotropic hyperelastic constitutive model proposed previously for tendon, justified modeling the isochronal response of tendon as that of an isotropic, slightly compressible, neo-Hookean solid. Inverse analysis, using finite-element (FE) simulations of the experiments and 10 s isochronal creep displacement data, gave values for Young's modulus and Poisson's ratio of this solid of 0.31 MPa and 0.49, respectively, for an idealized tendon shape and averaged data for all the tendons and E = 0.14 and 0.10 MPa for two specific tendons using their actual measured geometry. The compression load versus displacement curves, as measured and as simulated, showed varying degrees of stiffening with increasing load. This can be attributed mostly to geometrical changes in tendon cross section under load, varying according to the initial 3D shape of the tendon.

  12. Intelligent bandwidth compression

    NASA Astrophysics Data System (ADS)

    Tseng, D. Y.; Bullock, B. L.; Olin, K. E.; Kandt, R. K.; Olsen, J. D.

    1980-02-01

    The feasibility of a 1000:1 bandwidth compression ratio for image transmission has been demonstrated using image-analysis algorithms and a rule-based controller. Such a high compression ratio was achieved by first analyzing scene content using auto-cueing and feature-extraction algorithms, and then transmitting only the pertinent information consistent with mission requirements. A rule-based controller directs the flow of analysis and performs priority allocations on the extracted scene content. The reconstructed bandwidth-compressed image consists of an edge map of the scene background, with primary and secondary target windows embedded in the edge map. The bandwidth-compressed images are updated at a basic rate of 1 frame per second, with the high-priority target window updated at 7.5 frames per second. The scene-analysis algorithms used in this system together with the adaptive priority controller are described. Results of simulated 1000:1 bandwidth-compressed images are presented.

  13. Compressibility variations of JPEG2000 compressed computed tomography.

    PubMed

    Pambrun, Jean-François; Noumeir, Rita

    2013-01-01

    Compression is increasingly used in medical applications to enable efficient and universally accessible electronic health records. However, lossy compression introduces artifacts that can alter diagnostic accuracy, interfere with image processing algorithms and cause liability issues in cases of diagnostic errors. Compression guidelines were introduced to mitigate these issues and foster the use of modern compression algorithms with diagnostic imaging. However, these guidelines are usually defined as maximum compression ratios for each imaging protocol and do not take compressibility variations due to image content into account. In this paper we have evaluated the compressibility of thousands of computed tomography slices of an anthropomorphic thoracic phantom acquired with different parameters. We have shown that exposure, slice thickness and reconstruction filters have a significant impact on compressibility suggesting that guidelines based solely on compression ratios may be inadequate.

  14. The compressible mixing layer

    NASA Technical Reports Server (NTRS)

    Vandromme, Dany; Haminh, Hieu

    1991-01-01

    The capability of turbulence modeling correctly to handle natural unsteadiness appearing in compressible turbulent flows is investigated. Physical aspects linked to the unsteadiness problem and the role of various flow parameters are analyzed. It is found that unsteady turbulent flows can be simulated by dividing these motions into an 'organized' part for which equations of motion are solved and a remaining 'incoherent' part represented by a turbulence model. Two-equation turbulence models and second-order turbulence models can yield reasonable results. For specific compressible unsteady turbulent flow, graphic presentations of different quantities may reveal complementary physical features. Strong compression zones are observed in rapid flow parts but shocklets do not yet occur.

  15. Isentropic Compression of Argon

    SciTech Connect

    H. Oona; J.C. Solem; L.R. Veeser, C.A. Ekdahl; P.J. Rodriquez; S.M. Younger; W. Lewis; W.D. Turley

    1997-08-01

    We are studying the transition of argon from an insulator to a conductor by compressing the frozen gas isentropically to pressures at which neighboring atomic orbitals overlap sufficiently to allow some electron motion between atoms. Argon and the other rare gases have closed electron shells and therefore remain montomic, even when they solidify. Their simple structure makes it likely that any measured change in conductivity is due to changes in the atomic structure, not in molecular configuration. As the crystal is compressed the band gap closes, allowing increased conductivity. We have begun research to determine the conductivity at high pressures, and it is our intention to determine the compression at which the crystal becomes a metal.

  16. The compressible mixing layer

    NASA Technical Reports Server (NTRS)

    Vandromme, Dany; Haminh, Hieu

    1991-01-01

    The capability of turbulence modeling correctly to handle natural unsteadiness appearing in compressible turbulent flows is investigated. Physical aspects linked to the unsteadiness problem and the role of various flow parameters are analyzed. It is found that unsteady turbulent flows can be simulated by dividing these motions into an 'organized' part for which equations of motion are solved and a remaining 'incoherent' part represented by a turbulence model. Two-equation turbulence models and second-order turbulence models can yield reasonable results. For specific compressible unsteady turbulent flow, graphic presentations of different quantities may reveal complementary physical features. Strong compression zones are observed in rapid flow parts but shocklets do not yet occur.

  17. Nonconvex compressive video sensing

    NASA Astrophysics Data System (ADS)

    Chen, Liangliang; Yan, Ming; Qian, Chunqi; Xi, Ning; Zhou, Zhanxin; Yang, Yongliang; Song, Bo; Dong, Lixin

    2016-11-01

    High-speed cameras explore more details than normal cameras in the time sequence, while the conventional video sampling suffers from the trade-off between temporal and spatial resolutions due to the sensor's physical limitation. Compressive sensing overcomes this obstacle by combining the sampling and compression procedures together. A single-pixel-based real-time video acquisition is proposed to record dynamic scenes, and a fast nonconvex algorithm for the nonconvex sorted ℓ1 regularization is applied to reconstruct frame differences using few numbers of measurements. Then, an edge-detection-based denoising method is employed to reduce the error in the frame difference image. The experimental results show that the proposed algorithm together with the single-pixel imaging system makes compressive video cameras available.

  18. Image compression for dermatology

    NASA Astrophysics Data System (ADS)

    Cookson, John P.; Sneiderman, Charles; Colaianni, Joseph; Hood, Antoinette F.

    1990-07-01

    Color 35mm photographic slides are commonly used in dermatology for education, and patient records. An electronic storage and retrieval system for digitized slide images may offer some advantages such as preservation and random access. We have integrated a system based on a personal computer (PC) for digital imaging of 35mm slides that depict dermatologic conditions. Such systems require significant resources to accommodate the large image files involved. Methods to reduce storage requirements and access time through image compression are therefore of interest. This paper contains an evaluation of one such compression method that uses the Hadamard transform implemented on a PC-resident graphics processor. Image quality is assessed by determining the effect of compression on the performance of an image feature recognition task.

  19. Compressible Flow Toolbox

    NASA Technical Reports Server (NTRS)

    Melcher, Kevin J.

    2006-01-01

    The Compressible Flow Toolbox is primarily a MATLAB-language implementation of a set of algorithms that solve approximately 280 linear and nonlinear classical equations for compressible flow. The toolbox is useful for analysis of one-dimensional steady flow with either constant entropy, friction, heat transfer, or Mach number greater than 1. The toolbox also contains algorithms for comparing and validating the equation-solving algorithms against solutions previously published in open literature. The classical equations solved by the Compressible Flow Toolbox are as follows: The isentropic-flow equations, The Fanno flow equations (pertaining to flow of an ideal gas in a pipe with friction), The Rayleigh flow equations (pertaining to frictionless flow of an ideal gas, with heat transfer, in a pipe of constant cross section), The normal-shock equations, The oblique-shock equations, and The expansion equations.

  20. Air blast type coal slurry fuel injector

    DOEpatents

    Phatak, R.G.

    1984-08-31

    A device to atomize and inject a coal slurry in the combustion chamber of an internal combustion engine is disclosed which eliminates the use of a conventional fuel injection pump/nozzle. The injector involves the use of compressed air to atomize and inject the coal slurry and like fuels. In one embodiment, the breaking and atomization of the fuel is achieved with the help of perforated discs and compressed air. In another embodiment, a cone shaped aspirator is used to achieve the breaking and atomization of the fuel. The compressed air protects critical bearing areas of the injector.

  1. Air blast type coal slurry fuel injector

    DOEpatents

    Phatak, Ramkrishna G.

    1986-01-01

    A device to atomize and inject a coal slurry in the combustion chamber of an internal combustion engine, and which eliminates the use of a conventional fuel injection pump/nozzle. The injector involves the use of compressed air to atomize and inject the coal slurry and like fuels. In one embodiment, the breaking and atomization of the fuel is achieved with the help of perforated discs and compressed air. In another embodiment, a cone shaped aspirator is used to achieve the breaking and atomization of the fuel. The compressed air protects critical bearing areas of the injector.

  2. Image data compression investigation

    NASA Technical Reports Server (NTRS)

    Myrie, Carlos

    1989-01-01

    NASA continuous communications systems growth has increased the demand for image transmission and storage. Research and analysis was conducted on various lossy and lossless advanced data compression techniques or approaches used to improve the efficiency of transmission and storage of high volume stellite image data such as pulse code modulation (PCM), differential PCM (DPCM), transform coding, hybrid coding, interframe coding, and adaptive technique. In this presentation, the fundamentals of image data compression utilizing two techniques which are pulse code modulation (PCM) and differential PCM (DPCM) are presented along with an application utilizing these two coding techniques.

  3. Isentropic compression of argon

    SciTech Connect

    Veeser, L.R.; Ekdahl, C.A.; Oona, H.

    1997-06-01

    The compression was done in an MC-1 flux compression (explosive) generator, in order to study the transition from an insulator to a conductor. Since conductivity signals were observed in all the experiments (except when the probe is removed), both the Teflon and the argon are becoming conductive. The conductivity could not be determined (Teflon insulation properties unknown), but it could be bounded as being {sigma}=1/{rho}{le}8({Omega}cm){sub -1}, because when the Teflon breaks down, the dielectric constant is reduced. The Teflon insulator problem remains, and other ways to better insulate the probe or to measure the conductivity without a probe is being sought.

  4. Homogenous charge compression ignition engine having a cylinder including a high compression space

    DOEpatents

    Agama, Jorge R.; Fiveland, Scott B.; Maloney, Ronald P.; Faletti, James J.; Clarke, John M.

    2003-12-30

    The present invention relates generally to the field of homogeneous charge compression engines. In these engines, fuel is injected upstream or directly into the cylinder when the power piston is relatively close to its bottom dead center position. The fuel mixes with air in the cylinder as the power piston advances to create a relatively lean homogeneous mixture that preferably ignites when the power piston is relatively close to the top dead center position. However, if the ignition event occurs either earlier or later than desired, lowered performance, engine misfire, or even engine damage, can result. Thus, the present invention divides the homogeneous charge between a controlled volume higher compression space and a lower compression space to better control the start of ignition.

  5. 29 CFR 1917.155 - Air receivers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Air receivers. 1917.155 Section 1917.155 Labor Regulations...) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.155 Air receivers. (a) Application. This section applies to compressed air receivers and equipment used for operations such as...

  6. 29 CFR 1926.306 - Air receivers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Air receivers. 1926.306 Section 1926.306 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.306 Air receivers. (a) General requirements—(1) Application. This section applies to compressed air receivers, and other equipment used...

  7. 29 CFR 1926.306 - Air receivers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Air receivers. 1926.306 Section 1926.306 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.306 Air receivers. (a) General requirements—(1) Application. This section applies to compressed air receivers, and other equipment used...

  8. 29 CFR 1917.155 - Air receivers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Air receivers. 1917.155 Section 1917.155 Labor Regulations...) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.155 Air receivers. (a) Application. This section applies to compressed air receivers and equipment used for operations such as...

  9. 29 CFR 1926.306 - Air receivers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Air receivers. 1926.306 Section 1926.306 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.306 Air receivers. (a) General requirements—(1) Application. This section applies to compressed air receivers, and other equipment used...

  10. 29 CFR 1926.306 - Air receivers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 8 2013-07-01 2013-07-01 false Air receivers. 1926.306 Section 1926.306 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.306 Air receivers. (a) General requirements—(1) Application. This section applies to compressed air receivers, and other equipment used...

  11. 29 CFR 1917.155 - Air receivers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Air receivers. 1917.155 Section 1917.155 Labor Regulations...) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.155 Air receivers. (a) Application. This section applies to compressed air receivers and equipment used for operations such as...

  12. 29 CFR 1926.306 - Air receivers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false Air receivers. 1926.306 Section 1926.306 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.306 Air receivers. (a) General requirements—(1) Application. This section applies to compressed air receivers, and other equipment used...

  13. 29 CFR 1917.155 - Air receivers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Air receivers. 1917.155 Section 1917.155 Labor Regulations...) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.155 Air receivers. (a) Application. This section applies to compressed air receivers and equipment used for operations such as...

  14. 29 CFR 1917.155 - Air receivers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Air receivers. 1917.155 Section 1917.155 Labor Regulations...) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.155 Air receivers. (a) Application. This section applies to compressed air receivers and equipment used for operations such as...

  15. 40 CFR 89.326 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Emission Test Equipment Provisions § 89.326 Engine intake air humidity measurement. (a) Humidity conditioned air...

  16. Equations, tables, and charts for compressible flow

    NASA Technical Reports Server (NTRS)

    1953-01-01

    This report, which is a revision and extension of NACA-TN-1428, presents a compilation of equations, tables, and charts useful in the analysis of high-speed flow of a compressible fluid. The equations provide relations for continuous one-dimensional flow, normal and oblique shock waves, and Prandtl-Meyer expansions for both perfect and imperfect gases. The tables present useful dimensionless ratios for continuous one-dimensional flow and for normal shock waves as functions of Mach number for air considered as a perfect gas. One series of charts presents the characteristics of the flow of air (considered a perfect gas) for oblique shock waves and for cones in a supersonic air stream. A second series shows the effects of caloric imperfections on continuous one-dimensional flow and on the flow through normal and oblique shock waves. (author)

  17. Field calibration of two types of microphones in hyperbaric air

    NASA Astrophysics Data System (ADS)

    Smith, Paul F.; Carpenter, Susan; Green, John

    1990-01-01

    The response of two microphones, one a condenser microphone and the other a diaphragm-activated piezoelectric ceramic microphone, were measured in compressed air at pressures as great as 810 kilopascals (8 atmospheres). The response of each microphone was compared to that of a hydrophone operated in air as a microphone. The results show that the two types of microphone respond similarly to high ambient pressure. Both types are less sensitive to sound pressure in compressed air than in air at normal pressures, and the frequency responses of both microphones are altered. The results are useful in the analyses of ambient noise measurements done during experiments in compressed air.

  18. Nonlinear Frequency Compression

    PubMed Central

    Scollie, Susan; Glista, Danielle; Seelisch, Andreas

    2013-01-01

    Frequency lowering technologies offer an alternative amplification solution for severe to profound high frequency hearing losses. While frequency lowering technologies may improve audibility of high frequency sounds, the very nature of this processing can affect the perceived sound quality. This article reports the results from two studies that investigated the impact of a nonlinear frequency compression (NFC) algorithm on perceived sound quality. In the first study, the cutoff frequency and compression ratio parameters of the NFC algorithm were varied, and their effect on the speech quality was measured subjectively with 12 normal hearing adults, 12 normal hearing children, 13 hearing impaired adults, and 9 hearing impaired children. In the second study, 12 normal hearing and 8 hearing impaired adult listeners rated the quality of speech in quiet, speech in noise, and music after processing with a different set of NFC parameters. Results showed that the cutoff frequency parameter had more impact on sound quality ratings than the compression ratio, and that the hearing impaired adults were more tolerant to increased frequency compression than normal hearing adults. No statistically significant differences were found in the sound quality ratings of speech-in-noise and music stimuli processed through various NFC settings by hearing impaired listeners. These findings suggest that there may be an acceptable range of NFC settings for hearing impaired individuals where sound quality is not adversely affected. These results may assist an Audiologist in clinical NFC hearing aid fittings for achieving a balance between high frequency audibility and sound quality. PMID:23539261

  19. Centrifugal Gas Compression Cycle

    NASA Astrophysics Data System (ADS)

    Fultun, Roy

    2002-11-01

    A centrifuged gas of kinetic, elastic hard spheres compresses isothermally and without flow of heat in a process that reverses free expansion. This theorem follows from stated assumptions via a collection of thought experiments, theorems and other supporting results, and it excludes application of the reversible mechanical adiabatic power law in this context. The existence of an isothermal adiabatic centrifugal compression process makes a three-process cycle possible using a fixed sample of the working gas. The three processes are: adiabatic mechanical expansion and cooling against a piston, isothermal adiabatic centrifugal compression back to the original volume, and isochoric temperature rise back to the original temperature due to an influx of heat. This cycle forms the basis for a Thomson perpetuum mobile that induces a loop of energy flow in an isolated system consisting of a heat bath connectable by a thermal path to the working gas, a mechanical extractor of the gas's internal energy, and a device that uses that mechanical energy and dissipates it as heat back into the heat bath. We present a simple experimental procedure to test the assertion that adiabatic centrifugal compression is isothermal. An energy budget for the cycle provides a criterion for breakeven in the conversion of heat to mechanical energy.

  20. The Compressed Video Experience.

    ERIC Educational Resources Information Center

    Weber, John

    In the fall semester 1995, Southern Arkansas University- Magnolia (SAU-M) began a two semester trial delivering college classes via a compressed video link between SAU-M and its sister school Southern Arkansas University Tech (SAU-T) in Camden. As soon as the University began broadcasting and receiving classes, it was discovered that using the…

  1. Compress Your Files

    ERIC Educational Resources Information Center

    Branzburg, Jeffrey

    2005-01-01

    File compression enables data to be squeezed together, greatly reducing file size. Why would someone want to do this? Reducing file size enables the sending and receiving of files over the Internet more quickly, the ability to store more files on the hard drive, and the ability pack many related files into one archive (for example, all files…

  2. Compress Your Files

    ERIC Educational Resources Information Center

    Branzburg, Jeffrey

    2005-01-01

    File compression enables data to be squeezed together, greatly reducing file size. Why would someone want to do this? Reducing file size enables the sending and receiving of files over the Internet more quickly, the ability to store more files on the hard drive, and the ability pack many related files into one archive (for example, all files…

  3. Focus on Compression Stockings

    MedlinePlus

    ... soap. Do not use Woolite™ detergent. Use warm water and wash by hand or in the gentle cycle in the washing machine. After rinsing the compression stocking completely, remove excess water by rolling it in a ... the dryer on the deli- cate cycle at a cool temperature. It may be convenient ...

  4. Closed-loop air cooling system for a turbine engine

    DOEpatents

    North, William Edward

    2000-01-01

    Method and apparatus are disclosed for providing a closed-loop air cooling system for a turbine engine. The method and apparatus provide for bleeding pressurized air from a gas turbine engine compressor for use in cooling the turbine components. The compressed air is cascaded through the various stages of the turbine. At each stage a portion of the compressed air is returned to the compressor where useful work is recovered.

  5. TEM Video Compressive Sensing

    SciTech Connect

    Stevens, Andrew J.; Kovarik, Libor; Abellan, Patricia; Yuan, Xin; Carin, Lawrence; Browning, Nigel D.

    2015-08-02

    One of the main limitations of imaging at high spatial and temporal resolution during in-situ TEM experiments is the frame rate of the camera being used to image the dynamic process. While the recent development of direct detectors has provided the hardware to achieve frame rates approaching 0.1ms, the cameras are expensive and must replace existing detectors. In this paper, we examine the use of coded aperture compressive sensing methods [1, 2, 3, 4] to increase the framerate of any camera with simple, low-cost hardware modifications. The coded aperture approach allows multiple sub-frames to be coded and integrated into a single camera frame during the acquisition process, and then extracted upon readout using statistical compressive sensing inversion. Our simulations show that it should be possible to increase the speed of any camera by at least an order of magnitude. Compressive Sensing (CS) combines sensing and compression in one operation, and thus provides an approach that could further improve the temporal resolution while correspondingly reducing the electron dose rate. Because the signal is measured in a compressive manner, fewer total measurements are required. When applied to TEM video capture, compressive imaging couled improve acquisition speed and reduce the electron dose rate. CS is a recent concept, and has come to the forefront due the seminal work of Candès [5]. Since the publication of Candès, there has been enormous growth in the application of CS and development of CS variants. For electron microscopy applications, the concept of CS has also been recently applied to electron tomography [6], and reduction of electron dose in scanning transmission electron microscopy (STEM) imaging [7]. To demonstrate the applicability of coded aperture CS video reconstruction for atomic level imaging, we simulate compressive sensing on observations of Pd nanoparticles and Ag nanoparticles during exposure to high temperatures and other environmental

  6. Multimode Data-Compression System

    NASA Technical Reports Server (NTRS)

    Fang, Wai-Chi

    1996-01-01

    Data-compression system developed to satisfy need for high-speed, high-performance compression of data from sources as diverse as medical images, high-definition television images, audio signals, readouts from scientific instruments, and binary data files. Maximum data-transmission capability of communication channel or storage capacity of storage device multiplied by approximately compression ratio. Various combinations of lossless and lossy compression chosen to suit various data streams.

  7. Multimode Data-Compression System

    NASA Technical Reports Server (NTRS)

    Fang, Wai-Chi

    1996-01-01

    Data-compression system developed to satisfy need for high-speed, high-performance compression of data from sources as diverse as medical images, high-definition television images, audio signals, readouts from scientific instruments, and binary data files. Maximum data-transmission capability of communication channel or storage capacity of storage device multiplied by approximately compression ratio. Various combinations of lossless and lossy compression chosen to suit various data streams.

  8. Progressive transmission and compression images

    NASA Technical Reports Server (NTRS)

    Kiely, A. B.

    1996-01-01

    We describe an image data compression strategy featuring progressive transmission. The method exploits subband coding and arithmetic coding for compression. We analyze the Laplacian probability density, which closely approximates the statistics of individual subbands, to determine a strategy for ordering the compressed subband data in a way that improves rate-distortion performance. Results are presented for a test image.

  9. Space-time compressive imaging.

    PubMed

    Treeaporn, Vicha; Ashok, Amit; Neifeld, Mark A

    2012-02-01

    Compressive imaging systems typically exploit the spatial correlation of the scene to facilitate a lower dimensional measurement relative to a conventional imaging system. In natural time-varying scenes there is a high degree of temporal correlation that may also be exploited to further reduce the number of measurements. In this work we analyze space-time compressive imaging using Karhunen-Loève (KL) projections for the read-noise-limited measurement case. Based on a comprehensive simulation study, we show that a KL-based space-time compressive imager offers higher compression relative to space-only compressive imaging. For a relative noise strength of 10% and reconstruction error of 10%, we find that space-time compressive imaging with 8×8×16 spatiotemporal blocks yields about 292× compression compared to a conventional imager, while space-only compressive imaging provides only 32× compression. Additionally, under high read-noise conditions, a space-time compressive imaging system yields lower reconstruction error than a conventional imaging system due to the multiplexing advantage. We also discuss three electro-optic space-time compressive imaging architecture classes, including charge-domain processing by a smart focal plane array (FPA). Space-time compressive imaging using a smart FPA provides an alternative method to capture the nonredundant portions of time-varying scenes.

  10. Predictive Encoding in Text Compression.

    ERIC Educational Resources Information Center

    Raita, Timo; Teuhola, Jukka

    1989-01-01

    Presents three text compression methods of increasing power and evaluates each based on the trade-off between compression gain and processing time. The advantages of using hash coding for speed and optimal arithmetic coding to successor information for compression gain are discussed. (26 references) (Author/CLB)

  11. Digital cinema video compression

    NASA Astrophysics Data System (ADS)

    Husak, Walter

    2003-05-01

    The Motion Picture Industry began a transition from film based distribution and projection to digital distribution and projection several years ago. Digital delivery and presentation offers the prospect to increase the quality of the theatrical experience for the audience, reduce distribution costs to the distributors, and create new business opportunities for the theater owners and the studios. Digital Cinema also presents an opportunity to provide increased flexibility and security of the movies for the content owners and the theater operators. Distribution of content via electronic means to theaters is unlike any of the traditional applications for video compression. The transition from film-based media to electronic media represents a paradigm shift in video compression techniques and applications that will be discussed in this paper.

  12. Method and apparatus for extracting water from air

    DOEpatents

    Spletzer, Barry L.; Callow, Diane Schafer; Marron, Lisa C.; Salton, Jonathan R.

    2002-01-01

    The present invention provides a method and apparatus for extracting liquid water from moist air using minimal energy input. The method comprises compressing moist air under conditions that foster the condensation of liquid water. The air can be decompressed under conditions that do not foster the vaporization of the condensate. The decompressed, dried air can be exchanged for a fresh charge of moist air and the process repeated. The liquid condensate can be removed for use. The apparatus can comprise a compression chamber having a variable internal volume. An intake port allows moist air into the compression chamber. An exhaust port allows dried air out of the compression chamber. A condensation device fosters condensation at the desired conditions. A condensate removal port allows liquid water to be removed.

  13. Method and apparatus for extracting water from air

    DOEpatents

    Spletzer, Barry L.

    2001-01-01

    The present invention provides a method and apparatus for extracting liquid water from moist air using minimal energy input. The method comprises compressing moist air under conditions that foster the condensation of liquid water (ideally isothermal to a humidity of 1.0, then adiabatic thereafter). The air can be decompressed under conditions that do not foster the vaporization of the condensate. The decompressed, dried air can be exchanged for a fresh charge of moist air and the process repeated. The liquid condensate can be removed for use. The apparatus can comprise a compression chamber having a variable internal volume. An intake port allows moist air into the compression chamber. An exhaust port allows dried air out of the compression chamber. A condensation device fosters condensation at the desired conditions. A condensate removal port allows liquid water to be removed.

  14. Method and apparatus for extracting water from air

    DOEpatents

    Spletzer, Barry L.; Callow, Diane Schafer; Marron, Lisa C.; Salton, Jonathan R.

    2002-01-01

    The present invention provides a method and apparatus for extracting liquid water from moist air using minimal energy input. The method comprises compressing moist air under conditions that foster the condensation of liquid water. The air can be decompressed under conditions that do not foster the vaporization of the condensate. The decompressed, dried air can be exchanged for a fresh charge of moist air and the process repeated. The liquid condensate can be removed for use. The apparatus can comprise a compression chamber having a variable internal volume. An intake port allows moist air into the compression chamber. An exhaust port allows dried air out of the compression chamber. A condensation device fosters condensation at the desired conditions. A condensate removal port allows liquid water to be removed.

  15. Mammographic compression in Asian women

    PubMed Central

    Lau, Susie; Abdul Aziz, Yang Faridah; Ng, Kwan Hoong

    2017-01-01

    Objectives To investigate: (1) the variability of mammographic compression parameters amongst Asian women; and (2) the effects of reducing compression force on image quality and mean glandular dose (MGD) in Asian women based on phantom study. Methods We retrospectively collected 15818 raw digital mammograms from 3772 Asian women aged 35–80 years who underwent screening or diagnostic mammography between Jan 2012 and Dec 2014 at our center. The mammograms were processed using a volumetric breast density (VBD) measurement software (Volpara) to assess compression force, compression pressure, compressed breast thickness (CBT), breast volume, VBD and MGD against breast contact area. The effects of reducing compression force on image quality and MGD were also evaluated based on measurement obtained from 105 Asian women, as well as using the RMI156 Mammographic Accreditation Phantom and polymethyl methacrylate (PMMA) slabs. Results Compression force, compression pressure, CBT, breast volume, VBD and MGD correlated significantly with breast contact area (p<0.0001). Compression parameters including compression force, compression pressure, CBT and breast contact area were widely variable between [relative standard deviation (RSD)≥21.0%] and within (p<0.0001) Asian women. The median compression force should be about 8.1 daN compared to the current 12.0 daN. Decreasing compression force from 12.0 daN to 9.0 daN increased CBT by 3.3±1.4 mm, MGD by 6.2–11.0%, and caused no significant effects on image quality (p>0.05). Conclusions Force-standardized protocol led to widely variable compression parameters in Asian women. Based on phantom study, it is feasible to reduce compression force up to 32.5% with minimal effects on image quality and MGD. PMID:28419125

  16. Compressibility of solids

    NASA Technical Reports Server (NTRS)

    Vinet, P.; Ferrante, J.; Rose, J. H.; Smith, J. R.

    1987-01-01

    A universal form is proposed for the equation of state (EOS) of solids. Good agreement is found for a variety of test data. The form of the EOS is used to suggest a method of data analysis, which is applied to materials of geophysical interest. The isothermal bulk modulus is discussed as a function of the volume and of the pressure. The isothermal compression curves for materials of geophysical interest are examined.

  17. Basic cluster compression algorithm

    NASA Technical Reports Server (NTRS)

    Hilbert, E. E.; Lee, J.

    1980-01-01

    Feature extraction and data compression of LANDSAT data is accomplished by BCCA program which reduces costs associated with transmitting, storing, distributing, and interpreting multispectral image data. Algorithm uses spatially local clustering to extract features from image data to describe spectral characteristics of data set. Approach requires only simple repetitive computations, and parallel processing can be used for very high data rates. Program is written in FORTRAN IV for batch execution and has been implemented on SEL 32/55.

  18. Beamforming Using Compressive Sensing

    DTIC Science & Technology

    2011-10-01

    Am. 130 (4), October 2011 VC 2011 Acoustical Society of America G. F. Edelmann and C. F. Gaumond: JASA Express Letters [DOI: 10.1121/1.3632046...arbitrarily spaced array, the rank of A may be insufficient, G. F. Edelmann and C. F. Gaumond: JASA Express Letters [DOI: 10.1121/1.3632046] Published Online...09 September 2011 J. Acoust. Soc. Am. 130 (4), October 2011 G. F. Edelmann and C. F. Gaumond: Beamforming using compressive sensing EL233 Downloaded

  19. Shock compression of nitrobenzene

    NASA Astrophysics Data System (ADS)

    Kozu, Naoshi; Arai, Mitsuru; Tamura, Masamitsu; Fujihisa, Hiroshi; Aoki, Katsutoshi; Yoshida, Masatake; Kondo, Ken-Ichi

    1999-06-01

    The Hugoniot (4 - 30 GPa) and the isotherm (1 - 7 GPa) of nitrobenzene have been investigated by shock and static compression experiments. Nitrobenzene has the most basic structure of nitro aromatic compounds, which are widely used as energetic materials, but nitrobenzene has been considered not to explode in spite of the fact its calculated heat of detonation is similar to TNT, about 1 kcal/g. Explosive plane-wave generators and diamond anvil cell were used for shock and static compression, respectively. The obtained Hugoniot consists of two linear lines, and the kink exists around 10 GPa. The upper line agrees well with the Hugoniot of detonation products calculated by KHT code, so it is expected that nitrobenzene detonates in that area. Nitrobenzene solidifies under 1 GPa of static compression, and the isotherm of solid nitrobenzene was obtained by X-ray diffraction technique. Comparing the Hugoniot and the isotherm, nitrobenzene is in liquid phase under experimented shock condition. From the expected phase diagram, shocked nitrobenzene seems to remain metastable liquid in solid phase region on that diagram.

  20. Compression of Cake

    NASA Astrophysics Data System (ADS)

    Nason, Sarah; Houghton, Brittany; Renfro, Timothy

    2012-03-01

    The fall university physics class, at McMurry University, created a compression modulus experiment that even high school students could do. The class came up with this idea after a Young's modulus experiment which involved stretching wire. A question was raised of what would happen if we compressed something else? We created our own Young's modulus experiment, but in a more entertaining way. The experiment involves measuring the height of a cake both before and after a weight has been applied to the cake. We worked to derive the compression modulus by applying weight to a cake. In the end, we had our experimental cake and, ate it too! To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2012.TSS.B1.1

  1. Compression therapy for venous disease.

    PubMed

    Attaran, Robert R; Ochoa Chaar, Cassius I

    2017-03-01

    For centuries, compression therapy has been utilized to treat venous disease. To date it remains the mainstay of therapy, particularly in more severe forms such as venous ulceration. In addition to mechanisms of benefit, we discuss the evidence behind compression therapy, particularly hosiery, in various forms of venous disease of the lower extremities. We review compression data for stand-alone therapy, post-intervention, as DVT prevention, post-thrombotic syndrome and venous ulcer disease. We also review the data comparing compression modalities as well as the use of compression in mixed arteriovenous disease.

  2. Performance Enhancement Technology for the Vapor Compression Refrigeration Cycle

    NASA Astrophysics Data System (ADS)

    Man'o, Tatsunori

    High efficiency refrigerator have been developed. For energy saving that is concerned with against global warming, performance enhancement of vapor compression refrigerator is required in field of air condition and refrigeration facility. In this paper, a review of recent performance enhancement technologies for the vapor compression refrigeration cycle is presented. This review contains high performance cycles of large sized centrifugal chiller, small to middle sized chiller and packaged air conditioner. Moreover, researches and developments of the refrigeration cycle recovering throttling loss, applications of ejector to boost in compressor suction pressure and to recirculate vapor refrigerant in the evaporator for heat transfer enhancement, and applications of expander to employ expansion work for compression work, are reviewed.

  3. 10. DIAMOND MINE YARD FROM THE NORTH SHOWING A COMPRESSED ...

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

    10. DIAMOND MINE YARD FROM THE NORTH SHOWING A COMPRESSED AIR PIPE AND TRESTLE IN THE LOWER LEFT, AND THE LORRY HOUSE. A PART OF A RETAINING WALL IS VISIBLE ABOVE THE RAILROAD CUT - Butte Mineyards, Diamond Mine, Butte, Silver Bow County, MT

  4. [Compression therapy in leg ulcers].

    PubMed

    Dissemond, J; Protz, K; Reich-Schupke, S; Stücker, M; Kröger, K

    2016-04-01

    Compression therapy is well-tried treatment with only few side effects for most patients with leg ulcers and/or edema. Despite the very long tradition in German-speaking countries and good evidence for compression therapy in different indications, recent scientific findings indicate that the current situation in Germany is unsatisfactory. Today, compression therapy can be performed with very different materials and systems. In addition to the traditional bandaging with Unna Boot, short-stretch, long-stretch, or multicomponent bandage systems, medical compression ulcer stockings are available. Other very effective but far less common alternatives are velcro wrap systems. When planning compression therapy, it is also important to consider donning devices with the patient. In addition to compression therapy, intermittent pneumatic compression therapy can be used. Through these various treatment options, it is now possible to develop an individually accepted, geared to the needs of the patients, and functional therapy strategy for nearly all patients with leg ulcers.

  5. 30 CFR 56.13012 - Compressor air intakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Compressor air intakes. 56.13012 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13012 Compressor air intakes. Compressor air intakes shall be installed to ensure that...

  6. 21 CFR 868.6250 - Portable air compressor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Portable air compressor. 868.6250 Section 868.6250...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6250 Portable air compressor. (a) Identification. A portable air compressor is a device intended to provide compressed air for medical purposes,...

  7. 21 CFR 868.6250 - Portable air compressor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Portable air compressor. 868.6250 Section 868.6250...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6250 Portable air compressor. (a) Identification. A portable air compressor is a device intended to provide compressed air for medical purposes,...

  8. 30 CFR 57.13011 - Air receiver tanks.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Air receiver tanks. 57.13011 Section 57.13011... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13011 Air receiver tanks. Air receiver tanks shall be equipped with one or more...

  9. 21 CFR 868.6250 - Portable air compressor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Portable air compressor. 868.6250 Section 868.6250...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6250 Portable air compressor. (a) Identification. A portable air compressor is a device intended to provide compressed air for medical purposes,...

  10. 21 CFR 868.6250 - Portable air compressor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Portable air compressor. 868.6250 Section 868.6250...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Miscellaneous § 868.6250 Portable air compressor. (a) Identification. A portable air compressor is a device intended to provide compressed air for medical purposes,...

  11. 30 CFR 56.13012 - Compressor air intakes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Compressor air intakes. 56.13012 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13012 Compressor air intakes. Compressor air intakes shall be installed to ensure that...

  12. 30 CFR 56.13011 - Air receiver tanks.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Air receiver tanks. 56.13011 Section 56.13011... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13011 Air receiver tanks. Air receiver tanks shall be equipped with one or more automatic...

  13. 30 CFR 56.13011 - Air receiver tanks.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Air receiver tanks. 56.13011 Section 56.13011... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13011 Air receiver tanks. Air receiver tanks shall be equipped with one or more automatic...

  14. 30 CFR 57.13012 - Compressor air intakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Compressor air intakes. 57.13012 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13012 Compressor air intakes. Compressor air intakes shall be installed to...

  15. 30 CFR 56.13010 - Reciprocating-type air compressors.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air...

  16. 30 CFR 57.13011 - Air receiver tanks.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Air receiver tanks. 57.13011 Section 57.13011... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13011 Air receiver tanks. Air receiver tanks shall be equipped with one or more...

  17. 30 CFR 56.13010 - Reciprocating-type air compressors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air...

  18. 30 CFR 56.13012 - Compressor air intakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Compressor air intakes. 56.13012 Section 56... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13012 Compressor air intakes. Compressor air intakes shall be installed to ensure that...

  19. 30 CFR 56.13010 - Reciprocating-type air compressors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Reciprocating-type air compressors. 56.13010... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air...

  20. 30 CFR 57.13012 - Compressor air intakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Compressor air intakes. 57.13012 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13012 Compressor air intakes. Compressor air intakes shall be installed to...

  1. 30 CFR 56.13011 - Air receiver tanks.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Air receiver tanks. 56.13011 Section 56.13011... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13011 Air receiver tanks. Air receiver tanks shall be equipped with one or more automatic...

  2. Air Research

    EPA Pesticide Factsheets

    EPA's air research provides the critical science to develop and implement outdoor air regulations under the Clean Air Act and puts new tools and information in the hands of air quality managers and regulators to protect the air we breathe.

  3. Compressibility and Heating Effects on Pressure Loss and Cooling of a Baffled Cylinder Barrel

    NASA Technical Reports Server (NTRS)

    Goldstein, Arthur W.; Ellerbrock, Herman H., Jr.

    1944-01-01

    Theoretical investigations have shown that, because air is compressible, the pressure-drop requirements for cooling an air-cooled engine will be much greater at high altitudes and high speeds than at sea level and low speeds. Tests were conducted by the NACA to obtain some experimental confirmation of the effect of air compressibility on cooling and pressure loss of a baffled cylinder barrel and to evaluate various methods of analysis. The results reported in the present paper are regarded as preliminary to tests on single-cylinder and multi-cylinder engines. Tests were conducted over a wide range of air flows and density altitudes.

  4. Compressibility and Heating Effects on Pressure Loss and Cooling of a Baffled Cylinder Barrel

    NASA Technical Reports Server (NTRS)

    Goldstein, Arthur W; Ellerbrock, Herman H , Jr

    1944-01-01

    Theoretical investigations have shown that, because air is compressible, the pressure-drop requirements for cooling an air-cooled engine will be much greater at high altitudes and high speeds than at sea level and low speeds. Tests were conducted by the NACA to obtain some experimental confirmation of the effect of air compressibility on cooling and pressure loss of a baffled cylinder barrel and to evaluate various methods of analysis. The results reported in the present paper are regarded as preliminary to tests on single-cylinder and multicylinder engines. Tests were conducted over a wide range of air flows and density altitudes.

  5. Temporal solitons in air

    NASA Astrophysics Data System (ADS)

    Voronin, A. A.; Zheltikov, A. M.

    2017-02-01

    Analysis of the group-velocity dispersion (GVD) of atmospheric air with a model that includes the entire manifold of infrared transitions in air reveals a remarkably broad and continuous anomalous-GVD region in the high-frequency wing of the carbon dioxide rovibrational band from approximately 3.5 to 4.2 μm where atmospheric air is still highly transparent and where high-peak-power sources of ultrashort midinfrared pulses are available. Within this range, anomalous dispersion acting jointly with optical nonlinearity of atmospheric air is shown to give rise to a unique three-dimensional dynamics with well-resolved soliton features in the time domain, enabling a highly efficient whole-beam soliton self-compression of such pulses to few-cycle pulse widths.

  6. Comparative data compression techniques and multi-compression results

    NASA Astrophysics Data System (ADS)

    Hasan, M. R.; Ibrahimy, M. I.; Motakabber, S. M. A.; Ferdaus, M. M.; Khan, M. N. H.

    2013-12-01

    Data compression is very necessary in business data processing, because of the cost savings that it offers and the large volume of data manipulated in many business applications. It is a method or system for transmitting a digital image (i.e., an array of pixels) from a digital data source to a digital data receiver. More the size of the data be smaller, it provides better transmission speed and saves time. In this communication, we always want to transmit data efficiently and noise freely. This paper will provide some compression techniques for lossless text type data compression and comparative result of multiple and single compression, that will help to find out better compression output and to develop compression algorithms.

  7. SeqCompress: an algorithm for biological sequence compression.

    PubMed

    Sardaraz, Muhammad; Tahir, Muhammad; Ikram, Ataul Aziz; Bajwa, Hassan

    2014-10-01

    The growth of Next Generation Sequencing technologies presents significant research challenges, specifically to design bioinformatics tools that handle massive amount of data efficiently. Biological sequence data storage cost has become a noticeable proportion of total cost in the generation and analysis. Particularly increase in DNA sequencing rate is significantly outstripping the rate of increase in disk storage capacity, which may go beyond the limit of storage capacity. It is essential to develop algorithms that handle large data sets via better memory management. This article presents a DNA sequence compression algorithm SeqCompress that copes with the space complexity of biological sequences. The algorithm is based on lossless data compression and uses statistical model as well as arithmetic coding to compress DNA sequences. The proposed algorithm is compared with recent specialized compression tools for biological sequences. Experimental results show that proposed algorithm has better compression gain as compared to other existing algorithms.

  8. Ultrasound beamforming using compressed data.

    PubMed

    Li, Yen-Feng; Li, Pai-Chi

    2012-05-01

    The rapid advancements in electronics technologies have made software-based beamformers for ultrasound array imaging feasible, thus facilitating the rapid development of high-performance and potentially low-cost systems. However, one challenge to realizing a fully software-based system is transferring data from the analog front end to the software back end at rates of up to a few gigabits per second. This study investigated the use of data compression to reduce the data transfer requirements and optimize the associated trade-off with beamforming quality. JPEG and JPEG2000 compression techniques were adopted. The acoustic data of a line phantom were acquired with a 128-channel array transducer at a center frequency of 3.5 MHz, and the acoustic data of a cyst phantom were acquired with a 64-channel array transducer at a center frequency of 3.33 MHz. The receive-channel data associated with each transmit event are separated into 8 × 8 blocks and several tiles before JPEG and JPEG2000 data compression is applied, respectively. In one scheme, the compression was applied to raw RF data, while in another only the amplitude of baseband data was compressed. The maximum compression ratio of RF data compression to produce an average error of lower than 5 dB was 15 with JPEG compression and 20 with JPEG2000 compression. The image quality is higher with baseband amplitude data compression than with RF data compression; although the maximum overall compression ratio (compared with the original RF data size), which was limited by the data size of uncompressed phase data, was lower than 12, the average error in this case was lower than 1 dB when the compression ratio was lower than 8.

  9. The compression of liquids

    NASA Astrophysics Data System (ADS)

    Whalley, E.

    The compression of liquids can be measured either directly by applying a pressure and noting the volume change, or indirectly, by measuring the magnitude of the fluctuations of the local volume. The methods used in Ottawa for the direct measurement of the compression are reviewed. The mean-square deviation of the volume from the mean at constant temperature can be measured by X-ray and neutron scattering at low angles, and the meansquare deviation at constant entropy can be measured by measuring the speed of sound. The speed of sound can be measured either acoustically, using an acoustic transducer, or by Brillouin spectroscopy. Brillouin spectroscopy can also be used to study the shear waves in liquids if the shear relaxation time is > ∼ 10 ps. The relaxation time of water is too short for the shear waves to be studied in this way, but they do occur in the low-frequency Raman and infrared spectra. The response of the structure of liquids to pressure can be studied by neutron scattering, and recently experiments have been done at Atomic Energy of Canada Ltd, Chalk River, on liquid D 2O up to 15.6 kbar. They show that the near-neighbor intermolecular O-D and D-D distances are less spread out and at shorter distances at high pressure. Raman spectroscopy can also provide information on the structural response. It seems that the O-O distance in water decreases much less with pressure than it does in ice. Presumably, the bending of O-O-O angles tends to increase the O-O distance, and so to largely compensate the compression due to the direct effect of pressure.

  10. International magnetic pulse compression

    NASA Astrophysics Data System (ADS)

    Kirbie, H. C.; Newton, M. A.; Siemens, P. D.

    1991-04-01

    Although pulsed-power engineering traditionally has been practiced by a fairly small, close community in the areas of defense and energy research, it is becoming more common in high-power, high-energy commercial pursuits such as material processing and lasers. This paper is a synopsis of the Feb. 12-14, 1990 workshop on magnetic switching as it applies primarily to pulse compression (power transformation). During the course of the Workshop at Granlibakken, a great deal of information was amassed and a keen insight into both the problems and opportunities as to the use of this switching approach was developed. The segmented workshop format proved ideal for identifying key aspects affecting optimum performance in a variety of applications. Individual groups of experts addressed network and system modeling, magnetic materials, power conditioning, core cooling and dielectrics, and finally circuits and application. At the end, they came together to consolidate their input and formulate the workshop's conclusions, identifying roadblocks or suggesting research projects, particularly as they apply to magnetic switching's trump card - its high-average-power-handling capability (at least on a burst-mode basis). The workshop was especially productive both in the quality and quantity of information transfer in an environment conducive to a free and open exchange of ideas. We will not delve into the organization proper of this meeting, rather we wish to commend to the interested reader this volume, which provides the definitive and most up-to-date compilation on the subject of magnetic pulse compression from underlying principles to current state of the art as well as the prognosis for the future of magnetic pulse compression as a consensus of the workshop's organizers and participants.

  11. International magnetic pulse compression

    SciTech Connect

    Kirbie, H.C.; Newton, M.A.; Siemens, P.D.

    1991-04-01

    Although pulsed-power engineering traditionally has been practiced by a fairly small, close community in the areas of defense and energy research, it is becoming more common in high-power, high-energy commercial pursuits such as material processing and lasers. This paper is a synopsis of the Feb. 12--14, 1990 workshop on magnetic switching as it applies primarily to pulse compression (power transformation). During the course of the Workshop at Granlibakken, a great deal of information was amassed and a keen insight into both the problems and opportunities as to the use of this switching approach was developed. The segmented workshop format proved ideal for identifying key aspects affecting optimum performance in a variety of applications. Individual groups of experts addressed network and system modeling, magnetic materials, power conditioning, core cooling and dielectrics, and finally circuits and application. At the end, they came together to consolidate their input and formulate the workshop's conclusions, identifying roadblocks or suggesting research projects, particularly as they apply to magnetic switching's trump card -- its high-average-power-handling capability (at least on a burst-mode basis). The workshop was especially productive both in the quality and quantity of information transfer in an environment conducive to a free and open exchange of ideas. We will not delve into the organization proper of this meeting, rather we wish to commend to the interested reader this volume, which provides the definitive and most up-to-date compilation on the subject of magnetic pulse compression from underlying principles to current state of the art as well as the prognosis for the future of magnetic pulse compression as a consensus of the workshop's organizers and participants.

  12. Compression retaining piston

    SciTech Connect

    Quaglino, A.V. Jr.

    1987-06-16

    A piston apparatus is described for maintaining compression between the piston wall and the cylinder wall, that comprises the following: a generally cylindrical piston body, including: a head portion defining the forward end of the body; and a continuous side wall portion extending rearward from the head portion; a means for lubricating and preventing compression loss between the side wall portion and the cylinder wall, including an annular recessed area in the continuous side wall portion for receiving a quantity of fluid lubricant in fluid engagement between the wall of the recessed and the wall of the cylinder; a first and second resilient, elastomeric, heat resistant rings positioned in grooves along the wall of the continuous side wall portion, above and below the annular recessed area. Each ring engages the cylinder wall to reduce loss of lubricant within the recessed area during operation of the piston; a first pump means for providing fluid lubricant to engine components other than the pistons; and a second pump means provides fluid lubricant to the recessed area in the continuous side wall portion of the piston. The first and second pump means obtains lubricant from a common source, and the second pump means including a flow line supplies oil from a predetermined level above the level of oil provided to the first pump means. This is so that should the oil level to the second pump means fall below the predetermined level, the loss of oil to the recessed area in the continuous side wall portion of the piston would result in loss of compression and shut down of the engine.

  13. Compressible magnetohydrodynamic sawtooth crash

    NASA Astrophysics Data System (ADS)

    Sugiyama, Linda E.

    2014-02-01

    In a toroidal magnetically confined plasma at low resistivity, compressible magnetohydrodynamic (MHD) predicts that an m = 1/n = 1 sawtooth has a fast, explosive crash phase with abrupt onset, rate nearly independent of resistivity, and localized temperature redistribution similar to experimental observations. Large scale numerical simulations show that the 1/1 MHD internal kink grows exponentially at a resistive rate until a critical amplitude, when the plasma motion accelerates rapidly, culminating in fast loss of the temperature and magnetic structure inside q < 1, with somewhat slower density redistribution. Nonlinearly, for small effective growth rate the perpendicular momentum rate of change remains small compared to its individual terms ∇p and J × B until the fast crash, so that the compressible growth rate is determined by higher order terms in a large aspect ratio expansion, as in the linear eigenmode. Reduced MHD fails completely to describe the toroidal mode; no Sweet-Parker-like reconnection layer develops. Important differences result from toroidal mode coupling effects. A set of large aspect ratio compressible MHD equations shows that the large aspect ratio expansion also breaks down in typical tokamaks with rq =1/Ro≃1/10 and a /Ro≃1/3. In the large aspect ratio limit, failure extends down to much smaller inverse aspect ratio, at growth rate scalings γ =O(ɛ2). Higher order aspect ratio terms, including B˜ϕ, become important. Nonlinearly, higher toroidal harmonics develop faster and to a greater degree than for large aspect ratio and help to accelerate the fast crash. The perpendicular momentum property applies to other transverse MHD instabilities, including m ≥ 2 magnetic islands and the plasma edge.

  14. Avalanches in Wood Compression

    NASA Astrophysics Data System (ADS)

    Mäkinen, T.; Miksic, A.; Ovaska, M.; Alava, Mikko J.

    2015-07-01

    Wood is a multiscale material exhibiting a complex viscoplastic response. We study avalanches in small wood samples in compression. "Woodquakes" measured by acoustic emission are surprisingly similar to earthquakes and crackling noise in rocks and laboratory tests on brittle materials. Both the distributions of event energies and of waiting (silent) times follow power laws. The stress-strain response exhibits clear signatures of localization of deformation to "weak spots" or softwood layers, as identified using digital image correlation. Even though material structure-dependent localization takes place, the avalanche behavior remains scale-free.

  15. Avalanches in Wood Compression.

    PubMed

    Mäkinen, T; Miksic, A; Ovaska, M; Alava, Mikko J

    2015-07-31

    Wood is a multiscale material exhibiting a complex viscoplastic response. We study avalanches in small wood samples in compression. "Woodquakes" measured by acoustic emission are surprisingly similar to earthquakes and crackling noise in rocks and laboratory tests on brittle materials. Both the distributions of event energies and of waiting (silent) times follow power laws. The stress-strain response exhibits clear signatures of localization of deformation to "weak spots" or softwood layers, as identified using digital image correlation. Even though material structure-dependent localization takes place, the avalanche behavior remains scale-free.

  16. Sampling video compression system

    NASA Technical Reports Server (NTRS)

    Matsumoto, Y.; Lum, H. (Inventor)

    1977-01-01

    A system for transmitting video signal of compressed bandwidth is described. The transmitting station is provided with circuitry for dividing a picture to be transmitted into a plurality of blocks containing a checkerboard pattern of picture elements. Video signals along corresponding diagonal rows of picture elements in the respective blocks are regularly sampled. A transmitter responsive to the output of the sampling circuitry is included for transmitting the sampled video signals of one frame at a reduced bandwidth over a communication channel. The receiving station is provided with a frame memory for temporarily storing transmitted video signals of one frame at the original high bandwidth frequency.

  17. Beamforming using compressive sensing.

    PubMed

    Edelmann, Geoffrey F; Gaumond, Charles F

    2011-10-01

    Compressive sensing (CS) is compared with conventional beamforming using horizontal beamforming of at-sea, towed-array data. They are compared qualitatively using bearing time records and quantitatively using signal-to-interference ratio. Qualitatively, CS exhibits lower levels of background interference than conventional beamforming. Furthermore, bearing time records show increasing, but tolerable, levels of background interference when the number of elements is decreased. For the full array, CS generates signal-to-interference ratio of 12 dB, but conventional beamforming only 8 dB. The superiority of CS over conventional beamforming is much more pronounced with undersampling.

  18. Image Compression Devices

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Rice algorithm is a "lossless" compression algorithm; it takes an image or other data that has been broken down into short strings of digital data, then processes each string mathematically to reduce the amount of memory required to store or transmit them. It is particularly useful in medical, scientific or engineering applications where all data must be preserved. Originally developed at Jet Propulsion Laboratory, the technology is marketed by Advanced Hardware Architectures, a company started by a former employee of the NASA Microelectronics Research Center.

  19. Compression and Entrapment Syndromes

    PubMed Central

    Heffernan, L.P.; Benstead, T.J.

    1987-01-01

    Family physicians are often confronted by patients who present with pain, numbness and weakness. Such complaints, when confined to a single extremity, most particularly to a restricted portion of the extremity, may indicate focal dysfunction of peripheral nerve structures arising from compression and/or entrapment, to which such nerves are selectively vulnerable. The authors of this article consider the paramount clinical features that allow the clinician to arrive at a correct diagnosis, reviews major points in differential diagnosis, and suggest appropriate management strategies. PMID:21263858

  20. Compressive full waveform lidar

    NASA Astrophysics Data System (ADS)

    Yang, Weiyi; Ke, Jun

    2017-05-01

    To avoid high bandwidth detector, fast speed A/D converter, and large size memory disk, a compressive full waveform LIDAR system, which uses a temporally modulated laser instead of a pulsed laser, is studied in this paper. Full waveform data from NEON (National Ecological Observatory Network) are used. Random binary patterns are used to modulate the source. To achieve 0.15 m ranging resolution, a 100 MSPS A/D converter is assumed to make measurements. SPIRAL algorithm with canonical basis is employed when Poisson noise is considered in the low illuminated condition.