Cooling systems and hybrid A/C systems using an electromagnetic radiation-absorbing complex

DOEpatents

Halas, Nancy J.; Nordlander, Peter; Neumann, Oara

2015-05-19

A method for powering a cooling unit. The method including applying electromagnetic (EM) radiation to a complex, where the complex absorbs the EM radiation to generate heat, transforming, using the heat generated by the complex, a fluid to vapor, and sending the vapor from the vessel to a turbine coupled to a generator by a shaft, where the vapor causes the turbine to rotate, which turns the shaft and causes the generator to generate the electric power, wherein the electric powers supplements the power needed to power the cooling unit

The economics of solar powered absorption cooling

NASA Technical Reports Server (NTRS)

Bartlett, J. C.

1978-01-01

Analytic procedure evaluates cost of combining absorption-cycle chiller with solar-energy system in residential or commercial application. Procedure assumes that solar-energy system already exists to heat building and that cooling system must be added. Decision is whether to cool building with conventional vapor-compression-cycle chiller or to use solar-energy system to provide heat input to absorption chiller.

Numerical Hydraulic Study on Seawater Cooling System of Combined Cycle Power Plant

NASA Astrophysics Data System (ADS)

Kim, J. Y.; Park, S. M.; Kim, J. H.; Kim, S. W.

2010-06-01

As the rated flow and pressure increase in pumping facilities, a proper design against surges and severe cavitations in the pipeline system is required. Pressure surge due to start-up, shut-down process and operation failure causes the water hammer in upstream of the closing valve and the cavitational hammer in downstream of the valve. Typical cause of water hammer is the urgent closure of valves by breakdown of power supply and unexpected failure of pumps. The abrupt changes in the flow rate of the liquid results in high pressure surges in upstream of the valves, thus kinetic energy is transformed into potential energy which leads to the sudden increase of the pressure that is called as water hammer. Also, by the inertia, the liquid continues to flow downstream of the valve with initial speed. Accordingly, the pressure decreases and an expanding vapor bubble known as column separation are formed near the valve. In this research, the hydraulic study on the closed cooling water heat exchanger line, which is the one part of the power plant, is introduced. The whole power plant consists of 1,200 MW combined power plant and 220,000 m3/day desalination facility. Cooling water for the plant is supplied by sea water circulating system with a capacity of 29 m3/s. The primary focus is to verify the steady state hydraulic capacity of the system. The secondary is to quantify transient issues and solutions in the system. The circuit was modeled using a commercial software. The stable piping network was designed through the hydraulic studies using the simulation for the various scenarios.

Power electronics cooling apparatus

DOEpatents

Sanger, Philip Albert; Lindberg, Frank A.; Garcen, Walter

2000-01-01

A semiconductor cooling arrangement wherein a semiconductor is affixed to a thermally and electrically conducting carrier such as by brazing. The coefficient of thermal expansion of the semiconductor and carrier are closely matched to one another so that during operation they will not be overstressed mechanically due to thermal cycling. Electrical connection is made to the semiconductor and carrier, and a porous metal heat exchanger is thermally connected to the carrier. The heat exchanger is positioned within an electrically insulating cooling assembly having cooling oil flowing therethrough. The arrangement is particularly well adapted for the cooling of high power switching elements in a power bridge.

Vapor Jet Ejector Used to Generate Free Waste Heat Driven Cooling in Military Environmental Cooling Units

DTIC Science & Technology

2012-07-01

vap erant vapor is or by a J-tub essure side of using similar pressure incre ump in order o the diesel-e per heat excha recovered at to the exhaus...top of the a tering the com at exchanger. g of the conve id flow. A nit essure pulsati tor where the ed in the cool erature level. ger where wa

User's manual for the BNW-I optimization code for dry-cooled power plants. [AMCIRC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braun, D.J.; Daniel, D.J.; De Mier, W.V.

1977-01-01

This appendix provides a listing, called Program AMCIRC, of the BNW-1 optimization code for determining, for a particular size power plant, the optimum dry cooling tower design using ammonia flow in the heat exchanger tubes. The optimum design is determined by repeating the design of the cooling system over a range of design conditions in order to find the cooling system with the smallest incremental cost. This is accomplished by varying five parameters of the plant and cooling system over ranges of values. These parameters are varied systematically according to techniques that perform pattern and gradient searches. The dry coolingmore » system optimized by program AMCIRC is composed of a condenser/reboiler (condensation of steam and boiling of ammonia), piping system (transports ammonia vapor out and ammonia liquid from the dry cooling towers), and circular tower system (vertical one-pass heat exchangers situated in circular configurations with cocurrent ammonia flow in the tubes of the heat exchanger). (LCL)« less

Computation of infrared cooling rates in the water vapor bands

NASA Technical Reports Server (NTRS)

Chou, M. D.; Arking, A.

1978-01-01

A fast but accurate method for calculating the infrared radiative terms due to water vapor has been developed. It makes use of the far wing approximation to scale transmission along an inhomogeneous path to an equivalent homogeneous path. Rather than using standard conditions for scaling, the reference temperatures and pressures are chosen in this study to correspond to the regions where cooling is most significant. This greatly increased the accuracy of the new method. Compared to line by line calculations, the new method has errors up to 4% of the maximum cooling rate, while a commonly used method based upon the Goody band model (Rodgers and Walshaw, 1966) introduces errors up to 11%. The effect of temperature dependence of transmittance has also been evaluated; the cooling rate errors range up to 11% when the temperature dependence is ignored. In addition to being more accurate, the new method is much faster than those based upon the Goody band model.

Direct cooled power electronics substrate

DOEpatents

Wiles, Randy H [Powell, TN; Wereszczak, Andrew A [Oak Ridge, TN; Ayers, Curtis W [Kingston, TN; Lowe, Kirk T [Knoxville, TN

2010-09-14

The disclosure describes directly cooling a three-dimensional, direct metallization (DM) layer in a power electronics device. To enable sufficient cooling, coolant flow channels are formed within the ceramic substrate. The direct metallization layer (typically copper) may be bonded to the ceramic substrate, and semiconductor chips (such as IGBT and diodes) may be soldered or sintered onto the direct metallization layer to form a power electronics module. Multiple modules may be attached to cooling headers that provide in-flow and out-flow of coolant through the channels in the ceramic substrate. The modules and cooling header assembly are preferably sized to fit inside the core of a toroidal shaped capacitor.

Small high cooling power space cooler

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, T. V.; Raab, J.; Durand, D.

The small High Efficiency pulse tube Cooler (HEC) cooler, that has been produced and flown on a number of space infrared instruments, was originally designed to provide cooling of 10 W @ 95 K. It achieved its goal with >50% margin when limited by the 180 W output ac power of its flight electronics. It has also been produced in 2 stage configurations, typically for simultaneously cooling of focal planes to temperatures as low as 35 K and optics at higher temperatures. The need for even higher cooling power in such a low mass cryocooler is motivated by the adventmore » of large focal plane arrays. With the current availability at NGAS of much larger power cryocooler flight electronics, reliable long term operation in space with much larger cooling powers is now possible with the flight proven 4 kg HEC mechanical cooler. Even though the single stage cooler design can be re-qualified for those larger input powers without design change, we redesigned both the linear and coaxial version passive pulse tube cold heads to re-optimize them for high power cooling at temperatures above 130 K while rejecting heat to 300 K. Small changes to the regenerator packing, the re-optimization of the tuned inertance and no change to the compressor resulted in the increased performance at 150 K. The cooler operating at 290 W input power achieves 35 W@ 150 K corresponding to a specific cooling power at 150 K of 8.25 W/W and a very high specific power of 72.5 W/Kg. At these powers the cooler still maintains large stroke, thermal and current margins. In this paper we will present the measured data and the changes to this flight proven cooler that were made to achieve this increased performance.« less

Site dependent factors affecting the economic feasibility of solar powered absorption cooling

NASA Technical Reports Server (NTRS)

Bartlett, J. C.

1978-01-01

A procedure was developed to evaluate the cost effectiveness of combining an absorption cycle chiller with a solar energy system. A basic assumption of the procedure is that a solar energy system exists for meeting the heating load of the building, and that the building must be cooled. The decision to be made is to either cool the building with a conventional vapor compression cycle chiller or to use the existing solar energy system to provide a heat input to the absorption chiller. Two methods of meeting the cooling load not supplied by solar energy were considered. In the first method, heat is supplied to the absorption chiller by a boiler using fossil fuel. In the second method, the load not met by solar energy is net by a conventional vapor compression chiller. In addition, the procedure can consider waste heat as another form of auxiliary energy. Commercial applications of solar cooling with an absorption chiller were found to be more cost effective than the residential applications. In general, it was found that the larger the chiller, the more economically feasible it would be. Also, it was found that a conventional vapor compression chiller is a viable alternative for the auxiliary cooling source, especially for the larger chillers. The results of the analysis gives a relative rating of the sites considered as to their economic feasibility of solar cooling.

NUCLEAR POWER PLANT

DOEpatents

Carter, J.C.; Armstrong, R.H.; Janicke, M.J.

1963-05-14

A nuclear power plant for use in an airless environment or other environment in which cooling is difficult is described. The power plant includes a boiling mercury reactor, a mercury--vapor turbine in direct cycle therewith, and a radiator for condensing mercury vapor. (AEC)

Physical Vapor Transport of Lead Telluride

NASA Technical Reports Server (NTRS)

Palosz, W.

1997-01-01

Mass transport properties of physical vapor transport of PbTe are investigated. Thermochemical analysis of the system and its implications for the growth conditions are discussed. The effect of the material preparation and pre-processing on the stoichiometry and residual gas pressure and composition, and on related mass flux is shown. A procedure leading to high mass transport rates is presented.

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.

Injected Water Augments Cooling In Turboshaft Engine

NASA Technical Reports Server (NTRS)

Biesiadny, Thomas J.; Berger, Brett; Klann, Gary A.; Clark, David A.

1989-01-01

Report describes experiments in which water injected into compressor-bleed cooling air of aircraft turboshaft engine. Injection of water previously suggested as way to provide additional cooling needed to sustain operation at power levels higher than usual. Involves turbine-inlet temperatures high enough to shorten lives of first-stage high-pressure turbine blades. Latent heat of vaporization of injected water serves as additional heat sink to maintain blades at design operating temperatures during high-power operation.

Heat pipe cooled power magnetics

NASA Technical Reports Server (NTRS)

Chester, M. S.

1979-01-01

A high frequency, high power, low specific weight (0.57 kg/kW) transformer developed for space use was redesigned with heat pipe cooling allowing both a reduction in weight and a lower internal temperature rise. The specific weight of the heat pipe cooled transformer was reduced to 0.4 kg/kW and the highest winding temperature rise was reduced from 40 C to 20 C in spite of 10 watts additional loss. The design loss/weight tradeoff was 18 W/kg. Additionally, allowing the same 40 C winding temperature rise as in the original design, the KVA rating is increased to 4.2 KVA, demonstrating a specific weight of 0.28 kg/kW with the internal loss increased by 50W. This space environment tested heat pipe cooled design performed as well electrically as the original conventional design, thus demonstrating the advantages of heat pipes integrated into a high power, high voltage magnetic. Another heat pipe cooled magnetic, a 3.7 kW, 20A input filter inductor was designed, developed, built, tested, and described. The heat pipe cooled magnetics are designed to be Earth operated in any orientation.

Multiple lead seal assembly for a liquid-metal-cooled fast-breeder nuclear reactor

DOEpatents

Hutter, Ernest; Pardini, John A.

1977-03-15

A reusable multiple lead seal assembly provides leak-free passage of stainless-steel-clad instrument leads through the cover on the primary tank of a liquid-metal-cooled fast-breeder nuclear reactor. The seal isolates radioactive argon cover gas and sodium vapor within the primary tank from the exterior atmosphere and permits reuse of the assembly and the stainless-steel-clad instrument leads. Leads are placed in flutes in a seal body, and a seal shell is then placed around the seal body. Circumferential channels in the body and inner surface of the shell are contiguous and together form a conduit which intersects each of the flutes, placing them in communication with a port through the wall of the seal shell. Liquid silicone rubber sealant is injected into the flutes through the port and conduit; the sealant fills the space in the flutes not occupied by the leads themselves and dries to a rubbery hardness. A nut, threaded onto a portion of the seal body not covered by the seal shell, jacks the body out of the shell and shears the sealant without damage to the body, shell, or leads. The leads may then be removed from the body. The sheared sealant is cleaned from the body, leads, and shell and the assembly may then be reused with the same or different leads.

Nonlinear dynamics of confined thin liquid-vapor bilayer systems with phase change

NASA Astrophysics Data System (ADS)

Kanatani, Kentaro; Oron, Alexander

2011-03-01

We numerically investigate the nonlinear evolution of the interface of a thin liquid-vapor bilayer system confined by rigid horizontal walls from both below and above. The lateral variation of the vapor pressure arising from phase change is taken into account in the present analysis. When the liquid (vapor) is heated (cooled) and gravity acts toward the liquid, the deflection of the interface monotonically grows, leading to a rupture of the vapor layer, whereas nonruptured stationary states are found when the liquid (vapor) is cooled (heated) and gravity acts toward the vapor. In the latter case, vapor-flow-driven convective cells are found in the liquid phase in the stationary state. The average vapor pressure and interface temperature deviate from their equilibrium values once the interface departs from the flat equilibrium state. Thermocapillarity does not have a significant effect near the thermodynamic equilibrium, but becomes important if the system significantly deviates from it.

Low-power lead-cooled fast reactor loaded with MOX-fuel

NASA Astrophysics Data System (ADS)

Sitdikov, E. R.; Terekhova, A. M.

2017-01-01

Fast reactor for the purpose of implementation of research, education of undergraduate and doctoral students in handling innovative fast reactors and training specialists for atomic research centers and nuclear power plants (BRUTs) was considered. Hard neutron spectrum achieved in the fast reactor with compact core and lead coolant. Possibility of prompt neutron runaway of the reactor is excluded due to the low reactivity margin which is less than the effective fraction of delayed neutrons. The possibility of using MOX fuel in the BRUTs reactor was examined. The effect of Keff growth connected with replacement of natural lead coolant to 208Pb coolant was evaluated. The calculations and reactor core model were performed using the Serpent Monte Carlo code.

D0 Solenoid Upgrade Project: D0 Solenoid Current Leads

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rucinski, R.; /Fermilab

This engineering note documents information gathered and design decisions made regarding the vapor cooled current leads for the D-Zero Solenoid. The decision was made during design group meetings that the D-Zero Solenoid, rated at 4825 amps, should use vapor cooled current leads rated at 6000 amps. CDF uses 6000 amp leads from American Magnetics Inc. (AMI) and has two spares in their storage lockers. Because of the spares situation and AMI's reputation, AMI would be the natural choice of vendor. The manufacturer's listed helium consumption is 19.2 liters/hr. From experience with these types of leads, more stable operation is acheivedmore » at an increased gas flow. See attached E-Mail message from RLS. We have decided to list the design flow rate at 28.8 liquid liters/hr in the design report. This corresponds to COFs operating point. A question was raised regarding how long the current leads could last at full current should the vapor cooling flow was stopped. This issue was discussed with Scott Smith from AMI. We do not feel that there is a problem for this failure scenario.« less

Cooling Concepts for High Power Density Magnetic Devices

NASA Astrophysics Data System (ADS)

Biela, Juergen; Kolar, Johann W.

In the area or power electronics there is a general trend to higher power densities. In order to increase the power density the systems must be designed optimally concerning topology, semiconductor selection, etc. and the volume of the components must be decreased. The decreasing volume comes along with a reduced surface for cooling. Consequently, new cooling methods are required. In the paper an indirect air cooling system for magnetic devices which combines the transformer with a heat sink and a heat transfer component is presented. Moreover, an analytic approach for calculating the temperature distribution is derived and validated by measurements. Based on these equations a transformer with an indirect air cooling system is designed for a 10kW telecom power supply.

Performance Analysis of XCPC Powered Solar Cooling Demonstration Project

NASA Astrophysics Data System (ADS)

Widyolar, Bennett K.

A solar thermal cooling system using novel non-tracking External Compound Parabolic Concentrators (XCPC) has been built at the University of California, Merced and operated for two cooling seasons. Its performance in providing power for space cooling has been analyzed. This solar cooling system is comprised of 53.3 m2 of XCPC trough collectors which are used to power a 23 kW double effect (LiBr) absorption chiller. This is the first system that combines both XCPC and absorption chilling technologies. Performance of the system was measured in both sunny and cloudy conditions, with both clean and dirty collectors. It was found that these collectors are well suited at providing thermal power to drive absorption cooling systems and that both the coinciding of available thermal power with cooling demand and the simplicity of the XCPC collectors compared to other solar thermal collectors makes them a highly attractive candidate for cooling projects.

Shock-induced vaporization of anhydrite and global cooling from the K/T impact

NASA Astrophysics Data System (ADS)

Gupta, Satish C.; Ahrens, Thomas J.; Yang, Wenbo

2001-06-01

Discovery of abundant anhydrite (CaSO 4) and gypsum (CaSO 4·2H 2O) in the otherwise carbonate sediment comprising the upper 3 km thick layer of the target rock at the K/T impact site has prompted research on these minerals. Evaluation of the severity of the proposed extinction mechanism involving injection of impact-generated SO 2 and SO 3 into the stratosphere entails determination of criteria for shock-induced vaporization of these minerals. In the present work we present new data on the vaporization criteria of anhydrite. These are based on the reanalysis of the shock wave experiments of Yang and Ahrens [Earth Planet. Sci. Lett. 156 (1998) 125-140], conducted on material with 30% porosity, in which the shock- (fully or partially) vaporized sample interacts with an overlying LiF window. The velocity histories, monitored using a velocity interferometer, are compared with numerical simulations employing an improved equation of state for porous anhydrite and its vaporization products. We also employ the 'entropy criterion' for vaporization of material under shock compression. The values of the entropies of incipient and complete vaporization for anhydrite are determined to be 1.65±0.12 and 3.17±0.12 kJ (kg K) -1, respectively, and the corresponding pressures for incipient and the complete vaporization along the Hugoniot for the solid material are 32.5±2.5 and 122±13 GPa, respectively as compared with 81±7 and 155±13 GPa previously reported by Yang and Ahrens. Along with these criteria, the use of the recent estimate of diameter (100 km) for the Chicxulub transient crater [O'Keefe and Ahrens, J. Geophys. Res. 104 (E11) (1999) 27091-27104; Morgan et al., Nature 390 (1997) 472-476] that is smaller than previously assumed, along with Ivanov et al.'s [Geol. Soc. Am. Spec. Pap. 307 (1996) 125-142] 2-D hydrodynamic simulation to determine the shock attenuation and Pope et al.'s [J. Geophys. Res., 102 (E9) (1997) 21645-21664] radiative transfer model, yields the

Heat pipe cooling for scramjet engines

NASA Technical Reports Server (NTRS)

Silverstein, Calvin C.

1986-01-01

Liquid metal heat pipe cooling systems have been investigated for the combustor liner and engine inlet leading edges of scramjet engines for a missile application. The combustor liner is cooled by a lithium-TZM molybdenum annular heat pipe, which incorporates a separate lithium reservoir. Heat is initially absorbed by the sensible thermal capacity of the heat pipe and liner, and subsequently by the vaporization and discharge of lithium to the atmosphere. The combustor liner temperature is maintained at 3400 F or less during steady-state cruise. The engine inlet leading edge is fabricated as a sodium-superalloy heat pipe. Cooling is accomplished by radiation of heat from the aft surface of the leading edge to the atmosphere. The leading edge temperature is limited to 1700 F or less. It is concluded that heat pipe cooling is a viable method for limiting scramjet combustor liner and engine inlet temperatures to levels at which structural integrity is greatly enhanced.

Vapor-barrier Vacuum Isolation System

NASA Technical Reports Server (NTRS)

Weinstein, Leonard M. (Inventor); Taminger, Karen M. (Inventor)

2014-01-01

A system includes a collimated beam source within a vacuum chamber, a condensable barrier gas, cooling material, a pump, and isolation chambers cooled by the cooling material to condense the barrier gas. Pressure levels of each isolation chamber are substantially greater than in the vacuum chamber. Coaxially-aligned orifices connect a working chamber, the isolation chambers, and the vacuum chamber. The pump evacuates uncondensed barrier gas. The barrier gas blocks entry of atmospheric vapor from the working chamber into the isolation chambers, and undergoes supersonic flow expansion upon entering each isolation chamber. A method includes connecting the isolation chambers to the vacuum chamber, directing vapor to a boundary with the working chamber, and supersonically expanding the vapor as it enters the isolation chambers via the orifices. The vapor condenses in each isolation chamber using the cooling material, and uncondensed vapor is pumped out of the isolation chambers via the pump.

Convective Array Cooling for a Solar Powered Aircraft

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.; Dolce, James (Technical Monitor)

2003-01-01

A general characteristic of photovoltaics is that they increase in efficiency as their operating temperature decreases. Based on this principal, the ability to increase a solar aircraft's performance by cooling the solar cells was examined. The solar cells were cooled by channeling some air underneath the cells and providing a convective cooling path to the back side of the array. A full energy balance and flow analysis of the air within the cooling passage was performed. The analysis was first performed on a preliminary level to estimate the benefits of the cooling passage. This analysis established a clear benefit to the cooling passage. Based on these results a more detailed analysis was performed. From this cell temperatures were calculated and array output power throughout a day period were determined with and without the cooling passage. The results showed that if the flow through the cooling passage remained laminar then the benefit in increased output power more than offset the drag induced by the cooling passage.

Heat pipe cooling of power processing magnetics

NASA Technical Reports Server (NTRS)

Hansen, I. G.; Chester, M.

1979-01-01

The constant demand for increased power and reduced mass has raised the internal temperature of conventionally cooled power magnetics toward the upper limit of acceptability. The conflicting demands of electrical isolation, mechanical integrity, and thermal conductivity preclude significant further advancements using conventional approaches. However, the size and mass of multikilowatt power processing systems may be further reduced by the incorporation of heat pipe cooling directly into the power magnetics. Additionally, by maintaining lower more constant temperatures, the life and reliability of the magnetic devices will be improved. A heat pipe cooled transformer and input filter have been developed for the 2.4 kW beam supply of a 30-cm ion thruster system. This development yielded a mass reduction of 40% (1.76 kg) and lower mean winding temperature (20 C lower). While these improvements are significant, preliminary designs predict even greater benefits to be realized at higher power. This paper presents the design details along with the results of thermal vacuum operation and the component performance in a 3 kW breadboard power processor.

VAPOR SHIELD FOR INDUCTION FURNACE

DOEpatents

Reese, S.L.; Samoriga, S.A.

1958-03-11

This patent relates to a water-cooled vapor shield for an inductlon furnace that will condense metallic vapors arising from the crucible and thus prevent their condensation on or near the induction coils, thereby eliminating possible corrosion or shorting out of the coils. This is accomplished by placing, about the top, of the crucible a disk, apron, and cooling jacket that separates the area of the coils from the interior of the cruclbIe and provides a cooled surface upon whlch the vapors may condense.

Vapor Compression and Thermoelectric Heat Pumps for a Cascade Distillation Subsystem: Design and Experiment

NASA Technical Reports Server (NTRS)

Erickson, Lisa R.; Ungar, Eugene K.

2012-01-01

Humans on a spacecraft require significant amounts of water for drinking, food, hydration, and hygiene. Maximizing the reuse of wastewater while minimizing the use of consumables is critical for long duration space exploration. One of the more promising consumable-free methods of reclaiming wastewater is the distillation/condensation process used in the Cascade Distillation Subsystem (CDS). The CDS heats wastewater to the point of vaporization then condenses and cools the resulting water vapor. The CDS wastewater flow requires heating for evaporation and the product water flow requires cooling for condensation. Performing the heating and cooling processes separately would require two separate units, each of which would demand large amounts of electrical power. Mass, volume, and power efficiencies can be obtained by heating the wastewater and cooling the condensate in a single heat pump unit. The present work describes and compares two competing heat pump methodologies that meet the needs of the CDS: 1) a series of mini compressor vapor compression cycles and 2) a thermoelectric heat exchanger. In the paper, the CDS system level requirements are outlined, the designs of the two heat pumps are described in detail, and the results of heat pump analysis and performance tests are provided. The mass, volume, and power requirement for each heat pump option is compared and the advantages and disadvantages of each system are listed.

Vapor Compression and Thermoelectric Heat Pump Heat Exchangers for a Condensate Distillation System: Design and Experiment

NASA Technical Reports Server (NTRS)

Erickson, Lisa R.; Ungar, Eugene K.

2013-01-01

Maximizing the reuse of wastewater while minimizing the use of consumables is critical in long duration space exploration. One of the more promising methods of reclaiming urine is the distillation/condensation process used in the cascade distillation system (CDS). This system accepts a mixture of urine and toxic stabilizing agents, heats it to vaporize the water and condenses and cools the resulting water vapor. The CDS wastewater flow requires heating and its condensate flow requires cooling. Performing the heating and cooling processes separately requires two separate units, each of which would require large amounts of electrical power. By heating the wastewater and cooling the condensate in a single heat pump unit, mass, volume, and power efficiencies can be obtained. The present work describes and compares two competing heat pump methodologies that meet the needs of the CDS: 1) a series of mini compressor vapor compression cycles and 2) a thermoelectric heat exchanger. In the paper, the system level requirements are outlined, the designs of the two heat pumps are described in detail, and the results of heat pump performance tests are provided. A summary is provided of the heat pump mass, volume and power trades and a selection recommendation is made.

Water cooled steam jet

DOEpatents

Wagner, Jr., Edward P.

1999-01-01

A water cooled steam jet for transferring fluid and preventing vapor lock, or vaporization of the fluid being transferred, has a venturi nozzle and a cooling jacket. The venturi nozzle produces a high velocity flow which creates a vacuum to draw fluid from a source of fluid. The venturi nozzle has a converging section connected to a source of steam, a diffuser section attached to an outlet and a throat portion disposed therebetween. The cooling jacket surrounds the venturi nozzle and a suction tube through which the fluid is being drawn into the venturi nozzle. Coolant flows through the cooling jacket. The cooling jacket dissipates heat generated by the venturi nozzle to prevent vapor lock.

Water cooled steam jet

DOEpatents

Wagner, E.P. Jr.

1999-01-12

A water cooled steam jet for transferring fluid and preventing vapor lock, or vaporization of the fluid being transferred, has a venturi nozzle and a cooling jacket. The venturi nozzle produces a high velocity flow which creates a vacuum to draw fluid from a source of fluid. The venturi nozzle has a converging section connected to a source of steam, a diffuser section attached to an outlet and a throat portion disposed there between. The cooling jacket surrounds the venturi nozzle and a suction tube through which the fluid is being drawn into the venturi nozzle. Coolant flows through the cooling jacket. The cooling jacket dissipates heat generated by the venturi nozzle to prevent vapor lock. 2 figs.

Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sutter-Fella, Carolin M.; Li, Yanbo; Cefarin, Nicola

Organo-lead halide perovskites have recently attracted great interest for potential applications in thin-film photovoltaics and optoelectronics. Herein, we present a protocol for the fabrication of this material via the low-pressure vapor assisted solution process (LP-VASP) method, which yields ~19% power conversion efficiency in planar heterojunction perovskite solar cells. First, we report the synthesis of methylammonium iodide (CH 3NH 3I) and methylammonium bromide (CH 3NH 3Br) from methylamine and the corresponding halide acid (HI or HBr). Then, we describe the fabrication of pinhole-free, continuous methylammonium-lead halide perovskite (CH 3NH 3PbX 3 with X = I, Br, Cl and their mixture) filmsmore » with the LP-VASP. This process is based on two steps: i) spin-coating of a homogenous layer of lead halide precursor onto a substrate, and ii) conversion of this layer to CH 3NH 3PbI 3-xBr x by exposing the substrate to vapors of a mixture of CH 3NH 3I and CH 3NH 3Br at reduced pressure and 120 °C. Through slow diffusion of the methylammonium halide vapor into the lead halide precursor, we achieve slow and controlled growth of a continuous, pinhole-free perovskite film. The LP-VASP allows synthetic access to the full halide composition space in CH 3NH 3PbI 3-xBr x with 0 ≤ x ≤ 3. Depending on the composition of the vapor phase, the bandgap can be tuned between 1.6 eV ≤ E g ≤ 2.3 eV. In addition, by varying the composition of the halide precursor and of the vapor phase, we can also obtain CH 3NH 3PbI 3-xCl x. Films obtained from the LP-VASP are reproducible, phase pure as confirmed by X-ray diffraction measurements, and show high photoluminescence quantum yield. The process does not require the use of a glovebox.« less

Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films

DOE PAGES

Sutter-Fella, Carolin M.; Li, Yanbo; Cefarin, Nicola; ...

2017-09-08

Organo-lead halide perovskites have recently attracted great interest for potential applications in thin-film photovoltaics and optoelectronics. Herein, we present a protocol for the fabrication of this material via the low-pressure vapor assisted solution process (LP-VASP) method, which yields ~19% power conversion efficiency in planar heterojunction perovskite solar cells. First, we report the synthesis of methylammonium iodide (CH 3NH 3I) and methylammonium bromide (CH 3NH 3Br) from methylamine and the corresponding halide acid (HI or HBr). Then, we describe the fabrication of pinhole-free, continuous methylammonium-lead halide perovskite (CH 3NH 3PbX 3 with X = I, Br, Cl and their mixture) filmsmore » with the LP-VASP. This process is based on two steps: i) spin-coating of a homogenous layer of lead halide precursor onto a substrate, and ii) conversion of this layer to CH 3NH 3PbI 3-xBr x by exposing the substrate to vapors of a mixture of CH 3NH 3I and CH 3NH 3Br at reduced pressure and 120 °C. Through slow diffusion of the methylammonium halide vapor into the lead halide precursor, we achieve slow and controlled growth of a continuous, pinhole-free perovskite film. The LP-VASP allows synthetic access to the full halide composition space in CH 3NH 3PbI 3-xBr x with 0 ≤ x ≤ 3. Depending on the composition of the vapor phase, the bandgap can be tuned between 1.6 eV ≤ E g ≤ 2.3 eV. In addition, by varying the composition of the halide precursor and of the vapor phase, we can also obtain CH 3NH 3PbI 3-xCl x. Films obtained from the LP-VASP are reproducible, phase pure as confirmed by X-ray diffraction measurements, and show high photoluminescence quantum yield. The process does not require the use of a glovebox.« less

Preliminary design package for solar heating and cooling systems

NASA Technical Reports Server (NTRS)

1978-01-01

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

Interim status report on lead-cooled fast reactor (LFR) research and development.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tzanos, C. P.; Sienicki, J. J.; Moisseytsev, A.

2008-03-31

This report discusses the status of Lead-Cooled Fast Reactor (LFR) research and development carried out during the first half of FY 2008 under the U.S. Department of Energy Generation IV Nuclear Energy Systems Initiative. Lead-Cooled Fast Reactor research and development has recently been transferred from Generation IV to the Reactor Campaign of the Global Nuclear Energy Partnership (GNEP). Another status report shall be issued at the end of FY 2008 covering all of the LFR activities carried out in FY 2008 for both Generation IV and GNEP. The focus of research and development in FY 2008 is an initial investigationmore » of a concept for a LFR Advanced Recycling Reactor (ARR) Technology Pilot Plant (TPP)/demonstration test reactor (demo) incorporating features and operating conditions of the European Lead-cooled SYstem (ELSY) {approx} 600 MWe lead (Pb)-cooled LFR preconceptual design for the transmutation of waste and central station power generation, and which would enable irradiation testing of advanced fuels and structural materials. Initial scoping core concept development analyses have been carried out for a 100 MWt core composed of sixteen open-lattice 20 by 20 fuel assemblies largely similar to those of the ELSY preconceptual fuel assembly design incorporating fuel pins with mixed oxide (MOX) fuel, central control rods in each fuel assembly, and cooled with Pb coolant. For a cycle length of three years, the core is calculated to have a conversion ratio of 0.79, an average discharge burnup of 108 MWd/kg of heavy metal, and a burnup reactivity swing of about 13 dollars. With a control rod in each fuel assembly, the reactivity worth of an individual rod would need to be significantly greater than one dollar which is undesirable for postulated rod withdrawal reactivity insertion events. A peak neutron fast flux of 2.0 x 10{sup 15} (n/cm{sup 2}-s) is calculated. For comparison, the 400 MWt Fast Flux Test Facility (FFTF) achieved a peak neutron fast flux of 7.2 x

A Novel Low-Power, High-Performance, Zero-Maintenance Closed-Path Trace Gas Eddy Covariance System with No Water Vapor Dilution or Spectroscopic Corrections

NASA Astrophysics Data System (ADS)

Sargent, S.; Somers, J. M.

2015-12-01

Trace-gas eddy covariance flux measurement can be made with open-path or closed-path analyzers. Traditional closed-path trace-gas analyzers use multipass absorption cells that behave as mixing volumes, requiring high sample flow rates to achieve useful frequency response. The high sample flow rate and the need to keep the multipass cell extremely clean dictates the use of a fine-pore filter that may clog quickly. A large-capacity filter cannot be used because it would degrade the EC system frequency response. The high flow rate also requires a powerful vacuum pump, which will typically consume on the order of 1000 W. The analyzer must measure water vapor for spectroscopic and dilution corrections. Open-path analyzers are available for methane, but not for nitrous oxide. The currently available methane analyzers have low power consumption, but are very large. Their large size degrades frequency response and disturbs the air flow near the sonic anemometer. They require significant maintenance to keep the exposed multipass optical surfaces clean. Water vapor measurements for dilution and spectroscopic corrections require a separate water vapor analyzer. A new closed-path eddy covariance system for measuring nitrous oxide or methane fluxes provides an elegant solution. The analyzer (TGA200A, Campbell Scientific, Inc.) uses a thermoelectrically-cooled interband cascade laser. Its small sample-cell volume and unique sample-cell configuration (200 ml, 1.5 m single pass) provide excellent frequency response with a low-power scroll pump (240 W). A new single-tube Nafion® dryer removes most of the water vapor, and attenuates fluctuations in the residual water vapor. Finally, a vortex intake assembly eliminates the need for an intake filter without adding volume that would degrade system frequency response. Laboratory testing shows the system attenuates the water vapor dilution term by more than 99% and achieves a half-power band width of 3.5 Hz.

Solar-powered cooling system

DOEpatents

Farmer, Joseph C

2013-12-24

A solar-powered adsorption-desorption refrigeration and air conditioning system uses nanostructural materials made of high specific surface area adsorption aerogel as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material. A circulation system circulates refrigerant from the nanostructural material to a cooling unit.

Heat-Pipe-Cooled Leading Edges for Hypersonic Vehicles

NASA Technical Reports Server (NTRS)

Glass, David E.

2006-01-01

Heat pipes can be used to effectively cool wing leading edges of hypersonic vehicles. . Heat-pipe leading edge development. Design validation heat pipe testing confirmed design. Three heat pipes embedded and tested in C/C. Single J-tube heat pipe fabricated and testing initiated. HPCLE work is currently underway at several locations.

Surface Power Radiative Cooling Tests

NASA Astrophysics Data System (ADS)

Vaughn, Jason; Schneider, Todd

2006-01-01

Terrestrial nuclear power plants typically maintain their temperature through convective cooling, such as water and forced air. However, the space environment is a vacuum environment, typically 10-8 Torr pressure, therefore in proposed missions to the lunar surface, power plants would have to rely on radiative cooling to remove waste heat. Also, the Martian surface has a very tenuous atmosphere (e.g. ~5 Torr CO2), therefore, the main heat transfer method on the Martian surface is also radiative. Because of the lack of atmosphere on the Moon and the tenuous atmosphere on Mars, surface power systems on both the Lunar and Martian surface must rely heavily on radiative heat transfer. Because of the large temperature swings on both the lunar and the Martian surfaces, trying to radiate heat is inefficient. In order to increase power system efficiency, an effort is underway to test various combinations of materials with high emissivities to demonstrate their ability to survive these degrading atmospheres to maintain a constant radiator temperature improving surface power plant efficiency. An important part of this effort is the development of a unique capability that would allow the determination of a materials emissivity at high temperatures. A description of the test capability as well as initial data is presented.

Slow hot carrier cooling in cesium lead iodide perovskites

NASA Astrophysics Data System (ADS)

Shen, Qing; Ripolles, Teresa S.; Even, Jacky; Ogomi, Yuhei; Nishinaka, Koji; Izuishi, Takuya; Nakazawa, Naoki; Zhang, Yaohong; Ding, Chao; Liu, Feng; Toyoda, Taro; Yoshino, Kenji; Minemoto, Takashi; Katayama, Kenji; Hayase, Shuzi

2017-10-01

Lead halide perovskites are attracting a great deal of interest for optoelectronic applications such as solar cells, LEDs, and lasers because of their unique properties. In solar cells, heat dissipation by hot carriers results in a major energy loss channel responsible for the Shockley-Queisser efficiency limit. Hot carrier solar cells offer the possibility to overcome this limit and achieve energy conversion efficiency as high as 66% by extracting hot carriers. Therefore, fundamental studies on hot carrier relaxation dynamics in lead halide perovskites are important. Here, we elucidated the hot carrier cooling dynamics in all-inorganic cesium lead iodide (CsPbI3) perovskite using transient absorption spectroscopy. We observe that the hot carrier cooling rate in CsPbI3 decreases as the fluence of the pump light increases and the cooling is as slow as a few 10 ps when the photoexcited carrier density is 7 × 1018 cm-3, which is attributed to phonon bottleneck for high photoexcited carrier densities. Our findings suggest that CsPbI3 has a potential for hot carrier solar cell applications.

Performance analysis for minimally nonlinear irreversible refrigerators at finite cooling power

NASA Astrophysics Data System (ADS)

Long, Rui; Liu, Zhichun; Liu, Wei

2018-04-01

The coefficient of performance (COP) for general refrigerators at finite cooling power have been systematically researched through the minimally nonlinear irreversible model, and its lower and upper bounds in different operating regions have been proposed. Under the tight coupling conditions, we have calculated the universal COP bounds under the χ figure of merit in different operating regions. When the refrigerator operates in the region with lower external flux, we obtained the general bounds (0 < ε <(√{ 9 + 8εC } - 3) / 2) under the χ figure of merit. We have also calculated the universal bounds for maximum gain in COP under different operating regions to give a further insight into the COP gain with the cooling power away from the maximum one. When the refrigerator operates in the region located between maximum cooling power and maximum COP with lower external flux, the upper bound for COP and the lower bound for relative gain in COP present large values, compared to a relative small loss from the maximum cooling power. If the cooling power is the main objective, it is desirable to operate the refrigerator at a slightly lower cooling power than at the maximum one, where a small loss in the cooling power induces a much larger COP enhancement.

Cooling System Design for PEM Fuel Cell Powered Air Vehicles

DTIC Science & Technology

2010-06-18

Research Laboratory (NRL) has developed a proton exchange membrane fuel cell ( PEMFC ) powered unmanned air vehicle (UAV) called the Ion Tiger. The Ion Tiger...to design a cooling system for the Ion Tiger and investigate cooling approaches that may be suitable for future PEMFC powered air vehicles. The...modifications) to other PEMFC systems utilizing a CHE for cooling. 18-06-2010 Memorandum Report Unmanned Air Vehicle UAV Fuel cell PEM Cooling Radiator January

Design and application of air-conditioning suit based on eddy current cooling principle for distribution network working with power uninterrupted

NASA Astrophysics Data System (ADS)

Xu, Li; Liu, Lanlan; Niu, Jie; Tang, Li; Li, Jinliang; Zhou, Zhanfan; Long, Chenhai; Yang, Qi; Yi, Ziqi; Guo, Hao; Long, Yang; Fu, Yanyi

2017-05-01

As social requirement of power supply reliability keeps rising, distribution network working with power uninterrupted has been widely carried out, while the high - temperature operating environment in summer can easily lead to physical discomfort for the operators, and then lead to safety incidents. Aiming at above problem, air-conditioning suit for distribution network working with power uninterrupted has been putted forward in this paper, and the structure composition and cooling principle of which has been explained, and it has been ultimately put to on-site application. The results showed that, cooling effect of air-conditioning suits was remarkable, and improved the working environment for the operators effectively, which is of great significance to improve Chinese level of working with power uninterrupted, reduce the probability of accidents and enhance the reliability of power supply.

Vaporization of a solid surface in an ambient gas

NASA Astrophysics Data System (ADS)

Benilov, M. S.; Jacobsson, S.; Kaddani, A.; Zahrai, S.

2001-07-01

The net flux of vapour from a solid surface in an ambient gas is analysed with the aim to estimate the effect of vaporization cooling on the energy balance of an arc cathode under conditions typical for a high-power current breaker. If the ratio of the equilibrium vapour pressure pv to the ambient pressure p∞ is smaller than unity, the removal of vapour from the surface is due to diffusion into the bulk of the gas. As a consequence, the net flux of the vapour from the surface is much smaller than the emitted flux. An estimate of the diffusion rate under conditions typical for a high-power current breaker indicates that vaporization cooling plays a minor role in the energy balance of the cathode in this case. If ratio pv/p∞ is above unity, the flow of the vapour from the surface appears and the net flux is comparable to the emitted flux. A simple analytical solution has been obtained for this case, which is in a good agreement with results of the Monte Carlo modelling of preceding authors. If pv/p∞ exceeds approximately 4.5, vaporization occurs as into vacuum and the net flux is about 0.82 of the emitted flux.

Hydroxyl Radical Fluorescence and Quantum Yield Following Lyman-α Photoexcitation of Water Vapor in a Room Temperature Cell and Cooled in a Supersonic Expansion.

PubMed

Young, Justin W; Booth, Ryan S; Vogelhuber, Kristen M; Stearns, Jaime A; Annesley, Christopher J

2018-06-28

Photoexcitation of water by Lyman-α (121.6 nm) induces a dissociation reaction that produces OH(A 2 Σ + ) + H. Despite this reaction being part of numerous studies, a combined understanding of the product and fluorescence yields is still lacking. Here, the rotational and vibrational distributions of OH(A) are determined from dispersed fluorescence following photoexcitation of both room-temperature and jet-cooled water vapor, for the first time in the same experiment. This work compares new data of state-resolved fluorescence with literature molecular branching ratios and brings previous studies into agreement through careful consideration of OH(A) fluorescent and predissociation lifetimes and confirms a fluorescent quantum yield of 8%. Comparison of the room-temperature and jet-cooled OH(A) populations indicate the temperature of H 2 O prior to excitation has subtle effects on the OH(A) population distribution, such as altering the rotational distribution in the ν' = 0 population and affecting the population in the ν' = 1 state. These results indicate jet-cooled water vapor may have a 1% higher fluorescence quantum yield compared to room-temperature water vapor.

Complete indium-free CW 200W passively cooled high power diode laser array using double-side cooling technology

NASA Astrophysics Data System (ADS)

Wang, Jingwei; Zhu, Pengfei; Liu, Hui; Liang, Xuejie; Wu, Dihai; Liu, Yalong; Yu, Dongshan; Zah, Chung-en; Liu, Xingsheng

2017-02-01

High power diode lasers have been widely used in many fields. To meet the requirements of high power and high reliability, passively cooled single bar CS-packaged diode lasers must be robust to withstand thermal fatigue and operate long lifetime. In this work, a novel complete indium-free double-side cooling technology has been applied to package passively cooled high power diode lasers. Thermal behavior of hard solder CS-package diode lasers with different packaging structures was simulated and analyzed. Based on these results, the device structure and packaging process of double-side cooled CS-packaged diode lasers were optimized. A series of CW 200W 940nm high power diode lasers were developed and fabricated using hard solder bonding technology. The performance of the CW 200W 940nm high power diode lasers, such as output power, spectrum, thermal resistance, near field, far field, smile, lifetime, etc., is characterized and analyzed.

Pulsed Film Cooling on a Turbine Blade Leading Edge

DTIC Science & Technology

2009-09-01

LEADING EDGE 1. Introduction Gas turbine engines are based on the Brayton cycle in which atmospheric air is compressed, heated via combustion...generation. Because the working fluid is in an open loop, a cooling process is absent from the Brayton cycle. The ideal Brayton cycle (one in which...Technology, Taylor & Francis, 2000. Harrison, K. and Bogard, D., “CFD Predictions of Film Cooling Adiabatic Effectiveness for Cylindrical Holes Embedded

Modeling of Electron Transpiration Cooling for Leading Edges of Hypersonic Vehicles

NASA Astrophysics Data System (ADS)

Hanquist, Kyle Matthew

approach, ETC is investigated as a viable technology for a wide range of hypersonic operating conditions. This includes altitudes between 30 and 60 km, freestream velocities between 4 and 8 km/s, and leading edge radii between 1 mm and 10 cm. The results presented in this study show that ETC can reduce the leading edge temperature significantly for certain conditions, most notably from 3120 to 1660 K for Mach 26 flight for a sharp leading edge (1 cm). However, at lower velocities, the cooling effect can be diminished by space-charge limits in the plasma sheath. ETC is shown to be most effective at cooling hotter surfaces (e.g. high freestream velocities and sharp leading edges) and the level of ionization in the flowfield can help the emission overcome space-charge limits. The modeling approach is assessed using experiments from the 1960s where thermionic emission was investigated as a mode of power generation for reentry vehicles. The computational results produce a wide range of emitted current due to the uncertainty in the freestream conditions and material properties, but they still agree well with the experiments. Overall, this work indicates that ETC is a viable method of managing the immense heat loads on sharp leading edges during hypersonic flight for certain conditions and motivates future work in the area both computationally and experimentally.

Preliminary neutronics design of china lead-alloy cooled demonstration reactor (CLEAR-III) for nuclear waste transmutation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Z.; Southwest Science and Technology Univ., No.350 Shushanhu Road, Shushan District, Hefei, Anhui, 230031; Chen, Y.

2012-07-01

China Lead-Alloy cooled Demonstration Reactor (CLEAR-III), which is the concept of lead-bismuth cooled accelerator driven sub-critical reactor for nuclear waste transmutation, was proposed and designed by FDS team in China. In this study, preliminary neutronics design studies have primarily focused on three important performance parameters including Transmutation Support Ratio (TSR), effective multiplication factor and blanket thermal power. The constraint parameters, such as power peaking factor and initial TRU loading, were also considered. In the specific design, uranium-free metallic dispersion fuel of (TRU-Zr)-Zr was used as one of the CLEAR-III fuel types and the ratio between MA and Pu was adjustedmore » to maximize transmutation ratio. In addition, three different fuel zones differing in the TRU fraction of the fuel were respectively employed for this subcritical reactor, and the zone sizes and TRU fractions were determined such that the linear powers of these zones were close to each other. The neutronics calculations and analyses were performed by using Multi-Functional 4D Neutronics Simulation System named VisualBUS and nuclear data library HENDL (Hybrid Evaluated Nuclear Data Library). In the preliminary design, the maximum TSRLLMA was {approx}11 and the blanket thermal power was {approx}1000 MW when the effective multiplication factor was 0.98. The results showed that good performance of transmutation could be achieved based on the subcritical reactor loaded with uranium-free fuel. (authors)« less

Small Business Voucher CRADA Report: Natural Gas Powered HVAC System for Commercial and Residential Buildings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Betts, Daniel; Ally, Moonis Raza; Mudiraj, Shyam

Be Power Tech is commercializing BeCool, the first integrated electricity-producing heating, ventilation, and air conditioning (HVAC) system using a non-vapor compression cycle (VCC), packaged rooftop HVAC unit that also produces base-load electricity, heating, ventilation, and air conditioning. BeCool is a distributed energy resource with energy storage that eliminates the tremendous peak electricity demand associated with commonly used electricity-powered vapor compression air conditioning systems.

Cooling Strategies for Vane Leading Edges in a Syngas Environment Including Effects of Deposition and Turbulence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ames, Forrest; Bons, Jeffrey

2014-09-30

The Department of Energy has goals to move land based gas turbine systems to alternate fuels including coal derived synthetic gas and hydrogen. Coal is the most abundant energy resource in the US and in the world and it is economically advantageous to develop power systems which can use coal. Integrated gasification combined cycles are (IGCC) expected to allow the clean use of coal derived fuels while improving the ability to capture and sequester carbon dioxide. These cycles will need to maintain or increase turbine entry temperatures to develop competitive efficiencies. The use of coal derived syngas introduces a rangemore » of potential contaminants into the hot section of the gas turbine including sulfur, iron, calcium, and various alkali metals. Depending on the effectiveness of the gas clean up processes, there exists significant likelihood that the remaining materials will become molten in the combustion process and potentially deposit on downstream turbine surfaces. Past evidence suggests that deposition will be a strong function of increasing temperature. Currently, even with the best gas cleanup processes a small level of particulate matter in the syngas is expected. Consequently, particulate deposition is expected to be an important consideration in the design of turbine components. The leading edge region of first stage vanes most often have higher deposition rates than other areas due to strong fluid acceleration and streamline curvature in the vicinity of the surface. This region remains one of the most difficult areas in a turbine nozzle to cool due to high inlet temperatures and only a small pressure ratio for cooling. The leading edge of a vane often has relatively high heat transfer coefficients and is often cooled using showerhead film cooling arrays. The throat of the first stage nozzle is another area where deposition potentially has a strongly adverse effect on turbine performance as this region meters the turbine inlet flow. Based on

A feasibility study of heat-pipe-cooled leading edges for hypersonic cruise aircraft

NASA Technical Reports Server (NTRS)

Silverstein, C. C.

1971-01-01

A theoretical study of the use of heat pipe structures for cooling the leading edges of hypersonic cruise aircraft was carried out over a Mach number range of 6 to 12. Preliminary design studies showed that a heat pipe cooling structure with a 33-in. chordwise length could maintain the maximum temperature of a 65 deg sweepback wing with a 0.5-in. leading edge radius below 1600 F during cruise at Mach 8. A few relatively minor changes in the steady-state design of the structure were found necessary to insure satisfactory cooling during the climb to cruise speed and altitude. It was concluded that heat pipe cooling is an attractive, feasible technique for limiting leading edge temperatures of hypersonic cruise aircraft.

Binary vapor cycle method of electrical power generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Humiston, G.F.

1982-04-13

A binary vapor cycle method of electrical power generation is disclosed wherein two refrigerant fluids can be used to operate an apparatus for the generation of mechanical power as well as electrical power generation. This method, which is essentially a dual heat pump system, offers an approach to utilizing the advantages of two different refrigerants within a single apparatus. This advantage is particularly advantageous in the ulitization of low specific energy sources, such as two water sources which exist in close proximity to each other, but at different temperatures. Thus, water, which itself is a heat pump fluid, can bemore » used as a means of transmitting heat energy to a second heat pump fluid, or refrigerant, without incurring the disadvantages of water, or water vapors, as a means to produce power, because of its high specific volume and low saturation pressures at low temperatures. Additionally, since the warm water source of energy most commonly available is in the form of reservoirs, such as the ocean waters, and the utilization of barometric legs to bring the warm water into contact with the process, eliminates the use of expensive heat exchangers, which is the case of ocean water, are subject to fouling and loss of efficiency due to clinging microorganisms.« less

Design and optimization of geothermal power generation, heating, and cooling

NASA Astrophysics Data System (ADS)

Kanoglu, Mehmet

Most of the world's geothermal power plants have been built in 1970s and 1980s following 1973 oil crisis. Urgency to generate electricity from alternative energy sources and the fact that geothermal energy was essentially free adversely affected careful designs of plants which would maximize their performance for a given geothermal resource. There are, however, tremendous potentials to improve performance of many existing geothermal power plants by retrofitting, optimizing the operating conditions, re-selecting the most appropriate binary fluid in binary plants, and considering cogeneration such as a district heating and/or cooling system or a system to preheat water entering boilers in industrial facilities. In this dissertation, some representative geothermal resources and existing geothermal power plants in Nevada are investigated to show these potentials. Economic analysis of a typical geothermal resource shows that geothermal heating and cooling may generate up to 3 times as much revenue as power generation alone. A district heating/cooling system is designed for its incorporation into an existing 27 MW air-cooled binary geothermal power plant. The system as designed has the capability to meet the entire heating needs of an industrial park as well as 40% of its cooling needs, generating potential revenues of $14,040,000 per year. A study of the power plant shows that evaporative cooling can increase the power output by up to 29% in summer by decreasing the condenser temperature. The power output of the plant can be increased by 2.8 percent by optimizing the maximum pressure in the cycle. Also, replacing the existing working fluid isobutane by butane, R-114, isopentane, and pentane can increase the power output by up to 2.5 percent. Investigation of some well-known geothermal power generation technologies as alternatives to an existing 12.8 MW single-flash geothermal power plant shows that double-flash, binary, and combined flash/binary designs can increase the

A Techno-Economic Assessment of Hybrid Cooling Systems for Coal- and Natural-Gas-Fired Power Plants with and without Carbon Capture and Storage.

PubMed

Zhai, Haibo; Rubin, Edward S

2016-04-05

Advanced cooling systems can be deployed to enhance the resilience of thermoelectric power generation systems. This study developed and applied a new power plant modeling option for a hybrid cooling system at coal- or natural-gas-fired power plants with and without amine-based carbon capture and storage (CCS) systems. The results of the plant-level analyses show that the performance and cost of hybrid cooling systems are affected by a range of environmental, technical, and economic parameters. In general, when hot periods last the entire summer, the wet unit of a hybrid cooling system needs to share about 30% of the total plant cooling load in order to minimize the overall system cost. CCS deployment can lead to a significant increase in the water use of hybrid cooling systems, depending on the level of CO2 capture. Compared to wet cooling systems, widespread applications of hybrid cooling systems can substantially reduce water use in the electric power sector with only a moderate increase in the plant-level cost of electricity generation.

Heat Pipes Cool Power Magnetics

NASA Technical Reports Server (NTRS)

Hansen, I.; Chester, M.; Luedke, E.

1983-01-01

Configurations originally developed for space use are effective in any orientation. Heat pipes integrated into high-power, high-frequency, highvoltage spaceflight magnetics reduce weight and improve reliability by lowering internal tempertures. Two heat pipes integrated in design of power transformer cool unit in any orientation. Electrostatic shield conducts heat from windings to heat pipe evaporator. Technology allows dramatic reductions in size and weight, while significantly improving reliability. In addition, all attitude design of heat pipes allows operation of heat pipes independent of local gravity forces.

Improved lifetime of chitosan film in converting water vapor to electrical power by adding carboxymethyl cellulose

NASA Astrophysics Data System (ADS)

Nasution, T. I.; Balyan, M.; Nainggolan, I.

2018-02-01

A Water vapor cell based on chitosan film has been successfully fabricated in film form to convert water vapor to electrical power. In order to improve the lifetime of water vapor cell, Carboxymethyl Cellulose (CMC) was added into 1% chitosan solution within concentration variations of 0.01, 0.05, 0.1 and 0.5%. The result showed that the lifetime of water vapor cell increased higher by adding the higher concentration of Carboxymethyl cellulose. The highest lifetime was evidenced by adding 0.5%CMC which maintained for 48 weeks. However, the average electrical power became lower to 4.621 µW. This electrical power lower than the addition of 0.1%CMC which maintained for 5.167 µW. While, the lifetime of chitosan-0.1%CMC film of 44 weeks is shorter compared to chitosan-0.5%CMC film. Based on FTIR characterization, it was founded that the chitosan structure did not change until the addition of 0.1%CMC. This caused the electrical power of water vapor cell degenerated. Therefore, chitosan-0.5%CMC film has excellent lifetime in converting water vapor to electrical power.

Numerical investigation of mist/air impingement cooling on ribbed blade leading-edge surface.

PubMed

Bian, Qingfei; Wang, Jin; Chen, Yi-Tung; Wang, Qiuwang; Zeng, Min

2017-12-01

The working gas turbine blades are exposed to the environment of high temperature, especially in the leading-edge region. The mist/air two-phase impingement cooling has been adopted to enhance the heat transfer on blade surfaces and investigate the leading-edge cooling effectiveness. An Euler-Lagrange particle tracking method is used to simulate the two-phase impingement cooling on the blade leading-edge. The mesh dependency test has been carried out and the numerical method is validated based on the available experimental data of mist/air cooling with jet impingement on a concave surface. The cooling effectiveness on three target surfaces is investigated, including the smooth and the ribbed surface with convex/concave columnar ribs. The results show that the cooling effectiveness of the mist/air two-phase flow is better than that of the single-phase flow. When the ribbed surfaces are used, the heat transfer enhancement is significant, the surface cooling effectiveness becomes higher and the convex ribbed surface presents a better performance. With the enhancement of the surface heat transfer, the pressure drop in the impingement zone increases, but the incremental factor of the flow friction is smaller than that of the heat transfer enhancement. Copyright © 2017 Elsevier Ltd. All rights reserved.

14 CFR 23.1045 - Cooling test procedures for turbine engine powered airplanes.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Cooling test procedures for turbine engine powered airplanes. 23.1045 Section 23.1045 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Powerplant Cooling § 23.1045 Cooling test procedures for turbine engine powered...

14 CFR 23.1045 - Cooling test procedures for turbine engine powered airplanes.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling test procedures for turbine engine powered airplanes. 23.1045 Section 23.1045 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Powerplant Cooling § 23.1045 Cooling test procedures for turbine engine powered...

Acoustically-Enhanced Direct Contact Vapor Bubble Condensation

NASA Astrophysics Data System (ADS)

Boziuk, Thomas; Smith, Marc; Glezer, Ari

2017-11-01

Rate-limited, direct contact vapor condensation of vapor bubbles that are formed by direct steam injection through a nozzle in a quiescent subcooled liquid bath is accelerated using ultrasonic (MHz-range) actuation. A submerged, low power actuator produces an acoustic beam whose radiation pressure deforms the liquid-vapor interface, leading to the formation of a liquid spear that penetrates the vapor bubble to form a vapor torus with a significantly larger surface area and condensation rate. Ultrasonic focusing along the spear leads to the ejection of small, subcooled droplets through the vapor volume that impact the vapor-liquid interface and further enhance the condensation. High-speed Schlieren imaging of the formation and collapse of the vapor bubbles in the absence and presence of actuation shows that the impulse associated with the collapse of the toroidal volume leads to the formation of a turbulent vortex ring in the liquid phase. Liquid motions near the condensing vapor volume are investigated in the absence and presence of acoustic actuation using high-magnification PIV and show the evolution of a liquid jet through the center of the condensing toroidal volume and the formation and advection of vortex ring structures whose impulse appear to increase with temperature difference between the liquid and vapor phases. High-speed image processing is used to assess the effect of the actuation on the temporal and spatial variations in the characteristic scales and condensation rates of the vapor bubbles.

Inverter power module with distributed support for direct substrate cooling

DOEpatents

Miller, David Harold [San Pedro, CA; Korich, Mark D [Chino Hills, CA; Ward, Terence G [Redondo Beach, CA; Mann, Brooks S [Redondo Beach, CA

2012-08-21

Systems and/or methods are provided for an inverter power module with distributed support for direct substrate cooling. An inverter module comprises a power electronic substrate. A first support frame is adapted to house the power electronic substrate and has a first region adapted to allow direct cooling of the power electronic substrate. A gasket is interposed between the power electronic substrate and the first support frame. The gasket is configured to provide a seal between the first region and the power electronic substrate. A second support frame is adapted to house the power electronic substrate and joined to the first support frame to form the seal.

Thermoelectric Devices Cool, Power Electronics

NASA Technical Reports Server (NTRS)

2009-01-01

Nextreme Thermal Solutions Inc., based in Research Triangle Park, North Carolina, licensed thermoelectric technology from NASA s Jet Propulsion Laboratory. This has allowed the company to develop cutting edge, thin-film thermoelectric coolers that effective remove heat generated by increasingly powerful and tightly packed microchip components. These solid-state coolers are ideal solutions for applications like microprocessors, laser diodes, LEDs, and even potentially for cooling the human body. Nextreme s NASA technology has also enabled the invention of thermoelectric generators capable of powering technologies like medical implants and wireless sensor networks.

Floating Loop System For Cooling Integrated Motors And Inverters Using Hot Liquid Refrigerant

DOEpatents

Hsu, John S [Oak Ridge, TN; Ayers, Curtis W [Kingston, TN; Coomer, Chester [Knoxville, TN; Marlino, Laura D [Oak Ridge, TN

2006-02-07

A floating loop vehicle component cooling and air-conditioning system having at least one compressor for compressing cool vapor refrigerant into hot vapor refrigerant; at least one condenser for condensing the hot vapor refrigerant into hot liquid refrigerant by exchanging heat with outdoor air; at least one floating loop component cooling device for evaporating the hot liquid refrigerant into hot vapor refrigerant; at least one expansion device for expanding the hot liquid refrigerant into cool liquid refrigerant; at least one air conditioning evaporator for evaporating the cool liquid refrigerant into cool vapor refrigerant by exchanging heat with indoor air; and piping for interconnecting components of the cooling and air conditioning system.

Cooling technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salamon, Todd R; Vyas, Brijesh; Kota, Krishna

An apparatus and a method are provided. Use is made of a wick structure configured to receive a liquid and generate vapor in when such wick structure is heated by heat transferred from heat sources to be cooled off. A vapor channel is provided configured to receive the vapor generated and direct said vapor away from the wick structure. In some embodiments, heat conductors are used to transfer the heat from the heat sources to the liquid in the wick structure.

Calibrated vapor generator source

DOEpatents

Davies, John P.; Larson, Ronald A.; Goodrich, Lorenzo D.; Hall, Harold J.; Stoddard, Billy D.; Davis, Sean G.; Kaser, Timothy G.; Conrad, Frank J.

1995-01-01

A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet.

Calibrated vapor generator source

DOEpatents

Davies, J.P.; Larson, R.A.; Goodrich, L.D.; Hall, H.J.; Stoddard, B.D.; Davis, S.G.; Kaser, T.G.; Conrad, F.J.

1995-09-26

A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet. 10 figs.

Vapor phase pyrolysis

NASA Technical Reports Server (NTRS)

Steurer, Wolfgang

1992-01-01

The vapor phase pyrolysis process is designed exclusively for the lunar production of oxygen. In this concept, granulated raw material (soil) that consists almost entirely of metal oxides is vaporized and the vapor is raised to a temperature where it dissociates into suboxides and free oxygen. Rapid cooling of the dissociated vapor to a discrete temperature causes condensation of the suboxides, while the oxygen remains essentially intact and can be collected downstream. The gas flow path and flow rate are maintained at an optimum level by control of the pressure differential between the vaporization region and the oxygen collection system with the aid of the environmental vacuum.

Ice Thermal Storage Systems for LWR Supplemental Cooling and Peak Power Shifting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haihua Zhao; Hongbin Zhang; Phil Sharpe

2010-06-01

Availability of enough cooling water has been one of the major issues for the nuclear power plant site selection. Cooling water issues have frequently disrupted the normal operation at some nuclear power plants during heat waves and long draught. The issues become more severe due to the new round of nuclear power expansion and global warming. During hot summer days, cooling water leaving a power plant may become too hot to threaten aquatic life so that environmental regulations may force the plant to reduce power output or even temporarily to be shutdown. For new nuclear power plants to be builtmore » at areas without enough cooling water, dry cooling can be used to remove waste heat directly into the atmosphere. However, dry cooling will result in much lower thermal efficiency when the weather is hot. One potential solution for the above mentioned issues is to use ice thermal storage systems (ITS) that reduce cooling water requirements and boost the plant’s thermal efficiency in hot hours. ITS uses cheap off-peak electricity to make ice and uses those ice for supplemental cooling during peak demand time. ITS is suitable for supplemental cooling storage due to its very high energy storage density. ITS also provides a way to shift large amount of electricity from off peak time to peak time. Some gas turbine plants already use ITS to increase thermal efficiency during peak hours in summer. ITSs have also been widely used for building cooling to save energy cost. Among three cooling methods for LWR applications: once-through, wet cooling tower, and dry cooling tower, once-through cooling plants near a large water body like an ocean or a large lake and wet cooling plants can maintain the designed turbine backpressure (or condensation temperature) during 99% of the time; therefore, adding ITS to those plants will not generate large benefits. For once-through cooling plants near a limited water body like a river or a small lake, adding ITS can bring significant

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

NASA Technical Reports Server (NTRS)

Camarda, Charles J.; Glass, David E.

1992-01-01

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

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

NASA Astrophysics Data System (ADS)

Camarda, Charles J.; Glass, David E.

1992-10-01

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

Demonstration of passively cooled high-power Yb fiber amplifier

NASA Astrophysics Data System (ADS)

Bradford, Joshua; Cook, Justin; Antonio-Lopez, Jose Enrique; Shah, Larry; Amezcua Correa, Rodrigo; Richardson, Martin

2018-02-01

This work investigates the feasibility of passive cooling in high-power Yb amplifiers. Experimentally, an all-glass airclad step-index (ACSI) amplifier is diode-pumped with 400W and provides 200W power levels. With only natural convection to extract heat, core temperatures are estimated near 130°C with no degradation of performance relative to cooled architectures. Further, advanced analysis techniques allow for core temperature determination using thermal interferometry without the need for complicated stabilization or calibration.

System Analysis for Decay Heat Removal in Lead-Bismuth Cooled Natural Circulated Reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takaaki Sakai; Yasuhiro Enuma; Takashi Iwasaki

2002-07-01

Decay heat removal analyses for lead-bismuth cooled natural circulation reactors are described in this paper. A combined multi-dimensional plant dynamics code (MSG-COPD) has been developed to conduct the system analysis for the natural circulation reactors. For the preliminary study, transient analysis has been performed for a 100 MWe lead-bismuth-cooled reactor designed by Argonne National Laboratory (ANL). In addition, decay heat removal characteristics of a 400 MWe lead-bismuth-cooled natural circulation reactor designed by Japan Nuclear Cycle Development Institute (JNC) has been evaluated by using MSG-COPD. PRACS (Primary Reactor Auxiliary Cooling System) is prepared for the JNC's concept to get sufficient heatmore » removal capacity. During 2000 sec after the transient, the outlet temperature shows increasing tendency up to the maximum temperature of 430 Centigrade, because the buoyancy force in a primary circulation path is temporary reduced. However, the natural circulation is recovered by the PRACS system and the out let temperature decreases successfully. (authors)« less

System Analysis for Decay Heat Removal in Lead-Bismuth-Cooled Natural-Circulation Reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakai, Takaaki; Enuma, Yasuhiro; Iwasaki, Takashi

2004-03-15

Decay heat removal analyses for lead-bismuth-cooled natural-circulation reactors are described in this paper. A combined multidimensional plant dynamics code (MSG-COPD) has been developed to conduct the system analysis for the natural-circulation reactors. For the preliminary study, transient analysis has been performed for a 300-MW(thermal) lead-bismuth-cooled reactor designed by Argonne National Laboratory. In addition, decay heat removal characteristics of a 400-MW(electric) lead-bismuth-cooled natural-circulation reactor designed by the Japan Nuclear Cycle Development Institute (JNC) has been evaluated by using MSG-COPD. The primary reactor auxiliary cooling system (PRACS) is prepared for the JNC concept to get sufficient heat removal capacity. During 2000 smore » after the transient, the outlet temperature shows increasing tendency up to the maximum temperature of 430 deg. C because the buoyancy force in a primary circulation path is temporarily reduced. However, the natural circulation is recovered by the PRACS system, and the outlet temperature decreases successfully.« less

Power electronics substrate for direct substrate cooling

DOEpatents

Le, Khiet [Mission Viejo, CA; Ward, Terence G [Redondo Beach, CA; Mann, Brooks S [Redondo Beach, CA; Yankoski, Edward P [Corona, CA; Smith, Gregory S [Woodland Hills, CA

2012-05-01

Systems and apparatus are provided for power electronics substrates adapted for direct substrate cooling. A power electronics substrate comprises a first surface configured to have electrical circuitry disposed thereon, a second surface, and a plurality of physical features on the second surface. The physical features are configured to promote a turbulent boundary layer in a coolant impinged upon the second surface.

Heat transfer and material temperature conditions in the leading edge area of impingement-cooled turbine vanes

NASA Astrophysics Data System (ADS)

Berg, H. P.; Pfaff, K.; Hennecke, D. K.

The resultant effects on the cooling effectiveness at the leading edge area of an impingement-cooled turbine vane by varying certain geometrical parameters is described with reference to local internal heat transfer coefficients determined from experiment and temperature calculations. The local heat transfer on the cooling-air side is determined experimentally with the aid of the analogy between heat- and mass transfer. The impingement cooling is provided from an inserted sheet-metal containing a single row of holes. The Reynolds Number and several of the cooling geometry parameters were varied. The results demonstrate the high local resolution of the method of measurement, which allows improved analytical treatment of the leading-edge cooling configuration. These experiments also point to the necessity of not always performing model tests under idealized conditions. This becomes very clear in the case of the tests performed on an application-oriented impingement-cooling configuration like that often encountered in engine manufacture. In conclusion, as an example, temperature calculations are employed to demonstrate the effect on the cooling effectiveness of varying the distances between insert and inner surface of the leading edge. It shows how the effectiveness of the leading edge cooling can be increased by simple geometrical measures, which results in a considerable improvement in service life.

Modeling Single-Phase and Boiling Liquid Jet Impingement Cooling in Power Electronics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narumanchi, S. V. J.; Hassani, V.; Bharathan, D.

2005-12-01

Jet impingement has been an attractive cooling option in a number of industries over the past few decades. Over the past 15 years, jet impingement has been explored as a cooling option in microelectronics. Recently, interest has been expressed by the automotive industry in exploring jet impingement for cooling power electronics components. This technical report explores, from a modeling perspective, both single-phase and boiling jet impingement cooling in power electronics, primarily from a heat transfer viewpoint. The discussion is from the viewpoint of the cooling of IGBTs (insulated-gate bipolar transistors), which are found in hybrid automobile inverters.

Axicon based conical resonators with high power copper vapor laser.

PubMed

Singh, Bijendra; Subramaniam, V V; Daultabad, S R; Chakraborty, Ashim

2010-07-01

We report for the first time the performance of axicon based conical resonators (ABCRs) in a copper vapor laser, with novel results. The unstable conical resonator comprising of conical mirror (reflecting axicon) with axicon angle approximately pi/18, cone angle approximately 160 degrees, and a convex mirror of 60 cm radius of curvature was effective in reducing the average beam divergence to approximately 0.15 mrad (approximately 25 fold reduction compared to standard multimode plane-plane cavity) with output power of approximately 31 W. Extraction efficiency of approximately 50%-60% and beam divergence of <1 mrad was achieved in other stable ABCR configurations using flat and concave mirrors with the axicon. This is a significant improvement compared to 4-5 mrad normally observed in conventional stable resonators in copper vapor lasers. The conical resonators with copper vapor laser provide high misalignment tolerance beta approximately 4-5 mrad where beta is the tilt angle of the conical mirror from optimum position responsible for approximately 20% decline in laser power. The depth of focus d was approximately three times larger in case of conical resonator as compared to that of standard spherical unstable resonator under similar beam divergence and focusing conditions.

Sub-cooled liquid nitrogen cryogenic system with neon turbo-refrigerator for HTS power equipment

NASA Astrophysics Data System (ADS)

Yoshida, S.; Hirai, H.; Nara, N.; Ozaki, S.; Hirokawa, M.; Eguchi, T.; Hayashi, H.; Iwakuma, M.; Shiohara, Y.

2014-01-01

We developed a prototype sub-cooled liquid nitrogen (LN) circulation system for HTS power equipment. The system consists of a neon turbo-Brayton refrigerator with a LN sub-cooler and LN circulation pump unit. The neon refrigerator has more than 2 kW cooling power at 65 K. The LN sub-cooler is a plate-fin type heat exchanger and is installed in a refrigerator cold box. In order to carry out the system performance tests, a dummy cryostat having an electric heater was set instead of a HTS power equipment. Sub-cooled LN is delivered into the sub-cooler by the LN circulation pump and cooled within it. After the sub-cooler, sub-cooled LN goes out from the cold box to the dummy cryostat, and comes back to the pump unit. The system can control an outlet sub-cooled LN temperature by adjusting refrigerator cooling power. The refrigerator cooling power is automatically controlled by the turbo-compressor rotational speed. In the performance tests, we increased an electric heater power from 200 W to 1300 W abruptly. We confirmed the temperature fluctuation was about ±1 K. We show the cryogenic system details and performance test results in this paper.

Liquid cooled counter flow turbine bucket

DOEpatents

Dakin, James T.

1982-09-21

Means and a method are provided whereby liquid coolant flows radially outward through coolant passages in a liquid cooled turbine bucket under the influence of centrifugal force while in contact with countercurrently flowing coolant vapor such that liquid is entrained in the flow of vapor resulting in an increase in the wetted cooling area of the individual passages.

Perspective: Highly stable vapor-deposited glasses

NASA Astrophysics Data System (ADS)

Ediger, M. D.

2017-12-01

This article describes recent progress in understanding highly stable glasses prepared by physical vapor deposition and provides perspective on further research directions for the field. For a given molecule, vapor-deposited glasses can have higher density and lower enthalpy than any glass that can be prepared by the more traditional route of cooling a liquid, and such glasses also exhibit greatly enhanced kinetic stability. Because vapor-deposited glasses can approach the bottom of the amorphous part of the potential energy landscape, they provide insights into the properties expected for the "ideal glass." Connections between vapor-deposited glasses, liquid-cooled glasses, and deeply supercooled liquids are explored. The generality of stable glass formation for organic molecules is discussed along with the prospects for stable glasses of other types of materials.

Perspective: Highly stable vapor-deposited glasses

DOE PAGES

Ediger, M. D.

2017-12-07

This paper describes recent progress in understanding highly stable glasses prepared by physical vapor deposition and provides perspective on further research directions for the field. For a given molecule, vapor-deposited glasses can have higher density and lower enthalpy than any glass that can be prepared by the more traditional route of cooling a liquid, and such glasses also exhibit greatly enhanced kinetic stability. Because vapor-deposited glasses can approach the bottom of the amorphous part of the potential energy landscape, they provide insights into the properties expected for the “ideal glass”. Connections between vapor-deposited glasses, liquid-cooled glasses, and deeply supercooled liquidsmore » are explored. The generality of stable glass formation for organic molecules is discussed along with the prospects for stable glasses of other types of materials.« less

Perspective: Highly stable vapor-deposited glasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ediger, M. D.

This paper describes recent progress in understanding highly stable glasses prepared by physical vapor deposition and provides perspective on further research directions for the field. For a given molecule, vapor-deposited glasses can have higher density and lower enthalpy than any glass that can be prepared by the more traditional route of cooling a liquid, and such glasses also exhibit greatly enhanced kinetic stability. Because vapor-deposited glasses can approach the bottom of the amorphous part of the potential energy landscape, they provide insights into the properties expected for the “ideal glass”. Connections between vapor-deposited glasses, liquid-cooled glasses, and deeply supercooled liquidsmore » are explored. The generality of stable glass formation for organic molecules is discussed along with the prospects for stable glasses of other types of materials.« less

A Burst Mode, Ultrahigh Temperature UF4 Vapor Core Reactor Rankine Cycle Space Power System Concept

NASA Technical Reports Server (NTRS)

Dugan, E. T.; Kahook, S. D.; Diaz, N. J.

1996-01-01

Static and dynamic neutronic analyses have been performed on an innovative burst mode (100's of MW output for a few thousand seconds) Ulvahigh Temperature Vapor Core Reactor (UTVR) space nuclear power system. The NVTR employs multiple, neutronically-coupled fissioning cores and operates on a direct, closed Rankine cycle using a disk Magnetohydrodynamic (MHD) generater for energy conversion. The UTVR includes two types of fissioning core regions: (1) the central Ultrahigh Temperature Vapor Core (UTVC) which contains a vapor mixture of highly enriched UF4 fuel and a metal fluoride working fluid and (2) the UF4 boiler column cores located in the BeO moderator/reflector region. The gaseous nature of the fuel the fact that the fuel is circulating, the multiple coupled fissioning cores, and the use of a two phase fissioning fuel lead to unique static and dynamic neutronic characteristics. Static neutronic analysis was conducted using two-dimensional S sub n, transport theory calculations and three-dimensional Monte Carlo transport theory calculations. Circulating-fuel, coupled-core point reactor kinetics equations were used for analyzing the dynamic behavior of the UTVR. In addition to including reactivity feedback phenomena associated with the individual fissioning cores, the effects of core-to-core neutronic and mass flow coupling between the UTVC and the surrounding boiler cores were also included in the dynamic model The dynamic analysis of the UTVR reveals the existence of some very effectlve inherent reactivity feedback effects that are capable of quickly stabilizing this system, within a few seconds, even when large positive reactivity insertions are imposed. If the UTVC vapor fuel density feedback is suppressed, the UTVR is still inherently stable because of the boiler core liquid-fuel volume feedback; in contrast, suppression of the vapor fuel density feedback in 'conventional" gas core cavity reactors causes them to become inherently unstable. Due to the

Reliability and Maintainability Data for Lead Lithium Cooling Systems

DOE PAGES

Cadwallader, Lee

2016-11-16

This article presents component failure rate data for use in assessment of lead lithium cooling systems. Best estimate data applicable to this liquid metal coolant is presented. Repair times for similar components are also referenced in this work. These data support probabilistic safety assessment and reliability, availability, maintainability and inspectability analyses.

Experimental Study on Active Cooling Systems Used for Thermal Management of High-Power Multichip Light-Emitting Diodes

PubMed Central

2014-01-01

The objective of this study was to develop suitable cooling systems for high-power multichip LEDs. To this end, three different active cooling systems were investigated to control the heat generated by the powering of high-power multichip LEDs in two different configurations (30 and 2 × 15 W). The following cooling systems were used in the study: an integrated multi-fin heat sink design with a fan, a cooling system with a thermoelectric cooler (TEC), and a heat pipe cooling device. According to the results, all three systems were observed to be sufficient for cooling high-power LEDs. Furthermore, it was observed that the integrated multifin heat sink design with a fan was the most efficient cooling system for a 30 W high-power multichip LED. The cooling system with a TEC and 46 W input power was the most efficient cooling system for 2 × 15 W high-power multichip LEDs. PMID:25162058

14 CFR 23.1045 - Cooling test procedures for turbine engine powered airplanes.

Code of Federal Regulations, 2014 CFR

2014-01-01

... powered airplanes. 23.1045 Section 23.1045 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Powerplant Cooling § 23.1045 Cooling test procedures for turbine engine powered airplanes. (a) Compliance with § 23.1041 must be shown for all phases of operation. The airplane must be...

14 CFR 23.1045 - Cooling test procedures for turbine engine powered airplanes.

Code of Federal Regulations, 2012 CFR

2012-01-01

... powered airplanes. 23.1045 Section 23.1045 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Powerplant Cooling § 23.1045 Cooling test procedures for turbine engine powered airplanes. (a) Compliance with § 23.1041 must be shown for all phases of operation. The airplane must be...

14 CFR 23.1045 - Cooling test procedures for turbine engine powered airplanes.

Code of Federal Regulations, 2013 CFR

2013-01-01

... powered airplanes. 23.1045 Section 23.1045 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... CATEGORY AIRPLANES Powerplant Cooling § 23.1045 Cooling test procedures for turbine engine powered airplanes. (a) Compliance with § 23.1041 must be shown for all phases of operation. The airplane must be...

77 FR 73056 - Initial Test Programs for Water-Cooled Nuclear Power Plants

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-07

... NUCLEAR REGULATORY COMMISSION [NRC-2012-0293] Initial Test Programs for Water-Cooled Nuclear Power... (DG), DG-1259, ``Initial Test Programs for Water-Cooled Nuclear Power Plants.'' This guide describes the general scope and depth that the staff of the NRC considers acceptable for Initial Test Programs...

The Design of the Trading Mechanism to Adapt the Development of Mixed Cooling Heating and Power

NASA Astrophysics Data System (ADS)

Liu, D. N.; Li, Z. H.; Zhou, H. M.; Zhao, Q.; Xu, X. F.

2017-08-01

The enterprise who has combined cooling heating and power system has both the customer group and the power generation resources. Therefore, it can be used as a power user, and can also be used as a power generation enterprise to participate in the direct purchase of electricity. This paper combines characteristics of mixed cooling heating and power, designs application business model of mixed cooling heating and power, and puts forward to the scene of cooling heating and power trading scheme, helping the enterprise according to the power supply and demand situation in the region adjust their positions and participate in the electricity market.

Nonlinear response of tropical lower-stratospheric temperature and water vapor to ENSO

NASA Astrophysics Data System (ADS)

Garfinkel, Chaim I.; Gordon, Amit; Oman, Luke D.; Li, Feng; Davis, Sean; Pawson, Steven

2018-04-01

A series of simulations using the NASA Goddard Earth Observing System Chemistry-Climate Model are analyzed in order to aid in the interpretation of observed interannual and sub-decadal variability in the tropical lower stratosphere over the past 35 years. The impact of El Niño-Southern Oscillation on temperature and water vapor in this region is nonlinear in boreal spring. While moderate El Niño events lead to cooling in this region, strong El Niño events lead to warming, even as the response of the large-scale Brewer-Dobson circulation appears to scale nearly linearly with El Niño. This nonlinearity is shown to arise from the response in the Indo-West Pacific to El Niño: strong El Niño events lead to tropospheric warming extending into the tropical tropopause layer and up to the cold point in this region, where it allows for more water vapor to enter the stratosphere. The net effect is that both strong La Niña and strong El Niño events lead to enhanced entry water vapor and stratospheric moistening in boreal spring and early summer. These results lead to the following interpretation of the contribution of sea surface temperatures to the decline in water vapor in the early 2000s: the very strong El Niño event in 1997/1998, followed by more than 2 consecutive years of La Niña, led to enhanced lower-stratospheric water vapor. As this period ended in early 2001, entry water vapor concentrations declined. This effect accounts for approximately one-quarter of the observed drop.

Developments on GM-Type Pulse Tube Cryorefrigerators with Large Cooling Power

NASA Astrophysics Data System (ADS)

Köttig, T.; Waldauf, A.; Thürk, M.; Seidel, P.

2004-06-01

Over the past several years the authors have participated in basic and prototype developments of four valve pulse tube refrigerators (FVPTR). Systematic studies have been carried out to characterize the basics of energy transport mechanisms, the flow distribution and loss mechanisms of this type of pulse tube refrigerator (PTR) with its active type of phase shifting. Based on the comprehension of these phenomena, several prototypes have been built and optimized for various applications. Recently a single-stage PTR in coaxial arrangement has been designed for maximum refrigeration power in the temperature range between 20 and 80 K limited by an available electrical input power of 7 kW. To reach this goal we used lead screens in the coldest part of the regenerator instead of spheres in order to decrease the pressure drop. The improvement of the regenerator prevents the reported fact that at higher temperatures the performance of a pulse tube with a regenerator partially filled with lead spheres can even be worse than a regenerator totally made of stainless steel. At the moment the cooler provides a cooling power of 120 W@74 K and 40 W@34 K. The minimum no-load temperature achieved is 18.6 K.

Upstream Density for Plasma Detachment with Conventional and Lithium Vapor-Box Divertors

NASA Astrophysics Data System (ADS)

Goldston, Rj; Schwartz, Ja

2016-10-01

Fusion power plants are likely to require detachment of the divertor plasma from material targets. The lithium vapor box divertor is designed to achieve this, while limiting the flux of lithium vapor to the main plasma. We develop a simple model of near-detachment to evaluate the required upstream plasma density, for both conventional and lithium vapor-box divertors, based on particle and dynamic pressure balance between up- and down-stream, at near-detachment conditions. A remarkable general result is found, not just for lithium-induced detachment, that the upstream density divided by the Greenwald-limit density scales as (P 5 / 8 /B 3 / 8) Tdet1 / 2 / (ɛcool + γTdet) , with no explicit size scaling. Tdet is the temperature just before strong pressure loss, 1/2 of the ionization potential of the dominant recycling species, ɛcool is the average plasma energy lost per injected hydrogenic and impurity atom, and γ is the sheath heat transmission factor. A recent 1-D calculation agrees well with this scaling. The implication is that the plasma exhaust problem cannot be solved by increasing R. Instead significant innovation, such as the lithium vapor box divertor, will be required. This work supported by DOE Contract No. DE-AC02-09CH11466.

The temporal power spectrum of atmospheric fluctuations due to water vapor

NASA Astrophysics Data System (ADS)

Lay, O. P.

1997-05-01

Irregular variations in the refractivity of the atmosphere cause fluctuations in the phase measured by interferometers, limiting the spatial resolution that can be obtained. For frequencies up to the far infrared, water vapor is the dominant cause of the variations. The temporal power spectrum of the phase fluctuations is needed to assess correction schemes such as phase referencing using a nearby calibrator and water vapor radiometry. A model is developed for the temporal power spectrum of phase fluctuations measured by an interferometer through a layer of Kolmogorov turbulence of arbitrary thickness. It is found that both the orientation of the baseline with respect to the wind direction and the elevation of the observations can have a large effect on the temporal power spectrum. Plots of the spectral density distribution, where the area under the curve is proportional to phase power, show that substantial contributions from length scales as long as 100 times the interferometer baseline are possible. The model is generally consistent with data from the 12-GHz phase monitor at the Owens Valley Radio Observatory, and allows the data to be extrapolated to an arbitrary baseline, observing frequency and elevation. There is some evidence that there can be more than one component of turbulence present at a given time for the Owens Valley. The validity of the frozen turbulence assumption and the geometrical optics approximation is discussed and found to be reasonable under most conditions. The models and data presented here form the basis of an analysis of phase calibration and water vapor radiometry \\cite[(Lay 1997)]{lay96}.

Lead telluride as a thermoelectric material for thermoelectric power generation

NASA Astrophysics Data System (ADS)

Dughaish, Z. H.

2002-09-01

The specialized applications of thermoelectric generators are very successful and have motivated a search for materials with an improved figure of merit Z, and also for materials which operate at elevated temperatures. Lead telluride, PbTe, is an intermediate thermoelectric power generator. Its maximum operating temperature is 900 K. PbTe has a high melting point, good chemical stability, low vapor pressure and good chemical strength in addition to high figure of merit Z. Recently, research in thermoelectricity aims to obtain new improved materials for autonomous sources of electrical power in specialized medical, terrestial and space applications and to obtain an unconventional energy source after the oil crises of 1974. Although the efficiency of thermoelectric generators is rather low, typically ∼5%, the other advantages, such as compactness, silent, reliability, long life, and long period of operation without attention, led to a wide range of applications. PbTe thermoelectric generators have been widely used by the US army, in space crafts to provide onboard power, and in pacemakers batteries. The general physical properties of lead telluride and factors affecting the figure of merit have been reviewed. Various possibilities of improving the figure of merit of the material have been given, including effect of grain size on reducing the lattice thermal conductivity λL. Comparison of some transport properties of lead telluride with other thermoelectric materials and procedures of preparing compacts with transport properties very close to the single crystal values from PbTe powder by cold and hot-pressing techniques are discussed.

Retrofit device to improve vapor compression cooling system performance by dynamic blower speed modulation

DOEpatents

Roth, Robert Paul; Hahn, David C.; Scaringe, Robert P.

2015-12-08

A device and method are provided to improve performance of a vapor compression system using a retrofittable control board to start up the vapor compression system with the evaporator blower initially set to a high speed. A baseline evaporator operating temperature with the evaporator blower operating at the high speed is recorded, and then the device detects if a predetermined acceptable change in evaporator temperature has occurred. The evaporator blower speed is reduced from the initially set high speed as long as there is only a negligible change in the measured evaporator temperature and therefore a negligible difference in the compressor's power consumption so as to obtain a net increase in the Coefficient of Performance.

Self-vapor cooled targets for production of I-123 at high current accelerators. [using Xe-123 production

NASA Technical Reports Server (NTRS)

Blue, J. W.; Scholz, K. L.; Sodd, V. J.

1974-01-01

The basic elements of the vapor cooled target system are shown. This system can be operated as a heat pipe or as a conventional condenser. The choice of target fluid is based on the specific nuclear reaction chosen to produce Xe-123. The reaction using I-127 was studied and shown to have a significant yield for bombarding energies from 47 to 63 MeV. The Cs-133 reaction is also included. Xenon-123 is applied to I-123 production in a purer form for thyroid studies.

Emissions-critical charge cooling using an organic rankine cycle

DOEpatents

Ernst, Timothy C.; Nelson, Christopher R.

2014-07-15

The disclosure provides a system including a Rankine power cycle cooling subsystem providing emissions-critical charge cooling of an input charge flow. The system includes a boiler fluidly coupled to the input charge flow, an energy conversion device fluidly coupled to the boiler, a condenser fluidly coupled to the energy conversion device, a pump fluidly coupled to the condenser and the boiler, an adjuster that adjusts at least one parameter of the Rankine power cycle subsystem to change a temperature of the input charge exiting the boiler, and a sensor adapted to sense a temperature characteristic of the vaporized input charge. The system includes a controller that can determine a target temperature of the input charge sufficient to meet or exceed predetermined target emissions and cause the adjuster to adjust at least one parameter of the Rankine power cycle to achieve the predetermined target emissions.

Film Cooled Recession of SiC/SiC Ceramic Matrix Composites: Test Development, CFD Modeling and Experimental Observations

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Sakowski, Barbara A.; Fisher, Caleb

2014-01-01

SiCSiC ceramic matrix composites (CMCs) systems will play a crucial role in next generation turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures, reduce engine weight and cooling requirements. However, the environmental stability of Si-based ceramics in high pressure, high velocity turbine engine combustion environment is of major concern. The water vapor containing combustion gas leads to accelerated oxidation and corrosion of the SiC based ceramics due to the water vapor reactions with silica (SiO2) scales forming non-protective volatile hydroxide species, resulting in recession of the ceramic components. Although environmental barrier coatings are being developed to help protect the CMC components, there is a need to better understand the fundamental recession behavior of in more realistic cooled engine component environments.In this paper, we describe a comprehensive film cooled high pressure burner rig based testing approach, by using standardized film cooled SiCSiC disc test specimen configurations. The SiCSiC specimens were designed for implementing the burner rig testing in turbine engine relevant combustion environments, obtaining generic film cooled recession rate data under the combustion water vapor conditions, and helping developing the Computational Fluid Dynamics (CFD) film cooled models and performing model validation. Factors affecting the film cooled recession such as temperature, water vapor concentration, combustion gas velocity, and pressure are particularly investigated and modeled, and compared with impingement cooling only recession data in similar combustion flow environments. The experimental and modeling work will help predict the SiCSiC CMC recession behavior, and developing durable CMC systems in complex turbine engine operating conditions.

The effects of leading edge and downstream film cooling on turbine vane heat transfer

NASA Astrophysics Data System (ADS)

Hylton, L. D.; Nirmalan, V.; Sultanian, B. K.; Kaufman, R. M.

1988-11-01

The progress under contract NAS3-24619 toward the goal of establishing a relevant data base for use in improving the predictive design capabilities for external heat transfer to turbine vanes, including the effect of downstream film cooling with and without leading edge showerhead film cooling. Experimental measurements were made in a two-dimensional cascade previously used to obtain vane surface heat transfer distributions on nonfilm cooled airfoils under contract NAS3-22761 and leading edge showerhead film cooled airfoils under contract NAS3-23695. The principal independent parameters (Mach number, Reynolds number, turbulence, wall-to-gas temperature ratio, coolant-to-gas temperature ratio, and coolant-to-gas pressure ratio) were maintained over ranges consistent with actual engine conditions and the test matrix was structured to provide an assessment of the independent influence of parameters of interest, namely, exit Mach number, exit Reynolds number, coolant-to-gas temperature ratio, and coolant-to-gas pressure ratio. Data provide a data base for downstream film cooled turbine vanes and extends the data bases generated in the two previous studies. The vane external heat transfer obtained indicate that considerable cooling benefits can be achieved by utilizing downstream film cooling. The data obtained and presented illustrate the interaction of the variables and should provide the airfoil designer and computational analyst the information required to improve heat transfer design capabilities for film cooled turbine airfoils.

The effects of leading edge and downstream film cooling on turbine vane heat transfer

NASA Technical Reports Server (NTRS)

Hylton, L. D.; Nirmalan, V.; Sultanian, B. K.; Kaufman, R. M.

1988-01-01

The progress under contract NAS3-24619 toward the goal of establishing a relevant data base for use in improving the predictive design capabilities for external heat transfer to turbine vanes, including the effect of downstream film cooling with and without leading edge showerhead film cooling. Experimental measurements were made in a two-dimensional cascade previously used to obtain vane surface heat transfer distributions on nonfilm cooled airfoils under contract NAS3-22761 and leading edge showerhead film cooled airfoils under contract NAS3-23695. The principal independent parameters (Mach number, Reynolds number, turbulence, wall-to-gas temperature ratio, coolant-to-gas temperature ratio, and coolant-to-gas pressure ratio) were maintained over ranges consistent with actual engine conditions and the test matrix was structured to provide an assessment of the independent influence of parameters of interest, namely, exit Mach number, exit Reynolds number, coolant-to-gas temperature ratio, and coolant-to-gas pressure ratio. Data provide a data base for downstream film cooled turbine vanes and extends the data bases generated in the two previous studies. The vane external heat transfer obtained indicate that considerable cooling benefits can be achieved by utilizing downstream film cooling. The data obtained and presented illustrate the interaction of the variables and should provide the airfoil designer and computational analyst the information required to improve heat transfer design capabilities for film cooled turbine airfoils.

A passive cooling system proposal for multifunction and high-power displays

NASA Astrophysics Data System (ADS)

Tari, Ilker

2013-03-01

Flat panel displays are conventionally cooled by internal natural convection, which constrains the possible rate of heat transfer from the panel. On one hand, during the last few years, the power consumption and the related cooling requirement for 1080p displays have decreased mostly due to energy savings by the switch to LED backlighting and more efficient electronics. However, on the other hand, the required cooling rate recently started to increase with new directions in the industry such as 3D displays, and ultra-high-resolution displays (recent 4K announcements and planned introduction of 8K). In addition to these trends in display technology itself, there is also a trend to integrate consumer entertainment products into displays with the ultimate goal of designing a multifunction device replacing the TV, the media player, the PC, the game console and the sound system. Considering the increasing power requirement for higher fidelity in video processing, these multifunction devices tend to generate very high heat fluxes, which are impossible to dissipate with internal natural convection. In order to overcome this obstacle, instead of active cooling with forced convection that comes with drawbacks of noise, additional power consumption, and reduced reliability, a passive cooling system relying on external natural convection and radiation is proposed here. The proposed cooling system consists of a heat spreader flat heat pipe and aluminum plate-finned heat sink with anodized surfaces. For this system, the possible maximum heat dissipation rates from the standard size panels (in 26-70 inch range) are estimated by using our recently obtained heat transfer correlations for the natural convection from aluminum plate-finned heat sinks together with the surface-to-surface radiation. With the use of the proposed passive cooling system, the possibility of dissipating very high heat rates is demonstrated, hinting a promising green alternative to active cooling.

Laser Cooling the Diatomic Molecule CaH

NASA Astrophysics Data System (ADS)

Velasquez, Joe, III; Di Rosa, Michael

2014-06-01

To laser-cool a species, a closed (or nearly closed) cycle is required to dissipate translational energy through many directed laser-photon absorption and subsequent randomly-directed spontaneous emission events. Many atoms lend themselves to such a closed-loop cooling cycle. Attaining laser-cooled molecular species is challenging because of their inherently complex internal structure, yet laser-cooling molecules could lead to studies in interesting chemical dynamics among other applications. Typically, laser-cooled atoms are assembled into molecules through photoassociation or Feschbach resonance. CaH is one of a few molecules whose internal structure is quite atom-like, allowing a nearly closed cycle without the need for many repumping lasers. We will also present our work-to-date on laser cooling this molecule. We employ traditional pulsed atomic/molecular beam techniques with a laser vaporization source to generate species with well-defined translational energies over a narrow range of velocity. In this way, we can apply laser-cooling to most species in the beam along a single dimension (the beam's axis). This project is funded by the LDRD program of the Los Alamos National Laboratory.

Data center cooling system

DOEpatents

Chainer, Timothy J; Dang, Hien P; Parida, Pritish R; Schultz, Mark D; Sharma, Arun

2015-03-17

A data center cooling system may include heat transfer equipment to cool a liquid coolant without vapor compression refrigeration, and the liquid coolant is used on a liquid cooled information technology equipment rack housed in the data center. The system may also include a controller-apparatus to regulate the liquid coolant flow to the liquid cooled information technology equipment rack through a range of liquid coolant flow values based upon information technology equipment temperature thresholds.

Carbon-based nanostructured surfaces for enhanced phase-change cooling

NASA Astrophysics Data System (ADS)

Selvaraj Kousalya, Arun

To maintain acceptable device temperatures in the new generation of electronic devices under development for high-power applications, conventional liquid cooling schemes will likely be superseded by multi-phase cooling solutions to provide substantial enhancement to the cooling capability. The central theme of the current work is to investigate the two-phase thermal performance of carbon-based nanostructured coatings in passive and pumped liquid-vapor phase-change cooling schemes. Quantification of the critical parameters that influence thermal performance of the carbon nanostructured boiling surfaces presented herein will lead to improved understanding of the underlying evaporative and boiling mechanisms in such surfaces. A flow boiling experimental facility is developed to generate consistent and accurate heat transfer performance curves with degassed and deionized water as the working fluid. New means of boiling heat transfer enhancement by altering surface characteristics such as surface energy and wettability through light-surface interactions is explored in this work. In this regard, carbon nanotube (CNT) coatings are exposed to low-intensity irradiation emitted from a light emitting diode and the subcooled flow boiling performance is compared against a non-irradiated CNT-coated copper surface. A considerable reduction in surface superheat and enhancement in average heat transfer coefficient is observed. In another work involving CNTs, the thermal performance of CNT-integrated sintered wick structures is evaluated in a passively cooled vapor chamber. A physical vapor deposition process is used to coat the CNTs with varying thicknesses of copper to promote surface wetting with the working fluid, water. Thermal performance of the bare sintered copper powder sample and the copper-functionalized CNT-coated sintered copper powder wick samples is compared using an experimental facility that simulates the capillary fluid feeding conditions of a vapor chamber

Potential Application of a Thermoelectric Generator in Passive Cooling System of Nuclear Power Plants

NASA Astrophysics Data System (ADS)

Wang, Dongqing; Liu, Yu; Jiang, Jin; Pang, Wei; Lau, Woon Ming; Mei, Jun

2017-05-01

In the design of nuclear power plants, various natural circulation passive cooling systems are considered to remove residual heat from the reactor core in the event of a power loss and maintain the plant's safety. These passive systems rely on gravity differences of fluids, resulting from density differentials, rather than using an external power-driven system. Unfortunately, a major drawback of such systems is their weak driving force, which can negatively impact safety. In such systems, there is a temperature difference between the heat source and the heat sink, which potentially offers a natural platform for thermoelectric generator (TEG) applications. While a previous study designed and analyzed a TEG-based passive core cooling system, this paper considers TEG applications in other passive cooling systems of nuclear power plants, after which the concept of a TEG-based passive cooling system is proposed. In such a system, electricity is produced using the system's temperature differences through the TEG, and this electricity is used to further enhance the cooling process.

Cooling options for high-average-power laser mirrors

NASA Astrophysics Data System (ADS)

Vojna, D.; Slezak, O.; Lucianetti, A.; Mocek, T.

2015-01-01

Thermally-induced deformations of steering mirrors reflecting 100 J/10 Hz laser pulses in vacuum have been analyzed. This deformation is caused by the thermal stress arisen due to parasitic absorption of 1 kW square-shaped flat-top laser beam in the dielectric multi-layer structure. Deformation depends on amount of absorbed power and geometry of the mirror as well as on the heat removal scheme. In our calculations, the following percentages of absorption of the incident power have been used: 1%, 0.5% and 0.1%. The absorbed power has been considered to be much higher than that expected in reality to assess the worst case scenario. Rectangular and circular mirrors made of zerodur (low thermal expansion glass) were considered for these simulations. The effect of coating layers on induced deformations has been neglected. Induced deformation of the mirror surface can significantly degrade the quality of the laser beam in the beam delivery system. Therefore, the proper design of the cooling scheme for the mirror in order to minimize the deformations is needed. Three possible cooling schemes of the mirror have been investigated. The first one takes advantage of a radiation cooling of the mirror and a copper heatsink fixed to the rear face of the mirror, the second scheme is based on additional heat conduction provided by flexible copper wires connected to the mirror holder, and the last scheme combines two above mentioned methods.

Effect of RANS-Type Turbulence Models on Adiabatic Film Cooling Effectiveness over a Scaled Up Gas Turbine Blade Leading Edge Surface

NASA Astrophysics Data System (ADS)

Yepuri, Giridhara Babu; Talanki Puttarangasetty, Ashok Babu; Kolke, Deepak Kumar; Jesuraj, Felix

2016-06-01

Increasing the gas turbine inlet temperature is one of the key technologies in raising gas turbine engine power output. Film cooling is one of the efficient cooling techniques to cool the hot section components of a gas turbine engines in turn the turbine inlet temperature can be increased. This study aims at investigating the effect of RANS-type turbulence models on adiabatic film cooling effectiveness over a scaled up gas turbine blade leading edge surfaces. For the evaluation, five different two equation RANS-type turbulent models have been taken in consideration, which are available in the ANSYS-Fluent. For this analysis, the gas turbine blade leading edge configuration is generated using Solid Works. The meshing is done using ANSYS-Workbench Mesh and ANSYS-Fluent is used as a solver to solve the flow field. The considered gas turbine blade leading edge model is having five rows of film cooling circular holes, one at stagnation line and the two each on either side of stagnation line at 30° and 60° respectively. Each row has the five holes with the hole diameter of 4 mm, pitch of 21 mm arranged in staggered manner and has the hole injection angle of 30° in span wise direction. The experiments are carried in a subsonic cascade tunnel facility at heat transfer lab of CSIR-National Aerospace Laboratory with a Reynolds number of 1,00,000 based on leading edge diameter. From the Computational Fluid Dynamics (CFD) evaluation it is found that K-ɛ Realizable model gives more acceptable results with the experimental values, compared to the other considered turbulence models for this type of geometries. Further the CFD evaluated results, using K-ɛ Realizable model at different blowing ratios are compared with the experimental results.

Removal of hydrogen sulfide as ammonium sulfate from hydropyrolysis product vapors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marker, Terry L.; Felix, Larry G.; Linck, Martin B.

A system and method for processing biomass into hydrocarbon fuels that includes processing a biomass in a hydropyrolysis reactor resulting in hydrocarbon fuels and a process vapor stream and cooling the process vapor stream to a condensation temperature resulting in an aqueous stream. The aqueous stream is sent to a catalytic reactor where it is oxidized to obtain a product stream containing ammonia and ammonium sulfate. A resulting cooled product vapor stream includes non-condensable process vapors comprising H.sub.2, CH.sub.4, CO, CO.sub.2, ammonia and hydrogen sulfide.

Removal of hydrogen sulfide as ammonium sulfate from hydropyrolysis product vapors

DOEpatents

Marker, Terry L; Felix, Larry G; Linck, Martin B; Roberts, Michael J

2014-10-14

A system and method for processing biomass into hydrocarbon fuels that includes processing a biomass in a hydropyrolysis reactor resulting in hydrocarbon fuels and a process vapor stream and cooling the process vapor stream to a condensation temperature resulting in an aqueous stream. The aqueous stream is sent to a catalytic reactor where it is oxidized to obtain a product stream containing ammonia and ammonium sulfate. A resulting cooled product vapor stream includes non-condensable process vapors comprising H.sub.2, CH.sub.4, CO, CO.sub.2, ammonia and hydrogen sulfide.

Heat pipe cooling of power processing magnetics

NASA Technical Reports Server (NTRS)

Hansen, I. G.; Chester, M. S.

1979-01-01

A heat pipe cooled transformer and input filter were developed for the 2.4 kW beam supply of a 30 cm ion thruster system. This development yielded a mass reduction of 40% (1.76 kg) and lower mean winding temperature (20 C lower). While these improvements are significant, preliminary designs predict even greater benefits to be realized at higher power. The design details are presented along with the results of thermal vacuum operation and the component performance in a 3 kW breadboard power processor.

High average power magnetic modulator for metal vapor lasers

DOEpatents

Ball, Don G.; Birx, Daniel L.; Cook, Edward G.; Miller, John L.

1994-01-01

A three-stage magnetic modulator utilizing magnetic pulse compression designed to provide a 60 kV pulse to a copper vapor laser at a 4.5 kHz repetition rate is disclosed. This modulator operates at 34 kW input power. The circuit includes a step up auto transformer and utilizes a rod and plate stack construction technique to achieve a high packing factor.

Experiments on solar photovoltaic power generation using concentrator and liquid cooling

NASA Technical Reports Server (NTRS)

Beam, B. H.; Hansen, C. F.

1975-01-01

Calculations and experimental data are presented leading to the development of a practical, economical solar photovoltaic power supply. The concept involves concentration of sunlight up to about 100 times normal solar intensity in a solar tracking collector and directing this to an array of solar cells. The cells are immersed in water circulated from a thermal reservoir which limits cell temperature rise to about 20 C above ambient during the day and which cools to ambient temperature during the night. Experiments were conducted on solar cells using a Fresnel lens for magnification, a telescope equatorial mount with clock drive, and tap water circulated through the solar cell holder cavity. Test results show that cells operate satisfactorily under these conditions. Power outputs achieved experimentally with cell optimized for 25 suns were linear with concentration to about 15 suns. Cells optimized for 100 suns were not available, but a corresponding linear relation of power output with concentration is anticipated. Test results have been used in a design analysis of the cost of systems utilizing this technique.

Marginal costs of water savings from cooling system retrofits: a case study for Texas power plants

NASA Astrophysics Data System (ADS)

Loew, Aviva; Jaramillo, Paulina; Zhai, Haibo

2016-10-01

The water demands of power plant cooling systems may strain water supply and make power generation vulnerable to water scarcity. Cooling systems range in their rates of water use, capital investment, and annual costs. Using Texas as a case study, we examined the cost of retrofitting existing coal and natural gas combined-cycle (NGCC) power plants with alternative cooling systems, either wet recirculating towers or air-cooled condensers for dry cooling. We applied a power plant assessment tool to model existing power plants in terms of their key plant attributes and site-specific meteorological conditions and then estimated operation characteristics of retrofitted plants and retrofit costs. We determined the anticipated annual reductions in water withdrawals and the cost-per-gallon of water saved by retrofits in both deterministic and probabilistic forms. The results demonstrate that replacing once-through cooling at coal-fired power plants with wet recirculating towers has the lowest cost per reduced water withdrawals, on average. The average marginal cost of water withdrawal savings for dry-cooling retrofits at coal-fired plants is approximately 0.68 cents per gallon, while the marginal recirculating retrofit cost is 0.008 cents per gallon. For NGCC plants, the average marginal costs of water withdrawal savings for dry-cooling and recirculating towers are 1.78 and 0.037 cents per gallon, respectively.

Stagnation region gas film cooling for turbine blade leading edge applications

NASA Technical Reports Server (NTRS)

Luckey, D. W.; Winstanley, D. K.; Hanus, G. J.; Lecuyer, M. R.

1976-01-01

An experimental investigation was conducted to model the film-cooling performance for a turbine-vane leading edge using the stagnation region of a cylinder in cross flow. Experiments were conducted with a single row of spanwise-angled coolant holes for a range of the coolant blowing ratio with a freestream-to-wall temperature ratio of about 2.1 and a Reynolds number of 170,000, characteristic of the gas-turbine environment. Data from local heat-flux measurements are presented for coolant-hole injection angles of 25, 35, and 45 deg with the row of holes located at three positions relative to the stagnation line on the cylinder. Results show the spanwise (hole-to-hole) variation of heat-flux reduction due to film cooling and indicate conditions for the optimum film-cooling performance.

Personal cooling in nuclear power stations. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamon, E.

1983-03-01

Two approaches to personal, non-restrictive cooling of workers exposed to high-temperature work environments in nuclear power plants were evaluated. Both approaches involved a cooling garment designed to be worn under the protective clothing donned in penetration into radiation areas. One garmet was developed to cool by direct body contact with small packets of frozen water enclosed in the pockets of a shirt. The other garmets cooled by circulating a cooled liquid through capillaries in a vest and head cap (System A) or a vest (System B). Testing was conducted in a laboratory simulation of high ambient temperature (55/sup 0/C) andmore » moderate metabolic heat production (200 to 300 kcal/h). Exposure time without cooling (control) was 52 minutes (Group 1) for the workloads demanding 200 kcal/h (48 minutes for Group 2). A long garmet with 7.2 kg of frozen water (LFWG) increased mean exposure time over the control by 242% (163% for the same garmet with 6.2 kg of frozen water). A short-version garmet with 3.8 kg of frozen water (SFWG) increased the stay time by 115%. The circulating-liquid garmets increased mean exposure time 35% (System A) and 27% (System B) over the control. In field observation, the LFWG with 6.2 kg of frozen water improved stay time by 125%.« less

Dynamics of manganese, cadmium, and lead in experimental power plant ponds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mathis, B.J.; Cummings, T.F.; Gower, M.

1977-06-01

This study was designed to determine the effect of heated power plant cooling water on the compartmentalization of manganese, lead, and cadmium in experimental ponds. Caged channel catfish and green sunfish were kept in an experimental pond and a control pond. Periodically, whole fishes, gill, heart, kidney, liver, and musculature were analyzed for the three metals. Concentrations of the three metals in fishes were not affected by the temperature differential maintained during the study. There was no correlation in concentrations of cadmium and lead with age (weight and length) of fishes but manganese concentrations declined slightly with age. Aquatic organismsmore » such as snails, fingernail clams, leeches, tubificid annelids, and dragonfly nymphs exhibited concentrations of cadmium higher than sediments while snails and duckweed more closely reflected concentrations of manganese in sediments.« less

Vapor intrusion risk of lead scavengers 1,2-dibromoethane (EDB) and 1,2-dichloroethane (DCA).

PubMed

Ma, Jie; Li, Haiyan; Spiese, Richard; Wilson, John; Yan, Guangxu; Guo, Shaohui

2016-06-01

Vapor intrusion of synthetic fuel additives represented a critical yet still neglected problem at sites impacted by petroleum fuel releases. This study used an advanced numerical model to simulate the vapor intrusion risk of lead scavengers 1,2-dibromoethane (ethylene dibromide, EDB) and 1,2-dichloroethane (DCA) under different site conditions. We found that simulated EDB and DCA indoor air concentrations can exceed USEPA screening level (4.7 × 10(-3) μg/m(3) for EDB and 1.1 × 10(-1) μg/m(3) for DCA) if the source concentration is high enough (is still within the concentration range found at leaking UST site). To evaluate the chance that vapor intrusion of EDB might exceed the USEPA screening levels for indoor air, the simulation results were compared to the distribution of EDB at leaking UST sites in the US. If there is no degradation of EDB or only abiotic degradation of EDB, from 15% to 37% of leaking UST sites might exceed the USEPA screening level. This study supports the statements made by USEPA in the Petroleum Vapor Intrusion (PVI) Guidance that the screening criteria for petroleum hydrocarbon may not provide sufficient protectiveness for fuel releases containing EDB and DCA. Based on a thorough literature review, we also compiled previous published data on the EDB and DCA groundwater source concentrations and their degradation rates. These data are valuable in evaluating EDB and DCA vapor intrusion risk. In addition, a set of refined attenuation factors based on site-specific information (e.g., soil types, source depths, and degradation rates) were provided for establishing site-specific screening criteria for EDB and DCA. Overall, this study points out that lead scavengers EDB and DCA may cause vapor intrusion problems. As more field data of EDB and DCA become available, we recommend that USEPA consider including these data in the existing PVI database and possibly revising the PVI Guidance as necessary. Copyright © 2016 Elsevier Ltd. All

Use of reclaimed water for power plant cooling.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veil, J. A.; Environmental Science Division

2007-10-16

Freshwater demands are steadily increasing throughout the United States. As its population increases, more water is needed for domestic use (drinking, cooking, cleaning, etc.) and to supply power and food. In arid parts of the country, existing freshwater supplies are not able to meet the increasing demands for water. New water users are often forced to look to alternative sources of water to meet their needs. Over the past few years, utilities in many locations, including parts of the country not traditionally water-poor (e.g., Georgia, Maryland, Massachusetts, New York, and North Carolina) have needed to reevaluate the availability of watermore » to meet their cooling needs. This trend will only become more extreme with time. Other trends are likely to increase pressure on freshwater supplies, too. For example, as populations increase, they will require more food. This in turn will likely increase demands for water by the agricultural sector. Another example is the recent increased interest in producing biofuels. Additional water will be required to grow more crops to serve as the raw materials for biofuels and to process the raw materials into biofuels. This report provides information about an opportunity to reuse an abundant water source -- treated municipal wastewater, also known as 'reclaimed water' -- for cooling and process water in electric generating facilities. The report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Innovations for Existing Plants research program (Feeley 2005). This program initiated an energy-water research effort in 2003 that includes the availability and use of 'nontraditional sources' of water for use at power plants. This report represents a unique reference for information on the use of reclaimed water for power plant cooling. In particular, the database of reclaimed water user facilities described in Chapter 2 is the first comprehensive national effort to identify and

Power generating system and method utilizing hydropyrolysis

DOEpatents

Tolman, R.

1986-12-30

A vapor transmission cycle is described which burns a slurry of coal and water with some of the air from the gas turbine compressor, cools and cleans the resulting low-Btu fuel gas, burns the clean fuel gas with the remaining air from the compressor, and extracts the available energy in the gas turbine. The cycle lends itself to combined-cycle cogeneration for the production of steam, absorption cooling, and electric power.

A thermosyphon heat pipe cooler for high power LEDs cooling

NASA Astrophysics Data System (ADS)

Li, Ji; Tian, Wenkai; Lv, Lucang

2016-08-01

Light emitting diode (LED) cooling is facing the challenge of high heat flux more seriously with the increase of input power and diode density. The proposed unique thermosyphon heat pipe heat sink is particularly suitable for cooling of high power density LED chips and other electronics, which has a heat dissipation potential of up to 280 W within an area of 20 mm × 22 mm (>60 W/cm2) under natural air convection. Meanwhile, a thorough visualization investigation was carried out to explore the two phase flow characteristics in the proposed thermosyphon heat pipe. Implementing this novel thermosyphon heat pipe heat sink in the cooling of a commercial 100 W LED integrated chip, a very low apparent thermal resistance of 0.34 K/W was obtained under natural air convection with the aid of the enhanced boiling heat transfer at the evaporation side and the enhanced natural air convection at the condensation side.

Interfacial condensation induced by sub-cooled liquid jet

NASA Astrophysics Data System (ADS)

Rame, Enrique; Balasubramaniam, R.

2016-11-01

When a sub-cooled liquid jet impinges on the free surface between a liquid and its vapor, vapor will condense at a rate dependent on the sub-cooling, the jet strength and fluid properties. In 1966 and during the examination of a different type of condensation flow, Shekriladeze found an approximate result, valid at large condensation rates, that decouples the flow in the liquid phase from that of the vapor, without putting it in the context of a formal asymptotic approximation. In this talk we will develop an asymptotic approximation that contains Shekriladze's result, and extend the calculations to the case when a non-condensable gas is present in the vapor phase.

Closed Form Equations for the Preliminary Design of a Heat-Pipe-Cooled Leading Edge

NASA Technical Reports Server (NTRS)

Glass, David E.

1998-01-01

A set of closed form equations for the preliminary evaluation and design of a heat-pipe-cooled leading edge is presented. The set of equations can provide a leading-edge designer with a quick evaluation of the feasibility of using heat-pipe cooling. The heat pipes can be embedded in a metallic or composite structure. The maximum heat flux, total integrated heat load, and thermal properties of the structure and heat-pipe container are required input. The heat-pipe operating temperature, maximum surface temperature, heat-pipe length, and heat pipe-spacing can be estimated. Results using the design equations compared well with those from a 3-D finite element analysis for both a large and small radius leading edge.

Personal, closed-cycle cooling and protective apparatus and thermal battery therefor

DOEpatents

Klett, James W.; Klett, Lynn B.

2004-07-20

A closed-cycle apparatus for cooling a living body includes a heat pickup body or garment which permits evaporation of an evaporating fluid, transmission of the vapor to a condenser, and return of the condensate to the heat pickup body. A thermal battery cooling source is provided for removing heat from the condenser. The apparatus requires no external power and provides a cooling system for soldiers, race car drivers, police officers, firefighters, bomb squad technicians, and other personnel who may utilize protective clothing to work in hostile environments. An additional shield layer may simultaneously provide protection from discomfort, illness or injury due to harmful atmospheres, projectiles, edged weapons, impacts, explosions, heat, poisons, microbes, corrosive agents, or radiation, while simultaneously removing body heat from the wearer.

Power converter having improved fluid cooling

DOEpatents

Meyer, Andreas A.; Radosevich, Lawrence D.; Beihoff, Bruce C.; Kehl, Dennis L.; Kannenberg, Daniel G.

2007-03-06

A thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support, which may be controlled in a closed-loop manner. Interfacing between circuits, circuit mounting structure, and the support provide for greatly enhanced cooling. The support may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

Simulation of cooling efficiency via miniaturised channels in multilayer LTCC for power electronics

NASA Astrophysics Data System (ADS)

Pietrikova, Alena; Girasek, Tomas; Lukacs, Peter; Welker, Tilo; Müller, Jens

2017-03-01

The aim of this paper is detailed investigation of thermal resistance, flow analysis and distribution of coolant as well as thermal distribution inside multilayer LTCC substrates with embedded channels for power electronic devices by simulation software. For this reason four various structures of internal channels in the multilayer LTCC substrates were designed and simulated. The impact of the volume flow, structures of channels, and power loss of chip was simulated, calculated and analyzed by using the simulation software Mentor Graphics FloEFDTM. The structure, size and location of channels have the significant impact on thermal resistance, pressure of coolant as well as the effectivity of cooling power components (chips) that can be placed on the top of LTCC substrate. The main contribution of this paper is thermal analyze, optimization and impact of 4 various cooling channels embedded in LTCC multilayer structure. Paper investigate, the effect of volume flow in cooling channels for achieving the least thermal resistance of LTCC substrate that is loaded by power thermal chips. Paper shows on the impact of the first chips thermal load on the second chip as well as. This possible new technology could ensure in the case of practical realization effective cooling and increasing reliability of high power modules.

14 CFR 23.1047 - Cooling test procedures for reciprocating engine powered airplanes.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Cooling test procedures for reciprocating engine powered airplanes. 23.1047 Section 23.1047 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION.... 23-51, 61 FR 5137, Feb. 9, 1996] Liquid Cooling ...

14 CFR 23.1047 - Cooling test procedures for reciprocating engine powered airplanes.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Cooling test procedures for reciprocating engine powered airplanes. 23.1047 Section 23.1047 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION.... 23-51, 61 FR 5137, Feb. 9, 1996] Liquid Cooling ...

14 CFR 23.1047 - Cooling test procedures for reciprocating engine powered airplanes.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling test procedures for reciprocating engine powered airplanes. 23.1047 Section 23.1047 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION.... 23-51, 61 FR 5137, Feb. 9, 1996] Liquid Cooling ...

14 CFR 23.1047 - Cooling test procedures for reciprocating engine powered airplanes.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Cooling test procedures for reciprocating engine powered airplanes. 23.1047 Section 23.1047 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION.... 23-51, 61 FR 5137, Feb. 9, 1996] Liquid Cooling ...

14 CFR 23.1047 - Cooling test procedures for reciprocating engine powered airplanes.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Cooling test procedures for reciprocating engine powered airplanes. 23.1047 Section 23.1047 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION.... 23-51, 61 FR 5137, Feb. 9, 1996] Liquid Cooling ...

Ultra-low power, Zeno effect based optical modulation in a degenerate V-system with a tapered nano fiber in atomic vapor.

PubMed

Salit, K; Salit, M; Krishnamurthy, Subramanian; Wang, Y; Kumar, P; Shahriar, M S

2011-11-07

We demonstrate an ultra-low light level optical modulator using a tapered nano fiber embedded in a hot rubidium vapor. The control and signal beams are co-propagating but orthogonally polarized, leading to a degenerate V-system involving coherent superpositions of Zeeman sublevels. The modulation is due primarily to the quantum Zeno effect for the signal beam induced by the control beam. For a control power of 40 nW and a signal power of 100 pW, we observe near 100% modulation. The ultra-low power level needed for the modulation is due to a combination of the Zeno effect and the extreme field localization in the evanescent field around the taper.

Cooling by conversion of para to ortho-hydrogen

NASA Technical Reports Server (NTRS)

Sherman, A. (Inventor)

1983-01-01

The cooling capacity of a solid hydrogen cooling system is significantly increased by exposing vapor created during evaporation of a solid hydrogen mass to a catalyst and thereby accelerating the endothermic para-to-ortho transition of the vapor to equilibrium hydrogen. Catalyst such as nickel, copper, iron or metal hydride gels of films in a low pressure drop catalytic reactor are suitable for accelerating the endothermic para-to-ortho conversion.

Numerical modelling of series-parallel cooling systems in power plant

NASA Astrophysics Data System (ADS)

Regucki, Paweł; Lewkowicz, Marek; Kucięba, Małgorzata

2017-11-01

The paper presents a mathematical model allowing one to study series-parallel hydraulic systems like, e.g., the cooling system of a power boiler's auxiliary devices or a closed cooling system including condensers and cooling towers. The analytical approach is based on a set of non-linear algebraic equations solved using numerical techniques. As a result of the iterative process, a set of volumetric flow rates of water through all the branches of the investigated hydraulic system is obtained. The calculations indicate the influence of changes in the pipeline's geometrical parameters on the total cooling water flow rate in the analysed installation. Such an approach makes it possible to analyse different variants of the modernization of the studied systems, as well as allowing for the indication of its critical elements. Basing on these results, an investor can choose the optimal variant of the reconstruction of the installation from the economic point of view. As examples of such a calculation, two hydraulic installations are described. One is a boiler auxiliary cooling installation including two screw ash coolers. The other is a closed cooling system consisting of cooling towers and condensers.

High power cable with internal water cooling 400 kV

NASA Astrophysics Data System (ADS)

Rasquin, W.; Harjes, B.

1982-08-01

Due to the concentration of electricity production in large power plants, the need of higher power transmissions, and the protection of environment, developement of a 400 kV water cooled cable in the power range of 1 to 5 GVA was undertaken. The fabrication and testing of equipment, engineering of cable components, fabrication of a test cable, development of cable terminal laboratory, testing of test cable, field testing of test cable, fabrication of industrial cable laboratory, testing of industrial cable, field testing of industrial cable, and system analysis for optimization were prepared. The field testing was impossible to realize. However, it is proved that a cable consisting of an internal stainless steel water cooled tube, covered by stranded copper profiles, insulated with heavy high quality paper, and protected by an aluminum cover can be produced, withstand tests accordingly to IEC/VDE recommendations, and is able to fulfill all exploitation conditions.

Induction heating pure vapor source of high temperature melting point materials on electron cyclotron resonance ion source.

PubMed

Kutsumi, Osamu; Kato, Yushi; Matsui, Yuuki; Kitagawa, Atsushi; Muramatsu, Masayuki; Uchida, Takashi; Yoshida, Yoshikazu; Sato, Fuminobu; Iida, Toshiyuki

2010-02-01

Multicharged ions that are needed are produced from solid pure material with high melting point in an electron cyclotron resonance ion source. We develop an evaporator by using induction heating (IH) with multilayer induction coil, which is made from bare molybdenum or tungsten wire without water cooling and surrounding the pure vaporized material. We optimize the shapes of induction coil and vaporized materials and operation of rf power supply. We conduct experiment to investigate the reproducibility and stability in the operation and heating efficiency. IH evaporator produces pure material vapor because materials directly heated by eddy currents have no contact with insulated materials, which are usually impurity gas sources. The power and the frequency of the induction currents range from 100 to 900 W and from 48 to 23 kHz, respectively. The working pressure is about 10(-4)-10(-3) Pa. We measure the temperature of the vaporized materials with different shapes, and compare them with the result of modeling. We estimate the efficiency of the IH vapor source. We are aiming at the evaporator's higher melting point material than that of iron.

Induction heating pure vapor source of high temperature melting point materials on electron cyclotron resonance ion sourcea)

NASA Astrophysics Data System (ADS)

Kutsumi, Osamu; Kato, Yushi; Matsui, Yuuki; Kitagawa, Atsushi; Muramatsu, Masayuki; Uchida, Takashi; Yoshida, Yoshikazu; Sato, Fuminobu; Iida, Toshiyuki

2010-02-01

Multicharged ions that are needed are produced from solid pure material with high melting point in an electron cyclotron resonance ion source. We develop an evaporator by using induction heating (IH) with multilayer induction coil, which is made from bare molybdenum or tungsten wire without water cooling and surrounding the pure vaporized material. We optimize the shapes of induction coil and vaporized materials and operation of rf power supply. We conduct experiment to investigate the reproducibility and stability in the operation and heating efficiency. IH evaporator produces pure material vapor because materials directly heated by eddy currents have no contact with insulated materials, which are usually impurity gas sources. The power and the frequency of the induction currents range from 100to900W and from 48to23kHz, respectively. The working pressure is about 10-4-10-3Pa. We measure the temperature of the vaporized materials with different shapes, and compare them with the result of modeling. We estimate the efficiency of the IH vapor source. We are aiming at the evaporator's higher melting point material than that of iron.

Implications of Transitioning from De Facto to Engineered Water Reuse for Power Plant Cooling.

PubMed

Barker, Zachary A; Stillwell, Ashlynn S

2016-05-17

Thermoelectric power plants demand large quantities of cooling water, and can use alternative sources like treated wastewater (reclaimed water); however, such alternatives generate many uncertainties. De facto water reuse, or the incidental presence of wastewater effluent in a water source, is common at power plants, representing baseline conditions. In many cases, power plants would retrofit open-loop systems to cooling towers to use reclaimed water. To evaluate the feasibility of reclaimed water use, we compared hydrologic and economic conditions at power plants under three scenarios: quantified de facto reuse, de facto reuse with cooling tower retrofits, and modeled engineered reuse conditions. We created a genetic algorithm to estimate costs and model optimal conditions. To assess power plant performance, we evaluated reliability metrics for thermal variances and generation capacity loss as a function of water temperature. Applying our analysis to the greater Chicago area, we observed high de facto reuse for some power plants and substantial costs for retrofitting to use reclaimed water. Conversely, the gains in reliability and performance through engineered reuse with cooling towers outweighed the energy investment in reclaimed water pumping. Our analysis yields quantitative results of reclaimed water feasibility and can inform sustainable management of water and energy.

User's manual for the BNW-I optimization code for dry-cooled power plants. Volume III. [PLCIRI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braun, D.J.; Daniel, D.J.; De Mier, W.V.

1977-01-01

This appendix to User's Manual for the BNW-1 Optimization Code for Dry-Cooled Power Plants provides a listing of the BNW-I optimization code for determining, for a particular size power plant, the optimum dry cooling tower design using a plastic tube cooling surface and circular tower arrangement of the tube bundles. (LCL)

Wetland Water Cooling Partnership: The Use of Constructed Wetlands to Enhance Thermoelectric Power Plant Cooling and Mitigate the Demand of Surface Water Use

DOE Office of Scientific and Technical Information (OSTI.GOV)

Apfelbaum, Steven L.; Duvall, Kenneth W.; Nelson, Theresa M.

Through the Phase I study segment of contract #DE-NT0006644 with the U.S. Department of Energy’s National Energy Technology Laboratory, Applied Ecological Services, Inc. and Sterling Energy Services, LLC (the AES/SES Team) explored the use of constructed wetlands to help address stresses on surface water and groundwater resources from thermoelectric power plant cooling and makeup water requirements. The project objectives were crafted to explore and develop implementable water conservation and cooling strategies using constructed wetlands (not existing, naturally occurring wetlands), with the goal of determining if this strategy has the potential to reduce surface water and groundwater withdrawals of thermoelectric powermore » plants throughout the country. Our team’s exploratory work has documented what appears to be a significant and practical potential for augmenting power plant cooling water resources for makeup supply at many, but not all, thermoelectric power plant sites. The intent is to help alleviate stress on existing surface water and groundwater resources through harvesting, storing, polishing and beneficially re-using critical water resources. Through literature review, development of conceptual created wetland plans, and STELLA-based modeling, the AES/SES team has developed heat and water balances for conventional thermoelectric power plants to evaluate wetland size requirements, water use, and comparative cooling technology costs. The ecological literature on organism tolerances to heated waters was used to understand the range of ecological outcomes achievable in created wetlands. This study suggests that wetlands and water harvesting can provide a practical and cost-effective strategy to augment cooling waters for thermoelectric power plants in many geographic settings of the United States, particularly east of the 100th meridian, and in coastal and riverine locations. The study concluded that constructed wetlands can have significant

Integrated three-dimensional module heat exchanger for power electronics cooling

DOEpatents

Bennion, Kevin; Lustbader, Jason

2013-09-24

Embodiments discussed herein are directed to a power semiconductor packaging that removes heat from a semiconductor package through one or more cooling zones that are located in a laterally oriented position with respect to the semiconductor package. Additional embodiments are directed to circuit elements that are constructed from one or more modular power semiconductor packages.

Structure and Dynamical Influence of Water Vapor in the Lower Tropical Troposphere

NASA Astrophysics Data System (ADS)

Stevens, Bjorn; Brogniez, Hélène; Kiemle, Christoph; Lacour, Jean-Lionel; Crevoisier, Cyril; Kiliani, Johannes

In situ, airborne and satellite measurements are used to characterize the structure of water vapor in the lower tropical troposphere—below the height, z *, of the triple-point isotherm, T *. The measurements are evaluated in light of understanding of how lowertropospheric water vapor influences clouds, convection and circulation, through both radiative and thermodynamic effects. Lower-tropospheric water vapor, which concentrates in the first few kilometers above the boundary layer, controls the radiative cooling profile of the boundary layer and lower troposphere. Elevated moist layers originating from a preferred level of convective detrainment induce a profile of radiative cooling that drives circulations which reinforce such features. A theory for this preferred level of cumulus termination is advanced, whereby the difference between T * and the temperature at which primary ice forms gives a `first-mover advantage' to glaciating cumulus convection, thereby concentrating the regions of the deepest convection and leading to more clouds and moisture near the triple point. A preferred level of convective detrainment near T * implies relative humidity reversals below z * which are difficult to identify using retrievals from satellite-borne microwave and infrared sounders. Isotopologues retrievals provide a hint of such features and their ability to constrain the structure of the vertical humidity profile merits further study. Nonetheless, it will likely remain challenging to resolve dynamically important aspects of the vertical structure of water vapor from space using only passive sensors.

Structure and Dynamical Influence of Water Vapor in the Lower Tropical Troposphere

NASA Astrophysics Data System (ADS)

Stevens, Bjorn; Brogniez, Hélène; Kiemle, Christoph; Lacour, Jean-Lionel; Crevoisier, Cyril; Kiliani, Johannes

2017-11-01

In situ, airborne and satellite measurements are used to characterize the structure of water vapor in the lower tropical troposphere—below the height, z_*, of the triple-point isotherm, T_*. The measurements are evaluated in light of understanding of how lower-tropospheric water vapor influences clouds, convection and circulation, through both radiative and thermodynamic effects. Lower-tropospheric water vapor, which concentrates in the first few kilometers above the boundary layer, controls the radiative cooling profile of the boundary layer and lower troposphere. Elevated moist layers originating from a preferred level of convective detrainment induce a profile of radiative cooling that drives circulations which reinforce such features. A theory for this preferred level of cumulus termination is advanced, whereby the difference between T_* and the temperature at which primary ice forms gives a `first-mover advantage' to glaciating cumulus convection, thereby concentrating the regions of the deepest convection and leading to more clouds and moisture near the triple point. A preferred level of convective detrainment near T_* implies relative humidity reversals below z* which are difficult to identify using retrievals from satellite-borne microwave and infrared sounders. Isotopologues retrievals provide a hint of such features and their ability to constrain the structure of the vertical humidity profile merits further study. Nonetheless, it will likely remain challenging to resolve dynamically important aspects of the vertical structure of water vapor from space using only passive sensors.

Optimal Self-Tuning PID Controller Based on Low Power Consumption for a Server Fan Cooling System.

PubMed

Lee, Chengming; Chen, Rongshun

2015-05-20

Recently, saving the cooling power in servers by controlling the fan speed has attracted considerable attention because of the increasing demand for high-density servers. This paper presents an optimal self-tuning proportional-integral-derivative (PID) controller, combining a PID neural network (PIDNN) with fan-power-based optimization in the transient-state temperature response in the time domain, for a server fan cooling system. Because the thermal model of the cooling system is nonlinear and complex, a server mockup system simulating a 1U rack server was constructed and a fan power model was created using a third-order nonlinear curve fit to determine the cooling power consumption by the fan speed control. PIDNN with a time domain criterion is used to tune all online and optimized PID gains. The proposed controller was validated through experiments of step response when the server operated from the low to high power state. The results show that up to 14% of a server's fan cooling power can be saved if the fan control permits a slight temperature response overshoot in the electronic components, which may provide a time-saving strategy for tuning the PID controller to control the server fan speed during low fan power consumption.

The development of a solar-powered residential heating and cooling system

NASA Technical Reports Server (NTRS)

1974-01-01

Efforts to demonstrate the engineering feasibility of utilizing solar power for residential heating and cooling are described. These efforts were concentrated on the analysis, design, and test of a full-scale demonstration system which is currently under construction at the National Aeronautics and Space Administration, Marshall Space Flight Center, Huntsville, Alabama. The basic solar heating and cooling system under development utilizes a flat plate solar energy collector, a large water tank for thermal energy storage, heat exchangers for space heating and water heating, and an absorption cycle air conditioner for space cooling.

Data center cooling method

DOEpatents

Chainer, Timothy J.; Dang, Hien P.; Parida, Pritish R.; Schultz, Mark D.; Sharma, Arun

2015-08-11

A method aspect for removing heat from a data center may use liquid coolant cooled without vapor compression refrigeration on a liquid cooled information technology equipment rack. The method may also include regulating liquid coolant flow to the data center through a range of liquid coolant flow values with a controller-apparatus based upon information technology equipment temperature threshold of the data center.

Venus Surface Power and Cooling System Design

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; Mellott, Kenneth D.

2004-01-01

A radioisotope power and cooling system is designed to provide electrical power for the a probe operating on the surface of Venus. Most foreseeable electronics devices and sensors simply cannot operate at the 450 C ambient surface temperature of Venus. Because the mission duration is substantially long and the use of thermal mass to maintain an operable temperature range is likely impractical, some type of active refrigeration may be required to keep certain components at a temperature below ambient. The fundamental cooling requirements are comprised of the cold sink temperature, the hot sink temperature, and the amount of heat to be removed. In this instance, it is anticipated that electronics would have a nominal operating temperature of 300 C. Due to the highly thermal convective nature of the high-density atmosphere, the hot sink temperature was assumed to be 50 C, which provided a 500 C temperature of the cooler's heat rejecter to the ambient atmosphere. The majority of the heat load on the cooler is from the high temperature ambient surface environment on Venus. Assuming 5 cm radial thickness of ceramic blanket insulation, the ambient heat load was estimated at approximately 77 watts. With an estimated quantity of 10 watts of heat generation from electronics and sensors, and to accommodate some level of uncertainty, the total heat load requirement was rounded up to an even 100 watts. For the radioisotope Stirling power converter configuration designed, the Sage model predicts a thermodynamic power output capacity of 478.1 watts, which slightly exceeds the required 469.1 watts. The hot sink temperature is 1200 C, and the cold sink temperature is 500 C. The required heat input is 1740 watts. This gives a thermodynamic efficiency of 27.48 %. The maximum theoretically obtainable efficiency is 47.52 %. It is estimated that the mechanical efficiency of the power converter design is on the order of 85 %, based on experimental measurements taken from 500 watt power

Cooling circuit for steam and air-cooled turbine nozzle stage

DOEpatents

Itzel, Gary Michael; Yu, Yufeng

2002-01-01

The turbine vane segment includes inner and outer walls with a vane extending therebetween. The vane includes leading and trailing edge cavities and intermediate cavities. An impingement plate is spaced from the outer wall to impingement-cool the outer wall. Post-impingement cooling air flows through holes in the outer wall to form a thin air-cooling film along the outer wall. Cooling air is supplied an insert sleeve with openings in the leading edge cavity for impingement-cooling the leading edge. Holes through the leading edge afford thin-film cooling about the leading edge. Cooling air is provided the trailing edge cavity and passes through holes in the side walls of the vane for thin-film cooling of the trailing edge. Steam flows through a pair of intermediate cavities for impingement-cooling of the side walls. Post-impingement steam flows to the inner wall for impingement-cooling of the inner wall and returns the post-impingement cooling steam through inserts in other intermediate cavities for impingement-cooling the side walls of the vane.

Jumping-droplet electronics hot-spot cooling

DOE PAGES

Oh, Junho; Birbarah, Patrick; Foulkes, Thomas; ...

2017-03-20

Demand for enhanced cooling technologies within various commercial and consumer applications has increased in recent decades due to electronic devices becoming more energy dense. This study demonstrates jumping-droplet based electric-field-enhanced (EFE) condensation as a potential method to achieve active hot spot cooling in electronic devices. To test the viability of EFE condensation, we developed an experimental setup to remove heat via droplet evaporation from single and multiple high power gallium nitride (GaN) transistors acting as local hot spots (4.6 mm x 2.6 mm). An externally powered circuit was developed to direct jumping droplets from a copper oxide (CuO) nanostructured superhydrophobicmore » surface to the transistor hot spots by applying electric fields between the condensing surface and the transistor. Heat transfer measurements were performed in ambient air (22-25°C air temperature, 20-45% relative humidity) to determine the effect of gap spacing (2-4 mm), electric field (50-250 V/cm), and heat flux (demonstrated to 13 W/cm 2). EFE condensation was shown to enhance the heat transfer from the local hot spot by ≈ 200% compared to cooling without jumping and by 20% compared to non-EFE jumping. Dynamic switching of the electric field for a two-GaN system reveals the potential for active cooling of mobile hot spots. The opportunity for further cooling enhancement by the removal of non-condensable gases promises hot spot heat dissipation rates approaching 120 W/cm 2. Finally, this work provides a framework for the development of active jumping droplet based vapor chambers and heat pipes capable of spatial and temporal thermal dissipation control.« less

Jumping-droplet electronics hot-spot cooling

NASA Astrophysics Data System (ADS)

Oh, Junho; Birbarah, Patrick; Foulkes, Thomas; Yin, Sabrina L.; Rentauskas, Michelle; Neely, Jason; Pilawa-Podgurski, Robert C. N.; Miljkovic, Nenad

2017-03-01

Demand for enhanced cooling technologies within various commercial and consumer applications has increased in recent decades due to electronic devices becoming more energy dense. This study demonstrates jumping-droplet based electric-field-enhanced (EFE) condensation as a potential method to achieve active hot spot cooling in electronic devices. To test the viability of EFE condensation, we developed an experimental setup to remove heat via droplet evaporation from single and multiple high power gallium nitride (GaN) transistors acting as local hot spots (4.6 mm × 2.6 mm). An externally powered circuit was developed to direct jumping droplets from a copper oxide (CuO) nanostructured superhydrophobic surface to the transistor hot spots by applying electric fields between the condensing surface and the transistor. Heat transfer measurements were performed in ambient air (22-25 °C air temperature, 20%-45% relative humidity) to determine the effect of gap spacing (2-4 mm), electric field (50-250 V/cm) and applied heat flux (demonstrated to 13 W/cm2). EFE condensation was shown to enhance the heat transfer from the local hot spot by ≈200% compared to cooling without jumping and by 20% compared to non-EFE jumping. Dynamic switching of the electric field for a two-GaN system reveals the potential for active cooling of mobile hot spots. The opportunity for further cooling enhancement by the removal of non-condensable gases promises hot spot heat dissipation rates approaching 120 W/cm2. This work provides a framework for the development of active jumping droplet based vapor chambers and heat pipes capable of spatial and temporal thermal dissipation control.

Jumping-droplet electronics hot-spot cooling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh, Junho; Birbarah, Patrick; Foulkes, Thomas

Demand for enhanced cooling technologies within various commercial and consumer applications has increased in recent decades due to electronic devices becoming more energy dense. This study demonstrates jumping-droplet based electric-field-enhanced (EFE) condensation as a potential method to achieve active hot spot cooling in electronic devices. To test the viability of EFE condensation, we developed an experimental setup to remove heat via droplet evaporation from single and multiple high power gallium nitride (GaN) transistors acting as local hot spots (4.6 mm x 2.6 mm). An externally powered circuit was developed to direct jumping droplets from a copper oxide (CuO) nanostructured superhydrophobicmore » surface to the transistor hot spots by applying electric fields between the condensing surface and the transistor. Heat transfer measurements were performed in ambient air (22-25°C air temperature, 20-45% relative humidity) to determine the effect of gap spacing (2-4 mm), electric field (50-250 V/cm), and heat flux (demonstrated to 13 W/cm 2). EFE condensation was shown to enhance the heat transfer from the local hot spot by ≈ 200% compared to cooling without jumping and by 20% compared to non-EFE jumping. Dynamic switching of the electric field for a two-GaN system reveals the potential for active cooling of mobile hot spots. The opportunity for further cooling enhancement by the removal of non-condensable gases promises hot spot heat dissipation rates approaching 120 W/cm 2. Finally, this work provides a framework for the development of active jumping droplet based vapor chambers and heat pipes capable of spatial and temporal thermal dissipation control.« less

Development of a wet vapor homogeneous liquid metal MHD power system

NASA Astrophysics Data System (ADS)

1989-04-01

During the period covered by this report (October 1988 to March 1989), the following work was done: the mixing stream condensation process was analyzed, and a theoretical model for simulating this process was modified. A parametric study is being conducted at the present time; the separation processes were analyzed; and the experimental system was specified and its design is at present in an advanced stage. The mixing stream condensation process was analyzed. For the parameters defined in the SOW of this project the process was found to be a mist flow direct contact condensation, where the hot gas mixture consisting of inert gas and vapor is the continuous phase, and the subcooled liquid on which the vapor is condensed if the droplets dispersed phase. Two possibilities of creating the mist flow were considered. The first, injecting the cold Liquid Metal (LM) into the Mixing Streams Condenser (MSC) entrance as a jet and breaking it into LM fragments and the fragments into droplets by momentum transfer breakup mechanism. The second, atomizing the cooled LM stream into little droplets (approximately 100 micrometers in diameter) and accelerating them by the gas. The second possibility was preferred due to its much higher heat and mass transfer surface and coefficients relative to the first one.

Resource-Saving Cleaning Technologies for Power Plant Waste-Water Cooling Ponds

NASA Astrophysics Data System (ADS)

Zakonnova, Lyudmila; Nikishkin, Igor; Rostovzev, Alexandr

2017-11-01

One of the frequently encountered problems of power plant small cooling ponds is rapid eutrophication and related intensified development of phytoplankton ("hyperflow") and overgrowing of ponds by higher aquatic vegetation. As a result of hyper-flowering, an enormous amount of detritus settles on the condenser tubes, reducing the efficiency of the power plant operation. The development of higher aquatic vegetation contributes to the appearing of the shoals. As a result the volume, area and other characteristics of the cooling ponds are getting changed. The article describes the environmental problems of small manmade ponds of power plants and coal mines in mining regions. Two approaches to the problem of eutrophication are considered: technological and ecological. The negative effects of herbicides application to aquatic organisms are experimentally proved. An ecological approach to solving the problem by fish-land reclamation method is shown.

Solar heat collector-generator for cooling purposes

NASA Astrophysics Data System (ADS)

Abdullah, K.

1982-01-01

The performance of an experimental LiBr-H2O solar collector powered absorption cooling system is described. A numerical model was developed of the energy, mass, and momentum balances across the heat-exchange loop to obtain the refrigerant vapor generation rate. The mechanism works by the thermosiphon principle, which eliminates mechanical devices from the loop. All leaks were fixed before measurements began with a test apparatus comprising a pyrex tube 1.87 m long with a 2.7 i.d. The refrigerant flow rate was monitored, along with temperature changes in the fluid and across the tube. Bubble initiation was observed from the free surface extending downward in the tube. Reynolds numbers varied from 6-43 in the liquid phase and 81-204 in the vapor phase. A formulation was made for the low-velocity two-phase flow and good agreement was demonstrated with the simulation.

Thermoacoustic Duplex Technology for Cooling and Powering a Venus Lander

NASA Astrophysics Data System (ADS)

Walker, A. R.; Haberbusch, M. S.; Sasson, J.

2015-04-01

A Thermoacoustic Stirling Heat Engine (TASHE) is directly coupled to a Pulse Tube Refrigerator (PTR) in a duplex configuration, providing simultaneous cooling and electrical power, thereby suiting the needs of a long-lived Venus lander.

Comparative analysis of cooling systems for energy equipment of combined heat and power plants and nuclear power plants

NASA Astrophysics Data System (ADS)

Reutov, B. F.; Lazarev, M. V.; Ermakova, S. V.; Zisman, S. L.; Kaplanovich, L. S.; Svetushkov, V. V.

2016-07-01

In the 20th century, the thermal power engineering in this country was oriented toward oncethrough cooling systems. More than 50% of the CHPP and NPP capacities with once-through cooling systems put into operation before the 1990s were large-scale water consumers but with minimum irretrievable water consumption. In 1995, the Water Code of the Russian Federation was adopted in which restrictions on application of once-through cooling systems for newly designed combined heat and power plants (CHPPs) were introduced for the first time. A ban on application of once-through systems was imposed by the current Water Code of the Russian Federation (Federal law no. 74-FZ, Art. 60 Cl. 4) not only for new CHPPs but also for those to be modified. Clause 4 of Article 60 of the Water Code of the Russian Federation contravenes law no. 7-FZ "On Protection of the Environment" that has priority significance, since the water environment is only part of the natural environment and those articles of the Water Code of the Russian Federation that are related directly to electric power engineering, viz., Articles 46 and 62. In recent decades, the search for means to increase revenue charges and the economic pressure on the thermal power industry caused introduction by law of charges for use of water by cooling systems irrespective of the latter's impact on the water quality of the source, the environment, the economic efficiency of the power production, and the living conditions of the people. The long-range annual increase in the water use charges forces the power generating companies to switch transfer once-through service water supply installations to recirculating water supply systems and once-through-recirculating systems with multiple reuse of warm water, which drastically reduces the technical, economic, and ecological characteristic of the power plant operation and also results in increasing power rates for the population. This work comprehensively substantiates the demands of

The lithium vapor box divertor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldston, R. J.; Myers, R.; Schwartz, J.

It has long been recognized that volumetric dissipation of the plasma heat flux from a fusion power system is preferable to its localized impingement on a material surface. Volumetric dissipation mitigates both the anticipated very high heat flux and intense particle-induced damage due to sputtering. Our recent projections to a tokamak demonstration power plant suggest an immense upstream parallel heat flux, of order 20 GW m -2, implying that fully detached operation may be a requirement for the success of fusion power. Building on pioneering work on the use of lithium by Nagayama et al and by Ono et almore » as well as earlier work on the gas box divertor by Watkins and Rebut, we present here a concept for a lithium vapor box divertor, in which lithium vapor extracts momentum and energy from a fusion-power-plant divertor plasma, using fully volumetric processes. Furthermore, at the high powers and pressures that are projected this requires a high density of lithium vapor, which must be isolated from the main plasma in order to avoid lithium build-up on the chamber walls or in the plasma. Isolation is achieved through a powerful multi-box differential pumping scheme available only for condensable vapors. The preliminary box-wise calculations are encouraging, but much more work is required in order to demonstrate the practical viability of this scheme, taking into account at least 2D plasma and vapor flows within and between the vapor boxes and out of the vapor boxes to the main plasma.« less

The lithium vapor box divertor

NASA Astrophysics Data System (ADS)

Goldston, R. J.; Myers, R.; Schwartz, J.

2016-02-01

It has long been recognized that volumetric dissipation of the plasma heat flux from a fusion power system is preferable to its localized impingement on a material surface. Volumetric dissipation mitigates both the anticipated very high heat flux and intense particle-induced damage due to sputtering. Recent projections to a tokamak demonstration power plant suggest an immense upstream parallel heat flux, of order 20 GW m-2, implying that fully detached operation may be a requirement for the success of fusion power. Building on pioneering work on the use of lithium by Nagayama et al and by Ono et al as well as earlier work on the gas box divertor by Watkins and Rebut, we present here a concept for a lithium vapor box divertor, in which lithium vapor extracts momentum and energy from a fusion-power-plant divertor plasma, using fully volumetric processes. At the high powers and pressures that are projected this requires a high density of lithium vapor, which must be isolated from the main plasma in order to avoid lithium build-up on the chamber walls or in the plasma. Isolation is achieved through a powerful multi-box differential pumping scheme available only for condensable vapors. The preliminary box-wise calculations are encouraging, but much more work is required to demonstrate the practical viability of this scheme, taking into account at least 2D plasma and vapor flows within and between the vapor boxes and out of the vapor boxes to the main plasma.

The lithium vapor box divertor

DOE PAGES

Goldston, R. J.; Myers, R.; Schwartz, J.

2016-01-13

It has long been recognized that volumetric dissipation of the plasma heat flux from a fusion power system is preferable to its localized impingement on a material surface. Volumetric dissipation mitigates both the anticipated very high heat flux and intense particle-induced damage due to sputtering. Our recent projections to a tokamak demonstration power plant suggest an immense upstream parallel heat flux, of order 20 GW m -2, implying that fully detached operation may be a requirement for the success of fusion power. Building on pioneering work on the use of lithium by Nagayama et al and by Ono et almore » as well as earlier work on the gas box divertor by Watkins and Rebut, we present here a concept for a lithium vapor box divertor, in which lithium vapor extracts momentum and energy from a fusion-power-plant divertor plasma, using fully volumetric processes. Furthermore, at the high powers and pressures that are projected this requires a high density of lithium vapor, which must be isolated from the main plasma in order to avoid lithium build-up on the chamber walls or in the plasma. Isolation is achieved through a powerful multi-box differential pumping scheme available only for condensable vapors. The preliminary box-wise calculations are encouraging, but much more work is required in order to demonstrate the practical viability of this scheme, taking into account at least 2D plasma and vapor flows within and between the vapor boxes and out of the vapor boxes to the main plasma.« less

Dynamics of vapor emissions at wire explosion thresholda)

NASA Astrophysics Data System (ADS)

Belony, Paul A.; Kim, Yong W.

2010-10-01

X-pinch plasmas have been actively studied in the recent years. Numerical simulation of the ramp-up of metallic vapor emissions from wire specimens shows that under impulsive Ohmic heating the wire core invariably reaches a supercritical state before explosion. The heating rate depends sensitively on the local wire resistance, leading to highly variable vapor emission flux along the wire. To examine the vapor emission process, we have visualized nickel wire explosions by means of shock formation in air. In a single explosion as captured by shadowgraphy, there usually appear several shocks with spherical or cylindrical wave front originating from different parts of the wire. Growth of various shock fronts in time is well characterized by a power-law scaling in one form or another. Continuum emission spectra are obtained and calibrated to measure temperature near the explosion threshold. Shock front structures and vapor plume temperature are examined.

Air-Cooled Heat Exchanger for High-Temperature Power Electronics: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waye, S. K.; Lustbader, J.; Musselman, M.

2015-05-06

This work demonstrates a direct air-cooled heat exchanger strategy for high-temperature power electronic devices with an application specific to automotive traction drive inverters. We present experimental heat dissipation and system pressure curves versus flow rate for baseline and optimized sub-module assemblies containing two ceramic resistance heaters that provide device heat fluxes. The maximum allowable junction temperature was set to 175 deg.C. Results were extrapolated to the inverter scale and combined with balance-of-inverter components to estimate inverter power density and specific power. The results exceeded the goal of 12 kW/L and 12 kW/kg for power density and specific power, respectively.

WATER COOLED RETORT COVER

DOEpatents

Ash, W.J.; Pozzi, J.F.

1962-05-01

A retort cover is designed for use in the production of magnesium metal by the condensation of vaporized metal on a collecting surface. The cover includes a condensing surface, insulating means adjacent to the condensing surface, ind a water-cooled means for the insulating means. The irrangement of insulation and the cooling means permits the magnesium to be condensed at a high temperature and in massive nonpyrophoric form. (AEC)

Turbine vane leading edge gas film cooling with spanwise angled coolant holes

NASA Technical Reports Server (NTRS)

Hanus, G. J.; Lecuyer, M. R.

1976-01-01

An experimental film cooling study was conducted on a 3x size model turbine vane. Injection at the leading edge was from a single row of holes angled in a spanwise direction for two configurations of holes at 18 or 35 deg to the surface. The reduction in the local Stanton number for injection at a coolant-to-mainstream density ratio of 2.18 was calculated from heat flux measurements downstream of injection. Results indicate that optimum cooling occurs near a coolant-to-mainstream velocity ratio of 0.5. Shallow injection angles appear to be most beneficial when injecting into a highly accelerated mainstream.

The study of lead vapor ionization in discharge with a hot cathode and efficiency of its deposition on the substrates applied for plasma separation method

NASA Astrophysics Data System (ADS)

Antonov, N. N.; Samokhin, A. A.; Zhabin, S. N.; Gavrikov, A. V.; Smirnov, V. P.

2016-11-01

Spent nuclear fuel plasma separation method approbation implies the use of model substances. Thus it is necessary to solve the problem of material conversion into a cold plasma flow, as well as the problem of deposition on collectors. For this purpose, we carried out a kinetic and hydrodynamic simulation of the discharge with hot cathode in the lead vapor (lead vapor was injected into the interelectrode gap). Dependencies of the ionization efficiency, electrostatic potential distribution, density distribution of ions and electrons in the discharge gap on the discharge current density and the model substance vapor concentration were obtained. The simulation results show that at discharge current density of about 3.5 A/cm2 and the lead vapor concentration of 2 × 1012 cm-3, the ionization efficiency is close to 60%. Experimental research of the discharge with a hot cathode in the lead vapor was carried out. We also carried out the research of the Pb condensation coefficients on various substrates. For experimental data analysis the numerical model based on Monte Carlo method was used. The research results show that deposition coefficients at medium temperatures of substrates near 70 °C do not drop lower than 75%.

Cool horizons lead to information loss

NASA Astrophysics Data System (ADS)

Chowdhury, Borun D.

2013-10-01

There are two evidences for information loss during black hole evaporation: (i) a pure state evolves to a mixed state and (ii) the map from the initial state to final state is non-invertible. Any proposed resolution of the information paradox must address both these issues. The firewall argument focuses only on the first and this leads to order one deviations from the Unruh vacuum for maximally entangled black holes. The nature of the argument does not extend to black holes in pure states. It was shown by Avery, Puhm and the author that requiring the initial state to final state map to be invertible mandates structure at the horizon even for pure states. The proof works if black holes can be formed in generic states and in this paper we show that this is indeed the case. We also demonstrate how models proposed by Susskind, Papadodimas et al. and Maldacena et al. end up making the initial to final state map non-invertible and thus make the horizon "cool" at the cost of unitarity.

Energy and environmental evaluation of combined cooling heating and power system

NASA Astrophysics Data System (ADS)

Bugaj, Andrzej

2017-11-01

The paper addresses issues involving problems of implementing combined cooling, heating and power (CCHP) system to industrial facility with well-defined demand profiles of cooling, heating and electricity. The application of CCHP system in this particular industrial facility is being evaluated by comparison with the reference system that consists of three conventional methods of energy supply: (a) electricity from external grid, (b) heat from gas-fired boilers and (c) cooling from vapour compression chillers run by electricity from the grid. The CCHP system scenario is based on the combined heat and power (CHP) plant with gas turbine-compressor arrangement and water/lithium bromide absorption chiller of a single-effect type. Those two scenarios are analysed in terms of annual primary energy usage as well as emissions of CO2. The results of the analysis show an extent of primary energy savings of the CCHP system in comparison with the reference system. Furthermore, the environmental impact of the CCHP usage, in the form of greenhouse gases emission reductions, compares quite favourably with the reference conventional option.

Candidate chemical systems for air cooled solar powered, absorption air conditioner design. Part I. Organic absorbent systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biermann, W. J.

1978-01-01

All the available experimental evidence suggests that the optimum ''organic'' absorbent/refrigerant combination would be a methane derivative with a single hydrogen atom with chlorine and fluorine atoms in the other sites, as refrigerant. This would be hydrogen bonded to an absorbent molecule containing the group =NC/sup -/O, with the substituent groups being such that no steric hindrance took place. Cycle analyses showed that the ratio of internal heat transfer to cooling would be large, probably impractically so in view of the high coefficient of performance needed for solar driven cooling and the additional handicap of heat rejection to the atmosphere.more » A more promising approach would be to reduce the internal heat transfer per unit of space cooling by selecting a refrigerant with a high latent heat of vaporization and selecting an absorbent with suitable properties.« less

Chemical Vapor Deposition of Turbine Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Haven, Victor E.

1999-01-01

Ceramic thermal barrier coatings extend the operating temperature range of actively cooled gas turbine components, therefore increasing thermal efficiency. Performance and lifetime of existing ceram ic coatings are limited by spallation during heating and cooling cycles. Spallation of the ceramic is a function of its microstructure, which is determined by the deposition method. This research is investigating metalorganic chemical vapor deposition (MOCVD) of yttria stabilized zirconia to improve performance and reduce costs relative to electron beam physical vapor deposition. Coatings are deposited in an induction-heated, low-pressure reactor at 10 microns per hour. The coating's composition, structure, and response to the turbine environment will be characterized.

Infrared 7.6-microm lead-salt diode laser heterodyne radiometry of water vapor in a CH4-air premixed flat flame.

PubMed

Weidmann, Damien; Courtois, Daniel

2003-02-20

We deal with the design of a diode laser heterodyne radiometer and its application in a combustion process. We present some experimental results obtained with a CH4-air premised flat flame as the optical source. The goal is to prove that heterodyne detection techniques are relevant in remote detection and diagnostics of combustion and can have important applications in both civil and military fields. To the best of our knowledge, it is the first time that this demonstration is made. The radiometer, in spite of the low-power lead-salt diode laser used as a local oscillator, enables us to record high-temperature water-vapor emission spectra in the region of 1315 cm(-1).

Testing and Optimizing a Stove-Powered Thermoelectric Generator with Fan Cooling.

PubMed

Zheng, Youqu; Hu, Jiangen; Li, Guoneng; Zhu, Lingyun; Guo, Wenwen

2018-06-07

In order to provide heat and electricity under emergency conditions in off-grid areas, a stove-powered thermoelectric generator (STEG) was designed and optimized. No battery was incorporated, ensuring it would work anytime, anywhere, as long as combustible materials were provided. The startup performance, power load feature and thermoelectric (TE) efficiency were investigated in detail. Furthermore, the heat-conducting plate thickness, cooling fan selection, heat sink dimension and TE module configuration were optimized. The heat flow method was employed to determine the TE efficiency, which was compared to the predicted data. Results showed that the STEG can supply clean-and-warm air (625 W) and electricity (8.25 W at 5 V) continuously at a temperature difference of 148 °C, and the corresponding TE efficiency was measured to be 2.31%. Optimization showed that the choice of heat-conducting plate thickness, heat sink dimensions and cooling fan were inter-dependent, and the TE module configuration affected both the startup process and the power output.

A simulation for predicting potential cooling effect on LPG-fuelled vehicles

NASA Astrophysics Data System (ADS)

Setiyo, M.; Soeparman, S.; Wahyudi, S.; Hamidi, N.

2016-03-01

Liquefied Petroleum Gas vehicles (LPG Vehicles) provide a potential cooling effect about 430 kJ/kg LPG consumption. This cooling effect is obtained from the LPG phase change from liquid to vapor in the vaporizer. In the existing system, energy to evaporate LPG is obtained from the coolant which is circulated around the vaporizer. One advantage is that the LPG (70/30 propane / butane) when expanded from 8 bar to at 1.2 bar, the temperature is less than -25 °C. These conditions provide opportunities to evaporate LPG with ambient air flow, then produce a cooling effect for cooling car's cabin. In this study, some LPG mix was investigated to determine the optimum condition. A simulation was carried out to estimate potential cooling effects of 2000 cc engine from 1000 rpm to 6000 rpm. In this case, the mass flow rate of LPG is a function of fuel consumption. The simulation result shows that the LPG (70/30 propane/butane) provide the greatest cooling effect compared with other mixtures. In conclusion, the 2000 cc engine fueled LPG at 3000 rpm provides potential cooling effect more than 1.3 kW, despite in the low engine speed (1000 rpm) only provides about 0.5 kW.

Development of beam leaded low power logic circuits

NASA Technical Reports Server (NTRS)

Smith, B. W.; Malone, F.

1972-01-01

The technologies of low power TTL and beam lead processing were merged into a single product family. This family offers the power and thermal advantages of low power(54L), while providing the additional reliability advantages of beam leads. The reduction in the power and heat levels also allows the system designer to take advantage, through beam lead, multichip assemblies, of increased package density to reduce system size and weight.

Sensitivity of F-106B Leading-Edge-Vortex Images to Flight and Vapor-Screen Parameters

NASA Technical Reports Server (NTRS)

Lamar, John E.; Johnson, Thomas D., Jr.

1988-01-01

A flight test was undertaken at NASA Langley Research Center with vapor-screen and image-enhancement techniques to obtain qualitative and quantitative information about near-field vortex flows above the wings of fighter aircraft. In particular, the effects of Reynolds and Mach numbers on the vortex system over an angle-of-attack range were sought. The relevance of these flows stems from their present and future use at many points in the flight envelope, especially during transonic maneuvers. The aircraft used in this flight program was the F-106B because it was available and had sufficient wing sweep (60 deg) to generate a significant leading-edge vortex system. The sensitivity of the visual results to vapor screen hardware and to onset flow changes is discussed.

Optimization of Cooling Water Flow Rate in Nuclear and Thermal Power Plants Based on a Mathematical Model of Cooling Systems{sup 1}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murav’ev, V. P., E-mail: murval1@mail.ru; Kochetkov, A. V.; Glazova, E. G.

A mathematical model and algorithms are proposed for automatic calculation of the optimum flow rate of cooling water in nuclear and thermal power plants with cooling systems of arbitrary complexity. An unlimited number of configuration and design variants are assumed with the possibility of obtaining a result for any computational time interval, from monthly to hourly. The structural solutions corresponding to an optimum cooling water flow rate can be used for subsequent engineering-economic evaluation of the best cooling system variant. The computerized mathematical model and algorithms make it possible to determine the availability and degree of structural changes for themore » cooling system in all stages of the life cycle of a plant.« less

Integrated packaging of multiple double sided cooling planar bond power modules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, Zhenxian

An integrated double sided cooled power module has one or multiple phase legs configuration including one or more planar power packages, each planar power package having an upper power switch unit and a lower power switch unit directly bonded and interconnected between two insulated power substrates, and further sandwiched between two heat exchangers via direct bonds. A segmented coolant manifold is interposed with the one or more planar power packages and creates a sealed enclosure that defines a coolant inlet, a coolant outlet and a coolant flow path between the inlet and the outlet. A coolant circulates along the flowmore » path to remove heat and increase the power density of the power module.« less

Comprehensive Evaluation of Biological Growth Control by Chlorine-Based Biocides in Power Plant Cooling Systems Using Tertiary Effluent

PubMed Central

Chien, Shih-Hsiang; Dzombak, David A.; Vidic, Radisav D.

2013-01-01

Abstract Recent studies have shown that treated municipal wastewater can be a reliable cooling water alternative to fresh water. However, elevated nutrient concentration and microbial population in wastewater lead to aggressive biological proliferation in the cooling system. Three chlorine-based biocides were evaluated for the control of biological growth in cooling systems using tertiary treated wastewater as makeup, based on their biocidal efficiency and cost-effectiveness. Optimal chemical regimens for achieving successful biological growth control were elucidated based on batch-, bench-, and pilot-scale experiments. Biocide usage and biological activity in planktonic and sessile phases were carefully monitored to understand biological growth potential and biocidal efficiency of the three disinfectants in this particular environment. Water parameters, such as temperature, cycles of concentration, and ammonia concentration in recirculating water, critically affected the biocide performance in recirculating cooling systems. Bench-scale recirculating tests were shown to adequately predict the biocide residual required for a pilot-scale cooling system. Optimal residuals needed for proper biological growth control were 1, 2–3, and 0.5–1 mg/L as Cl2 for NaOCl, preformed NH2Cl, and ClO2, respectively. Pilot-scale tests also revealed that Legionella pneumophila was absent from these cooling systems when using the disinfectants evaluated in this study. Cost analysis showed that NaOCl is the most cost-effective for controlling biological growth in power plant recirculating cooling systems using tertiary-treated wastewater as makeup. PMID:23781129

Comprehensive Evaluation of Biological Growth Control by Chlorine-Based Biocides in Power Plant Cooling Systems Using Tertiary Effluent.

PubMed

Chien, Shih-Hsiang; Dzombak, David A; Vidic, Radisav D

2013-06-01

Recent studies have shown that treated municipal wastewater can be a reliable cooling water alternative to fresh water. However, elevated nutrient concentration and microbial population in wastewater lead to aggressive biological proliferation in the cooling system. Three chlorine-based biocides were evaluated for the control of biological growth in cooling systems using tertiary treated wastewater as makeup, based on their biocidal efficiency and cost-effectiveness. Optimal chemical regimens for achieving successful biological growth control were elucidated based on batch-, bench-, and pilot-scale experiments. Biocide usage and biological activity in planktonic and sessile phases were carefully monitored to understand biological growth potential and biocidal efficiency of the three disinfectants in this particular environment. Water parameters, such as temperature, cycles of concentration, and ammonia concentration in recirculating water, critically affected the biocide performance in recirculating cooling systems. Bench-scale recirculating tests were shown to adequately predict the biocide residual required for a pilot-scale cooling system. Optimal residuals needed for proper biological growth control were 1, 2-3, and 0.5-1 mg/L as Cl 2 for NaOCl, preformed NH 2 Cl, and ClO 2 , respectively. Pilot-scale tests also revealed that Legionella pneumophila was absent from these cooling systems when using the disinfectants evaluated in this study. Cost analysis showed that NaOCl is the most cost-effective for controlling biological growth in power plant recirculating cooling systems using tertiary-treated wastewater as makeup.

Design of alumina forming FeCrAl steels for lead or lead-bismuth cooled fast reactors

NASA Astrophysics Data System (ADS)

Lim, Jun; Hwang, Il Soon; Kim, Ji Hyun

2013-10-01

Iron-chromium-aluminum alloys containing 15-20 wt.% Cr and 4-6 wt.% Al have shown excellent corrosion resistance in the temperature range up to 600 °C or higher in liquid lead and lead-bismuth eutectic environments by the formation of protective Al2O3 layers. However, the higher Cr and Al concentrations in ferritic alloys could be problematic because of severe embrittlement in the manufacturing process as well as in service, caused by the formation of brittle phases. For this reason, efforts worldwide have so far mainly focused on the development of aluminizing surface treatments. However, aluminizing surface treatments have major disadvantages of cost, processing difficulties and reliability issues. In this study, a new FeCrAl alloy is proposed for structural materials in lead and lead-bismuth cooled nuclear applications. The alloy design relied on corrosion experiments in high temperature lead and lead-bismuth eutectic environments and computational thermodynamic calculations using the commercial software, JMatPro. The design of new alloys has focused on the optimization of Cr and Al levels for the formation of an external Al2O3 layer which can provide excellent oxidation and corrosion resistance in liquid lead alloys in the temperature range 300-600 °C while still retaining workable mechanical properties.

Recovering hydrocarbons from hydrocarbon-containing vapors

DOEpatents

Mirza, Zia I.; Knell, Everett W.; Winter, Bruce L.

1980-09-30

Values are recovered from a hydrocarbon-containing vapor by contacting the vapor with quench liquid consisting essentially of hydrocarbons to form a condensate and a vapor residue, the condensate and quench fluid forming a combined liquid stream. The combined liquid stream is mixed with a viscosity-lowering liquid to form a mixed liquid having a viscosity lower than the viscosity of the combined liquid stream to permit easy handling of the combined liquid stream. The quench liquid is a cooled portion of the mixed liquid. Viscosity-lowering liquid is separated from a portion of the mixed liquid and cycled to form additional mixed liquid.

Integrated application of combined cooling, heating and power poly-generation PV radiant panel system of zero energy buildings

NASA Astrophysics Data System (ADS)

Yin, Baoquan

2018-02-01

A new type of combined cooling, heating and power of photovoltaic radiant panel (PV/R) module was proposed, and applied in the zero energy buildings in this paper. The energy system of this building is composed of PV/R module, low temperature difference terminal, energy storage, multi-source heat pump, energy balance control system. Radiant panel is attached on the backside of the PV module for cooling the PV, which is called PV/R module. During the daytime, the PV module was cooled down with the radiant panel, as the temperature coefficient influence, the power efficiency was increased by 8% to 14%, the radiant panel solar heat collecting efficiency was about 45%. Through the nocturnal radiant cooling, the PV/R cooling capacity could be 50 W/m2. For the multifunction energy device, the system shows the versatility during the heating, cooling and power used of building utilization all year round.

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

NASA Astrophysics Data System (ADS)

1980-11-01

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

Investigation of a para-ortho hydrogen reactor for application to spacecraft sensor cooling

NASA Technical Reports Server (NTRS)

Nast, T. C.

1983-01-01

The utilization of solid hydrogen in space for sensor and instrument cooling is a very efficient technique for long term cooling or for cooling at high heat rates. The solid hydrogen can provide temperatures as low as 7 to 8 K to instruments. Vapor cooling is utilized to reduce parasitic heat inputs to the 7 to 8 K stage and is effective in providing intermediate cooling for instrument components operating at higher temperatures. The use of solid hydrogen in place of helium may lead to weight reductions as large as a factor of ten and an attendent reduction in system volume. The results of an investigation of a catalytic reactor for use with a solid hydrogen cooling system is presented. Trade studies were performed on several configurations of reactor to meet the requirements of high reactor efficiency with low pressure drop. Results for the selected reactor design are presented for both liquid hydrogen systems operating at near atmospheric pressure and the solid hydrogen cooler operating as low as 1 torr.

Design of a low parasitic inductance SiC power module with double-sided cooling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Fei; Liang, Zhenxian; Wang, Fei

In this paper, a low-parasitic inductance SiC power module with double-sided cooling is designed and compared with a baseline double-sided cooled module. With the unique 3D layout utilizing vertical interconnection, the power loop inductance is effectively reduced without sacrificing the thermal performance. Both simulations and experiments are carried out to validate the design. Q3D simulation results show a power loop inductance of 1.63 nH, verified by the experiment, indicating more than 60% reduction of power loop inductance compared with the baseline module. With 0Ω external gate resistance turn-off at 600V, the voltage overshoot is less than 9% of the busmore » voltage at a load of 44.6A.« less

Efficient and lightweight current leads

NASA Astrophysics Data System (ADS)

Bromberg, L.; Dietz, A. J.; Michael, P. C.; Gold, C.; Cheadle, M.

2014-01-01

Current leads generate substantial cryogenic heat loads in short length High Temperature Superconductor (HTS) distribution systems. Thermal conduction, as well as Joule losses (I2R) along the current leads, comprises the largest cryogenic loads for short distribution systems. Current leads with two temperature stages have been designed, constructed and tested, with the goal of minimizing the electrical power consumption, and to provide thermal margin for the cable. We present the design of a two-stage current lead system, operating at 140 K and 55 K. This design is very attractive when implemented with a turbo-Brayton cycle refrigerator (two-stage), with substantial power and weight reduction. A heat exchanger is used at each temperature station, with conduction-cooled stages in-between. Compact, efficient heat exchangers are challenging, because of the gaseous coolant. Design, optimization and performance of the heat exchangers used for the current leads will be presented. We have made extensive use of CFD models for optimizing hydraulic and thermal performance of the heat exchangers. The methodology and the results of the optimization process will be discussed. The use of demountable connections between the cable and the terminations allows for ease of assembly, but require means of aggressively cooling the region of the joint. We will also discuss the cooling of the joint. We have fabricated a 7 m, 5 kA cable with second generation HTS tapes. The performance of the system will be described.

An experimental study of turbine vane heat transfer with leading edge and downstream film cooling

NASA Astrophysics Data System (ADS)

Nirmalan, V.; Hylton, L. D.

1989-06-01

This paper presents the effects of downstream film cooling, with and without leading edge showerhead film cooling, on turbine-vane external heat transfer. Steady-state experimental measurements were made in a three-vane linear two-dimensional cascade. The principal independent parameters were maintained over ranges consistent with actual engine conditions. The test matrix was structured to provide an assessment of the independent influence of parameters of interest, namely, exit Mach number, exit Reynolds number, coolant-to-gas temperature ratio, and coolant-to-gas pressure ratio. The data obtained indicate that considerable cooling benefits can be achieved by utilizing downstream film cooling. The downstream film cooling process was shown to be a complex interaction of two competing mechanisms. The thermal dilution effect, associated with the injection of relatively cold fluid, results in a decrease in the heat transfer to the airfoil. Conversely, the turbulence augmentation, produced by the injection process, results in increased heat transfer to the airfoil.

An experimental study of turbine vane heat transfer with leading edge and downstream film cooling

NASA Technical Reports Server (NTRS)

Nirmalan, V.; Hylton, L. D.

1989-01-01

This paper presents the effects of downstream film cooling, with and without leading edge showerhead film cooling, on turbine-vane external heat transfer. Steady-state experimental measurements were made in a three-vane linear two-dimensional cascade. The principal independent parameters were maintained over ranges consistent with actual engine conditions. The test matrix was structured to provide an assessment of the independent influence of parameters of interest, namely, exit Mach number, exit Reynolds number, coolant-to-gas temperature ratio, and coolant-to-gas pressure ratio. The data obtained indicate that considerable cooling benefits can be achieved by utilizing downstream film cooling. The downstream film cooling process was shown to be a complex interaction of two competing mechanisms. The thermal dilution effect, associated with the injection of relatively cold fluid, results in a decrease in the heat transfer to the airfoil. Conversely, the turbulence augmentation, produced by the injection process, results in increased heat transfer to the airfoil.

Low power, lightweight vapor sensing using arrays of conducting polymer composite chemically-sensitive resistors

NASA Technical Reports Server (NTRS)

Ryan, M. A.; Lewis, N. S.

2001-01-01

Arrays of broadly responsive vapor detectors can be used to detect, identify, and quantify vapors and vapor mixtures. One implementation of this strategy involves the use of arrays of chemically-sensitive resistors made from conducting polymer composites. Sorption of an analyte into the polymer composite detector leads to swelling of the film material. The swelling is in turn transduced into a change in electrical resistance because the detector films consist of polymers filled with conducting particles such as carbon black. The differential sorption, and thus differential swelling, of an analyte into each polymer composite in the array produces a unique pattern for each different analyte of interest, Pattern recognition algorithms are then used to analyze the multivariate data arising from the responses of such a detector array. Chiral detector films can provide differential detection of the presence of certain chiral organic vapor analytes. Aspects of the spaceflight qualification and deployment of such a detector array, along with its performance for certain analytes of interest in manned life support applications, are reviewed and summarized in this article.

Holmium:YAG (lambda=2120nm) vs. Thulium fiber (lambda=1908nm) laser for high-power vaporization of canine prostate tissue

NASA Astrophysics Data System (ADS)

Casperson, Andrew L.; Barton, Robert A.; Scott, Nicholas J.; Fried, Nathaniel M.

2008-02-01

Direct studies comparing different lasers for treatment of BPH are lacking. This preliminary study compares continuous-wave (CW) vs. pulsed prostate tissue vaporization for the Thulium fiber laser and Holmium:YAG laser, both operating near the 1940 nm water absorption peak in tissue. A 50-W Thulium fiber laser (λ= 1908 nm) delivered CW laser radiation through a 600-μm silica fiber in non-contact mode with a 5-mm-diameter spot at the tissue surface. A Holmium:YAG laser (λ= 2120 nm) operated with an energy of 2 J, pulse rate of 25 Hz, and average power of 50 W, and delivered pulsed laser radiation through a 600-μm silica fiber with a 5-mm-diameter laser spot to achieve similar irradiances at the tissue surface. Tissue vaporization was performed in air with the prostate kept hydrated in saline. Tissue vaporization efficiency of both lasers was compared (n = 10 canine prostates for each laser group). Mean vaporization efficiency measured 5.30 +/- 0.48 kJ/g vs. 4.13 +/- 0.46 kJ/g for Thulium fiber and Holmium lasers (P < 0.05). Tissue vaporization rates measured 0.57 +/- 0.05 g/min vs. 0.73 +/- 0.07 g/min (P < 0.05). The Holmium:YAG laser vaporizes prostate tissue at a higher rate than the Thulium fiber laser, for the same average power delivered to the tissue. Both the Thulium fiber laser and Holmium:YAG lasers are capable of vaporizing prostate tissue at a rate > 1 g/min if operated at the high powers (100-W) typically used in the clinic.

Preconcentrator with high volume chiller for high vapor pressure particle detection

DOEpatents

Linker, Kevin L

2013-10-22

Apparatus and method for collecting particles of both high and low vapor pressure target materials entrained in a large volume sample gas stream. Large volume active cooling provides a cold air supply which is mixed with the sample gas stream to reduce the vapor pressure of the particles. In embodiments, a chiller cools air from ambient conditions to 0-15.degree. C. with the volumetric flow rate of the cold air supply being at least equal to the volumetric flow rate of the sample gas stream. In further embodiments an adsorption media is heated in at least two stages, a first of which is below a threshold temperature at which decomposition products of the high vapor pressure particle are generated.

The Lithium Vapor Box Divertor

NASA Astrophysics Data System (ADS)

Goldston, Robert; Hakim, Ammar; Hammett, Gregory; Jaworski, Michael; Myers, Rachel; Schwartz, Jacob

2015-11-01

Projections of scrape-off layer width to a demonstration power plant suggest an immense parallel heat flux, of order 12 GW/m2, which will necessitate nearly fully detached operation. Building on earlier work by Nagayama et al. and by Ono et al., we propose to use a series of differentially pumped boxes filled with lithium vapor to isolate the buffering vapor from the main plasma chamber, allowing stable detachment. This powerful differential pumping is only available for condensable vapors, not conventional gases. We demonstrate the properties of such a system through conservation laws for vapor mass and enthalpy, and then include plasma entrainment and ultimately an estimate of radiated power. We find that full detachment should be achievable with little leakage of lithium to the main plasma chamber. We also present progress towards solving the Navier-Stokes equation numerically for the chain of vapor boxes, including self-consistent wall boundary conditions and fully-developed shocks, as well as concepts for an initial experimental demonstration-of-concept. This work supported by DOE Contract No. DE-AC02-09CH11466.

Transient Load Following and Control Analysis of Advanced S-CO2 Power Conversion with Dry Air Cooling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moisseytsev, Anton; Sienicki, James J.

2016-01-01

Supercritical carbon dioxide (S-CO2) Brayton cycles are under development as advanced energy converters for advanced nuclear reactors, especially the Sodium-Cooled Fast Reactor (SFR). The use of dry air cooling for direct heat rejection to the atmosphere ultimate heat sink is increasingly becoming a requirement in many regions due to restrictions on water use. The transient load following and control behavior of an SFR with an S-CO2 cycle power converter utilizing dry air cooling have been investigated. With extension and adjustment of the previously existing control strategy for direct water cooling, S-CO2 cycle power converters can also be used for loadmore » following operation in regions where dry air cooling is a requirement« less

Environmental problems associated with decommissioning the Chernobyl Nuclear Power Plant Cooling Pond.

PubMed

Oskolkov, B Ya; Bondarkov, M D; Gaschak, S P; Maksymenko, A M; Maksymenko, V M; Martynenko, V I; Farfán, E B; Jannik, G T; Marra, J C

2010-11-01

Decommissioning of nuclear power plants and other nuclear fuel cycle facilities associated with residual radioactive contamination of their territories is an imperative issue. Significant problems may result from decommissioning of cooling ponds with residual radioactive contamination. The Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond is one of the largest self-contained water reservoirs in the Chernobyl region and Ukrainian and Belorussian Polesye region. The 1986 ChNPP Reactor Unit Number Four significantly contaminated the ChNPP Cooling Pond. The total radionuclide inventory in the ChNPP Cooling Pond bottom deposits are as follows: ¹³⁷Cs: 16.28 ± 2.59 TBq; ⁹⁰Sr: 2.4 ± 0.48 TBq; and ²³⁹+²⁴⁰Pu: 0.00518 ± 0.00148 TBq. The ChNPP Cooling Pond is inhabited by over 500 algae species and subspecies, over 200 invertebrate species, and 36 fish species. The total mass of the living organisms in the ChNPP Cooling Pond is estimated to range from about 60,000 to 100,000 tons. The territory adjacent to the ChNPP Cooling Pond attracts many birds and mammals (178 bird species and 47 mammal species were recorded in the Chernobyl Exclusion Zone). This article describes several options for the ChNPP Cooling Pond decommissioning and environmental problems associated with its decommissioning. The article also provides assessments of the existing and potential exposure doses for the shoreline biota. For the 2008 conditions, the estimated total dose rate values were 11.4 40 μGy h⁻¹ for amphibians, 6.3 μGy h⁻¹ for birds, 15.1 μGy h⁻¹ for mammals, and 10.3 μGy h⁻¹ for reptiles, with the recommended maximum dose rate being equal to 40 μGy h⁻¹. However, drying the ChNPP Cooling Pond may increase the exposure doses to 94.5 μGy h⁻¹ for amphibians, 95.2 μGy h⁻¹ for birds, 284.0 μGy h⁻¹ for mammals, and 847.0 μGy h⁻¹ for reptiles. All of these anticipated dose rates exceed the recommended values.

Combustion chamber struts can be effectively transpiration cooled

NASA Technical Reports Server (NTRS)

Palmer, G. H.

1966-01-01

Vapor-deposited sintering technique increases the feasible temperature range of transpiration-cooled structural members in combustion chambers. This technique produces a porous mass of refractory metal wires around a combustion chamber structural member. This mass acts as a transpiration-cooled surface for a thick-walled tube.

Vapor Bubbles

NASA Astrophysics Data System (ADS)

Prosperetti, Andrea

2017-01-01

This article reviews the fundamental physics of vapor bubbles in liquids. Work on bubble growth and condensation for stationary and translating bubbles is summarized and the differences with bubbles containing a permanent gas stressed. In particular, it is shown that the natural frequency of a vapor bubble is proportional not to the inverse radius, as for a gas bubble, but to the inverse radius raised to the power 2/3. Permanent gas dissolved in the liquid diffuses into the bubble with strong effects on its dynamics. The effects of the diffusion of heat and mass on the propagation of pressure waves in a vaporous bubbly liquid are discussed. Other topics briefly touched on include thermocapillary flow, plasmonic nanobubbles, and vapor bubbles in an immiscible liquid.

High power bipolar lead-acid batteries

NASA Technical Reports Server (NTRS)

Halpert, Gerald; Attia, Alan

1991-01-01

The Jet Propulsion Laboratory (JPL), with interest in advanced energy storage systems, is involved in the development of a unique lead acid battery design. This battery utilizes the same combination of lead and lead dioxide active materials present in the automobile starting battery. However, it can provide 2 to 10 times the power while minimizing volume and weight. The typical starting battery is described as a monopolar type using one current collector for both the positive and negative plate of adjacent cells. Specific power as high as 2.5 kW/kg was projected for 30 second periods with as many as 2000 recharge cycles.

Continuous measurements of water vapor isotopic compositions using an integrated cavity output spectrometer: calibrations and applications

NASA Astrophysics Data System (ADS)

Wang, L.; Caylor, K.; Dragoni, D.

2009-04-01

The 18O and 2H of water vapor can be used to investigate couplings between biological processes (e.g., photosynthesis or transpiration) and hydrologic processes (e.g., evaporation) and therefore serve as powerful tracers in hydrological cycles. A typical method for determining δ18O and δ2H fluxes in landscapes is a "Keeling Plot" approach, which uses field-collected vapor samples coupled with a traditional isotope ratio mass spectrometer to infer the isotopic composition of evapotranspiration. However, fractionation accompanying inefficient vapor trapping can lead to large measurement uncertainty and the intensive laboring involved in cold-trap make it almost impossible for continuous measurements. Over the last 3-4 years a few groups have developed continuous approaches for measuring δ18O and δ2H that use laser absorption spectroscopy (LAS) to achieve accuracy levels similar to lab-based mass spectrometry methods. Unfortunately, most LAS systems need cryogenic cooling, constant calibration to a reference gas, and substantial power requirements, which make them unsuitable for long-term field deployment at remote field sites. In this research, we tested out a new LAS-based water vapor isotope analyzer (WVIA, Los Gatos Research, Inc, Mountain View, CA) based on Integrated Cavity Output Spectroscopy (ICOS) and coupled this instrument with a flux gradient system. The WVIA was calibrated bi-weekly using a dew point generator and water with known δ18O and δ2H signatures. The field work was performed at Morgan-Monroe State Forest Ameriflux tower site (central Indiana) between August 8 and August 27, 2008. The combination method was able to produce hourly δ18O and δ2H fluxes data with reproducibility similar to lab-based mass spectrometry methods. Such high temporal resolution data were also able to capture signatures of canopy and bare soil evaporation to individual rainfall events. The use of the ICOS water vapor analyzer within a gradient system has the

Investigation Of Vapor Explosion Mechanisms Using High Speed Photography

NASA Astrophysics Data System (ADS)

Armstrong, Donn R.; Anderson, Richard P.

1983-03-01

The vapor explosion, a physical interaction between hot and cold liquids that causes the explosive vaporization of the cold liquid, is a hazard of concern in such diverse industries as metal smelting and casting, paper manufacture, and nuclear power generation. Intensive work on this problem worldwide, for the past 25 years has generated a number of theories and mechanisms proposed to explain vapor explosions. High speed photography has been the major instrument used to test the validity of the theories and to provide the observations that have lead to new theories. Examples are given of experimental techniques that have been used to investigate vapor explosions. Detailed studies of specific mechanisms have included microsecond flash photograph of contact boiling and high speed cinematography of shock driven breakup of liquid drops. Other studies looked at the explosivity of various liquid pairs using cinematography inside a pulsed nuclear reactor and x-ray cinematography of a thermite-sodium interaction.

Operating characteristics of a single-stage Stirling cryocooler capable of providing 700 W cooling power at 77 K

NASA Astrophysics Data System (ADS)

Xu, Ya; Sun, Daming; Qiao, Xin; Yu, Yan S. W.; Zhang, Ning; Zhang, Jie; Cai, Yachao

2017-04-01

High cooling capacity Stirling cryocooler generally has hundreds to thousands watts of cooling power at liquid nitrogen temperature. It is promising in boil-off gas (BOG) recondensation and high temperature superconducting (HTS) applications. A high cooling capacity Stirling cryocooler driven by a crank-rod mechanism was developed and studied systematically. The pressure and frequency characteristics of the cryocooler, the heat rejection from the ambient heat exchanger, and the cooling performance are studied under different charging pressure. Energy conversion and distribution in the cryocooler are analyzed theoretically. With an electric input power of 10.9 kW and a rotating speed of 1450 r/min of the motor, a cooling power of 700 W at 77 K and a relative Carnot efficiency of 18.2% of the cryocooler have been achieved in the present study, and the corresponding pressure ratio in the compression space reaches 2.46.

Impact of cool storage air-conditioning in commercial sector on power system operation in Thailand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Surapong, C.; Bundit, L.

The results are presented from an investigation into the potential application for cool storage air-conditioning, and the resultant beneficial impact on power system operation in Thailand is discussed. Field assessment through interviews with decision makers in the identified customer groups produces results that show good potential for cool storage application. Results from a computer program used to calculate power production cost and other characteristics show that substantial benefits would also accrue to the generating utility.

33 CFR 154.826 - Vapor compressors and blowers.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Vapor Control Systems § 154... chamber or cylinder; (2) Excessive cooling water temperature; (3) Excessive vibration; (4) Low lube oil...

33 CFR 154.826 - Vapor compressors and blowers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Vapor Control Systems § 154... chamber or cylinder; (2) Excessive cooling water temperature; (3) Excessive vibration; (4) Low lube oil...

33 CFR 154.826 - Vapor compressors and blowers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) POLLUTION FACILITIES TRANSFERRING OIL OR HAZARDOUS MATERIAL IN BULK Vapor Control Systems § 154... chamber or cylinder; (2) Excessive cooling water temperature; (3) Excessive vibration; (4) Low lube oil...

Review on Water Distribution of Cooling Tower in Power Station

NASA Astrophysics Data System (ADS)

Huichao, Zhang; Lei, Fang; Hao, Guang; Ying, Niu

2018-04-01

As the energy sources situation is becoming more and more severe, the importance of energy conservation and emissions reduction gets clearer. Since the optimization of water distribution system of cooling tower in power station can save a great amount of energy, the research of water distribution system gets more attention nowadays. This paper summarizes the development process of counter-flow type natural draft wet cooling tower and the water distribution system, and introduces the related domestic and international research situation. Combining the current situation, we come to the conclusion about the advantages and disadvantages of the several major water distribution modes, and analyze the problems of the existing water distribution ways in engineering application, furthermore, we put forward the direction of water distribution mode development on the basis knowledge of water distribution of cooling tower. Due to the water system can hardly be optimized again when it’s built, choosing an appropriate water distribution mode according to actual condition seems to be more significant.

Application of local indentations for film cooling of gas turbine blade leading edge

NASA Astrophysics Data System (ADS)

Petelchyts, V. Yu.; Khalatov, A. A.; Pysmennyi, D. N.; Dashevskyy, Yu. Ya.

2016-09-01

The paper presents results of computer simulation of the film cooling on the turbine blade leading edge model where the air coolant is supplied through radial holes and row of cylindrical inclined holes placed inside hemispherical dimples or trench. The blowing factor was varied from 0.5 to 2.0. The model size and key initial parameters for simulation were taken as for a real blade of a high-pressure high-performance gas turbine. Simulation was performed using commercial software code ANSYS CFX. The simulation results were compared with reference variant (no dimples or trench) both for the leading edge area and for the flat plate downstream of the leading edge.

High Stability Performance of Quinary Indium Gallium Zinc Aluminum Oxide Films and Thin-Film Transistors Deposited Using Vapor Cooling Condensation Method

NASA Astrophysics Data System (ADS)

Lin, Yung-Hao; Lee, Ching-Ting

2017-08-01

High-quality indium gallium zinc aluminum oxide (IGZAO) thin films with various Al contents have been deposited using the vapor cooling condensation method. The electron mobility of the IGZAO films was improved by 89.4% on adding Al cation to IGZO film. The change in the electron concentration and mobility of the IGZAO films was 7.3% and 7.0%, respectively, when the temperature was changed from 300 K to 225 K. These experimental results confirm the high performance and stability of the IGZAO films. The performance stability mechanisms of IGZAO thin-film transistors (TFTs) were investigated in comparison with IGZO TFTs.

Mathematical Modeling – The Impact of Cooling Water Temperature Upsurge on Combined Cycle Power Plant Performance and Operation

NASA Astrophysics Data System (ADS)

Indra Siswantara, Ahmad; Pujowidodo, Hariyotejo; Darius, Asyari; Ramdlan Gunadi, Gun Gun

2018-03-01

This paper presents the mathematical modeling analysis on cooling system in a combined cycle power plant. The objective of this study is to get the impact of cooling water upsurge on plant performance and operation, using Engineering Equation Solver (EES™) tools. Power plant installed with total power capacity of block#1 is 505.95 MWe and block#2 is 720.8 MWe, where sea water consumed as cooling media at two unit condensers. Basic principle of analysis is heat balance calculation from steam turbine and condenser, concern to vacuum condition and heat rate values. Based on the result shown graphically, there were impact the upsurge of cooling water to increase plant heat rate and vacuum pressure in condenser so ensued decreasing plant efficiency and causing possibility steam turbine trip as back pressure raised from condenser.

Experimental cooling during incubation leads to reduced innate immunity and body condition in nestling tree swallows.

PubMed

Ardia, Daniel R; Pérez, Jonathan H; Clotfelter, Ethan D

2010-06-22

Nest microclimate can have strong effects that can carry over to later life-history stages. We experimentally cooled the nests of tree swallows (Tachycineta bicolor). Females incubating in cooled nests reduced incubation time and allowed egg temperatures to drop, leading to extended incubation periods. We partially cross-fostered nestlings to test carry-over effects of cooling during incubation on nestling innate constitutive immunity, assessed through bacteria killing ability (BKA) of blood. Nestlings that had been cooled as eggs showed a lower ability to kill bacteria than control nestlings, regardless of the treatment of their foster mother. However, there was no effect of treatment of rearing females on nestling BKA in control nestlings, even though cooled females made significantly fewer feeding visits than did control females. This suggests that the effect of cooling occurred during incubation and was not due to carry-over effects on nestling condition. Nestlings that were exposed to experimental cooling as embryos had lower residual body mass and absolute body mass at all four ages measured. Our results indicate that environmental conditions and trade-offs experienced during one stage of development can have important carry-over effects on later life-history stages.

Injection locking of a high power ultraviolet laser diode for laser cooling of ytterbium atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hosoya, Toshiyuki; Miranda, Martin; Inoue, Ryotaro

2015-07-15

We developed a high-power laser system at a wavelength of 399 nm for laser cooling of ytterbium atoms with ultraviolet laser diodes. The system is composed of an external cavity laser diode providing frequency stabilized output at a power of 40 mW and another laser diode for amplifying the laser power up to 220 mW by injection locking. The systematic method for optimization of our injection locking can also be applied to high power light sources at any other wavelengths. Our system does not depend on complex nonlinear frequency-doubling and can be made compact, which will be useful for providing light sources formore » laser cooling experiments including transportable optical lattice clocks.« less

Rugged passively cooled high power laser fiber optic connectors and methods of use

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rinzler, Charles C.; Gray, William C.; Fraze, Jason D.

2016-06-07

There are provided high power laser connectors and couplers and methods that are capable of providing high laser power without the need for active cooling to remote, harsh and difficult to access locations and under difficult and harsh conditions and to manage and mitigate the adverse effects of back reflections.

Stratified vapor generator

DOEpatents

Bharathan, Desikan [Lakewood, CO; Hassani, Vahab [Golden, CO

2008-05-20

A stratified vapor generator (110) comprises a first heating section (H.sub.1) and a second heating section (H.sub.2). The first and second heating sections (H.sub.1, H.sub.2) are arranged so that the inlet of the second heating section (H.sub.2) is operatively associated with the outlet of the first heating section (H.sub.1). A moisture separator (126) having a vapor outlet (164) and a liquid outlet (144) is operatively associated with the outlet (124) of the second heating section (H.sub.2). A cooling section (C.sub.1) is operatively associated with the liquid outlet (144) of the moisture separator (126) and includes an outlet that is operatively associated with the inlet of the second heating section (H.sub.2).

Achieving more reliable operation of turbine generators at nuclear power plants by improving the water chemistry of the generator stator cooling system

NASA Astrophysics Data System (ADS)

Tyapkov, V. F.; Chudakova, I. Yu.; Alekseenko, O. A.

2011-08-01

Ways of improving the water chemistry used in the turbine generator stator's cooling systems at Russian nuclear power plants are considered. Data obtained from operational chemical monitoring of indicators characterizing the quality of cooling water in the turbine generator stator cooling systems of operating power units at nuclear power plants are presented.

Macro-channel cooled high power fiber coupled diode lasers exceeding 1.2kW of output power

NASA Astrophysics Data System (ADS)

Koenning, Tobias; Alegria, Kim; Wang, Zuolan; Segref, Armin; Stapleton, Dean; Faßbender, Wilhelm; Flament, Marco; Rotter, Karsten; Noeske, Axel; Biesenbach, Jens

2011-03-01

We report on a new series of fiber coupled diode laser modules exceeding 1.2kW of single wavelength optical power from a 400um / 0.2NA fiber. The units are constructed from passively cooled laser bars as opposed to other comparably powered, commercially available modules that use micro-channel heat-sinks. Micro-channel heat sinks require cooling water to meet demanding specifications and are therefore prone to failures due to contamination and increase the overall cost to operate and maintain the laser. Dilas' new series of high power fiber coupled diode lasers are designed to eliminate micro channel coolers and their associated failure mechanisms. Low-smile soldering processes were developed to maximize the brightness available from each diode laser bar. The diode laser brightness is optimally conserved using Dilas' recently developed propriety laser bar stacking geometry and optics. A total of 24 bars are coupled into a single fiber core using a polarization multiplexing scheme. The modular design permits further power scaling through wavelength multiplexing. Other customer critical features such as industrial grade fibers, pilot beams, fiber interlocks and power monitoring are standard features on these modules. The optical design and the beam parameter calculations will be presented to explain the inherit design trade offs. Results for single and dual wavelengths modules will be presented.

Legionnaires' disease bacteria in power plant cooling systems: Phase 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tyndall, R.L.; Christensen, S.W.; Solomon, J.A.

1985-04-01

Legionnaires' Disease Bacteria (Legionella) are a normal component of the aquatic community. The study investigated various environmental factors that affect Legionella profiles in power plant cooling waters. The results indicate that each of the four factors investigated (incubation temperature, water quality, the presence and type of associated biota, and the nature of the indigenous Legionella population) is important in determining the Legionella profile of these waters. Simple predictive relationships were not found. At incubation temperatures of 32/sup 0/ and 37/sup 0/C, waters from a power plant where infectious Legionella were not observed stimulated the growth of stock Legionella cultures moremore » than did waters from plants where infectious Legionella were prevalent. This observation is consistent with Phase I results, which showed that densities of Legionella were frequently reduced in closed-cycle cooling systems despite the often higher infectivity of Legionella in closed-cycle waters. In contrast, water from power plants where infectious Legionella were prevalent supported the growth of indigenous Legionella pneumophila at 42/sup 0/C, while water from a power plant where infectious Legionella were absent did not support growth of indigenous Legionella. Some Legionella are able to withstand a water temperature of 85/sup 0/C for several hours, thus proving more tolerant than was previously realized. Finally, the observation that water from two power plants where infectious Legionella were prevalent usually supported the growth of Group A Legionella at 45/sup 0/C indicates the presence, of soluble Legionella growth promoters in these waters. This test system could allow for future identification and control of these growth promoters and, hence, of Legionella. 25 refs., 23 figs., 10 tabs.« less

Modeling physical vapor deposition of energetic materials

DOE PAGES

Shirvan, Koroush; Forrest, Eric C.

2018-03-28

Morphology and microstructure of organic explosive films formed using physical vapor deposition (PVD) processes strongly depends on local surface temperature during deposition. Currently, there is no accurate means of quantifying the local surface temperature during PVD processes in the deposition chambers. This study focuses on using a multiphysics computational fluid dynamics tool, STARCCM+, to simulate pentaerythritol tetranitrate (PETN) deposition. The PETN vapor and solid phase were simulated using the volume of fluid method and its deposition in the vacuum chamber on spinning silicon wafers was modeled. The model also included the spinning copper cooling block where the wafers are placedmore » along with the chiller operating with forced convection refrigerant. Implicit time-dependent simulations in two- and three-dimensional were performed to derive insights in the governing physics for PETN thin film formation. PETN is deposited at the rate of 14 nm/s at 142.9 °C on a wafer with an initial temperature of 22 °C. The deposition of PETN on the wafers was calculated at an assumed heat transfer coefficient (HTC) of 400 W/m 2 K. This HTC proved to be the most sensitive parameter in determining the local surface temperature during deposition. Previous experimental work found noticeable microstructural changes with 0.5 mm fused silica wafers in place of silicon during the PETN deposition. This work showed that fused silica slows initial wafer cool down and results in ~10 °C difference for the surface temperature at 500 μm PETN film thickness. It was also found that the deposition surface temperature is insensitive to the cooling power of the copper block due to the copper block's very large heat capacity and thermal conductivity relative to the heat input from the PVD process. Future work should incorporate the addition of local stress during PETN deposition. Lastly, based on simulation results, it is also recommended to investigate the impact of wafer

Modeling physical vapor deposition of energetic materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shirvan, Koroush; Forrest, Eric C.

Morphology and microstructure of organic explosive films formed using physical vapor deposition (PVD) processes strongly depends on local surface temperature during deposition. Currently, there is no accurate means of quantifying the local surface temperature during PVD processes in the deposition chambers. This study focuses on using a multiphysics computational fluid dynamics tool, STARCCM+, to simulate pentaerythritol tetranitrate (PETN) deposition. The PETN vapor and solid phase were simulated using the volume of fluid method and its deposition in the vacuum chamber on spinning silicon wafers was modeled. The model also included the spinning copper cooling block where the wafers are placedmore » along with the chiller operating with forced convection refrigerant. Implicit time-dependent simulations in two- and three-dimensional were performed to derive insights in the governing physics for PETN thin film formation. PETN is deposited at the rate of 14 nm/s at 142.9 °C on a wafer with an initial temperature of 22 °C. The deposition of PETN on the wafers was calculated at an assumed heat transfer coefficient (HTC) of 400 W/m 2 K. This HTC proved to be the most sensitive parameter in determining the local surface temperature during deposition. Previous experimental work found noticeable microstructural changes with 0.5 mm fused silica wafers in place of silicon during the PETN deposition. This work showed that fused silica slows initial wafer cool down and results in ~10 °C difference for the surface temperature at 500 μm PETN film thickness. It was also found that the deposition surface temperature is insensitive to the cooling power of the copper block due to the copper block's very large heat capacity and thermal conductivity relative to the heat input from the PVD process. Future work should incorporate the addition of local stress during PETN deposition. Lastly, based on simulation results, it is also recommended to investigate the impact of wafer

Vapor bubble evolution on a heated surface containing open microchannels

NASA Astrophysics Data System (ADS)

Forster, Christopher J.; Glezer, Ari; Smith, Marc K.

2011-11-01

Power electronics require cooling technologies capable of high heat fluxes at or below the operating temperatures of these devices. Boiling heat transfer is an effective choice for such cooling, but it is limited by the critical heat flux (CHF), which is typically near 125 W/cm2 for pool boiling of water on a flat plate at standard pressure and gravity. One method of increasing CHF is to incorporate an array of microchannels into the heated surface. Microchannels have been experimentally shown to improve CHF, and the goal of this study is to determine the primary mechanisms associated with the microchannels that allow for the increased CHF. While the use of various microstructures is not new, the emphasis of previous work has been on heat transfer aspects, as opposed to the fluid dynamics inside and in the vicinity of the microchannels. This work considers the non-isothermal fluid motion during bubble growth and departure by varying channel geometry, spacing, and heat flux input using a level-set method including vaporization and condensation. These results and the study of the underlying mechanisms will aid in the design optimization of microchannel-based cooling devices. Supported by ONR.

Numerical Investigations of the Influence of Unsteady Vane Trailing Edge Shock Wave on Film Cooling Effectiveness of Rotor Blade Leading Edge

NASA Astrophysics Data System (ADS)

Wang, Yufeng; Cai, Le; Wang, Songtao; Zhou, Xun

2018-04-01

Unsteady numerical simulations of a high-load transonic turbine stage have been carried out to study the influences of vane trailing edge outer-extending shockwave on rotor blade leading edge film cooling performance. The turbine stage used in this paper is composed of a vane section and a rotor one which are both near the root section of a transonic high-load turbine stage. The Mach number is 0.94 at vane outlet, and the relative Mach number is above 1.10 at rotor outlet. Various positions and oblique angles of film cooling holes were investigated in this research. Results show that the cooling efficiency on the blade surface of rotor near leading edge is significantly affected by vane trailing edge outer-extending shockwave in some cases. In the cases that film holes are close to leading edge, cooling performance suffers more from the sweeping vane trailing edge outer-extending shockwave. In addition, coolant flow ejected from oblique film holes is harder to separate from the blade surface of rotor, and can cover more blade area even under the effects of sweeping vane trailing edge shockwave. As a result, oblique film holes can provide better film cooling performance than vertical film holes do near the leading edge on turbine blade which is swept by shockwaves.

Drying of pulverized material with heated condensible vapor

DOEpatents

Carlson, L.W.

1984-08-16

Apparatus for drying pulverized material utilizes a high enthalpy condensable vapor such as steam for removing moisture from the individual particles of the pulverized material. The initially wet particulate material is tangentially delivered by a carrier vapor flow to an upper portion of a generally vertical cylindrical separation drum. The lateral wall of the separation drum is provided with a plurality of flow guides for directing the vapor tangentially therein in the direction of particulate material flow. Positioned concentrically within the separation drum and along the longitudinal axis thereof is a water-cooled condensation cylinder which is provided with a plurality of collection plates, or fines, on the outer lateral surface thereof. The cooled collection fines are aligned counter to the flow of the pulverized material and high enthalpy vapor mixture to maximize water vapor condensation thereon. The condensed liquid which includes moisture removed from the pulverized materials then flows downward along the outer surface of the coolant cylinder and is collected and removed. The particles travel in a shallow helix due to respective centrifugal and vertical acceleration forces applied thereto. The individual particles of the pulverized material are directed outwardly by the vortex flow where they contact the inner cylindrical surface of the separation drum and are then deposited at the bottom thereof for easy collection and removal. The pulverized material drying apparatus is particularly adapted for drying coal fines and facilitates the recovery of the pulverized coal. 2 figs.

Drying of pulverized material with heated condensible vapor

DOEpatents

Carlson, Larry W.

1986-01-01

Apparatus for drying pulverized material utilizes a high enthalpy condensable vapor such as steam for removing moisture from the individual particles of the pulverized material. The initially wet particulate material is tangentially delivered by a carrier vapor flow to an upper portion of a generally vertical cylindrical separation drum. The lateral wall of the separation drum is provided with a plurality of flow guides for directing the vapor tangentially therein in the direction of particulate material flow. Positioned concentrically within the separation drum and along the longitudinal axis thereof is a water-cooled condensation cylinder which is provided with a plurality of collection plates, or fins, on the outer lateral surface thereof. The cooled collection fins are aligned counter to the flow of the pulverized material and high enthalpy vapor mixture to maximize water vapor condensation thereon. The condensed liquid which includes moisture removed from the pulverized material then flows downward along the outer surface of the coolant cylinder and is collected and removed. The particles travel in a shallow helix due to respective centrifugal and vertical acceleration forces applied thereto. The individual particles of the pulverized material are directed outwardly by the vortex flow where they contact the inner cylindrical surface of the separation drum and are then deposited at the bottom thereof for easy collection and removal. The pulverized material drying apparatus is particularly adapted for drying coal fines and facilitates the recovery of the pulverized coal.

Passive Vaporizing Heat Sink

NASA Technical Reports Server (NTRS)

Knowles, TImothy R.; Ashford, Victor A.; Carpenter, Michael G.; Bier, Thomas M.

2011-01-01

A passive vaporizing heat sink has been developed as a relatively lightweight, compact alternative to related prior heat sinks based, variously, on evaporation of sprayed liquids or on sublimation of solids. This heat sink is designed for short-term dissipation of a large amount of heat and was originally intended for use in regulating the temperature of spacecraft equipment during launch or re-entry. It could also be useful in a terrestrial setting in which there is a requirement for a lightweight, compact means of short-term cooling. This heat sink includes a hermetic package closed with a pressure-relief valve and containing an expendable and rechargeable coolant liquid (e.g., water) and a conductive carbon-fiber wick. The vapor of the liquid escapes when the temperature exceeds the boiling point corresponding to the vapor pressure determined by the setting of the pressure-relief valve. The great advantage of this heat sink over a melting-paraffin or similar phase-change heat sink of equal capacity is that by virtue of the =10x greater latent heat of vaporization, a coolant-liquid volume equal to =1/10 of the paraffin volume can suffice.

User's manual for the BNW-I optimization code for dry-cooled power plants. Volume I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braun, D.J.; Daniel, D.J.; De Mier, W.V.

1977-01-01

This User's Manual provides information on the use and operation of three versions of BNW-I, a computer code developed by Battelle, Pacific Northwest Laboratory (PNL) as a part of its activities under the ERDA Dry Cooling Tower Program. These three versions of BNW-I were used as reported elsewhere to obtain comparative incremental costs of electrical power production by two advanced concepts (one using plastic heat exchangers and one using ammonia as an intermediate heat transfer fluid) and a state-of-the-art system. The computer program offers a comprehensive method of evaluating the cost savings potential of dry-cooled heat rejection systems and componentsmore » for power plants. This method goes beyond simple ''figure-of-merit'' optimization of the cooling tower and includes such items as the cost of replacement capacity needed on an annual basis and the optimum split between plant scale-up and replacement capacity, as well as the purchase and operating costs of all major heat rejection components. Hence, the BNW-I code is a useful tool for determining potential cost savings of new heat transfer surfaces, new piping or other components as part of an optimized system for a dry-cooled power plant.« less

Hydraulic design of a re-circulating water cooling system of a combined cycle power plant in Thailand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarkar, C.K.; Pandit, D.R.; Kwon, S.G.

The paper describes the hydraulic design and hydraulic transient analysis of the re-circulating water cooling system of the combined cyclo Sipco power cogeneration plant in Thailand. The power plant of 450 MW total capacity is proposed to be built in two stages. Stage one will produce 300 MW of power and will consist of two gas turbine generators (GTG) and one steam turbine generator (STG). Stage two will produce 150 MW of power and will consist of one GTG and one STG. The cooling system will consist of one GTG and one STG. The cooling system will consist of coolingmore » towers, a combined collecting basin and pump intake sump, pumps and motors, and separate conveyance systems and condensers for the generator units in the two stages. In a re-circulating water cooling system, cold water is pumped from the pump intake sump to the condensers through the conveyance system and hot water from the condensers is carried through the returning pipeline system to the cooling towers, whence the water after cooling is drained into the sump at the base of the towers. Total cooling water requirement for the system in stage one is estimated to be 112,000 gallons per minute (GPM), and that in stage two, 56,000 GPM. The sump is designed using the computer program HEC-2, developed by the US Army Corps of Engineers (COE) and the pump intake basin, following the recommendations of the Hydraulic Institute. The pumps were sized by computing the head loss in the system, and, the steady state and transient performances (during pump start-up and shut-down procedures and due to possible power or mechanical failure of one or all pumps) of the system were analyzed by mathematically modeling the system using the computer program WHAMO (Water Hammer nd Mass Oscillations), also developed by the COE.« less

Cool Down Experiences with the SST-1 Helium Cryogenics System before and after Current Feeders System Modification

NASA Astrophysics Data System (ADS)

Patel, R.; Panchal, P.; Panchal, R.; Tank, J.; Mahesuriya, G.; Sonara, D.; Srikanth, G. L. N.; Garg, A.; Bairagi, N.; Christian, D.; Patel, K.; Shah, P.; Nimavat, H.; Sharma, R.; Patel, J. C.; Gupta, N. C.; Prasad, U.; Sharma, A. N.; Tanna, V. L.; Pradhan, S.

The SST-1 machine comprises a superconducting magnet system (SCMS), which includes TF and PF magnets. In order to charge the SCMS, we need superconducting current feeders consisting of SC feeders and vapor cooled current leads (VCCLs). We have installed all 10 (+/-) pairs of VCCLs for the TF and PF systems. While conducting initial engineering validation of the SST-1 machine, our prime objective was to produce circular plasma using only the TF system. During the SST-1 campaign I to VI, we have to stop the PF magnets cooling in order to get the cryo- stable conditions for current charging of the TF magnets system. In that case, the cooling of the PF current leads is not essential. It has been also observed that after aborting the PF system cooling, there was a limited experimental window of TF operation. Therefore, in the recent SST-1 campaign-VII, we removed the PF current leads (9 pairs) and kept only single (+/-) pair of the 10,000 A rated VCCLs to realize the charging of the TF system for the extended window of operation. We have observed a better cryogenic stability in the TF magnets after modifications in the CFS. In this paper, we report the comparison of the cool down performance for the SST-1 machine operation before and after modifications of the current feeders system.

The maximal cooling power of magnetic and thermoelectric refrigerators with La(FeCoSi)13 alloys

NASA Astrophysics Data System (ADS)

Skokov, K. P.; Karpenkov, A. Yu.; Karpenkov, D. Yu.; Gutfleisch, O.

2013-05-01

Using our data on magnetic entropy change ΔSm, adiabatic temperature change ΔTad and heat capacity CH for La(FeCoSi)13 alloys, the upper limit of heat Qc transferred per cycle, and the lowest limit of consumed work Wc were established for magnetic refrigerators operating in Δμ0H =1.9 T. In order to estimate the cooling power, attributable to thermoelectric refrigerators with La(FeCoSi)13, thermal conductivity λ, resistivity ρ, and Seebeck coefficient α were measured and the maximal cooling power QL, the input power Pi, and coefficient of performance have been calculated.

Performance of the Conduction-Cooled LDX Levitation Coil

NASA Astrophysics Data System (ADS)

Michael, P. C.; Schultz, J. H.; Smith, B. A.; Titus, P. H.; Radovinsky, A.; Zhukovsky, A.; Hwang, K. P.; Naumovich, G. J.; Camille, R. J.

2004-06-01

The Levitated Dipole Experiment (LDX) was developed to study plasma confinement in a dipole magnetic field. Plasma is confined in the magnetic field of a 680-kg Nb3Sn Floating Coil (F-coil) that is electromagnetically supported at the center of a 5-m diameter by 3-m tall vacuum chamber. The Levitation Coil (L-coil) is a 2800-turn, double pancake winding that supports the weight of the F-coil and controls its vertical position within the vacuum chamber. The use of high-temperature superconductor (HTS) Bi-2223 for the L-coil minimizes the electrical and cooling power needed for levitation. The L-coil winding pack and support plate are suspended within the L-coil cryostat and cooled by conduction to a single-stage cryocooler rated for 25-W heat load at approximately 20 K. The coil current leads consist of conduction-cooled copper running from room temperature to 80 K and a pair of commercially-available, 150-A HTS leads. An automatically filled liquid-nitrogen reservoir provides cooling for the coil's radiation shield and for the leads' 80-K heat stations. This paper discusses the L-coil system design and its observed cryogenic performance.

Environmental Problems Associated with Decommissioning of Chernobyl Power Plant Cooling Pond

NASA Astrophysics Data System (ADS)

Foley, T. Q.; Oskolkov, B. Y.; Bondarkov, M. D.; Gashchak, S. P.; Maksymenko, A. M.; Maksymenko, V. M.; Martynenko, V. I.; Jannik, G. T.; Farfan, E. B.; Marra, J. C.

2009-12-01

Decommissioning of nuclear power plants and other nuclear fuel cycle facilities associated with residual radioactive contamination is a fairly pressing issue. Significant problems may result from decommissioning of cooling ponds. The Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond is one of the largest self-contained bodies of water in the Chernobyl Region and Ukrainian Polesye with a water surface area of 22.9 km2. The major hydrological feature of the ChNPP Cooling Pond is that its water level is 6-7 m higher than the water level in the Pripyat River and water losses due to seepage and evaporation are replenished by pumping water from the Pripyat River. In 1986, the accident at the ChNPP #4 Reactor Unit significantly contaminated the ChNPP Cooling Pond. According to the 2001 data, the total radionuclide inventory in the ChNPP Cooling Pond bottom deposits was as follows: 16.28 ± 2.59 TBq for 137Cs; 2.4 ± 0.48 TBq for 90Sr, and 0.00518 ± 0.00148 TBq for 239+240Pu. Since ChNPP is being decommissioned, the ChNPP Cooling Pond of such a large size will no longer be needed and cost effective to maintain. However, shutdown of the water feed to the Pond would expose the contaminated bottom deposits and change the hydrological features of the area, destabilizing the radiological and environmental situation in the entire region in 2007 - 2008, in order to assess potential consequences of draining the ChNPP Cooling Pond, the authors conducted preliminary radio-ecological studies of its shoreline ecosystems. The radioactive contamination of the ChNPP Cooling Pond shoreline is fairly variable and ranges from 75 to 7,500 kBq/m2. Three areas with different contamination levels were selected to sample soils, vegetation, small mammals, birds, amphibians, and reptilians in order to measure their 137Cs and 90Sr content. Using the ERICA software, their dose exposures were estimated. For the 2008 conditions, the estimated dose rates were found to be as follows: amphibians - 11

Atom Interferometry in a Warm Vapor

DOE PAGES

Biedermann, G. W.; McGuinness, H. J.; Rakholia, A. V.; ...

2017-04-17

Here, we demonstrate matter-wave interference in a warm vapor of rubidium atoms. Established approaches to light-pulse atom interferometry rely on laser cooling to concentrate a large ensemble of atoms into a velocity class resonant with the atom optical light pulse. In our experiment, we show that clear interference signals may be obtained without laser cooling. This effect relies on the Doppler selectivity of the atom interferometer resonance. Lastly, this interferometer may be configured to measure accelerations, and we demonstrate that multiple interferometers may be operated simultaneously by addressing multiple velocity classes.

Ultrahigh temperature vapor core reactor-MHD system for space nuclear electric power

NASA Technical Reports Server (NTRS)

Maya, Isaac; Anghaie, Samim; Diaz, Nils J.; Dugan, Edward T.

1991-01-01

The conceptual design of a nuclear space power system based on the ultrahigh temperature vapor core reactor with MHD energy conversion is presented. This UF4 fueled gas core cavity reactor operates at 4000 K maximum core temperature and 40 atm. Materials experiments, conducted with UF4 up to 2200 K, demonstrate acceptable compatibility with tungsten-molybdenum-, and carbon-based materials. The supporting nuclear, heat transfer, fluid flow and MHD analysis, and fissioning plasma physics experiments are also discussed.

Ex vivo evaluation of safety and efficacy of vaporization of the prostate using a 300 W high-power laser diode with the wavelength of 980 nm

NASA Astrophysics Data System (ADS)

Takada, Junya; Honda, Norihiro; Hazama, Hisanao; Awazu, Kunio

2014-03-01

Laser vaporization of the prostate is one of the promising technique for less-invasive treatment of benign prostatic hyperplasia. However, shorter operative duration and higher hemostatic ability are expected. The wavelength of 980 nm offers a high simultaneous absorption by water and hemoglobin, so that it combines the efficient vaporization with good hemostasis. Therefore, we have evaluated the safety and efficacy of vaporization of the prostate using a recently developed 300 W high-power laser diode with the wavelength of 980 nm. First, validity of bovine prostate tissue as the sample was confirmed by measuring the optical properties of bovine and human prostate tissue using a double integrating sphere optical system. Next, contact and non-contact ex vivo irradiations were performed for various irradiation powers and times, and vaporized and coagulated depths were measured. In the contact irradiation, the vaporized depth at the power of 300 W was significantly deeper than that at the power of 100 W, while the difference was relatively smaller for the coagulated depths at 300 and 100 W. In the non-contact irradiation, coagulation as thick as that in the contact irradiation was observed almost without vaporization. Therefore, it is suggested that the treatment in the contact irradiation using the high-power laser diode can vaporize the prostate more efficiently without increasing the risk of perforation. Hemostasis with the coagulation would be possible in both irradiation methods. To prevent the postoperative perforation, operators need to understand the relationship between the coagulated depth and the irradiation conditions.

Cooling Spheres and Accumulating Lead: The History of Attempts to Date the Earth's Formation.

ERIC Educational Resources Information Center

Brush, Stephen G.

1987-01-01

Presents a chronology of scientific efforts designed to determine the age of the earth. Summarizes scientists' attempts at dating the planet's formation, including the examination of lead in the environment, the calculation of the earth's cooling temperature and time, the study of geological sedimentation and the analysis of moon rocks. (TW)

Integrated Thermal Modules for Cooling Silicon and Silicon Carbide Power Modules

DTIC Science & Technology

2007-06-11

analyses, bench tests, and motor tests comprise the program. The ITMs, in place of standard heatsinks, use a highly conductive pyrolytic graphite to...passively cool power modules. Initial results show that even simple ITMs can lower chip temperatures by 20 deg. C and 10 deg. C with engine oil and

Magnetocaloric Materials and the Optimization of Cooling Power Density

NASA Technical Reports Server (NTRS)

Wikus, Patrick; Canavan, Edgar; Heine, Sarah Trowbridge; Matsumoto, Koichi; Numazawa, Takenori

2014-01-01

The magnetocaloric effect is the thermal response of a material to an external magnetic field. This manuscript focuses on the physics and the properties of materials which are commonly used for magnetic refrigeration at cryogenic temperatures. After a brief overview of the magnetocaloric effect and associated thermodynamics, typical requirements on refrigerants are discussed from a standpoint of cooling power density optimization. Finally, a compilation of the most important properties of several common magnetocaloric materials is presented.

Pressure intelligent control strategy of Waste heat recovery system of converter vapors

NASA Astrophysics Data System (ADS)

Feng, Xugang; Wu, Zhiwei; Zhang, Jiayan; Qian, Hong

2013-01-01

The converter gas evaporative cooling system is mainly used for absorbing heat in the high temperature exhaust gas which produced by the oxygen blowing reaction. Vaporization cooling steam pressure control system of converter is a nonlinear, time-varying, lagging behind, close coupling of multivariable control object. This article based on the analysis of converter operation characteristics of evaporation cooling system, of vaporization in a production run of pipe pressure variation and disturbance factors.For the dynamic characteristics of the controlled objects,we have improved the conventional PID control scheme.In Oxygen blowing process, we make intelligent control by using fuzzy-PID cascade control method and adjusting the Lance,that it can realize the optimization of the boiler steam pressure control.By design simulation, results show that the design has a good control not only ensures drum steam pressure in the context of security, enabling efficient conversion of waste heat.And the converter of 1800 flue gas through pipes and cool and dust removal also can be cooled to about 800. Therefore the converter haze evaporative cooling system has achieved to the converter haze temperature decrease effect and enhanced to the coal gas returns-ratio.

Water Vapor Permeability of the Advanced Crew Escape Suit

NASA Technical Reports Server (NTRS)

Bue, Grant; Kuznetz, Larry; Gillis, David; Jones, Jeffery; Daniel, Brian; Gernhardt, Michael; Hamilton, Douglas

2009-01-01

Crew Exploration Vehicle (CEV) crewmembers are expected to return to earth wearing a suit similar to the current Advanced Crew Escape Suit (ACES). To ensure optimum cognitive performance, suited crewmembers must maintain their core body temperature within acceptable limits. There are currently several options for thermal maintenance in the post-landing phase. These include the current baseline, which uses an ammonia boiler, purge flow using oxygen in the suit, accessing sea water for liquid cooling garment (LCG) cooling and/or relying on the evaporative cooling capacity of the suit. These options vary significantly in mass, power, engineering and safety factors, with relying on the evaporative cooling capacity of the suit being the least difficult to implement. Data from previous studies indicates that the evaporative cooling capacity of the ACES was much higher than previously expected, but subsequent tests were performed for longer duration and higher metabolic rates to better define the water vapor permeability of the ACES. In these tests five subjects completed a series of tests performing low to moderate level exercise in order to control for a target metabolic rate while wearing the ACES in an environmentally controlled thermal chamber. Four different metabolic profiles at a constant temperature of 95 F and relative humidity of 50% were evaluated. These tests showed subjects were able to reject about twice as much heat in the permeable ACES as they were in an impermeable suit that had less thermal insulation. All of the heat rejection differential is attributed to the increased evaporation capability through the Gortex bladder of the suit.

Vapor phase elemental sulfur amendment for sequestering mercury in contaminated soil

DOEpatents

Looney, Brian B.; Denham, Miles E.; Jackson, Dennis G.

2014-07-08

The process of treating elemental mercury within the soil is provided by introducing into the soil a heated vapor phase of elemental sulfur. As the vapor phase of elemental sulfur cools, sulfur is precipitated within the soil and then reacts with any elemental mercury thereby producing a reaction product that is less hazardous than elemental mercury.

CVB: The Constrained Vapor Bubble 40 mm Capillary Experiment on the ISS

NASA Technical Reports Server (NTRS)

Wayner, Peter C., Jr.; Kundan, Akshay; Plawsky, Joel

2013-01-01

Discuss the Constrained Vapor Bubble (CVB) 40mm Fin experiment on the ISS and how it aims to achieve a better understanding of the physics of evaporation and condensation and how they affect cooling processes in microgravity using a remotely controlled microscope and a small cooling device

Ultralow-power local laser control of the dimer density in alkali-metal vapors through photodesorption

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jha, Pankaj K.; Scully, Marlan O.; Princeton University, Princeton, New Jersey 08544

2012-08-27

Ultralow-power diode-laser radiation is employed to induce photodesorption of cesium from a partially transparent thin-film cesium adsorbate on a solid surface. Using resonant Raman spectroscopy, we demonstrate that this photodesorption process enables an accurate local optical control of the density of dimer molecules in alkali-metal vapors.

A latitudinal survey of mesospheric and upper stratospheric water vapor

NASA Technical Reports Server (NTRS)

Croskey, C. L.; Martone, J. P.; Olivero, J. J.; Puliafito, S. E.

1994-01-01

As part of the LAtitudinal DIstribution of Middle Atmosphere Structure (LADIMAS) campaign, measurements of mesospheric and upper stratospheric water vapor concentration were made over a latitudinal range from 53 N to 63 S. The 22-GHz emission line of water vapor was observed by a new, portable, cryogenically cooled microwave radiometer that was carried on board the German research vessel Polarstern as it sailed from Bremerhaven, Germany, to the Antarctic during November and December, 1991. Water vapor profiles were obtained at approximately 5 deg latitude intervals for an altitude range of 40 to 80 km.

Mechano-caloric cooling device

NASA Technical Reports Server (NTRS)

Frederking, T. H. K.; Luna, Jack; Abbassi, P.; Carandang, R. M.

1989-01-01

The mechano-caloric effect is potentially useful in the He II temperature range. Aside from demonstration work, little quantification effort appears to have been known since other refrigeration possibilities have been available for some time. Successful He II use-related system examples are as follows: in space, the utilization of the latent heat of vaporization has been quite successful in vapor-liquid phase separation (VLPS) in conjunction with thermomechanical force application in plugs. In magnet cooling systems, the possibility of using the mechano-caloric cooling effect in conjunction with thermo-mechanical circulation pump schemes, has been assessed (but not quantified yet to the extent desirable). A third example is quoted in conjunction with superfluid wind tunnel studies and liquid helium tow tank for surface vessels respectively. In all of these (partially future) R and D areas, the question of refrigerator effectiveness using the mechano-caloric effect appears to be relevant, possibly in conjunction with questions of reliability and simplicity. The present work is concerned with quantification of phenomena including simplified thermodynamic cycle calculations.

Computation of leading edge film cooling from a CONSOLE geometry (CONverging Slot hOLE)

NASA Astrophysics Data System (ADS)

Guelailia, A.; Khorsi, A.; Hamidou, M. K.

2016-01-01

The aim of this study is to investigate the effect of mass flow rate on film cooling effectiveness and heat transfer over a gas turbine rotor blade with three staggered rows of shower-head holes which are inclined at 30° to the spanwise direction, and are normal to the streamwise direction on the blade. To improve film cooling effectiveness, the standard cylindrical holes, located on the leading edge region, are replaced with the converging slot holes (console). The ANSYS CFX has been used for this computational simulation. The turbulence is approximated by a k-ɛ model. Detailed film effectiveness distributions are presented for different mass flow rate. The numerical results are compared with experimental data.

Performance of Air-cooled Engine Cylinders Using Blower Cooling

NASA Technical Reports Server (NTRS)

Schey, Oscar W; Ellerbrock, Herman H , Jr

1936-01-01

An investigation was made to obtain information on the minimum quantity of air and power required to cool conventional air cooled cylinders at various operating conditions when using a blower. The results of these tests show that the minimum power required for satisfactory cooling with an overall blower efficiency of 100 percent varied from 2 to 6 percent of the engine power depending on the operating conditions. The shape of the jacket had a large effect on the cylinder temperatures. Increasing the air speed over the front of the cylinder by keeping the greater part of the circumference of the cylinder covered by the jacket reduced the temperatures over the entire cylinder.

9 CFR 354.244 - Temperatures and cooling and freezing procedures.

Code of Federal Regulations, 2013 CFR

2013-01-01

... wrapped or packaged in water-vapor resistant cartons or the containers should be lined with heavy water... carcasses and to permit unsealed closure or sealing in such a manner that water-vapor loss from the product... cooling tank containing running cold tap water to remove the animal heat from the carcass. Carcasses shall...

9 CFR 354.244 - Temperatures and cooling and freezing procedures.

Code of Federal Regulations, 2012 CFR

2012-01-01

... wrapped or packaged in water-vapor resistant cartons or the containers should be lined with heavy water... carcasses and to permit unsealed closure or sealing in such a manner that water-vapor loss from the product... cooling tank containing running cold tap water to remove the animal heat from the carcass. Carcasses shall...

9 CFR 354.244 - Temperatures and cooling and freezing procedures.

Code of Federal Regulations, 2011 CFR

2011-01-01

... wrapped or packaged in water-vapor resistant cartons or the containers should be lined with heavy water... carcasses and to permit unsealed closure or sealing in such a manner that water-vapor loss from the product... cooling tank containing running cold tap water to remove the animal heat from the carcass. Carcasses shall...

9 CFR 354.244 - Temperatures and cooling and freezing procedures.

Code of Federal Regulations, 2014 CFR

2014-01-01

... wrapped or packaged in water-vapor resistant cartons or the containers should be lined with heavy water... carcasses and to permit unsealed closure or sealing in such a manner that water-vapor loss from the product... cooling tank containing running cold tap water to remove the animal heat from the carcass. Carcasses shall...

Startup of Pumping Units in Process Water Supplies with Cooling Towers at Thermal and Nuclear Power Plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berlin, V. V., E-mail: vberlin@rinet.ru; Murav’ev, O. A., E-mail: muraviov1954@mail.ru; Golubev, A. V., E-mail: electronik@inbox.ru

Aspects of the startup of pumping units in the cooling and process water supply systems for thermal and nuclear power plants with cooling towers, the startup stages, and the limits imposed on the extreme parameters during transients are discussed.

A 1.8K refrigeration cryostat with 100 hours continuous cooling

NASA Astrophysics Data System (ADS)

Xu, Dong; Li, Jian; Huang, Rongjin; Li, Laifeng

2017-02-01

A refrigeration cryostat has been developed to produce continuous cooling to a sample below 1.8 K over 100 hours by using a cryocooler. A two-stage 4K G-M cryocooler is used to liquefy helium gas from evacuated vapor and cylinder helium bottle which can be replaced during the cooling process. The liquid helium transfer into superfluid helium in a Joule-Thomson valve in connection with a 1000 m3/h pumping unit. The pressure of evacuated helium vapor is controlled by air bag and valves. A copper decompression chamber, which is designed as a cooling station to control the superfluid helium, is used to cool the sample attached on it uniformly. The sample connects to the copper chamber in cryostat with screw thread. The cryostat can reach the temperature of 1.7 K without load and the continuous working time is more than 100 hours.

AP1000{sup R} nuclear power plant safety overview for spent fuel cooling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gorgemans, J.; Mulhollem, L.; Glavin, J.

2012-07-01

The AP1000{sup R} plant is an 1100-MWe class pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance, safety and costs. The AP1000 design uses passive features to mitigate design basis accidents. The passive safety systems are designed to function without safety-grade support systems such as AC power, component cooling water, service water or HVAC. Furthermore, these passive features 'fail safe' during a non-LOCA event such that DC power and instrumentation are not required. The AP1000 also has simple, active, defense-in-depth systems to support normal plant operations. These active systems provide the first levelmore » of defense against more probable events and they provide investment protection, reduce the demands on the passive features and support the probabilistic risk assessment. The AP1000 passive safety approach allows the plant to achieve and maintain safe shutdown in case of an accident for 72 hours without operator action, meeting the expectations provided in the U.S. Utility Requirement Document and the European Utility Requirements for passive plants. Limited operator actions are required to maintain safe conditions in the spent fuel pool via passive means. In line with the AP1000 approach to safety described above, the AP1000 plant design features multiple, diverse lines of defense to ensure spent fuel cooling can be maintained for design-basis events and beyond design-basis accidents. During normal and abnormal conditions, defense-in-depth and other systems provide highly reliable spent fuel pool cooling. They rely on off-site AC power or the on-site standby diesel generators. For unlikely design basis events with an extended loss of AC power (i.e., station blackout) or loss of heat sink or both, spent fuel cooling can still be provided indefinitely: - Passive systems, requiring minimal or no operator actions, are sufficient for at least 72 hours under all

A LWIR hyperspectral imager using a Sagnac interferometer and cooled HgCdTe detector array

NASA Astrophysics Data System (ADS)

Lucey, Paul G.; Wood, Mark; Crites, Sarah T.; Akagi, Jason

2012-06-01

LWIR hyperspectral imaging has a wide range of civil and military applications with its ability to sense chemical compositions at standoff ranges. Most recent implementations of this technology use spectrographs employing varying degrees of cryogenic cooling to reduce sensor self-emission that can severely limit sensitivity. We have taken an interferometric approach that promises to reduce the need for cooling while preserving high resolution. Reduced cooling has multiple benefits including faster system readiness from a power off state, lower mass, and potentially lower cost owing to lower system complexity. We coupled an uncooled Sagnac interferometer with a 256x320 mercury cadmium telluride array with an 11 micron cutoff to produce a spatial interferometric LWIR hyperspectral imaging system operating from 7.5 to 11 microns. The sensor was tested in ground-ground applications, and from a small aircraft producing spectral imagery including detection of gas emission from high vapor pressure liquids.

Water vapor diffusion membrane development

NASA Technical Reports Server (NTRS)

Tan, M. K.

1977-01-01

An application of the water vapor diffusion technique is examined whereby the permeated water vapor is vented to space vacuum to alleviate on-board waste storage and provide supplemental cooling. The work reported herein deals primarily with the vapor diffusion-heat rejection (VD-HR) as it applies to the Space Shuttle. A stack configuration was selected, designed and fabricated. An asymmetric cellulose acetate membrane, used in reverse osmosis application was selected and a special spacer was designed to enhance mixing and promote mass transfer. A skid-mount unit was assembled from components used in the bench unit although no attempt was made to render it flight-suitable. The operating conditions of the VD-HR were examined and defined and a 60-day continuous test was carried out. The membranes performed very well throughout the test; no membrane rupture and no unusual flux decay was observed. In addition, a tentative design for a flight-suitable VD-HR unit was made.

Reflux cooling experiments on the NCSU scaled PWR facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doster, J.M.; Giavedoni, E.

1993-01-01

Under loss of forced circulation, coupled with the loss or reduction in primary side coolant inventory, horizontal stratified flows can develop in the hot and cold legs of pressurized water reactors (PWRs). Vapor produced in the reactor vessel is transported through the hot leg to the steam generator tubes where it condenses and flows back to the reactor vessel. Within the steam generator tubes, the flow regimes may range from countercurrent annular flow to single-phase convection. As a result, a number of heat transfer mechanisms are possible, depending on the loop configuration, total heat transfer rate, and the steam flowmore » rate within the tubes. These include (but are not limited to) two-phase natural circulation, where the condensate flows concurrent to the vapor stream and is transported to the cold leg so that the entire reactor coolant loop is active, and reflux cooling, where the condensate flows back down the interior of the coolant tubes countercurrent to the vapor stream and is returned to the reactor vessel through the hot leg. While operating in the reflux cooling mode, the cold leg can effectively be inactive. Heat transfer can be further influenced by noncondensables in the vapor stream, which accumulate within the upper regions of the steam generator tube bundle. In addition to reducing the steam generator's effective heat transfer area, under these conditions operation under natural circulation may not be possible, and reflux cooling may be the only viable heat transfer mechanism. The scaled PWR (SPWR) facility in the nuclear engineering department at North Carolina State Univ. (NCSU) is being used to study the effectiveness of two-phase natural circulation and reflux cooling under conditions associated with loss of forced circulation, midloop coolant levels, and noncondensables in the primary coolant system.« less

Presence of pathogenic amoebae in power plant cooling waters. Final report, October 15, 1977-September 30, 1979. [Naegleria fowleri

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tyndall, R.L.; Willaert, E.; Stevens, A.R.

1981-03-01

Cooling-water-associated algae and sediments from five northern and five southern or western electric power plants were tested for the presence of pathogenic amoebae. In addition, water algae and sediments from five northern and five southern/western sites not associated with power plants were tested. There was a significant correlation at northern power plants between the presence of thermophilic, pathogenic amoebae in cooling waters and thermal additions. Presence of the pathogenic did not correlate with salinity, pH, conductivity, or a variety of various chemical components of the cooling waters. Selected pathogenic isolates were tested serologically and were classified as Naegleria fowleri. Althoughmore » thermal additions were shown to be contributing factor in predisposing cooling waters to the growth of pathogenic amoebae, the data suggest the involvement of other currently undefined parameters associated with the presence of the pathogenic amoebae. 35 refs., 21 tabs.« less

Vapor chamber with hollow condenser tube heat sink

NASA Astrophysics Data System (ADS)

Ong, K. S.; Haw, P. L.; Lai, K. C.; Tan, K. H.

2017-04-01

Heat pipes are heat transfer devices capable of transferring large quantities of heat effectively and efficiently. A vapor chamber (VC) is a flat heat pipe. A novel VC with hollow condenser tubes embedded on the top of it is proposed. This paper reports on the experimental thermal performance of three VC devices embedded with hollow tubes and employed as heat sinks. The first device consisted of a VC with a single hollow tube while the other two VCs had an array of multi-tubes with different tube lengths. All three devices were tested under natural and force air convection cooling. An electrical resistance heater was employed to provide power inputs of 10 and 40 W. Surface temperatures were measured with thermocouple probes at different locations around the devices. The results show that temperatures increased with heater input while total device thermal resistances decreased. Force convection results in lower temperatures and lower resistance. Dry-out occurs at high input power and with too much condensing area. There appears to be an optimum fill ratio which depended upon dimensions of the VC and also heating power.

A MASS-SPECTROMETRIC INVESTIGATION OF SULFUR VAPOR AS A FUNCTION OF TEMPERATURE (thesis)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zietz, M.C.

1960-06-15

A mass-spectrometric investigation was performed on sulfur vapor in equilibrium with the condensed phase at 120 to 210 gas-cooled C. It was found that, in this temperature range, equilibrium sulfur vapor contains appreciable quantities of S/sub 8/, S/sub 7/, S/sub 6/, and S/sub 5/ only. The sulfur vapor emanated as a small well-collimated molecular beam from a specially constructed source into an ionization chamber which was designed to exclude from analysis any sulfur vapor that had impinged on the walls or the hot electron filament. Essential identical ionization potentials were determined for S/sub 8/ , S/sub 7/, S/sub 6/, andmore » S/sub 5/ of 9.8 0.4 ev. The heat of vaporizati on of S/sub 7/ was calculated to be approximately 2.5 kcal greater than that of S/ sub 8/. Upper limits for S/sub 8/ and S/sub 7/ composition in S vapor at 120 gas- cooled C were determined to be 86% and 14%, respectively. It is proposed thst S/sub 8/ is the vaporizing species, that S/sub 7/, S/sub 6/, and S/sub 5/ result from dissociation of S/sub 8/. and that all four molecules have a ring configuration. (auth)« less

Vapor-liquid phase separator studies

NASA Technical Reports Server (NTRS)

Yuan, S. W. K.; Lee, J. M.; Kim, Y. I.; Hepler, W. A.; Frederking, T. H. K.

1983-01-01

Porous plugs serve as both entropy rejection devices and phase separation components separating the vapor phase on the downstream side from liquid Helium 2 upstream. The liquid upstream is the cryo-reservoir fluid needed for equipment cooling by means of Helium 2, i.e Helium-4 below its lambda temperature in near-saturated states. The topics outlined are characteristic lengths, transport equations and plug results.

Evaporative Cooling Membrane Device

NASA Technical Reports Server (NTRS)

Lomax, Curtis (Inventor); Moskito, John (Inventor)

1999-01-01

An evaporative cooling membrane device is disclosed having a flat or pleated plate housing with an enclosed bottom and an exposed top that is covered with at least one sheet of hydrophobic porous material having a thin thickness so as to serve as a membrane. The hydrophobic porous material has pores with predetermined dimensions so as to resist any fluid in its liquid state from passing therethrough but to allow passage of the fluid in its vapor state, thereby, causing the evaporation of the fluid and the cooling of the remaining fluid. The fluid has a predetermined flow rate. The evaporative cooling membrane device has a channel which is sized in cooperation with the predetermined flow rate of the fluid so as to produce laminar flow therein. The evaporative cooling membrane device provides for the convenient control of the evaporation rates of the circulating fluid by adjusting the flow rates of the laminar flowing fluid.

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

NASA Astrophysics Data System (ADS)

Li, Kenneth

2014-02-01

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

Custom ceramic microchannel-cooled array for high-power fiber-coupled application

NASA Astrophysics Data System (ADS)

Junghans, Jeremy; Feeler, Ryan; Stephens, Ed

2018-03-01

A low-SWaP (Size, Weight and Power) diode array has been developed for a high-power fiber-coupled application. High efficiency ( 65%) diodes enable high optical powers while minimizing thermal losses. A large amount of waste heat is still generated and must be extracted. Custom ceramic microchannel-coolers (MCCs) are used to dissipate the waste heat. The custom ceramic MCC was designed to accommodate long cavity length diodes and micro-lenses. The coolers provide similar thermal performance as copper MCCs however they are not susceptible to erosion and can be cooled with standard filtered water. The custom ceramic micro-channel cooled array was designed to be a form/fit replacement for an existing copperbased solution. Each array consisted of three-vertically stacked MCCs with 4 mm CL, 976 nm diodes and beamshaping micro-optics. The erosion and corrosion resistance of ceramic array is intended to mitigate the risk of copperbased MCC corrosion failures. Elimination of the water delivery requirements (pH, resistivity and dissolved oxygen control) further reduces the system SWaP while maintaining reliability. The arrays were fabricated and fully characterized. This work discusses the advantages of the ceramic MCC technology and describes the design parameters that were tailored for the fiber-coupled application. Additional configuration options (form/fit, micro-lensing, alternate coolants, etc.) and on-going design improvements are also discussed.

The Use of Water Vapor for Detecting Environments that Lead to Convectively Produced Heavy Precipitation and Flash Floods

NASA Technical Reports Server (NTRS)

Scofield, Rod; Vicente, Gilberto; Hodges, Mike

2000-01-01

This Tech Report summarizes years of study and experiences on using GOES Water vapor (6.7 micron and precipitable water) and Special Sensor Microwave Imager (SSM/1) from the Defense Meteorological Satellite Program (DMSP) derived Precipitable Water (PNAI) for detecting environments favorable for convectively produced flash floods. An emphasis is on the moisture. upper air flow, and equivalent potential temperature (Theta(sub e)) patterns that lead to devastating flood events. The 15 minute 6.7 micron water vapor imagery is essential for tracking middle to upper tropospheric disturbances that produce upward vertical motion and initiate flash flood producing systems. Water vapor imagery at 6.7 micron is also used to detect surges of upper level moisture (called tropical water vapor plumes) that have been associated with extremely heavy rainfall. Since the water vapor readily depicts lifting mechanisms and upper level moisture, water vapor imagery is often an excellent source of data for recognizing patterns of heavy precipitation and flash floods. In order to analyze the depth of the moisture, the PW aspects of the troposphere must be measured. The collocation (or nearby location) of high values ofP\\V and instability are antecedent conditions prior to the flash flood or heavy rainfall events. Knowledge of PW magnitudes have been used as thresholds for impending flash flood events, PW trends are essential in flash flood prediction. Conceptual models and water vapor products are used to study some of the characteristics of convective systems that occurred over the United States of America (USA) during the summer of 1997 and the 1997-1998 El Nino. P\\V plumes were associated with most of the \\vest coast heavy precipitation events examined during the winter season of 1997 - 1998, In another study, conducted during the summer season of 1997. results showed that the collocation of water vapor (6.7 micron) and P\\N' plumes possessed higher correlations with predicted

Development of a design model for airfoil leading edge film cooling

NASA Astrophysics Data System (ADS)

Wadia, A. R.; Nealy, D. A.

1985-03-01

A series of experiments on scaled cylinder models having injection through holes inclined at 20, 30, 45, and 90 degrees are presented. The experiments were conducted in a wind tunnel on several stainless steel test specimens in which flow and heat transfer parameters were measured over simulated airfoil leading edge surfaces. On the basis of the experimental results, an engineering design model is proposed that treats the gas-to-surface heat transfer coefficient with film cooling in a manner suggested by Luckey and L'Ecuyer (1981). It is shown that the main factor influencing the averaged film cooling effectiveness in the showerhead region is the inclination of the injection holes. The effectiveness parameter was not affected by variations in the coolant-to-gas stream pressure ratio, the freestream Mach number, the gas to coolant temperature ratio, or the gas stream Reynolds number. Experience in the wind tunnel tests is reflected in the design of the model in which the coolant side heat transfer coefficient is offset by a simultaneous increase in the gas side film coefficient. The design applications of the analytical model are discussed, with emphasis given to high temperature first stage turbine vanes and rotor blades.

Lead/acid batteries in systems to improve power quality

NASA Astrophysics Data System (ADS)

Taylor, P.; Butler, P.; Nerbun, W.

Increasing dependence on computer technology is driving needs for extremely high-quality power to prevent loss of information, material, and workers' time that represent billions of dollars annually. This cost has motivated commercial and Federal research and development of energy storage systems that detect and respond to power-quality failures in milliseconds. Electrochemical batteries are among the storage media under investigation for these systems. Battery energy storage systems that employ either flooded lead/acid or valve-regulated lead/acid battery technologies are becoming commercially available to capture a share of this emerging market. Cooperative research and development between the US Department of Energy and private industry have led to installations of lead/acid-based battery energy storage systems to improve power quality at utility and industrial sites and commercial development of fully integrated, modular battery energy storage system products for power quality. One such system by AC Battery Corporation, called the PQ2000, is installed at a test site at Pacific Gas and Electric Company (San Ramon, CA, USA) and at a customer site at Oglethorpe Power Corporation (Tucker, GA, USA). The PQ2000 employs off-the-shelf power electronics in an integrated methodology to control the factors that affect the performance and service life of production-model, low-maintenance, flooded lead/acid batteries. This system, and other members of this first generation of lead/acid-based energy storage systems, will need to compete vigorously for a share of an expanding, yet very aggressive, power quality market.

Evaporative Cooling in a Holographic Atom Trap

NASA Technical Reports Server (NTRS)

Newell, Raymond

2003-01-01

We present progress on evaporative cooling of Rb-87 atoms in our Holographic Atom Trap (HAT). The HAT is formed by the interference of five intersecting YAG laser beams: atoms are loaded from a vapor-cell MOT into the bright fringes of the interference pattern through the dipole force. The interference pattern is composed of Talbot fringes along the direction of propagation of the YAG beams, prior to evaporative cooling each Talbot fringe contains 300,000 atoms at 50 micro-K and peak densities of 2 x 10(exp 14)/cu cm. Evaporative cooling is achieved through adiabatically decreasing the intensity of the YAG laser. We present data and calculations covering a range of HAT geometries and cooling procedures.

Passive Cooling of Body Armor

NASA Astrophysics Data System (ADS)

Holtz, Ronald; Matic, Peter; Mott, David

2013-03-01

Warfighter performance can be adversely affected by heat load and weight of equipment. Current tactical vest designs are good insulators and lack ventilation, thus do not provide effective management of metabolic heat generated. NRL has undertaken a systematic study of tactical vest thermal management, leading to physics-based strategies that provide improved cooling without undesirable consequences such as added weight, added electrical power requirements, or compromised protection. The approach is based on evaporative cooling of sweat produced by the wearer of the vest, in an air flow provided by ambient wind or ambulatory motion of the wearer. Using an approach including thermodynamic analysis, computational fluid dynamics modeling, air flow measurements of model ventilated vest architectures, and studies of the influence of fabric aerodynamic drag characteristics, materials and geometry were identified that optimize passive cooling of tactical vests. Specific architectural features of the vest design allow for optimal ventilation patterns, and selection of fabrics for vest construction optimize evaporation rates while reducing air flow resistance. Cooling rates consistent with the theoretical and modeling predictions were verified experimentally for 3D mockups.

Design of a fuel element for a lead-cooled fast reactor

NASA Astrophysics Data System (ADS)

Sobolev, V.; Malambu, E.; Abderrahim, H. Aït

2009-03-01

The options of a lead-cooled fast reactor (LFR) of the fourth generation (GEN-IV) reactor with the electric power of 600 MW are investigated in the ELSY Project. The fuel selection, design and optimization are important steps of the project. Three types of fuel are considered as candidates: highly enriched Pu-U mixed oxide (MOX) fuel for the first core, the MOX containing between 2.5% and 5.0% of the minor actinides (MA) for next core and Pu-U-MA nitride fuel as an advanced option. Reference fuel rods with claddings made of T91 ferrite-martensitic steel and two alternative fuel assembly designs (one uses a closed hexagonal wrapper and the other is an open square variant without wrapper) have been assessed. This study focuses on the core variant with the closed hexagonal fuel assemblies. Based on the neutronic parameters provided by Monte-Carlo modeling with MCNP5 and ALEPH codes, simulations have been carried out to assess the long-term thermal-mechanical behaviour of the hottest fuel rods. A modified version of the fuel performance code FEMAXI-SCK-1, adapted for fast neutron spectrum, new fuels, cladding materials and coolant, was utilized for these calculations. The obtained results show that the fuel rods can withstand more than four effective full power years under the normal operation conditions without pellet-cladding mechanical interaction (PCMI). In a variant with solid fuel pellets, a mild PCMI can appear during the fifth year, however, it remains at an acceptable level up to the end of operation when the peak fuel pellet burnup ∼80 MW d kg-1 of heavy metal (HM) and the maximum clad damage of about 82 displacements per atom (dpa) are reached. Annular pellets permit to delay PCMI for about 1 year. Based on the results of this simulation, further steps are envisioned for the optimization of the fuel rod design, aiming at achieving the fuel burnup of 100 MW d kg-1 of HM.

Non-Cooled Power System for Venus Lander

NASA Technical Reports Server (NTRS)

Salazar, Denise; Landis, Geoffrey A.; Colozza, Anthony J.

2014-01-01

The Planetary Science Decadal Survey of 2013-2022 stated that the exploration of Venus is of significant interest. Studying the seismic activity of the planet is of particular importance because the findings can be compared to the seismic activity of Earth. Further, the geological and atmospheric properties of Venus will shed light into the past and future of Earth. This paper presents a radioisotope power system (RPS) design for a small low-power Venus lander. The feasibility of the new power system is then compared to that of primary batteries. A requirement for the power source system is to avoid moving parts in order to not interfere with the primary objective of the mission - to collect data about the seismic activity of Venus using a seismometer. The target mission duration of the lander is 117 days, a significant leap from Venera 13, the longest-lived lander on the surface of Venus, which survived for 2 hours. One major assumption for this mission design is that the power source system will not provide cooling to the other components of the lander. This assumption is based on high-temperature electronics technology that will enable the electronics and components of the lander to operate at Venus surface temperature. For the proposed RPS, a customized General Purpose Heat Source Radioisotope Thermoelectric Generator (GPHSRTG) is designed and analyzed. The GPHS-RTG is chosen primarily because it has no moving parts and it is capable of operating for long duration missions on the order of years. This power system is modeled as a spherical structure for a fundamental thermal analysis. The total mass and electrical output of the system are calculated to be 24 kilograms and 26 Watts, respectively. An alternative design for a battery-based power system uses Sodium Sulfur batteries. To deliver a similar electrical output for 117 days, the battery mass is calculated to be 234 kilograms. Reducing mission duration or power required will reduce the required battery mass

System and method for pre-cooling of buildings

DOEpatents

Springer, David A.; Rainer, Leo I.

2011-08-09

A method for nighttime pre-cooling of a building comprising inputting one or more user settings, lowering the indoor temperature reading of the building during nighttime by operating an outside air ventilation system followed, if necessary, by a vapor compression cooling system. The method provides for nighttime pre-cooling of a building that maintains indoor temperatures within a comfort range based on the user input settings, calculated operational settings, and predictions of indoor and outdoor temperature trends for a future period of time such as the next day.

Columnar jointing in vapor-phase-altered, non-welded Cerro Galán Ignimbrite, Paycuqui, Argentina

USGS Publications Warehouse

Wright, Heather M.; Lesti, Chiara; Cas, Ray A.F.; Porreca, Massimiliano; Viramonte, Jose G.; Folkes, Christopher B.; Giordano, Guido

2011-01-01

Columnar jointing is thought to occur primarily in lavas and welded pyroclastic flow deposits. However, the non-welded Cerro Galán Ignimbrite at Paycuqui, Argentina, contains well-developed columnar joints that are instead due to high-temperature vapor-phase alteration of the deposit, where devitrification and vapor-phase crystallization have increased the density and cohesion of the upper half of the section. Thermal remanent magnetization analyses of entrained lithic clasts indicate high emplacement temperatures, above 630°C, but the lack of welding textures indicates temperatures below the glass transition temperature. In order to remain below the glass transition at 630°C, the minimum cooling rate prior to deposition was 3.0 × 10−3–8.5 × 10−2°C/min (depending on the experimental data used for comparison). Alternatively, if the deposit was emplaced above the glass transition temperature, conductive cooling alone was insufficient to prevent welding. Crack patterns (average, 4.5 sides to each polygon) and column diameters (average, 75 cm) are consistent with relatively rapid cooling, where advective heat loss due to vapor fluxing increases cooling over simple conductive heat transfer. The presence of regularly spaced, complex radiating joint patterns is consistent with fumarolic gas rise, where volatiles originated in the valley-confined drainage system below. Joint spacing is a proxy for cooling rates and is controlled by depositional thickness/valley width. We suggest that the formation of joints in high-temperature, non-welded deposits is aided by the presence of underlying external water, where vapor transfer causes crystallization in pore spaces, densifies the deposit, and helps prevent welding.

Vapor-deposited organic glasses exhibit enhanced stability against photodegradation.

PubMed

Qiu, Yue; Dalal, Shakeel S; Ediger, M D

2018-04-18

Photochemically stable solids are in demand for applications in organic electronics. Previous work has established the importance of the molecular packing environment by demonstrating that different crystal polymorphs of the same compound react at different rates when illuminated. Here we show, for the first time, that different amorphous packing arrangements of the same compound photodegrade at different rates. For these experiments, we utilize the ability of physical vapor deposition to prepare glasses with an unprecedented range of densities and kinetic stabilities. Indomethacin, a pharmaceutical molecule that can undergo photodecarboxylation when irradiated by UV light, is studied as a model system. Photodegradation is assessed through light-induced changes in the mass of glassy thin films due to the loss of CO2, as measured by a quartz crystal microbalance (QCM). Glasses prepared by physical vapor deposition degraded more slowly under UV illumination than did the liquid-cooled glass, with the difference as large as a factor of 2. Resistance to photodegradation correlated with glass density, with the vapor-deposited glasses being up to 1.3% more dense than the liquid-cooled glass. High density glasses apparently limit the local structural changes required for photodegradation.

Effect of Air Cooling of Turbine Disk on Power and Efficiency of Turbine from Turbo Engineering Corporation TT13-18 Turbosupercharger.

NASA Technical Reports Server (NTRS)

Berkey, William E.

1949-01-01

An investigation was conducted to determine the effect of turbine-disk cooling with air on the efficiency and the power output of the radial-flow turbine from the Turbo Engineering Corporation TT13-18 turbosupercharger. The turbine was operated at a constant range of ratios of turbine-inlet total pressure to turbine-outlet static pressure of 1,5 and 2.0, turbine-inlet total pressure of 30 inches mercury absolute, turbine-inlet total temperature of 12000 to 20000 R, and rotor speeds of 6000 to 22,000 rpm, Over the normal operating range of the turbine, varying the corrected cooling-air weight flow from approximately 0,30 to 0.75 pound per second produced no measurable effect on the corrected turbine shaft horsepower or the turbine shaft adiabatic efficiency. Varying the turbine-inlet total temperature from 12000 to 20000 R caused no measurable change in the corrected cooling-air weight flow. Calculations indicated that the cooling-air pumping power in the disk passages was small and was within the limits of the accuracy of the power measurements. For high turbine power output, the power loss to the compressor for compressing the cooling air was approximately 3 percent of the total turbine shaft horsepower.

Rapid freezing without cooling equilibration in canine sperm.

PubMed

Kim, Suhee; Lee, Yongcheol; Yang, Honghyun; Kim, Yong-Jun

2012-01-01

The aim of this study was to develop a rapid method of canine semen freezing without cooling equilibration using treatment with different cryoprotectant agents (CPAs) and freezing in liquid nitrogen (LN(2)) vapor in a 0.5-mL straw via modifying vitrification. Ejaculates from eight beagle dogs were frozen with different CPAs (CPA-free, 5% glycerol, 5% ethylene glycol, and 10% ethylene glycol) and freezing times (direct plunging into LN(2) or freezing for 1, 2, 3, or 10 min in LN(2) vapor before plunging into LN(2)). Frozen-thawed sperm were evaluated for motility, viability, normal morphology, and plasma- and acrosome-membrane integrities. The 5% glycerol treatment resulted in improved sperm motility, plasma-membrane integrity and acrosome-membrane integrity (P<0.05). Freezing in LN(2) vapor showed improved sperm motility, viability, and plasma membrane integrity (P<0.05), and freezing for more than 2 min in LN(2) vapor increased acrosome-membrane integrity compared with direct plunging into LN(2) (P<0.05). The direct plunging into LN(2) showed no motile sperm. However, freezing for more than 2 min in LN(2) vapor increased the total abnormalities compared to direct plunging into LN(2) (P<0.05). In conclusion, use of 5% glycerol and freezing in LN(2) vapor were essential for the rapid freezing of canine sperm without cooling equilibration. In particular, holding for 2 min in LN(2) vapor was sufficient to yield successful rapid freezing. This rapid freezing method is simple and effective in canine sperm and would be helpful to offer information for trial of vitrification in large volumes of canine sperm. Copyright © 2012 Elsevier B.V. All rights reserved.

Influence of the helium-pressure on diode-pumped alkali-vapor laser

NASA Astrophysics Data System (ADS)

Gao, Fei; Chen, Fei; Xie, Ji-jiang; Zhang, Lai-ming; Li, Dian-jun; Yang, Gui-long; Guo, Jing

2013-05-01

Diode-pumped alkali-vapor laser (DPAL) is a kind of laser attracted much attention for its merits, such as high quantum efficiency, excellent beam quality, favorable thermal management, and potential scalability to high power and so on. Based on the rate-equation theory of end-pumped DPAL, the performances of DPAL using Cs-vapor collisionally broadened by helium are simulated and studied. With the increase of helium pressure, the numerical results show that: 1) the absorption line-width increases and the stimulated absorption cross-section decreases contrarily; 2) the threshold pumping power decreases to minimum and then rolls over to increase linearly; 3) the absorption efficiency rises to maximum initially due to enough large stimulated absorption cross-section in the far wings of collisionally broadened D2 transition (absorption transition), and then begins to reduce; 4) an optimal value of helium pressure exists to obtain the highest output power, leading to an optimal optical-optical efficiency. Furthermore, to generate the self-oscillation of laser, a critical value of helium pressure occurs when small-signal gain equals to the threshold gain.

New class of compounds have very low vapor pressures

NASA Technical Reports Server (NTRS)

Angell, C. A.; Gruen, D. M.

1967-01-01

Magnesium hexahydrate tetrachlorometallates are 50-volume-percent water, have a high melting point and possess a low vapor pressure. These new compounds are relatively noncorrosive, thermally stable, and water soluble but not hygroscopic. They may have potential applications as cooling fluids.

Turbine Vane External Heat Transfer. Volume 1: Analytical and Experimental Evaluation of Surface Heat Transfer Distributions with Leading Edge Showerhead Film Cooling

NASA Technical Reports Server (NTRS)

Turner, E. R.; Wilson, M. D.; Hylton, L. D.; Kaufman, R. M.

1985-01-01

Progress in predictive design capabilities for external heat transfer to turbine vanes was summarized. A two dimensional linear cascade (previously used to obtain vane surface heat transfer distributions on nonfilm cooled airfoils) was used to examine the effect of leading edge shower head film cooling on downstream heat transfer. The data were used to develop and evaluate analytical models. Modifications to the two dimensional boundary layer model are described. The results were used to formulate and test an effective viscosity model capable of predicting heat transfer phenomena downstream of the leading edge film cooling array on both the suction and pressure surfaces, with and without mass injection.

19. RW Meyer Sugar: 18761889. Cooling Shed Interior, 1881. View: ...

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

19. RW Meyer Sugar: 1876-1889. Cooling Shed Interior, 1881. View: Looking toward west end of cooling shed. After the concentrated syrup flowed out of the sorghum pan it cooled and crystallized in large sugar coolers. The humidity and vapors caused by the sorghum pan would have retarded the crystallizing and cooling of the sugar in the boiling house. In 1881 this shed was constructed to house the coolers and the sugar before it was dried in the centrifugals. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Modeling Two-Phase Flow and Vapor Cycles Using the Generalized Fluid System Simulation Program

NASA Technical Reports Server (NTRS)

Smith, Amanda D.; Majumdar, Alok K.

2017-01-01

This work presents three new applications for the general purpose fluid network solver code GFSSP developed at NASA's Marshall Space Flight Center: (1) cooling tower, (2) vapor-compression refrigeration system, and (3) vapor-expansion power generation system. These systems are widely used across engineering disciplines in a variety of energy systems, and these models expand the capabilities and the use of GFSSP to include fluids and features that are not part of its present set of provided examples. GFSSP provides pressure, temperature, and species concentrations at designated locations, or nodes, within a fluid network based on a finite volume formulation of thermodynamics and conservation laws. This paper describes the theoretical basis for the construction of the models, their implementation in the current GFSSP modeling system, and a brief evaluation of the usefulness of the model results, as well as their applicability toward a broader spectrum of analytical problems in both university teaching and engineering research.

Vapor-fed bio-hybrid fuel cell.

PubMed

Benyamin, Marcus S; Jahnke, Justin P; Mackie, David M

2017-01-01

Concentration and purification of ethanol and other biofuels from fermentations are energy-intensive processes, with amplified costs at smaller scales. To circumvent the need for these processes, and to potentially reduce transportation costs as well, we have previously investigated bio-hybrid fuel cells (FCs), in which a fermentation and FC are closely coupled. However, long-term operation requires strictly preventing the fermentation and FC from harming each other. We introduce here the concept of the vapor-fed bio-hybrid FC as a means of continuously extracting power from ongoing fermentations at ambient conditions. By bubbling a carrier gas (N 2 ) through a yeast fermentation and then through a direct ethanol FC, we protect the FC anode from the catalyst poisons in the fermentation (which are non-volatile), and also protect the yeast from harmful FC products (notably acetic acid) and from build-up of ethanol. Since vapor-fed direct ethanol FCs at ambient conditions have never been systematically characterized (in contrast to vapor-fed direct methanol FCs), we first assess the effects on output power and conversion efficiency of ethanol concentration, vapor flow rate, and FC voltage. The results fit a continuous stirred-tank reactor model. Over a wide range of ethanol partial pressures (2-8 mmHg), power densities are comparable to those for liquid-fed direct ethanol FCs at the same temperature, with power densities >2 mW/cm 2 obtained. We then demonstrate the continuous operation of a vapor-fed bio-hybrid FC with fermentation for 5 months, with no indication of performance degradation due to poisoning (of either the FC or the fermentation). It is further shown that the system is stable, recovering quickly from disturbances or from interruptions in maintenance. The vapor-fed bio-hybrid FC enables extraction of power from dilute bio-ethanol streams without costly concentration and purification steps. The concept should be scalable to both large and small

Corrosion Studies in Support of Medium Power Lead Alloy Cooled Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eric Loewen; Ronald Ballinger; Jeongyoun Lim

2004-09-01

The performance of structural materials in lead or lead-bismuth eutectic (LBE) systems is evaluated. The materials evaluated included refractory metals (W, Mo, and Ta), several U.S. steels [austenitic steel (316L), carbon steels (F-22, Fe-Si), ferritic/martensitic steels (HT-9 and 410)], and several experimental Fe-Si-Cr alloys that were expected to demonstrate corrosion resistance. The materials were exposed in either an LBE rotating electrode or a dynamic corrosion cell for periods from 100 to 1000 h at temperatures of 400, 500, 600, and 700°C, depending on material and exposure location. Weight change and optical scanning electron microscopy or X-ray analysis of the specimenmore » were used to characterize oxide film thickness, corrosion depth, microstructure, and composition changes. The results of corrosion tests validate the excellent resistance of refractory metals (W, Ta, and Mo) to LBE corrosion. The tests conducted with stainless steels (410, 316L, and HT-9) produced mass transfer of elements (e.g., Ni and Cr) into the LBE, resulting in degradation of the material. With Fe-Si alloys a Si-rich layer (as SiO2) is formed on the surface during exposure to LBE from the selective dissolution of Fe.« less

Corrosion Studies in Support of Medium-Power Lead-Alloy-Cooled Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loewen, Eric P.; Ballinger, Ronald G.; Lim, Jeongyoun

2004-09-15

The performance of structural materials in lead or lead-bismuth eutectic (LBE) systems is evaluated. The materials evaluated included refractory metals (W, Mo, and Ta), several U.S. steels [austenitic steel (316L), carbon steels (F-22, Fe-Si), ferritic/martensitic steels (HT-9 and 410)], and several experimental Fe-Si-Cr alloys that were expected to demonstrate corrosion resistance. The materials were exposed in either an LBE rotating electrode or a dynamic corrosion cell for periods from 100 to 1000 h at temperatures of 400, 500, 600, and 700 deg. C, depending on material and exposure location. Weight change and optical scanning electron microscopy or X-ray analysis ofmore » the specimen were used to characterize oxide film thickness, corrosion depth, microstructure, and composition changes. The results of corrosion tests validate the excellent resistance of refractory metals (W, Ta, and Mo) to LBE corrosion. The tests conducted with stainless steels (410, 316L, and HT-9) produced mass transfer of elements (e.g., Ni and Cr) into the LBE, resulting in degradation of the material. With Fe-Si alloys a Si-rich layer (as SiO{sub 2}) is formed on the surface during exposure to LBE from the selective dissolution of Fe.« less

To cool, but not too cool: that is the question--immersion cooling for hyperthermia.

PubMed

Taylor, Nigel A S; Caldwell, Joanne N; Van den Heuvel, Anne M J; Patterson, Mark J

2008-11-01

Patient cooling time can impact upon the prognosis of heat illness. Although ice-cold-water immersion will rapidly extract heat, access to ice or cold water may be limited in hot climates. Indeed, some have concerns regarding the sudden cold-water immersion of hyperthermic individuals, whereas others believe that cutaneous vasoconstriction may reduce convective heat transfer from the core. It was hypothesized that warmer immersion temperatures, which induce less powerful vasoconstriction, may still facilitate rapid cooling in hyperthermic individuals. Eight males participated in three trials and were heated to an esophageal temperature of 39.5 degrees C by exercising in the heat (36 degrees C, 50% relative humidity) while wearing a water-perfusion garment (40 degrees C). Subjects were cooled using each of the following methods: air (20-22 degrees C), cold-water immersion (14 degrees C), and temperate-water immersion (26 degrees C). The time to reach an esophageal temperature of 37.5 degrees C averaged 22.81 min (air), 2.16 min (cold), and 2.91 min (temperate). Whereas each of the between-trial comparisons was statistically significant (P < 0.05), cooling in temperate water took only marginally longer than that in cold water, and one cannot imagine that the 45-s cooling time difference would have any meaningful physiological or clinical implications. It is assumed that this rapid heat loss was due to a less powerful peripheral vasoconstrictor response, with central heat being more rapidly transported to the skin surface for dissipation. Although the core-to-water thermal gradient was much smaller with temperate-water cooling, greater skin and deeper tissue blood flows would support a superior convective heat delivery. Thus, a sustained physiological mechanism (blood flow) appears to have countered a less powerful thermal gradient, resulting in clinically insignificant differences in heat extraction between the cold and temperate cooling trials.

Contribution for Iron Vapor and Radiation Distribution Affected by Current Frequency of Pulsed Arc

NASA Astrophysics Data System (ADS)

Shimokura, Takuya; Mori, Yusuke; Iwao, Toru; Yumoto, Motoshige

Pulsed GTA welding has been used for improvement of stability, weld speed, and heat input control. However, the temperature and radiation power of the pulsed arc have not been elucidated. Furthermore, arc contamination by metal vapor changes the arc characteristics, e.g. by increasing radiation power. In this case, the metal vapor in pulsed GTA welding changes the distribution of temperature and radiation power as a function of time. This paper presents the relation between metal vapor and radiation power at different pulse frequencies. We calculate the Fe vapor distribution of the pulsed current. Results show that the Fe vapor is transported at fast arc velocity during the peak current period. During the base current period, the Fe vapor concentration is low and distribution is diffuse. The transition of Fe vapor distribution does not follow the pulsed current; the radiation power density distribution differs for high frequencies and low frequencies. In addition, the Fe vapor and radiation distribution are affected by the pulsed arc current frequency.

Power generation by thermally assisted electroluminescence: like optical cooling, but different

NASA Astrophysics Data System (ADS)

Buckner, Benjamin D.; Heeg, Bauke

2008-02-01

Thermally assisted electro-luminescence may provide a means to convert heat into electricity. In this process, radiation from a hot light-emitting diode (LED) is converted to electricity by a photovoltaic (PV) cell, which is termed thermophotonics. Novel analytical solutions to the equations governing such a system show that this system combines physical characteristics of thermophotovoltaics (TPV) and the inverse process of laser cooling. The flexibility of having both adjustable bias and load parameters may allow an optimized power generation system based on this concept to exceed the power throughput and efficiency of TPV systems. Such devices could function as efficient solar thermal, waste heat, and fuel-based generators.

CVD SiC deformable mirror with monolithic cooling channels.

PubMed

Ahn, Kyohoon; Rhee, Hyug-Gyo; Yang, Ho-Soon; Kihm, Hagyong

2018-04-16

We propose a novel deformable mirror (DM) for adaptive optics in high power laser applications. The mirror is made of a Silicon carbide (SiC) faceplate, and cooling channels are embedded monolithically inside the faceplate with the chemical vapor desposition (CVD) method. The faceplate is 200 mm in diameter and 3 mm in thickness, and is actuated by 137 stack-type piezoelectric transducers arranged in a square grid. We also propose a new actuator influence function optimized for modelling our DM, which has a relatively stiffer faceplate and a higher coupling ratio compared with other DMs having thin faceplates. The cooling capability and optical performance of the DM are verified by simulations and actual experiments with a heat source. The DM is proved to operate at 1 kHz without the coolant flow and 100 Hz with the coolant flow, and the residual errors after compensation are less than 30 nm rms (root-mean-square). This paper presents the design, fabrication, and optical performance of the CVD SiC DM.

Cooling circuit for and method of cooling a gas turbine bucket

DOEpatents

Jacala, Ariel C. P.

2002-01-01

A closed internal cooling circuit for a gas turbine bucket includes axial supply and return passages in the dovetail of the bucket. A first radial outward supply passage provides cooling medium to and along a passageway adjacent the leading edge and then through serpentine arranged passageways within the airfoil to a chamber adjacent the airfoil tip. A second radial passage crosses over the radial return passage for supplying cooling medium to and along a pair of passageways along the trailing edge of the airfoil section. The last passageway of the serpentine passageways and the pair of passageways communicate one with the other in the chamber for returning spent cooling medium radially inwardly along divided return passageways to the return passage. In this manner, both the leading and trailing edges are cooled using the highest pressure, lowest temperature cooling medium.

The development of a performance-enhancing additive for vapor-compression heat pumps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grzyll, L.R.; Scaringe, R.P.; Gottschlich, J.M.

1997-12-31

This paper describes the testing results of a vapor-compression heat pump operating with HFC-134a refrigerant and a performance-enhancing additive. Preliminary bench-top testing of this additive, when added to polyolester (POE) lubricant and HFC-134a refrigerant, showed surprising enhancements to system COP. To further investigate this finding, the authors designed and fabricated a vapor-compression heat pump test stand for the 3--5 ton range. The authors investigated the effect of different concentrations of this additive on various system performance parameters such as cooling capacity, compressor power requirement, pressure ratio, compressor pressure difference, compressor isentropic efficiency, refrigerant flow rate, and heat exchanger performance. Themore » authors investigated various heat source and heat sink conditions to simulate air-conditioning and heat pump operating conditions. To investigate the effect of this additive on compressor lubrication and life, the authors performed compressor life tests (with scroll and reciprocating compressors), and had lubrication wear tests performed with various concentrations of the additive in the POE lubricant.« less

AMTEC vapor-vapor series connected cells

NASA Technical Reports Server (NTRS)

Underwood, Mark L. (Inventor); Williams, Roger M. (Inventor); Ryan, Margaret A. (Inventor); Nakamura, Barbara J. (Inventor); Oconnor, Dennis E. (Inventor)

1995-01-01

An alkali metal thermoelectric converter (AMTEC) having a plurality of cells structurally connected in series to form a septum dividing a plenum into two chambers, and electrically connected in series, is provided with porous metal anodes and porous metal cathodes in the cells. The cells may be planar or annular, and in either case a metal alkali vapor at a high temperature is provided to the plenum through one chamber on one side of the wall and returned to a vapor boiler after condensation at a chamber on the other side of the wall in the plenum. If the cells are annular, a heating core may be placed along the axis of the stacked cells. This arrangement of series-connected cells allows efficient generation of power at high voltage and low current.

Modeling Convection of Water Vapor into the Mid-latitude Summer Stratosphere

NASA Astrophysics Data System (ADS)

Clapp, C.; Leroy, S. S.; Anderson, J. G.

2016-12-01

Water vapor in the upper troposphere and lower stratosphere (UTLS) from the tropics to the poles is important both radiatively and chemically. Water vapor is the most important greenhouse gas, and increases in water vapor concentrations in the UTLS lead to cooling at these levels and induce warming at the surface [Forster and Shine, 1999; 2002; Solomon et al., 2010]. Water vapor is also integral to stratospheric chemistry. It is the dominant source of OH in the lower stratosphere [Hanisco et al., 2001], and increases in water vapor concentrations promote stratospheric ozone loss by raising the reactivity of several key heterogeneous reactions as well as by promoting the growth of reactive surface area [Anderson et al., 2012; Carslaw et al., 1995; Carslaw et al., 1997; Drdla and Muller , 2012; Kirk-Davidoff et al., 1999; Shi et al., 2001]. However, the processes that control the distribution and phase of water in this region of the atmosphere are not well understood. This is especially true at mid-latitudes where several different dynamical mechanisms are capable of influencing UTLS water vapor concentrations. The contribution by deep convective storm systems that penetrate into the lower stratosphere is the least well understood and the least well represented in global models because of the small spatial scales and short time scales over which convection occurs. To address this issue, we have begun a modeling study to investigate the convective injection of water vapor from the troposphere into the stratosphere in the mid-latitudes. Fine-scale models have been previously used to simulate convection from the troposphere to the stratosphere [e.g., Homeyer et al., 2014]. Here we employ the Advanced Research Weather and Research Forecasting model (ARW) at 3-km resolution to resolve convection over the mid-western United States during August of 2013 including a storm system observed by SEAC4RS. We assess the transport of water vapor into the stratosphere over the model

78 FR 64029 - Cost-Benefit Analysis for Radwaste Systems for Light-Water-Cooled Nuclear Power Reactors

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-25

... NUCLEAR REGULATORY COMMISSION [NRC-2013-0237] Cost-Benefit Analysis for Radwaste Systems for Light... (RG) 1.110, ``Cost-Benefit Analysis for Radwaste Systems for Light-Water-Cooled Nuclear Power Reactors... components for light water nuclear power reactors. ADDRESSES: Please refer to Docket ID NRC-2013-0237 when...

Characterization of urania vaporization with transpiration coupled thermogravimetry

DOE PAGES

McMurray, J. W.

2015-12-05

Determining equilibrium vapor pressures of materials is made easier by transpiration measurements. However, the traditional technique involves condensing the volatiles entrained in a carrier gas outside of the hot measurement zone. One potential problem is deposition en route to a cooled collector. Thermogravimetric analysis (TGA) can be used to measure in situ mass loss due to vaporization and therefore obviate the need to analyze the entire gas train due to premature plating of vapor species. Therefore, a transpiration coupled TGA technique was used to determine equilibrium pressures of UO3 gas over fluorite structure UO2+x and U3O8 at T = (1573more » and 1773) K. Moreover, we compared to calculations from models and databases in the open literature. Our study gives clarity to the thermochemical data for UO3 gas and validates the mass loss transpiration method using thermogravimetry for determining equilibrium vapor pressures of non-stoichiometric oxides.« less

Power flattening on modified CANDLE small long life gas-cooled fast reactor

NASA Astrophysics Data System (ADS)

Monado, Fiber; Su'ud, Zaki; Waris, Abdul; Basar, Khairul; Ariani, Menik; Sekimoto, Hiroshi

2014-09-01

Gas-cooled Fast Reactor (GFR) is one of the candidates of next generation Nuclear Power Plants (NPPs) that expected to be operated commercially after 2030. In this research conceptual design study of long life 350 MWt GFR with natural uranium metallic fuel as fuel cycle input has been performed. Modified CANDLE burn-up strategy with first and second regions located near the last region (type B) has been applied. This reactor can be operated for 10 years without refuelling and fuel shuffling. Power peaking reduction is conducted by arranging the core radial direction into three regions with respectively uses fuel volume fraction 62.5%, 64% and 67.5%. The average power density in the modified core is about 82 Watt/cc and the power peaking factor decreased from 4.03 to 3.43.

Leading-Edge Votex-System Details Obtained on F-106B Aircraft Using a Rotating Vapor Screen and Surface Techniques

NASA Technical Reports Server (NTRS)

Lamar, John E.; Brandon, Jay; Stacy, Kathryn; Johnson, Thomas D., Jr.; Severance, Kurt; Childers, Brooks A.

1993-01-01

A flight research program to study the flow structure and separated-flow origins over an F-106B aircraft wing is described. The flight parameters presented include Mach numbers from 0.26 to 0.81, angles of attack from 8.5 deg to 22.5 deg, Reynolds numbers from 22.6 x 10(exp 6) to 57.3 x 10(exp 6) and load factors from 0.9 to 3.9 times the acceleration due to gravity. Techniques for vapor screens, image enhancement, photogrammetry, and computer graphics are integrated to analyze vortex-flow systems. Emphasis is placed on the development and application of the techniques. The spatial location of vortex cores and their tracks over the wing are derived from the analysis. Multiple vortices are observed and are likely attributed to small surface distortions in the wing leading-edge region. A major thrust is to correlate locations of reattachment lines obtained from the off-surface (vapor-screen) observations with those obtained from on-surface oil-flow patterns and pressure-port data. Applying vapor-screen image data to approximate reattachment lines is experimental, but depending on the angle of attack, the agreement with oil-flow results is generally good. Although surface pressure-port data are limited, the vapor-screen data indicate reattachment point occurrences consistent with the available data.

Development of Thermoelectric Power Generation and Peltier Cooling Properties of Materials for Thermoelectric Cryocooling Devices

DTIC Science & Technology

2015-05-12

method. AAMU would like to continue, given future research funding, with our new design for the thermoelectric and photovoltaic systems and hybrid...nanofabrication to develop nanostructured thermoelectric (TE) materials for application in high-efficiency thermoelectric power generators and solid...Distribution Unlimited Final Report: Development of Thermoelectric Power Generation and Peltier Cooling Properties of Materials for Thermoelectric

Carbon-Electrode-Tailored All-Inorganic Perovskite Solar Cells To Harvest Solar and Water-Vapor Energy.

PubMed

Duan, Jialong; Hu, Tianyu; Zhao, Yuanyuan; He, Benlin; Tang, Qunwei

2018-05-14

Moisture is the worst enemy for state-of-the-art perovskite solar cells (PSCs). However, the flowing water vapor within nanoporous carbonaceous materials can create potentials. Therefore, it is a challenge to integrate water vapor and solar energies into a single PSC device. We demonstrate herein all-inorganic cesium lead bromide (CsPbBr 3 ) solar cells tailored with carbon electrodes to simultaneously harvest solar and water-vapor energy. Upon interfacial modification and plasma treatment, the bifunctional PSCs yield a maximum power conversion efficiency up to 9.43 % under one sun irradiation according to photoelectric conversion principle and a power output of 0.158 μW with voltage of 0.35 V and current of 0.45 μA in 80 % relative humidity through the flowing potentials at the carbon/water interface. The initial efficiency is only reduced by 2 % on exposing the inorganic PSC with 80 % humidity over 40 days. The successful realization of physical proof-of-concept multi-energy integrated solar cells provides new opportunities of maximizing overall power output. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Use of Sage Water Vapor Data for Investigating Climate Change Issues

NASA Technical Reports Server (NTRS)

Rind, D.

2003-01-01

SAGE water vapor data has proven valuable for addressing several of the important issues in climate change research. It has been used to investigate how the upper troposphere water vapor responds to warming and convection, a key question in understanding the water vapor feedback to anthropogenic global warming. In the case of summer versus winter differences, SAGE results showed that the upper tropospheric relative humidity remained approximately constant; this result was in general agreement with how a GCM handled the seasonal difference, and gave credence to the argument that the GCM was not overestimating the water vapor feedback associated with convection. In addition, the convection-water vapor relationship was investigated further using SAGE water vapor and ISCCP cloud data. The results showed that upper tropospheric drying did appear to occur simultaneously with deep convective events in the tropics, only to be replaced by moistening a few hours later, associated (most likely) with the reevaporation of moisture from anvil clouds. The total effect was, again, a moistening of the upper troposphere associated with convection. Calculation of the actual trends in upper tropospheric moisture is a potential goal for SAGE data usage; trends calculated with radiosonde data, or instruments calibrated with radiosonde data have the problem of the effect of changing radiosonde instruments. SAGE data have in effect been used to compare different radiosondes through comparisons, and could continue to do so. SAGE 3 should also help clarify the absolute accuracy of SAGE retrievals in the troposphere. and its consequences. Model results show that water vapor increases can help explain the observations of stratospheric cooling, along with increasing C02 and ozone reduction. SAGE has been shown to provide trends similar to those of some other satellite and in situ retrievals, with increasing water vapor over time. However, SAGE is impacted by aerosol contamination which must be

Evaporative Cooling and Dehumidification Garment for Portable Life Support Systems

NASA Technical Reports Server (NTRS)

Izenson, Michael; Chen, Weibo; Bue, Grant

2013-01-01

This paper describes the design and development of an innovative thermal and humidity control system for future space suits. The system comprises an evaporation cooling and dehumidification garment (ECDG) and a lithium chloride absorber radiator (LCAR). The ECDG absorbs heat and water vapor from inside the suit pressure garment, while the LCAR rejects heat to space without venting water vapor. The ECDG is built from thin, flexible patches with coversheets made of non-porous, water-permeable membranes that -enclose arrays of vapor flow passages. Water vapor from inside the spacesuit diffuses across the water permeable membranes, enters the vapor flow channels, and then flows to the LCAR, thus dehumidifying the internal volume of the space suit pressure garment. Additional water evaporation inside the ECDG provides cooling for sensible heat loads. -The heat released from condensation and absorption in the LCAR is rejected to the environment by thermal radiation. We have assembled lightweight and flexible ECDG pouches from prototypical materials and measured their performance in a series of separate effects tests under well-controlled, prototypical conditions. Sweating hot plate tests at typical space suit pressures show that ECDG pouches can absorb over 60 W/ft of latent heat and 20 W/ft of sensible heat from the pressure garment environment. These results are in good agreement with the predictions of our analysis models.

Numerical analysis of heat and mass transfer for water recovery in an evaporative cooling tower

NASA Astrophysics Data System (ADS)

Lee, Hyunsub; Son, Gihun

2017-11-01

Numerical analysis is performed for water recovery in an evaporative cooling tower using a condensing heat exchanger, which consists of a humid air channel and an ambient dry air channel. The humid air including water vapor produced in an evaporative cooling tower is cooled by the ambient dry air so that the water vapor is condensed and recovered to the liquid water. The conservation equations of mass, momentum, energy and vapor concentration in each fluid region and the energy equation in a solid region are simultaneously solved with the heat and mass transfer boundary conditions coupled to the effect of condensation on the channel surface of humid air. The present computation demonstrates the condensed water film distribution on the humid air channel, which is caused by the vapor mass transfer between the humid air and the colder water film surface, which is coupled to the indirect heat exchange with the ambient air. Computations are carried out to predict water recovery rate in parallel, counter and cross-flow type heat exchangers. The effects of air flow rate and channel interval on the water recovery rate are quantified.

Microgravity Spray Cooling Research for High Powered Laser Applications

NASA Technical Reports Server (NTRS)

Zivich, Chad P.

2004-01-01

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

Principles of passive and active cooling of mirror-based hybrid systems employing liquid metals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anglart, Henryk

This paper presents principles of passive and active cooling that are suitable to mirrorbased hybrid, nuclear fission/fusion systems. It is shown that liquid metal lead-bismuth cooling of the mirror machine with 25 m height and 1.5 GW thermal power is feasible both in the active mode during the normal operation and in the passive mode after the reactor shutdown. In the active mode the achievable required pumping power can well be below 50 MW, whereas the passive mode provides enough coolant flow to keep the clad temperature below the damage limits.

Principles of passive and active cooling of mirror-based hybrid systems employing liquid metals

NASA Astrophysics Data System (ADS)

Anglart, Henryk

2012-06-01

This paper presents principles of passive and active cooling that are suitable to mirrorbased hybrid, nuclear fission/fusion systems. It is shown that liquid metal lead-bismuth cooling of the mirror machine with 25 m height and 1.5 GW thermal power is feasible both in the active mode during the normal operation and in the passive mode after the reactor shutdown. In the active mode the achievable required pumping power can well be below 50 MW, whereas the passive mode provides enough coolant flow to keep the clad temperature below the damage limits.

Cooled-Spool Piston Compressor

NASA Technical Reports Server (NTRS)

Morris, Brian G.

1994-01-01

Proposed cooled-spool piston compressor driven by hydraulic power and features internal cooling of piston by flowing hydraulic fluid to limit temperature of compressed gas. Provides sufficient cooling for higher compression ratios or reactive gases. Unlike conventional piston compressors, all parts of compressed gas lie at all times within relatively short distance of cooled surface so that gas cooled more effectively.

Large diameter lasing tube cooling arrangement

DOEpatents

Hall, Jerome P [Livermore, CA; Alger, Terry W [Tracy, CA; Anderson, Andrew T [Livermore, CA; Arnold, Phillip A [Livermore, CA

2004-05-18

A cooling structure (16) for use inside a ceramic cylindrical tube (11) of a metal vapor laser (10) to cool the plasma in the tube (11), the cooling structure (16) comprising a plurality of circular metal members (17, 31) and mounting members (18, 34) that position the metal members (17, 31) coaxially in the tube (11) to form an annular lasing volume, with the metal members (17, 31) being axially spaced from each other along the length of the tube (11) to prevent the metal members from shorting out the current flow through the plasma in the tube (11) and to provide spaces through which the heat from localized hot spots in the plasma may radiate to the other side of the tube (11).

Large Diameter Lasing Tube Cooling Arrangement

DOEpatents

Hall, Jerome P.; Alger, Terry W.; Anderson, Andrew T.; Arnold, Philip A.

2004-05-18

A cooling structure (16) for use inside a ceramic cylindrical tube (11) of a metal vapor laser (10) to cool the plasma in the tube (11), the cooling structure (16) comprising a plurality of circular metal members (17,31) and mounting members (18, 34) that position the metal members (17,31) coaxially in the tube (11) to form an annular lasing volume, with the metal members (17, 31) being axially spaced from each other along the length of the tube (11) to prevent the metal members from shorting out the current flow through the plasma in the tube (11) and to provide spaces through which the heat from localized hot spots in the plasma may radiate to the other side of the tube (11).

A COMPUTATIONAL AND EXPERIMENTAL STUDY OF METAL AND COVALENT ORGANIC FRAMEWORKS USED IN ADSORPTION COOLING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jenks, Jeromy WJ; TeGrotenhuis, Ward E.; Motkuri, Radha K.

2015-07-09

Metal-organic frameworks (MOFs) have recently attracted enormous interest over the past few years due to their potential applications in energy storage and gas separation. However, there have been few reports on MOFs for adsorption cooling applications. Adsorption cooling technology is an established alternative to mechanical vapor compression refrigeration systems. Adsorption cooling is an excellent alternative in industrial environments where waste heat is available. Applications also include hybrid systems, refrigeration, power-plant dry cooling, cryogenics, vehicular systems and building HVAC. Adsorption based cooling and refrigeration systems have several advantages including few moving parts and negligible power consumption. Key disadvantages include large thermalmore » mass, bulkiness, complex controls, and low COP (0.2-0.5). We explored the use of metal organic frameworks that have very high mass loading and relatively low heats of adsorption, with certain combinations of refrigerants to demonstrate a new type of highly efficient adsorption chiller. An adsorption chiller based on MOFs suggests that a thermally-driven COP>1 may be possible with these materials, which would represent a fundamental breakthrough in performance of adsorption chiller technology. Computational fluid dynamics combined with a system level lumped-parameter model have been used to project size and performance for chillers with a cooling capacity ranging from a few kW to several thousand kW. In addition, a cost model has been developed to project manufactured cost of entire systems. These systems rely on stacked micro/mini-scale architectures to enhance heat and mass transfer. Presented herein are computational and experimental results for hydrophyilic MOFs, fluorophilic MOFs and also flourophilic Covalent-organic frameworks (COFs).« less

Stability assessment of the chemical composition of the treated mining water used to replenish the cooling circuit in Jaworzno III Power Plant - Power Plant II

NASA Astrophysics Data System (ADS)

Karpiński, Marcin; Kmiecik, Ewa

2017-11-01

In Poland, electricity is still produced mainly in conventional power plants where fuel and water are materials necessary to generate the electricity. Even in modern power plants operating according to the principles of the sustainable development, this involves a high intake of water and considerable production of wastewater. This, in turn, necessi-tates the application of some technological solutions aimed at limiting the negative impact on the environment. The Jaworzno III Power Plant - Power Plant II is located in Jaworzno, Silesian Province, Poland. In order to minimise the negative impact on the surface water, the plant replenishes the cooling circuit with the mining water obtained from the closed-down Jan Kanty mine. The paper presents a stability assessment of the chemical composition of the treated mining water used to replenish the cooling circuit based on the data from 2007-2017.

Experimental study of efficiency of solar panel by phase change material cooling

NASA Astrophysics Data System (ADS)

Wei, Nicholas Tan Jian; Nan, Wong Jian; Guiping, Cheng

2017-07-01

The dependence of efficiency of photovoltaic panels on their temperature during operation is a major concern for developers and users. In this paper, a phase change material (PCM) cooling system was designed for a 60W mono-crystalline solar panel. Tealights candle was selected as the cooling medium. The solar irradiance was recorded using Kipp & Zonen CMP3 pyranometer and Meteon data logger. Temperature distribution on the surface of solar panel, output voltage and output current of solar panel were measured. The average irradiance throughout data collection was found to be 705W/m2 and highest irradiance was 1100 W/m2. The average solar panel temperature was 43.6°C and a maximum temperature of 53°C was at the center of solar panel. Results showed that average power output and efficiency of the solar panel were 44.4W and 15%, respectively. It was found that the higher the solar irradiance, the lower the efficiency of solar panel and the higher the temperature and power output of solar panel. This is due to the fact that high irradiance results in high power input and high solar panel temperature. But high PV panel temperature reduces its power output. Therefore, the increase of power input outweighs that of power output, which leads to the decrease of efficiency of solar panel with the increase of solar irradiance. Compared with solar panel without cooling, the power output and efficiency of solar panel did not increase with PCM cooling. It indicates that Tealights candle as PCM cooling is not efficient in improving the efficiency of solar panel in this study.

Environmental Problems Associated With Decommissioning The Chernobyl Nuclear Power Plant Cooling Pond

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farfan, E. B.; Jannik, G. T.; Marra, J. C.

2009-11-09

Decommissioning of nuclear power plants and other nuclear fuel cycle facilities has been an imperative issue lately. There exist significant experience and generally accepted recommendations on remediation of lands with residual radioactive contamination; however, there are hardly any such recommendations on remediation of cooling ponds that, in most cases, are fairly large water reservoirs. The literature only describes remediation of minor reservoirs containing radioactive silt (a complete closure followed by preservation) or small water reservoirs resulting in reestablishing natural water flows. Problems associated with remediation of river reservoirs resulting in flooding of vast agricultural areas also have been described. Inmore » addition, the severity of environmental and economic problems related to the remedial activities is shown to exceed any potential benefits of these activities. One of the large, highly contaminated water reservoirs that require either remediation or closure is Karachay Lake near the MAYAK Production Association in the Chelyabinsk Region of Russia where liquid radioactive waste had been deep well injected for a long period of time. Backfilling of Karachay Lake is currently in progress. It should be noted that secondary environmental problems associated with its closure are considered to be of less importance since sustaining Karachay Lake would have presented a much higher radiological risk. Another well-known highly contaminated water reservoir is the Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond, decommissioning of which is planned for the near future. This study summarizes the environmental problems associated with the ChNPP Cooling Pond decommissioning.« less

ENVIRONMENTAL PROBLEMS ASSOCIATED WITH DECOMMISSIONING THE CHERNOBYL NUCLEAR POWER PLANT COOLING POND

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farfan, E.

2009-09-30

Decommissioning of nuclear power plants and other nuclear fuel cycle facilities has been an imperative issue lately. There exist significant experience and generally accepted recommendations on remediation of lands with residual radioactive contamination; however, there are hardly any such recommendations on remediation of cooling ponds that, in most cases, are fairly large water reservoirs. The literature only describes remediation of minor reservoirs containing radioactive silt (a complete closure followed by preservation) or small water reservoirs resulting in reestablishing natural water flows. Problems associated with remediation of river reservoirs resulting in flooding of vast agricultural areas also have been described. Inmore » addition, the severity of environmental and economic problems related to the remedial activities is shown to exceed any potential benefits of these activities. One of the large, highly contaminated water reservoirs that require either remediation or closure is Karachay Lake near the MAYAK Production Association in the Chelyabinsk Region of Russia where liquid radioactive waste had been deep well injected for a long period of time. Backfilling of Karachay Lake is currently in progress. It should be noted that secondary environmental problems associated with its closure are considered to be of less importance since sustaining Karachay Lake would have presented a much higher radiological risk. Another well-known highly contaminated water reservoir is the Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond, decommissioning of which is planned for the near future. This study summarizes the environmental problems associated with the ChNPP Cooling Pond decommissioning.« less

Status report on the Small Secure Transportable Autonomous Reactor (SSTAR) /Lead-cooled Fast Reactor (LFR) and supporting research and development.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sienicki, J. J.; Moisseytsev, A.; Yang, W. S.

2008-06-23

This report provides an update on development of a pre-conceptual design for the Small Secure Transportable Autonomous Reactor (SSTAR) Lead-Cooled Fast Reactor (LFR) plant concept and supporting research and development activities. SSTAR is a small, 20 MWe (45 MWt), natural circulation, fast reactor plant for international deployment concept incorporating proliferation resistance for deployment in non-fuel cycle states and developing nations, fissile self-sufficiency for efficient utilization of uranium resources, autonomous load following making it suitable for small or immature grid applications, and a high degree of passive safety further supporting deployment in developing nations. In FY 2006, improvements have been mademore » at ANL to the pre-conceptual design of both the reactor system and the energy converter which incorporates a supercritical carbon dioxide Brayton cycle providing higher plant efficiency (44 %) and improved economic competitiveness. The supercritical CO2 Brayton cycle technology is also applicable to Sodium-Cooled Fast Reactors providing the same benefits. One key accomplishment has been the development of a control strategy for automatic control of the supercritical CO2 Brayton cycle in principle enabling autonomous load following over the full power range between nominal and essentially zero power. Under autonomous load following operation, the reactor core power adjusts itself to equal the heat removal from the reactor system to the power converter through the large reactivity feedback of the fast spectrum core without the need for motion of control rods, while the automatic control of the power converter matches the heat removal from the reactor to the grid load. The report includes early calculations for an international benchmarking problem for a LBE-cooled, nitride-fueled fast reactor core organized by the IAEA as part of a Coordinated Research Project on Small Reactors without Onsite Refueling; the calculations use the same

Performance analysis of radiation cooled dc transmission lines for high power space systems

NASA Technical Reports Server (NTRS)

Schwarze, G. E.

1985-01-01

As space power levels increase to meet mission objectives and also as the transmission distance between power source and load increases, the mass, volume, power loss, and operating voltage and temperature become important system design considerations. This analysis develops the dependence of the specific mass and percent power loss on hte power and voltage levels, transmission distance, operating temperature and conductor material properties. Only radiation cooling is considered since the transmission line is assumed to operate in a space environment. The results show that the limiting conditions for achieving low specific mass, percent power loss, and volume for a space-type dc transmission line are the permissible transmission voltage and operating temperature. Other means to achieve low specific mass include the judicious choice of conductor materials. The results of this analysis should be immediately applicable to power system trade-off studies including comparisons with ac transmission systems.

Coupling apparatus for a metal vapor laser

DOEpatents

Ball, D.G.; Miller, J.L.

1993-02-23

Coupling apparatus for a large bore metal vapor laser is disclosed. The coupling apparatus provides for coupling high voltage pulses (approximately 40 KV) to a metal vapor laser with a high repetition rate (approximately 5 KHz). The coupling apparatus utilizes existing thyratron circuits and provides suitable power input to a large bore metal vapor laser while maintaining satisfactory operating lifetimes for the existing thyratron circuits.

Coupling apparatus for a metal vapor laser

DOEpatents

Ball, Don G.; Miller, John L.

1993-01-01

Coupling apparatus for a large bore metal vapor laser is disclosed. The coupling apparatus provides for coupling high voltage pulses (approximately 40 KV) to a metal vapor laser with a high repetition rate (approximately 5 KHz). The coupling apparatus utilizes existing thyratron circuits and provides suitable power input to a large bore metal vapor laser while maintaining satisfactory operating lifetimes for the existing thyratron circuits.

Floating loop method for cooling integrated motors and inverters using hot liquid refrigerant

DOEpatents

Hsu, John S.; Ayers, Curtis W.; Coomer, Chester; Marlino, Laura D.

2007-03-20

A method for cooling vehicle components using the vehicle air conditioning system comprising the steps of: tapping the hot liquid refrigerant of said air conditioning system, flooding a heat exchanger in the vehicle component with said hot liquid refrigerant, evaporating said hot liquid refrigerant into hot vapor refrigerant using the heat from said vehicle component, and returning said hot vapor refrigerant to the hot vapor refrigerant line in said vehicle air conditioning system.

Design and optimization of the heat rejection system for a liquid cooled thermionic space nuclear reactor power system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moriarty, M.P.

1993-01-15

The heat transport subsystem for a liquid metal cooled thermionic space nuclear power system was modelled using algorithms developed in support of previous nuclear power system study programs, which date back to the SNAP-10A flight system. The model was used to define the optimum dimensions of the various components in the heat transport subsystem subjected to the constraints of minimizing mass and achieving a launchable package that did not require radiator deployment. The resulting design provides for the safe and reliable cooling of the nuclear reactor in a proven lightweight design.

Design and optimization of the heat rejection system for a liquid cooled thermionic space nuclear reactor power system

NASA Astrophysics Data System (ADS)

Moriarty, Michael P.

1993-01-01

The heat transport subsystem for a liquid metal cooled thermionic space nuclear power system was modelled using algorithms developed in support of previous nuclear power system study programs, which date back to the SNAP-10A flight system. The model was used to define the optimum dimensions of the various components in the heat transport subsystem subjected to the constraints of minimizing mass and achieving a launchable package that did not require radiator deployment. The resulting design provides for the safe and reliable cooling of the nuclear reactor in a proven lightweight design.

Study of using microfiltration and reverse osmosis membrane technologies for reclaiming cooling water in the power industry.

PubMed

Li, J; Xu, Z Y; An, H G; Liu, L Q

2007-07-01

A study of using dual membrane technologies, microfiltration (MF) and reverse osmosis (RO), for reclaiming blowdown of the cooling tower was conducted at ZJK power plant, Hebei province, China. The study shows that the combined MF-RO system can effectively reduce water consumption in the power industry. The results indicate that MF process is capable of producing a filtrate suitable for RO treatment and achieving a silt density index (SDI) less than 2, turbidity of 0.2 NTU. The water quality of RO effluent is very good with an average conductivity of about 40 micros/cm and rejection of 98%. The product water is suitable for injection into the cooling tower to counteract with cooling water intrusion. After adopting this system, water-saving effectiveness as expressed in terms of cycles of concentration could be increased from 2.5-2.8 times to 5 times.

Passivation of Flexible YBCO Superconducting Current Lead With Amorphous SiO2 Layer

NASA Technical Reports Server (NTRS)

Johannes, Daniel; Webber, Robert

2013-01-01

Adiabatic demagnetization refrigerators (ADR) are operated in space to cool detectors of cosmic radiation to a few 10s of mK. A key element of the ADR is a superconducting magnet operating at about 0.3 K that is continually energized and de-energized in synchronism with a thermal switch, such that a piece of paramagnetic salt is alternately warm in a high magnetic field and cold in zero magnetic field. This causes the salt pill or refrigerant to cool, and it is able to suck heat from an object, e.g., the sensor, to be cooled. Current has to be fed into and out of the magnets from a dissipative power supply at the ambient temperature of the spacecraft. The current leads that link the magnets to the power supply inevitably conduct a significant amount of heat into the colder regions of the supporting cryostat, resulting in the need for larger, heavier, and more powerful supporting refrigerators. The aim of this project was to design and construct high-temperature superconductor (HTS) leads from YBCO (yttrium barium copper oxide) composite conductors to reduce the heat load significantly in the temperature regime below the critical temperature of YBCO. The magnet lead does not have to support current in the event that the YBCO ceases to be superconducting. Cus - tomarily, a normal metal conductor in parallel with the YBCO is a necessary part of the lead structure to allow for this upset condition; however, for this application, the normal metal can be dispensed with. Amorphous silicon dioxide is deposited directly onto the surface of YBCO, which resides on a flexible substrate. The silicon dioxide protects the YBCO from chemically reacting with atmospheric water and carbon dioxide, thus preserving the superconducting properties of the YBCO. The customary protective coating for flexible YBCO conductors is silver or a silver/gold alloy, which conducts heat many orders of magnitude better than SiO2 and so limits the use of such a composite conductor for passing current

Molecular dynamic approach to the study of the intense heat and mass transfer processes on the vapor-liquid interface

NASA Astrophysics Data System (ADS)

Levashov, V. Yu; Kamenov, P. K.

2017-10-01

The paper is devoted to research of the heat and mass transfer processes on the vapor-liquid interface. These processes can be realized for example at metal tempering, accidents at nuclear power stations, followed by the release of the corium into the heat carrier, getting hot magma into the water during volcanic eruptions and other. In all these examples the vapor film can arise on the heated body surface. In this paper the vapor film formation process will be considered with help of molecular dynamics simulation methods. The main attention during this process modeling will be focused on the subject of the fluid and vapor interactions with the heater surface. Another direction of this work is to study of the processes inside the droplet that may take place as result of impact of the high-power laser radiation. Such impact can lead to intensive evaporation and explosive destruction of the droplet. At that the duration of heat and mass transfer processes in droplet substance is tens of femtoseconds. Thus, the methods of molecular dynamics simulation can give the possibilities describe the heat and mass transfer processes in the droplet and the vapor phase formation.

Preliminary characterization of a water vaporizer for resistojet applications

NASA Technical Reports Server (NTRS)

Morren, W. Earl

1992-01-01

A series of tests was conducted to explore the characteristics of a water vaporizer intended for application to resistojet propulsion systems. The objectives of these tests were to (1) observe the effect of orientation with respect to gravity on vaporizer stability, (2) characterize vaporizer efficiency and outlet conditions over a range of flow rates, and (3) measure the thrust performance of a vaporizer/resistojet thruster assembly. A laboratory model of a forced-flow, once-through water vaporizer employing a porous heat exchange medium was built and characterized over a range of flow rates and power levels of interest for application to water resistojets. In a test during which the vaporizer was rotated about a horizontal axis normal to its own axis, the outlet temperature and mass flow rate through the vaporizer remained steady. Throttlability to 30 percent of the maximum flow rate tested was demonstrated. The measured thermal efficiency of the vaporizer was near 0.9 for all tests. The water vaporizer was integrated with an engineering model multipropellant resistojet. Performance of the vaporizer/thruster assembly was measured over a narrow range of operating conditions. The maximum specific impulse measured was 234 s at a mass flow rate and specific power level (vaporizer and thruster combined) of 154 x 10(exp-6)kg/s and 6.8 MJ/kg, respectively.

Design and simulation of liquid cooled system for power battery of PHEV

NASA Astrophysics Data System (ADS)

Wang, Jianpeng; Xu, Haijun; Xu, Xiaojun; Pan, Cunyun

2017-09-01

Various battery chemistries have different responses to failure, but the most common failure mode of a cell under abusive conditions is the generation of heat and gas. To prevent battery thermal abuse, a battery thermal management system is essential. An excellent design of battery thermal management system can ensure that the battery is working at a suitable temperature and keeps the battery temperature diffenence at 2-3 °C. This paper presents a thermal-elcetric coupling model for a 37Ah lithium battery using AMESim. A liquid cooled system of hybrid electric vehicle power battery is designed to control the battery temperature.A liquid cooled model of thermal management system is built using AMESim, the simulation results showed that the temperature difference within 3°C of cell in the pack.

PROCESS FOR COOLING A NUCLEAR REACTOR

DOEpatents

Borst, L.B.

1962-12-11

This patent relates to the operation of a reactor cooled by liquid sulfur dioxide. According to the invention the pressure on the sulfur dioxide in the reactor is maintained at least at the critical pressure of the sulfur dioxide. Heating the sulfur dioxide to its critical temperature results in vaporization of the sulfur dioxide without boiling. (AEC)

A novel membrane device for the removal of water vapor and water droplets from air

NASA Technical Reports Server (NTRS)

Ray, Rod; Newbold, David D.; Mccray, Scott B.; Friesen, Dwayne T.; Kliss, Mark

1992-01-01

One of the key challenges facing NASA engineers is the development of systems for separating liquids and gases in microgravity environments. In this paper, a novel membrane-based phase separator is described. This device, known as a water recovery heat exchanger (WRHEX), overcomes the inherent deficiencies of current phase-separation technology. Specifically, the WRHEX cools and removes water vapor or water droplets from feed-air streams without the use of a vacuum or centrifugal force. As is shown in this paper, only a low-power air blower and a small stream of recirculated cool water is required for WRHEX operation. This paper presents the results of tests using this novel membrane device over a wide range of operating conditions. The data show that the WRHEX produces a dry air stream containing no entrained or liquid water - even when the feed air contains water droplets or mist. An analysis of the operation of the WRHEX is presented.

Investigation of light source and scattering medium related to vapor-screen flow visualization in a supersonic wind tunnel

NASA Technical Reports Server (NTRS)

Snow, W. L.; Morris, O. A.

1984-01-01

Methods for increasing the radiant in light sheets used for vapor screen set-ups were investigated. Both high-pressure mercury arc lamps and lasers were considered. Pulsed operation of the air-cooled 1-kW lamps increased the light output but decreased reliability. An ellipsoidal mirror improved the output of the air-cooled lamps by concentrating the light but increased the complexity of the housing. Water-cooled-4-kW lamps coupled with high-aperture Fresnel lenses provided reasonable improvements over the air-cooled lamps. Fanned laser beams measurements of scattered light versus dew point made in conjunction with successful attempts to control the fluid injection. A number of smoke generators are described and test results comparing smoke and vapor screens are shown. Finally, one test included a periscope system to relay the image to a camera outside the flow.

Computational Simulation of a Water-Cooled Heat Pump

NASA Technical Reports Server (NTRS)

Bozarth, Duane

2008-01-01

A Fortran-language computer program for simulating the operation of a water-cooled vapor-compression heat pump in any orientation with respect to gravity has been developed by modifying a prior general-purpose heat-pump design code used at Oak Ridge National Laboratory (ORNL).

Effect of makeup water properties on the condenser fouling in power planr cooling system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Safari, I.; Walker, M.; Abbasian, J.

2011-01-01

The thermoelectric power industry in the U.S. uses a large amount of fresh water. As available freshwater for use in thermoelectric power production becomes increasingly limited, use of nontraditional water sources is of growing interest. Utilization of nontraditional water, in cooling systems increases the potential for mineral precipitation on heat exchanger surfaces. In that regard, predicting the accelerated rate of scaling and fouling in condenser is crucial to evaluate the condenser performance. To achieve this goal, water chemistry should be incorporated in cooling system modeling and simulation. This paper addresses the effects of various makeup water properties on the coolingmore » system, namely pH and aqueous speciation, both of which are important factors affecting the fouling rate in the main condenser. Detailed modeling of the volatile species desorption (i.e. CO{sub 2} and NH{sub 3}), the formation of scale in the recirculating system, and the relationship between water quality and the corresponding fouling rates is presented.« less

Cooling of High-Power LED Lamp Using a Commercial Paraffin Wax

NASA Astrophysics Data System (ADS)

Zmywaczyk, J.; Zbińkowski, P.; Smogór, H.; Olejnik, A.; Koniorczyk, P.

2017-03-01

Commercial paraffin wax used by Bolsius Nederland B.V. for manufacturing various kinds of candles was applied as a phase-change material (PCM) for cooling a 28 W high-power light emitting diode (LED) panel during its operation. The main problem arising during operation of an LED is thermal management. According to the manufacturer's datasheet specifications (BioSolution Ltd. www.biosolution.pl, the operating temperature range for the LED street lamp UL28W is (-30 {°}C) to (+40 {°}C). The object of the present study was an LED panel containing 28 pieces of high-power 1W LEDs connected in series (4 LEDs in each of the 7 rows) mounted on an aluminum plate of dimensions 80 mm by 135 mm. The tested aluminum plate was placed in a block made of aluminum with a hollow compartment containing Bolsius paraffin wax of density 914 kg\\cdot m^{-3} at room temperature. Temperatures were recorded using K-type thermocouples at selected locations of the tested LED panel for several values of the power supplied to it, while utilizing PCM and without it. As the manufacturer of Bolsius wax candles does not provide any data on the thermal properties of the material used, it was necessary to carry out micro-calorimetric research. Thermophysical properties of the paraffin wax such as the apparent specific heat, enthalpy of phase transition and temperature of phase change transition during heating and cooling were determined using the Netzsch DSC 214 Polyma. The Netzsch TG 209F3 Tarsus was used for TG/DTG measurements. DSC investigations revealed the following thermal transitions taking place during the first heating: solid-solid transition (onset 30.4 {°}C, peak at 40.9 {°}C), solid-liquid transition (onset 47.7 {°}C, peak at 54.9 {°}C, end at 58.3 {°}C), latent heat of energy storage 201 J\\cdot g^{-1}, apparent specific heat corresponding to peak at 41.5 {°}C (5.498 J\\cdot g^{-1}\\cdot K^{-1}). DTG investigations revealed that the decomposition of paraffin wax is a two

Contingency power for small turboshaft engines using water injection into turbine cooling air

NASA Technical Reports Server (NTRS)

Biesiadny, Thomas J.; Klann, Gary A.; Clark, David A.; Berger, Brett

1987-01-01

Because of one engine inoperative requirements, together with hot-gas reingestion and hot day, high altitude takeoff situations, power augmentation for multiengine rotorcraft has always been of critical interest. However, power augmentation using overtemperature at the turbine inlet will shorten turbine life unless a method of limiting thermal and mechanical stresses is found. A possible solution involves allowing the turbine inlet temperature to rise to augment power while injecting water into the turbine cooling air to limit hot-section metal temperatures. An experimental water injection device was installed in an engine and successfully tested. Although concern for unprotected subcomponents in the engine hot section prevented demonstration of the technique's maximum potential, it was still possible to demonstrate increases in power while maintaining nearly constant turbine rotor blade temperature.

An electrical model of vapor-anode, multitube AMTEC cells[Alkali Metal Thermal to Electric Conversion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tournier, J.M.; El-Genk, M.S.

1998-07-01

A two-dimensional electrical model of vapor-anode, multi-tube AMTEC cells was developed, which included four options of current collector configurations. Simulation results of several cells tested at AFRL showed that electrical losses in the current collector networks and the connecting leads were negligible. The polarization/concentration losses in the TiN electrodes were significant, amounting to 25%--50% of the cell theoretical power, while the contact and BASE ionic losses amounted to less than 16% of the cell theoretical power.

Hybrid gas-to-particle conversion and chemical vapor deposition for production of high-surface area films

NASA Astrophysics Data System (ADS)

Nguyen, Quynh Tan

A hybrid process, based upon gas-to-particle conversion and chemical vapor deposition, is presented as an alternative technique for producing porous films with the main advantages of solvent-free, low-substrate temperature operation. Starting from solid precursors, nanoparticles were produced in the vapor phase. Downstream of this reaction zone, these nanoparticles were collected via thermophoresis onto a cooled substrate forming a porous film. Initially, alumina (Al2O3) films were produced. Later, multi-component processing was explored by incorporating platinum (Pt) nanoparticles into the Al2O3 matrix leading to the production of Pt/Al 2O3 films by two routes: simultaneous precursor injection processing or by a layer-by-layer approach. In single component processing, the formation of nanoparticle aggregates was evident within the amorphous Al2O3 films. Aggregates, composed of these particles, are likely held together by relatively weak van der Waals forces leading to the observed poor physical cohesion. In multi-component processing, reasonable control of composition and distribution of species is possible with Pt nanoparticles appearing to be co-agglomerated with alumina. Deposited crystalline Pt nanoparticles may encourage the crystallization of the amorphous Al2O3. Finally, from chemisorption results, the produced sample appears to have potentially greater catalytic activity than a commercially available standard. A model is in development to study nanoparticle interactions with a gas and deposition occurring in stagnation flow onto the cooled horizontal substrate within the tubular reactor. Using velocity and temperature fields generated from numerical solutions to the Navier-Stokes and energy equations, particle trajectories were calculated from the summation of drag, gravitational, thermophoretic, and Brownian forces. In rectangular coordinates, cooling stage width to reactor diameter ratio, deposition stage temperature, and initial velocity were the

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

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

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

Portable vapor diffusion coefficient meter

DOEpatents

Ho, Clifford K [Albuquerque, NM

2007-06-12

An apparatus for measuring the effective vapor diffusion coefficient of a test vapor diffusing through a sample of porous media contained within a test chamber. A chemical sensor measures the time-varying concentration of vapor that has diffused a known distance through the porous media. A data processor contained within the apparatus compares the measured sensor data with analytical predictions of the response curve based on the transient diffusion equation using Fick's Law, iterating on the choice of an effective vapor diffusion coefficient until the difference between the predicted and measured curves is minimized. Optionally, a purge fluid can forced through the porous media, permitting the apparatus to also measure a gas-phase permeability. The apparatus can be made lightweight, self-powered, and portable for use in the field.

Airborne DOAS retrievals of methane, carbon dioxide, and water vapor concentrations at high spatial resolution: application to AVIRIS-NG

NASA Astrophysics Data System (ADS)

Thorpe, Andrew K.; Frankenberg, Christian; Thompson, David R.; Duren, Riley M.; Aubrey, Andrew D.; Bue, Brian D.; Green, Robert O.; Gerilowski, Konstantin; Krings, Thomas; Borchardt, Jakob; Kort, Eric A.; Sweeney, Colm; Conley, Stephen; Roberts, Dar A.; Dennison, Philip E.

2017-10-01

At local scales, emissions of methane and carbon dioxide are highly uncertain. Localized sources of both trace gases can create strong local gradients in its columnar abundance, which can be discerned using absorption spectroscopy at high spatial resolution. In a previous study, more than 250 methane plumes were observed in the San Juan Basin near Four Corners during April 2015 using the next-generation Airborne Visible/Infrared Imaging Spectrometer (AVIRIS-NG) and a linearized matched filter. For the first time, we apply the iterative maximum a posteriori differential optical absorption spectroscopy (IMAP-DOAS) method to AVIRIS-NG data and generate gas concentration maps for methane, carbon dioxide, and water vapor plumes. This demonstrates a comprehensive greenhouse gas monitoring capability that targets methane and carbon dioxide, the two dominant anthropogenic climate-forcing agents. Water vapor results indicate the ability of these retrievals to distinguish between methane and water vapor despite spectral interference in the shortwave infrared. We focus on selected cases from anthropogenic and natural sources, including emissions from mine ventilation shafts, a gas processing plant, tank, pipeline leak, and natural seep. In addition, carbon dioxide emissions were mapped from the flue-gas stacks of two coal-fired power plants and a water vapor plume was observed from the combined sources of cooling towers and cooling ponds. Observed plumes were consistent with known and suspected emission sources verified by the true color AVIRIS-NG scenes and higher-resolution Google Earth imagery. Real-time detection and geolocation of methane plumes by AVIRIS-NG provided unambiguous identification of individual emission source locations and communication to a ground team for rapid follow-up. This permitted verification of a number of methane emission sources using a thermal camera, including a tank and buried natural gas pipeline.

The influence and analysis of natural crosswind on cooling characteristics of the high level water collecting natural draft wet cooling tower

NASA Astrophysics Data System (ADS)

Ma, Libin; Ren, Jianxing

2018-01-01

Large capacity and super large capacity thermal power is becoming the main force of energy and power industry in our country. The performance of cooling tower is related to the water temperature of circulating water, which has an important influence on the efficiency of power plant. The natural draft counter flow wet cooling tower is the most widely used cooling tower type at present, and the high cooling tower is a new cooling tower based on the natural ventilation counter flow wet cooling tower. In this paper, for high cooling tower, the application background of high cooling tower is briefly explained, and then the structure principle of conventional cooling tower and high cooling tower are introduced, and the difference between them is simply compared. Then, the influence of crosswind on cooling performance of high cooling tower under different wind speeds is introduced in detail. Through analysis and research, wind speed, wind cooling had little impact on the performance of high cooling tower; wind velocity, wind will destroy the tower inside and outside air flow, reducing the cooling performance of high cooling tower; Wind speed, high cooling performance of cooling tower has increased, but still lower than the wind speed.

Studies of material and process compatibility in developing compact silicon vapor chambers

NASA Astrophysics Data System (ADS)

Cai, Qingjun; Bhunia, Avijit; Tsai, Chialun; Kendig, Martin W.; DeNatale, Jeffrey F.

2013-06-01

The performance and long-term reliability of a silicon vapor chamber (SVC) developed for thermal management of high-power electronics critically depend on compatibility of the component materials. A hermetically sealed SVC presented in this paper is composed of bulk silicon, glass-frit as a bonding agent, lead/tin solder as an interface sealant and a copper charging tube. These materials, in the presence of a water/vapor environment, may chemically react and release noncondensable gas (NCG), which can weaken structural strength and degrade the heat transfer performance with time. The present work reports detailed studies on chemical compatibility of the components and potential solutions to avoid the resulting thermal performance degradation. Silicon surface oxidation and purification of operating liquid are necessary steps to reduce performance degradation in the transient period. A lead-based solder with its low reflow temperature is found to be electrochemically stable in water/vapor environment. High glazing temperature solidifies molecular bonding in glass-frit and mitigates PbO precipitation. Numerous liquid flushes guarantee removal of chemical residual after the charging tube is soldered to SVC. With these improvements on the SVC material and process compatibility, high effective thermal conductivity and steady heat transfer performance are obtained.

Effect of Water Vapor, Temperature, and Rapid Annealing on Formamidinium Lead Triiodide Perovskite Crystallization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aguiar, Jeffery A.; Wozny, Sarah; Alkurd, Nooraldeen R.

Perovskite-based solar cells are one of the emerging candidates for radically lower cost photovoltaics. Herein, we report on the synthesis and crystallization of organic-inorganic formamidinium lead triiodide perovskite films under controlled atmospheric and environmental conditions. Using in situ (scanning) transmission electron microscopy, we make observations of the crystallization process of these materials in nitrogen and oxygen gas with and without the presence of water vapor. Complementary planar samples were also fabricated in the presence of water vapor and characterized by in situ X-ray diffraction. Direct observations of the material structure and final morphology indicate that the exposure to water vapormore » results in a porous film that is metastable, regardless of the presence of argon, nitrogen, or oxygen. However, the optimal crystallization temperature of 175 degrees C is unperturbed across conditions. Rapid modulation about the annealing temperature of 175 degrees C in +/-25 degrees C steps (150-200 degrees C) promotes crystallization and significantly improves the film morphology by overcoming the presence of impregnated water trapped in the material. Following this processing protocol, we demonstrate substantial growth to micron-size grains via observation inside of an environmentally controlled transmission electron microscope. Adapting this insight from our in situ microscopy, we are able to provide an informed materials protocol to control the structure and morphology of these organic-inorganic semiconductors, which is readily applicable to benchtop device growth strategies.« less

Effect of Water Vapor, Temperature, and Rapid Annealing on Formamidinium Lead Triiodide Perovskite Crystallization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aguiar, Jeffery A.; Wozny, Sarah; Alkurd, Nooraldeen R.

Perovskite-based solar cells are one of the emerging candidates for radically lower cost photovoltaics. Herein, we report on the synthesis and crystallization of organic-inorganic formamidinium lead triiodide perovskite films under controlled atmospheric and environmental conditions. Using in situ (scanning) transmission electron microscopy, we make observations of the crystallization process of these materials in nitrogen and oxygen gas with and without the presence of water vapor. Complementary planar samples were also fabricated in the presence of water vapor and characterized by in situ X-ray diffraction. Direct observations of the material structure and final morphology indicate that the exposure to water vapormore » results in a porous film that is metastable, regardless of the presence of argon, nitrogen, or oxygen. However, the optimal crystallization temperature of 175 °C is unperturbed across conditions. Rapid modulation about the annealing temperature of 175 °C in ±25 °C steps (150-200 °C) promotes crystallization and significantly improves the film morphology by overcoming the presence of impregnated water trapped in the material. Following this processing protocol, we demonstrate substantial growth to micron-size grains via observation inside of an environmentally controlled transmission electron microscope. Adapting this insight from our in situ microscopy, we are able to provide an informed materials protocol to control the structure and morphology of these organic-inorganic semiconductors, which is readily applicable to benchtop device growth strategies.« less

Effectiveness-weighted control of cooling system components

DOEpatents

Campbell, Levi A.; Chu, Richard C.; David, Milnes P.; Ellsworth Jr., Michael J.; Iyengar, Madhusudan K.; Schmidt, Roger R.; Simmons, Robert E.

2015-12-22

Energy efficient control of cooling system cooling of an electronic system is provided based, in part, on weighted cooling effectiveness of the components. The control includes automatically determining speed control settings for multiple adjustable cooling components of the cooling system. The automatically determining is based, at least in part, on weighted cooling effectiveness of the components of the cooling system, and the determining operates to limit power consumption of at least the cooling system, while ensuring that a target temperature associated with at least one of the cooling system or the electronic system is within a desired range by provisioning, based on the weighted cooling effectiveness, a desired target temperature change among the multiple adjustable cooling components of the cooling system. The provisioning includes provisioning applied power to the multiple adjustable cooling components via, at least in part, the determined control settings.

Methods and apparatus for cooling electronics

DOEpatents

Hall, Shawn Anthony; Kopcsay, Gerard Vincent

2014-12-02

Methods and apparatus are provided for choosing an energy-efficient coolant temperature for electronics by considering the temperature dependence of the electronics' power dissipation. This dependence is explicitly considered in selecting the coolant temperature T.sub.0 that is sent to the equipment. To minimize power consumption P.sub.Total for the entire system, where P.sub.Total=P.sub.0+P.sub.Cool is the sum of the electronic equipment's power consumption P.sub.0 plus the cooling equipment's power consumption P.sub.Cool, P.sub.Total is obtained experimentally, by measuring P.sub.0 and P.sub.Cool, as a function of three parameters: coolant temperature T.sub.0; weather-related temperature T.sub.3 that affects the performance of free-cooling equipment; and computational state C of the electronic equipment, which affects the temperature dependence of its power consumption. This experiment provides, for each possible combination of T.sub.3 and C, the value T.sub.0* of T.sub.0 that minimizes P.sub.Total. During operation, for any combination of T.sub.3 and C that occurs, the corresponding optimal coolant temperature T.sub.0* is selected, and the cooling equipment is commanded to produce it.

Seeded Physical Vapor Transport of Cadmium-Zinc Telluride Crystals: Growth and Characterization

NASA Technical Reports Server (NTRS)

Palosz, W.; George, M. A.; Collins, E. E.; Chen, K.-T.; Zhang, Y.; Burger, A.

1997-01-01

Crystals of Cd(1-x)Zn(x)Te with x = 0.2 and 40 g in weight were grown on monocrystalline cadmium-zinc telluride seeds by closed-ampoule physical vapor transport with or without excess (Cd + Zn) in the vapor phase. Two post-growth cool-down rates were used. The crystals were characterized using low temperature photoluminescence, atomic force microscopy, chemical etching, X-ray diffraction and electrical measurements. No formation of a second, ZnTe-rich phase was observed.

Multiplicities and thermal runaway of current leads for superconducting magnets

NASA Astrophysics Data System (ADS)

Krikkis, Rizos N.

2017-04-01

The multiple solutions of conduction and vapor cooled copper leads modeling current delivery to a superconducting magnet have been numerically calculated. Both ideal convection and convection with a finite heat transfer coefficient for an imposed coolant mass flow rate have been considered. Because of the nonlinearities introduced by the temperature dependent material properties, two solutions exist, one stable and one unstable regardless of the cooling method. The limit points separating the stable form the unstable steady states form the blow-up threshold beyond which, any further increase in the operating current results in a thermal runway. An interesting finding is that the multiplicity persists even when the cold end temperature is raised above the liquid nitrogen temperature. The effect of various parameters such as the residual resistivity ratio, the overcurrent and the variable conductor cross section on the bifurcation structure and their stabilization effect on the blow-up threshold is also evaluated.

Wet cooling towers: rule-of-thumb design and simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leeper, Stephen A.

1981-07-01

A survey of wet cooling tower literature was performed to develop a simplified method of cooling tower design and simulation for use in power plant cycle optimization. The theory of heat exchange in wet cooling towers is briefly summarized. The Merkel equation (the fundamental equation of heat transfer in wet cooling towers) is presented and discussed. The cooling tower fill constant (Ka) is defined and values derived. A rule-of-thumb method for the optimized design of cooling towers is presented. The rule-of-thumb design method provides information useful in power plant cycle optimization, including tower dimensions, water consumption rate, exit air temperature,more » power requirements and construction cost. In addition, a method for simulation of cooling tower performance at various operating conditions is presented. This information is also useful in power plant cycle evaluation. Using the information presented, it will be possible to incorporate wet cooling tower design and simulation into a procedure to evaluate and optimize power plant cycles.« less

Initiated chemical vapor deposition polymers for high peak-power laser targets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baxamusa, Salmaan H.; Lepro, Xavier; Lee, Tom

2016-12-05

Here, we report two examples of initiated chemical vapor deposition (iCVD) polymers being developed for use in laser targets for high peak-power laser systems. First, we show that iCVD poly(divinylbenzene) is more photo-oxidatively stable than the plasma polymers currently used in laser targets. Thick layers (10–12 μm) of this highly crosslinked polymer can be deposited with near-zero intrinsic film stress. Second, we show that iCVD epoxy polymers can be crosslinked after deposition to form thin adhesive layers for assembling precision laser targets. The bondlines can be made as thin as ~ 1 μm, approximately a factor of 2 thinner thanmore » achievable using viscous resin-based adhesives. These bonds can withstand downstream coining and stamping processes.« less

Advanced Heat Exchangers for Dry Cooling Systems, Phase II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fortini, Arthur J.; Horwath, Joseph

Dry cooling systems are an option for industrial and utility power plants that cannot obtain permits for cooling water or where cooling water is unavailable. Currently available dry cooling systems are more expensive and less efficient than wet cooling systems, so significant improvements in efficiency are needed to make them economically viable. Previous attempts at using foams as cooling fin materials for power generating systems have focused on high thermal conductivity graphite foams made via the Oak Ridge process. Because these materials have high flow restrictions and hence low permeability with respect to air flow, their internal volume and surfacemore » area were not effectively used. Consequently, they performed poorly and offered no advantage over aluminum fins. A foam with a more open structure would provide increased permeability, enable greater airflow through the bulk material, increase the rate of heat transfer, and enable the material to outperform traditional fin structures. In this project, Ultramet designed, fabricated, and tested low flow restriction, high-efficiency foam-based heat exchangers. Calculations based on existing thermal and hydraulic data for Ultramet’s high-performance open-cell foams indicated that 65-ppi (pores per linear inch) pyrolytic graphite foam with a relative density of 15 vol%, produced by chemical vapor infiltration (CVI), would have an effectiveness significantly greater than that of a state-of-the-art Hamon/Balcke-Durr aluminum fin system and greater than that of the POCO graphite foams previously tested for the DOE National Energy Technology Laboratory. Using the same chevron design, test setup, and run conditions as were used with the Hamon/Balcke-Durr fin system and the POCO foams, Ultramet tested graphite foams with air flow velocities of 0.07–3.2 m/sec and pressure drops of 0.03–9.7 inH2O. The best-performing graphite foam architectures had air velocities in excess of 2.5 m/sec when the pressure drop was

Thermal tests of large recirculation cooling installations for nuclear power plants

NASA Astrophysics Data System (ADS)

Balunov, B. F.; Lychakov, V. D.; Il'in, V. A.; Shcheglov, A. A.; Maslov, O. P.; Rasskazova, N. A.; Rakhimov, R. Z.; Boyarov, R. A.

2017-11-01

The article presents the results from thermal tests of some recirculation installations for cooling air in nuclear power plant premises, including the volume under the containment. The cooling effect in such installations is produced by pumping water through their heat-transfer tubes. Air from the cooled room is blown by a fan through a bundle of transversely finned tubes and is removed to the same room after having been cooled. The finning of tubes used in the tested installations was made of Grade 08Kh18N10T and Grade 08Kh18N10 stainless steels or Grade AD1 aluminum. Steel fins were attached to the tube over their entire length by means of high-frequency welding. Aluminum fins were extruded on a lathe from the external tube sheath into which a steel tube had preliminarily been placed. Although the fin extrusion operation was accompanied by pressing the sheath inner part to the steel tube, tight contact between them over the entire surface was not fully achieved. In view of this, the air gap's thermal resistance coefficient was introduced in calculating the heat transfer between the heat-transferring media. The air gap average thickness was determined from the test results taking into account the gap variation with temperature due to different linear expansion coefficients of steel and aluminum. These tests, which are part of the acceptance tests of the considered installations, were carried out at the NPO TsKTI test facility and were mainly aimed at checking if the obtained thermal characteristics were consistent with the values calculated according to the standard recommendations with introduction, if necessary, of modifications to those recommendations.

A Feasibility Study for Simultaneous Measurements of Water Vapor and Precipitation Parameters using a Three-frequency Radar

NASA Technical Reports Server (NTRS)

Meneghini, R.; Liao, L.; Tian, L.

2005-01-01

The radar return powers from a three-frequency radar, with center frequency at 22.235 GHz and upper and lower frequencies chosen with equal water vapor absorption coefficients, can be used to estimate water vapor density and parameters of the precipitation. A linear combination of differential measurements between the center and lower frequencies on one hand and the upper and lower frequencies on the other provide an estimate of differential water vapor absorption. The coupling between the precipitation and water vapor estimates is generally weak but increases with bandwidth and the amount of non-Rayleigh scattering of the hydrometeors. The coupling leads to biases in the estimates of water vapor absorption that are related primarily to the phase state and the median mass diameter of the hydrometeors. For a down-looking radar, path-averaged estimates of water vapor absorption are possible under rain-free as well as raining conditions by using the surface returns at the three frequencies. Simulations of the water vapor attenuation retrieval show that the largest source of error typically arises from the variance in the measured radar return powers. Although the error can be mitigated by a combination of a high pulse repetition frequency, pulse compression, and averaging in range and time, the radar receiver must be stable over the averaging period. For fractional bandwidths of 20% or less, the potential exists for simultaneous measurements at the three frequencies with a single antenna and transceiver, thereby significantly reducing the cost and mass of the system.

Vapor-Driven Propulsion of Catalytic Micromotors

NASA Astrophysics Data System (ADS)

Dong, Renfeng; Li, Jinxing; Rozen, Isaac; Ezhilan, Barath; Xu, Tailin; Christianson, Caleb; Gao, Wei; Saintillan, David; Ren, Biye; Wang, Joseph

2015-08-01

Chemically-powered micromotors offer exciting opportunities in diverse fields, including therapeutic delivery, environmental remediation, and nanoscale manufacturing. However, these nanovehicles require direct addition of high concentration of chemical fuel to the motor solution for their propulsion. We report the efficient vapor-powered propulsion of catalytic micromotors without direct addition of fuel to the micromotor solution. Diffusion of hydrazine vapor from the surrounding atmosphere into the sample solution is instead used to trigger rapid movement of iridium-gold Janus microsphere motors. Such operation creates a new type of remotely-triggered and powered catalytic micro/nanomotors that are responsive to their surrounding environment. This new propulsion mechanism is accompanied by unique phenomena, such as the distinct off-on response to the presence of fuel in the surrounding atmosphere, and spatio-temporal dependence of the motor speed borne out of the concentration gradient evolution within the motor solution. The relationship between the motor speed and the variables affecting the fuel concentration distribution is examined using a theoretical model for hydrazine transport, which is in turn used to explain the observed phenomena. The vapor-powered catalytic micro/nanomotors offer new opportunities in gas sensing, threat detection, and environmental monitoring, and open the door for a new class of environmentally-triggered micromotors.

Vapor-Driven Propulsion of Catalytic Micromotors

PubMed Central

Dong, Renfeng; Li, Jinxing; Rozen, Isaac; Ezhilan, Barath; Xu, Tailin; Christianson, Caleb; Gao, Wei; Saintillan, David; Ren, Biye; Wang, Joseph

2015-01-01

Chemically-powered micromotors offer exciting opportunities in diverse fields, including therapeutic delivery, environmental remediation, and nanoscale manufacturing. However, these nanovehicles require direct addition of high concentration of chemical fuel to the motor solution for their propulsion. We report the efficient vapor-powered propulsion of catalytic micromotors without direct addition of fuel to the micromotor solution. Diffusion of hydrazine vapor from the surrounding atmosphere into the sample solution is instead used to trigger rapid movement of iridium-gold Janus microsphere motors. Such operation creates a new type of remotely-triggered and powered catalytic micro/nanomotors that are responsive to their surrounding environment. This new propulsion mechanism is accompanied by unique phenomena, such as the distinct off-on response to the presence of fuel in the surrounding atmosphere, and spatio-temporal dependence of the motor speed borne out of the concentration gradient evolution within the motor solution. The relationship between the motor speed and the variables affecting the fuel concentration distribution is examined using a theoretical model for hydrazine transport, which is in turn used to explain the observed phenomena. The vapor-powered catalytic micro/nanomotors offer new opportunities in gas sensing, threat detection, and environmental monitoring, and open the door for a new class of environmentally-triggered micromotors. PMID:26285032

Laser-induced rotation and cooling of a trapped microgyroscope in vacuum

PubMed Central

Arita, Yoshihiko; Mazilu, Michael; Dholakia, Kishan

2013-01-01

Quantum state preparation of mesoscopic objects is a powerful playground for the elucidation of many physical principles. The field of cavity optomechanics aims to create these states through laser cooling and by minimizing state decoherence. Here we demonstrate simultaneous optical trapping and rotation of a birefringent microparticle in vacuum using a circularly polarized trapping laser beam—a microgyroscope. We show stable rotation rates up to 5 MHz. Coupling between the rotational and translational degrees of freedom of the trapped microgyroscope leads to the observation of positional stabilization in effect cooling the particle to 40 K. We attribute this cooling to the interaction between the gyroscopic directional stabilization and the optical trapping field. PMID:23982323

Retrofit device and method to improve humidity control of vapor compression cooling systems

DOEpatents

Roth, Robert Paul; Hahn, David C.; Scaringe, Robert P.

2016-08-16

A method and device for improving moisture removal capacity of a vapor compression system is disclosed. The vapor compression system is started up with the evaporator blower initially set to a high speed. A relative humidity in a return air stream is measured with the evaporator blower operating at the high speed. If the measured humidity is above the predetermined high relative humidity value, the evaporator blower speed is reduced from the initially set high speed to the lowest possible speed. The device is a control board connected with the blower and uses a predetermined change in measured relative humidity to control the blower motor speed.

Purification and Crystal Growth of Lead Iodide by Physical Vapor Transport Method

NASA Technical Reports Server (NTRS)

Wright, G. W.; Cole, M.; Chen, Y.-F.; Chen, K.-T.; Chen, H.; Chattopadhyay, K.; Burger, A.

1998-01-01

Lead iodide (PbI2) is a layered compound semiconductor being developed as room temperature x- and gamma-ray detector. Compared to the more studied material, mercuric iodide, PbI2 has a higher melting temperature and no phase transition until liquid phase which are indications of better mechanical properties. In this study, the source material was purified by the zone-refining process, and the purest section was extracted from center of the the zone-refined ingot to be grown by physical vapor transport (PVT) method. The zone-refined material and as-grown crystals were characterized by optical microscopy and differential scanning calorimetry (DSC) to reveal the surface morphology, purity and stoichiometry. The results shows that both materials are near-stoichiometric composition, with the purity of the as-grown crystals higher than zone-refined materials. The resistivity of the as-grown crystal (10" Omega-cm) was derived from current-voltage (I-V) measurement, and is 10 times higher than the zone-refined materials. Detail results will be presented and discussed.

Active cooling of pulse compression diffraction gratings for high energy, high average power ultrafast lasers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alessi, David A.; Rosso, Paul A.; Nguyen, Hoang T.

Laser energy absorption and subsequent heat removal from diffraction gratings in chirped pulse compressors poses a significant challenge in high repetition rate, high peak power laser development. In order to understand the average power limitations, we have modeled the time-resolved thermo-mechanical properties of current and advanced diffraction gratings. We have also developed and demonstrated a technique of actively cooling Petawatt scale, gold compressor gratings to operate at 600W of average power - a 15x increase over the highest average power petawatt laser currently in operation. As a result, combining this technique with low absorption multilayer dielectric gratings developed in ourmore » group would enable pulse compressors for petawatt peak power lasers operating at average powers well above 40kW.« less

Active cooling of pulse compression diffraction gratings for high energy, high average power ultrafast lasers

DOE PAGES

Alessi, David A.; Rosso, Paul A.; Nguyen, Hoang T.; ...

2016-12-26

Laser energy absorption and subsequent heat removal from diffraction gratings in chirped pulse compressors poses a significant challenge in high repetition rate, high peak power laser development. In order to understand the average power limitations, we have modeled the time-resolved thermo-mechanical properties of current and advanced diffraction gratings. We have also developed and demonstrated a technique of actively cooling Petawatt scale, gold compressor gratings to operate at 600W of average power - a 15x increase over the highest average power petawatt laser currently in operation. As a result, combining this technique with low absorption multilayer dielectric gratings developed in ourmore » group would enable pulse compressors for petawatt peak power lasers operating at average powers well above 40kW.« less

Spectral diagnostics of a vapor-plasma plume produced during welding titanium with a high-power ytterbium fiber laser

NASA Astrophysics Data System (ADS)

Uspenskiy, S. A.; Petrovskiy, V. N.; Bykovskiy, D. P.; Mironov, V. D.; Prokopova, N. M.; Tret'yakov, E. V.

2015-03-01

This work is devoted to the research of welding plume during high power ytterbium fiber laser welding of a titanium alloy in the Ar shielding gas environment. High speed video observation of a vapor-plasma plume for visualization of processes occurring at laser welding was carried out. The coefficient of the inverse Bremsstrahlung absorption of laser radiation is calculated for a plasma welding plume by results of spectrometer researches. The conclusion deals with the impact of plasma on a high-power fiber laser radiation.

Hydronic radiant cooling: Overview and preliminary performance assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feustel, H.E.

1993-05-01

A significant amount of electrical energy used to cool non-residential buildings is drawn by the fans used to transport the cool air through the thermal distribution system. Hydronic systems reduce the amount of air transported through the building by separating ventilation and thermal conditioning. Due to the physical properties of water, hydronic distribution systems can transport a given amount of thermal energy using less than 5% of the otherwise necessary fan energy. This savings alone significantly reduces the energy consumption and especially the peak power requirement This survey clearly shows advantages for radiant cooling in combination with hydronic thermal distributionmore » systems in comparison with the All-Air Systems commonly used in California. The report describes a literature survey on the system's development, thermal comfort issues, and cooling performance. The cooling power potential and the cooling power requirement are investigated for several California climates. Peak-power requirement is compared for hydronic radiant cooling and conventional All-Air-Systems.« less

Hydronic radiant cooling: Overview and preliminary performance assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feustel, H.E.

1993-05-01

A significant amount of electrical energy used to cool non-residential buildings is drawn by the fans used to transport the cool air through the thermal distribution system. Hydronic systems reduce the amount of air transported through the building by separating ventilation and thermal conditioning. Due to the physical properties of water, hydronic distribution systems can transport a given amount of thermal energy using less than 5% of the otherwise necessary fan energy. This savings alone significantly reduces the energy consumption and especially the peak power requirement This survey clearly shows advantages for radiant cooling in combination with hydronic thermal distributionmore » systems in comparison with the All-Air Systems commonly used in California. The report describes a literature survey on the system`s development, thermal comfort issues, and cooling performance. The cooling power potential and the cooling power requirement are investigated for several California climates. Peak-power requirement is compared for hydronic radiant cooling and conventional All-Air-Systems.« less

Mixed refrigerant cycle with neon, hydrogen, and helium for cooling sc power transmission lines

NASA Astrophysics Data System (ADS)

Kloeppel, S.; Dittmar, N.; Haberstroh, Ch; Quack, H.

2017-02-01

The use of superconductors in very long power transmission lines requires a reliable and effective cooling. Since the use of cryocoolers does not appear feasible for very long distances, a cryogenic refrigeration cycle needs to be developed. For cooling superconducting cables based on MgB2 (T c = 39 K), liquid hydrogen (LH2) is the obvious cooling agent. For recooling LH2, one would need a refrigeration cycle providing temperatures at around 20 K. For this purpose, one could propose the use of a helium refrigeration cycle. But the very low molecular weight of helium restricts the use of turbo compressors, which limits the overall efficiency. In order to increase the molecular weight of the refrigerant a mixture of cryogens could be used, allowing the use of a turbo compressor. Temperatures below the triple point of neon are achieved by phase separation. This paper presents a possible layout of a refrigeration cycle utilizing a three component mixture of neon, hydrogen, and helium.

Combined refrigeration system with a liquid pre-cooling heat exchanger

DOEpatents

Gaul, Christopher J.

2003-07-01

A compressor-pump unit for use in a vapor-compression refrigeration system is provided. The compressor-pump unit comprises a driving device including a rotatable shaft. A compressor is coupled with a first portion of the shaft for compressing gaseous refrigerant within the vapor-compression refrigeration system. A liquid pump is coupled with a second portion of the shaft for receiving liquid refrigerant having a first pressure and for discharging the received liquid refrigerant at a second pressure with the second pressure being higher than the first pressure by a predetermined amount such that the discharged liquid refrigerant is subcooled. A pre-cooling circuit is connected to the liquid pump with the pre-cooling circuit being exposed to the gaseous refrigerant whereby the gaseous refrigerant absorbs heat from the liquid refrigerant, prior to the liquid refrigerant entering the liquid pump.

Advanced Atmospheric Water Vapor DIAL Detection System

NASA Technical Reports Server (NTRS)

Refaat, Tamer F.; Elsayed-Ali, Hani E.; DeYoung, Russell J. (Technical Monitor)

2000-01-01

Measurement of atmospheric water vapor is very important for understanding the Earth's climate and water cycle. The remote sensing Differential Absorption Lidar (DIAL) technique is a powerful method to perform such measurement from aircraft and space. This thesis describes a new advanced detection system, which incorporates major improvements regarding sensitivity and size. These improvements include a low noise advanced avalanche photodiode detector, a custom analog circuit, a 14-bit digitizer, a microcontroller for on board averaging and finally a fast computer interface. This thesis describes the design and validation of this new water vapor DIAL detection system which was integrated onto a small Printed Circuit Board (PCB) with minimal weight and power consumption. Comparing its measurements to an existing DIAL system for aerosol and water vapor profiling validated the detection system.

Advanced chip designs and novel cooling techniques for brightness scaling of industrial, high power diode laser bars

NASA Astrophysics Data System (ADS)

Heinemann, S.; McDougall, S. D.; Ryu, G.; Zhao, L.; Liu, X.; Holy, C.; Jiang, C.-L.; Modak, P.; Xiong, Y.; Vethake, T.; Strohmaier, S. G.; Schmidt, B.; Zimer, H.

2018-02-01

The advance of high power semiconductor diode laser technology is driven by the rapidly growing industrial laser market, with such high power solid state laser systems requiring ever more reliable diode sources with higher brightness and efficiency at lower cost. In this paper we report simulation and experimental data demonstrating most recent progress in high brightness semiconductor laser bars for industrial applications. The advancements are in three principle areas: vertical laser chip epitaxy design, lateral laser chip current injection control, and chip cooling technology. With such improvements, we demonstrate disk laser pump laser bars with output power over 250W with 60% efficiency at the operating current. Ion implantation was investigated for improved current confinement. Initial lifetime tests show excellent reliability. For direct diode applications <1 um smile and >96% polarization are additional requirements. Double sided cooling deploying hard solder and optimized laser design enable single emitter performance also for high fill factor bars and allow further power scaling to more than 350W with 65% peak efficiency with less than 8 degrees slow axis divergence and high polarization.

Novel thermal management system using boiling cooling for high-powered lithium-ion battery packs for hybrid electric vehicles

NASA Astrophysics Data System (ADS)

Al-Zareer, Maan; Dincer, Ibrahim; Rosen, Marc A.

2017-09-01

A thermal management system is necessary to control the operating temperature of the lithium ion batteries in battery packs for electrical and hybrid electrical vehicles. This paper proposes a new battery thermal management system based on one type of phase change material for the battery packs in hybrid electrical vehicles and develops a three dimensional electrochemical thermal model. The temperature distributions of the batteries are investigated under various operating conditions for comparative evaluations. The proposed system boils liquid propane to remove the heat generated by the batteries, and the propane vapor is used to cool the part of the battery that is not covered with liquid propane. The effect on the thermal behavior of the battery pack of the height of the liquid propane inside the battery pack, relative to the height of the battery, is analyzed. The results show that the propane based thermal management system provides good cooling control of the temperature of the batteries under high and continuous charge and discharge cycles at 7.5C.

Cooling characteristics of air cooled radial turbine blades

NASA Astrophysics Data System (ADS)

Sato, T.; Takeishi, K.; Matsuura, M.; Miyauchi, J.

The cooling design and the cooling characteristics of air cooled radial turbine wheels, which are designed for use with the gas generator turbine for the 400 horse power truck gas turbine engine, are presented. A high temperature and high speed test was performed under aerodynamically similar conditions to that of the prototype engine in order to confirm the metal temperature of the newly developed integrated casting wheels constructed of the superalloys INCO 713C. The test results compared with the analytical value, which was established on the basis of the results of the heat transfer test and the water flow test, are discussed.

Cooling of a sunspot

NASA Technical Reports Server (NTRS)

Boruta, N.

1977-01-01

The question of whether a perturbed photospheric area can grow into a region of reduced temperature resembling a sunspot is investigated by considering whether instabilities exist that can lead to a growing temperature change and corresponding magnetic-field concentration in some region of the photosphere. After showing that Alfven cooling can lead to these instabilities, the effect of a heat sink on the temperature development of a perturbed portion of the photosphere is studied. A simple form of Alfven-wave cooling is postulated, and computations are performed to determine whether growing modes exist for physically relevant boundary conditions. The results indicate that simple inhibition of convection does not give growing modes, but Alfven-wave production can result in cooling that leads to growing field concentration. It is concluded that since growing instabilities can occur with strong enough cooling, it is quite possible that energy loss through Alfven waves gives rise to a self-generating temperature change and sunspot formation.

Water Vapor Effects on Silica-Forming Ceramics

NASA Technical Reports Server (NTRS)

Opila, E. J.; Greenbauer-Seng, L. (Technical Monitor)

2000-01-01

Silica-forming ceramics such as SiC and Si3N4 are proposed for applications in combustion environments. These environments contain water vapor as a product of combustion. Oxidation of silica-formers is more rapid in water vapor than in oxygen. Parabolic oxidation rates increase with the water vapor partial pressure with a power law exponent value close to one. Molecular water vapor is therefore the mobile species in silica. Rapid oxidation rates and large amounts of gases generated during the oxidation reaction in high water vapor pressures may result in bubble formation in the silica and nonprotective scale formation. It is also shown that silica reacts with water vapor to form Si(OH)4(g). Silica volatility has been modeled using a laminar flow boundary layer controlled reaction equation. Silica volatility depends on the partial pressure of water vapor, the total pressure, and the gas velocity. Simultaneous oxidation and volatilization reactions have been modeled with paralinear kinetics.

External fuel vaporization study, phase 1

NASA Technical Reports Server (NTRS)

Szetela, E. J.; Chiappetta, L.

1980-01-01

A conceptual design study was conducted to devise and evaluate techniques for the external vaporization of fuel for use in an aircraft gas turbine with characteristics similar to the Energy Efficient Engine (E(3)). Three vaporizer concepts were selected and they were analyzed from the standpoint of fuel thermal stability, integration of the vaporizer system into the aircraft engine, engine and vaporizer dynamic response, startup and altitude restart, engine performance, control requirements, safety, and maintenance. One of the concepts was found to improve the performance of the baseline E(3) engine without seriously compromising engine startup and power change response. Increased maintenance is required because of the need for frequent pyrolytic cleaning of the surfaces in contact with hot fuel.

Flue Dust Agglomeration in the Secondary Lead Industry

NASA Astrophysics Data System (ADS)

Schwitzgebel, Klaus

1981-01-01

A secondary lead smelter produces several tons of bag-house dust a day. Appropriate handling of this dust is mandatory to meet the proposed OSHA and EPA workroom and ambient standards. Dust agglomeration proved a successful approach. Dusts with a high concentration of PbCl2, or compounds containing PbCl2 can be agglomerated at much lower temperatures than samples with low PbCl2 concentrations. The chlorine sources are polyvinyl chloride (PVC) battery plate separators. Since PVC is used in Europe to a much greater extent than in the U.S., the composition of feedstock must be considered in equipment selection at U.S. secondary smelters. The vapor pressure characteristics of PbCl2 favor its evaporation at blast furnace temperatures. Condensation occurs in the gas cooling system. Recycling of baghouse dust leads to a buildup of PbCl2 in the smelter. Its removal from the system is eventually necessary through leaching, if charges with a high PVC content are processed.

Spill-Resistant Alkali-Metal-Vapor Dispenser

NASA Technical Reports Server (NTRS)

Klipstein, William

2005-01-01

A spill-resistant vessel has been developed for dispensing an alkali-metal vapor. Vapors of alkali metals (most commonly, cesium or rubidium, both of which melt at temperatures slightly above room temperature) are needed for atomic frequency standards, experiments in spectroscopy, and experiments in laser cooling. Although the present spill-resistant alkali-metal dispenser was originally intended for use in the low-gravity environment of outer space, it can also be used in normal Earth gravitation: indeed, its utility as a vapor source was confirmed by use of cesium in a ground apparatus. The vessel is made of copper. It consists of an assembly of cylinders and flanges, shown in the figure. The uppermost cylinder is a fill tube. Initially, the vessel is evacuated, the alkali metal charge is distilled into the bottom of the vessel, and then the fill tube is pinched closed to form a vacuum seal. The innermost cylinder serves as the outlet for the vapor, yet prevents spilling by protruding above the surface of the alkali metal, no matter which way or how far the vessel is tilted. In the event (unlikely in normal Earth gravitation) that any drops of molten alkali metal have been shaken loose by vibration and are floating freely, a mesh cap on top of the inner cylinder prevents the drops from drifting out with the vapor. Liquid containment of the equivalent of 1.2 grams of cesium was confirmed for all orientations with rubbing alcohol in one of the prototypes later used with cesium.

On the use of tin?lithium alloys as breeder material for blankets of fusion power plants

NASA Astrophysics Data System (ADS)

Fütterer, M. A.; Aiello, G.; Barbier, F.; Giancarli, L.; Poitevin, Y.; Sardain, P.; Szczepanski, J.; Li Puma, A.; Ruvutuso, G.; Vella, G.

2000-12-01

Tin-lithium alloys have several attractive thermo-physical properties, in particular high thermal conductivity and heat capacity, that make them potentially interesting candidates for use in liquid metal blankets. This paper presents an evaluation of the advantages and drawbacks caused by the substitution of the currently employed alloy lead-lithium (Pb-17Li) by a suitable tin-lithium alloy: (i) for the European water-cooled Pb-17Li (WCLL) blanket concept with reduced activation ferritic-martensitic steel as the structural material; (ii) for the European self-cooled TAURO blanket with SiC f/SiC as the structural material. It was found that in none of these blankets Sn-Li alloys would lead to significant advantages, in particular due to the low tritium breeding capability. Only in forced convection cooled divertors with W-alloy structure, Sn-Li alloys would be slightly more favorable. It is concluded that Sn-Li alloys are only advantageous in free surface cooled reactor internals, as this would make maximum use of the principal advantage of Sn-Li, i.e., the low vapor pressure.

Thermoelectrics in Coulomb-coupled quantum dots: Cotunneling and energy-dependent lead couplings

NASA Astrophysics Data System (ADS)

Walldorf, Nicklas; Jauho, Antti-Pekka; Kaasbjerg, Kristen

2017-09-01

We study thermoelectric effects in Coulomb-coupled quantum-dot (CCQD) systems beyond lowest-order tunneling processes and the often applied wide-band approximation. To this end, we present a master-equation (ME) approach based on a perturbative T -matrix calculation of the charge and heat tunneling rates and transport currents. Applying the method to transport through a noninteracting single-level QD, we demonstrate excellent agreement with the Landauer-Büttiker theory when higher-order (cotunneling) processes are included in the ME. Next, we study the effect of cotunneling and energy-dependent lead couplings on the heat currents in a system of two CCQDs. We find that cotunneling processes (i) can dominate the off-resonant heat currents at low temperature and bias compared to the interdot interaction, and (ii) give rise to a pronounced reduction of the cooling power achievable with the recently demonstrated Maxwell's demon cooling mechanism. Furthermore, we demonstrate that the cooling power can be boosted significantly by carefully engineering the energy dependence of the lead couplings to filter out undesired transport processes. Our findings emphasize the importance of higher-order cotunneling processes as well as engineered energy-dependent lead couplings in the optimization of the thermoelectric performance of CCQD systems.

Comparison of a model vapor deposited glass films to equilibrium glass films

NASA Astrophysics Data System (ADS)

Flenner, Elijah; Berthier, Ludovic; Charbonneau, Patrick; Zamponi, Francesco

Vapor deposition of particles onto a substrate held at around 85% of the glass transition temperature can create glasses with increased density, enthalpy, kinetic stability, and mechanical stability compared to an ordinary glass created by cooling. It is estimated that an ordinary glass would need to age thousands of years to reach the kinetic stability of a vapor deposited glass, and a natural question is how close to the equilibrium is the vapor deposited glass. To understand the process, algorithms akin to vapor deposition are used to create simulated glasses that have a higher kinetic stability than their annealed counterpart, although these glasses may not be well equilibrated either. Here we use novel models optimized for a swap Monte Carlo algorithm in order to create equilibrium glass films and compare their properties with those of glasses obtained from vapor deposition algorithms. This approach allows us to directly assess the non-equilibrium nature of vapor-deposited ultrastable glasses. Simons Collaboration on Cracking the Glass Problem and NSF Grant No. DMR 1608086.

Method for removing metal vapor from gas streams

DOEpatents

Ahluwalia, R.K.; Im, K.H.

1996-04-02

A process for cleaning an inert gas contaminated with a metallic vapor, such as cadmium, involves withdrawing gas containing the metallic contaminant from a gas atmosphere of high purity argon; passing the gas containing the metallic contaminant to a mass transfer unit having a plurality of hot gas channels separated by a plurality of coolant gas channels; cooling the contaminated gas as it flows upward through the mass transfer unit to cause contaminated gas vapor to condense on the gas channel walls; regenerating the gas channels of the mass transfer unit; and, returning the cleaned gas to the gas atmosphere of high purity argon. The condensing of the contaminant-containing vapor occurs while suppressing contaminant particulate formation, and is promoted by providing a sufficient amount of surface area in the mass transfer unit to cause the vapor to condense and relieve supersaturation buildup such that contaminant particulates are not formed. Condensation of the contaminant is prevented on supply and return lines in which the contaminant containing gas is withdrawn and returned from and to the electrorefiner and mass transfer unit by heating and insulating the supply and return lines. 13 figs.

Method for removing metal vapor from gas streams

DOEpatents

Ahluwalia, R. K.; Im, K. H.

1996-01-01

A process for cleaning an inert gas contaminated with a metallic vapor, such as cadmium, involves withdrawing gas containing the metallic contaminant from a gas atmosphere of high purity argon; passing the gas containing the metallic contaminant to a mass transfer unit having a plurality of hot gas channels separated by a plurality of coolant gas channels; cooling the contaminated gas as it flows upward through the mass transfer unit to cause contaminated gas vapor to condense on the gas channel walls; regenerating the gas channels of the mass transfer unit; and, returning the cleaned gas to the gas atmosphere of high purity argon. The condensing of the contaminant-containing vapor occurs while suppressing contaminant particulate formation, and is promoted by providing a sufficient amount of surface area in the mass transfer unit to cause the vapor to condense and relieve supersaturation buildup such that contaminant particulates are not formed. Condensation of the contaminant is prevented on supply and return lines in which the contaminant containing gas is withdrawn and returned from and to the electrorefiner and mass transfer unit by heating and insulating the supply and return lines.

Emergency Cooling of Nuclear Power Plant Reactors With Heat Removal By a Forced-Draft Cooling Tower

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murav’ev, V. P., E-mail: murval1@mail.ru

The feasibility of heat removal during emergency cooling of a reactor by a forced-draft cooling tower with accumulation of the peak heat release in a volume of precooled water is evaluated. The advantages of a cooling tower over a spray cooling pond are demonstrated: it requires less space, consumes less material, employs shorter lines in the heat removal system, and provides considerably better protection of the environment from wetting by entrained moisture.

Effectiveness-weighted control method for a cooling system

DOEpatents

Campbell, Levi A.; Chu, Richard C.; David, Milnes P.; Ellsworth Jr., Michael J.; Iyengar, Madhusudan K.; Schmidt, Roger R.; Simons, Robert E.

2015-12-15

Energy efficient control of cooling system cooling of an electronic system is provided based, in part, on weighted cooling effectiveness of the components. The control includes automatically determining speed control settings for multiple adjustable cooling components of the cooling system. The automatically determining is based, at least in part, on weighted cooling effectiveness of the components of the cooling system, and the determining operates to limit power consumption of at least the cooling system, while ensuring that a target temperature associated with at least one of the cooling system or the electronic system is within a desired range by provisioning, based on the weighted cooling effectiveness, a desired target temperature change among the multiple adjustable cooling components of the cooling system. The provisioning includes provisioning applied power to the multiple adjustable cooling components via, at least in part, the determined control settings.

Evaporation-Cooled Protective Suits for Firefighters

NASA Technical Reports Server (NTRS)

Weinstein, Leonard Murray

2007-01-01

Suits cooled by evaporation of water have been proposed as improved means of temporary protection against high temperatures near fires. When air temperature exceeds 600 F (316 C) or in the presence of radiative heating from nearby sources at temperatures of 1,200 F (649 C) or more, outer suits now used by firefighters afford protection for only a few seconds. The proposed suits would exploit the high latent heat of vaporization of water to satisfy a need to protect against higher air temperatures and against radiant heating for significantly longer times. These suits would be fabricated and operated in conjunction with breathing and cooling systems like those with which firefighting suits are now equipped

Performance characteristic of hybrid cooling system based on cooling pad and evaporator

NASA Astrophysics Data System (ADS)

Yoon, J. I.; Son, C. H.; Choi, K. H.; Kim, Y. B.; Sung, Y. H.; Roh, S. J.; Kim, Y. M.; Seol, S. H.

2018-01-01

In South Korea, most of domestic animals such as pigs and chickens might die due to thermal diseases if they are exposed to the high temperature consistently. In order to save them from the heat wave, numerous efforts have been carried out: installing a shade net, adjusting time of feeding, spraying mist and setting up a circulation fan. However, these methods have not shown significant improvements. Thus, this study proposes a hybrid cooling system combining evaporative cooler and air-conditioner in order to resolve the conventional problems caused by the high temperature in the livestock industry. The problem of cooling systems using evaporative cooling pads is that they are not effective for eliminating huge heat load due to their limited capacity. And, temperature of the supplied air cannot be low enough compared to conventional air-conditioning systems. On the other hand, conventional air-conditioning systems require relatively expensive installation cost, and high operating cost compared to evaporative cooling system. The hybrid cooling system makes up for the lack of cooling capacity of the evaporative cooler by employing the conventional air-conditioner. Additionally, temperature of supplied air can be lowered enough. In the hybrid cooling system, induced air by a fan is cooled by the evaporation of water in the cooling pad, and it is cooled again by an evaporator in the air-conditioner. Therefore, the more economical operation is possible due to additionally obtained cooling capacity from the cooling pads. Major results of experimental analysis of hybrid cooling system are as follows. The compressor power consumption of the hybrid cooling system is about 23% lower, and its COP is 17% higher than that of the conventional air-conditioners. Regarding the condition of changing ambient temperature, the total power consumption decreased by about 5% as the ambient temperature changed from 28.7°C to 31.7°C. Cooling capacity and COP also presented about 3% and 1

Method and apparatus for heat extraction by controlled spray cooling

DOEpatents

Edwards, Christopher Francis; Meeks, Ellen; Kee, Robert; McCarty, Kevin

1999-01-01

Two solutions to the problem of cooling a high temperature, high heat flux surface using controlled spray cooling are presented for use on a mandrel. In the first embodiment, spray cooling is used to provide a varying isothermal boundary layer on the side portions of a mandrel by providing that the spray can be moved axially along the mandrel. In the second embodiment, a spray of coolant is directed to the lower temperature surface of the mandrel. By taking advantage of super-Leidenfrost cooling, the temperature of the high temperature surface of the mandrel can be controlled by varying the mass flux rate of coolant droplets. The invention has particular applicability to the field of diamond synthesis using chemical vapor deposition techniques.

Outbreak of legionnaires' disease from a cooling water system in a power station.

PubMed

Morton, S; Bartlett, C L; Bibby, L F; Hutchinson, D N; Dyer, J V; Dennis, P J

1986-09-01

In September and October 1981 six cases of pneumonia occurred among men working in a power station under construction. Three were identified as cases of legionella pneumonia and two others had serology suggestive of legionella infection. In a sample of 92 men from the site 10 had low levels of antibodies to legionella; a similar sample of men working on an adjacent site showed none with positive serology. In a case control study it was found that cases of pneumonia were more likely than controls to have worked on a part of the site where four small capacity cooling towers were located. Legionella pneumophila serogroup 1 was isolated from the water systems of these four towers but was not found in samples from any other cooling towers or hot or cold water outlets on the site. It would appear that there was airborne spread of the organism from these cooling water systems which had not received conventional treatment to inhibit corrosion and organic growth. This is the first outbreak of legionnaires' disease to be recorded in an industrial setting in the United Kingdom. No cases of legionella infection have occurred on the site since the introduction of control measures.

Next-to-leading-logarithmic power corrections for N -jettiness subtraction in color-singlet production

NASA Astrophysics Data System (ADS)

Boughezal, Radja; Isgrò, Andrea; Petriello, Frank

2018-04-01

We present a detailed derivation of the power corrections to the factorization theorem for the 0-jettiness event shape variable T . Our calculation is performed directly in QCD without using the formalism of effective field theory. We analytically calculate the next-to-leading logarithmic power corrections for small T at next-to-leading order in the strong coupling constant, extending previous computations which obtained only the leading-logarithmic power corrections. We address a discrepancy in the literature between results for the leading-logarithmic power corrections to a particular definition of 0-jettiness. We present a numerical study of the power corrections in the context of their application to the N -jettiness subtraction method for higher-order calculations, using gluon-fusion Higgs production as an example. The inclusion of the next-to-leading-logarithmic power corrections further improves the numerical efficiency of the approach beyond the improvement obtained from the leading-logarithmic power corrections.

Absorption cooling sources atmospheric emissions decrease by implementation of simple algorithm for limiting temperature of cooling water

NASA Astrophysics Data System (ADS)

Wojdyga, Krzysztof; Malicki, Marcin

2017-11-01

Constant strive to improve the energy efficiency forces carrying out activities aimed at reduction of energy consumption hence decreasing amount of contamination emissions to atmosphere. Cooling demand, both for air-conditioning and process cooling, plays an increasingly important role in the balance of Polish electricity generation and distribution system in summer. During recent years' demand for electricity during summer months has been steadily and significantly increasing leading to deficits of energy availability during particularly hot periods. This causes growing importance and interest in trigeneration power generation sources and heat recovery systems producing chilled water. Key component of such system is thermally driven chiller, mostly absorption, based on lithium-bromide and water mixture. Absorption cooling systems also exist in Poland as stand-alone systems, supplied with heating from various sources, generated solely for them or recovered as waste or useless energy. The publication presents a simple algorithm, designed to reduce the amount of heat for the supply of absorption chillers producing chilled water for the purposes of air conditioning by reducing the temperature of the cooling water, and its impact on decreasing emissions of harmful substances into the atmosphere. Scale of environmental advantages has been rated for specific sources what enabled evaluation and estimation of simple algorithm implementation to sources existing nationally.

Design of the helium cooled lithium lead breeding blanket in CEA: from TBM to DEMO

NASA Astrophysics Data System (ADS)

Aiello, G.; Aubert, J.; Forest, L.; Jaboulay, J.-C.; Li Puma, A.; Boccaccini, L. V.

2017-04-01

The helium cooled lithium lead (HCLL) blanket concept was originally developed in CEA at the beginning of 2000: it is one of the two European blanket concepts to be tested in ITER in the form of a test blanket module (TBM) and one of the four blanket concepts currently being considered for the DEMOnstration reactor that will follow ITER. The TBM is a highly optimized component for the ITER environment that will provide crucial information for the development of the DEMO blanket, but its design needs to be adapted to the DEMO reactor. With respect to the TBM design, reduction of the steel content in the breeding zone (BZ) is sought in order to maximize tritium breeding reactions. Different options are being studied, with the potential of reaching tritium breeding ratio (TBR) values up to 1.21. At the same time, the design of the back supporting structure (BSS), which is a DEMO specific component that has to support the blanket modules inside the vacuum vessel (VV), is ongoing with the aim of maximizing the shielding power and minimizing pumping power. This implies a re-engineering of the modules’ attachment system. Design changes however, will have an impact on the manufacturing and assembly sequences that are being developed for the HCLL-TBM. Due to the differences in joint configurations, thicknesses to be welded, heat dissipation and the various technical constraints related to the accessibility of the welding tools and implementation of non-destructive examination (NDE), the manufacturing procedure should be adapted and optimized for DEMO design. Laser welding instead of TIG could be an option to reduce distortions. The time-of-flight diffraction (TOFD) technique is being investigated for NDE. Finally, essential information expected from the HCLL-TBM program that will be needed to finalize the DEMO design is discussed.

High-power potassium titanyl phosphate laser vaporization prostatectomy.

PubMed

Kuntzman, R S; Malek, R S; Barrett, D M

1998-08-01

In a search for potential therapeutic strategies for benign prostatic hyperplasia (BPH) that would be associated with less morbidity than transurethral resection of the prostate, various types of laser prostatectomy have been used. Although the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser allows performance of prostatectomy in an almost bloodless field and without absorption of irrigant, the remaining necrotic tissue causes bladder outlet obstruction and related symptoms for 5 to 7 days after treatment. In contrast, the potassium titanyl phosphate (KTP) laser has been found to vaporize tissue with minimal coagulation of the underlying structures. With use of the KTP laser, heat is concentrated into a small volume, the tissue is ablated by rapid vaporization of cellular water, and a 2-mm rim of coagulated tissue is left. After favorable results were obtained in studies of canine prostates and human cadavers, we implemented clinical use of 60-W KTP laser prostatectomy in selected patients. In 10 patients with symptomatic BPH who ranged in age from 52 to 80 years, outpatient KTP laser prostatectomy yielded significantly increased mean peak urinary flow rates (from 8.0 mL/s preoperatively to 19.4 mL/s within 24 hours after the procedure). No patient had hematuria, dysuria, or incontinence after removal of the catheter, and no patient required recatheterization. One patient, however, had urgency, and two other patients became febrile during the 24-hour observation period. Overall, KTP laser vaporization prostatectomy can provide immediate relief from obstructive symptoms of BPH and is not associated with dysuria.

Alkali Metal Backup Cooling for Stirling Systems - Experimental Results

NASA Technical Reports Server (NTRS)

Schwendeman, Carl; Tarau, Calin; Anderson, William G.; Cornell, Peggy A.

2013-01-01

In a Stirling Radioisotope Power System (RPS), heat must be continuously removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. The Stirling convertor normally provides this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS at the cost of an early termination of the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) can be used to passively allow multiple stops and restarts of the Stirling convertor. In a previous NASA SBIR Program, Advanced Cooling Technologies, Inc. (ACT) developed a series of sodium VCHPs as backup cooling systems for Stirling RPS. The operation of these VCHPs was demonstrated using Stirling heater head simulators and GPHS simulators. In the most recent effort, a sodium VCHP with a stainless steel envelope was designed, fabricated and tested at NASA Glenn Research Center (GRC) with a Stirling convertor for two concepts; one for the Advanced Stirling Radioisotope Generator (ASRG) back up cooling system and one for the Long-lived Venus Lander thermal management system. The VCHP is designed to activate and remove heat from the stopped convertor at a 19 C temperature increase from the nominal vapor temperature. The 19 C temperature increase from nominal is low enough to avoid risking standard ASRG operation and spoiling of the Multi-Layer Insulation (MLI). In addition, the same backup cooling system can be applied to the Stirling convertor used for the refrigeration system of the Long-lived Venus Lander. The VCHP will allow the refrigeration system to: 1) rest during transit at a lower temperature than nominal; 2) pre-cool the modules to an even lower temperature before the entry in Venus atmosphere; 3) work at nominal temperature on Venus surface; 4) briefly stop multiple times on the Venus surface to allow scientific measurements. This paper presents the experimental

Alkali Metal Backup Cooling for Stirling Systems - Experimental Results

NASA Technical Reports Server (NTRS)

Schwendeman, Carl; Tarau, Calin; Anderson, William G.; Cornell, Peggy A.

2013-01-01

In a Stirling Radioisotope Power System (RPS), heat must be continuously removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. The Stirling convertor normally provides this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS at the cost of an early termination of the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) can be used to passively allow multiple stops and restarts of the Stirling convertor. In a previous NASA SBIR Program, Advanced Cooling Technologies, Inc. (ACT) developed a series of sodium VCHPs as backup cooling systems for Stirling RPS. The operation of these VCHPs was demonstrated using Stirling heater head simulators and GPHS simulators. In the most recent effort, a sodium VCHP with a stainless steel envelope was designed, fabricated and tested at NASA Glenn Research Center (GRC) with a Stirling convertor for two concepts; one for the Advanced Stirling Radioisotope Generator (ASRG) back up cooling system and one for the Long-lived Venus Lander thermal management system. The VCHP is designed to activate and remove heat from the stopped convertor at a 19 degC temperature increase from the nominal vapor temperature. The 19 degC temperature increase from nominal is low enough to avoid risking standard ASRG operation and spoiling of the Multi-Layer Insulation (MLI). In addition, the same backup cooling system can be applied to the Stirling convertor used for the refrigeration system of the Long-lived Venus Lander. The VCHP will allow the refrigeration system to: 1) rest during transit at a lower temperature than nominal; 2) pre-cool the modules to an even lower temperature before the entry in Venus atmosphere; 3) work at nominal temperature on Venus surface; 4) briefly stop multiple times on the Venus surface to allow scientific measurements. This paper presents the experimental

Vaporization of irradiated droplets

NASA Astrophysics Data System (ADS)

Armstrong, R. L.; O'Rourke, P. J.; Zardecki, A.

1986-11-01

The vaporization of a spherically symmetric liquid droplet subject to a high-intensity laser flux is investigated on the basis of a hydrodynamic description of the system composed of the vapor and ambient gas. In the limit of the convective vaporization, the boundary conditions at the fluid-gas interface are formulated by using the notion of a Knudsen layer in which translational equilibrium is established. This leads to approximate jump conditions at the interface. For homogeneous energy deposition, the hydrodynamic equations are solved numerically with the aid of the CON1D computer code (``CON1D: A computer program for calculating spherically symmetric droplet combustion,'' Los Alamos National Laboratory Report No. LA-10269-MS, December, 1984), based on the implict continuous-fluid Eulerian (ICE) [J. Comput. Phys. 8, 197 (1971)] and arbitrary Lagrangian-Eulerian (ALE) [J. Comput. Phys. 14, 1227 (1974)] numerical mehtods. The solutions exhibit the existence of two shock waves propagating in opposite directions with respect to the contact discontinuity surface that separates the ambient gas and vapor.

18 CFR 420.44 - Cooling water.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Cooling water. 420.44 Section 420.44 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS-WATER SUPPLY CHARGES Charges; Exemptions § 420.44 Cooling water. Water used...

18 CFR 420.44 - Cooling water.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Cooling water. 420.44 Section 420.44 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS-WATER SUPPLY CHARGES Charges; Exemptions § 420.44 Cooling water. Water used...

18 CFR 420.44 - Cooling water.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Cooling water. 420.44 Section 420.44 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS-WATER SUPPLY CHARGES Charges; Exemptions § 420.44 Cooling water. Water used...

18 CFR 420.44 - Cooling water.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Cooling water. 420.44 Section 420.44 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS-WATER SUPPLY CHARGES Charges; Exemptions § 420.44 Cooling water. Water used...

18 CFR 420.44 - Cooling water.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Cooling water. 420.44 Section 420.44 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS-WATER SUPPLY CHARGES Charges; Exemptions § 420.44 Cooling water. Water used...

Implications of Climate Change on the Heat Budget of Lentic Systems Used for Power Station Cooling: Case Study Clinton Lake, Illinois.

PubMed

Quijano, Juan C; Jackson, P Ryan; Santacruz, Santiago; Morales, Viviana M; García, Marcelo H

2016-01-05

We use a numerical model to analyze the impact of climate change-in particular higher air temperatures-on a nuclear power station that recirculates the water from a reservoir for cooling. The model solves the hydrodynamics, the transfer of heat in the reservoir, and the energy balance at the surface. We use the numerical model to (i) quantify the heat budget in the reservoir and determine how this budget is affected by the combined effect of the power station and climate change and (ii) quantify the impact of climate change on both the downstream thermal pollution and the power station capacity. We consider four different scenarios of climate change. Results of simulations show that climate change will reduce the ability to dissipate heat to the atmosphere and therefore the cooling capacity of the reservoir. We observed an increase of 25% in the thermal load downstream of the reservoir, and a reduction in the capacity of the power station of 18% during the summer months for the worst-case climate change scenario tested. These results suggest that climate change is an important threat for both the downstream thermal pollution and the generation of electricity by power stations that use lentic systems for cooling.

Implications of climate change on the heat budget of lentic systems used for power station cooling: Case study Clinton Lake, Illinois

USGS Publications Warehouse

Quijano, Juan C; Jackson, P. Ryan; Santacruz, Santiago; Morales, Viviana M; Garcia, Marcelo H.

2016-01-01

We use a numerical model to analyze the impact of climate change--in particular higher air temperatures--on a nuclear power station that recirculates the water from a reservoir for cooling. The model solves the hydrodynamics, the transfer of heat in the reservoir, and the energy balance at the surface. We use the numerical model to (i) quantify the heat budget in the reservoir and determine how this budget is affected by the combined effect of the power station and climate change and (ii) quantify the impact of climate change on both the downstream thermal pollution and the power station capacity. We consider four different scenarios of climate change. Results of simulations show that climate change will reduce the ability to dissipate heat to the atmosphere and therefore the cooling capacity of the reservoir. We observed an increase of 25% in the thermal load downstream of the reservoir, and a reduction in the capacity of the power station of 18% during the summer months for the worst-case climate change scenario tested. These results suggest that climate change is an important threat for both the downstream thermal pollution and the generation of electricity by power stations that use lentic systems for cooling.

Attribution of the United States "warming hole": aerosol indirect effect and precipitable water vapor.

PubMed

Yu, Shaocai; Alapaty, Kiran; Mathur, Rohit; Pleim, Jonathan; Zhang, Yuanhang; Nolte, Chris; Eder, Brian; Foley, Kristen; Nagashima, Tatsuya

2014-11-06

Aerosols can influence the climate indirectly by acting as cloud condensation nuclei and/or ice nuclei, thereby modifying cloud optical properties. In contrast to the widespread global warming, the central and south central United States display a noteworthy overall cooling trend during the 20(th) century, with an especially striking cooling trend in summertime daily maximum temperature (Tmax) (termed the U.S. "warming hole"). Here we used observations of temperature, shortwave cloud forcing (SWCF), longwave cloud forcing (LWCF), aerosol optical depth and precipitable water vapor as well as global coupled climate models to explore the attribution of the "warming hole". We find that the observed cooling trend in summer Tmax can be attributed mainly to SWCF due to aerosols with offset from the greenhouse effect of precipitable water vapor. A global coupled climate model reveals that the observed "warming hole" can be produced only when the aerosol fields are simulated with a reasonable degree of accuracy as this is necessary for accurate simulation of SWCF over the region. These results provide compelling evidence of the role of the aerosol indirect effect in cooling regional climate on the Earth. Our results reaffirm that LWCF can warm both winter Tmax and Tmin.

Growth of high-quality thin-film Ge single crystals by plasma-enhanced chemical vapor deposition

NASA Technical Reports Server (NTRS)

Outlaw, R. A.; Hopson, P., Jr.

1986-01-01

Thin-film Ge single crystals (approx. 10 microns) have been epitaxially grown on polished NaCl(100) substrates at 450C by using plasma-enhanced chemical vapor deposition. Films on approximately 1 sq cm and larger were separated from the NaCl by either melting the salt or by differential shear stress upon cooling to room temperature. The ordered growth of the Ge was found to be most sensitive to the initial plasma power and to the continuum flow dynamics within the carbon susceptor. The films were visually specular and exhibited a high degree of crysalline order when examined by X-ray diffraction. The films were found to be p-type with a carrier concentration of approximately 3 x 10 to the 16th power/cu cm, a resistivity of 0.11 ohm-cm, and a Hall hole mobility of 1820 sq cm/v/s at room temperature. Vacuum firing minimized the primary contaminant, Na, and corresponding lowered the carrier concentration to 4 x 10 to the 14th power/cu cm.

DSMC simulations of vapor transport toward development of the lithium vapor box divertor concept

NASA Astrophysics Data System (ADS)

Jagoe, Christopher; Schwartz, Jacob; Goldston, Robert

2016-10-01

The lithium vapor divertor box concept attempts to achieve volumetric dissipation of the high heat efflux from a fusion power system. The vapor extracts the heat of the incoming plasma by ionization and radiation, while remaining localized in the vapor box due to differential pumping based on rapid condensation. Preliminary calculations with lithium vapor at densities appropriate for an NSTX-U-scale machine give Knudsen numbers between 0.01 and 1, outside both the range of continuum fluid dynamics and of collisionless Monte Carlo. The direct-simulation Monte Carlo (DSMC) method, however, can simulate rarefied gas flows in this regime. Using the solver contained in the OpenFOAM package, pressure-driven flows of water vapor will be analyzed. The use of water vapor in the relevant range of Knudsen number allows for a flexible similarity experiment to verify the reliability of the code before moving to tests with lithium. The simulation geometry consists of chains of boxes on a temperature gradient, connected by slots with widths that are a representative fraction of the dimensions of the box. We expect choked flow, sonic shocks, and order-of-magnitude pressure and density drops from box to box, but this expectation will be tested in the simulation and then experiment. This work is supported by the Princeton Environmental Institute.

Summary Report On Design And Development Of High Temperature Gas-Cooled Power Pile

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCullough, C. R.

1947-09-15

This report presents a description of a design for an experimental nuclear power plant utilizing a high temperature gas-cooled power pile as the energy source. The plant consists of the pile, a heat exchanger or boiler, a conventional steam turbine generator and their associated auxiliaries. Helium gas under pressure transfers heat from the pile to the boiler which generates steam for driving the generator. The plant is rated at a normal output of 12,000 kilowatts of heat and an electrical output of 2400 kilowatts. Provision is made for operation up to 20,000 kilowatts of heat (4000 kilowatts of electrical output)more » in the event operation of the plants proves this possible.« less

Cool down time optimization of the Stirling cooler

NASA Astrophysics Data System (ADS)

Xia, M.; Chen, X. P.; Y Li, H.; Gan, Z. H.

2017-12-01

The cooling power is one of the most important performances of a Stirling cooler. However, in some special fields, the cool down time is more important. It is a great challenge to improve the cool down time of the Stirling cooler. A new split Stirling linear cryogenic cooler SCI09H was designed in this study. A new structure of linear motor is used in the compressor, and the machine spring is used in the expander. In order to reduce the cool down time, the stainless-steel mesh of regenerator is optimized. The weight of the cooler is 1.1 kg, the cool down time to 80K is 2 minutes at 296K with a 250J thermal mass, the cooling power is 1.1W at 80K, and the input power is 50W.

Cool Vest

NASA Technical Reports Server (NTRS)

1982-01-01

ILC, Dover Division's lightweight cooling garment, called Cool Vest was designed to eliminate the harmful effects of heat stress; increases tolerance time in hot environments by almost 300 percent. Made of urethane-coated nylon used in Apollo, it works to keep the body cool, circulating chilled water throughout the lining by means of a small battery-powered pump. A pocket houses the pump, battery and the coolant which can be ice or a frozen gel, a valve control allows temperature regulation. One version is self-contained and portable for unrestrained movement, another has an umbilical line attached to an external source of coolant, such as standard tap water, when extended mobility is not required. It is reported from customers that the Cool Vest pays for itself in increased productivity in very high temperatures.

Stirling Air Conditioner for Compact Cooling

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2010-09-01

BEETIT Project: Infinia is developing a compact air conditioner that uses an unconventional high efficient Stirling cycle system (vs. conventional vapor compression systems) to produce cool air that is energy efficient and does not rely on polluting refrigerants. The Stirling cycle system is a type of air conditioning system that uses a motor with a piston to remove heat to the outside atmosphere using a gas refrigerant. To date, Stirling systems have been expensive and have not had the right kind of heat exchanger to help cool air efficiently. Infinia is using chip cooling technology from the computer industry tomore » make improvements to the heat exchanger and improve system performance. Infinia’s air conditioner uses helium gas as refrigerant, an environmentally benign gas that does not react with other chemicals and does not burn. Infinia’s improvements to the Stirling cycle system will enable the cost-effective mass production of high-efficiency air conditioners that use no polluting refrigerants.« less

Fabrication of lithium/C-103 alloy heat pipes for sharp leading edge cooling

NASA Astrophysics Data System (ADS)

Ai, Bangcheng; Chen, Siyuan; Yu, Jijun; Lu, Qin; Han, Hantao; Hu, Longfei

2018-05-01

In this study, lithium/C-103 alloys heat pipes are proposed for sharp leading edge cooling. Three models of lithium/C-103 alloy heat pipes were fabricated. And their startup properties were tested by radiant heat tests and aerothermal tests. It is found that the startup temperature of lithium heat pipe was about 860 °C. At 1000 °C radiant heat tests, the operating temperature of lithium/C-103 alloy heat pipe is lower than 860 °C. Thus, startup failure occurs. At 1100 °C radiant heat tests and aerothermal tests, the operating temperature of lithium/C-103 alloy heat pipe is higher than 860 °C, and the heat pipe starts up successfully. The startup of lithium/C-103 alloy heat pipe decreases the leading edge temperature effectively, which endows itself good ablation resistance. After radiant heat tests and aerothermal tests, all the heat pipe models are severely oxidized because of the C-103 poor oxidation resistance. Therefore, protective coatings are required for further applications of lithium/C-103 alloy heat pipes.

[Net power and energy of cooled antenna microwave ablation:ex vivo versus in vivo results in porcine liver].

PubMed

Jiang, Hua; Fan, Wei-jun; Zhang, Liang; Li, Xin; Zhang, Jian-lei

2012-09-18

To explore the net power and net energy of a cooled antenna radiator in ex vivo and in vivo porcine livers. All animal experiments complied with the guidelines of our animal use committee. Microwave ablation (MWA) was performed in ex vivo and in vivo porcine livers with a cooled-shaft antenna in different microwave ablation parameter groups (50, 80 and 110 W for 10 min). The energy losses from the microwave antenna or cables were calculated. And the net power, net energy and the relationship between net power and power readout were determined. When the power displayed by the machine indicated 50 W, 80 W and 110 W, the net power during MWA was 31.3 ± 0.6, 47.3 ± 0.8 and 62.1 ± 0.9 W ex vivo and 31.8 ± 0.8, 47.4 ± 0.3 and 61.7 ± 1.5 W in vivo. For the same power readout, the ex vivo or in vivo effective power was the same (P = 0.841, P = 0.133, P = 0.551). For both ex vivo and in vivo experiments, the ratio of microwave antenna energy loss to microwave antenna input energy was relatively constant (P = 0.613, 0.326). For the same treatment time and net power, the difference was significant between ex vivo and in vivo ablation volumes (P = 0.001, 0.006, 0.001). Using net power as a reference during MWA is more accurate compared to the traditional power readout. And net energy offers a more realistic reflection of MWA energy in tissues.