Proof of Concept High Lift Heat Pump for a Lunar Base

Morton, R. B.; Bergeron, D. E.; Hurlbert, Kathryn Miller; Ewert, Michael K.; Cornwell, J. D.

doi:10.4271/981683

Cited by 5 publications

(4 citation statements)

References 4 publications

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“…Superheated vapor at point (3) enters the compressor and gets compressed to a higher pressure and temperature at point (4). The high pressure vapor enters the condenser at point (5) and is cooled to saturated liquid at point (6) and further subcooled to a lower temperature at point (7). The subcooled liquid flows to the expansion valve inlet (8) and undergoes the reduction in pressure that results in an adiabatic evaporation of a portion of the liquid refrigerant.…”

Section: Figure 2: Simplified Model Of the Avclmentioning

confidence: 99%

“…There were four critical positions in the loop: evaporator inlet (1), evaporator outlet (2), condenser inlet (5), and expansion valve inlet (8). As long as the thermodynamics properties of these locations are identified, the operation mechanism and the performance of AVCL is fully defined.…”

Section: Figure 2: Simplified Model Of the Avclmentioning

confidence: 99%

“…The objective of the thermal control systems (TCS) of the Altair Lunar Lander is to maintain the cabin and electronics temperatures within acceptable levels anywhere on the lunar surface during the hot lunar daytime. This is challenging because the lunar surface temperature at the equator can range from -173°C to 121°C [1][2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

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Evaporators for High Temperature Lift Vapor Compression Loop for Space Applications

Semenic

Tang

2009

Volume 2: Theory and Fundamental Research; Aerospace Heat Transfer; Gas Turbine Heat Transfer; Computational Heat Transfer

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An Advanced Vapor Compression Loop (AVCL) for high temperature lift for heat rejection to hot lunar surface during lunar daytime was developed. The loop consists of an evaporator, a compressor, a condenser, and an electronic expansion valve. Different types of evaporators were evaluated in this study: a circular tube evaporator, a circular tube evaporator with a twisted tape, a circular tube evaporator with a wick, and a circular tube evaporator with a wick and a twisted tape. The evaporators were tested with two different compressors. The first was a 0.5hp oil-less compressor and the second was a 5.3hp compressor that used oil as lubricant. A heat exchanger (recuperator) was used to subcool the high pressure liquid and to superheat the low pressure vapor. Tests were performed with and without the recuperator. Vapor superheat during the tests was controlled with an electronic expansion valve controller. The working fluid was R134a. The results show that the heat source-to-working fluid thermal resistance of the circular tube evaporator with the wick and the twisted tape was one-third of that of the circular tube evaporator. The recuperator was able to decrease the vapor quality at the evaporator inlet and increase the vapor superheat at the compressor inlet. The evaporators without wicks were able to operate at a heat flux of 5.7W/cm2 with the recuperator and vapor superheat set at 5°C. Evaporators with wicks reached dryout at lower heat fluxes when maintaining superheat at 5°C. However, the wicked evaporators reached a heat flux of 7.6W/cm2 when decreasing superheat below 5°C. A temperature lift of 70°C was achieved with the 5.3hp compressor.

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Section: Figure 2: Simplified Model Of the Avclmentioning

confidence: 99%

Section: Figure 2: Simplified Model Of the Avclmentioning

confidence: 99%

See 1 more Smart Citation

Evaporators for High Temperature Lift Vapor Compression Loop for Space Applications

Semenic

Tang

2009

Volume 2: Theory and Fundamental Research; Aerospace Heat Transfer; Gas Turbine Heat Transfer; Computational Heat Transfer

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“…Heat pump technology is among the most promising thermal management technologies for future spacecraft and planetary bases (Morton et al , 1998; Lee et al , 2016). It has considerable potential to achieve a high coefficient of performance and drastically reduce the mass of the thermal control system for high heat loads and heat environments.…”

Section: Introductionmentioning

confidence: 99%

Numerical and experimental study on the static performance of externally pressurized thrust bearings lubricated with refrigerant gases

Rong

Lian

2021

ILT

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Purpose Oil-free heat pumps that use the system refrigerant gases as lubricants are preferred for thermal management in future space applications. This study aims to numerically and experimentally investigate the static performance of externally pressurized thrust bearings lubricated with refrigerant gases. Design/methodology/approach The refrigerant gases R22, R410A and CO2 were chosen as the research objects, while N2 was used for comparison. Computational fluid dynamics was used to solve the full 3 D Navier–Stokes equations to determine the load capacity, static stiffness and static pressure distribution in the bearing film. The numerical results were experimentally verified. Findings The results showed that the refrigerant-gas-lubricated thrust bearings had a lower load capacity than the N2-lubricated bearings, but they presented a higher static stiffness when the bearing clearance was less than 9 µm. Compared with the N2-lubricated bearings, the optimal static stiffness of the R22- and CO2-lubricated bearings increased by more than 46% and more than 21%, respectively. The numerical and experimental results indicate that a small bearing clearance would be preferable when designing externally pressurized gas thrust bearings lubricated with the working medium of heat pump systems for space applications. Originality/value The findings of this study can serve as a basis for the further investigation of refrigerant gases as lubricants in heat pump systems, as well as for the future design of such gas bearings in heat pump systems for space applications.

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Spacecraft Thermal Management

Hurlbert

2010

Encyclopedia of Aerospace Engineering

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All spacecraft must include a thermal control system (TCS) to maintain equipment and/or crew within tolerable temperature limits during the mission. This chapter provides an overview of spacecraft thermal control systems design and development, with descriptions of the passive and active subsystems and associated components. The necessary steps in the design process are also provided, including establishing mission and system requirements, characterizing the mission environments, developing the design concept and models, and planning a test program to ensure the system functions as expected.

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Proof of Concept High Lift Heat Pump for a Lunar Base

Cited by 5 publications

References 4 publications

Evaporators for High Temperature Lift Vapor Compression Loop for Space Applications

Evaporators for High Temperature Lift Vapor Compression Loop for Space Applications

Numerical and experimental study on the static performance of externally pressurized thrust bearings lubricated with refrigerant gases

Spacecraft Thermal Management

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