Heat Rejection Concepts for Lunar Fission Surface Power Applications

Siamidis, John

doi:10.2514/6.2006-4196

Cited by 6 publications

(2 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A heat exchanger must be designed to transfer heat into the LHP evaporator. Siamidis (2006) proposed a heat exchanger design for a titanium/water heat pipe radiator that used graphite foam as the thermal interface between the heat pipes and secondary loop from the energy conversion equipment. This design could be adapted to a LHP radiator…”

Section: Test Results and Discussionmentioning

confidence: 99%

Titanium Loop Heat Pipes for Space Nuclear Power Systems

Hartenstine¹,

Anderson²,

Bonner³

et al. 2008

AIP Conference Proceedings

View full text Add to dashboard Cite

Space nuclear power systems require a radiator to dissipate the waste heat generated during the thermal-toelectric conversion process. A previously conducted radiator trade study showed that radiators with titanium/water Loop Heat Pipes (LHP) have the highest specific power (ratio of heat dissipation to radiator mass) in the temperature range from 300 K to 550 K. A prototype titanium/water LHP was designed and fabricated to operate within this temperature range. The LHP was all titanium, to eliminate incompatibility problems between water and dissimilar metals. The LHP had a 2.54 cm (1 inch) CD., 20 cm (8 in.) long evaporator wick, and was designed to carry 500 W of heat load. The liquid and vapor lines were roughly 2 m long, typical of the requirements for a spacecraft radiator. The LHP was tested to more than 550 W, at an adverse elevation of 5 cm and an operating temperature of 413 K. This paper describes the details of the titanium/water LHP design, wick development, and titanium LHP fabrication and tests.

show abstract

Section: Test Results and Discussionmentioning

confidence: 99%

Titanium Loop Heat Pipes for Space Nuclear Power Systems

Hartenstine¹,

Anderson²,

Bonner³

et al. 2008

AIP Conference Proceedings

View full text Add to dashboard Cite

show abstract

“…NASA is interested in Brayton cycle converters for nuclear space power system (Siamidis, 2006;, Siamidis and Mason, 2006) A radiator is required to dissipate the waste heat generated during the thermal-to-electric conversion process. A pumped sodium-potassium (NaK) or water secondary loop is used to transfer waste heat from the power converters to the heat pipe radiator.…”

Section: Introductionmentioning

confidence: 99%

Intermediate Temperature Fluids Life Tests — Theory

Tarau

Sarraf²,

Locci

et al. 2007

AIP Conference Proceedings

View full text Add to dashboard Cite

There are a number of different applications that could use heat pipes or loop heat pipes (LHPs) in the intermediate temperature range of 450 to 750 K, including space nuclear power system radiators, and high temperature electronics cooling. Potential working fluids include organic fluids, elements, and halides, with halides being the least understood, with only a few life tests conducted. Potential envelope materials for halide working fluids include pure aluminum, aluminum alloys, commercially pure (CP) titanium, titanium alloys, and corrosion resistant superalloys. Life tests were conducted with three halides (AlBr 3 , SbBr 3 , and TiCl 4) and water in three different envelopes: two aluminum alloys (Al-5052, Al-6061) and CP-2 titanium. The AlBr 3 attacked the grain boundaries in the aluminum envelopes, and formed TiAl compounds in the titanium. The SbBr 3 was incompatible with the only envelope material that it was tested with, Al-6061. TiCl 4 and water were both compatible with CP2-titanium. A theoretical model was developed that uses electromotive force differences to predict the compatibility of halide working fluids with envelope materials. This theory predicts that iron, nickel, and molybdenum are good envelope materials, while aluminum and titanium halides are good working fluids. The model is in good agreement with results from previous life tests, as well as the current life tests.

show abstract