Thermal Control with Low Power, Miniature Loop Heat Pipes 1999-01-2008
A miniature Loop Heat Pipe (LHP) has been designed, built and tested at Dynatherm Corp. Inc. (DCI). This small, 229 mm by 127mm, ammonia charged LHP is intended to provide thermal management and temperature control for electronic components, especially for spacecraft applications. The mini-LHP has been successfully tested at DCI in various orientations, and has demonstrated the ability to maintain the LHP evaporator temperature at the simulated electronic heat source within ±0.25°C for heat loads between 5 and 10 watts, and evaporator minus condenser temperature differences as high as 82°C.
This paper discusses the steady state and transient behavior of the mini LHP during different operational modes. The nature of the temperature fluctuations observed during mini LHP testing is dependent on the specific temperature control concept. In order to minimize these instabilities, several LHP design and control strategy options are discussed.