Dynamic characteristics of an integrated cooling system comprising vapor compression and thermosyphon loop for electronics cooling

An integrated cooling system comprising passive cooling-thermosyphon loop and active cooling-vapor compression was proposed for the cooling of electronics, especially avionics, under a wide range of heat loads and ambient temperatures. A prototype of the integrated system with the weight of 2.8 kg was developed by microchannel heat exchangers and a micro rotary compressor. The dynamic characteristics of the thermosyphon loop mode and vapor compression mode, and the switching mode were investigated experimentally, with second as time scale. Under the premise that the average wall temperature does not exceed 50 °C, the thermosyphon loop mode can handle a heat load of 600 W with COP of 35.7, and the vapor compression mode can handle a heat load of about 1000 W with COP of 3.1, at the ambient temperature of 20 °C. The developed integrated cooling system can effectively handle the sharp change in heat load (two heat loads of 400 W and 800 W like square wave) and ambient temperature (from 10 °C to 32 °C) by switching working modes. It automatically switched to TL mode at low heat load and ambient temperature for energy conservation, and switched to VC mode at high heat load and ambient temperature for safety.