Quiet power-free cooling system enabled by loop heat pipe

Taking full advantage of LHP’s efficient long distance heat transport capability, a LHP-based power-free cooling system has been developed in this work. The heat source was simulated by a film heater, which was connected to the cylindrical evaporator of the LHP via an aluminum saddle. The condenser line was embedded into the bottom surface of a fin radiator where heat dissipation to the ambient was completely by air natural convection. Extensive experiments on this cooling system were conducted, mainly focusing on its startup and system thermal resistance. Experimental results show that this cooling system can successfully start up with a very small heat load. With the film heater temperature not exceeding 80 °C, this cooling system can manage a heat load as large as 150 W over a distance of 1.05 m, corresponding to a system thermal resistance about 0.30 °C/W. Moreover, this cooling system exhibited very strong anti-gravity capability. With an adverse elevation of 0.5 m, it can still maintain normal operation, and no obvious performance decay was observed except an increased operating temperature at small heat loads. This work provides good design guidance and reference for future applications of this advanced cooling system.