Loop Heat Pipes and mini-Vapour Cycle System for Helicopter Avionics Electronic Thermal Management

摘要

With the increase of heat flux densities generated by electronics, manufacturers are facing tremendous new challenges in which component heat flux might reach 100 W/cm~2. This scenario is pushing the research efforts towards the development of alternative solutions, which will be able to ensure the needed cooling demands of high-integrated electronics. Furthermore, when considering the aeronautical applications, the reliability, compactness, and lightness of the cooling systems represent essential and mandatory characteristics. With the continuous miniaturization of the components, passive and active two-phase cooling devices can now be applied to electronics systems while maintaining the fundamental compactness and lightness of the whole system. This paper presents the experimental assessment of an electronic cooling prototype especially designed for helicopter avionics thermal management in the framework of 7th FP EU project TOICA (Thermal Overall Integrated Conception of Aircraft, www.toica-fp7.eu). The prototype consists of a set of compact Loop Heat Pipes (LHPs) especially designed for the hot spot treatment at blade level and an air cooled mini-Vapor Cycle System (mini-VCS), which is devoted to the overall heat rejection. One innovative concept of this system design lies in the presence of a thermal connector, named thermal plug, which acts as the evaporator of the mini-VCS, that cools down the LHP condenser. The experimental results are carried out at different hot spot heat loads, from 10 W to 50 W. The effect of different heat sink temperatures on the LHP thermal resistance is investigated. Furthermore, for a fixed evaporating temperature of the mini-VCS, the effects of vapor superheating at the outlet of the plug evaporator on the LHP thermal resistance is investigated. The proposed preliminary results allow to exploit the potentiality to use the proposed cooling technology in a typical airborne scenario.