Steady-state analysis of a Capillary Pumped Loop for Terrestrial Application with methanol and ethanol as working fluids

Abstract

This paper aims to study and understand the behaviour of a CPLTA (Capillary Pumped Loop for Terrestrial Applications) in different operating conditions. This CPL, designed for power electronics cooling applications, has been analysed from two different points of view by comparing its operating behaviour with Ethanol and Methanol as working fluids. The influence of the fluids on CPLTA was experimentally explored by modifying: the thermal characteristics (applied heat flux density on the evaporator walls, saturation temperature in the reservoir and condenser inlet temperature) and the hydraulic characteristics (by acting on a setting valve to generate controlled and increasing pressure losses in the vapour line) in order to show how they impact the behaviour of the loop. Thermal aspects of the loop were analysed, including changes of evaporator conductance. To obtain the thermodynamic cycles and evaporator conductance, based on the real evaporation temperature in the porous wick, a theoretical study was conducted using a specific post-processing tool.