INVESTIGATIONS ON FLOW AND HEAT TRANSFER CHARACTERISTICS IN A MPFL SYSTEM WITH MICRO CHANNELS WITH DIFFERENT WORKING FLUIDS
Micro-channel heat sinks find their application in several emerging electronic cooling areas due to miniaturization of electronic components over the last few decades. Considering the need of thermal management of high heat flux electronics of ISRO spacecraft, interplanetary missions and human space mission, development of a two-phase mechanically pumped fluid loop (MPFL) system has been taken up at Thermal Systems Group of ISRO Satellite Centre, and a 2-∅ MPFL with micro-channel evaporator has been fabricated and tested with various fluids − acetone, ethanol and n-pentane. These fluids were chosen based on the application in the spacecraft components cooling and also limited availability of data in the literature. Heat transfer characteristics show that the acetone giving the better thermal performance (8500 W/m2.°C) at lower vapour qualities and ethanol at higher qualities compared to other fluids.
This paper presents the experimental studies of flow and heat transfer characteristics of two phase MPFL with evaporator having multiple straight parallel micro channels (500µm (W) x 500µm (D) x 50 mm (L) ), consists of various parameters such as evaporator temperature, mass flow rate, outlet vapor quality, and heat transfer coefficient for three different working fluids.