Evaluation of the performance of a magnetic-shuttle micropump in a two-phase mechanical pumping loop

In order to dissipate large amount of heat, two-phase (2-Φ) mechanical pumping loops (MPLs) are often required. Compared to their passive counterparts, such as heat pipes, 2-ΦMPLs are also suitable for distributed payloads and can improve the uniformity of surface temperature. One of the main issues, however, with both single-phase and 2-Φ MPLs is the reliability of the pump as its failure directly results in a failure of the whole cooling system, leading to overheating of the electronic components. Moreover, the micropump is required to withstand the high working pressures (above 6 MPa) necessary in 2-Φ MPL working with refrigerant such as CO2 or ammonia. The size and weight of the pump is often an issue in electronic cooling of small space satellites, drones or servers that affects the widespread implementation of MPL technologies. To overcome issues with reliability, high working pressures and compact form factors, a novel micropump based on a patented counter-wound solenoid coil technology and a fast response flow meter were developed by the authors. In this paper, the integration of the micropump and flow meter in a flow control unit for 2-Φ MPL system using Novec 7100 as working fluid will be presented. Two different tests were carried out to evaluate the heat dissipation capability of the unit in different working conditions: Test 1 studied the effect of input pump power on heat dissipation, while Test 2 investigated the effects of different condenser coolant temperatures. It was shown that when the input pump power was 0.5 W, up to 325 W (15.3 W/cm3) of heat power could be dissipated by the loop.