Experimental Study on the Transient Behaviors of Mechanically Pumped Two-Phase Loop with a Phase Change Energy Storage Device for Short Time and Large Heat Power Dissipation of Spacecraft

Abstract

For the purpose of dissipating large heat power with cyclical operating modes of satellite, one mechanically pumped two-phase loop (MPTL) coupled with a novel phase change energy storage device was designed and constructed. The phase change energy storage device integrating with filament tube heat exchanger and form-stable phase change material (PCM) with expanded graphite (EG) was designed and employed to increase the conductivity. The two-phase change behavior of liquid-vapor change for MPTL and solid-liquid transition for PCM was used to acquire, transport and store the heat. Results indicated that the time of heat storage for PCM device was more than 598.0 s, and the temperature at the outlet of the device increased from −2.0 °C to 15.0 °C under the heating power of 6.7 kW. The flowrate decreased from 0.059 kg/s to 0.034 kg/s due to the length increase of two-phase section during the melting process of PCM device. Lowering the rotation speed of pump increased the oscillating amplitude of flowrate, and its maximum value reached to 0.008 kg/s. The total working period for PCM device for lower rotation speed of 8000 r/min was 48.0 s longer than that for higher speed of 10000 r/min due to decreased heat transfer coefficient.