Ground Test and on-Orbit Verification of a Mechanically Pumped Two-Phase Loop Using for Thermal Control of Spacecraft

Abstract

Mechanically pumped two-phase loop (MPTL) is an advanced two-phase heat transfer device through the release of latent heat of phase change during flow boiling process. In order to investigate the performance of MPTL system under different gravity conditions, one MPTL setup using a novel two-phase thermal-controlled accumulator coupled with self-cooling function was designed and constructed. Its characteristics of startup, phase change, and temperature control were tested on the ground and on orbit. Test results showed that MPTL system had good working performance and stable working characteristics both on the ground and on a satellite. The functions of fluid management, temperature control and self-cooling for accumulator were verified under different gravity conditions. It was found that the superheat time and superheat temperature for on-orbit results were longer and higher than the ground’s results respectively. The heat transfer efficient of two-phase flow of MPTL system could reach 12,000 − 60,000 W/(m2·K). Affected by the buoyancy, the heat transfer coefficient on-orbit was 10%−29% lower than the ground result. The research would contribute to the theoretical basis of two-phase flow and heat transfer and promote the development of active two-phase thermal control technology for space.