A highly self-adaptive cold plate for the single-phase mechanically pumped fluid loop for spacecraft thermal management

Abstract

Aiming to improve the conventional single-phase mechanically pumped fluid loop applied in spacecraft thermal control system, a novel actively-pumped loop using distributed thermal control strategy was proposed. The flow control system for each branch consists primarily of a thermal control valve integrated with a paraffin-based actuator residing in the front part of each corresponding cold plate, where both coolant’s flow rate and the cold plate’s heat removal capability are well controlled sensitively according to the heat loaded upon the cold plate due to a conversion between thermal and mechanical energies. The operating economy enhances remarkably owing to no energy consumption in flow control process. Additionally, realizing the integration of the sensor, controller and actuator systems, it simplifies structure of the traditional mechanically pumped fluid loop as well. Revolving this novel scheme, mathematical model regarding design process of the highly specialized cold plate was entrenched theoretically. A validating system as a prototype was established on the basis of the design method and the scheduled objective of the controlled temperature (43°C). Then temperature control performances of the highly self-adaptive cold plate under various operating conditions were tested experimentally. During almost all experiments, the controlled temperature remains within a range of ±2°C around the set-point. Conclusions can be drawn that this self-driven control system is stable with sufficient fast transient responses and sufficient small steady-state errors.