Precision Thermal Control Scheme of Fluctuating Temperature for Space Fluid Loop
Hanze ZHANG, Tong ZHENG, H.G. Zhang, Bo CHEN · Chinese Journal of Space Science · 2019
Fluid temperature at the inlet branches of the space fluid loop fluctuates randomly within a specific range, therefore measures should be taken to decrease their thermal effects on cold-plate cooled high-stability requirement payloads. Because the traditional patch heaters require additional power and produce waste heat, a scheme of fluid mixing with PID controlled valves is proposed, which can utilize thermal energies in different loop braches to control the temperature at the coldplate inlet by regulating valve openings. A numerical study is performed and its results show the system can satisfy the high precision temperature control requirement. The fuzzy PID control effect is better than that of the PID control algorithm, such as faster response, less overshoot, and higher control precision. Therefore, the fuzzy PID is preferred as the control algorithm of this scheme.