空间流体回路单点恒温控制方案

空间流体回路的载荷支路来流温度在一定范围内随机变化，需采取有效热控措施消除来流温度变化对回路单点位置处恒温工作载荷的热影响.传统电加热方式需要额外能耗并且会产生废热，本文提出一个PID控制下的冷热回路交混控温方案，在充分利用工质吸收的废热、提高机柜内能源利用率的同时，实现对恒温设备冷板入口温度的精确控制，以满足冷板上载荷的恒温工作需求；设计流体回路组成与控制方案，并通过仿真分析对方案进行了验证.结果表明，该流体回路系统可以满足对来流温度的高精度控制要求，且相比于PID控制算法，模糊PID的控制效果更好，具有响应快、超调量小、控制精度高等特点，应优先选择模糊PID作为控制算法. 

Precision Thermal Control Scheme of Fluctuating Temperature for Space Fluid Loop

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.