基于TEC的空间站末端回路温控系统建模及其热力学性能分析

针对空间站中间回路温度波动过大,高温时导致科学载荷工作温度超出允许范围的问题,设计了一种基于热电制冷器(TEC)的末端单向流体回路温控系统。该系统包含一个TEC温控模块,当中间回路温度过高,末端回路冷却功率不足时,该模块可提供额外的制冷量,降低流入冷板的工质温度,形成针对科学载荷的相对低温区域,恢复回路的冷却能力。分别建立了温控系统数学模型与数值仿真模型,并完成了热负载扰动、中间回路温度扰动、末端回路流量扰动和并联支路热扰动等4种扰动对系统热力学特性影响的仿真分析,验证了TEC模块的温控性能。结果表明:在科学载荷发热功率增加30%、中间回路的温度升高5K、末端回路流量减小至0.0015kg/s等多种工况下,所设计的温控系统能够将载荷温度控制在1K以内,实现科学载荷精确温控。 

Modeling and thermodynamic performance analysis of thermal control system based on terminal circuit with TEC in space station

A thermal control system was designed based on terminal single phase fluid circuit with thermoelectric cooler (TEC), which was capable of solving the problem of overranging temperature of science loads, when the intermediate circuit temperature fluctuated greatly. A thermal control module based on TEC was presented for improving the cooling ability of the fluid circuit, to recover its cooling capacity. Extra cooling power was provided to lower the working fluid temperature of inlet flows through the cold plate, providing a relative lower temperature region around science load, when the fluid circuit power was insufficient because of the high temperature of the intermediate circuit flow. Moreover, a mathematical model and a numerical simulation model were established separately for the proposed thermal control system. Furthermore, the thermal control performance of the TEC module was verified in the cases of four thermal disturbances, such as heat load disturbance of science load, temperature disturbance of the intermediate circuit, mass flow rate disturbance of the terminal circuit, and heat disturbance of parallel branches. Simulation work shows that: the designed thermal control system keeps the temperature fluctuation margin of science load below 1K for strict cooling requirement, in several conditions such as: science load heating power increase by 30%, intermediate circuit temperature increase by 5K, terminal circuit mass flow rate decrease to 0.0015kg/s.