Thermal analysis of the high sensitivity terahertz detection module under different operating modes of the evaporator

• Proposes hybrid thermal management for high sensitivity terahertz module ensuring temperature stability. • Develops thermal simulation method based on temperature-controlled boundaries. • Discusses the redundant thermal design analysis and its experimental validation strategy. • Verifies extreme thermal scenarios via mode screening showing 2.2°C experiment-simulation deviation. • Identifies the recommended in-orbit operational mode via systematic analysis. This paper presents a systematic thermal design of the terahertz detection module and analyzes the evaporator's operational modes. A comparative thermal analysis was performed across three modes, with the most extreme condition selected for thermal balance test and a more stable mode designated for default in-orbit operation. Simulation results indicate that when evaporators 1 and 2 are operating and evaporator 3 is disconnected (referred to as Mode 3), the internal components of the terahertz detection module experience a significant temperature rise, particularly with the compressor having only a 4.3°C temperature margin. Thermal balance tests confirmed the effectiveness and reliability of the thermal design, with a 2.2°C deviation between the experiment and simulation. In contrast, when evaporators 1 and 3 are operating and evaporator 2 is disconnected (referred to as Mode 2), the internal components remain at relatively low temperatures, especially with the cold finger of the cryostat at only 9.6°C, the lowest among the three modes, making this mode the preferred choice for in-orbit operations. The thermal design and redundant thermal strategies proposed in this study not only ensure the safe operation of the terahertz detection module in orbit but also provide valuable insights and theoretical foundations for the thermal control design of other space exploration systems.