The multi-channel scanning imager is one of the main payloads of a Geostationary earth orbit satellite of China,
which observe multi spectrum from earth. Passive thermal control was applied to decrease temperature rise when solar
intrusion at midnight, and heat compensation was made to decrease thermal fluctuation in one orbit. Effort was focused
on the scanning mechanism for its relatively strict temperature gradient requirement. In order to validate thermal control
scheme, thermal balance experiment scheme was planned. Considering the complexity of solar heat flux into sunshade,
solar simulator was used to precisely simulate the heat flux variation. Limited to the dimension of vacuum chamber and
solar simulator lamp, only the flux into sunshade was simulated by solar simulator, and other parts was simulated by
electrical heaters. The solar illuminated region was analysed in order to keep the total heat flux correct. Detailed test
process was figured out to carry out two kinds of heat flux simulation. Date were acquired and compared to thermal
analysis. Based on experiment condition, thermal model was constructed and modified. From analysis of all the effecting
factors, it is find that thermal contact resistance between heatpipes and heat dissipating plate can largely effect the
temperature of scanning mechanism. Thermal model of scanning mechanism was detailly constructed including features
effecting heat flux absorption and temperature distribution. After modification, the prediction ability of thermal model
was enhanced. And optimization of thermal design was made to decrease temperature level and gradient of scanning
mechanism. Thermal analyse was done to estimate the optimization, and its effectiveness was validated.
Conventional passive thermal design failed to satisfy CCD’s temperature requirement on a geostationary earth orbit satellite Imager camera because of the high power and low working temperature, leading to utilization of thermoelectric cooler (TEC) for heat dissipation. TEC was used in conjunction with the external radiator in the CCDs’ thermal design. In order to maintain the CCDs at low working temperature, experimental research on the performance of thermoelectric cooler was necessary and the results could be the guide for the application of TEC in different conditions. The experimental system to evaluate the performance of TEC was designed and built, consisting of TEC, heat pipe, TEC mounting plate, radiator and heater. A series of TEC performance tests were conducted for domestic and oversea TECs in thermal vacuum environment. The effects of TEC’s mounting, input power and heat load on the temperature difference of TEC’s cold and hot face were explored. Results demonstrated that the temperature difference of TEC’s cold and hot face was slightly increased when TEC’s operating voltage reached 80% of rating voltage, which caused the temperature rise of TEC’s hot face. It recommended TEC to operate at low voltage. Based on experiment results, thermal analysis indicated that the temperature difference of TEC’s cold and hot face could satisfy the temperature requirement and still had surplus.
The multi channel scanning imagery radiometer is one of the main payloads of a geostationary earth orbit satellite , which can observe multi spectrum from the earth. The radiometer will endure complicated heat flux environment in orbit, and effective thermal design for the instrument is required in order to ensure high quality scanning image. Based on characteristics of the heat flux in geostationary earth orbit and the unique structure of the radiometer, thermal design characteristic was analyzed, and detailed thermal control design was developed based on numerical analysis. The numerical results verified the validity of thermal control design.