Study On Thermal Analysis And High-precision Temperature Control Of Triple-channel Optical Filter

ABSTRACT:Triple channel birefringent optical filter is the major instruments in research of solar physics. The refractive index of crystal material in optical filter is sensitive to temperature, so the optical filter has to work in the 315.15K constant temperature environment.The temperature control accuracy of the most thick ice spar-grade should be under 0.01K. The temperature difference of internal crystal in triple-channel optical filter must be less than 0.15K.In this thesis, the thermal of the triple-channel optical filter is analyzed in ANSYS. The results of thermal analysis provide guidance for the structural and temperature control design of optical filter. And the core circuit of the temperature control system is designed based on ARM7 MCU. The main research results of this thesis are as follows:1. The model of triple-channel optical filter in ANSYS is simplified and verified, which is helpful to create full and reasonable element model of thriple-channel optical filter in ANSYS.2. The effection of environmental conditions on temperature distribution of crystal is analysed. The temperature control system has to adjust heating power to different environmental conditions. And heating power influences the precision of temperature distribution on crystal.3. The results of thermal analysis provide guidance for thermal structural and temperature control system design of the triple-channel optical filter. The improvement strategies are analysed and verified. Among them, the strategy of thermostatic insulation glass can improves the temperature accuracy by 0.037K to 0.16K, which can satify optical filter work condition.4. The problems in current temperature control system and solution are analyzed. The core circuit of improved PID temperature control system is implemented based on ARM7. And the temperature information is sent to PC by UART. And the front panel of LabVIEW software in PC can display filters temperature in real-time. Experiments shows that the precision of improved temperature control system is 0.015K.