Research on control technologies for ultra-low dew point temperature and carbon dioxide concentration in large-scale test chambers

For the large-scale environmental test chamber in some special fields, it is necessary to simulate an extremely dry and purified environment with a dew point temperature lower than -60 ℃ and a carbon dioxide volume fraction less than 10×10-6 to ensure the testing effect of special tests. Based on the actual project, this paper discusses the technical measures and difficulties in realizing the environment with ultra-low dew point temperature and carbon dioxide concentration through theoretical analysis, software simulation and test verification. Finally, an environmental control system is determined, which consists of the air compression module, the low-pressure adsorption module, the air conditioning module and the control module, and its workflow is presented. The field acceptance test results show that all indexes are satisfied and better than the user’s requirements. The atmospheric dew point temperature in the whole dry environmental chamber is lower than -60 ℃, the lowest dew point temperature reaches -62.68 ℃, and the carbon dioxide volume fraction is less than 5.2×10-6.