Low Temperature Refrigeration Research Of Saturated Gas Generator

With the humidity measurement technology widely application in industry filed, the research of high performance humidity generator becomes more and more important. The humidity generator with wide temperature range and large flow is composed of gas preparation subsystem, the saturated gas generation subsystem and experimental box subsystem, in which the low temperature refrigeration subsystem is designed in this paper to obtain saturated wet air though cooling the dry air flowed in the subsystem.The refrigeration method is determined and designed based on the analysis of humidity generator principle in and abroad, then the main components of the refrigeration system are selected and the detailed design of the refrigeration system is completed.The refrigeration system is a complicated nonlinear system, and its refrigerating performance will be influenced by many kinds of disturbance factors. Therefore, it is established simulation mathematical model of refrigeration system controller unit. On this basis, a control method combining inverter compressor frequency with electronic expansion valve based on variable universe fuzzy control principle is designed, and then simulation experiment has been done to prove good robustness of the controller. Finally, taking PAC platform of NI Corporation as foundation refrigeration system's data acquisition software is designed using LabVIEW language to verify the system performance under heavy load operating conditions.