Development Of Large-capacity High-temperature Thermostat Bath With High Accuracy And Saturated Vapor Pressure Apparatus And Research Of Vapor Pressure Equation Of Low GWP Refrigerant HFO-1234Yf

The testing and research work of thermal property data has always been the hot spots and focus for global researchers of thermal property.In recent years,the energy crisis and greenhouse effect increasingly attracted the attention of people, and set off a new round of research of clean fuels and alternative refrigeranst.And the practical application of new refrigerant needs a large number of reliable thermal property data.In this context, the task group decided to set up the laboratory of thermal properties to carry out the research of thermal properties. The thermostat bath,as one of the most important components of the fluid thermal property experiment system, will directly determine the quality of thermal property data and the whole system. As part of the initial stage of the lab building, a thermostat bath used for thermal property experiment was developed in this paper. Saturated vapor pressure, as one of the most basic thermal property data, plays a decisive role in the fields of metallurgy, chemistry, electronics, aerospace and medicine.Therefore,a saturated vapor pressure experiment apparatus was developed in this paper.Saturated vapor pressure and vapor pressure equation of HFO-1234yf was also studied in this work.A large-capacity,high-temperature thermostat bath with high accuracy was developed, its main features are:1) large volume(600mm×560mm×585mm).2)High precision. The temperature fluctuation is5.0mK, and the temperature uniformity is4.5mK, which satisfies the need of the thermal property experiment.3)Reasonable structure and design.The design of tank cover with foldings makes it easier to disassemble and repair the thermostat bath; The design of tank lid with insulation reduces the heat loss of the thermostat bath,lays the foundation of the improvement of the accuracy; the design of double glass windows overcomes the shortcomings of traditional windows(poor sealing and large amount of heat radiation); the design of U-type quartz heaters improves the heat transfer performance and service life of heaters; the design of cylindrical cover lid makes it more convenient to install heaters and stirrers.A saturated vapor pressure experiment apparatus was developed, The design pressure and temperature are15MPa and300℃respectively; the maximum working pressure and temperature are10MPa and250℃,respectively.A small raising platform special for the apparatus was developed, and it was used to change the height of apparatus in the thermostat bath.Saturated vapor pressure and vapor pressure equation of HFO-1234yf was studied.Based on all available experimental data,a Wagner type vapor pressure equation with four items was obtained.This equation has high accuracy, excellent extrapolation,and wide temperature range,which is superior to the existing HFO-1234yf vapor pressure equation,and has high practical value.