Experimental Investigation Of CO₂Refrigeration Based On Joule-Thompson Effect

As the storage of the energy and natural resources becoming less and less, the whole world is facing significantly serious energy crisis. As a mature refrigeration method, the Joule-Thompson effect has been widely used in many areas, such as natural gas transmission, low-temperature electronic technology, infrared technique and cryosurgery. The Joule-Thompson effect can improve the energy efficiency by using pressure energy.Based on Joule-Thompson effect, a new type J-T cooler which uses carbon dioxide as coolant has been designed. The J-T cooler includes throttling element and heat exchange system. The throttling element can be replaced according to the need of the experiment. In order to measure refrigerating capacity, circulation water passage and fins have been fabricated in the heat exchange system. An experiment system is set up for testing the cooling performance of J-T cooler by changing the throttling element and adjusting the entrance pressure, with carbon dioxide as the coolant. It turns out that as orifice size gets smaller, the outlet temperature of throttling element will get lower and the temperature decreasing rate will get higher. Besides that, when the inlet pressure of throttling element gets higher, temperature decreasing rate will get higher considerably. Compared with the inlet pressure is2MPa, when the pressure is6MPa, the maximum temperature decreasing rate of three different throttling elements is11.25times,6.91times and3.91times. It also turns out that cooling efficiency can be improved and cooling time can be decreased by decreasing the orifice size or increasing the inlet pressure.