ＫＬＢ－３混合制冷剂替代Ｒ５０２的试验，在试验型鼓风式平板冻结装置上进行。通过对这两种制冷剂分别在同一台制冷压缩机组上运行，不调换热力膨胀阀和冷冻机油，测量压缩机的吸排气压力、输入功率、记录冻盘中一定量纯水的降温情况、以及冻结到－１８℃所需时间，观察机组运行情况。从试验情况可看出ＫＬＢ－３混合制冷剂替代Ｒ５０２是可行的。 The test of KLB-3 mixed refrigerant instead of R502 was carried out on a pilot-type blast-type flat plate freezing apparatus. The two refrigerants are respectively operated on the same refrigeration compressor unit, the thermal expansion valve and the refrigerating machine oil are not exchanged, the pressure of the suction and exhaust of the compressor is measured, the input power is recorded, and a certain amount of pure water in the freezing plate is cooled down, And the time required to freeze to -18 ℃, observe the unit operation. It can be seen from the test results that KLB-3 mixed refrigerant is feasible to replace R502.