A multipurpose test-bed for inverse Brayton air refrigerator was rebuilt

in which the experiments were executed on the two key parts of the system

the turbo expander and the compact heat exchanger. The thermodynamic performances of efficiency

temperature drop characteristics

flow resistance

and refrigeration effect

etc. were analyzed thoroughly under design conditions

and examinations were done under overworking conditions. The test results show that the refrigeration capacity of this refrigerator is -73 ℃(with the cooling load of 250 W)～-120 ℃(with the cooling load of 50 W)

the maximum temperature difference between system inlet and expander outlet is 150 ℃

and the expander efficiency can reach 60.5% while the heat exchanger efficiency reaches 97.5%. The minimum temperature of the system reaches -123 ℃

which meets the requirement of heat load of 5 W at -120 ℃. Through the test and analysis

the parameters influence relation and the parameters matching relation in high speed small turbo-expanders and compact heat exchangers are obtained.