Study on the coupling performance of a turboexpander compressor applied in cryogenic reverse Brayton air refrigerator

•Numerical simulations on expansion and compression processes were carried out.•A coupling model was built based on analysis and simulation and verified by test.•Relations and interactions among coupling parameters were quantitatively described.•When T0C=0.39MPa, the cooling capacity of refrigerator reached 221W at 129.6K.