A multilayer micro-channel Joule-Thomson (J-T) cryocooler was designed by combining several layers of rectangular micro-channels with a coke soup cooler. The heat recovery section was constructed using three layers of high- and low-voltage rectangular channels. Experiments were conducted using nitrogen as a refrigerant with inlet pressures ranging from 4 to 8 MPa

and the temperatures of each of the measuring points of the multi-layer microchannels in the J-T cryocooler were collected. The cooling characteristics of nitrogen in the various stages of the refrigeration system were analyzed

and the experimental results obtained when nitrogen and argon were used in the J-T cryocooler were compared. The results show that

when the inlet pressure is 4-8 MPa

a lower temperature for the nitrogen cold end with increasing pressure corresponds to a shorter time period to reach a stable cold-end temperature. When the inlet pressure is 8 MPa

the cold-end temperature reaches 1.7 ℃ at approximately 200 s. The argon cold-end temperature is lower than that of the nitrogen at the same inlet pressure; however

the time required for the nitrogen to reach the cold-end temperature is shorter than that for the argon. When the inlet pressure is 7 MPa

the temperature of the cold-end argon gas occurs approximately 450 s ahead of time. Further

the temperature drops for nitrogen at an 8-MPA inlet pressure and argon at a 4-5 MPa inlet pressure are similar. In addition

the nitrogen cooling time is shorter. Thus

the use of nitrogen instead of argon can reduce the cooling costs.