Performance prediction of a distributed Joule-Thomson effect cooler with pillars

Hampson type Joule-Thomson (J-T) throttle coolers are widely used for cooling infrared detectors and many electronic components. The conventional J-T throttle coolers are not compact, with low heat transfer efficiency and small cooling capacity. In this paper, a stacked column cluster type microchannel distributed J-T throttle cooler is designed through combining a compact microchannel etched and shaped by photolithography and an atomic diffusion fusion welding process with a J-T throttle cooler. The dimensions of the cooler are 10 mm for the inlet section, 145 mm for the throttling and heat exchange section, 10 mm for the expansion chamber, with 6 layers staggered high pressure channels and 6 low pressure channels. The cooling performance of the cooler under various low-temperature and high-pressure operating conditions were studied through simulations, and the results showed that the cold-end temperatures were 158.0, 147.9, 146.1, 144.1, and 141.1 K for an inlet pressure of 5.20 MPa and inlet temperatures of 280.0, 270.0, 260.0, 250.0, and 240.0 K, respectively, with argon as the work gas. The cold-end temperatures were 163.6, 159.4, 156.8, 154.6, and 152.7 K for an inlet pressure of 5.60, 6.00, 6.40, 6.80, and 7.20 MPa respectively in 288.0 K inlet temperature. In the process of working medium flow and heat transfer in the microcolumn group channel of the cooler, the temperature and pressure change significantly. When the working medium in the flow reaches the phase change state, that is, the phase change temperature and pressure reach, due to the gas liquefies and the flow rate drops, the working medium loses the gas throttling refrigeration effect, and the temperature no longer decreases significantly, and the refrigeration temperature is limited by this. In addition, compared with different inlet pressures, when the inlet temperature is 280.0 K, the 5.20 MPa nitrogen throttling refrigeration temperature is close to the argon gas at 2.98 MPa, which are 223.4 K and 234.9 K, respectively. Therefore, high pressure nitrogen can be considered to replace low pressure argon in engineering applications. In view of the problems involved in the research process of traditional micro-channel throttling coolers, the innovative solutions are put forward in this paper, which can bring new innovations and thoughts for the future research and application of such problems.