【摘要】 采用不锈钢为材料以金属蚀刻芯片和真空扩散焊接工艺制成了芯片型节流制冷器,搭建了微型节流制冷器系统,以高压氮气和氩气为工质,研究了不同入口压力下无负荷节流的制冷温度和流量特性。实验结果表明:采用氮气为工质时,在入口压力为10.5 MPa工况下,最低制冷温度为102.9 K;采用氩气为工质时,在压力为8.6 MPa工况下可获得112.0 K的最低制冷温度,降温速度也有效提升。在大流量下,低压通道阻力增大将导致节流后背压和蒸发温度提高,采用氮气和氩气作为工质在压力分别高于10.5 MPa和8.6 MPa时,制冷温度开始回升。验证了基于金属微通道蚀刻工艺技术的芯片型节流制冷器可行性,表明采用金属微流道芯片可以大幅提高耐压能力、机械强度和降温速率。更多还原

【Abstract】 A microminiature Joule-Thomson(J-T) refrigerator is developed by using vacuum diffusion welding of stainless-steel microchannel chips. The zero-load refrigeration temperature and flow rate were obtained under different inlet pressures were studied by using high-pressure nitrogen and argon as working fluids. The experimental results show that when nitrogen was used as the working fluid, the minimum refrigeration temperature was 102. 9 K at the inlet pressure of 10.5 MPa. When argon was used as the working fluid, the cooling-down rate could be effectively increased, and the lowest refrigeration temperature of 112. 0 K could be obtained under the inlet pressure of 8. 6 MPa. At large flow rate, the pressure after throttling and evaporation temperature increased due to the increased flow resistance of the low-pressure channel. Using nitrogen and argon as working fluids, the refrigeration temperature started to rise when the pressure was higher than 10. 5 MPa and 8. 6 MPa, respectively. This study demonstrates the feasibility of the microminiature J-T refrigerator based on metal microchannel technology. The use of metallic microchannel chip can help enhanced the failure pressure, mechanical strength and cooling-down rate.更多还原