基于半导体制冷预冷的氮气冷冻刀系统实验研究

Experimental study of nitrogen cryoprobe system based on semiconductor refrigeration pre-cooling

设计了基于三级半导体制冷的氮气J-T效应预冷器,研制了直径3 mm的冷冻探针,搭建了基于半导体制冷预冷的氮气冷冻刀降温实验系统。实验结果表明,本系统中冷冻刀在氮气初始压力8.5 MPa下节流温度可达-98.3℃,在初始压力为12 MPa下,节流后的氮气最低温度可达-120℃;冷冻刀的冷量随刀头恒定制冷温度的不同而不同,在氮气初始压力为8.5 MPa下,其制冷温度恒定为-47℃时,冷量为30 W,可满足杀死细胞的要求;水中冻结实验表明,氮气初始压力越大,冷冻刀冷量越大。

The nitrogen J-T effect pre-eooler was designed based on three-level semiconductor refrigera- tion, the cryoprobe of 3 mm diameter was developed and the nitrogen cryoprobe cooling system was set up based on the semiconductor pre-cooler. The experimental results showed that under the initial pressure of 8.5 MPa, the throttle temperature of the cryoprobe could reach to - 98.3 ℃. While under the initial pres- sure of 12 MPa, the throttle temperature of nitrogen could reach to -120 ℃. The cooling capacity of the cryoprobe was different when the constant refrigeration temperature changed. Under the pressure of 8.5 MPa, the cooling capacity was 30 W when the constant refrigeration temperature was -47 ℃ , meeting the requirements of killing cells. Freezing experiment in water also indicated that the cooling capacity increased with the increase of the initial pressure of the nitrogen.