节流制冷对低温贮箱主流液体控温影响分析

Analysis of JT refrigeration influence on temperature control of mainstream liquid in cryogenic storage tank

为研究低温流体节流特性及冷量引入对贮箱主流体控温影响,首先对低温流体节流干度和体积含气率进行了分析,结果表明质量占比较小的气相占据了大部分空间体积,对流动速率及换热产生较大影响;建立了节流制冷性能测试平台,采用液氮工质开展了节流前压力为0.3~0.37 MPa工况下的减压降温试验,节流前后降温达到了11.3~14.2 K;在集成节流阀孔的热力学排气系统(TVS)系统中,通过节流制冷使贮箱流体产生了平均6.5 K的温降,将贮箱压力控制在150~160 kPa范围;冷量的引入使主流区液体温度持续波浪式降低,气液界面热分层处的降温效果更加明显。

In order to study the Joule Thomson(JT)characteristics of cryogenic liquid and the influence of the introduction of cooling capacity on the temperature control of the mainstream in tank,the mechanism of the throttling dryness and volume void fraction on the heat transfer of the fluid was analyzed, which showed that the gas with small mass occupied most of the space volume;The test platform of throttling performance was established,and the experiment of refrigeration was carried out with liquid nitrogen as the working medium when the pressure before throttle ranged from 0. 3-0. 37 MPa,the temperature drop reached 11. 3-14. 2 K. In the thermodynamic vent system(TVS),the average temperature drop of the fluid involved in throttling was 6. 5 K,and the tank pressure was controlled within 150-160 kPa. The introduction of cooling capacity made the temperature of mainstream decrease in a wavy trend,and the cooling effect at the thermal stratification of the gas-liquid interface was more obvious.