基于AMESim的液氮可控传输性能分析

针对超低温冷却加工液氮可控传输难题,分析了热流量、管路压降等复杂因素对液氮可控传输的影响机制,提出了基于AMESim的液氮可控传输性能分析方法,建立了受热管道液氮两相流动传热数值模型,并在此基础上,研制出一套液氮可控传输原理性系统。通过对比实验表明,提高系统的输入压力能够增大低温流体的流量,缩短系统进入热平衡状态的时间,提高输出流体的干度和流型的稳定性;研制出的液氮可控传输原理性系统在输入压力为1.3 MPa时,在一定的开口范围内,能够稳定输出流量可控的低干度流体,且符合超低温冷却加工的要求。

Analysis on controllable transmission performance of liquid nitrogen based on AMESim

In order to solve the transmission problem of liquid nitrogen for cryogenic machining,the effects of heat flux and pressure drop on the controllable transfer of liquid nitrogen were analyzed.Based on AMESim,a method for analyzing the performance of liquid nitrogen controllable transmission was proposed and a numerical simulation model of heat transfer of liquid nitrogen two-phase flow in heated pipes was established.Based on the analysis and the model,a set of controllable transmission system of liquid nitrogen was developed.Experiment results showed that increasing the input pressure of the system can increase the flow rate of the cryogenic fluid,shorten the time for the system to enter the thermal equilibrium state,and improve the dryness of the output fluid and the stability of the flow pattern.When the input pressure is 1.3Map,the developed liquid nitrogen controllable transmission system can stably control the flow rate of the fluid with low dryness,and meet the requirements of cryogenic machining process.