两相控温型储液器进出流量的瞬态数值模拟

两相控温型储液器是泵驱两相流体回路（MPTL）系统中的一个重要部件，承担着工质存储、供给、气液分离及精密控温的作用。采用Navier-Stokes方程建立了MPTL系统瞬态模拟的仿真模型，可用于研究热源功率变化时储液器与主回路的动态传热和传质特性。通过仿真与试验对比发现，数值模型的流量误差在±10%以内，验证了模型的有效性和准确度。数值模拟结果表明:热源开关机时，储液器与主回路发生工质交换，气液两相的温度和压力受到影响，系统的流阻也受到影响；随着热源功率的增加，工质交换速率和交换总量随之增加，储液器内气液两相的温度和压力变化趋势随之增大。该模型可用于研究不同工作条件下的流量、温度和干度的变化特性，指导MPTL设计，并在系统搭建前预测系统特性。 

Transient numerical simulations of flow rate into and out of two-phase temperature control accumulator

Two-phase temperature control accumulator (hereinafter referred to as accumulator) is the key component of mechanically pumped two-phase loop (MPTL) system, which acts like the brain of MPTL system. The accumulator has the functions of storage and supplying of working fluid, gas-liquid separation and precise temperature controlling. In order to study the dynamic behavior of heat and mass transfer between accumulator and MPTL system in response to heat load variations, a transient numerical simulation model is developed for MPTL system by using the Navier-Stokes equations. By comparison between simulation and test results, it is found that the flow rate error of numerical model is in the range of ±10%, which verifies the validity and accuracy of the model. The simulation results show that accumulator will exchange fluid with the main loop in response to heat load variations. In this case, the temperature and pressure of two-phase fluid in accumulator, and the total system flow resistance will be affected. The rate and amount of mass transfer between accumulator and main loop will increase with the increase of heat power, and the same increase will occur for the variation trend of temperature and pressure of two-phase fluid in the accumulator. The model can be used to study the variation characteristics of flow rate, temperature, and quality under different operating conditions, which can also be used to design MPTL system and to predict the system characteristics before a system has been built.