一种碘工质电推进贮供系统工作特性研究

Operational Characteristics of an Iodine Propellant Feed System for Electric Propulsion

本文以碘工质电推进贮供系统为研究对象。比较了以往设计方案的优缺点,提出了一种碘贮罐粗调压,Bang-Bang控制器精调压,热节流管精确限流的设计方案。采用AMESim软件对该方案进行了仿真分析,对比了实验数据和模拟结果。研究了热节流管入口压力和热节流管内气态碘温度对输出气态碘流量的影响。分析了Bang-Bang控制器和热节流管的工作特性以及碘贮罐温度对输出气态碘流量的影响。结果表明:在0.2 mg/s-3mg/s的气态碘流量范围内,为实现±10%的控制精度,热节流管入口压力误差需≤±50 Pa或气态碘温度误差需≤±15 K;通过改变Bang-Bang控制器的压力控制上下限能够有效控制热节流管的输出流量,实现气态碘流量在0.2 mg/s-3mg/s的非连续变化,且大部分流量波动在±10%之间。碘贮罐温度变化±5 K时,输出气态碘质量流量误差仍小于±10%。研究结果说明该设计方案可明显降低碘贮罐温度控制难度,提高输出气态碘流量精度。

The paper aims to study an iodine propellant feed system for electric propulsion.Firstly,comparisons of different previous design schemes are carried out,and a design scheme consisting of an iodine reservoir,a Bang-Bang controller,and a thermal throttle is proposed.Then,a simulation model is established using AMESim software to describe the design scheme,and the simulation results and the experimental data are compared.Finally,the effects of the inlet pressure of the thermal throttle and the temperature of the gaseous iodine in the thermal throttle on the flow rate of the gaseous iodine are studied.The operational performance of the Bang-Bang controller and the thermal throttle,and the effect of temperature in the iodine reservoir are analyzed.The results show that if the output flow rate of the gaseous iodine is 0.2 mg/s−3 mg/s with an error of±10%,the inlet pressure error of the thermal throttle must be±50 Pa,or the temperature error of the gaseous iodine must be±15 K;if the high and low threshold pressures of the Bang-Bang controller are changed,the flow rate of the gaseous iodine can be various from 0.2 mg/s to 3 mg/s discontinuously,and the errors of the most output flow rate of the gaseous iodine are less than±10%.In addition,the output flow rate has an accuracy of±10%when the temperature change in the iodine reservoir is±5 K.It is indicated that the design scheme can reduce the difficulty of temperature control in the iodine reservoir and further improve the accuracy of the output flow rate of the gaseous iodine.