火箭推进

氦氙气体的组分保持是氦氙布雷顿能量转换系统长期稳定运行的基础,而无论是工质气体的泄漏还是充填量的调节都有可能导致系统中的氦氙气体组分发生变化,进而影响系统运行状态。通过对氦氙布雷顿系统的动态仿真计算,得到了气体组分发生变化时系统运行的差异。当气体组分发生变化时,系统共同工作线将发生偏移,尤其是气体摩尔质量变小时,共同工作线向喘振线偏移; 并且在到达满功率输出时,压气机喘振裕度变小,且需要更高的涡轮入口温度; 同时会导致回热器热侧温度入口提高,不利于系统的稳定运行。基于系统仿真结果提出了在额定转速下以负荷率、流量为变量的氦氙气体组分计算方法,为实现氦氙布雷顿循环工质组分变化的监控和调节提出了新思路。该方法中,流量的精确测量是提高组分分析精度的重要保障。

Gas composition maintenance of helium-xenon mixture is the basis for the long-term stable operation of the helium-xenon brayton energy conversion system. However, composition of the helium-xenon gas in the system may change because of working gas leakage or adjustment of filling amount, and then system operation status is affected. Through the dynamic simulation of the helium-xenon brayton system, the difference of the system operation status was obtained with the condition of the gas composition changing. When the gas composition changes, the common working line of the system will shift, especially when the gas molar mass becomes smaller, the common working line will shift to compressor surge line; and when the full power output is reached, the surge margin of the compressor will be smaller and higher inlet temperature of turbine and recuperator is required, which is not conducive to the stable operation of the system. Based on the system simulation results, this paper proposed a calculation method of helium-xenon gas composition with load rate and flow rate as variables at rated speed and put forward a new idea for monitoring and adjusting the change of working fluid composition in helium-xenon Brayton cycle. In this method, accurate measurement of flow rate is an important guarantee to improve the precision of component analysis.

引言
1 计算模型
2 不同气体组分运行特性
3 气体组分表征方法
4 结论

图1 闭式布雷顿循环动态仿真模型<br/>Fig.1 Dynamic simulation model of closed Brayton cycle

图1 闭式布雷顿循环动态仿真模型
Fig.1 Dynamic simulation model of closed Brayton cycle

图2 计算流程
Fig.2 Calculation process

图3 不同气体组分下的系统启动加载曲线<br/>Fig.3 System startup-loading curves under different gas compositions

图3 不同气体组分下的系统启动加载曲线
Fig.3 System startup-loading curves under different gas compositions

图4 不同工质加载过程对比<br/>Fig.4 Comparison of loading processes with different working fluid

图4 不同工质加载过程对比
Fig.4 Comparison of loading processes with different working fluid

表1 不同工质加载始末的压气机喘振裕度及满载时涡轮温度<br/>Tab.1 Compressor surge margin and turbine temperature during loading process with different working fluids

表1 不同工质加载始末的压气机喘振裕度及满载时涡轮温度
Tab.1 Compressor surge margin and turbine temperature during loading process with different working fluids

图5 不同组分气体在不同负荷率下的回热器热侧入口温度<br/>Fig.5 The inlet temperature of the hot side of the regenerator with different gas components under different load rates

图5 不同组分气体在不同负荷率下的回热器热侧入口温度
Fig.5 The inlet temperature of the hot side of the regenerator with different gas components under different load rates

表2 不同组分工质不同负荷率下的系统流量、压比参数(相对值)<br/>Tab.2 System flow rate and pressure ratio with different components of working fluid and load rates(relative value)

表2 不同组分工质不同负荷率下的系统流量、压比参数(相对值)
Tab.2 System flow rate and pressure ratio with different components of working fluid and load rates(relative value)

表3 拟合公式(1)中的参数值<br/>Tab.3 Parameter values in the fitting formula(1)

表3 拟合公式(1)中的参数值
Tab.3 Parameter values in the fitting formula(1)

表4 氦氙摩尔质量计算结果<br/>Tab.4 Molar mass calculation results of helium xenon mixture

表4 氦氙摩尔质量计算结果
Tab.4 Molar mass calculation results of helium xenon mixture

[1] 胡古,赵守智.空间核反应堆电源技术概览[J].深空探测学报,2017,4(5):430-443.
[2] RITZ F,PETERSON C E.Multi-mission radioisotope thermoelectric generator(MMRTG)program overview[C]//2004 IEEE Aerospace Conference Proceedings.New York:IEEE,2004.
[3] WERNER J,LIVELY K,KIRKHAM D.A multi-mission radioisotope thermoelectric generator(MMRTG)for Mars 2020[C]//2017 IEEE Aerospace Conference.New York:IEEE,2017.
[4] VOSS S S,RODRIGUEZ E A,EL-GENK M S,et al.Russian TOPAZ II system test program(1970—1989)[C]//AIP Conference Proceedings.Albuquerque,New Mexico:AIP,1994.
[5] PONOMAREV-STEPNOI N N,KUKHARKIN N E,USOV V A.“Romashka” reactor-converter[J].Atomic Energy,2000,88(3):178-183.
[6] ROSEN R,SCHNYER A D.Civilian uses of nuclear reactors in space[J].Science & Global Security,1989,1(1/2):147-164.
[7] STANCULESCU A.The role of nuclear power and nuclear propulsion in the peaceful exploration of space[M].Vienna:International Atomic Energy Agency,2005.
[8] KOROTEEV A S,ANDIANOV D I,KAREVSKIY V,et al.Test bench for key components of megawatt class international power and propulsion system ground demonstration[C]//7th European Conference for Aeronautics and Space Sciences.Milan,Italy:[s.n.],2017.
[9] BARNETT J W.Nuclear electric propulsion technologies:Overview of the NASA/DOE/DOD nuclear electric propulsion workshop[C]//AIP Conference Proceedings.Albuquerque,New Mexico:AIP,1991.
[10] OLSON S.Mars opposition piloted nuclear electric propulsion(NEP)-chem vehicle[Z].2020.
[11] DATAS A,MARTÍ A.Thermophotovoltaic energy in space applications:Review and future potential[J].Solar Energy Materials and Solar Cells,2017,161:285-296.
[12] MASON L S.A comparison of Brayton and Stirling space nuclear power systems for power levels from 1 kilowatt to 10 megawatts[C]//AIP Conference Proceedings.Albuquerque,New Mexico:AIP,2001.
[13] TORO C,LIOR N.Analysis and comparison of solar-heat driven Stirling,Brayton and Rankine cycles for space power generation[J].Energy,2017,120:549-564.
[14] OLUMAYEGUN O,WANG M H,KELSALL G.Closed-cycle gas turbine for power generation:A state-of-the-art review[J].Fuel,2016,180:694-717.
[15] 郭凯伦,王成龙,秋穗正,等.兆瓦级核电推进系统布雷顿循环热电转换特性分析[J].原子能科学技术,2019,53(1):16-23.
[16] TOURNIER J M,EL-GENK M,GALLO B.Best estimates of binary gas mixtures properties for closed brayton cycle space applications[C]//4th International Energy Conversion Engineering Conference and Exhibit(IECEC).Reston,Virginia:AIAA,2006.
[17] MASON L,SCHREIBER J.A historical review of brayton and stirling power conversion technologies for space applications[EB/OL].https://www.semanticscholar.org/paper/A-Historical-Review-of-Brayton-and-Stirling-Power-Mason-Schreiber/2fbcbd6db6c38452944eacda9b22cf4f240b7
[18] MASON L S.A power conversion concept for the Jupiter icy moons orbiter[J].Journal of Propulsion and Power,2004,20(5):902-910.
[19] MASON L S.Power conversion concept designed for the Jupiter icy moons orbiter[R].NASA 20050192432.
[20] 王浩明,薛翔,张银勇,等.空间闭式布雷顿循环旁路调节特性分析[J].火箭推进,2021,47(2):61-67.
[21] 薛翔,杜磊,王浩明,等.闭式布雷顿循环核心机调控过程仿真分析[J].火箭推进,2021,47(5):49-55.

备注

引言

1 计算模型

2 不同气体组分运行特性

3 气体组分表征方法

4 结论

期刊信息