Simulation of Thermodynamic Characteristics of Supercritical Carbon Dioxide Brayton Cycle System Based on Modelica
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摘要: Modelica是一种大型复杂系统建模的开源式面向对象语言,由瑞典的非盈利组织Modelica协会开发。本文对Modelica语言用于超临界二氧化碳布雷顿循环系统热力学特性仿真进行了探索。基于压缩机、透平、回热器和冷却器等关键设备的机理关系式,开发了基于Modelica语言的超临界二氧化碳模型库,基于可视化界面拖拽式建模构建了单级回热循环系统仿真模型,基于Modelica语言构建的平台Mworks的求解器进行了稳态求解。通过与SCTRAN/CO2计算结果对比,验证了Modelica模型的可靠性和Modelica语言用于超临界二氧化碳布雷顿循环系统热力学特性仿真的可行性,分析了单级回热循环的瞬态特性。Abstract: Modelica is an open-source object-oriented language for modeling large and complex systems, and developed by the Swedish non-profit organization Modelica Association. In this paper, Modelica language is used to simulate the thermodynamic characteristics of supercritical carbon dioxide Brayton cycle system. Based on the mechanism relationship of key equipment such as compressor, turbine, regenerator and cooler, a supercritical carbon dioxide model library based on Modelica language was developed. A simulation model of single-stage regenerative cycle system was built based on drag and drop modeling and visual interface. The steady-state solution was carried out based on the solver of Modelica platform Mworks. Compared with the calculation results of SCTRAN/CO2, the reliability of Modelica model and the feasibility of Modelica in the simulation of thermodynamic characteristics of supercritical carbon dioxide Brayton cycle system were verified, and the transient characteristics of single-stage regenerative cycle were analyzed.
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Key words:
- Modelica /
- Supercritical carbon dioxide /
- System simulation /
- Brayton cycle
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表 1 工况参数表
Table 1. Parameters of Simulated Condition
参数 数值 压缩机入口压力/MPa 8.1 压缩机入口温度/℃ 35 热源出口温度/℃ 600 热源功率/MW 10 系统流量/(kg·s−1) 72.9 压缩机转速/(r·min−1) 20000 透平转速/(r·min−1) 20000 表 2 Modelica模型和SCTRAN/CO2模型计算结果对比表
Table 2. Comparison of Calculation Results between Modelica and SCTRAN/CO2
设备 变量名称 SCTRAN/CO2 Modelica 相对
偏差/%压缩机 入口压力/MPa 8.1130 8.1000 0.16 入口温度/℃ 36.0745 35.0000 3.07 出口压力/MPa 18.1199 18.1000 0.11 出口温度/℃ 73.4624 70.4000 4.35 流量/(kg·s−1) 76.6841 74.4000 3.07 压比 2.2335 2.2346 0.06 效率 0.7402 0.7400 0.03 功率/MW 1.82 1.74 4.46 转速/(r·min−1) 20000 20000 0 热源 入口压力/MPa 18.1398 18.1000 0.22 入口温度/℃ 414.1485 416.9000 0.66 出口压力/MPa 17.9658 18.0000 0.19 出口温度/℃ 582.3000 600.0000 2.95 流量/(kg·s−1) 76.6841 74.4000 3.07 透平 出口压力/MPa 8.4761 8.4600 0.19 流量/(kg·s−1) 76.6841 74.4000 3.07 出口温度/℃ 498.6429 513.8000 2.95 压比 2.1272 2.1277 0.02 效率 0.8095 0.8100 0.06 功率/MW 7.13 7.20 1 转速/(r·min−1) 20000 20000 0 回热器热侧 出口压力/MPa 8.3166 8.3100 0.08 出口流量/(kg·s−1) 76.6841 74.4000 3.07 出口温度/℃ 80.7148 77.7000 3.88 冷却器热侧 入口压力/MPa 0.60 0.60 0 入口温度/℃ 31.00 31.00 0 出口压力/MPa 0.57 0.57 0 出口温度/℃ 40.42 39.00 3.64 流量/(kg·s−1) 284 284 0 系统参数 系统热功率/MW 15.95 16.75 4.77 系统输出功率/MW 5.31 5.46 2.82 系统热效率 0.34 0.33 2.79 -
[1] FERRERO S, BATET L, LINARES J I, et al. A modelica dynamic model of a supercritical CO2 energy conversion system for EU-DEMO[J]. Fusion Engineering and Design, 2021, 173: 112826. doi: 10.1016/j.fusengdes.2021.112826 [2] DELGOSHAEI P, HEIDARINEJAD M, AUSTIN M A. Semantic inference-based control strategies for building HVAC systems using modelica-based physical models[J]. Procedia Engineering, 2017, 205: 1975-1982. doi: 10.1016/j.proeng.2017.10.060 [3] 刘伟,丁建完,赵建军,等. 基于Modelica的载人航天器环热控系统建模仿真[J]. 航天器环境工程,2017, 34(2): 143-149. [4] 李冰洁,张晓斌,吴小华,等. 基于Dymola及Modelica语言的飞机三级发电机的建模与仿真[J]. 微电机,2016, 49(3): 40-44. [5] 杨世铭,陶文铨. 传热学[M]. 第四版. 北京: 高等教育出版社,1982: 246. [6] 陈卓如,金朝铭. 工程流体力学[M]. 第二版. 北京: 高等教育出版社,1992: 265. [7] GAO C T, WU P, SHAN J Q, et al. Preliminary study of system design and safety analysis methodology for supercritical carbon dioxide Brayton cycle direct-cooled reactor system[J]. Annals of Nuclear Energy, 2020, 147: 107734. doi: 10.1016/j.anucene.2020.107734 [8] CARSTENS N A, HEJZLAR P, DRISCOLL M J. Control system strategies and dynamic response for supercritical CO2 power conversion cycles: MIT-GFR-038[R]. Cambrige: MIT Nuclear Engineering Department, 2006. [9] CARSTENS N A. Control strategies for supercritical carbon dioxide power conversion systems[D]. Cambridge: Massachusetts Institute of Technology, 2007.