闭式热源下混合工质与纯工质的ORC性能比较

doi:10.11949/0438-1157.20190882

摘要/Abstract

摘要：

为了全面比较有机朗肯循环(ORC)中混合工质与纯工质的性能优劣，在给定供热量及进出口温度的闭式热源条件下，建立了基本ORC和回热ORC的数值仿真模型，所用工质为R600a/R601a，所用冷源为一定流量范围的冷却水。在模拟中，以最大净输出功为目标，同步优化循环的蒸发及冷凝温度，得到了不同组分工质的性能参数。比较结果表明，混合工质的热力性能不一定优于纯工质。在闭式热源下，相变换热器中具有更好温度匹配的混合工质一般也具有更小的换热损失。针对回热ORC，回热器将影响工质在相变换热器中的温度分布，但对相变换热器中的损失影响较小。

关键词: 混合工质, 有机朗肯循环, 回热器, 闭式热源, 热力性能比较

Abstract:

In order to compare the performance of zeotropic mixtures and pure fluids in organic Rankine cycle (ORC), a numerical simulation model is established for basic ORC and ORC with internal heat exchanger (IHE) under the closed heat source with given heat supply and inlet and outlet temperatures. Mixtures R600a/R601a at different mass fractions are employed, and a certain range of mass flow rate of cooling water is considered as the condition of heat sink. In the simulation, the cycle evaporation and condensation temperatures are simultaneously optimized to obtain the maximum net output power, and the performance parameters of mixtures and pure fluids are obtained. Based on the performance comparison, it can be concluded that zeotropic mixtures are not certain to have higher cycle performance than pure fluids. Under the given condition of closed heat source, mixtures generally have better temperature matches in the evaporator and condenser, so that exergy losses of these heat exchangers are reduced. Regarding the ORC with IHE, IHE will affect the temperature distribution of the working medium in the phase change heat exchanger, but it has a small effect on the plutonium loss in the phase change heat exchanger.

Key words: zeotropic mixture, organic Rankine cycle, internal heat exchanger, closed heat source, thermodynamic performance comparison

中图分类号:

TK 123

明勇, 彭艳楠, 苏文, 魏国龙, 王强, 周乃君, 赵力. 闭式热源下混合工质与纯工质的ORC性能比较[J]. 化工学报, 2020, 71(4): 1570-1579.

Yong MING, Yannan PENG, Wen SU, Guolong WEI, Qiang WANG, Naijun ZHOU, Li ZHAO. Thermodynamic performance comparison of ORC between mixtures and pure fluids under closed heat source[J]. CIESC Journal, 2020, 71(4): 1570-1579.

图/表 13

图1 混合工质ORC循环T-s图

Fig.1 T-s diagram of ORC with zeotropic mixture

图2 不同泡点温度下R600a/R601a的温度滑移

Fig.2 Temperature glides of R600a/R601a at different bubble temperatures

表1 闭式热源下的循环工况

Table 1 Cycle conditions for closed heat source

系统稳定参数	值
加压水进口温度/K	413.15
加压水出口温度/K	353.15
供热量/kW	300, 350, 400
蒸发过热度范围/K	0~15
冷凝过冷度/K	0
系统压力范围/MPa	0.1~2.5
冷却水进口温度/K	293.15
冷却水流量范围/(kg/s)	4~12
蒸发器窄点温差/K	15
冷凝器窄点温差/K	10
回热器窄点温差/K	10
工质泵等熵效率 $η p u m p$ /%	60
膨胀机等熵效率 $η e x p$ /%	75

表1 闭式热源下的循环工况

Table 1 Cycle conditions for closed heat source

系统稳定参数	值
加压水进口温度/K	413.15
加压水出口温度/K	353.15
供热量/kW	300, 350, 400
蒸发过热度范围/K	0~15
冷凝过冷度/K	0
系统压力范围/MPa	0.1~2.5
冷却水进口温度/K	293.15
冷却水流量范围/(kg/s)	4~12
蒸发器窄点温差/K	15
冷凝器窄点温差/K	10
回热器窄点温差/K	10
工质泵等熵效率 $η p u m p$ /%	60
膨胀机等熵效率 $η e x p$ /%	75

图3 工质流量随R600a质量分数的变化

Fig.3 Mass flow rate of working fluids at different mass fractions

图4 冷却水流量随R600a质量分数的变化

Fig.4 Mass flow rate of cooling water at different mass fractions

图5 回热器热量随R600a质量分数的变化

Fig.5 Regenerative heat in IHE at different mass fractions

图6 输出功随R600a质量分数的变化

Fig.6 Output work at different mass fractions

图7 循环效率随R600a质量分数的变化

Fig.7 Cycle efficiency at different mass fractions

图8 蒸发器内流体温度及温差分布

Fig.8 Temperature distribution and temperature difference in evaporator

图9 冷凝器内流体温度及温差分布

Fig.9 Temperature distribution and temperature difference in condenser

图10 回热器中工质温度及温差分布

Fig.10 Temperature distribution and temperature difference in IHE

图11 循环系统各部件损失随R600a质量分数的变化

Fig.11 Exergy loss of ORC system at different mass fractions

图12 效率随R600a质量分数的变化

Fig.12 Exergy efficiency at different mass fractions

参考文献 32

1	Su W, Zhao L, Deng S. Developing a performance evaluation model of Organic Rankine Cycle for working fluids based on the group contribution method[J]. Energy Conversion and Management, 2017, 132: 307-315.
2	吴玉庭, 赵英昆, 雷标, 等. 冷却水流量对ORC系统性能影响的实验研究[J]. 化工学报, 2018, 69(6): 2639-2645.
	Wu Y T, Zhao Y K, Lei B, et al. Effect of cooling water flow rate on power generation of organic Rankine cycle system[J]. CIESC Journal, 2018, 69(6): 2639-2645.
3	张红光, 杨宇鑫, 孟凡骁, 等. 有机朗肯循环系统中工质泵的运行性能[J]. 化工学报2017, 68(9): 3573-3579.
	Zhang H G, Yang Y X, Meng F X, et al. Running performance of working fluid pump for organic Rankine cycle system[J]. CIESC Journal, 2017, 68(9): 3573-3579.
4	Lecompte S, Gusev S, Vanslambrouck B, et al. Experimental results of a small-scale organic Rankine cycle: steady state identification and application to off-design model validation[J]. Applied Energy, 2018, 226: 82-106.
5	Saleh B, Gerald K, Martin W, et al. Working fluids for low-temperature organic Rankine cycles[J]. Energy, 2007, 32(7): 1210-1221.
6	Yang L X, Gong M Q, Guo H, et al. Effects of critical and boiling temperatures on system performance and fluid selection indicator for low temperature organic Rankine cycles[J]. Energy, 2016, 109: 830-844.
7	Su W, Zhao L, Deng S. Simultaneous working fluids design and cycle optimization for organic Rankine cycle using group contribution model[J]. Applied Energy, 2017, 202: 618-627.
8	Vivian J, Giovanni M, Andrea L. A general framework to select working fluid and configuration of ORCs for low-to-medium temperature heat sources[J]. Applied Energy, 2015, 156: 727-746.
9	王羽平, 丁小益, 翁一武. 用于ORC发电系统的混合工质R601a/R600a的实验研究[J]. 中国电机工程学报, 2016, 36(12): 3184-3191.
	Wang Y P, Ding X Y, Weng Y W. Experimental study of mixture R601a/R600a used in ORC power generation system[J]. Proceedings of the CSEE, 2016, 36(12): 3184-3191.
10	倪渊. 二元非共沸混合工质低温余热发电ORC系统优化研究[D]. 重庆: 重庆大学, 2013.
	Ni Y. Recovery of low-temperature waste heat by optimization of Organic Rankine Cycle system with binary non-azeotropic mixtures[D]. Chongqing: Chongqing University, 2013.
11	Györke G, Deiters U K, Groniewsky A, et al. Novel classification of pure working fluids for Organic Rankine Cycle[J]. Energy, 2018, 145: 288-300.
12	Landelle A, Tauveron N, Haberschill P, et al. Organic Rankine cycle design and performance comparison based on experimental database[J]. Applied Energy, 2017, 204: 1172-1187.
13	麻建超, 刘玉兰, 陈九法. 混合工质与纯工质在有机朗肯循环系统中输出功及效率的分析对比[J]. 发电设备, 2017, 3: 145-149.
	Ma J C, Liu Y L, Chen J F. Comparative analysis on power output and exergy efficiency of mixed and pure refrigerant in an ORC system [J]. Power Equipment, 2017, 3: 145-149.
14	莫依璃. 工业余热发电二元非共沸混合工质ORC系统研究[D]. 重庆: 重庆大学, 2014.
	Mo Y L. Study on industrial waste heat generation by Organic Rankine Cycle using binary non-azeotropic mixtures[D]. Chongqing: Chongqing University, 2014.
15	Liu Q, Shen A J, Duan Y Y. Parametric optimization and performance analyses of geothermal organic Rankine cycles using R600a/R601a mixtures as working fluids[J]. Applied Energy, 2015, 148: 410-420.
16	Wang X D, Zhao L. Analysis of zeotropic mixtures used in low-temperature solar Rankine cycles for power generation[J]. Solar Energy, 2009, 83(5): 605-613.
17	Li W, Feng X, Yu L J, et al. Effects of evaporating temperature and internal heat exchanger on organic Rankine cycle[J]. Applied Thermal Engineering, 2011, 31(17): 4014-4023.
18	Li Y R, Du M T, Wu C M, et al. Potential of organic Rankine cycle using zeotropic mixtures as working fluids for waste heat recovery[J]. Energy, 2014, 77: 509-519.
19	Su W, Hwang Y, Deng S, et al. Thermodynamic performance comparison of Organic Rankine Cycle between zeotropic mixtures and pure fluids under open heat source[J]. Energy Conversion and Management, 2018, 165: 720-737.
20	Aboelwafa O, Fateen S K, Soliman A, et al. A review on solar Rankine cycles: working fluids, applications, and cycle modifications[J]. Renewable and Sustainable Energy Reviews, 2018, 82: 868-885.
21	Xu W, Deng S, Su W, et al. How to approach Carnot cycle via zeotropic working fluid: research methodology and case study[J]. Energy, 2018, 144: 576-586.
22	Bao J, Zhao L, Zhang W. A novel auto-cascade low-temperature solar Rankine cycle system for power generation[J]. Solar Energy, 2011, 85(11): 2710-2719.
23	柴俊霖, 田瑞, 杨富斌, 等. 车用柴油机余热回收有机朗肯循环系统方案热经济性对比分析[J]. 化工学报, 2017, 68(8): 3258-3265.
	Chai J L, Tian R, Yang F B, et al. Thermo-economic comparative analysis of different organic Rankine cycle system schemes for vehicle diesel engine waste heat recovery[J]. CIESC Journal, 2017, 68(8): 3258-3265.
24	黄仁龙, 罗向龙, 梁志辉, 等. 基于分液冷凝的R245fa/pentane混合工质朗肯循环多目标优化[J]. 化工学报, 2018, 69(5):2040-2048.
	Huang R L, Luo X L, Liang Z H, et al. Multi-objective optimization of Rankine cycle using R245fa/pentane based on liquid-vapor separation [J]. CIESC Journal, 2018, 69(5) :2040-2048.
25	Zhang J Y, Zhao L, Wen J, et al. An overview of 200 kW solar power plant based on organic Rankine cycle[J]. Energy Procedia, 2016, 88: 356-362.
26	Noriega S, Gosselin L, Alexandre K. Designed binary mixtures for subcritical organic Rankine cycles based on multiobjective optimization[J]. Energy Conversion Management, 2018, 156: 585-596.
27	Wang D, Ma Y, Tian R, et al. Thermodynamic evaluation of an ORC system with a low pressure saturated steam heat source[J]. Energy, 2018, 149: 375-385.
28	Park B S, Usman M, Imran M, et al. Review of Organic Rankine Cycle experimental data trends[J]. Energy Conversion Management, 2018, 173: 679-691.
29	Lemmon E W, Huber M L, McLinden M O. NIST Standard Reference Database 23: Reference Fluid Thermodynamic and Transport Properties-REFPROP. 9.0 [R]. USA: National Institute of Standards and Technology (NIST), 2010.
30	Kunz O, Wagner W. The GERG-2008 wide-range equation of state for natural gases and other mixtures: an expansion of GERG-2004[J]. Journal of Chemical and Engineering Data, 2012, 57(11): 3032-3091.
31	Brown J, Brignoli R, Daubman S. Methodology for estimating thermodynamic parameters and performance of working fluids for organic Rankine cycles[J]. Energy, 2014, 73: 818-828.
32	Chys M, van den Broek M, Vanslambrouck B, et al. Potential of zeotropic mixtures as working fluids in organic Rankine cycles [J]. Energy, 2012, 44: 623-632.

[1]	谈莹莹, 刘晓庆, 王林, 黄鲤生, 李修真, 王占伟. R1150/R600a自复叠制冷循环开机动态特性实验研究[J]. 化工学报, 2023, 74(S1): 213-222.
[2]	张曼铮, 肖猛, 闫沛伟, 苗政, 徐进良, 纪献兵. 危废焚烧处理耦合有机朗肯循环系统工质筛选与热力学优化[J]. 化工学报, 2023, 74(8): 3502-3512.
[3]	党玉荣, 莫春兰, 史科锐, 方颖聪, 张子杨, 李作顺. 综合评价模型联合遗传算法的混合工质ORC系统性能研究[J]. 化工学报, 2023, 74(5): 1884-1895.
[4]	吴子睿, 孙瑞, 石凌峰, 田华, 王轩, 舒歌群. CO₂混合工质的气液相平衡的混合规则对比与预测研究[J]. 化工学报, 2022, 73(4): 1483-1492.
[5]	孙铭泽, 马宁, 李浩然, 姜海峰, 洪文鹏, 牛晓娟. 中低温超临界CO₂及其混合工质布雷顿循环热力学分析[J]. 化工学报, 2022, 73(3): 1379-1388.
[6]	海鹏, 李振兴, 李珂, 黄红梅, 郑文帅, 高新强, 戴巍, 沈俊. 多层主动磁回热器的仿真优化[J]. 化工学报, 2021, 72(S1): 302-309.
[7]	罗介霖, 杨凯寅, 赵朕, 王勤, 陈光明. 低GWP混合工质回热热泵采暖性能[J]. 化工学报, 2021, 72(S1): 84-90.
[8]	李子航, 王占博, 苗政, 纪献兵. 亚临界有机朗肯循环系统工质筛选及热经济性分析[J]. 化工学报, 2021, 72(9): 4487-4495.
[9]	曹健, 冯新, 吉晓燕, 陆小华. 基于混合工质的多级蒸发ORC理论极限性能研究[J]. 化工学报, 2021, 72(7): 3780-3787.
[10]	荣杨一鸣, 吴巧仙, 周霞, 方松, 王凯, 邱利民, 植晓琴. 空分系统空气压缩余热自利用性能优化研究[J]. 化工学报, 2021, 72(3): 1654-1666.
[11]	陈超男, 罗向龙, 杨智, 黄仁龙, 卢沛, 陈健勇, 陈颖. 非共沸混合工质组分调控ORC系统热经济性分析和优化[J]. 化工学报, 2020, 71(5): 2373-2381.
[12]	王羽鹏, 梁俊伟, 罗向龙, 李逸帆, 陈健勇, 陈颖. 基于神经网络的有机朗肯循环过程及循环性能计算方法[J]. 化工学报, 2019, 70(9): 3256-3266.
[13]	侯中兰, 魏新利, 马新灵, 孟祥睿. 循环水流量对ORC余热发电系统性能影响的试验分析[J]. 化工学报, 2019, 70(9): 3283-3290.
[14]	陈玉婷, 徐燕燕, 王磊, 叶爽, 黄伟光. 蒸发器换热过程对ORC系统混合工质选择和运行工况的影响[J]. 化工学报, 2019, 70(5): 1723-1733.
[15]	李鹏, 韩中合, 贾晓强, 梅中恺, 韩旭. 动态透平效率对有机朗肯循环系统性能的影响[J]. 化工学报, 2019, 70(4): 1532-1541.