Experiment on expander inlet superheat of organic Rankine cycle

doi:10.16085/j.issn.1000-6613.2016.07.011

Abstract

Abstract: This article discusses the effect of expander inlet superheat on the performance of expander and the organic Rankine cycle (ORC) system at fixed heat source. An ORC experimental rig was constructed with scroll expander, and dichlorotrifluoroethane (R123) was selected as the working fluid. At 140℃, experiments were carried out by adjusting the expander torque to control the system evaporation pressure, to regulate the expander inlet superheat. Experimental results showed that the maximum shaft power and actual operating efficiency of the expander were 2.35 kW and 59.7 %, respectively. The maximum net output power, thermal efficiency and exergy efficiency of the ORC system were 1.75 kW, 5.3 % and 21.8 %, respectively. Analysis showed that with the expander inlet superheat decreased, the expander mechanical efficiency increased while the expander isentropic efficiency decreased. As the superheat decreased, the shaft power and actual operating efficiency of the expander first increased, then decreased. When the expander inlet superheat was about 20℃, the expander showed the maximum output power, and the ORC system provided the highest net output power, thermal efficiency and exergy efficiency, simultaneously. Besides, expander inlet superheat influenced the exergy destruction distribution of the ORC system. With the expander inlet superheat decreased, the expander exergy destruction first increased and then decreased.

Key words: organic Rankine cycle, superheat, thermal efficiency, exergy efficiency, exergy destruction

摘要： 在给定热源条件下,探讨有机朗肯循环(ORC)膨胀机入口过热度对膨胀机性能和ORC系统性能的影响。建立了带前置泵的ORC实验系统,采用涡旋式膨胀机,R123为工质,在140℃热源下进行实验。通过改变膨胀机转矩调节系统蒸发压力,从而实现对膨胀机入口过热度的调节。实验获得最大膨胀机轴功和膨胀机实际运行效率分别为2.35kW和59.7%;ORC系统净输出功、热效率和(火用)效率分别为1.75kW、5.3%和21.8%。分析表明,随着膨胀机入口过热度递减,膨胀机机械效率递增,膨胀机等熵效率递减,膨胀机轴功和实际运行效率呈先增后减的变化趋势。膨胀机入口过热度为20℃左右时,有最大膨胀机轴功、最大系统净输出功、最高系统热效率和最高系统(火用)效率。此外,过热度影响系统的损失分布,随着膨胀机入口过热度减小,膨胀机(火用)损呈先增后减变化。

关键词: 有机朗肯循环, 过热度, 热效率, (火用)效率, (火用)损

CLC Number:

TK114

YANG Xufei, QI Fengliang, LIU Xiulong, ZOU Jinghuang, XU Jinliang . Experiment on expander inlet superheat of organic Rankine cycle[J]. Chemical Industry and Engineering Progree, 2016, 35(07): 2007-2014.

杨绪飞, 戚风亮, 刘秀龙, 邹景煌, 徐进良. 有机朗肯循环膨胀机入口过热度实验[J]. 化工进展, 2016, 35(07): 2007-2014.

References

[1] LIU Q,DUAN Y Y,YANG Z.Performance analyses of geothermal organic Rankine cycles with selected hydrocarbon working fluids[J].Energy,2013,63:123-132.
[2] GHASEMI H,PACI M,TIZZANINI A,et al.Modeling and optimization of a binary geothermal power plant[J].Energy, 2013,50:412-428.
[3] 李晶,裴刚,季杰.太阳能有机朗肯循环低温热发电关键因素分析[J].化工学报,2009,60(4):826-832.
[4] WANG X D,ZHAO L,WANG J L,et al.Performance evaluation of a low-temperature solar Rankine cycle system utilizing R245fa [J].Solar Energy,2010,84(3):353-364.
[5] AL-SULAIMAN F A.Exergy analysis of parabolic trough solar collectors integrated with combined steam and organic Rankine cycles[J].Energy Conversion and Management,2014,77:441-449.
[6] 李虎,张于峰,李鑫钢,等.低温发电系统在精馏工艺中的节能技术[J].化工进展,2013,32(5):1187-1193.
[7] 刘超,徐进良.一种新型天然气锅炉烟气预热器回收系统[J].化工学报,2013,64(11):4223-4230.
[8] 张墨耕,赵良举,刘朝,等.利用LNG冷能与工业余热的有机朗肯循环负荷系统优化分析[J].化工学报,2014,65(8):3144- 3151.
[9] 刘杰,陈江平,祁照岗.低温有机朗肯循环的热力学分析[J].化工学报,2010,61(s2):9-14.
[10] 张红光,张健,杨凯,等.柴油机全工况下抽气回热式有机朗肯循环系统分析[J].农业机械学报,2014, 45(8):19-26.
[11] 韩中合,杜燕,王智.有机朗肯循环低温余热回收系统的工质选择[J].化工进展,2014,33(9):2279-2285.
[12] SALEH B,KOGLBAUER G,WENDLAND M,et al.Working fluids for low-temperature organic Rankine cycles[J]. Energy,2007,32:1210-1221.
[13] 吴双应,易甜甜,肖兰.基于多目标函数的亚临界有机朗肯循环的参数优化和性能分析[J] .化工学报,2014,65(10):4078- 4085.
[14] BELL I H,LEMORT V,GROLL E A,et al.Liquid flooded compression and expansion in scroll machines - Part II: Experimental testing and model validation[J].International Journal of Refrigeration,2012,35:1890-1900.
[15] BRACCO R,CLEMENTE S,MICHELI D,et al.Experimental tests and modelization of a domestic-scale ORC(organic Rankine cycle)[J].Energy,2013,58:107-116.
[16] LEE Y R,KUN C R,LIU C H,et al.Dynamic response of a 50 kW organic Rankine cycle system in association with evaporators[J].Energies,2014,7:2436-2448.
[17] CHANG J C,HUNG T C,HE Y L,et al.Experimental study on low-temperature organic Rankine cycle utilizing scroll type expander[J].Applied Energy,2015,155:150-159.
[18] YANG X F,XU J L,MIAO Z,et al.Operation of an organic Rankine cycle dependent on pumping flow rates and expander torques[J].Energy,2015,90:864-878.
[19] MAGO P J,SRINIVASAN K K,CHAMRA L M,et al.An examination of exergy destruction in organic Rankine cycles[J].International Journal of Energy Research,2008,32:926-938.
[20] TCHANCHE B F,LAMBRINOS G,FRANGOUDAKIS A,et al.Exergy analysis of micro-organic Rankine power cycles for a small scale solar driven reverse osmosis desalination system[J].Applied Energy,2010,87:1295-1306.
[21] MIAO Z,YANG X F,XU J L,et al.Development and dynamic characteristics of an organic Rankine cycle[J].Chinese Science Bulletin,2014,59(33):4367-4378.
[22] 杨绪飞,邹景煌,戚风亮,等.用于有机朗肯循环的三柱塞泵运行性能实验[J].农业机械学报,2015,46(8):367-371, 378.
[23] 杨绪飞,徐进良,戚风亮,等.带有前置泵的有机朗肯循环实验[J].农业机械学报,2015,50(12):385-390,396.
[24] MIAO Z,XU J L,YANG X F,et al.Operation and performance of a low temperature organic Rankine cycle[J].Applied Thermal Engineering,2015,75(22):1065-1075.
[25] BAEHR H D,STEPHAN K.Heat and mass transfer[M].2nd ed.Burlin:Springer,2006:477-479.