Coupling effect of evaporation and condensation processes of organic Rankine cycle for geothermal power generation improvement


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Organic Rankine cycle (ORC) is widely used for the low grade geothermal power generation. However, a large amount of irreversible loss results in poor technical and economic performance due to its poor matching between the heat source/sink and the working medium in the condenser and the evaporator. The condensing temperature, cooling water temperature difference and pinch point temperature difference are often fixed according to engineering experience. In order to optimize the ORC system comprehensively, the coupling effect of evaporation and condensation process was proposed in this paper. Based on the laws of thermodynamics, the energy analysis, exergy analysis and entropy analysis were adopted to investigate the ORC performance including net output power, thermal efficiency, exergy efficiency, thermal conductivity, irreversible loss, etc., using geothermal water at a temperature of 120 °C as the heat source and isobutane as the working fluid. The results show that there exists a pair of optimal evaporating temperature and condensing temperatures to maximize the system performance. The net power output and the system comprehensive performance achieve their highest values at the same evaporating temperature, but the system comprehensive performance corresponds to a lower condensing temperature than the net power output.


有机朗肯循环(ORC)被广泛应用于低品位地热发电中, 但是由于冷凝器和蒸发器中的热源/散热 器与工质的匹配性差导致了大量的不可逆损失, 严重影响了系统的技术经济性能. 并且冷凝温度, 冷 却水温差, 窄点温差通常根据工程经验被设为固定值. 为了将ORC 系统进行全面系统的优化, 本文 提出了蒸发冷凝过程的耦合效应, 基于热力学定律, 采用能量分析, 火用分析和熵分析对温度为120 °C 的地热水作为热源, 异丁烷作为工作流体的ORC 性能各项参数进行优化研究. 结果表明, 存在一组 最佳蒸发温度和冷凝温度使系统性能得到最大限度地提高; 净功率输出和系统综合性能在相同蒸发温 度下达到最佳值, 但系统达到最佳综合性能时对应的冷凝温度要低于达到最佳净输出功率时所对应的 冷凝温度.

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  1. [1]

    GONZALEZ J E, MONCEF K. Handbook of integrated and sustainable buildings equipment and systems, volume I: Energy systems [M]. American Society of Mechanical Engineers, 2017.

  2. [2]

    LI Gang, HWANG Y, RADERMACHER R. Cold thermal energy storage materials and applications toward sustainability [M]// Energy Solutions to Combat Global Warming. Springer, Cham, 2017.

  3. [3]

    LI Gang, ZHENG Xue-fei. Thermal energy storage system integration forms for a sustainable future [J]. Renewable and Sustainable Energy Reviews, 2016, 62: 736–757.

  4. [4]

    LIU Ke-tao, ZHU Jia-ling, HU Kai-yong, WU Xiu-jie. Analysis on optimal working fluid flow rate and unstable power generation for miniaturized ORC systems [J]. Journal of Central South University, 2016, 23(5): 1224–1231.

  5. [5]

    LIU, Chang-wei, GAO Tie-yu. Off-design performance analysis of basic ORC, ORC using zeotropic mixtures and composition-adjustable ORC under optimal control strategy [J]. Energy, 2019, 171: 95–108.

  6. [6]

    KONG R, DEETHAYAT T, ASANAKHAM A, VORAYOS N, KIATSIRIROAT T. Thermodynamic performance analysis of a R245fa organic Rankine cycle (ORC) with different kinds of heat sources at evaporator [J]. Case Studies in Thermal Engineering, 2019, 13: 100385.

  7. [7]

    PILI R, ROMAGNOLI A, SPLIETHOFF H, WIELAND C. Techno-economic analysis of waste heat recovery with ORC from fluctuating industrial sources [J]. Energy Procedia, 2017, 129: 503–510.

  8. [8]

    CAVAZZINI G, dal TOSO P. Techno-economic feasibility study of the integration of a commercial small-scale ORC in a real case study [J]. Energy Conversion and Management, 2015, 99: 161–175.

  9. [9]

    LI Gang. Organic Rankine cycle performance evaluation and thermoeconomic assessment with various applications part I: Energy and exergy performance evaluation [J]. Renewable and Sustainable Energy Reviews, 2016, 53: 477–499.

  10. [10]

    LI Gang. Organic Rankine cycle performance evaluation and thermoeconomic assessment with various applications part II: economic assessment aspect [J]. Renewable and Sustainable Energy Reviews, 2016, 64: 490–505.

  11. [11]

    SUN Fa-ming, IKEGAMI Y, JIA B, ARIMA H. Optimization design and exergy analysis of organic Rankine cycle in ocean thermal energy conversion [J]. Applied Ocean Research, 2012, 35: 38–46.

  12. [12]

    USTAOGLU A, ALPTEKIN M, AKAY M E. Thermal and exergetic approach to wet type rotary kiln process and evaluation of waste heat powered ORC (Organic Rankine cycle) [J]. Applied Thermal Engineering, 2017, 112: 281–295.

  13. [13]

    NI Jia-xin, ZHAO Li, ZHANG Zheng-tao, ZHANG Ying, ZHANG Jian-yuan, DENG Shuai, MA Ming-lu. Dynamic performance investigation of organic Rankine cycle driven by solar energy under cloudy condition [J]. Energy, 2018, 147: 122–141.

  14. [14]

    TAFONE A, BORRI E, COMODI G, van den BROEK M, ROMAGNOLI A. Preliminary assessment of waste heat recovery solution (ORC) to enhance the performance of liquid air energy storage system [J]. Energy Procedia, 2017, 142: 3609–3616.

  15. [15]

    BINA S M, JALILINASRABADY S, FUJII H. Energy, economic and environmental (3E) aspects of internal heat exchanger for ORC geothermal power plants [J]. Energy, 2017, 140: 1096–1106.

  16. [16]

    van ERDEWEGHE S, van BAEL J, LAENEN B, D’HAESELEER W. Feasibility study of a low-temperature geothermal power plant for multiple economic scenarios [J]. Energy, 2018, 155: 1004–1012.

  17. [17]

    BIANCHI M, BRANCHINI L, de PASCALE A, MELINO F, OTTAVIANO S, PERETTO A, TORRICELLI N, ZAMPIERI G. Performance and operation of micro-ORC energy system using geothermal heat source [J]. Energy Procedia, 2018, 148: 384–391.

  18. [18]

    MAGO P J, SRINIVASAN K K, CHAMRA L M, SOMAYAJI C. An examination of exergy destruction in organic Rankine cycles [J]. International Journal of Energy Research, 2008, 32(10): 926–938.

  19. [19]

    MAGO P J, CHAMRA L M, SRINIVASAN K, SOMAYAJI C. An examination of regenerative organic Rankine cycles using dry fluids [J]. Applied Thermal Engineering, 2008, 28(8, 9): 998–1007.

  20. [20]

    TCHANCHE B F, LAMBRINOS G, FRANGOUDAKIS A, PAPADAKIS G. Exergy analysis of micro-organic Rankine power cycles for a small scale solar driven reverse osmosis desalination system [J]. Applied Energy, 2010, 87(4): 1295–1306.

  21. [21]

    LI Tai-lu, ZHANG Zhi-gang, LU Jian, YANG Jun-lan, HU Yu-jie. Two-stage evaporation strategy to improve system performance for organic Rankine cycle [J]. Applied Energy, 2015, 150: 323–334.

  22. [22]

    LI Tai-lu, YUAN Zhen-he, LI Wei, YANG Jun-lan, ZHU Jia-ling. Strengthening mechanisms of two-stage evaporation strategy on system performance for organic Rankine cycle [J]. Energy, 2016, 101: 532–540.

  23. [23]

    WANG Zhi-qi, ZHOU Qi-yu, XIA Xiao-xia, LIU Bin, ZHANG Xin. Performance comparison and analysis of a combined power and cooling system based on organic Rankine cycle [J]. Journal of Central South University, 2017, 24(2): 353–359.

  24. [24]

    THIERRY D M, FLORES-TLACUAHUAC A, GROSSMANN I E. Simultaneous optimal design of multistage organic Rankine cycles and working fluid mixtures for low-temperature heat sources [J]. Computers & Chemical Engineering, 2016, 89: 106–126.

  25. [25]

    SALEH B, KOGLBAUER G, WENDLAND M, FISCHER J. Working fluids for low-temperature organic Rankine cycles [J]. Energy, 2007, 32(7): 1210–1221.

  26. [26]

    LI Gang. Organic Rankine cycle environmental impact investigation under various working fluids and heat domains concerning refrigerant leakage rates [J]. International Journal of Environmental Science and Technology, 2019, 16(1): 431–450.

  27. [27]

    LI Tai-lu, ZHU Jia-ling, ZHANG Wei. Performance analysis and improvement of geothermal binary cycle power plant in oilfield [J]. Journal of Central South University, 2013, 20(2): 457–465.

  28. [28]

    ALJUNDI I H. Effect of dry hydrocarbons and critical point temperature on the efficiencies of organic Rankine cycle [J]. Renewable Energy, 2011, 36(4): 1196–1202.

  29. [29]

    YARI M. Performance analysis of the different organic Rankine cycles (ORCs) using dry fluids [J]. International Journal of Exergy, 2009, 6(3): 323–342.

  30. [30]

    XU Peng, LU Jian, LI Tai-lu, ZHU Jia-ling. Thermodynamic optimization and fluid selection of organic Rankine cycle driven by a latent heat source [J]. Journal of Central South University, 2017, 24(12): 2829–2841.

  31. [31]

    LIU Qiang, SHEN Ai-jing, DUAN Yuan-yuan. Parametric optimization and performance analyses of geothermal organic Rankine cycles using R600a/R601a mixtures as working fluids [J]. Applied Energy, 2015, 148: 410–420.

  32. [32]

    LIU Qiang, DUAN Yuan-yuan, YANG Zhen. Effect of condensation temperature glide on the performance of organic Rankine cycles with zeotropic mixture working fluids [J]. Applied Energy, 2014, 115: 394–404.

  33. [33]

    HU Kai-yong, ZHU Jia-ling, LI Tai-lu, ZHANG Wei. Experimental investigation on characteristics of evaporator vaporization and pressure drops in an Organic Rankine Cycle (ORC) [J]. Energy Procedia, 2015, 75: 1631–1638.

  34. [34]

    SUN Jie, LIU Qiang, DUAN Yuan-yuan. Effects of evaporator pinch point temperature difference on thermoeconomic performance of geothermal organic Rankine cycle systems [J]. Geothermics, 2018, 75: 249–258.

  35. [35]

    OZDIL N F T, SEGMEN M R, TANTEKIN A. Thermodynamic analysis of an Organic Rankine Cycle (ORC) based on industrial data [J]. Applied Thermal Engineering, 2015, 91: 43–52.

  36. [36]

    ZHAO Meng, WEI Ming-shan, SONG Pan-pan, LIU Zhen, WANG Zhi-xiang. Effects of the ORC operating conditions on the engine performance for an Engine-ORC combined system [J]. Energy Procedia, 2017, 105: 662–667.

  37. [37]

    XU Rong-ji, HE Ya-Ling. A vapor injector-based novel regenerative organic Rankine cycle [J]. Applied Thermal Engineering, 2011, 31(6, 7): 1238–1243.

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Author information

Correspondence to Tai-lu Li 李太禄.

Additional information

Foundation item: Project(2018YFB1501805) supported by the National Key Research and Development Program of China; Project(51406130) supported by the National Natural Science Foundation of China; Project(201604-504) supported by the Key Laboratory of Efficient Utilization of Low and Medium Grade Energy (Tianjin University), China

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Yang, H., Meng, N. & Li, T. Coupling effect of evaporation and condensation processes of organic Rankine cycle for geothermal power generation improvement. J. Cent. South Univ. 26, 3372–3387 (2019) doi:10.1007/s11771-019-4260-y

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Key words

  • Organic Rankine cycle
  • geothermal power generation
  • coupling effect of evaporation and condensation
  • exergy analysis


  • 有机朗肯循环
  • 地热发电
  • 蒸发冷凝耦合效应
  • 火用分析