The definition of non-dimensional integration temperature difference and its effect on organic Rankine cycle

The integration temperature difference ΔTi considers the heat transfer routes, linking the heat transfer process with the thermodynamic behavior of heat exchangers. The first and second non-dimensional integration temperature differences are defined as ΔTi,h∗=ΔTi/Th,i and ΔTi,s∗=ΔTi/(Th,i-T0) respectively, where Th,i is the heat source temperature and T0 is the environment temperature. This paper is the first to experimentally verify the significance of the non-dimensional integration temperature differences on organic Rankine cycle (ORC) systems. The first non-dimensional temperature difference is shown to have linear relationship with the revised entropy generation numbers (Ns). With increases of the second non-dimensional integration temperature difference, the expander powers, system thermal and exergy efficiencies had parabola distributions. They simultaneously reached maximum at ΔTi,s∗=0.282, under which the vapor cavitation in the expander disappears and the exergy losses of heat exchangers are acceptable to elevate the expander efficiency. Beyond the optimal point, the ORC performance is worsened either due to the vapor cavitation in the expander, or due to the poor thermal matches in the evaporator and condenser. The second non-dimensional integration temperature difference comprehensively reflects the effects of heat source temperatures, heating powers and organic fluid flow rates and pressures, etc. It balances exergy destructions of various components to optimize the system. Thus, it can be an important parameter index to maximize the power or electricity output for a specific heat source. The usefulness of the integration temperature difference and the future work are discussed in the end of this paper.

[1]  Fahad A. Al-Sulaiman,et al.  Exergy modeling of a new solar driven trigeneration system , 2011 .

[2]  Tzu-Chen Hung,et al.  Experimental study on low-temperature organic Rankine cycle utilizing scroll type expander , 2015 .

[3]  Muhammad Imran,et al.  Multi-objective optimization of evaporator of organic Rankine cycle (ORC) for low temperature geothermal heat source , 2015 .

[4]  Fahad A. Al-Sulaiman,et al.  Greenhouse gas emission and exergy assessments of an integrated organic Rankine cycle with a biomass combustor for combined cooling, heating and power production , 2011 .

[5]  Karl Stephan,et al.  Convective heat and mass transfer. Flows with phase change , 2006 .

[6]  Yiping Dai,et al.  Exergy analyses and parametric optimizations for different cogeneration power plants in cement industry , 2009 .

[7]  Yasuyuki Ikegami,et al.  Optimization design and exergy analysis of organic rankine cycle in ocean thermal energy conversion , 2012 .

[8]  Larry C. Witte,et al.  A Thermodynamic Efficiency Concept for Heat Exchange Devices , 1983 .

[9]  Jian Zhang,et al.  Study of zeotropic mixtures of ORC (organic Rankine cycle) under engine various operating conditions , 2013 .

[10]  D. Brüggemann,et al.  Exergy based fluid selection for a geothermal Organic Rankine Cycle for combined heat and power generation , 2010 .

[11]  Jun Zhao,et al.  Experimental investigations on solar chimney for optimal heat collection to be utilized in organic Rankine cycle , 2015 .

[12]  Hong Guang Zhang,et al.  Heat transfer analysis of a finned-tube evaporator for engine exhaust heat recovery , 2013 .

[13]  Min-Hsiung Yang,et al.  Analyzing the optimization of an organic Rankine cycle system for recovering waste heat from a large marine engine containing a cooling water system , 2014 .

[14]  S. C. Kaushik,et al.  Second law thermodynamic study of heat exchangers: A review , 2014 .

[15]  Pedro J. Mago,et al.  An examination of exergy destruction in organic Rankine cycles , 2008 .

[16]  Alexander Mitsos,et al.  A double-pinch criterion for regenerative Rankine cycles , 2012 .

[17]  Jihong Wang,et al.  Exergy analysis and optimization of a hydrogen production process by a solar-liquefied natural gas hybrid driven transcritical CO2 power cycle , 2012 .

[18]  You-Rong Li,et al.  Influence of coupled pinch point temperature difference and evaporation temperature on performance of organic Rankine cycle , 2012 .

[19]  I. Dincer,et al.  Exergy and exergoeconomic analyses and optimization of geothermal organic Rankine cycle , 2013 .

[20]  Chao Liu,et al.  Effect of the critical temperature of organic fluids on supercritical pressure Organic Rankine Cycles , 2013 .

[21]  Zhen Yang,et al.  Effect of condensation temperature glide on the performance of organic Rankine cycles with zeotropic mixture working fluids , 2014 .

[22]  Steven Lecompte,et al.  Exergy analysis of zeotropic mixtures as working fluids in organic rankine cycles , 2014 .

[23]  Ibrahim Dincer,et al.  Energy and exergy analyses and optimization study of an integrated solar heliostat field system for hydrogen production , 2012 .

[24]  Donna Post Guillen,et al.  Development of a Direct Evaporator for the Organic Rankine Cycle , 2011 .

[25]  Jinliang Xu,et al.  A new design method for Organic Rankine Cycles with constraint of inlet and outlet heat carrier fluid temperatures coupling with the heat source , 2012 .

[26]  Jinliang Xu,et al.  Transcritical pressure Organic Rankine Cycle (ORC) analysis based on the integrated-average temperature difference in evaporators , 2015 .

[27]  Li Zhao,et al.  Exergy analysis and parameter study on a novel auto-cascade Rankine cycle , 2012 .

[28]  Fahad A. Al-Sulaiman,et al.  Energy and exergy analyses of a biomass trigeneration system using an organic Rankine cycle , 2012 .

[29]  A. S. Nafey,et al.  Combined solar organic Rankine cycle with reverse osmosis desalination process: Energy, exergy, and cost evaluations , 2010 .

[30]  Onder Kaska,et al.  Energy and exergy analysis of an organic Rankine for power generation from waste heat recovery in steel industry , 2014 .

[31]  Vincent Lemort,et al.  Systematic optimization of subcritical and transcritical organic Rankine cycles (ORCs) constrained by technical parameters in multiple applications , 2014 .

[32]  Xiao Feng,et al.  A new pinch based method for simultaneous selection of working fluid and operating conditions in an ORC (Organic Rankine Cycle) recovering waste heat , 2015 .

[33]  Andrea Toffolo,et al.  A multi-criteria approach for the optimal selection of working fluid and design parameters in Organic Rankine Cycle systems , 2014 .

[34]  Vasile Minea,et al.  Power generation with ORC machines using low-grade waste heat or renewable energy , 2014 .

[35]  Jinliang Xu,et al.  Operation of an organic Rankine cycle dependent on pumping flow rates and expander torques , 2015 .

[36]  Naijun Zhou,et al.  Experimental study on Organic Rankine Cycle for waste heat recovery from low-temperature flue gas , 2013 .

[37]  Jian Song,et al.  Performance analysis of a dual-loop organic Rankine cycle (ORC) system with wet steam expansion for engine waste heat recovery , 2015 .

[38]  I. Dincer,et al.  Energy and exergy analyses of hydrogen production via solar-boosted ocean thermal energy conversion and PEM electrolysis , 2013 .

[39]  Chi-Chuan Wang,et al.  Dynamic Response of a 50 kW Organic Rankine Cycle System in Association with Evaporators , 2014 .

[40]  Shien Hui,et al.  Liquid drop impact on solid surface with application to water drop erosion on turbine blades, Part I: Nonlinear wave model and solution of one-dimensional impact , 2008 .

[41]  Pedro J. Mago,et al.  Exergy analysis of a combined engine-organic Rankine cycle configuration , 2008 .

[42]  Ruzhu Wang,et al.  Simulation and experiments on an ORC system with different scroll expanders based on energy and exergy analysis , 2015 .

[43]  N. Lai,et al.  Working fluids for high-temperature organic Rankine cycles , 2007 .

[44]  Giovanna Cavazzini,et al.  Techno-economic feasibility study of the integration of a commercial small-scale ORC in a real case study , 2015 .

[45]  Maogang He,et al.  A combined thermodynamic cycle used for waste heat recovery of internal combustion engine , 2011 .

[46]  Jinliang Xu,et al.  Organic Rankine cycle saves energy and reduces gas emissions for cement production , 2015 .

[47]  Sedat Sisbot,et al.  Exergy analysis of electricity generation for the geothermal resources using organic rankine cycle: Kızıldere‐denizli case , 2013 .

[48]  Jinliang Xu,et al.  Critical temperature criterion for selection of working fluids for subcritical pressure Organic Rankine cycles , 2014 .