Analysis of the thermodynamic performance of the organic Rankine cycle (ORC) based on the characteristic parameters of the working fluid and criterion for working fluid selection

2020 ◽  
Vol 211 ◽  
pp. 112746 ◽  
Author(s):  
Wei Fan ◽  
Zhonghe Han ◽  
Peng Li ◽  
Yalei Jia
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Characteristic Parameters ◽  
Thermodynamic Performance ◽  
Working Fluid Selection

Performance Investigation of Solar Organic Rankine Cycle Systems With and Without Regeneration and With Zeotropic Working Fluid Mixtures for Use in Micro-Cogeneration

2020 ◽  
Author(s):  
Wahiba Yaïci ◽  
Evgueniy Entchev ◽  
Pouyan Talebizadeh Sardari
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
High Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Industrial Wastes ◽  
Working Fluid ◽  
Condensation Temperature ◽  
Thermodynamic Performance ◽  
Cycle Efficiency

Abstract Globally there are several viable sources of renewable, low-temperature heat (below 130°C) particularly solar energy, geothermal energy, and energy generated from industrial wastes. Increased exploitation of these low-temperature options has the definite potential of reducing fossil fuel consumption with its attendant very harmful greenhouse gas emissions. Researchers have universally identified the organic Rankine cycle (ORC) as a practicable and promising system to generate electrical power from renewable sources based on its beneficial use of volatile organic fluids as working fluids (WFs). In recent times, researchers have also shown a preference for/an inclination towards deployment of zeotropic mixtures as ORC WFs because of their capacity to improve thermodynamic performance of ORC systems, a feat enabled by better matches of the temperature profiles of the WF and the heat source/sink. This paper demonstrates both the technical feasibility and the notable advantages of using zeotropic mixtures as WFs through a simulation study of an ORC system. The study examines the thermodynamic performance of ORC systems using zeotropic WF mixtures to generate electricity driven by low-temperature solar heat source for building applications. A thermodynamic model is developed with an ORC system both with and excluding a regenerator. Five zeotropic mixtures with varying compositions of R245fa/propane, R245fa/hexane, R245fa/heptane, pentane/hexane and isopentane/hexane are evaluated and compared to identify the best combinations of WF mixtures that can yield high efficiency in their system cycles. The study also investigates the effects of the volumetric flow ratio, and evaporation and condensation temperature glides on the ORC’s thermodynamic performance. Following a detailed analysis of each mixture, R245fa/propane is selected for parametric study to examine the effects of operating parameters on the system’s efficiency and sustainability index. For zeotropic mixtures, results showed that there is an optimal composition range within which binary mixtures are inclined to perform more efficiently than the component pure fluids. In addition, a significant increase in cycle efficiency can be achieved with a regenerative ORC, with cycle efficiency ranging between 3.1–9.8% and 8.6–17.4% for ORC both without and with regeneration, respectively. Results also showed that exploiting zeotropic mixtures could enlarge the limitation experienced in selecting WFs for low-temperature solar organic Rankine cycles.

Optimization of Overcritical Organic Rankine Cycle

2016 ◽  
Vol 831 ◽  
pp. 306-315
Author(s):  
Qing Quan Wang ◽  
Sławomir Smoleń
Keyword(s):  
Numerical Method ◽  
Thermal Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Independent Variables ◽  
Hot Temperature ◽  
Working Fluid Selection ◽  
Two Independent Variables

This paper explores the optimization cases for overcritical Organic Rankine Cycle (ORC) in various situations. First the ORC optimization in terms of working fluid selection is discussed. In this case, thermal efficiencies for 10 different working fluids have been calculated under certain temperature frames and the results are compared. Second, overcritical optimization case in terms of variation of hot temperature and evaporation pressure is presented. In this overcritical ORC case, the influence of evaporation pressure on ORC thermal efficiency is studied by conducting a case study of R234a, and first 1-D freedom optimization case is discussed within the variation of evaporation pressure. 2-D freedom optimization is also considered, in which the two independent variables, hot temperature and evaporation pressure, are both varied within certain boundaries. This study employs numerical method for this 2-D problem and it is also presented in detail in the case study.

scholarly journals Organic Rankine Cycle system performance targeting and design for multiple heat sources with simultaneous working fluid selection

2017 ◽  
Vol 142 ◽  
pp. 1950-1970 ◽  
Author(s):  
Mirko Z. Stijepovic ◽  
Athanasios I. Papadopoulos ◽  
Patrick Linke ◽  
Vladimir Stijepovic ◽  
Aleksandar S. Grujic ◽  
...  
Keyword(s):  
System Performance ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Heat Sources ◽  
Cycle System ◽  
Working Fluid Selection

Working fluid selection and preliminary design of a solar organic Rankine cycle system

2014 ◽  
Vol 34 (2) ◽  
pp. 619-626 ◽  
Author(s):  
Wei Gao ◽  
Haiwang Li ◽  
Guoqiang Xu ◽  
Yongkai Quan
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Preliminary Design ◽  
Cycle System ◽  
Working Fluid Selection

scholarly journals Working fluid selection for organic Rankine cycle power generation using hot produced supercritical CO2 from a geothermal reservoir

2019 ◽  
Vol 149 ◽  
pp. 1287-1304 ◽  
Author(s):  
Xingchao Wang ◽  
Edward K. Levy ◽  
Chunjian Pan ◽  
Carlos E. Romero ◽  
Arindam Banerjee ◽  
...  
Keyword(s):  
Power Generation ◽  
Supercritical Co2 ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Geothermal Reservoir ◽  
Working Fluid ◽  
Working Fluid Selection ◽  
Selection For

Performance Investigation of Solar Organic Rankine Cycle System With Zeotropic Working Fluid Mixtures for Use in Micro-Cogeneration

2021 ◽  
Vol 143 (9) ◽  
Author(s):  
Wahiba Yaïci ◽  
Evgueniy Entchev ◽  
Pouyan Talebizadehsardari ◽  
Michela Longo
Keyword(s):  
Low Temperature ◽  
Power Output ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Condensation Temperature ◽  
Source Temperature ◽  
Thermodynamic Performance ◽  
Net Power Output ◽  
Cycle Efficiency

Abstract Overall, there are numerous sustainable sources of renewable, low-temperature heat, principally solar energy, geothermal energy, and energy produced from industrial wastes. Extended utilization of these low-temperature alternatives has a certain capacity of decreasing fossil fuel use with its associated very hazardous greenhouse gas emissions. Researchers have commonly recognized the organic Rankine cycle (ORC) as a feasible and suitable system to produce electrical power from renewable sources based on its advantageous use of volatile organic fluids as working fluids (WFs). Researchers have similarly shown an affinity to the exploitation of zeotropic mixtures as ORC WFs due to their capability to enhance the thermodynamic performance of ORC systems, an achievement supported by improved fits of the temperature profiles of the WF and the heat source/sink. This paper determines both the technical feasibility and the benefits of using zeotropic mixtures as WFs by means of a simulation study of an ORC system. This study analyzes the thermodynamic performance of ORC systems using zeotropic WF mixtures to produce electricity driven by low-temperature solar heat sources for use in buildings. A thermodynamic model is created with an ORC system with and without a regenerator. Five zeotropic mixtures with diverse compositions between 0 and 1 in 0.2 increments of R245fa/propane, R245fa/hexane, R245fa/heptane, pentane/hexane, and isopentane/hexane are assessed and compared with identify the best blends of mixtures that are able to produce superior efficiency in their system cycles. Results disclosed that R245fa/propane (0.4/0.6) with regenerator produces the highest net power output of 7.9 kW and cycle efficiency of 9.4% at the operating condition with a hot source temperature of 85 °C. The study also investigates the effects of the volume flow ratio, and evaporation and condensation temperature glide on the ORC’s thermodynamic performance. Following a thorough analysis of each mixture, R245fa/propane is chosen for a parametric study to examine the effects of operating factors on the system’s efficiency and sustainability index. It was found that the highest cycle efficiency and highest second law cycle efficiency of around 10.5% and 84.0%, respectively, were attained with a mass composition of 0.6/0.4 at the hot source temperature of 95 °C and cold source temperature of 20 °C with a net power output of 9.6 kW. Moreover, results revealed that for zeotropic mixtures, there is an optimal composition range within which binary mixtures are tending to work more efficiently than the component pure fluids. In addition, a significant increase in cycle efficiency can be achieved with a regenerative ORC, with cycle efficiency in the range 3.1–9.8% versus 8.6–17.4% for ORC both without and with regeneration, respectively. In conclusion, utilizing zeotropic mixtures may well expand the restriction faced in choosing WFs for solar-powered ORC-based micro-combined heat and power (CHP) systems.

Zeotropic working fluid selection for an organic rankine cycle bottoming with a marine engine

Energy ◽  
2022 ◽  
pp. 123097
Author(s):  
Enhua Wang ◽  
Zhang Mengru ◽  
Meng Fanxiao ◽  
Hongguang Zhang
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Marine Engine ◽  
Working Fluid Selection ◽  
Selection For
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