Exergoeconomic comparison and optimization of organic Rankine cycle, trilateral Rankine cycle and transcritical carbon dioxide cycle for heat recovery of low-temperature geothermal water

2019 ◽  
Vol 233 (8) ◽  
pp. 1068-1084 ◽  
Author(s):  
Afsaneh Noroozian ◽  
Abbas Naeimi ◽  
Mokhtar Bidi ◽  
Mohammad Hossein Ahmadi
Keyword(s):  
Sensitivity Analysis ◽  
Low Temperature ◽  
Heat Source ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Cost Ratio ◽  
Exergetic Efficiency ◽  
Geothermal Heat ◽  
Product Cost

Depleting fossil fuel resources and the horrible environmental impacts due to burning fossil fuels emphasize the importance of using renewable energy resources such as geothermal and solar energies. This paper compares performance of CO2 transcritical cycle, organic Rankine cycle, and trilateral Rankine cycle using a low-temperature geothermal heat source. Thermodynamic analysis, exergetic analysis, economic analysis, and exergoeconomic analysis are applied for each of the aforementioned cycles. In addition, a sensitivity analysis is performed on the system, and the effects of geothermal heat source temperature, evaporator pinch point temperature, and turbine inlet pressure on the cycle's performance are evaluated. Finally, the systems are optimized in order to minimize product cost ratio and maximize exergetic efficiency by using the genetic algorithm. Results indicate that the maximum thermal efficiency is approximately 13.03% which belongs to organic Rankine cycle with R123 as working fluid. CO2 cycle has the maximum exergetic efficiency, equals to 46.13%. The minimum product cost ratio refers to the organic Rankine cycle with R245fa as working fluid. Moreover, sensitivity analysis shows that increasing geothermal heat source temperature results in higher output power, product cost ratio, and exergy destruction ratio in all cycles.

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.

scholarly journals Thermodynamic, Economic and Sustainability Analysis of Solar Organic Rankine Cycle System with Zeotropic Working Fluid Mixtures for Micro-Cogeneration in Buildings

2020 ◽  
Vol 10 (21) ◽  
pp. 7925
Author(s):  
Wahiba Yaïci ◽  
Evgueniy Entchev ◽  
Pouyan Talebizadehsardari ◽  
Michela Longo
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Optimum Operating ◽  
Working Fluid ◽  
Condensation Temperature ◽  
Fluid Mixtures ◽  
Thermodynamic Performance ◽  
Cycle Efficiency

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 suitable system to generate electrical power from renewable sources based on its beneficial usage of volatile organic fluids as working fluids (WFs). In recent times, researchers have also shown a preference towards deployment of zeotropic mixtures as ORC WFs because of their capacity to improve thermodynamic performance of ORC systems, a feat enabled through the greater matching of the temperature profiles of the WF and the heat source/sink. This paper demonstrates the thermodynamic, economic and sustainability feasibility, and the notable advantages of using zeotropic mixtures as WFs through a simulation study of an ORC system. The study examines first the thermodynamic performance of ORC systems using zeotropic mixtures to generate electricity powered by a low-temperature solar heat source for building applications. A thermodynamic model is developed with a solar-driven ORC system both with and excluding a regenerator. Twelve zeotropic mixtures with varying compositions are evaluated and compared to identify the best combinations of mixtures that can yield high performance and high efficiency in their system cycles. The study also examines the effects of the volume flow ratio, and evaporation and condensation temperature glides on the ORC’s thermodynamic performance. Following a detailed analysis of each mixture, R245fa/propane and butane/propane are selected for parametric study to investigate the influence of operating parameters on the system’s efficiency and sustainability index. For zeotropic mixtures, results disclosed 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 substantial enhancement in cycle efficiency can be obtained by 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 revealed that exploiting zeotropic mixtures could enlarge the limitation experienced in selecting WFs for low-temperature solar ORCs. Moreover, a detailed economic with a sensitivity analysis of the solar ORC system was performed to evaluate the cost of the electricity and other economic criteria. The outcome of this investigation should be useful in the thermo-economic feasibility assessments of solar-driven ORC systems using working fluid mixtures to find the optimum operating range for maximum performance and minimum cost.

Comparative assessment of Organic Rankine Cycle integration for low temperature geothermal heat source applications

Energy ◽  
2016 ◽  
Vol 102 ◽  
pp. 473-490 ◽  
Author(s):  
Muhammad Imran ◽  
Muhammad Usman ◽  
Byung-Sik Park ◽  
Youngmin Yang
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Comparative Assessment ◽  
Geothermal Heat

A Computer Program for Working Fluid Selection of Low Temperature Organic Rankine Cycle

2015 ◽  
Author(s):  
Muhammad Ansab Ali ◽  
Tariq Saeed Khan ◽  
Ebrahim Al Hajri ◽  
Zahid H. Ayub
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Computer Program ◽  
Fossil Fuels ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Power Production ◽  
Working Fluid ◽  
Low Grade

Fossil fuels are continuously depleting while the global energy demand is growing at a fast rate. Additionally, fossil fuels based power plants contribute to environmental pollution. Search for alternate energy resources and use of industrial waste heat for power production are attractive topics of interest these days. One way of enhancing power production and decreasing the environmental impact is by recuperating and utilizing low grade thermal energy. In recent years, research on use of organic Rankine cycle (ORC) has gained popularity as a promising technology for conversion of heat into useful work or electricity. Due to simple structure of ORC system, it can be easily integrated with any energy source like geothermal energy, solar energy and waste heat. A computer program has been developed in engineering equation solver (EES) environment that analyzes and selects appropriate working fluid for organic Rankine cycle design based on available heat sources. For a given heat source, the program compares energy and exergy performance of various working fluids. The program also includes recuperator performance analysis and compares its effectiveness on the overall thermal performance of the Rankine cycle. This program can assist in preliminary design of ORC with respect to best performing refrigerant fluid selection for the given low temperature heat source.

scholarly journals Experimental investigation and performance analysis of an Organic Rankine Cycle for low-temperature heat to electricity generation

2019 ◽  
Vol 14 (4) ◽  
pp. 500-507
Author(s):  
Lili Wei ◽  
Zhenjun Ma ◽  
Xuemei Gong ◽  
Xiujuan Guo
Keyword(s):  
Energy Efficiency ◽  
Low Temperature ◽  
Heat Source ◽  
Electricity Generation ◽  
Extraction Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Energy And Exergy ◽  
Temperature Heat

Abstract This paper presents experimental investigation of low-temperature heat to electricity generation system based on Organic Rankine Cycle (ORC) using R152a as the working fluid. Both energy efficiency and exergy efficiency were analyzed based on the experiments. Although energy efficiency was low to 5.0% when the evaporating and cooling temperatures were 65°C and 11°C, respectively, the exergy efficiency reached 25%, which showed great competitiveness among low-temperature heat utilization technologies. To reveal the energy recovery proportion from the waste heat, both energy extraction efficiency and exergy extraction efficiency as well as energy and exergy loss paths were analyzed. When the heat source was 65°C, 14.9% of the maximum possible thermal energy in the heat source was absorbed by the organic working fluid, and 10.7% was transferred to the cooling medium. The power output contributed 0.64%. A total of 1.8% of the exergy in the heat stream flowed to the cooling medium. The start-up work takes dramatically 0.16% and 1.7% of energy and exergy, respectively. Other energy and exergy loss occurs due to the irreversibility of the heat transfer process and expansion process. Cascade ORC system could enlarge the temperature difference of the heat stream and raise the power output. However, the energy efficiency of the multi-stage ORC system is lower than single-stage system, since there was a downward trend of the temperature of heat source for the latter stage. ORC cycle can lower the temperature of heat source to 45°C.

scholarly journals Thermodynamic analysis of a Carbon Carrier Cycle (CCC) for low temperature heat recovery

2021 ◽  
Vol 238 ◽  
pp. 01002
Author(s):  
Diego Micheli ◽  
Mauro Reini ◽  
Rodolfo Taccani
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Heat Recovery ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Performance Comparison ◽  
Working Fluid ◽  
Power Cycle ◽  
Carbon Carrier ◽  
Temperature Heat

The aim of the paper is to study the thermodynamic behavior of a non-conventional power cycle, named Carbon Carrier Cycle (CCC), which is expected to obtain interesting performance with low temperature heat source. The CCC may be regarded as derived from an absorption machine, where an expander replaces the condenser, the throttling valve and the evaporator. The working fluid is a mixture of CO2 and a proper absorber. In the paper, the thermodynamic model of this kind of cycles is described, and the results obtained considering Acetone as the absorber are discussed. A first performance comparison is then conducted with a more conventional Organic Rankine Cycle (ORC).

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