scholarly journals Energy, Exergy, Exergoeconomic and Exergoenvironmental Impact Analyses and Optimization of Various Geothermal Power Cycle Configurations

Entropy ◽  
2021 ◽  
Vol 23 (11) ◽  
pp. 1483
Author(s):  
Moein Shamoushaki ◽  
Mehdi Aliehyaei ◽  
Marc A. Rosen
Keyword(s):  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exergy Destruction ◽  
Power Cost ◽  
Electricity Cost ◽  
Bee Colony ◽  
Sensitivity Assessment ◽  
Binary Cycle ◽  
Economic Perspectives ◽  
Period Decrease

Energy, exergy, and exergoeconomic evaluations of various geothermal configurations are reported. The main operational and economic parameters of the cycles are evaluated and compared. Multi-objective optimization of the cycles is conducted using the artificial bee colony algorithm. A sensitivity assessment is carried out on the effect of production well temperature variation on system performance from energy and economic perspectives. The results show that the flash-binary cycle has the highest thermal and exergy efficiencies, at 15.6% and 64.3%, respectively. The highest generated power cost and pay-back period are attributable to the simple organic Rankine cycle (ORC). Raising the well-temperature can increase the exergy destruction rate in all configurations. However, the electricity cost and pay-back period decrease. Based on the results, in all cases, the exergoenvironmental impact improvement factor decreases, and the temperature rises. The exergy destruction ratio and efficiency of all components for each configuration are calculated and compared. It is found that, at the optimum state, the exergy efficiencies of the simple organic Rankine cycle, single flash, double flash, and flash-binary cycles respectively are 14.7%, 14.4%, 12.6%, and 14.1% higher than their relevant base cases, while the pay-back periods are 10.6%, 1.5% 1.4%, and 0.6% lower than the base cases.

scholarly journals Energy and Exergy Analysis of Combined Organic Rankine Cycle-Single and Dual Evaporator Vapor Compression Refrigeration Cycle

2019 ◽  
Vol 9 (23) ◽  
pp. 5028 ◽  
Author(s):  
Pektezel ◽  
Acar
Keyword(s):  
Exergy Analysis ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Exergy Destruction ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Vapor Compression Refrigeration

This paper presents energy and exergy analysis of two vapor compression refrigeration cycles powered by organic Rankine cycle. Refrigeration cycle of combined system was designed with single and dual evaporators. R134a, R1234ze(E), R227ea, and R600a fluids were used as working fluids in combined systems. Influences of different parameters such as evaporator, condenser, boiler temperatures, and turbine and compressor isentropic efficiencies on COPsys and ƞex,sys were analyzed. Second law efficiency, degree of thermodynamic perfection, exergy destruction rate, and exergy destruction ratio were detected for each component in systems. R600a was determined as the most efficient working fluid for proposed systems. Both COPsys and ƞex,sys of combined ORC-single evaporator VCR cycle was detected to be higher than the system with dual evaporator.

scholarly journals Investigating the System Behaviors of a 10 kW Organic Rankine Cycle (ORC) Prototype Using Plunger Pump and Centrifugal Pump

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1141 ◽  
Author(s):  
Xin Wang ◽  
Yong-qiang Feng ◽  
Tzu-Chen Hung ◽  
Zhi-xia He ◽  
Chih-Hung Lin ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Heat Input ◽  
Electrical Power ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Utilization Rate ◽  
Exergy Destruction ◽  
Plunger Pump ◽  
Pressure Drops ◽  
Cold Source

Based on a 10-kW organic Rankine cycle (ORC) experimental prototype, the system behaviors using a plunger pump and centrifugal pump have been investigated. The heat input is in the range of 45 kW to 82 kW. The temperature utilization rate is defined to appraise heat source utilization. The detailed components’ behaviors with the varying heat input are discussed, while the system generating efficiency is examined. The exergy destruction for the four components is addressed finally. Results indicated that the centrifugal pump owns a relatively higher mass flow rate and pump isentropic efficiency, but more power consumption than the plunger pump. The evaporator pressure drops are in the range of 0.45–0.65 bar, demonstrating that the pressure drop should be considered for the ORC simulation. The electrical power has a small difference using a plunger pump and a centrifugal pump, indicating that the electric power is insensitive on the pump types. The system generating efficiency for the plunger pump is approximately 3.63%, which is 12.51% higher than that of the centrifugal pump. The exergy destruction for the evaporator, expander, and condenser is almost 30%, indicating that enhancing the temperature matching between the system and the heat (cold) source is a way to improve the system performance.

scholarly journals Performance comparison of the solar-driven supercritical organic Rankine cycle coupled with the vapour-compression refrigeration cycle

Clean Energy ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 476-491
Author(s):  
Yunis Khan ◽  
Radhey Shyam Mishra
Keyword(s):  
Thermal Efficiency ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Coefficient Of Performance ◽  
Solar Irradiation ◽  
Working Fluid ◽  
Refrigeration Cycle ◽  
Exergy Destruction ◽  
Cogeneration System ◽  
Vapour Compression

Abstract In this study, a parametric analysis was performed of a supercritical organic Rankine cycle driven by solar parabolic trough collectors (PTCs) coupled with a vapour-compression refrigeration cycle simultaneously for cooling and power production. Thermal efficiency, exergy efficiency, exergy destruction and the coefficient of performance of the cogeneration system were considered to be performance parameters. A computer program was developed in engineering equation-solver software for analysis. Influences of the PTC design parameters (solar irradiation, solar-beam incidence angle and velocity of the heat-transfer fluid in the absorber tube), turbine inlet pressure, condenser and evaporator temperature on system performance were discussed. Furthermore, the performance of the cogeneration system was also compared with and without PTCs. It was concluded that it was necessary to design the PTCs carefully in order to achieve better cogeneration performance. The highest values of exergy efficiency, thermal efficiency and exergy destruction of the cogeneration system were 92.9%, 51.13% and 1437 kW, respectively, at 0.95 kW/m2 of solar irradiation based on working fluid R227ea, but the highest coefficient of performance was found to be 2.278 on the basis of working fluid R134a. It was also obtained from the results that PTCs accounted for 76.32% of the total exergy destruction of the overall system and the cogeneration system performed well without considering solar performance.

scholarly journals Investigation of an Innovative Cascade Cycle Combining a Trilateral Cycle and an Organic Rankine Cycle (TLC-ORC) for Industry or Transport Application

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3032 ◽  
Author(s):  
Xiaoli Yu ◽  
Zhi Li ◽  
Yiji Lu ◽  
Rui Huang ◽  
Anthony Roskilly
Keyword(s):  
High Temperature ◽  
System Performance ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Working Fluid ◽  
Second Law ◽  
Exergy Destruction ◽  
Second Law Analysis ◽  
Net Power Output

An innovative cascade cycle combining a trilateral cycle and an organic Rankine cycle (TLC-ORC) system is proposed in this paper. The proposed TLC-ORC system aims at obtaining better performance of temperature matching between working fluid and heat source, leading to better overall system performance than that of the conventional dual-loop ORC system. The proposed cascade cycle adopts TLC to replace the High-Temperature (HT) cycle of the conventional dual-loop ORC system. The comprehensive comparisons between the conventional dual-loop ORC and the proposed TLC-ORC system have been conducted using the first and second law analysis. Effects of evaporating temperature for HT and Low-Temperature (LT) cycle, as well as different HT and LT working fluids, are systematically investigated. The comparisons of exergy destruction and exergy efficiency of each component in the two systems have been studied. Results illustrate that the maximum net power output, thermal efficiency, and exergy efficiency of a conventional dual-loop ORC are 8.8 kW, 18.7%, and 50.0%, respectively, obtained by the system using cyclohexane as HT working fluid at THT,evap = 470 K and TLT,evap = 343 K. While for the TLC-ORC, the corresponding values are 11.8 kW, 25.0%, and 65.6%, obtained by the system using toluene as a HT working fluid at THT,evap = 470 K and TLT,evap = 343 K, which are 34.1%, 33.7%, and 31.2% higher than that of a conventional dual-loop ORC.

scholarly journals Análise Exergoeconômica de um sistema de trigeração de energia operando com um Ciclo Rankine Orgânico

2021 ◽  
Vol 1 (54) ◽  
pp. 20
Author(s):  
Thiago De Souza Figueredo ◽  
João Luiz De Medeiros Neto ◽  
Adriano Da Silva Marques ◽  
Carlos Antônio Cabral Dos Santos
Keyword(s):  
Steam Generator ◽  
Organic Rankine Cycle ◽  
Industrial Process ◽  
Rankine Cycle ◽  
Exergy Destruction ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
Simple Effect ◽  
Absorption Refrigeration System ◽  
Residual Heat

<span class="fontstyle0">This work presents the results of the energetic, exergetic and exergoeconomic evaluation of a trigeneration system which is composed of an Organic Rankine Cycle (ORC), a simple effect Absorption Refrigeration System (SRA) and a boiler. The proposed system is driven by the residual heat of an industrial process. A computational code was developed on the EES (Engineering Equation Solver) platform to solve the thermodynamic and exergoeconomic equation of each equipment. The SPECO method (Specific Exergy Costing) was used for the exergoeconomic evaluation. Results indicated which equipment needs optimization in order of priority. The results show that the greatest destruction of exergy occurs in the ORC steam generator (56% of the total), followed by the condenser that presented an exergy destruction of 33%. Conversely, the pump and expander performed better, with low exergy destruction values. The results of the exergoeconomic evaluation also indicate that the steam generator and condenser from ORC need to be optimized before any other equipment, as they obtained the lowest values of the exergoeconomic factor (f</span><span class="fontstyle0">k</span><span class="fontstyle0">) and the highest values of the specific relative cost (r</span><span class="fontstyle0">k</span><span class="fontstyle0">).</span> <br /><br />

An Energetic and Exergoeconomic Analysis of a CCHP System With Micro Gas Turbine, Organic Rankine Cycle and Ammonia-Water Absorption Refrigeration Cycle

2019 ◽  
Author(s):  
Ganesh V. Doiphode ◽  
Hamidreza Najafi
Keyword(s):  
Residential Buildings ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Rate Equations ◽  
Inlet Temperature ◽  
Refrigeration Cycle ◽  
Exergy Destruction ◽  
Detailed Model ◽  
Ammonia Water ◽  
Exergoeconomic Analysis

Abstract Combined cooling, heating and power generation (CCHP) systems can be utilized for commercial or multi-family residential buildings as efficient and reliable means to satisfy building power requirements and thermal loads. In the present paper, a CCHP system consist of a Bryton cycle, an Organic Rankine cycle (ORC) and an absorption Ammonia-water cycle is considered. A detailed model is developed via MATLAB to assess the performance of the considered cycle from energy, exergy and economic perspectives. Appropriate ranges for inputs are considered and the first law efficiency, second law efficiency and ECOP of the cycle are determined as 77.17%, 33.18% and 0.31 respectively for the given inputs. Exergy destruction rates are found to be greatest primarily in the generator and the absorber of refrigeration cycle followed by the combustion chamber. The total exergy destruction rate in the system is found as 5311.51 kW. The exergoeconomic analysis is performed using SPECO approach to evaluate cost flow rate equations of the complete system and its individual components. Summation of capital investment cost rates and cost rates associated with the exergy destruction for the whole system is found as $18.245 per hour. A parametric study is also performed to provide an understanding on the effect of total pressure ratio and turbine inlet temperature of ORC on the performance of the system.

Economic Feasibility Study of a Small Scale Organic Rankine Cycle System in Waste Heat Recovery Application

2010 ◽  
Author(s):  
Bertrand F. Tchanche ◽  
Sylvain Quoilin ◽  
Sebastien Declaye ◽  
Georges Papadakis ◽  
Vincent Lemort
Keyword(s):  
Thermodynamic Model ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Payback Period ◽  
Working Fluid ◽  
Small Scale ◽  
Electricity Cost

The Organic Rankine Cycle (ORC) appears progressively as a promising solution to recover waste heat energy from thermal processes for electricity generation. A prototype of small-scale ORC has been built and successfully tested at the University of Lie`ge. It uses R-245fa and R-123 as working fluid, and an oil-free scroll compressor adapted to run in expander mode. Thermodynamic model of the system was derived and validated for performance prediction. The validated thermodynamic model is used to optimize the operation of the small ORC in waste heat recovery application (ORC-WHR). For exhaust gases at 180 °C and a mass flow rate of 0.21 kg/s, a maximum net power output of 2 kWe is obtained for an evaporator pressure of 11.84 bar. The cycle thermal efficiency is 8.23 and the recuperation efficiency, 66.32%. Based on the aforementioned conditions, the economic assessment of small scale ORC-WHR was carried out using economic criteria such as levelized electricity cost (LEC), Net present value (NPV) and depreciated payback period (DPP). For a 2kWe ORC-WHR, the specific installed cost is 5775 €/kW with a LEC of 13.27 c€/kWh while for a 50 kWe, the specific installed cost is about 3034 €/kW and the LEC, 7c€/kWh. For an electricity unit price of 20 c€/kWh, the payback period of a 2 kWe system is 6 years while it is 2.5 years for a 50 kWe system. It is concluded from the study that recovering the waste heat by way of ORCs is technically and economically feasible. As recycled energy, waste heat has the same advantages as renewable energy and should benefit from the same legislative conditions (Feed-in-Laws).

scholarly journals Thermodynamic, Exergy and Environmental Impact Assessment of S-CO2 Brayton Cycle Coupled with ORC as Bottoming Cycle

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2259 ◽  
Author(s):  
Edwin Espinel Blanco ◽  
Guillermo Valencia Ochoa ◽  
Jorge Duarte Forero
Keyword(s):  
Environmental Impact ◽  
Impact Assessment ◽  
Environmental Impact Assessment ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Thermal Design ◽  
Inlet Temperature ◽  
Exergy Destruction ◽  
Combined System ◽  
The Sustainable Development

In this article, a thermodynamic, exergy, and environmental impact assessment was carried out on a Brayton S-CO2 cycle coupled with an organic Rankine cycle (ORC) as a bottoming cycle to evaluate performance parameters and potential environmental impacts of the combined system. The performance variables studied were the net power, thermal and exergetic efficiency, and the brake-specific fuel consumption (BSFC) as a function of the variation in turbine inlet temperature (TIT) and high pressure (PHIGH), which are relevant operation parameters from the Brayton S-CO2 cycle. The results showed that the main turbine (T1) and secondary turbine (T2) of the Brayton S-CO2 cycle presented higher exergetic efficiencies (97%), and a better thermal and exergetic behavior compared to the other components of the System. Concerning exergy destruction, it was found that the heat exchangers of the system presented the highest exergy destruction as a consequence of the large mean temperature difference between the carbon dioxide, thermal oil, and organic fluid, and thus this equipment presents the greatest heat transfer irreversibilities of the system. Also, through the Life Cycle Analysis, the potential environmental impact of the system was evaluated to propose a thermal design according to the sustainable development goals. Therefore, it was obtained that T1 was the component with a more significant environmental impact, with a maximum value of 4416 Pts when copper is selected as the equipment material.

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