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.

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.

scholarly journals Assessment of a Geothermal Combined System with an Organic Rankine Cycle and Multi-effect Distillation Desalination

2022 ◽  
Author(s):  
Aida Farsi ◽  
Marc A. Rosen
Keyword(s):  
Environmental Impact ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Hot Water ◽  
Exergy Destruction ◽  
Destruction Rate ◽  
Sustainability Analysis ◽  
Environment Temperature ◽  
Cycle Systems ◽  
Reference Environment

AbstractAn analysis is reported of a geothermal-based electricity-freshwater system in which an organic Rankine cycle is integrated with a multi-effect distillation desalination unit. The system is driven by geothermal hot water extracted from the production well. Mass, energy, entropy, and exergy rate balances are written for all system components, as are energy and exergy efficiency expressions for each subsystem. The exergy destruction rate associated with the temperature and chemical disequilibrium of the freshwater and brine with the reference environment are taken into account to reveal accurate results for irreversibility sources within the desalination process. The developed thermodynamic model is simulated using thermodynamic properties of the working fluids (i.e., ammonia, seawater, distillate, and brine) at each state point. A sustainability analysis is performed that connects exergy and environmental impact concepts. That assessment expresses the extent of the contribution of the system to sustainable development and reduced environmental impact, using exergy methods. Results of the sustainability analysis indicate that, with an increase in the reference environment temperature from 20 to 35 $$^\circ{\rm C}$$ ∘ C , the exergy destruction rate decreases for the multi-effect distillation and organic Rankine cycle systems respectively from 6474 to 4217 kW and from 16,270 to 13,459 kW. Also, the corresponding sustainability index for the multi-effect distillation and organic Rankine cycle systems increases from 1.16 to 1.2 and 1.5–1.6, respectively, for the same increase in reference environment temperature.

Energy and Exergy Assessments of a New Trigeneration System Based on Organic Rankine Cycle and Biomass Combustor

2010 ◽  
Author(s):  
Fahad A. Al-Sulaiman ◽  
Feridun Hamdullahpur ◽  
Ibrahim Dincer
Keyword(s):  
Electrical Power ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exergy Efficiency ◽  
Heating Process ◽  
Inlet Temperature ◽  
Exergy Destruction ◽  
Energy And Exergy ◽  
Pump Inlet ◽  
Exergy Analyses

In this paper, energy and exergy analyses of a trigeneration system based on an organic Rankine cycle (ORC) and a biomass combustor are presented. This trigeneration system consists of a biomass combustor to provide heat input to the ORC, an ORC for power production, a single-effect absorption chiller for cooling process and a heat exchanger for heating process. The system is designed to produce around 500 kW of electricity. In this study, four cases are considered, namely, electrical-power, cooling-cogeneration, heating-cogeneration and trigeneration cases. The effects of changing ORC pump inlet temperature and turbine inlet pressure on different key parameters have been examined to evaluate the performance of the trigeneration system. These parameters are energy and exergy efficiencies, electrical to cooling ratio and electrical to heating ratio. Moreover, exergy destruction analysis is presented to show the main sources of exergy destruction and the contribution of each source to the exergy destruction. The study shows that there are significant improvements in energy and exergy efficiencies when trigeneration is used as compared to electrical power. The results show that the maximum efficiencies for the cases considered in this study are as follows: 14.0% for electrical power, 17.0% for cooling cogeneration, 87.0% for heating cogeneration and 89.0% for trigeneration. On other hand, the maximum exergy efficiency of the ORC is 13.0% while the maximum exergy efficiency of the trigeneration system is 28.0%. In addition, this study reveals that the main sources of exergy destruction are the biomass combustor and ORC evaporator.

Waste Heat Recovery From Closed Brayton Cycle Using Organic Rankine Cycle: Thermodynamic Analysis

2009 ◽  
Author(s):  
Mortaza Yari
Keyword(s):  
Waste Heat ◽  
Pressure Ratio ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Exergy Destruction ◽  
Evaporator Temperature ◽  
Destruction Rate

This study examines the performance of a gas-cooled nuclear power plant with closed Brayton cycle (CBC) combined with an organic Rankine cycle (ORC) plant, as well as the irreversibility within the system. Individual models have been developed for each component, through applications of the first and second laws of thermodynamics. The overall system performance is then analyzed by employing individual models and further application of thermodynamic laws for the entire cycle, to evaluate the thermal efficiency and entropy production of the plant. The effects of the turbine inlet temperature, compressor pressure ratio, evaporator temperature, and temperature difference in the evaporator on the combined cycle first-law, second-law efficiency and exergy destruction rate are studied. Finally optimization of the combined cycle in a systematic way has been developed and discussed. It was found that the combined cycle first-law efficiency is about 9.5–10.1% higher than the simple CBC cycle. Also, the exergy destruction rate for the GT-MHR/ORC combined cycle, is about 6.5–8.3% lower than that of the GT-MHR cycle.

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