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This study presents the energetic and energetic analysis of the heat pump cycle, used for heating residential spaces. The heat pump is of the air-water type, taking heat at the level of the evaporator from the environment. The working fluids used are: R1233zd(E), R1234ze, R152a, R1234yf. Exergy analysis is used as a research tool. Based on the exergy analysis, the identification of malfunctions at the level of each device and process can be easily achieved. The study shows that the working fluid R1233zd(E) presents the highest coefficient of performance and the highest exergetic efficiency. [ABSTRACT FROM AUTHOR]

In this study, thermodynamic analysis for integration of a PEMFC with an organic Rankin cycle, and an ejector expansion vapor compression refrigeration system is presented. The input energy of the system is supplied by the waste heat of a PEMFC. Energy and exergy analysis is performed on each system component and compared with a simple ORC-VCR without an ejector. The results show that employing the ejector can improve the refrigeration capacity, energy efficiency, and exergy efficiency by 18.88%, 12.29 %, and 12.27%, respectively, compared to a simple ORC-VCR system. Moreover, the overall energy and exergy efficiency of the system is 33.43% and 5.46% higher than a standalone PEM fuel cell. Furthermore, in the parametric study, the effect of condenser temperature, evaporator temperature, ejector efficiency, PEMFC operating temperature, current density, and PEMFC operating pressure on the energy efficiency, exergy efficiency, and refrigeration capacity of the system is investigated. [ABSTRACT FROM AUTHOR]

This study focuses on a combined power generation and cooling system comprising an organic Rankine cycle and a dual evaporator cooling cycle. A parametric study based on exergy analysis was performed using different organic fluids: R134a, R290 and R600 in order to determine its optimal operation. The results show that the thermodynamic parameters that were studied, such as the operating temperature of the evaporator of the ORC cycle and the dual evaporator cycle on the performance of the system are of great importance and improve the performance of the combined system including energy efficiency and exergy efficiency using R600 as the working fluid. Furthermore, the results indicate that using R600 as the working fluid for both cycles improve the system performance. [ABSTRACT FROM AUTHOR]

• Zeotropic mixture of Hexane and R245fa is used as the working fluid. • Condenser and ORC evaporator contribute 75.3% to total exergy destruction. • Energy and exergetic performance of the system is maximum at mass fraction of 0.5. • The system can achieve the exergetic efficiency of 58% at optimal condition. In this study, a multi evaporator vapor-compression refrigeration (mVCR) system driven by Organic Rankine Cycle (ORC) is proposed as a refrigeration system for supermarkets, restaurants, etc. The system is analyzed for its thermodynamic performance in terms of coefficient of performance (COP s) and exergetic efficiency (η ex). A zeotropic mixture of hexane and R245fa is used as working fluid over pure fluid to assess its impact on the thermodynamic performance of the system. Moreover, the system is optimized using an evolutionary algorithm called genetic algorithm (GA) to determine the optimal values of the operating parameters for the maximum exergetic efficiency of the system. The results indicate that COP s and η ex are maximum at the mass fraction of 0.5 of the zeotropic mixture. The maximum values of COP s and η ex are 0.425 and 31.1% respectively. The system can achieve an exergetic efficiency of 58% at the optimal set of operating parameters. The corresponding optimal values of the temperature of the ORC evaporator, VCR evaporator 1, VCR evaporator 2, and the condenser are 388 K, 268 K, 268 K, and 303 K respectively. [ABSTRACT FROM AUTHOR]

• Novel condenser outlet split cycle with the presence of two ejectors working in different temperatures has been investigated. • Exergy and energy analysis has been performed. • COP enhancement of the proposed cycle at different condenser temperature has increased from 8.3 to 14.1%. In this paper, the possibility of performance enhancement of a new Condenser Outlet Split (COS) cycle with the presence of two ejectors working in different temperatures is investigated. In order to enhance the cycle performance, an auxiliary ejector-expansion refrigeration cycle equipped with a separator and a secondary ejector has been employed, resulting in further performance improvement on both exergy and energy analyses on the different condenser and evaporator temperatures. The thermodynamic equations of each component in the standard and proposed cycles have been solved in EES software. The auxiliary cycle boosted the pressure at the inlet of the secondary nozzle of the main ejector leads to a better performance of the proposed cycle. Through energy analysis, compressor work recovery increased by 12% and the coefficient of performance showed up to 14.1% enhancement. Through exergy analysis, our proposed cycle have been produced 6.8% reduction in exergy destruction compared to the standard cycle, and the total exergy performance of the given system can be increased from 8.2 to 14%. [ABSTRACT FROM AUTHOR]

• AEA was used to separate azeotropic mixture of ACN/EtOH/H2O via TCED process. • A superstructure TCED with four-parallel evaporator ORC system is built. • Four advantageous working fluids are selected to enhance the performance of ORC. • The intensification process shows better energy-saving and economic performance. The energy analysis and optimization of process system aiming to solve the problems of high consumption, low efficiency and unreasonable use of energy in the process of energy utilization has been widely researched and developed in recent decades. In this work, advanced exergy analysis was carried out for the triple-column extractive distillation (TCED) process separating ternary azeotropic mixture of ACN/EtOH/H2O. The total exergy destruction is 1097.69 KW. The avoidable exergy destruction, is 29.20%, mainly caused by the cooler and three condensers. Based on the thermodynamic analysis results, a superstructure TCED with four-parallel evaporator organic Rankine cycles (FPE-ORC) system is proposed, four working fluids were selected. An improved genetic algorithm is used to obtain the optimal operating parameters of the ORC system by using the exergy efficiency and annual net profit (ANP) of the ORC as two conflict objective functions. Compare with existing process, the FPE-ORC system with working fluid R600 provides the highest exergy efficiency of 12.27%, with working fluid R600a leads to the best economic benefit of 6.43 E + 4 dollar/year. [ABSTRACT FROM AUTHOR]