Sharif Digital Repository

In this study, a year-round dynamic simulation of a Combined Cooling, Heating and Power generation (CCHP) system has been performed. The proposed system is composed of an ejector cooling system, an Organic Rankine Cycle (ORC), a solar collector field, heat exchangers and hot and cold storage tanks. It is considered that, a portion of the system input energy is provided by a solar collector field and an auxiliary heater supplies the extra required energy. The dynamic simulation of the introduced CCHP system is performed. The developed model is used to evaluate a year-round performance of the system for a residential building located in Tehran. The obtained results indicated that the proposed... 

This article works with performance improvement of the conventional combined cooling/power (CCP) cycles to augment energy and exergy efficiencies of the previous systems. For this target, a conceptual configuration of cascade ejector refrigeration system (CERS) is proposed and is joined with organic Rankine cycle (ORC) to generate power and cooling outputs. The introduced CCP system can generate cooling load at two various temperatures for freezing and air-conditioning usages. For power sub-cycle, basic ORC and recuperative ORC with turbine bleeding are selected as topping cycles. Thermodynamic and exergoeconomic assessments of the cycles are done, leading to provision of the working... 

The main focus of this paper is to present thermodynamic and economic analyses and multi-objective optimization of a novel geothermal-solar multigeneration system. The system aims to produce hydrogen, freshwater, electricity, cooling load, and hot water and designed based on geothermal and solar energy. After modeling and thermodynamic and economic analysis, exergy destruction rate, exergy efficiency and, cost rate were calculated for each component of the system. The results showed that the highest amount of exergy destruction was related to parabolic trough collectors (PTCs) and absorption chillers. To select the geothermal fluid of the organic Rankine cycle (ORC), several different fluids... 

In the present study, a micro solar Combined Cooling, Heating and Power (CCHP) system based on Organic Rankine Cycle (ORC) is thermodynamically and exergoeconomically investigated. Adding a storage tank will lead to the sustainable supply of energy for summer and winter seasons. The model of conservation of energy, conservation of mass, and conservation of linear momentum are applied in order to energy analysis, while a model based on the first and the second laws of thermodynamics are used to exergy analysis. Determining the effective parameters of the system efficiency, including turbine input pressure, turbine inlet temperature, turbine output pressure, and evaporator temperature leads to... 

Anaerobic fermentation of crop straw/animal dug can be the most appropriate solution for biomass conversion into applicable renewable energy-based fuels. However, due to the imperfection matching between the biogas combustion process and energy conversion system, a painstakingly design procedure is required to devise high-efficient energy system for capturing biogas efficiently. For this aim, a new trigeneration system driven by biogas is devised for electricity, refrigeration, and potable freshwater generation. The devised system encompasses a gas turbine (GT) cycle, a new cooling/electricity cogeneration system based on organic Rankine cycle (ORC) and ejector cooling cycle (ECC), and a... 

In this study, the feasibility of producing power and hydrogen from the waste heat of different City Gate Stations (CGSs) is investigated to select the optimal working conditions. A thermodynamic model is developed for a proposed system combined of the CGS station, the Rankin cycle and the extended hydrogen production cycle. Initially, six CGS stations are simulated based on energy, exergy-economic and environmental analysis and then a comparative study is conducted between different stations. The results of numerical modeling show that the Mashhad-old station with 5315 kW and 31.062 ton/year has the highest amount of power and hydrogen production among other stations, respectively. It is... 

Three novel geothermal-based organic Rankine cycle (ORC) systems are proposed to enhance the efficiency and for waste heat recovery purpose. The proposed systems are modeled based on a basic ORC system (concept 1), an ORC system with an internal heat exchanger (concept 2), and a regenerative ORC system (concept 3). Accordingly, two thermoelectric generators (TEG) are introduced into the systems to exploit the waste heat of the system. The condenser is replaced with a TEG unit while the other TEG unit is used to recover the waste heat of the reinjected geothermal fluid. A comprehensive numerical investigation is conducted to compare the proposed systems from the thermodynamic and... 

Three novel geothermal-based organic Rankine cycle (ORC) systems are proposed to enhance the efficiency and for waste heat recovery purpose. The proposed systems are modeled based on a basic ORC system (concept 1), an ORC system with an internal heat exchanger (concept 2), and a regenerative ORC system (concept 3). Accordingly, two thermoelectric generators (TEG) are introduced into the systems to exploit the waste heat of the system. The condenser is replaced with a TEG unit while the other TEG unit is used to recover the waste heat of the reinjected geothermal fluid. A comprehensive numerical investigation is conducted to compare the proposed systems from the thermodynamic and... 

In this study, the performance of a system consisting of an organic Rankine cycle (ORC) for generating power and an electrolyzer for producing hydrogen with a zeotropic mixture as working fluid to recover waste heat in a geothermal flash-binary cycle is investigated from energy and exergy point of view. The study also investigates the effect of using zeotropic mixtures with different compositions as the ORC's working fluid rather than pure fluids. Using the particle swarm optimization (PSO) algorithm, the optimization is performed to maximize the power production of the entire system. The results show that using the combination of pentane with other pure fluids as working fluid led to... 

In this research, the design of a solar reverse osmosis desalination plant was investigated by integrating various components using TRNSYS and ROSA software. To this goal, a two-stage reverse osmosis system with 50% recovery in the city of Chabahar was modeled. The calculations were performed in three different case studies, i.e., a photovoltaic power plant, a solar collector power plant with Organic Rankine Cycles, and a photovoltaic thermal power plant with Organic Rankine Cycles, with the reverse osmosis desalination plant being a novel investigation. Water production and electrical energy generation of each case study were evaluated both on a daily and yearly bases. The simulation... 

Global warming is currently one of the biggest concerns worldwide; hence, addressing this issue is a trending topic among the research community. Escalating global warming through the wasted energy (30% of its input chemical energy) from internal combustion engines (ICEs) by exhaust emission is a major issue that should be considered. One way to reduce the waste of energy from ICEs is to recover the heat using a thermodynamic cycle. Using this method, not only does the engine power increase but also the fuel consumption decreases. Toward this end, and in this study, the organic Rankine cycle (ORC) and high-temperature Kalina cycle (HTKC), which have been previously used for other purposes,... 

In this study, the performance of a Photovoltaic Thermal-Organic Rankine Cycle (PVT-ORC) system combined with a Proton Exchange Membrane Electrolysis Cell (PEMEC) is investigated. A combined numerical/theoretical model of the system is developed and used to evaluate the effect of various system design parameters. In addition, the effects of using water, ethylene glycol, and a mixture of water and ethylene glycol (50/50) as the working fluid of the PVT system and R134a, R410a, and R407c as the working fluid of the ORC cycle on the performance of the PVT-ORC-PEMEC system are studied. Based on the results, R134a and water demonstrated the best performance as the working fluid of the ORC and PVT...