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In the combined cooling, heating and power system, electricity is produced by prime mover. Recovered heat from the prime mover supplies heating and cooling demands. In this research, primary energy saving and carbon dioxide emission reduction are employed to evaluate the performances of cchp system compared with conventional system for residential buildings in Tehran. The combined cooling, heatig and power system follows Maximum electrical or thermal demand and Maximum rectangle electrical or thermal demand management. The results indicate that cchp system for residential five, eleven-storey buildings, in maximum rectangle electrical demand, maximum rectangle thermal and maximum electrical demand modes is the best strategy, if cooling demand is produced by absorption chiller and electric chiller. In the best strategy, primary energy saving and carbon dioxide emission reduction are 13% and 12%, respectively. If cooling demand is produced only by absorption chiller, primary energy saving and carbon dioxide emission reduction are decreased. In this case, maximum electrical and thermal demands are the worst strategies. In the worst case, energy consumption and carbon dioxide emission in cchp are increased 39% and 56% compared to the conventional system, respectively. Payback period in these strategies are calculated 5.5 and 7 years for 11 and 5 tories.

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Many researchers have been considered biomass utilization due to reduction of greenhouse gas effects and environmental impact recently. Achieving a system with the best performance for the application of this type of fuel with low calorific value is to be one of the topics of interest to researchers. This study focus on precise modeling of biomass gasification and design a trigeneration system to produce cooling, heating and electricity using this clean source of energy. In the process modeling of biomass gasification a realistic model includes tar content in syngas is developed. A parametric study of trigeneration system to find the objective functions trend and to achieve the best performance parameter is carried out. Results show that two objective functions in the reasonable range have conflict which emphasis to the multi-objective optimization. Also, with draw Pareto front curve, a suitable relation to estimate the trend of objective functions is derived.

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In this paper a combined cooling heating and power system for using heat losses in PEM fuel cell has been proposed, present system can use for residential application. This system consists of PEM fuel cell, Heat storage tank, absorption chiller, hydrogen tank, air compressor and pump. Heat generated in fuel cell has been absorbed by a working fluid and a part of heat has been given to absorption chiller and another part has been given to heat storage tank. Modeling of this system has been done from four energy, exergy, FESR and CDER perspective. Fuel cell of this CCHP system generates 38.63 kW electrical power and 39.17 kW heat power. Energy efficiency of fuel cell singly is 37.21% but when heat storage tank and absorption chiller has been used for recovering waste heat, energy efficiency reaches to 68%. Maximum irreversibility loss occurs in fuel cell which is calculated 47.21 kW and absorption chiller irreversibility has been calculated 5.94 kW. From viewpoint of FESR and CDER in comparison with conventional systems, FESR and CDER are 34% and 25% respectively. Also analyzes had been showed that with increasing fuel cell operating pressure energy and exergy efficiency increased and by increasing high pressure of chiller COP decreased

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The energy used to provide cooling and heating is a significant part of the energy consumption of an industrial complex. This paper aims to evaluate the performance of a trigeneration solar-powered system to supply the air conditioning system of an industrial complex energy requirement. The proposed design includes a double-effect lithium bromide water absorption chiller, a heat pump, and concentrating photovoltaic-thermal solar collectors (CPVT). Absorption chillers with nominal capacity and coefficient of performance of 100 TR and 1.3, respectively, and a heat pump with a capacity of 30 TR have been used to meet the cooling demands. The solar system consists of linear Fresnel solar concentrators and triple-junction solar cells. The analysis has been conducted for the complex located southwest of Tehran, Iran. Dynamic system simulation is performed using TRNSYS and EES software. To compare the performance of the proposed collector, photovoltaic-thermal collectors without concentrators (PVT) and Thermal collectors with concentrators (CT) with the same coating surface have been investigated. The energy delivered by the proposed collector is 64% and 28% higher, respectively than the PVT and the CT collectors. Compared to a structure without solar energy utilization unit, the proposed design reduces energy consumption by 62%. Employment of the heat pump in this method reduces energy consumption by 58% compared system without it. The proposed collector electrical energy production in a year is 101.10 MWh. The proposed system needs 264.07 MWh of backup heating a year to meet all the complex air conditioning needs.