جستجوی مقالات مرتبط با کلیدواژه "multi-generation" در نشریات گروه "مکانیک"

In this paper, a new biomass multi-generation system based on micro-CCHP using an absorption refrigeration cycle and a desalination system, are presented to increase the performance of the basic cycle and to reduce the thermal wastes. A thermodynamic comprehensive modeling was done on the proposed system. also validation of subsystems and optimization of the system was done by genetic algorithm method with EES software. The results show that the dehumidifier has the highest exergy destruction among the other components of the system. The impact of the various system parameters such as; Evaprator1 temperature, Ammonia mass fraction, Absorber temperature, Difference temperature of heater, Generator1 pressure and heat source temperature is also done on the performance of the system. The parametric study show that by increasing the evaprator1 temperature, the energy efficiency of the system is increased. The maximum amount of energy and exergy efficiency of the system is 74.2% and 47.7%, respectively that occur at the 750-740 kelvin of heat source temperature. The energy and exergy efficiency of the base and MOOD case is 68.7% and 44.32%, 91.87% and 49.3%, respectively

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.

This paper presents a novel multi-generation system based on biogas fuel for simultaneous production of goods such as electricity, cooling, freshwater, and hydrogen using smart heat recovery of combustion gases. The performance of the proposed system is investigated in terms of the first and second laws of thermodynamics. Also, to acquire a comprehensive evaluation of operation costs, an exergoeconomic analysis has been performed. Furthermore, a comprehensive parametric study has been conducted to understand the behavior of the system performance parameters with the design parameters. In the following, to show the superiority of using a Stirling engine, the investigation of the present study is performed under two different scenarios. The proposed system could produce 986 kW, 137.5 kW, 8.39 m3/h, and 2.96 kg/h, net output electricity, cooling load, distilled water, and hydrogen while working with the Stirling engine. In this case, the energy and exergy efficiencies of the proposed system are obtained at 37.3% and 32.08%, which are improved by about 2.96% and 7.89%, respectively. In terms of cost metrics, the total unit cost of the products is about 0.1086$/kWh which has increased by 8.1% compared to the non-sterling engine mode.

Nowadays, one of the suitable technologies in terms of power generation and saving energy with high efficiency is using the multigeneration systems that renewable fuels are used as an alternative to fossil fuels. In the present study, a multigeneration system including biogas fired gas turbine, Organic Rankine Cycle (ORC), domestic water heater, Reverse Osmosis (RO) unit and Proton Exchange Membrane (PEM) electrolyzer. The proposed multigeneration system is assessed from energy and exergy viewpoints. After that, a comprehensive parametric study is carried out to show the effects of some key parameters (including pressure ratio of compressor, condenser pressure, evaporator temperature, preheater temperature and inlet temperature of gas turbine) on main performance criteria of the multigeneration system. Finally, the multi generation system is optimized from thermal efficiency point of view. The optimization results indicate that the thermal efficiency has optimum values for evaporator temperature and pressure ratio of compressor. Also, results show that the values of generated power, produced fresh water, thermal efficiency, exergy efficiency, produced hydrogen and total exergy destruction are calculated as 1192 kW, 5.584 kg/s, 55.74%, 30.56%, 1.455 kg/hr and 2827 kW, respectively.

The usage of multi-generation systems is quickly developing in the last decade. The current study develops a new geothermal based integrated system, double flash, organic Rankine cycle (ORC), proton membrane electrolyzer (PEM), reverse osmosis (RO) unit and domestic heat water. The configuration is designed to produce four outputs namely, power, heating, desalination water and hydrogen. The proposed multi generation system is evaluated from thermodynamic and exergy point of view. A comprehensive parametric study is done as well and then, the multi generation system is optimized for three viewpoints (net output power, thermal efficiency and exergy efficiency). The results show that the net output power, thermal and exergy efficiencies have optimum values in regard to two separator pressures. Also, optimization results from net output power viewpoint show that, the power generation, desalination water, thermal efficiency, exergy efficiency, hydrogen production and heating were obtained as 5091 kW, 41.75 kg/s, 15/58%, 43.44%, 2.83 kg/hr and 350.6 kW, respectively.

In this paper, a novel multi-generation system based on gas turbine-modular helium reactor cycle is presented. Integrated system consists of a Gas turbine-modular helium reactor cycle as a base cycle and from the combination of subsystems, hydrogen production, absorption refrigeration cycle, and desalination system. Thermodynamic comprehensive modeling (energy and exergy) was done on the suggested system. The effect of various system parameters, such as turbine inlet temperature, compressor pressure ratio, carbon dioxide to methane molar ratio, vapor generator temperature, and mass flow rate of the desalination system have been evaluated on the overall performance of the system. Also, optimization of the overall system using single and multi-objective optimization method has been investigated in terms of energy and exergy compared to the base case. The results showed that the maximum net power output and the energy efficiency and exergy of the overall system in compressor pressure ratio between 2.3-2.45 were 275 MW, 72.05%, and 49.35%, respectively, and with increasing turbine inlet temperature, heat production rate and energy and exergy efficiencies of overall system increases and the cooling production rate and freshwater decreases. In addition, the optimal point of the mass flow ratio of the desalination system for the energy and exergy efficiencies of overall system is 2.857. According to the results obtained in the multi-objective optimization method, the energy and exergy efficiencies of overall system were 74.41% and 50.21%, respectively, and exergy destruction has been reduced to 0.74% compared to base case.