Solar field transfer heat of solar radiation to the heat transfer fluid. Appropriate size of solar field is one of the most important parameters in levelized cost of solar electricity. In this paper optimum solar field size in an integrated solar combined cycle is determined. Furthermore, an algorithm is presented for the simulation of parabolic trough solar collector performance. Four solar fields by different size but same power block are considered. Thermal performance of each field in terms of nominal and partial load conditions is studied. Solar field and combined cycle are simulated by coding in EES software. According to The hourly meteorological data, electricity generated for a year is calculated. Levelized cost of solar electricity for each field size is calculated and optimum size of the field is selected. According to the economic analysis, the optimum solar field size in an integrated solar combined cycle is depended to location of plant, HRSG power demand, and the constraints of the power block and solar field.

In this paper, a thermodynamic modeling and a comprehensive performance analysis of a real integrated solar combined cycle (ISCC) power plant are performed. The performance of the plant cycle is assessed in an off-design condition and in two operation modes of power-boosting and of fuel-saving. Such an approach has not been considered for an ISCC plant in previous studies. Yazd ISCC, as a case study, consists of parabolic collectors which are connected to a combined cycle section. The presented simulation results cover different times of the day and the twelve months of the year. According to these results, in the power-boosting mode, the steam production of the fossil section is reduced by 12 kg/s from 6: 00 AM to 3: 00 PM on the design day while the solar steam increases by 36 kg/s. By stabilizing the oil temperature on 392°, C, the control philosophy of the starting of steam production in the solar field is also discussed. In the fuel-saving mode, if the solar field is in service, the fuel consumption of the auxiliary burners is reduced by 28, 000 kg on the design day. The results of this paper indicate that the power output of ISCCs is more stable than the conventional combined cycles on the hot days of the year.

An integrated solar combined cycle (ISCC) is analyzed at "offdesign" operating conditions. Using the principles of thermodynamics heat and mass transfer a computer code is developed in FORTRAN programming language to simulate the system’ s hourly performance under steady state conditions. Three scenarios are considered for the study. In the first one, only the combined cycle (CC) is studied. In the second scenario, two solar heat exchangers are added to the system (ISCC) to produce some extra steam fed to the steam turbine for more power production. In the third one, as that of the ISCC scenario, a supplementary firing is used instead of solar heat exchangers to produce the same power. The main performance parameters are calculated for the hourly variation of solar direct normal irradiation intensity (DNI) and ambient air temperature for analyzing environmental benefits of using solar energy instead of supplementary firing. Results show that the contribution of solar energy in the annual produced power by the ISCC scenario is 75. 14 GWh, which is 2. 1% of the whole. In addition, it is found that using solar energy leads to an annual reduction of 36. 13 Kton in the produced CO2 and an annual fuel saving of 3. 76 ton.

In this paper, exergy analysis is used to evaluate the performance of a combined cycle: organic Rankine cycle (ORC) and absorption cooling system (ACS) using LiBr–H2O, powered by a solar field with linear concentrators.The goal of this work is to design the cogeneration system able to supply electricity and ambient cooling of an academic building and to find solutions to improve the performance of the global system. Solar ACS is combined with the ORC system-its coefficient of performance depends on the inlet temperature of the generator which is imposed by the outlet of the ORC. Exergetic efficiency and exergy destruction ratio are calculated for the whole system according to the second law of thermodynamics. Exergy analysis of each sub-system leads to the choice of the optimum physical parameters for minimum local exergy destruction ratios. In this way, a different connection of the heat exchangers is proposed in order to assure a maximum heat recovery.

The integrated gasification combined cycle power plant using hydrocarbon fuels produces cleaner and more efficient electricity through gasification, compared to direct fuel burning. In this paper, the power plant has been simulated and validated by Thermoflow software according power plant characteristics. The assumptions are applied and exergy analysis is done using EES software. The results of energy and power consumption analysis of the obtained components and exergy analysis are applied to find the values and locations of system irreversibility. The net output of the cycle and thermal efficiency are 234. 89 MW and 30. 69% respectively. The exergy efficiency of the power plant is 45. 57%. Maximum amount of irreversibility is from the gasifire, gas cleanup system, and HRSG, respectively 216. 600, 210. 607 and 113. 653 MW. Finally, the cycle is analyzed parametrically and the effects of the gas temperature change and pressure of the condenser on the efficiency and final power of the power plant have investigated.

Using renewable energy sources as a solution for country⠀™s stable growth needs distinct look in topics of energy production. Agriculture industry is a general industry and it is an energy consumer that can be considered as a topic in this field. Existing a based refrigerator in farm and garden makes optimized harvesting and because it is easy to use sun radiation at these places, it can be used as a source of energy for providing refrigerator⠀™s energy. One of important needs in refrigerator, is producing continues and stable effect of refrigeration in operator while radiation release is intermittent and variable. By presentation of synthetic cycle of absorbing refrigeration, liquid refrigerant can be stored during radiation, so it can be used in other situations and as a result continues and stable effect of refrigeration can be produced. Considering collector⠀™s parabolic shape optimized temperature, 119. 6 ° C in generator is available. Optimized temperature of condenser, absorber and operator, in order equals 40, 43. 7 and-3. 2 ° C. By selecting 14bars for pressure in generator and condenser and 2bar pressure for operator and absorber, maximum coefficient of operation is 0. 178 and rate of heat transfer in generator, condenser, absorber and operator is achieved 19. 76, 7. 51, 15. 77 and 3. 51 Kw in order.

Combined heat and power systems are used for renewable energies and reducing fossil fuels. This work, investigated energy efficiency, exergy, and exergy economic a Brayton cycle and refrigeration cycle with an ejector that used solar energy as a heat source. Inlet pressure turbine, outlet pressure turbine, inlet temperature turbine, and temperature of the evaporator are variable parameters, when one of the parameters changes, the other parameters are kept constant so that the thermodynamic analysis focuses on important parameters. Results showed that inlet pressure of initial flow in ejector and outlet velocity of flow on ejector are increased with increasing outlet pressure of turbine. The storage tank had the most exergy destruction rate among all components for the high-temperature difference that it’s almost 29% from all of the exergy destruction rates. Also, the highest cost per unit of power is related to the combined heat and power cycle that it’s about 53% of the total cost.

One of the latest technologies in the field of small thermal power plants is the combination of the solar Brayton cycle and organic Rankine cycle. These power plants have advantages such as preserving natural resources, reducing emissions, reducing fuel costs, and increasing efficiency. Consequently, these power plants contribute to sustainable development goals by producing clean energy. In this study, the thermodynamic analysis of a small power plant equipped with a Solar Brayton Cycle (SBC) combined with an Organic Rankine Cycle (ORC) is performed with the THERMOFLEX code. In such a power plant, solar energy is used to preheat the air entering the combustion chamber in the Brayton cycle. Also, the heat in the exhaust air from the Brayton cycle turbine is used to drive the organic Rankine cycle (ORC). The results from thermodynamic simulations showed that the expansion power of the gas turbine in the Brayton cycle and the steam turbine in the ORC cycle are 98.91 kW and 8.11 kW, respectively. Also, the electrical power produced by the generators connected to these turbines is 37.82 kW and 7.24 kW respectively. The total electrical efficiency of the power plant was calculated as 24.25%. This efficiency value was obtained in the condition that the solar input power is 64.67 kW and the combustion chamber heating power is 116.7 kW. In Brayton cycle modeling, the compressor pressure ratio was considered to be 4.3. By increasing the compressor pressure ratio up to 7.6, the efficiency of the power plant increased, and with a further increase in the pressure ratio, the efficiency had a decreasing trend.

In this research at frist the cogeneration system comprise the cascade steam Rankine cycle, absorption cycle and vapor compression cycle with parabolic trough solar collector as heat source are simulated from energy, exergy, economic and exergoeconomic point of view. The simulation is in this manner: at first the mass, energy and exergy conservation equation are written and the with cost balance equation in different component of system, investment cost and exergy destruction cost rate are calculated. The result in basic input mode shows that total work output, total exergy destruction and net exergy efficiency are 35.21 KW, 356.8 KW and 12.5 % respectively. The exergoeconomic results show that total cost rate is 56.86 $/hr and total exergoeconomic factor is 45.02 % that shows a good balance between initial and exergy destruction cost rates. also solar collector and steam turbine should be further considered from the exergoeconomic viewpoint since these components have the highest value of cost rate. At the end, a parametric analysis are done in order to the investigation of the effect of change steam evaporator temperature, pinch point temperature different, steam condenser temperature and generator temperature on system performance from energy, exergy and exergoeconomic point of view.

Integrated Gasification Combined Cycle power plants generate electricity by utilizing the syngas obtained from the carbonaceous materials via gasification. These systems commonly use coal fuel, however, biomass fuels like bagasse could be a more environmentally friendly option. This study was aimed at analyzing the effects of varying operating parameters (such as temperature, pressure, O2/fuel, and water/fuel ratios), and fuel feedstocks (i. e., coal, bagasse, and coal-bagasse co-firing) on the syngas composition. Based on the data obtained from a commercial power plant, an equilibrium model was developed and validated using the Aspen Plus® software. Sensitivity analysis was carried out by varying the considered operating parameters and selected fuel feedstocks. The results of this study have manifested that low temperatures, low O2/fuel ratio, and high water/fuel ratio produce syngas with a comparatively higher H2/CO ratio. The highest H2/CO ratios of 1. 16, 0. 99, and 0. 84, were obtained for bagasse, co-firing, and coal, respectively at operating parameters of 1200°C temperature, 0. 5 O2/fuel, and 0. 6 water/fuel ratios. Furthermore, bagasse and co-firing of coal-bagasse feedstocks could provide a better quality of syngas as compared to that of coal feedstock. The results of this study would also help to operate the Integrated Gasification Combined Cycle plants at optimum performance by utilizing different fuels and by appropriately adjusting the operating parameters.