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Go to Editorial ManagerThe present work is aimed to reduce the annual electric energy consumption in a residential building in Basrah city through introducing a standardized rule for the annual electrical consumption for the cooling and heating purposes. This work will concentrate on all parameters which help to go toward the optimum use of thermally efficient house. The building energy analysis program e-Quest was used to simulate the annual energy consumption for a typical residential house built with different types of building materials. Transfer function cooling load calculation was used. The results showed that for the Base- House, the thermal transmission through the walls and roof constitutes more than half of the total peak cooling load. It was found that a house built with thermo-stone causes 5.9% reduction of the annual cooling energy consumption, and 12.4% in the annual heating energy consumption. However, insulating the Base- House causes a significant reduction in the air conditioning equipment capacity and consequently reduction in cooling energy consumption by 23%, and reduces the heating energy consumption by 42.8%. Finally this work presents a useful planning to developed building design which reduces the electrical energy consumption.
Thermal steam power plants represent the most important and dependable type for supplying the base load of electricity around the world. The thermos-economic analysis is an important tool for improving the performance of thermal steam power plants. In the present study, a thermo-economic analysis of a simple steam power plant for different boiler pressure was performed. The analysis comprises the energy, exergy, entropy, economics, and exergy-economic of a simple cycle steam power plant for different boiler pressure. The analysis was performed for a simple steam power plant with the constant output power of 10 MW and the boiler pressure is varied from 10 bar to 100 bar by a step of 10 bar. For each boiler pressure and constant output power, firstly, the fuel mass flow rate, steam flow rate, energy and exergy efficiency, and cost of electricity were calculated. Secondly, entropy generation, exergy destruction, and exergy efficiency for each component were calculated. Finally, exergy destruction economics for each component of the plant was performed. The results reveal that increasing the boiler pressure from (10 to 100 bar) for constant output power reduces the cost of electricity from (0.135 to 0.1025 $/kWh) due to a decrease in the fuel mass flow rate and an improvement in the thermal cycle and exergy efficiency. Also, when the boiler pressure increases, the exergy destruction for the pump increases, the exergy destruction for the boiler decreases, the exergy destruction for the turbine increases, and the exergy destruction for the condenser decrease.
The heat lost from gas turbine power plants with exhaust gases represents the most important source for lowering its thermal efficiency. Also, the gas turbine thermal efficiency affected significantly with the ambient surrounding temperature. Al-Najybia gas-turbine power plant in Basrah, Iraq is choosing as a case study. The power plant consists of four units with a capacity of 125 MW for each unit. In the present study, all the calculations are performed for one unit only. Firstly the thermal impact is studied in terms of energy analysis for Al-Najybia gas turbine power plant (GTPP) for different ambient temperature for twelve months. Also, the economic loss a companied the heat lost with exhaust gases for different ambient temperature are estimated. Secondly, the thermo-economic improvement from coupling the GTPP with a heat recovery system is studied. For gas-steam combined cycle, the performance and economic analysis are performed. The results show that, the output power and thermal efficiency are decreased by 0.97 MW and 0.0726% respectively for each unit temperature rise of the ambient temperature. For the combined gas-steam power plant the percentage increasing of the thermal efficiency is approximately 46.4%. The results indicate the combined cycle power plant (CCPP) is very important to increase electrical capacity. From the economic analysis, the economic gain due to using HRB is 75757 $ per month.