Environmental pollution and emissions from greenhouse gases caused by fossil fuel use are a threat to sustainable development. With renewable energy sources, no polluting emissions are released into the atmosphere. Th...Environmental pollution and emissions from greenhouse gases caused by fossil fuel use are a threat to sustainable development. With renewable energy sources, no polluting emissions are released into the atmosphere. Therefore, using these sources on a large-scale is a key to reducing emissions and meeting the commitments established by Kyoto Protocol. Moreover, EU wants that the 20% of energy consumption is renewable in 2020. This study describes economic aspects, such as net present value and internal profitability rate, of the repowering process for the wind farms. Repowering can generate considerably more power with fewer facilities. This process was the result of a growing demand for renewable energies, facilitated by the great potential of wind energy in the north of Spain. The wind farms studied in this work were set up before 1998 and they had obsolete machinery with low power. There are strong indications that repowering is a profitable endeavour.展开更多
A 320 MW old steam power plant has been chosen for repowering in this paper. Considering the technical conditions and working life of the power plant, the full repowering method has been selected from different repowe...A 320 MW old steam power plant has been chosen for repowering in this paper. Considering the technical conditions and working life of the power plant, the full repowering method has been selected from different repowering methods. The power plant repower- ing has been analyzed for three different feed water flow rates： a flow rate equal to the flow rate at the condenser exit in the original plant when it works at nominal load, a flow rate at maximum load, and a flow rate when all the extractions are blocked. For each flow rates, two types of gas turbines have been examined： V94.2 and V94.3A. The effect of a duct burner has then been investigated in each of the above six cases. Steam is produced by a double- pressure heat recovery steam generator （HRSG） with reheat which obtains its required heat from the exhaust gases coming from the gas turbines. The results obtained from modeling and analyzing the energy-exergy of the original steam power plant and the repowered power plant indicate that the maximum efficiency of the repowered power plant is 52.04%. This maximum efficiency occurs when utilizing two V94.3A gas turbines without duct burner in the steam flow rate of the nominal load.展开更多
文摘Environmental pollution and emissions from greenhouse gases caused by fossil fuel use are a threat to sustainable development. With renewable energy sources, no polluting emissions are released into the atmosphere. Therefore, using these sources on a large-scale is a key to reducing emissions and meeting the commitments established by Kyoto Protocol. Moreover, EU wants that the 20% of energy consumption is renewable in 2020. This study describes economic aspects, such as net present value and internal profitability rate, of the repowering process for the wind farms. Repowering can generate considerably more power with fewer facilities. This process was the result of a growing demand for renewable energies, facilitated by the great potential of wind energy in the north of Spain. The wind farms studied in this work were set up before 1998 and they had obsolete machinery with low power. There are strong indications that repowering is a profitable endeavour.
文摘A 320 MW old steam power plant has been chosen for repowering in this paper. Considering the technical conditions and working life of the power plant, the full repowering method has been selected from different repowering methods. The power plant repower- ing has been analyzed for three different feed water flow rates： a flow rate equal to the flow rate at the condenser exit in the original plant when it works at nominal load, a flow rate at maximum load, and a flow rate when all the extractions are blocked. For each flow rates, two types of gas turbines have been examined： V94.2 and V94.3A. The effect of a duct burner has then been investigated in each of the above six cases. Steam is produced by a double- pressure heat recovery steam generator （HRSG） with reheat which obtains its required heat from the exhaust gases coming from the gas turbines. The results obtained from modeling and analyzing the energy-exergy of the original steam power plant and the repowered power plant indicate that the maximum efficiency of the repowered power plant is 52.04%. This maximum efficiency occurs when utilizing two V94.3A gas turbines without duct burner in the steam flow rate of the nominal load.
