燃气蒸汽联合循环(natural gas combined cycle,NGCC)具有清洁、高效、部分变负荷能力强等特点,将NGCC机组与碳捕集系统耦合是实现碳减排的重要途径之一。以国际能源署(International Energy Agency,IEA)报告中的884 MW二拖一燃气蒸汽...燃气蒸汽联合循环(natural gas combined cycle,NGCC)具有清洁、高效、部分变负荷能力强等特点,将NGCC机组与碳捕集系统耦合是实现碳减排的重要途径之一。以国际能源署(International Energy Agency,IEA)报告中的884 MW二拖一燃气蒸汽联合循环机组为参考对象,利用Ebsilon软件对其进行建模验证。基于能量梯级利用原则,提出了4个不同的NGCC机组与碳捕集系统耦合方案,分别是抽汽回除氧器、抽汽换热回除氧器,抽汽回凝汽器以及增设小汽机加回热回除氧器。并进一步分析了4种不同耦合方案的热力性能,其能量惩罚分别为6.67%、6.59%、 6.81%和5.46%,得出方案4能有效降低能量惩罚。展开更多
The main objective of this investigation is to obtain an optimum value for the flue gas recirculation ratio in a 620 MW-Natural Gas Combined Cycle (NGCC) power plant with a 100% excess air in order to have a compositi...The main objective of this investigation is to obtain an optimum value for the flue gas recirculation ratio in a 620 MW-Natural Gas Combined Cycle (NGCC) power plant with a 100% excess air in order to have a composition of the exhaust gas suitable for an effective absorption by amine solutions. To reach this goal, the recirculated flue gas is added to the secondary air (dilution air) used for cooling the turbine. The originality of this work is that the optimum value of a Flue Gas Recirculation (FGR) ratio of 0.42 is obtained from the change of the slope related to the effects of flue gas recirculation ratio on the molar percentage of oxygen in the exhaust gas. Compared to the NGCC power plant without flue gas recirculation, the molar percentage of carbon dioxide in the flue gas increases from 5% to 9.2% and the molar percentage of oxygen decreases from 10.9% to 3.5%. Since energy efficiency is the key parameter of energy conversion systems, the impact of the flue gas recirculation on the different energy inputs and outputs and the overall efficiency of the power plant are also investigated. It is found the positive effects of the flue gas recirculation on the electricity produced by the steam turbine generator (STG) are more important than its cooling effects on the power output of the combustion turbine generator (CTG). The flue gas recirculation has no effects on the water pump of the steam cycle and the increase of energy consumed by the compressor of flue gas is compensated by the decrease of energy consumed by the compressor of fresh air. Based on the Low heating value (LHV) of the natural gas, the flue gas recirculation increases the overall efficiency of the power plant by 1.1% from 57.5% from to 58.2%.展开更多
文摘燃气蒸汽联合循环(natural gas combined cycle,NGCC)具有清洁、高效、部分变负荷能力强等特点,将NGCC机组与碳捕集系统耦合是实现碳减排的重要途径之一。以国际能源署(International Energy Agency,IEA)报告中的884 MW二拖一燃气蒸汽联合循环机组为参考对象,利用Ebsilon软件对其进行建模验证。基于能量梯级利用原则,提出了4个不同的NGCC机组与碳捕集系统耦合方案,分别是抽汽回除氧器、抽汽换热回除氧器,抽汽回凝汽器以及增设小汽机加回热回除氧器。并进一步分析了4种不同耦合方案的热力性能,其能量惩罚分别为6.67%、6.59%、 6.81%和5.46%,得出方案4能有效降低能量惩罚。
文摘The main objective of this investigation is to obtain an optimum value for the flue gas recirculation ratio in a 620 MW-Natural Gas Combined Cycle (NGCC) power plant with a 100% excess air in order to have a composition of the exhaust gas suitable for an effective absorption by amine solutions. To reach this goal, the recirculated flue gas is added to the secondary air (dilution air) used for cooling the turbine. The originality of this work is that the optimum value of a Flue Gas Recirculation (FGR) ratio of 0.42 is obtained from the change of the slope related to the effects of flue gas recirculation ratio on the molar percentage of oxygen in the exhaust gas. Compared to the NGCC power plant without flue gas recirculation, the molar percentage of carbon dioxide in the flue gas increases from 5% to 9.2% and the molar percentage of oxygen decreases from 10.9% to 3.5%. Since energy efficiency is the key parameter of energy conversion systems, the impact of the flue gas recirculation on the different energy inputs and outputs and the overall efficiency of the power plant are also investigated. It is found the positive effects of the flue gas recirculation on the electricity produced by the steam turbine generator (STG) are more important than its cooling effects on the power output of the combustion turbine generator (CTG). The flue gas recirculation has no effects on the water pump of the steam cycle and the increase of energy consumed by the compressor of flue gas is compensated by the decrease of energy consumed by the compressor of fresh air. Based on the Low heating value (LHV) of the natural gas, the flue gas recirculation increases the overall efficiency of the power plant by 1.1% from 57.5% from to 58.2%.
