IGCC电站燃气轮机启动燃料的替换研究

当整体煤气化联合循环(integratedgasification combined cycle,IGCC)电站低热值合成气燃气轮机的启动燃料为柴油时,启动成本高,污染物难以控制。为了解决该问题,一个较适用的方法是将燃气轮机的启动燃料由柴油替换为天然气。但由于2种燃料的燃烧特性的不同,需要对燃机在两种不同燃料下的动态特性进行深入的研究,从而提出相应的改造和运行策略。基于天津IGCC低热值燃气轮机的结构及实际运行数据,建立燃气轮机热力学计算模型,对比分析了燃气轮机启动过程中,柴油量、天然气量随燃气轮机负荷的变化情况;其次计算了燃烧器燃烧天然气时的火焰稳定速度范围和优化燃烧器当量直径的范围;并对该燃气轮机燃烧室内的燃烧过程进行了数值模拟研究。最后提出了燃烧器的改造方案和运行策略,在尽量小的范围内进行改造来实现对柴油的替代而且保证燃机的稳定、安全和清洁启动。

Study of the Substitute of Startup Fuel for An IGCC Power Plant Gas Turbine

When diesel is use as the starting fuel for low heating value syngas gas turbine of an IGCC power station,the starting cost is high and the pollutants are difficult to control.To solve this problem,a more suitable method is to replace diesel with natural gas as the starting fuel.However,due to the different combustion characteristics,it is necessary to conduct an in-depth study on the dynamic characteristics of the gas turbine under two different fuels,and then to propose corresponding modification and operation strategies.Based on the structure and actual operation data of Tianjin IGCC low heating value gas turbine,the thermodynamic calculation model of gas turbine was established.The flow rate variations between diesel and natural gas at different load during gas turbine startup were compared and analyzed.Secondly,the flame stability of the burner burning natural gas was calculated and the operating range was given.The dynamic simulation of the combustion process of the gas turbine was carried out.Finally,the reforming scheme and operation strategy of the burner were proposed,and the modification was carried out in the smallest possible range to realize the substitution of diesel and ensure the stability,safety and clean start of the gas turbine.