气液双燃料燃气轮机燃烧室混合燃烧特性研究

A study of characteristics of gas-liquid dual fuel mixed combustion in gas turbine combustor

为解决双燃料燃气轮机燃烧室中的混合燃烧问题,对某原型燃油燃烧室进行了双燃料混合燃烧的数值模拟。通过模拟实验可知,在2种燃料混合燃烧的过程中,不断降低的液体燃料流量以及雾化压力导致的液体燃料雾化特性恶化以及气体燃料不断升高的喷射速度在径向上压缩液体燃料雾化空间是影响燃烧室混合燃烧性能的主要原因。在本文计算的混合燃烧过程中,燃烧室性能变化存在临界点,随着气体燃料占比增加,燃烧室火焰先缩短后延长,燃烧室出口温度分布系数(OTDF)先降低后升高,两者均在气体占比40%时达到最佳,而燃烧室液体燃料雾化质量、出口平均温度、效率均逐渐下降,且在气体燃料占比为70%时下降幅度最大,但在气体燃料占比100%时上升。

In order to solve the problem of mixed combustion in the combustion chamber of dual fuel gas turbine,a numerical simulation of dual fuel mixed combustion in the combustion chamber is carried out in this study,reaching a conclusion that in the process of mixed combustion,the main reasons that affect the mixed combustion performance of the combustor are the deterioration of the atomization characteristics of liquid fuel caused by the decreasing liquid fuel flow rate and atomization pressure,and the compression of the atomization space of liquid fuel in the radial direction caused by the increasing injection speed of gas fuel.In the mixed combustion process calculated in this paper,there’s a critical point in the combustor performance change.With the increase of the proportion of gas fuel,the combustion chamber flame first shortened and then extended,and the combustion chamber outlet temperature distribution factor(OTDF)first decreased and then increased.Both reached the best when the proportion of gas was 40%,while the atomization quality of liquid fuel in the combustion chamber,the average temperature at the outlet,and the efficiency decreased gradually,and the largest decline occurred when the proportion of gas fuel was 70%,but increased when the proportion of gas fuel was 100%.