Research On Design And Performance Of Steam Injection Dual Fuel Nozzle With Swirl

Chemically recuperated gas turbine(CRGT) can achieve the goal of high efficiency and low NOx emission. In CRGT cycle , high temperature flue gas discharged by the gas turbine to recover the partial heat, the fuel and the steam are used to generate the reforming gas under the action of the catalyst, then the reformed gas is fed into the combustion chamber to participate in the combustion process. In CRGT combustion chamber exist four kinds of different combustion modes: liquid fuel combustion, liquid fuel combustion and steam injection, liquid fuel and gas fuel combustion, only gas fuel combustion. In order to reduce the complexity of system structure and meet the different combustion modes, it is needed to design a dual fuel nozzle which can meet the four kinds of combustion forms at the same time.This paper takes the combustion chamber of industrial gas turbine as a based modle and designs the different structure of steam injection dual fuel nozzle with swirl.First ,combustion field of basic control equations and supplementary equation were described, then,different nozzle structure influence on combustion performance were analysised through numerical simulation method and geometric parameters of steam injection dual fuel nozzle with swirl on the combustion performance were investigated. On this basis, the gas injector of dual fuel nozzle design methods and ideas were establishmented, and the steam injection flameout limit boundary in combustion chamber with dual-fuel nozzle were given out. The main research contents are as follows:(1) According to the experience, four different kinds of structure of steam injection dual fuel nozzle with swirl were designed, liquid fuel combustion, liquid fuel combustion and steam injection, liquid fuel and gas fuel combustion, only gas fuel combustion and combustion performance was studied by numerical simulation method. The results show that the combustion performance of modle M1 which injection hole in aligned arrangement along the windward side of the swirl vane is the best.(2) The geometrical factors of the steam injection dual fuel nozzle with swirl were studied: nozzle installation position, the swirl blade vane angle, the gas fuel injection angle and gas fuel injection location influence on combustion performance.All these provid basis for dual fuel nozzle design.(3) This paper is proposed a dual fuel nozzle gas nozzle design method and design steps, based these one steam injection swirl dual fuel nozzle with swirl were designed, and the combustion performance and the steam injection flameout limit boundary were studied.The extinction boundary is 0.56kg/s.(4) Combustion performance of steam injection dual-fuel nozzle with swirl in the of the prototype counterflow combustion chamber were compared to its status in the combustion of fuel and combustion of gaseous fuel combustion performance status. The combustion efficiency is above 99%, and the influence of the variation of the reformed gas composition on the combustion performance is analyzed at the same time.