Experimental Study On Combustion Performance Of Central-staged Combustor

The combustion performance of central-staged combustor is a hot issue in Aero engine research.There are many factors affecting its performance,such as the size and shape of the flame tube and the internal structure of the head cyclone.The structure of cyclone can be divided into several different factors.For example,the installation angle of blades at all levels and the rotation direction of blades at all levels.In this paper,the influence of the internal structure of the swirler in the combustor head,the blade rotation direction at all levels and the installation angle of the first stage blade on duty,on its combustion performance will be tested in a thermal state.At the same time,the effects of flame characteristics,oil-gas ratio,intake velocity and temperature on combustion performance(ignition characteristics and combustion efficiency)were tested at room temperature and preheating when working alone on duty.At the same time,this paper makes a numerical simulation analysis on the increase of the first-stage blade angle of the duty class and the influence of different rotation groups on the combustion performance.The head of the central-staged combustion chamber studied in this experiment is equipped with a staged cyclone,includes two stages of duty and a main stage.According to the requirement,six combination schemes are designed by changing the installation angle of the first stage blade and the rotation direction of all stage blades.Thermal tests are carried out separately,and the data obtained by thermocouple and flue gas analyzer are analyzed,and the optimal structure is finally obtained.In the numerical simulation,scheme G is added,the blade angle of the first stage on duty is increased to 70°,which is a total of seven schemes.The results show that the six different combination schemes have certain effects on the flow field,combustion efficiency and outlet temperature in the combustor.The optimal combination of rotation direction is that the first and second stage blades on duty are in the same direction,and the second stage blades are in the opposite direction with the main stage blades.The installation angle of the first stage blade of the swirler on duty is also an important factor affecting the combustion performance of the combustor.For the design scheme of this model,the optimal swirl angle combination of three-stage cyclone is from 45°to 60°for the first stage,45°for the second stage and 60°for the main combustion stage.This numerical simulation adds a comparison scheme G,so the conclusion is that the optimal swirl angle combination of the three-stage cyclone is 45°?60°for the first stage,45°for the second stage,and 60°for the main combustion stage.And the appropriate increase of the stage first stage blade mounting angle greater than 60°is more conducive to the improvement of combustion performance.