The Influence of Operational and Structural Parameters on the Unevenness of the Temperature Field at the Outlet of the Gas Turbine Combustion Chamber

Abstract

Ensuring acceptable temperature field non-uniformity at the outlet of the combustion chamber is a very important requirement that determines the reliability and durability of the turbine. The formation of non-uniformity is determined by the nature of the interaction of the secondary air jets with the gas flow in the flame tube and depends on many factors, both structural and operational parameters. In this paper, we propose to evaluate the non-uniformity of the temperature fields at the outlet of the combustion chamber using a mixing coefficient that determines the quality of mixing jets of secondary air with a gas stream in the mixer. Based on the equation of turbulent diffusion during the flow of an annular jet into a limited space, an analytical dependence is obtained in the work that allows one to calculate the mixing process in the combustion chamber. The connection of the mixing process with the formation of temperature fields is established. Based on this, dependences are obtained for calculating the nonuniformity of temperature fields. Their satisfactory agreement with experimental data was shown. The found dependences allow one to analyze the influence of various parameters on the non-uniformity of temperature fields and accelerate the refinement of the combustion chamber by this parameter. The possibility of predicting the effect of various parameters on the unevenness of temperature fields is shown. The presence of the optimal value of the degree of opening of the mixer is confirmed, at which the minimum value of the unevenness of the temperature field at the outlet of the combustion chamber is achieved. Therefore, the analytical relationships found in the work allow optimizing the design of the mixer in the combustion chamber and the distribution of secondary air in it in order to reduce the unevenness of the temperature fields at the outlet of the combustion chamber.