Low emission combustion chambers for gas turbine engines based on permeable volumetric matrixes

Abstract

One of the principal demands to modern gas turbine engines, which are widely used in systems of spread power supply and power reservation, is the decrease of emission of detrimental pollutants such as NOx and CO. Traditional combustion chambers for gas turbine engines are based on turbulent torch combustion of fuel and need complex structural schemes for the simultaneous decreasing of both NOx and CO emission. In this paper is proposed the principally new type of combustion chamber, primary aimed to obtaining the low emission of mentioned pollutants. Elaborated low emission combustors are based on laminar surface com-bustion of fuel-air mixtures in permeable for gas volumetric matrixes. Due to the intense recuperation of heat of reaction products to the surface of matrix and then to the fresh fuel-air mixture, the latter enters the flame front already preheated to significant temperature. Owing to this substance and the absence of radiation losses from the closed cavity of matrix, combustion limits of lean mixtures notably widen. The combustion of ultra lean mixtures and intensive heat transfer from flame front to matrix leads to low temperature of combustion, approximately 1200–1300 ^oC, at which the yield of NOx is extremely low. At that, the long time of location of hot combustion products in matrix cavity provide the high conversion of fuel with low yield of CO and other products of incomplete combustion. It lets to obtain in such combustion chambers extremely low yield of both NOx and CO. To provide the high specific power in combustor it was suggested the conceptual design of combustion chamber with developed matrix surface. Performed tests of laboratory model have shown that such chambers, especially operating at enhanced pressures, provide the decrease of such detrimental pollutants as NOx and CO to the level below 10 ppm, simultaneously providing energy and size parameters typical for combustion chambers of traditional type. At that significantly simplifies the design of combustion chamber, enhances its resource and stability of combustion.