Combustion Characteristics Study On Direct Flow-Type HiTAC Combustion Chamber

Emissions of combustion pollutants get extensive attention because of its more and more severe hazards to human health and the environment. HiTAC(High Temperature Air Combustion) has a technical advantage which ultra-low emission of NO_x and other pollutants can be gotten, therefore, how to apply the new technology in aviation gas turbine combustion chamber design is one of the key technology of new concept aviation gas turbine. In recent years, the combustion technology has been promoted and applied in gas turbine on the ground, and achieved good economic and environmental benefits.The core of reducing pollution emissions is to control the uniformity of combustion temperature field and to achieve low oxygen concentration. Currently the low pollution combustion chamber mainly has the types of grade fuel combustion, oil-poor premixed pre-evaporation combustion chamber, oil-poor direct injection combustion chamber and oil-rich combustion-quench-oil-poor combustion chamber. They have their own shortcomings, and it is too difficult for them to achieve ultra-low emission of NO_x less than 10ppm. So these technologies have difficulty to become the future mainstream technology of high-performance aviation gas turbine, their development prospects and promotion and application will be limited. scholars from various countries have shifted their attention to achieve efficient combustion and to solve the problem of ultra-low pollutant emissions by using high temperature air combustion technology(or high temperature air flameless combustion).This paper analyzes the current status of HiTAC combustion technology, the flameless combustion technology about aviation kerosene were analysed theoretically, a flameless combustion chamber model was designed and numerical simulation was carried out based on the early basic research of design and analysis-application of HiTAC aviation gas turbine combustor done by the research group. First, we carried the ejector and mixing principle of nozzle in new gas turbine combustor design, and AITFC(Air Injection Temperature Flameless Combustion) was proposed. In a variety of conditions, the jet ejector mixing efficiency, air flow distribution and oil-gas two-phase flow structure which required in flameless combustion and other characteristics of gas dynamics were studied numerically by CFD, this founds the base for design and analysis of new AITFC model combustion chamber. Second, we studied the combustion performance of AITFC combustion chamber numerically. The results show that the mixing hole diameter, the velocity of injected air and the fuel injection angle have important impact on flameless combustion characteristics. AITFC combustion chamber to achieve. Highly efficient and stable combustion can be achieved in AITFC combustion chamber; there is an uniform temperature distribution inside the combustion; the ultra-low emission of NO_x concentration which about 10ppm were achieved.