Numerical Study And Investigation Of The Annular Combustor Of Micro Gas Turbine

Due to large amount of biomass resource in China, the development of equipment which can utilize biomass resource efficiently and clean is very necessary. The CCHP system fueled with biogas is very suitable for the dispersive, small-scale utilization of biomass resource in China. And its industrialization prospect is quite promising and feasible. Besides, the project can solve the problem of electricity and heat supply in rural area and meanwhile reduce local environmental pollution, which is meaningful for building an energy-saving and eco-friendly society. The micro gas turbine generator set is the main power equipment of CCHP system. As an important part of a gas turbine, the combustor has great influence on the efficiency, stability and emission of the gas turbine. Intensive study on the internal flow and combustion process in the chamber is helpful to organize combustion process and optimize the construction.For reasons above, in this paper a 3D model of combustor using UG NX based on the real structure of Capstone C65 is set up. Numerical simulation of cold flow and lean-premixed combustion of natural gas are performed in ANSYS Fluent. The flow conditions and characteristics in a combustor are analyzed in detailed. The temperature distribution and NOx distribution are studied under the condition of starting condition and full load working condition, respectively.Second, the combustion of different kind of biogas are studied by numerical simulation. The mass flow rate of each kind of biogas is calculated. From the difference between the temperature field and NOx distribution in the same combustor when fueled with biomass and natural gas respectively, suggestions of improving the structure of combustor to make it more suitable for biogas combustion are made.At last, the application of catalytic combustion in gas turbine combustor is studied. Considering the active ingredient of catalyst is easy to be inactivated under high temperature, a method of filling the carrier with high heat conductivity metal or inorganic filler which can conduct the heat of reaction away in time and maintain a proper reaction temperature is brought up. A two-dimensional nine-speed(D2Q9) Lattice Boltzmann incompressible thermal model is introduced to carry out the numerical analysis of two-dimensional micro scale heat transfer in ceramic matrix composite. The influence of the shape and thermal conductivity ratio of the filler to the matrix are investigated.In conclusion,this paper simulated the multi-fuel combustion in micro gas turbine combustor, focusing on the influence of fuel composition as well as the heat value to the stability of combustion. Besides, the paper studied methods to improve the effective thermal conductivity of several catalyst carriers with different shape of filler, which provides a method of improving the efficiency, stability of a combustor.