The Optimization Of Low Calorific Value Operating Technology By M701SDA BFG Firing Gas Turbine

The Lower Heating Value (LHV) gas turbine combined cycle power generation is the high efficient and clean power generation technology, and it can make full use of secondary energy sources such as blast furnace gas (BFG) and coke oven gas (COG). BFG usually mixes with COG, which has a higher calorific value, in order to improve its heating value for the ignition and stable-combustion. Because of instability of domestic steel mills’COG supply, calorific value of the fuel gas to gas turbine cannot be guaranteed, and easily leads to instability and fluctuation of, combustion, and even causes unit trip. The purpose of this work is to investigate operation and combustion stability of gas turbine under the LHV conditions, and further to expand the calorific value range of gas turbine fuel in order to extend the application of lower calorie gas turbine.The theoretical analysis of LHV combustion are made at first. Mathematical models are built to verify the influence factors of diffusion combustion stability under the LHV operation conditions, the mechanism of thermoacoustic oscillation combustor and combustion vibration conditions. The flow characteristics of gas turbine and its security are discussed under the conditions of LHV.Experiments under lower calorie value conditions were made to verify the performances of M701SDA BFG firing gas turbine. Combustion tuning, load swing, fast runback and load rejection were included. The results show that firing the lower calorie BFG, M701SDA gas turbine can run normally without the updating of combustors and burners. Combustion fluctuation, BPT spread and other parameters are normal while running at LHV.Through the theoretical derivations and experimental analysis, the gas turbine operating calorie was changed from 4400kJ/Nm3 to a range of 3200-4400 kJ/Nm3 successfully. It means M701SDA can fire 100% BFG to generate electricity and this will greatly improve the fuel flexibility, reliability and economic efficiency of M701SDA combined cycle power plant.