Study On Combustion Characteristics For Raw And Relaxed Gas

The poly-generation technology coal-based is an integrated solution for current energy status such as "coal-rich, oil-poor, gas-less", low energy efficiency and air pollutions in our country. Furthermore, the status of coke production in large scale is considered in the poly-generation system by dual-gas resources. Except of chemical products, electricity is provided from poly-generation system. The system utilizes the remainded raw gas and relaxed gas from chemical process for power generation. When the operating conditions in chemical process change, the constituents, physicochemical properties of these gases are changed, which directly effects stable operation of the gas turbine. Therefore, it is very necessary for researching the combustion characteristics of raw gas and relaxed gas.On base of introducing for theories on gas combustion, physical models are constructed for the raw and relaxed gas combustion simulation in the following. Meanwhile, experimental system for testing gas ignition temperature is set up. In the thesis, combustor temperature distributions are discussed under different combustion conditions and models. The rules of gas ignition temperature affected by components are also researched. The gases used in the system are composed of H2, CO, CH4 and CO2 to replace the real gas. The temperatures received by adiabatic combustion simulation are close to theoretical combustion temperatures calculated by thermal equilibrium. As the combustor height increases, the combustor temperature rises first and then becomes invariant. The maximum is 2047K. When the quantity of heat inputted to combustor and the thermal boundary conditions are fixed, the combustion temperature drops as the methane volume content adding. If the methane content is also fixed, the combustion temperature decreases with hydrogen content increasing and the temperature rises with carbon monoxide adding. The combustor temperatures distribute asymmetrically owing to air flow velocities in the combustor. With the heat transfer coefficient increasing, combustor temperature drops, and the temperature gradients become steep at both radial and axial direction. When the excess air coefficient increases, the combustion temperature increases at the first but drops at last. The highest temperature appears when the excess air coefficient is between 0.9 and 1.0. The temperatures at radial direction distribute more asymmetrically when the burners shortens. The ignition temperature of decreases with the hydrogen contents increasing, and increases with the methane adding. Especially, the effects of carbon monoxide increase on the ignition temperature of gas are indeterminable. Ignition temperature keeps invariable, and is unrelated to the primary air when the thermal conditions of the system are fixed. The ignition temperatures for hydrogen, carbon monoxide and methane are separately 563℃,667℃and 790℃by the experiments.