Numerical Simulation Of Oxygen Enriched Combustion Characteristics Of Natural Gas In Pressure Environment

Energy is an important prerequisite for the protection of national development,but the environmental problems caused by burning fossil fuels can not be ignored.The use of environmentally friendly energy instead of coal power generation has become a viable way.Distributed energy system improve the utilization of energy,gains increasing attention.Oxygen-enriched combustion can improve the combustion efficiency and save the amount of fuel,but it will lead to the increase of NO_x emission.It is of practical significance to carry out research on high-pressure oxygen-enriched combustion in today’s increasingly serious environmental pollution.This paper is based on the high pressure reheat gas-steam combined cycle,the existing high-pressure combustion test equipment on the basis of high-pressure oxygen-rich combustion simulation study to study the high-pressure case of oxygen-rich combustion characteristics.The main contents are as follows:First of all,according to the existing high-pressure combustion test bench in the pre-processing software Gambit in the establishment of numerical models and meshing,and verify its rationality.Then,the simulation of oxygen-enriched combustion with 21% ～ 50% oxygen-rich concentration under high pressure was carried out.And the temperature field distribution,flame morphology,central axial temperature variation,combustion chamber outlet temperature,NO_x formation law and oxygen concentration were investigated.It is found that increasing the oxygen concentration alone will increase the flame temperature,shorten the flame height.However,the increase of the flame temperature leads to a large increase in the generation of thermal NO_x,and the high temperature resistance of the outer wall of the combustion chamber is required,and it is necessary to enhance the cooling measures.Finally,the oxygen-enriched combustion characteristics in the range of 0.1 ～ 12 MPa were studied.The results show that the combustion temperature increases first with the increase of pressure,and begins to decrease gently after 8MPa,and the NO_x generation and temperature have similar changes.To improve energy efficiency and to control the emission of pollutants in the combustion process is the most important task in China’s energy field.The combustion technology in this paper reflects the high integration of the above two aspects.The research results can be used to research and popularize high efficiency and low pollution Oxygen combustion technology and the design of new burner to provide experimental basis and theoretical guidance.