Research On Formatting Rule Of NOx From Gas Pulse Combustion

Pulsating combustion is a new technique that has the potential of high efficiency and low emission of pollutants. Because pulsating combustion is a complicated process, it is difficult to do further research theoretically, which limits its development and application in industry.Aimed at the problem, the process of pulsating combustion was studied based on its cycle characteristic with wave theory, and then to summarize the requirements of time and space to drive the pulsating combustion. According to Rayleigh Criteria and the theory above mentioned, a Helmholtz pulse combustor was designed. With the help of MRU Gas Analyzer, experiments were carried out to study the formation rules of NOx production. Conclusions as follows were drawn from the experimental results. To drive pulsating combustion, combustion intensity is claimed besides requirements of time and space. When the fuel coefficient is about 1.0, measurement of NOx concentrate is 30-60ppm for different tail pipe on the condition of pulsating combustion, which is lower than steady combustion. The NOx concentrate increases as the fuel coefficient increases from 0.68 to 1.0. Only at the fuel coefficient is near 1.0, do the NOx concentrations increase with an increase in pulsating frequency and no systematic trend with pulsating frequency at lower fuel coefficient. The process of pulsating combustion is simulated based on the different pressure between combustion chamber to fulfill the supply and break of fuel gas, and the roles of NOx emission is analyzed. It is periodical of NOx emission, which is same to other characteristics of pulsating combustion. The NOx concentration is affected by the temperature of combustion chamber as steady combustion. But the high temperature retains for a short time because of the pulsating combustion, and the vortex makes it instantaneous for the combustion reaction, which delays the NOx reaction and decreases NOx emission. Finally, NOx emission affected by other characteristics in flow field was discussed.