Numerical Research On Mixing Characteristic Of R0110 Heavy Gas Turbine Combustor

Exit temperature quality is an important safety indicator of gas turbine combustor. However, because combustor is very complex, its design and experiment debugging are very empirical. The parameters can not be changed arbitrarily in the experiment due to the limitation of conditions. Therefore, strengthen theoretical study of exit temperature is very important.The debugging experiments of China-made heavy gas turbine R0110 dry low NOX (DLN) combustor showed that the exit temperature parameters did not match the designed values. After several experiments, it's not fundamentally improvement. Analysis shows that the main reasons are: first, the mixing design is unreasonable; second, the understanding of combustion in the DLN combustor and the features of the mixing are inadequate, the past experience does not apply absolutely and meet the experiment requirements.To solve the above problem, numerical simulation was adopted to study the mixing characteristic and its effects on the exit temperature field of the R0110 combustor on the basis of experiment. At the same time, the mainstream parameters distribution before mixing segment which can not be measured were speculated, which provide a reference for further improvement of the design and experiment of the combustor.At first, the parameters which have direct impacts on the exit temperature field were studied in this article. The parameters include mainstream gas temperature and speed distribution, mainstream and jet turbulence intensity, the residual rotation of the mainstream, the distribution of heat and flux between mainstream and jet. Research shows that the mainstream gas parameters were the decisive factors of the overall features of exit temperature field, mixing jet can changes the temperature distribution on a certain extent. This is consistent with the experiment results.The factors mentioned above which affect the temperature field were analyzed respectively. On the basis of this analysis, the combined effects of these factors were studied further in this work. It was found that the mainstream gas has relatively uniform temperature distribution which accorded with the DLN combustor premixed combustion characteristics. However, the mainstream velocity distribution is not entirely uniform because of radial staged combustion. Thus, two high-speed areas were formed in the central combustion area and ring combustion area respectively. The gas pipe of flame tube bend to inside, resulting in a deeper jet at the bottom, which lead to a stronger cooling effect. The combustor was designed counter-current, so that the flux of top mixing jet is more than that of the bottom jet. And this asymmetrical distribution result in the upward displacement of the exit center high-temperature area.Based on lots of simulation cases, the understanding of the effects of the mixing jet on the exit temperature field was improved. This provide an important foundation for further study of the mixing regulation, thus conclude a theory equation to optimize the combustor design and mixing structure. And the correlation will also provide a theoretical guidance for experiment.