Network Based Simulation And Analysis Of Combustion Processes In Gas Turbines

Network based simulation of different combustors about flame temperatures and NOx or mean velocities is developed from simple models to complex models. During the process of simulation, different models for different combustion conditions are established and formulated, and reasonable results of simulation are got when they are compared to experiment data or other numerical simulation results.The establishment of network models is important to the solution of simulation problems. For the high-pressure jet-stirred reactor (HP-JSR) in which the reflected jet appears, the 2inlet-2PSR model is valid. The PSR and PSR-PSR models don't get reasonable results of simulation for the conditions. The partially stirred reactor also simulates the combustion processes which the single PSR is difficult to simulate and get the agreement with the experimental data. Based on the work, network models for complex combustors are established and the reacting processes are analyzed in detail by optimization from simplicity to complexity. According to the network models established, the numerical simulations are carried out by the CHEMKIN mode, and the reasonable results are got. It is found in the work that the models for the primary combustion zone are important. For the same condition, the different network models established can give different reactor temperatures. For the different conditions, the change of the gas flows and the difference of combustion ways can lead to different flow directions and flow ratios. This not only means that network models can change because of the change of conditions, but also shows that the flow distribution between the reactors can significantly change for it. The primary zones is indicative of these changes. It is found during the simulation that the primary zones are the ones of the highest temperatures and mean gas velocities. By the change of stoichiometric ratios in the primary zones, the fame temperatures can be controlled, and thus thermal NOx is controlled.The NOx formation in the HP-JSR is increased when the stoichiometric ratios are enhanced, and the reflected jets aren't helpful to the reduction of NOx from the results of simulation and experimental data. Thus it should try to avoid the appearance of the reflected jets and achieve lean combustion to low NOx.A few network models are explored in the paper, which can be used in the simple or complex combustor systems to simulate the combustion temperatures and NOx formation or mean velocities. The predictions will provide useful data for the research and design optimization of combustors with high combustion efficiency and low pollutant emission. The present work provides a basis for further developing PaSR model to simulate the NOx formation and flame temperature.