起动机驱动过程中 微型燃气轮机燃烧室变工况燃烧特性

In order to investigate the trends of off-design combustion performance under starter-driven process for a micro-gas turbine (MGT) combustor, the overall performance experiment of the MGT prototype was employed. The MGT prototype was designed on single shaft mode and includes a single stage centrifugal compressor, a lean premixed swirling combustor, a single stage centripetal turbine and an air-cooling frequency conversion starter/generator. The results indicate that: due to the relatively low temperature of the flue gas, NO formation is approximately zero. As the starter speed (n) increases, the trend of CO₂ mass concentration is almost consistent with the combustion efficiency (η) trend, but opposite to that of CO mass concentration. The mean outlet temperature is mainly affected by inlet air temperature (T₃), η and equivalence ratio, thus its fluctuation trend is different from these three under the starter-driven process. The total pressure recover factor of the combustor has a drop with the rising n due to the increasing thermal resistance and flow losses. The chemical reaction process of fuel can not only have an influence on the compressor back pressure, which leads to the rising T₃ and inlet total pressure of the combustor, but also cause the obvious fluctuations in inlet and outlet total pressures of the combustor. Based on the operation conditions and non-dimensional structure sizes of the combustor in the current research, the flow resistance coefficient of 35 is satisfied for the design requirement of the combustor.