大湿度旋流扩散燃烧的变工况特性

采用湍流雷诺应力微分模型和层流小火焰模型，对湿空气透平(HAT)带旋流器的燃烧室内甲烷扩散燃烧过程进行了数值模拟．对比了在加湿[200g／kg(DA)]和不加湿情况下，不同入口条件时[(304kPa，430K)，(507kPa，510K)，(709kPa，565K)，(912kPa，612K)]的燃烧室内部温度、速度以及NO组分分布的情况，分析了不同入口条件及湿度对HAT循环燃烧室扩散燃烧特性的影响．研究表明，随着入口空气压力的提高，回流区减小，回流中心位置前移，燃烧区最高温度增加，NO浓度增大；随着入口湿度增大，回流区减小，回流中心位置前移，燃烧区最高温度明显下降，NO浓度明显下降．结果表明，加湿燃烧可以降低污染物的排放，有利于燃烧室轴线尺寸的缩小．

The Character of Swirl Diffusion Humid Air Combustion under Different Work Conditions

A combustion simulation adopting the Reynolds stress model and the Laminar Flamelet model was performed to determine the effect of humidity in the combustion air on temperature, velocity and NO distributions of methane/air diffusion combustion in a swirl combustor. The research work was conducted at different moisture levels (0,200 g/kg(DA)) under different inlet conditions((304 kPa, 430 K), (507 kPa, 510 K), (709 kPa, 565 K), (912 kPa, 612 K)). The effects of different work conditions and different humidity on the temperature field, the velocity field and the NO distribution were well predicted. The calculation results show: with the increase of inlet pressure, the dimension of the reversed-flow region is smaller, the center of the reversed-flow region goes forward, peak temperature increases, and NO formation increases; with the adding of moisture, the dimension of the reversed-flow region is smaller, the center of the reversed-flow region goes ahead, peak temperature drops greatly, NO formation is reduced enormously. It is suggested that humid air combustion is helpful to reduce the formation of pollution, and to shorten the axial length of combustor.