燃烧器流动换热性能数值模拟

针对燃烧器内壳体壁面在高温燃气作用下产生变形、裂纹、皱曲和局部过热等故障,该文采用FLUENT软件对燃烧器的流动换热特性进行了数值计算,建立了燃烧器流动换热的物理模型,分析了高温燃气的压力、温度及速度分布、燃烧器内壳体内外壁面的温度分布、冷却水侧的温度分布和压力损失,旨在为燃烧器研发、设计及优化提供理论依据。数值计算结果表明,燃烧器喷管流通面积的减小使燃气的流速急剧增大,对燃烧器球形底部形成强烈冲击,导致燃烧器底部传热恶化,冷却效果不好,出现局部高温;冷却通道内冷却水最高温度小于冷却水压力对应的饱和水温度,冷却水不会发生沸腾;冷却水通道的沿程压降主要损失在螺旋通道内。

Numerical Simulation on Flow and Heat Transfer Characteristics of Combustor

Addressing the faults on the hull walt of a combustor, such as deformation, crack, wrinkle and local over-heat under high-temperature gas, three-dimensional numerical simulations of flow and heat-transfer eharaeteristies of the eombustor are conducted via the standard k-ε model with standard wall function and DO radiation model. Results show that heat transfer performance of the half-ball bottom worsens because the reduction of the flow area in the combustor nozzles makes the velocity of gas flow sharply inerease, and temperature is higher at some parts of the bottom. The highest temperature of cooling water in the cooling passage is lower than the saturation temperature corresponding to the cooling water pressure, the water-side pressure drop of the eombustor depends primarily on the shape of the spiral passage, and the total pressure drop in the cooling passage is smaller than the allowable maximum value.