超超临界1000 MW二次再热机组塔式锅炉水动力特性及壁温分布规律

Thermal hydrodynamic characteristics and wall temperature distribution of an ultra-supercritical 1 000 MW unit double-reheat tower type boiler

超超临界二次再热锅炉运行参数高,其水冷壁服役环境更为苛刻,这对其水动力提出了更高的要求。本文以华能莱芜发电有限公司超超临界1 000 MW二次再热机组塔式锅炉为例,建立了水动力计算模型,通过现场数据采集和水动力计算相结合的方法,分析了BMCR、75%BMCR、50%BMCR、35%BMCR工况下的水动力特性及壁温分布规律。结果表明:下炉膛螺旋管圈水冷壁可以有效降低热负荷分布偏差带来的影响,明显减小流量分配偏差,抑制出口壁温偏差;上炉膛垂直管圈水冷壁虽然有一定的流量偏差,但由于超超临界二次再热机组塔式锅炉上炉膛内部有大量对流受热面,水冷壁的热负荷分布系数明显低于下炉膛,其壁温偏差仍然保持在合理的范围。

The working parameters of ultra-supercritical double-reheat boilers are high,making the working environment of water wall more harsh,which puts forward higher requirements for hydrodynamic power of the boiler.In this paper,the ultra-supercritical1000MW double-reheat tower type boiler in Huaneng Laiwu Power Generation Co.,Ltd.is taken as an example for the detailed thermal hydrodynamic research.Based on data from both field measurement and theoretical calculation,thermal hydrodynamic characteristics and wall temperature distributions are analyzed,under BMCR,75%BMCR,50%BMCR,35%BMCR condition.The results show that,the deviations of both mass flow rate and wall temperature decrease by using the spiral tube water wall in the lower furnace.Although there is somewhat deviation of mass flow rate in the vertical upward water wall,the wall temperature distribution is still in a reasonable region,due to a large scale of convective heat transfer area in the higher furnace.