[关键词]
[摘要]
以某1 000 MW超临界塔式锅炉水冷壁垂直管圈为研究对象,根据半侧绝热、半侧变热流和Y型三通的边界条件建立三维模型,进行数值模拟。模拟结果表明:在100%BMCR工况下,垂直管圈中超临界水入口温度为718.8 K,出口温度为729.8 K。内壁面的温度和超临界水的流速会受到截面积的影响,截面减小使得内壁面温度降低,流速增加;分析了传热系数对体积比热容和轴向流速的影响,发现体积比热容和传热系数变化趋势一致,轴向流动会极大影响传热;并最终拟合出新的符合垂直水冷壁工况的Nu准则式。
[Key word]
[Abstract]
A 1 000 MW supercritical tower boiler watercooled vertical pipe coil is taken as the research object for numerical simulation and a threedimensional model is established based on the boundary conditions of halfside insulation,halfside variable heat flow,and the Yshaped tube.Simulation results show that: under the 100% BMCR conditions,the inlet temperature of the supercritical water in the vertical pipe is 718.8 K and the outlet temperature is 729.8 K.The temperature of the inner wall surface and the flow velocity of the supercritical water are affected by the size of the crosssectional area,the small crosssectional area results in decrease in the inner wall surface temperature and increase in the flow velocity; After analyzing the relationship between the heat transfer coefficient and volume specific heat capacity and the axial flow velocity,It is found that the volume specific heat capacity and the heat transfer coefficient have a consistent trend,and axial flow will greatly affect heat transfer; Finally a new and fitting Nu criterion formula is determined for vertical watercooled wall.
[中图分类号]
TK221
[基金项目]