【摘要】 针对1000 MW高效宽负荷率超超临界机组锅炉结构特点,将水冷壁划分为由流量回路、压力节点和连接管组成的流动网络系统。根据质量守恒方程、动量守恒方程、能量守恒方程,建立了超超临界垂直管圈锅炉水冷壁水动力计算模型。利用牛顿弦割法求解非线性模型得到了锅炉在BMCR负荷、75%THA负荷和30%THA负荷下的流量分配、炉膛出口汽温及水冷壁金属壁温分布情况。计算结果表明:各负荷下,壁温和鳍片温度在材料许可范围内,该采用垂直管圈的超超临界机组锅炉水冷壁在水动力方面安全可靠;30%THA负荷时水冷壁不会发生流动不稳定性。更多还原

【Abstract】 According to the structural character of an ultra-supercritical 1 000 MW unit boiler with high frequency and broad regulation load, the water system can be equivalent to a network system consisting of flow circuits, pressure grids and connecting tubes. On the basis of the mass conservation equation, momentum conservation equation and energy conservation equation, the hydrodynamic calculation model of water wall of the ultra-supercritical vertical tube coils boiler is established. By using the Newton’s chord cutting method, the nonlinear model is solved, and the mass flux distribution, outlet vapor temperatures and metal temperatures at BMCR, 75%THA and 30%THA load are obtained. The results show that, the temperature of the wall and fin is within the allowable range of materials and the water wall of the ultra-supercritical vertical tube coils boiler is safe and reliable in hydrodynamic aspect. The water wall will not flow instability at 30% THA load.更多还原