600MW超临界循环流化床锅炉水冷壁的选型及水动力研究

在超临界及亚临界压力范围内对不同尺寸的内螺纹管和光管的流动传热特性进行了实验研究,得到了偏离核态沸腾(DNB)和蒸干(DRYOUT)的发生规律、管子流动和传热的特性,建立了计算复杂流动网络系统回路流量及节点压力的数学模型,对非线性方程组采用迭代方法进行了求解,并对1台600 MW超临界循环流化床锅炉的水冷壁流量分配及壁温分布进行了计算.结果表明:在BMCR和在75%BMCR负荷下锅炉运行是安全可靠的.另外,笔者还研究了吸热偏差对流量分配及壁温分布的影响,结果表明流量与吸热量呈正响应特性.

Research on the Water Wall Design and Hydrodynamic Characteristics of a 600 MW Supercritical Pressure CFB Boiler

The heat transfer and flow characteristics of various ribbed and smooth tubes were experimentally investigated in the range of sub-and super-critical pressure.The DNB and Dryout boundary and heat transfer correlations were obtained from these experiments.The mathematical model for the circulation loop flow and pressure at junctions in a complex flow network system was established and an iteration method was used to solve the nonlinear equations.The water wall flow distribution and temperature profile of a 600MW supercritical pressure CFB boiler were calculated computationally,and the results show that safe operation in hydrodynamic at BMCR and 75%BMCR load can be expected.The effect of heat absorption on flow distribution and temperature profile was also investigated,it is demonstrated that a proper responsiveness between variation of medium flow and heat absorption can be achieved.