600MW超临界压力直流锅炉启动工况水动力稳定性分析

An Analysis on Hydrodynamic Stability in 600MW Supercritical Pressure Once Through Boiler During Start-up

文中介绍正在研制的国产600MW超临界变压运行直流锅炉水冷壁结构特点和启动过程。通过理论分析，得到了分析水冷壁水动力稳定性的准则方程式。根据锅炉的实际运行工祝，在高压汽水两相试验台上，进行了螺旋管圈水冷壁倾斜管中水动力不稳定性的试验研究。其参数为P＝2～4MPa，质量流速G＝600～1200kg/m2s，入口过冷度△tsub=10～120°C，热负荷0～650kw／m2，管径20×2mm，螺旋升角α＝14°。在上述参数范围内，研究了压力、质量流速、入口过冷度、热负荷及热负荷分布、进口和出口节流、可压缩容积对螺旋管圈水动力不稳定性的影响。由试验得出的计算公式，分析计算了锅炉水动力稳定性边界，在最小直流工祝时可能会出现压力降型脉动。

This paper introduces the waterwall features and start-up procedure of do-mestic 600MW supercritical variable pressure operating once through boiler under development.Tboriterion correlation of analysis on hydrodynamic stability in waterwall is established bytheoretical analysis.The experimental investigation on hydrodynamic stability in the inclinedtube of 'spiral type' waterwall was conducted in a high pressure steam-water two-phasetest rig according to actual cperating condition. Tbe experimental parameters are: P=2~4MPa, mass flux G=600~1200kg/m2s, inlet subeooling △t=10~120°C,heat fluxes 0~650kW/m2, tube diameter 20 × 2mm, helical angle α=14°. Within tbe above parameter ranges,the etfect of pressure, mass flux, inlet subeooling, beat flux and its distribution, inlet andoutlet throttle and compressible volume on the hydrodynamic instability in 'spiral type'waterwall were investigated. The correlation is estabished by experiment, and the hydrody-namic stability boundary in boiler is analyzed and Calculated. It shows that tbe pressuredrop type oscillation may occur during minimum load with once through operation.