热力发电2025，Vol.54Issue(7)：43-53,11.DOI:10.19666/j.rlfd.202503042
超临界循环流化床锅炉变负荷特性模拟
Simulation of variable-load characteristics of a supercritical circulating fluidized bed boiler
摘要
Abstract
With the continuously increasing proportion of installed capacity from new energy sources,higher flexibility demands are imposed on coal-fired power generation units,including supercritical circulating fluidized bed(CFB)boilers.By taking a 350 MW supercritical CFB boiler as the research object,the computational particle fluid dynamics(CPFD)method was employed to simulate the furnace response characteristics under variable load conditions,focusing on parameters such as furnace temperature,near-wall particle concentration,and average heat flux density on heating surfaces.The effects of combustion and circulation interventions on the rate of load change were also explored.The results indicate that,during load ramp-up operation,the response rate of average heat flux density in low load range(30%～50%of the unit rated load)decreases by about 38%compared with that in high load range(above 50%of the rated load).Focusing only on the high load range,the heat flux density responds faster during load ramp-down,with the rate of change about 31%higher than that during ramp-up.Under varying load amplitudes,the particle suspension concentration and convective heat transfer intensity inside the furnace can respond rapidly,while temperature changes lag slightly,indicating that CFB boilers rely more on variations in the heat transfer coefficient for rapid thermal regulation.Through combustion interventions,such as substituting 40%of the original coal feedstock with fine coal particles sized several hundred microns,the change in furnace temperature can be effectively accelerated,with the response rate of average heat flux density during ramp-up in the high load range increasing by about 43%,and by nearly 16%in the low load range.Additionally,implementing circulation interventions,such as adding a certain amount of fine bed material during ramp-up,can rapidly increase the particle suspension concentration in a short time and thus effectively improve the response rate of the heat transfer coefficient on the heating surface.If hot fine material is further added(for example,through a hot circulating ash storage and return system),the response rate of the average heat flux density during ramp-up in the high load range can be improved by approximately 31%,and by about 13%in the low load range.The study elucidates the internal response mechanisms of CFB boilers under variable loading conditions,confirms the feasibility of improving load change rates through circulation and combustion interventions,and provides a reference for further tapping the flexibility potential of supercritical CFB boilers and improving their variable load capability.关键词
循环流化床锅炉/炉内过程/响应特性/燃烧干预/循环干预/数值模拟Key words
CFB boiler/in-furnace process/response characteristics/combustion intervention/circulation intervention/numerical investigation引用本文复制引用
刘梁,高凯旋,谢德清,何建乐,黄中,金燕,吕俊复,柯希玮..超临界循环流化床锅炉变负荷特性模拟[J].热力发电,2025,54(7):43-53,11.基金项目
"十四五"国家重点研发计划项目(2022YFB4100303) Key Project of the National Fourteen-Five-Year Research Program of China(2022YFB4100303) （2022YFB4100303）
