为提高电站锅炉受热面的运行安全,通过优化吹灰器控制回路冗余触点,增加触点故障报警和监视,同时在分散控制系统(DCS)增加急退、退超时报警和智能检漏识别等功能,可有效预防吹灰器在运行过程中潜在的风险,防止吹灰器未退到位,内漏损坏锅炉受热面.某660 MW机组通过优化后,运行过程中未发生内漏情况,降低运行和检修人员维护工作强度的同时,保证机组运行安全,提高机组运行经济性.

In order to find the reason for tube-bursting of 660MW supercritical boiler final superheater, the macro-morphology, chemical composition, microstructure and mechanical properties of the tube were analyzed. The results show that the contents of elements of final superheater pipe meet the requirements of the standards, and the tensile and yield strength are qualified. The burst mouth of the burst tube is wide and its microstructure becomes deteriorate, which shows typical features of short-term serious over-temperature tube-bursting. On this basis, the measures, such as controling the flue start-up gas temperature, strengthening the wall temperature monitoring, improving the quality of water supply and controling temperature change rate and others were put forward, and the safe and stable operation of the boiler was effectively ensured.

为研究钢结构小机间冷塔的阻力特性,以某电厂660 MW直接空冷机组小机间冷塔为研究对象,运用流体力学方程建立计算模型,借助ICEM-CFD及Meshing软件完成网格划分,利用Fluent软件计算了模型各处的流场特性,使用ANSYS软件计算了小机间冷塔各部位的阻力系数.结果表明,钢制空冷塔喉部区域负压最大,空气流速最大;X柱处局部阻力系数小于筒身处,折弯处的局部阻力系数最大;塔身各处局部阻力系数随雷诺数增大变化较小.

目前国内循环流化床(CFB)锅炉大部分采用床上、床下燃烧器联合启动方式,仅配置床上高功率重油燃烧器的CFB锅炉由于参数控制难度大,启动过程极易结焦.对此,通过对国外某电厂锅炉重油启动燃烧器启动过程的分析,提出了提高给水温度、减小总风量、控制主蒸汽压力等启动方法,以及对启动过程中一、二次风、床压及燃烧器、锅炉升温速率、投煤参数等的控制要求,可为今后同类型CFB锅炉启动提供借鉴.

Coking occurs more frequently in the start-up process of circulating fluidized bed boiler( CFBB) with heavy oil ignition over bed. Based on a coking accident during the start-up process of a new CFBB,this paper analyzed the coking reasons that were improper wind-oil ratio,design defect of oil gun shield,incorrect positioning of oil gun,mixed burning time of oil and coal being too long,bad atomization of heavy oil gun,combustion adjustment being no in time in later coal feeding,et al. Finally,according to these reasons,the corresponding preventive measure of coking was put forward,whose effect was obvious: there was no coking in bed material and the region nearby oil gun shield.

Aiming at adapting to the load fluctuation in power grid,the unit coordinated control(UCC)system frequently regulates the power of each generation unit to ensure the equilibrium and stability of power grid.Thus,the UCC system of a supercritical unit was taken as the research object to conduct investigation on its dynamic characteristics.Through simulation experiment,the response characteristics of two typical UCC strategies to primary frequency regulation and automatic generation control(AGC)were compared.The results showed that,with two different combinations of boiler master control system and turbine master control system,when the dead band and speed drop were constant,the continuous variation of main steam pressure mainly depended on the boiler master control system;when small disturbance occurred,the main factor was the turbine master control system;while in large disturbance condition,the fluctuations of different boiler master control systems' parameters may exceeded the pressure control dead band,causing change of the turbine master control system's outputs,which will affect the system output seriously.

Based on the emulation system of CFB boiler equipped for supercritical 300 MW unit in Mengxi Power Plant,the control strategy of bed temperature has been presented,and three main affecting factors upon bed temperature,namely coal quantity,primary air flow rate,and circulating ash quantity,have been tested using emulation and quantitatively analysed.Results show that the primary air flow rate in operation of unit will change as the coal quantity changes.Through method of changing the circulating ash quantity,the bed temperature can be effectively adjusted.

The paper briefs the major features of main part and system design of circulating fluidized bed (CEB)boiler;emphatically analyzes the important contents and existing problems in the commissioning debugging process of larze size circulating fluidized bed boiler;in view of the debugging praetice of HG-480/137-L.MG21 type CFB boiler (burning Yangquan anthracite),puts forward the following debugging optimization scheme of:air quantity calibration,high temperature refractory curing,steam blow-cleaning,furnace heating surface protection,going into operation time and mode of loop seal system, going into operation of main fuel,coalfeeding control and under-bed igniting burner etc.

The development of dynamic mathematical model for emulation system of supercritical 600 MW oncethrough boiler unit has been presented in this paper, some analyses using dynamic mathematical model for supercritical oncethrough boiler units being emphasized, and the behavior of dynamic process of realtime emulation model for oncethrough boiler units being approached.