黄冈大别山发电有限责任公司2号机组经超净排放改造后,锅炉燃烧特性发生变化,原有自动控制逻辑及参数不能满足电网的要求,并且2号机组在中低负荷段出现屏式过热器出口壁温超温现象;同时,变负荷过程中机组主蒸汽压力、主蒸汽温度、再热蒸汽温度等主要参数波动较大,导致机组负荷变化率低,仅为3.5 MW/min,不能满足电网相关规定.对此,在不经机务改造的前提下,利用多变量协同控制,优化滑压曲线,对一次风压设定曲线、氧量设定曲线、中间点温度设定曲线及风煤比设定函数进行修改,重新设计自动控制策略,动态协同控制进入炉膛的燃料量、给水流量和总风量.优化后,2号机组在AGC方式下实际负荷变化率达到9 MW/min,主要参数变化平稳,解决了屏式过热器出口壁温超温问题.

Currently, the automatic generation control(AGC) frequency modulation technology for the combination of thermal power unit and energy storage system is booming in the power industry of China. This study introduces the basic principle, the typical scheme, control process and practical engineering effect of this technology. And the impact of energy storage system access on the electrical system of thermal power units and the selection of energy storage batteries are discussed. In addition, the investment and profit of the engineering application of this technology are analyzed. The results show the AGC frequency modulation technology for the combination of thermal power unit and energy storage system has a significant effect and good economic benefits. And the energy storage system access has basically no effect on the control system and the electrical system of thermal power units. Besides, lithium iron phosphate battery has advantages as a battery of energy storage system. This study provides a reference for engineering application of the AGC frequency modulation technology for the combination of thermal power unit and energy storage system.

机组甩负荷试验是大型汽轮发电机组上网运行的必备条件.在甩负荷过程中,由于机组参数变化幅度较大,因此控制系统在手动方式下难以控制各参数.对此,根据机组甩负荷过程特点,对汽轮机高/低压旁路控制系统、锅炉主控系统的相关控制回路等进行了设计和优化,并提出了新的给水控制策略.机组50％、75％甩负荷试验结果表明,控制系统在自动方式下,机组转速控制正常,锅炉燃烧稳定,各主要参数变化平稳,机组具备重新快速并网的能力,提高了控制系统在机组甩负荷工况下的控制品质,从而保证了机组和电网运行安全性.

The circulating fluidized bed(CFB)boiler has good adaptability and variable load capacity,but its large thermal inertia and hysteresis and strong coupling relations between parameters lead to difficulty in putting the automatic control function into service.Therefore,the 330 MW CFB unit manufactured by Harbin Boiler Factory was regarded as the control object,optimization on the major analog coordinated control system was performed,on the basis of ensuring the balance of material,heat and energy between the machine and furnace and so on.After the optimization,the response speed of fuel amount variation on the main steam pressure deviation was improved,and the strong coupling,large inertia and nonlinear of the main steam pressure,bed temperature and bed pressure were overcome.Moreover,the temperature and bed pressure of the CFB with double feet and double grid-plates structure were balanced.

基于对串级控制系统积分饱和的分析,提出了改变PID2和修改PID1闭锁条件2种抗积分饱和方式,并基于Matlab平台对2种方式进行了仿真分析,结果表明修改PID1闭锁条件的抗积分饱和方式既可有效避免串级控制系统PID1的积分饱和,又能保证PID2的快速调节.

A shut-down accident occurred in a power plant because of turbine's partial frequency operation. The main reasons of frequent fluctuations of steam temperature behind high and low pressure bypass in HP casing exhaust lie in high metal temperature, which is caused by the closed non-return valve and the heavy turbine load. Meanwhile, the harm to turbines caused by the removal of high pressure cylinder under large load is analyzed. Finally, some suggestions on logical configuration of partial frequency protection, desuperheating water of low pressure bypass and non-return valve are proposed in HP casing exhaust. The operation practice show that the logical configuration scheme could avoid accidents and be safe and reliable.