预分解窑余热发电系统配置的合理性探讨及技术方案

Technical scheme and rationality discussion on power generation system allocation for PC kiln by using remnant heat

在配置余热发电系统时,不能简单将水泥生产系统的规模作为余热发电系统配置的条件,其生产能力要考虑实际增产幅度和相应的热耗指标,如果不能预期生产能力增长幅度,建议按正常生产规模富余10%考虑;篦冷机的抽风点应尽可能向热端移动,可靠近煤磨抽风点或共用煤磨抽风口。在考虑系统布置时,尽量使煤磨烘干的热源从窑尾锅炉出口抽取。选择余热发电系统时,应结合热量回收率、经济性、操作维护的难度综合考虑,特别是系统中窑头锅炉的省煤器布置有多种组合方案,且可考虑带除氧的布置,对热量的充分回收会有不同的效果。如果水泥生产中窑头工况波动大,推荐采用单压系统,以保证系统安全可靠。除氧方式应根据给水质量和水泥企业的具体情况进行选择。

During design of power generation system by using remnant heat,the rated capacity of cement production system can not be simply deemed as preconditions for power generation system allocation,and the actual possible maximum production ability and its relative heat consumption targets should also be considered.In case the maximum production ability can not be predicted,it is suggested that adding 10% margin to the rated capacity should be considered. The exhaustion point for hot gas from grate cooler should be located as close as possible to the high temperature end,and can close to or even use the same exhausting outlet for coal mill.During system allocation design,the heat source for coal mill drying should be exhausted from the outlet of SP boiler (near preheating tower) as far as possible.In design of power generation system,the heat recovery rate,systematic profitability,suitability for operation and maintenance should comprehensively considered;especially for the economizer arrangement at AQC boiler (near grate cooler),there are several combination proposals,including the arrangement with deoxidization device,resulting in different effects for sufficient recovery of heat energy.If the fluctuation of operational conditions for kiln head is great in production,it will be recommended to adopt mono-pressure system for ensuring safety and reliability of the system.Deoxidization method can be selected according to supplying water quality and the actual condition of the cement plant.