火电厂废水零排放技术及应用研究

Research on Zero Discharge Technology and Application of Waste Water in Thermal Power Plants

改造工程主要包括循环水排污水回收处理系统的技改、渣系统零溢流技改、高含盐废水浓缩减量处理系统技改、末端废水蒸发结晶处理系统技改以及其它系统的技改,具体内容涉及水处理系统概况、处理工艺技术、改造过程分层次概述、投资估算以及经济评价等。首先,针对于常见的水处理系统概况进行归纳总结,包括供水系统、循环水系统以及脱硫系统的基本概况进行分类整理;其次,针对于常见的几种废水类型的工艺技术进行概括,包括蒸发浓缩处理技术、电渗析工艺技术、烟道雾化蒸发技术以及蒸汽机械再压缩蒸发结晶技术进行简要的理论概述;最后,全厂废水“零排放”改造工程分为全厂水务管理及梯级利用、废水软化及浓缩减量处理、末端废水处理三个层次进行改造,改造费用分别为2725万元、4746万元和1870万元(静态投资,不包括基本预备费和其他费用)。预计某电厂全厂废水零排放改造工程实施后,2×320 MW机组发电水耗将由目前的2.42 m^(3)/(MW·h)降低至1.75 m^(3)/(MW·h)。DTRO-旁路烟道蒸发方案年运行总成本为1868万元,增加上网电费为6.95元/MWh。

According to the actual situation of water source water quality,existing water treatment facilities and operation conditions of a power plant,the“zero discharge”technical renovation project of wastewater in the whole plant mainly includes technical renovation of circulating water and sewage recycling and treatment syste,zero overflow technical renovation of slag system,Technical transformation of high-salt wastewater concentration and reduction treatment system,technical transformation of terminal wastewater evaporation and crystallization treatment system,and technical transformation of other systems,the specific content involves the general situation of water treatment system,treatment technology,hierarchical overview of transformation process,investment estimation and economic evaluation wait.Firstly,summarize and summarize the general overview of common water treatment systems,including the basic overview of water supply system,circulating water system and desulfurization system;Secondly,summarize the technology of several common types of wastewate,including evaporation and concentration treatment technology,electrodialysis process technology,flue atomization evaporation technology and steam mechanical recompression evaporation and crystallization technology for a brief theoretical overview;Finally,the whole plant wastewater“zero discharge”renovation project is divided into the whole plant water management and cascade utilization,wastewater softening and concentration The three levels of reductiontreatment and terminal wastewater treatment will be reconstructed,and the reconstruction costs will be 27.25 million yuan,47.46 million yuan and 18.7 million yuan respectively(static investment,excluding basic reserve and other expenses).It is estimated that after the implementation of the zero-emission wastewater discharge renovation project of a power plant,the water consumption for power generation of 2×320 MW units will be reduced from the current 2.42 m^(3)/(MW·h)to 1.75 m^(3)/(MW·h).The total annual operating cost of the DTRO-bypass flue evaporation scheme is 18.68 million yuan,and the additional on-grid electricity fee is 6.95 yuan/MWh.