基于纳滤的火电厂循环冷却水分质浓缩研究  

Selective concentration treatment of circulating cooling water in thermal power plants based on nanofiltration technology

作　　者：宋肖磊 梁帅[1] 辛宇晨 余智勇 丁昊杰 李业 周建文 黄霞[3] SONG Xiaolei;LIANG Shuai;XIN Yuchen;YU Zhiyong;DING Haojie;LI Ye;ZHOU Jianwen;HUANG Xia(College of Environmental Science and Engineering,Beijing Forestry University,Beijing 100083,China;Suzhou Qingqiji Technology(Group)Co.,Ltd,Suzhou 215200,China;School of Environment,Tsinghua University,Beijing 100084,China;China Huaneng Group Clean Energy Technology Research Institute Limited,Beijing 102209,China;China Huaneng Xilingol Cogeneration Co.,Ltd,Xilinhot 026000,China)

机构地区：[1]北京林业大学环境科学与工程学院,北京100083 [2]苏州青骐骥科技(集团)有限公司,苏州215200 [3]清华大学环境学院,北京100084 [4]中国华能集团清洁能源技术研究院有限公司,北京102209 [5]中国华能锡林郭勒热电有限责任公司,锡林浩特026000

出　　处：《膜科学与技术》2024年第6期78-87,共10页Membrane Science and Technology

基　　金：华能集团总部科技项目“基础能源科技研究专项(三)(HNKJ22-H105)”资助。

摘　　要：推进分质梯级用水和废水近零排放是当前火力发电行业绿色转型阶段的重要发展方向.火电厂循环冷却水因水量大但循环利用不足而成为当前发展面临的瓶颈问题.本研究针对循环冷却水水质特点,提出基于纳滤技术进行冷却水分质浓缩的处理方案.对一、二价离子进行选择性分离,将富含Ca^(2+)、Mg^(2+)的浓水用于辅助烟气脱硫;将净水回用于循环冷却工段,旨在控制冷却塔结垢等问题的同时,提升火电厂整体水资源利用率.系统对比了5种商业纳滤膜(NF245、NF270、DF30、DF90、XCN)的分质浓缩特性.优选并使用XCN膜对实际循环冷却水进行纳滤分质浓缩,在10%水回收率时可实现对Ca^(2+)、Mg^(2+)大于97%的高截留,而对Na+的截留率稳定在20%,离子选择性S Na/Mg和S Na/Ca分别可达36.7和30.5,展现出良好的应用潜力.Promoting quality-based and gradient water usage and near-zero wastewater discharge is an important development content in the current green transformation stage of the thermal power industry.The circulating cooling water of thermal power plants has become a bottleneck due to its large volume but insufficient recycling and reuse.In this study,based on the characteristics of circulating cooling water quality,the concentration treatment of cooling water was proposed based on nanofiltration technology,the selective separation of mono-/di-valent ions was carried out,the concentrated water rich in Ca^(2+)and Mg^(2+)was used for auxiliary flue gas desulfurization,and the clean water was returned to the circulating cooling section,aiming at controlling the scaling problems of cooling towers and improving the overall utilization rate of water resources in thermal power plants.In this study,the mass concentration characteristics of five commercial nanofiltration membranes(NF245,NF270,DF30,DF90 and XCN)were compared.The XCN membrane was selected and used for nanofiltration separation treatment of practical circulating cooling water,which could achieve high rejection of Ca^(2+)and Mg^(2+)greater than 97%,while the rejection rate of Na+was stable at 20%.At 10%water recovery,the ion selectivity of S Na/Mg and S Na/Ca could reach up to 36.7 and 30.5,showing good application potential.

关 键 词：火电厂 循环冷却水 纳滤 选择性分离 水回用 

分 类 号：TQ028.3[化学工程]