联合循环和海水淡化耦合的梯级余热利用技术  

Cascade Waste Heat Utilization Technology coupled by CCPP and Seawater Desalination

作　　者：李永康 徐琳涛 宁罡 吕蒙 何振宇 LI Yong-kang;XU Lin-tao;NING Gang(Xi’an Branch of North China Electric Power Research Institute Limited Liability Company;North China Electric Power Research Institute Limited Liability Company)

机构地区：[1]华北电力科学研究院有限责任公司西安分公司,陕西西安710065 [2]华北电力科学研究院有限责任公司

出　　处：《电站系统工程》2021年第3期39-41,44,共4页Power System Engineering

摘　　要：针对钢铁企业自备电厂余热丰富、沿海分布的特点,介绍了一种由联合循环和海水淡化耦合的梯级余热利用技术。该技术可回收副产煤气用于联合循环发电,实现对余热资源的第一、二级利用。将汽轮机乏汽引入海水淡化装置,利用乏汽内能对海水进行蒸馏,降低冷源损失,同时生产数量可观的除盐水、浓盐水,并将淡化海水蒸汽用来预热原海水,实现对余热资源的第三、四级回收。经计算,海水淡化环节对冷源损失的回收比例达到88.23%,系统的直接热效率提高42.8%,等效发电热耗率降低840 kJ/(kW·h),等效发电热效率提高5.6%。与常规联合循环机组相比,系统的余热利用水平显著提高。According to the characteristic of rich waste heat resources and coastal distribution of self-provided power plants in iron and steel enterprises,a cascade waste heat utilization technology coupled by CCPP and seawater desalination is illustrated,in which the byproduct gas is recovered for combined cycle power generation,achieving the primary and secondary utilization of waste heat.The exhaust steam of the turbine,whose internal energy is recycled for distilling sea water,is introduced into the desalination device,where the loss of cold source is greatly decreased,a considerable amount of desalted water and concentrated brine is produced,and the desalted seawater steam is used to preheat the raw seawater,accomplishing the third and fourth stage utilization of the waste heat.By calculation,the recovery efficiency of the system to the cold source loss is up to 88.23%,the direct thermal efficiency is increased by 42.8%,the equivalent generating heat consumption rate of generation is reduced by 840 kJ/(kW·h),and the equivalent heating efficiency of generation is increased by 5.9%.Compared with the conventional CCPP,the waste heat utilization level of the system is substantially improved.

关 键 词：海水淡化 冷源损失 热效率 经济性 

分 类 号：TM621[电气工程—电力系统及自动化]