燃煤锅炉掺烧生物质气运行效率及污染物排放模拟  

Simulation on operation efficiency and pollutant emissions of coal-fired boiler with bio-gas co-firing

作　　者：张小桃[1] 李柯颖 赵伟[1] 黄勇 Zhang Xiaotao;Li Keying;Zhao Wei;Huang Yong(North China University of Water Resources and Electric Power,Zhengzhou 450011,China)

机构地区：[1]华北水利水电大学,郑州450011

出　　处：《农业工程学报》2018年第11期194-202,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：河南省教育厅自然科学研究计划项目(2011A140014);河南省科技发展计划项目(112102210281)

摘　　要：为解决生物质直燃给锅炉带来的运行问题,以及燃煤锅炉掺烧秸秆气对运行性能以及污染物排放的影响,建立了秸秆气化及秸秆气与煤混合燃烧模型,且对模型的气化过程与燃烧过程进行了合理验证。为保证锅炉稳定运行,设置进入锅炉系统的总热值不变,在不同秸秆含水率、秸秆气掺烧比例及炉膛过量空气系数下,研究锅炉运行性能及污染物排放变化规律。结果表明:与纯煤燃烧相比,当掺烧比和含水率从10%增大到30%,混燃温度降低,最大降幅为89.3℃;在5%～30%秸秆含水率及10%～30%秸秆气掺烧比例下,空气预热器出口处排烟体积、排烟密度、排烟质量均有变化,掺烧后锅炉效率变化范围为92.72%～93.71%,系统效率变化范围为88.75%～92.62%;空气预热器出口处烟气中NO与SO_2排放浓度随掺烧比增大均减小,10%掺烧比例条件下,过量空气系数增大,NO排放浓度先增大后稍有下降,SO_2排放浓度减小。该研究为实现生物质的合理应用并减小已有燃煤电厂的污染物排放提供了理论依据。As a kind of rich renewable energy in China, biomass has become an important research direction for energy conservation and emission reduction and sustainable development. Most of biomass utilization can be used to generate power. In recent years, biomass co-firing with coal combustion technology has been widely developed. Because biomass gasification technology is more mature and has many applications, the biomass gas co-firing technology in a coal-fired boiler becomes the new research direction of biomass which can be used to generate electricity. Additionally, as one of the most abundant biomass energy in China, straw is the main object in this thesis. Meanwhile, the different combustion characteristics of straw gas and coal entail certain changes in combustion process and pollutant emissions. In order to solve the problem of boiler operation caused by biomass fuel performance during the direct co-firing of biomass and coal, the co-firing process of biomass gas and coal is introduced, and based on the design and operation data of a 330 MW pulverized coal boiler, the models of straw gasification and straw gas co-firing with coal were established by Aspen Plus, and the models were reasonably verified. Due to that the fuel characteristics of biomass have changed after the biomass gasification, the influence of coal-fired boiler co-firing straw gas on boiler operation performance and the change of pollutants were studied, so as to provide valuable reference for research work of biomass used in boiler co-firing. The whole model consists of the following 3 processes： the gasification process of straw, in which the air is selected as gasification agent and straw gas and straw ash will be obtained from the gasifier and the energy conservation will be realized in this process; the co-firing process of straw gas and coal in coal-fired boiler; the heat exchange process of heat transfer in tail. In this whole process, the heat exchange between the medium in super-heater, re-heater, economizer and air pre-heater and the

关 键 词：秸秆 生物质 锅炉 ASPEN Plus模拟仿真 效率 污染物排放 

分 类 号：TK6[动力工程及工程热物理—生物能]