【作者】 刘杰；

【导师】 黄勇理；

【作者基本信息】 华中科技大学 ， 热能工程， 2016， 硕士

【摘要】 富氧燃烧技术凭借其易规模化捕集CO₂、捕获成本相对较低、污染物排放可控、可改造存量机组等优势成为碳减排领域研究热点。区别于常规电厂,富氧电站风烟系统工艺流程存有差异,而对此类流程中烟气特性参数及系统运行操控的研究,则是未来广泛应用富氧燃烧技术的重要准备工作。文章先阐述了富氧燃烧技术的主要特点、参数监控要求以及依托实验运行过程得到的关于风烟系统工艺流程的经验准则;再以35MWth富氧燃烧电站风烟系统为研究对象,从机理建模角度入手,在合理简化基础上,分别建立起风烟系统稳态Excel计算模型和Simulink动态仿真模型,并以实验数据为模型输入,将得到的仿真结果与DCS测量数据相互对比,以验证模型是否准确。通过稳态模型进行仿真,可探究系统负荷、漏风、脱水性能、配风注氧方式对于烟气流量及组分特性、风烟系统运行操控的影响。此外,基于稳态模型构建过程中涉及到的变量,以及调试时各参数间的相互作用关系,可为富氧燃烧风烟系统相关运行参数的测点配置、仪表选型提供依据。动态模型采用集总参数法对风烟系统设备进行简化,主要包含烟气温压计算、辐射传热、单相介质换热等子模块,可探究系统初始参数如给粉量、送风量、送风温度及负荷增减等出现波动时,模型烟气侧温压及换热的变化。依托风烟系统动态模型建立的简易PID控制模型,可探究模型动态响应特性及烟温调控性能,并为后续参数调控及优化提供基础。本文研究内容是富氧燃煤电站风烟系统基础理论及运行控制研究的重要组成部分,可为富氧电站实际运行时风烟系统的调控提供参考。更多还原

【Abstract】 The oxy-fuel combustion technology has great advantages in aspects like capturing CO₂ easily on large scale, relatively low capturing cost, controllable pollutant emission and plenty reformable power plants. All of these preponderances make it a hot research spot in field of carbon abatement. Distinct from conventional power station, the oxygen-enriched power plant’s air/gas system has different technical processes. Study of flue gas characteristic parameters and air/gas system manipulation over above processes is an important preparatory work for the widely application of oxygen-enriched combustion technology in the future.Firstly, the main features of oxy-fuel combustion technology, parameter monitoring requirements and air/gas system technical processes’ experimental principles on basis of laboratorial actual operation were elaborated in this paper. Then, regarding 35 MWth oxy-fuel combustion power station’s air/gas system as the object, a steady-state Excel calculation model and a dynamic simulation model using Simulink were built from the perspective of mechanism modeling and rational simplification. With experimental datas as model input, the model accuracy was verified after comparing simulation results with measured values from DCS.Through model simulation, impacts of factors like system loading, air leakage, dewaterability, air distribution and oxygen injection methods on flue gas amount, its component properties and manipulation of air/gas system were to explore and study. Over the time of establishing steady-state model, the variables involved and interaction between various parameters during model debugging can provide basis for measuring point arrangement and instrument selection of related runing parameters of oxy-fuel combustion air/gas system.Gathered parameter method was used in dynamic model to simplify the actual air/gas system facilities. Some submodules like flue gas temperature and pressure calculation module, radiation heat transfer module and single-phase medium heat transfer module were consisted in the dynamic model which could be applied to investigate the changing process of model flue gas side temperature, pressure and heat exchange under disturbances such as coal-powder input, air supply volume or its temperature, system loading increasing or decreasing. Based on the built model, a simple PID regulator was added to explore dynamic response characteristics and flue gas temperature adjustment performance of the model system which could provide a well basis for subsequent running parameter adjustment and optimization.The content of research in this paper is an important part of basic theory and operation control study of oxy-fuel coal-fired power plant’s air/gas system, which can be referred during actual operational control of real oxygen-enriched air/gas system.更多还原