【作者】 刘焕章；

【导师】 刘吉臻； 常太华；

【作者基本信息】 华北电力大学（北京） ， 热能工程， 2008， 博士

【摘要】 现代电站的生产受到越来越苛刻的环保条件限制,特别是自《京都议定书》和GB13223-2003《火电厂大气污染物排放标准》生效以来。本文以电站锅炉的排放物为研究对象,通过对排放物的分析,来判断炉内燃烧过程的状态。论文主要的研究内容分为以下几个方面:(1)通过对煤燃烧过程的机理分析和对我国电力用煤的煤质统计分析并结合锅炉燃烧排放物的在线测量,建立一个锅炉的入炉煤质的在线测量模型。建模的原理基于燃烧排放物与燃烧状态和煤质密切相关,通过排放物反推煤质具有科学性;同时,为了使模型可解,通过统计规律补足方程个数。(2)通过机理分析和统计规律建立的模型需要丰富的排放物信息,而实际生产过程中由于设备原因或者技术原因,很多排放物并未得到有效的测量和监测。论文中通过机理分析和统计规律,建立了诸如煤的含湿量和燃烧产物中的二氧化碳含量等参数的软测量模型。通过其它已知或易知的量,实现了对模型中未知或者难知量的间接计算。(3)通过模型得到在线的煤质后,燃烧的控制问题就归结为一个风煤配比的问题,论文通过对煤质修正后的空气过量系数的优化来提高燃烧过程的经济性。该部分内容没有对经济性进行直接的论述和计算,而是通过煤质修正的空气过量系数这个中间参数实现对锅炉经济燃烧的指导。论文还通过对典型工况的空气过量系数与优化空气过量系数的比较分析,指出了相应工况下存在的问题。(4)论文中将电站锅炉的燃烧行为看作一个经济过程去考查,建立了该过程的经济输出和输入比,其中输入中包含了环保收费。通过对输出输入比的标幺化,得到了一个有着传统热效率表现形式的电站广义效率指标,并通过该指标对电站的生产过程的经济环保性进行了分析和考查。典型工况的经济环保性分析也是以该指标为量度的。(5)论文以广义效率指标最大化为目标函数,对机组间的负荷优化分配进行了探讨研究。通过以广义效率最大化为目标的优化方案与实际的负荷分配方案以及与传统的煤耗率最低为目标的负荷分配方案的比较,得到了“按照以广义效率为指标的分配方案未必能提高单台机组的经济环保性,但对于整个电站的经济环保生产是大有裨益”的结论。更多还原

【Abstract】 The operation of modern power plants is limited by more and more strict environmental rules, especially after Effectiveness of Kyoto Agreement and GB13223-2003 emission standard of air pollutants for thermal power plants took effect. My thesis researched into emissions of utility boilers, which aimed at judging combustion state based on emission analysis. Main content of my thesis can be summarized as follows:(1) An on-line monitoring model was built via analyzing mechanism of combustion process, achieving statistic laws of elements component of coal which was for power generation , and on-line measuring emissions. The methodology is based on the fact that emissions are products of coal combustion and combustion state, so calculation of coal information according to emissions is logical, meanwhile, statistic laws making the model usable.(2) The model, which bases on mechanism and statistic laws, needs much emissions information, however, part of information is unattainable because of equipment reason or technical reason in practical terms. In my thesis, soft-sensor models, such as water in coal, CO2 content in flue gas and so on, were built by indirect computation of measurable or easy-securable parameters.(3) After coal elements component can be attained on-line, the key point to control is the ratio of air and coal. Thesis tried to improve combustion economic performance via the excess air ratio, which had been amended via coal elements component. Thesis did not illustrate and calculate the economic index directly, and had the amended excess air ratio to supervise combustion. Thesis applied the amended excess air ratio to analyze representative operation states to point out their deficiency.(4) Combustion was taken as an economic process to build its ratio of output and input, while environmental charges were included in input. After standardizing, an efficiency index in general, which had a similar appearance to conventional thermal efficiency, was built. The efficiency index in general was used as measurement of representative operation states.(5) Optimization load distribution was studied, whose aim was maximizing the efficiency index in general. Comparison among distribution according to the efficiency index in general, practical load distribution and distribution according to coal consumption was made to achieve the conclusion that efficiency in general of single unit is unnecessarily improved after optimization load distribution according to the efficiency index in general, but efficiency in general of the whole power plant must be improved.更多还原