电厂制粉系统防爆与控制的研究

发布时间：2018-03-29 14:36

本文选题：球磨机　切入点：制粉系统　出处：《浙江大学》2014年硕士论文

【摘要】：电力工业是国民经济基础产业为工业和国民经济其他部门提供基本动力,是国家经济发展中最重要的基础能源产业。近年来,随着电力行业的快速发展,电煤的需求急剧增加,受电煤价格等因素的影响,电煤供应紧张,煤炭价格居高不下。国内许多电厂纷纷开始选用价格较低但挥发份含量较高的煤,导致燃烧的电煤煤种达不到最初设计的要求,挥发份过高。由于难以保证燃烧设计的煤种,在燃用高挥发分煤种时,制粉系统运行时极易产生自燃、爆炸等隐患,严重时会导致设备损坏以至威胁人身安全。本文针对中间储仓式球磨机制粉系统出现的爆炸和自燃现象,以专业知识为指导,通过查阅大量相关国内外资料,详细阐述制粉系统爆炸的机理,深入分析球磨机制粉系统爆炸事故的原因,总结了制粉系统相关设备和系统的防爆改造措施。研究表明制粉系统爆炸事故主要原因在于煤和煤粉的积存以及球磨机出口温度控制不当等情况,针对目前运行中大多数电厂的中间储仓式制粉系统的球磨机控制都比较落后的现象,提出用智能预测控制代替传统的PID控制,通过加强对球磨机出口温度等的控制来降低球磨机制粉系统爆炸的可能性,加强制粉系统的安全运行。此外论文还综述性地介绍了中储式球磨机制粉控制系统的控制要求和控制难点、控制方法和存在问题以及建模特性等,并对制粉系统磨煤机进行模型预测控制与PID控制仿真和效果分析比较,证明模型预测控制相比于常规PID控制,球磨机出口温度等参数的控制效果有明显改善。这对进一步开展这方面的应用和研究有一定的指导意义。
[Abstract]:The electric power industry is the basic industry of the national economy, which provides the basic power for the industry and other departments of the national economy, and is the most important basic energy industry in the national economic development. In recent years, with the rapid development of the electric power industry, the demand for thermal coal has increased sharply. Influenced by the price of thermal coal and other factors, the supply of electric coal is tight and the price of coal remains high. Many domestic power plants have begun to choose coal with lower price but higher volatile content, resulting in the burning of thermal coal falling short of the original design requirements. The volatile content is too high. Because it is difficult to ensure the combustion design of the coal, when burning the high volatile coal, it is easy to produce the hidden trouble such as spontaneous combustion, explosion and so on when the pulverizing system is operated, which will lead to the equipment damage and even threaten the personal safety seriously. According to the phenomena of explosion and spontaneous combustion in the pulverizing system of the intermediate storage type ball mill, the mechanism of the explosion of the pulverizing system is explained in detail by referring to a large number of relevant domestic and foreign data and guided by professional knowledge. The cause of explosion accident in pulverizing system of ball mill is analyzed in depth, and the measures of explosion proof and reformation of relevant equipment and system of pulverizing system are summarized. The research shows that the main causes of explosion accident of pulverizing system are the accumulation of coal and pulverized coal and improper temperature control at the outlet of ball mill. In view of the fact that the ball mill control of the middle storage pulverizing system in most power plants is backward at present, the intelligent predictive control is proposed to replace the traditional PID control. By strengthening the control of the outlet temperature of the ball mill to reduce the possibility of explosion in the pulverizing system of the ball mill, In addition, the paper also introduces the control requirements and control difficulties, control methods, existing problems and modeling characteristics of the pulverizing control system of the ball mill. The model predictive control of pulverized coal mill is simulated and compared with that of PID control. It is proved that the model predictive control is compared with the conventional PID control. The control effect of parameters such as outlet temperature of ball mill is obviously improved, which has certain guiding significance for further application and research in this field.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM621

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