600MW超临界机组给水系统控制分析与运行

发布时间：2018-08-11 16:06

【摘要】：在全球能源和煤炭日益减少的背景下,为满足我国国民用电同时为经济的发展提供可靠的保障,发电厂的发电机组向着高参数、大容量的方向发展已经势在必行,而超临界机组在现代火力发电机组中担当着国家能源电力稳定的重任。在超临界机组各子系统间的强耦合性和机组的蓄热能力不强的双重原因作用下,超临界机组的给水由液态到汽态转换时间很短,所以对给水系统的控制提出了更严格的标准。与传统的汽包锅炉相比,超临界机组采用的直流锅炉系统具有多变量、强耦合、非线性的特点,常规的控制方案已经达不到运行要求,为使超临界机组能够长期优良稳定经济的运行,采用先进的给水控制方案是必然的。本文结合宁夏京能宁东发电厂2×600MW超临界机组的给水控制系统的设计特点,对超临界机组给水系统的控制策略进行了定性研究,并根据多年工作经验对超临界机组给水系统的运行方式进行了全面分析。本文提出了采用以煤水比为方向的给水控制,同时分析中间点温度和中间点焓值两种校正信号控制方式的优缺点,并选择适用宁夏京能宁东发电厂的给水量校正方式,在宁东电厂的运行环境中,选择中间点焓值的自动给水控制是保证控制主蒸汽温度的同时确保机组安全经济稳定运行的最佳方式。本文的重点工作是分析直流锅炉启态和湿态运行阶段的给水控制特点,提出运行的操作方式;其次,对直流工况下的给水控制逻辑进行研究,并根据机组的实际情况对升降负荷进行分析;最后对机组的重要辅机在突减负荷(RB)的工况下进行试验分析,并研究调节过程。
[Abstract]:Under the background of decreasing global energy and coal, in order to meet the demand of electricity and provide reliable guarantee for the development of economy, it is imperative for the generator set of power plant to develop in the direction of high parameter and large capacity. Supercritical units play an important role in national energy and power stability in modern thermal power generation units. Due to the strong coupling between subsystems of supercritical units and the weak heat storage capacity of supercritical units, the conversion time of feed water from liquid state to steam state is very short, so a more strict standard is put forward for the control of feed water system. Compared with the traditional drum boiler, the once-through boiler system used in the supercritical unit has the characteristics of multivariable, strong coupling and nonlinearity. In order to make the supercritical unit run steadily and economically for a long time, it is necessary to adopt advanced water supply control scheme. According to the design characteristics of feed water control system of 2 脳 600MW supercritical unit in Ningxia Jingneng Ningdong Power Plant, the control strategy of feed water system of supercritical unit is studied qualitatively in this paper. The operation mode of feed water system of supercritical unit is analyzed comprehensively according to the working experience of many years. In this paper, a feed water control system with coal-water ratio as the direction is proposed, and the advantages and disadvantages of two correction signal control methods, namely, the intermediate temperature and the enthalpy value of the intermediate point, are analyzed, and the water supply correction method suitable for Ningxia Jingneng Ningdong Power Plant is selected. In the operating environment of Ningdong Power Plant, it is the best way to control the main steam temperature and ensure the safe, economical and stable operation of the unit by selecting the automatic feed water control of enthalpy at the middle point. The main work of this paper is to analyze the characteristics of feedwater control in the stage of once-through boiler's start-up and wet operation, and to put forward the operation mode. Secondly, the logic of feed-water control under the direct current condition is studied. According to the actual situation of the unit, the lifting load is analyzed. Finally, the important auxiliary machine of the unit is tested and analyzed under the condition of sudden load reduction (RB), and the adjustment process is studied.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM621

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