【作者】 杨涛；

【导师】 苟小龙；

【作者基本信息】 重庆大学 ， 动力工程及工程热物理， 2016， 硕士

【摘要】 汽轮机作为火力发电和核能发电机组最重要的设备之一,其自身的性能及其调节系统的特性直接关系到整个机组运行的安全性和经济性。随着机组复杂性的增大和优化运行与精细化管理的需要,传统的模型难以获得满足精度要求的系统动静态特性以及数量庞大的参数之间的耦合关系。在该背景下,亟需寻求具有实用价值的更为详细准确的数学模型和高效的参数分析手段。针对传统模型存在的难以详细反映机组部分动态过程的问题,通过对既有模型的分析和改进,建立能够更加详细准确地反映汽轮机调节系统动态特性的数学模型。同时,对系统的动、静态性能受相关参数的影响程度进行了不确定性分析,为提高模型的精度和优化试验过程创造条件。论文的主要工作及成果如下:(1)为了能够更加详细准确地反映机组的动静态特性,根据各相关设备的工作原理及实测数据,对部分传统模型进行改进,完善了汽轮机及其调节系统的各环节模型以及系统整体模型结构。(2)基于所建立的数学模型,根据某300MW和某600MW机组的设计、运行参数以及现场试验的实测数据,对机组的汽轮机调节系统的动态过程进行了模拟。计算结果与传统BPA模型以及实测数据的对比分析,表明本文提出的改进模型具有更高的精度和适用性。(3)为了分析模型相关参数对主要计算结果的影响,采用蒙特卡罗法进行了参数不确定性分析。主要讨论了高压缸蒸汽容积时间常数、再热器蒸汽容积时间常数和低压连通管道蒸汽容积时间常数等参数的变动对汽轮机及其调节系统动态行为及稳态精度的影响,为构建实用的准确反映对象特性的数学模型以及制订合理的现场试验方案提供了新的分析手段。本文建立的汽轮机及其调节系统的数学模型有效地提高了模拟精度,所建模型及不确定性分析方法可作为大型火电及核电机组汽轮机及其调节系统优化运行的分析工具。更多还原

【Abstract】 Steam turbine is one of the most important facilities of thermal power plants and nuclear power plants, its performance and the governing system features have great influence on the security and economy of the unit. Because of the unit’s complexity and the demand of optimizing operation and delicacy management, traditional model is hard to achieve the precision requirements of static and dynamic characteristic of system. It’s essential to establish a model with high precision and find an efficient way to analyze the key parameters of the steam turbine governing system.Since the traditional model hardly reflects some of the system’s dynamic characteristics, an improved mathematical model is proposed in this thesis based on the traditional model, which can reflect more accurately the dynamic characteristics of the steam turbine governing system. Meanwhile, through the analysis of parameters uncertainty on the system’s dynamic behaviors and stability, the results which can be used to improve the accuracy of the model and optimize the test process are obtained.The main work and achievements of this thesis are listed as follows:(1) According to the basic principles and practical measured data of relevant devices, an improved steam turbine governing system model is established based on traditional model. The proposed mathematical model can reproduce the system characteristics in detail.(2) Through the comparison with traditional BPA model, the novel steam turbine governing system model has performance of higher accuracy and applicability based on the measured data from a 300 MW thermal unit and a 600 MW thermal unit.(3) In order to analyze the influence of parameters variation on the main calculating results, the results uncertainties due to the variation of time constant of main inlet volumes and steam chest, time constant of the reheater, time constant of crossover piping and low pressure inlet volumes are analyzed through the Monte Carlo Method. It provides a reliable means for developing a reasonable test scheme and building a practical model.The mathematical model established in this thesis effectively increases the simulation accuracy. The model and the uncertainty analysis method can be used as an analysis tool to optimize the operation process and controlling strategy of the thermal or nuclear steam turbine.更多还原