【作者】 顾倩；

【导师】 王明春；

【作者基本信息】 东南大学 ， 动力机械及工程， 2005， 硕士

【摘要】 论文主要致力于火电站大型再热机组性能在线监测算法模型的研究,主要包括以下几个方面的内容:1.性能监测常规算法介绍。系统地介绍具有实时数据库平台的机组性能在线监测系统中所需要的一些适合实时计算的常规模型,包括数据预处理模型、锅炉算法模型、汽轮机算法模型以及辅机单耗算法模型。2.热力系统性能计算方法研究。本文提出了热力系统能效分布矩阵方程,热力系统能效分布矩阵方程是在常规热平衡法、q ?γ?τ矩阵形式和等效焓降等基础上提出的。能效分布矩阵方程中的每个矩阵物理意义明确、规律性强,可以使热力系统的整体计算和局部分析变得更加清晰、简单、客观。算例表明,能效分布矩阵模型具有物理意义明确、数学描述简洁、便于并行计算等特点。3.基于BP神经网络的汽轮机排汽焓计算方法的研究。汽轮机排汽点处于湿蒸汽区,由于现场缺乏蒸汽湿度的测量手段,排汽焓值难以直接确定,其计算取值一直是火电机组热力系统热经济性在线分析诊断的难点之一。影响排汽焓的因素很多,它们与排汽焓之间属于典型的非线性关系。本文利用BP神经网络良好的非线性映射能力,以平圩N600-165/535/535机组为例,介绍了应用BP神经网络建立汽轮机排汽焓计算模型的方法。更多还原

【Abstract】 Models of on-line performance monitoring arithmetic in reheating units are researched in the thesis. The main contents and achievements of the thesis are as follows:1. Introduction of general algorithm models in on-line performance monitoring system. Such as data pre-handling models, boiler arithmetic models, turbine arithmetic models, auxiliaries arithmetic models, etc.2. Research on performance calculating for thermal system. The power-efficiency distributing matrix equation for thermal system is developed in this thesis, which is developed on the basis of conventional thermodynamic methods, q ?γ?τmatrix and equivalent enthalpy drop. Each matrix of the power-efficiency distributing matrix equation has a explicit physical sense and strong regular form, which makes it simple, clear, objective for global calculation and local analysis in thermal system. Samples show that the power-efficiency distributing matrix model has the characteristic of clear physical meaning, sententious mathematic description and convenient to parallel calculation.3. Research on calculating enthalpy of the exhaust steam released by turbine with BP neural network. The steam released by turbine is in the wet steam area, so its enthalpy is hard to fix for the lack of means to measure the steam humidity in the local area. Its calculation has always been one of the difficulties of on-line analysis and diagnosis of the thermal economy for thermal power generation units. Many factors determine the exhaust steam enthalpy, which have typical nonlinear relationship with the exhaust steam enthalpy. Considering the better nonlinear mapping ability of BP neural network, the method of establishing the model to calculate the exhaust steam enthalpy with BP neural network is introduced in this thesis, which takes Ping Wei N600-165/535/535 units as an example.更多还原