河北工程学院毕业设计（论文）1摘要热系统变工况是指系统的工况发生变动，偏离设计工况或者偏离某个基准工况。热系统工况发生变动的原因是多方面的，比如机组热、电负荷变化，热系统及设备发生变动(含改造)以及蒸汽初、终参数发生变动等等都将引起热系统工况发生变化。因为变工况的影响因素很多，并且这些因素又互相制约，这就使得汽轮机的变工况特性非常复杂。热系统的变工况，无论它产生的原因如何，其表现出的特点均是汽轮机的进汽流量或级组通过的蒸汽流量发生变动，其产生的直接结果是级组的各抽汽参数和热系统的有关参数发生变化，并表现为汽轮机膨胀过程线的变化。热系统变工况特性分析的目的在于确定汽轮机各抽汽口和排汽端的蒸汽参数以及回热系统的各相应参数，其实质是确定汽轮机新的膨胀过程线和系统参数，这是热系统变工况的安全性与可靠性分析以及经济指标计算分析的基础。关键词: 变工况 热负荷 热经济性 AbstractOff-heat system is the system operating conditions change, the status of or deviation from the design operating conditions deviate from a benchmark. Thermal system operating conditions change are many reasons, such as the Heat, electricity load changes, thermal changes in systems and equipment (including transformation), as well as the early steam, and 河北工程学院毕业设计（论文）2finally change the parameters so the system will be caused by thermal changes in working conditions . Because of the impact of variable condition of a number of factors, and these factors and each other, making the variable condition of steam turbine characteristics is very complicated. Thermal system with variable working condition, no matter how it causes, its manifestations are the characteristics of the turbine steam flow into the group or class of steam flow through the changes, the generated class group is a direct result of the extraction parameters and thermal system parameters change, and performance for the turbine expansion process line changes. Thermal Systems Analysis of changes in working conditions to determine the extraction steam turbine and the exhaust port side of the steam heat system parameters, as well as all corresponding parameters, and its essence is to determine the turbine expansion process of the new line and system parameters, which change the thermal system condition of the safety and reliability analysis and the analysis of economic indicators based on the calculation.Key words: Off-heat system heat load Thermal economy河北工程学院毕业设计（论文）3目录第 1 章 绪论 .41.1 加热器运行状态对机组热经济性的影响 .41.2 热力系统简介.4第 2 章 原始工况计算 .62.1 选择主机型号及参数.62.2 热系统计算.72.2.1 汽水平衡计算 .72.2.2 汽轮机进汽参数计算 .82.3 各加热器进、出水参数计算.82.4 高压加热器组抽汽系数计算.102.5 低压加热器组抽汽系数计算.112.6 凝汽系数 c计算.132.7 汽轮机内功计算.132.8 汽轮机内效率，热经济指标、汽水流量计算.142.9 全厂性热经济指标计算.16第 3 章 变工况计算 .183.1 原始工况计算结果.183.2 汽轮机初始通流量计算.183.3 初步计算.193.4 第一次迭代的预备计算.213.5 第一次迭代计算.