（毕业设计论文）《火电机组加热器端差对经济性影响的分析》.doc

火电机组加热器端差对经济性影响的分析 摘 要：讨论汽轮机组的经济性问题，人们往往把目光放在汽轮机的初终参数上，认为它们的变化对机组的经济性影响较大，这无疑是正确的。但分析整台机组的经济性仅限于此也是不全面的。还应关注汽轮机的回热系统，因为汽轮机的回热系统也有相当的节能潜力，认真分析其中存在的问题，也能找到节能的途径和办法 ，其中汽轮机热力系统中的加热器的运行情况,对机组经济性有较大的影响，主要表现在加热器的端差（包括运行中的加热不足）、抽汽管道压损、散热损失、切除加热器和给水部分旁路等因素对热经济性的影响。定量分析这些因素对热经济性的影响，对于机组节能和提高机组热经济性具有十分现实的意义。在这些因素中，传热端差的影响尤其大，本文运用等效热降理论，以600MW和350MW机组为例定量分析了加热器端差变化对机组热经济性的影响，结果表明加热器端差越小,机组的热经济性越高, 加热器端差越大,机组的热经济性越低，这为电厂给水回热系统节能改造提供了依据，本文还总结了加热器端差增大的原因，并提出了相应的改进措施。 关键词：加热器，端差，等效热降法，经济性 The Analysis of Thermal Economicon Terminal Temperature Difference of Heater in Power Unit Abstract ：Disscussing the economic issuses of turbine, people tend to pay a attention to the initial and final parameters of the turbine, and think their changes will effect greatly on unit’s economy , which is undoubtedly correct. However, it is comprehensive to simply analyze . the economy of the entire unit. Because the heat recovery system of steam turbine has considerable potential for energy saving, we should also concern heat recovery system of steam turbine, and analyze the existing problems carefully to find the ways to energy saving. Heater terminal temperature difference of steam turbine thermal system can cause great infections on unit’s economy,and it mainly expresses the impacts about heater terminal temperature difference , the loss of pressure along pipe ,the loss of heat, the resection of high pressure feedwater heater ,and the bypass of supplying water,and so on.Analyzing the impact on unit’s hot economy by these factors has realistic significance for the unit’s energy saving and improving the unit’s hot economy. The terminal temperature difference influence greatly among these factors.This paper took the 600MW and 350MW units as an example, equivalent heat drop method was adopted for analyzing heater terminal temperature difference effect on unit’s economic. The results indicated:the smaller heater terminal temperature difference, the higher unit’s economic; the bigger heater termina