300MW机组热力部分局部初步设计 兰州交通大学.docxVIP

兰州交通大学毕业设计(论文)  PAGE \* MERGEFORMAT 40 兰州交通大学毕业设计(论文) 摘 要 300MW级燃煤机组是我国在近阶段重点的火力机组，由于300MW发电机组具有容量大，参数高，能耗低，可靠性高，对环境污染小等特点，今后在全国将会更多的300MW级发电机组投入电网运行。 本次设计为300MW机组热力部分局部初步设计,设计在进行设计选型时仅依照安全经济的标准进行优化没有考虑其他影响因素。设计主要内容如下；第一，是对发电厂主要设备的确定，主要是汽轮机，锅炉型号的选择。汽轮机的选择包括汽轮机进汽压力、温度、结构的选择，锅炉部选择部分包括锅炉最大连续蒸发量，过热器出口压力，温度，锅炉效率,汽包压力的选择。第二，是对锅炉燃烧系统及其设备的选择锅炉，燃料选择义马烟煤，根据煤的成分分析选择磨煤机，然后选择制粉系统， 最后选择合适的风机。第三，是原则性热力系统的拟定和计算。第四，汽轮机辅助设备的选择，凝汽式发电厂应选择凝汽式机组。其单位容积应根据系统规划容量，负荷增长速度和电网结构等因素进行选择。辅机一般都随汽轮机本体配套供应，只有除氧器水箱、凝结水泵组、给水泵、锅炉排污扩容器等，不随汽轮机本体成套供应。第五，进行全面性热力系统的拟定，其中系统的拟定包括主蒸汽管道系统的拟定，再热机组旁路系统的拟定，给水管道系统的拟定，回热加热器管道系统的拟定，除氧器管道系统的拟定，补充水管道系统的拟定，排污扩容器及排污冷却器管道系统的拟定，轴封管道系统的拟定，制粉系统的拟定等。第六，绘制机组局部全面性热力系统图。 关键词：汽轮机,锅炉,热力系统，辅机形式  Abstract? This?design?is?once?complete?fossilfired?power?plant?dynamic?system?designs.The?design?for?the?thermal?part?of?the?300MW?unit?of?local?preliminary?design,?the?design?during?the?design?selection?only?in?accordance?with?the?standards?of?safety?and?economic?optimization?does?not?take?into?account?other?factors. First,choosing?the?main?equipment?in?the?power?plant?includes?choosing?the?turbine?and?boiler.Which?includes?the?steam?turbine?inlet?pressure,temperature,structure?and?boiler?maximum?continuous?evaporation,superheated?steam?outlet?pressure,temperature,?boiler?efficiency,.drum?pressure.Second,making?the?choice?between?boiler?combustion?system?and?its?equipments:YI?Ma?bituminous?coal?is?our?choice?fuel?in?boiler,?coal?pulverizer?according?to?composition?analysis?choice,?then?is?the?system?power?system,?finally?is?proper?fan.Third,?sketching?of?the?power?plant?principal?thermodynamic?system?and?calculation.Forth,choosing?the?main?equipments?of?machine?in?steam?turbine?that?lends?support?to?the?equipments:?The?condenser?type?should?suit?condenser?type?machine?.?Its?unit?capacity?should?program?the?capacity?according?to?the?system,?carrying?to?increase?the?peed?to?proceed?the?choice?with?power?grid?consideration?construction?etc.?Assist?the?machine?to?suppl