毕业设计--300MW机组火电厂机务部分初步设计.docVIP

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，主要是汽轮机结构、参数的选择和通流部分的分级，锅炉型号是燃烧系统及设备的选择和制粉系统的确定。第二，是对原则性热力系统的拟定。第三，是原则性热力系统的计算。第四，是对汽水流量和热经济指标的计算。第五，是热力系统辅助设备的选择，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。第六，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，及绘制机组局部全面性热力系统图。 本次设计充分借鉴铁岭电厂设备选型和设计。 关键词：汽轮机,锅炉,热力系统，辅机形式。 Abstract This design is once complete fossil-fired 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:XU ZHOU 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 supply with the steam turbine essence kit generally and all, only divided by deaerat