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近几年来，随着国民经济的迅速发展，电网负荷的峰谷差不断增大，大机组参与调峰已成为一种趋势，要求机组能快速而频繁的启停变负荷运行．高的启停速度导致汽包热应力提高，高的热应力及调峰引起的频繁波动将引起金属材料的疲劳和损伤，从而影响汽包的安全性和寿命．特别对于参与调峰的大机组，由于其锅炉汽包多为厚壁受压容器，机组启停速度越快，起停次数越多，其低周疲劳寿命越低．本文结合电站锅炉，论述汽包低周疲劳寿命的估算方法．１计算实例北仑港电厂１号６００ＭＷ机组配套锅炉．该炉系美国燃烧工程公司制造，亚临界控制循环，四角布置直流式燃烧器，锅炉容量２００８ｔ·ｈ－１，蒸汽参数１８．２ＭＰａ／５４０／５４０．汽包有关技术参数如下：单汽包（不等壁厚），汽包下部有６根大直径下降管；汽包材料ＳＡ－２９９型；汽包内径Φ内＝１７８８ｍｍ；汽包上壁厚ＳＹ上＝１９８．４ｍｍ；汽包下壁厚ＳＹ下＝１６６．７ｍｍ；汽包额定工作压力１９．５ＭＰａ；冷启动工作范围０～１９．５ＭＰａ；热启动工作范围：１０～１９．５ＭＰａ；温升率Ｖ＝±１℃·ｍｉｎ－１，Ｖ＝±１．５℃·ｍｉｎ－１；表１为与汽包材料ＳＡ－２９９型相对应的物性参数．表１ＳＡ－２９９型材料物性参数温度?
In recent years, with the rapid development of the national economy, the peak load and discharge of power grids have been increasing. It has become a trend for large units to participate in peak regulation, requiring the units to start and stop variable load operation quickly and frequently. High start-stop speed led to thermal stress in the drum, high thermal stress and frequent fluctuations caused by the peak will cause fatigue and damage to the metal material, thus affecting the safety and life of the drum. Especially for the large units involved in peak regulation, the boiler drums are mostly thick-walled pressure vessels, the faster the unit start and stop, the more the starting and stopping times, the lower the low-cycle fatigue life. In this paper, combined with the power station boiler, discusses the drum low cycle fatigue life estimation method. 1 Calculation Example Beilun Port Power Plant No. 1 600MW unit supporting boiler. The furnace is manufactured by the U.S. Burning Engineering Company, subcritical control cycle, four-corner layout of the DC burner, the boiler capacity of 2008t · h-1, steam parameters 18.2MPa / 540/540. Drum-related technical parameters are as follows: single drum (ranging from wall thickness), the lower part of the drum has six large diameter drop tube; steam drum material SA-299 type; drum diameter Φ = 1788mm; drum thickness SY On the = 198.4mm; drum under the wall thickness SY = 166.7mm; drum rated working pressure 19.5MPa; cold start working range 0 ~ 19.5MPa; hot start working range: 10 ~ 19.5MPa; temperature rise V = ± 1 ℃ · min-1, V = ± 1.5 ℃ · min-1. Table 1 shows the physical parameters corresponding to SA-299 type of drum material. Table 1SA-299 type material properties of the material temperature?