烟道流场三维集成优化在超净改造中的应用

The Application of Three-dimensional Integration Optimization of Flue Flow Field in Supernet Modification

华能海门电厂#2机组超净改造前引风机出口烟气呈对冲汇流状,该布置形式的烟道流场比较差,阻力较大,煤质差时甚至会影响机组额定负荷出力,尤其超低排放改造采用低低温技术路线,烟气汇冲之后经过急转弯进入二级烟冷器,除尘器出口至吸收塔入口系统阻力较大。为确保超净改造后除尘器出口至吸收塔入口烟道,引风机、二级烟冷器、吸收塔等设备进出口烟气流场更加顺畅,将引风机移动至脱硫吸收塔入口对侧,利用原增压风机基础及支架,并对除尘器后至引风机出口烟道进行重新设计和深度优化,将两侧除尘器6个烟气出口汇合至总烟道,并分别进入移过来的两台引风机入口,与原系统比较,烟风系统阻力大幅下降;并消除了原布置引风机出口90°急转弯处导流板在烟气反复应力的作用下造成撕裂堵塞流道的引起停机的隐患,且两台风机烟道独立,提高了机组运行的安全性。

The flue gas at the outlet of the draft fan of No. 2 unit in Huaneng Haimen Power Plant takes on the state of- hedging before the uhra-clean transformation. The flue flow field is poorly distributed, which will even affect the unit rated load output when the quality of coal is not good, especially when the low-temperature technical route is adopted during the low-emission transformation. After the flue gas flushes, it flows through a sharp turn into the secondary cool- er where the resistance is large from the dust collector exports to the absorption tower entrance system. After the ultra- clean transformation, to ensure the smooth gas field distribution of the whole system, which include the dust collector outlet to the absorption tower entrance flue, induced draft fan, two chillers, absorption tower and other equipment, the induced draft fan is moved to the opposite of the entrance of desulfurization absorption tower. The blower fan base and support being utilized and the flue from the dust collector to the induced draft fan being redesigned and deeply opti- mized, 6 flue gas exports on both sides of the filter are converged to the total flue, and then move into the entrance to the two sets of induced draft fan. Compared with the original system, the risk of downtime is eliminated, which is the consequence of the tearing of the runner under the action of the repeated stress of the flue gas of the original layout . What＇ s more, the two turbine flues are in dependent, which improvesthe security of the unit operation.