锅炉过热器进口集箱三通区域静压分布的数值模拟及三通的结构改进

Numerical simulation on static pressure distribution in T-junction headers of boiler superheater and the improvement of its structure

为解决过热器超温爆管问题,根据电站锅炉过热器带三通集箱的结构特点,采用数值模拟方法对采用径向引入方式的过热器进口集箱三通区域的静压分布和流动规律进行了研究,并在此基础上对三通区域结构进行了改进.结果表明:三通区域集箱中存在涡流区,使该区域的静压变低,导致布置在该区域的支管蒸汽流量减少;适当增大三通区域集箱内径可提高集箱涡流区的静压,但当三通区域集箱内径增大到一定程度后,继续增大三通区域集箱内径,集箱涡流区的静压已不再有明显升高.

To overcome the tube burst failures caused by overtemperatureof boiler superheater, numerical simulation study on the static pressure distribution and flow mechanismof the T-junction zone in the radial leading-in headers was performed according to its structural characteristics. Furthermore,the structure of T-junction was improved. The results showed that there were vortexes in the header near the T-junction which caused the drop of the static pressure. Thereby, the steam flux of the branches which was close to this area decreased. The static pressure increased by enlarging the inner diameter of the header in a proper range. Beyond this range the enlargement of the diameter would not increase the static pressure significantly.