过热器分配集箱三通区域静压分布试验研究

Experimental study on the static pressure distribution in the T-junction of the distribution header

热偏差与汽温偏差是大型电站锅炉过热器与再热器系统运行过程中存在的主要问题,也是导致过热器与再热器受热面超温爆管的主要原因。过热器与再热器系统采用三通引入、引出结构会产生较大的蒸汽流量偏差和热偏差,甚至导致受热面超温爆管。针对某660 MW超临界锅炉炉顶过热器分配集箱三通区域部分管子超温爆管问题,根据该过热器分配集箱的三通引入结构及受热面布置特点,对进口三通区域的静压分布进行试验研究,揭示了三通两侧分流比、三通区域支管分流比不同时三通涡流区的影响范围、三通涡流区不同部位以及三通两侧集箱的静压分布规律,指出进口三通区域涡流是该锅炉炉顶过热器超温爆管的主要原因,并提出了行之有效的对策。

The thermal deviation and steam temperature deviation are the main problems during the operation of superheater and reheater systems of large utility boilers, and also the main cause for the tube failure of superheaters and reheaters. The T-junction inlet and outlet mode of steam in the superheater and reheater system can result in obvious steam flow deviation and thermal deviation, and even the tube failure. An experimental study on the static pressure distribution in the T-junction was conducted to analyze the cause for the tube failure in the T-junction of the roof superheater distribution header in a 660 MW super critical boiler, according to the structure characteristics of the T-junction inlet of the distribution header and the arrangement of tubers of the roof superheater. The coverage of the vortexes and the static pressure distribution in the T-junction at different conditions were revealed.The main cause for the tube failure of the roof superheater is the vortexes in the T-junction. The effective countermeasure is put forward.