侧风下分区配水对冷却塔性能的影响研究

Effect of partition water distribution on cooling performance of wet cooling towers with cross wind

分区配水能通过改善传热传质区域的气水比来提高冷却塔冷却效率,其实际运行过程中侧风的影响不容忽视。以某超大型湿式冷却塔为对象,利用三维数值模拟方法研究了环境风速v=1~3 m/s时,出塔水温、冷却效率、通风量和蒸发损失在不同分区配水方案下(内区配水量占比在5%~95%变化)的变化趋势。结果表明:以风速v=3 m/s为例,随内区配水量占比的增加,出塔水温先减小后增大,冷却效率、通风量和蒸发损失先增大后减小;当内区配水量占比为65%时,出塔水温比均匀配水(内区配水量为60.68%)时降低了约0.14℃,冷却效率提高了0.82%;同时,风速v=1~3 m/s时,分区配水的出塔水温均低于均匀配水,冷却效率均高于均匀配水。因此,在低风速下,与均匀配水方案相比,分区配水方案能有效降低冷却塔的出塔水温、提高冷却效率。

Partition water distribution can enhance the cooling efficiency of cooling tower by improving the gas-towater ratio in heat transfer area,and the effect of cross side wind during actual operation process cannot be ignored.By taking a super-large scale wet cooling tower as the research object,three dimensional numerical simulation method is applied to study the change trend of outlet water temperature,cooling efficiency,ventilation and evaporation loss with water distribution in the inner zone accounting for 5%~95%at wind speed v=1~3 m/s.The results indicates that,when v=3 m/s,with the increase of the proportion of water distribution in the inner zone,the outlet water temperature decreases at first and then increases,and the cooling efficiency,ventilation and evaporation loss increases at first and then decreases.When the proportion of water distribution in the inner zone is 65%,compared with the uniform water distribution(the proportion of water distribution in the inner zone is 60.68%),the outlet water temperature reduces by 0.14℃and the cooling efficiency increases by 0.82%.Meanwhile,when the wind speed is 1~3 m/s,the outlet water temperature of partition water distribution is lower than that of the uniform water distribution,and the cooling efficiency is higher than that of the uniform water distribution.Therefore,comparing with the uniform water distribution,partition water distribution can effectively reduce the outlet water temperature and improve cooling efficiency at low wind speed.