基于设计暴雨法的CSO调蓄池池容计算方法探讨

我国当前采用经验参数法计算合流制溢流(CSO)调蓄池池容,该方法存在参数取值合理性不足、CSO控制效果不清等问题。基于暴雨强度公式和合理法,提出与溢流频次控制标准相对应的设计暴雨,并分别根据简化的三角形径流过程线、由设计降雨过程线得到的径流过程线,给出了CSO溢流口溢流量(调蓄池池容)和污水处理厂厂前溢流量计算方法。以北京为例,拟合得到CSO调蓄池池容与径流截流比、历时24 h设计降雨径流量之间的关系曲线,可供北京城区使用。设计暴雨法可在一定程度上弥补我国当前参数法的不足,为CSO调蓄池池容的合理设计提供参考。

Determination Method of CSO Calculation Volume of Storage Tank Based on Design Rainstorm Method

At present,empirical parameter method is adopted to calculate the combined overflow system(CSO)storage tank volume in China.This method has some problems,such as the lack of ratioality of parameter value and the control effect of CSO is not clear.Based on the storm intensity formula and reasonable method,the corresponding design rainstorm for overflow frequency control standards was proposed.According to the simplified triangular runoff line and the runoff line obtained from the design rainfall process line,the calculation methods of CSO overflow(storage tank capacity)and pre-plant overflow in WWTP were given respectively.Taking Beijing as an example,the relationship curve between the capacity and runoff diversion ratio of the CSO storage tank volume,as well as the designed rainfall runoff of 24 h was obtained by fitting,which can be used in Beijing urban area.The design rainstorm method can make up for the deficiency of the current empirical parameter method in China to some extent,and can provide reference for the reasonable design of CSO storage tank volume.