水汽风速放大计算可能最大暴雨方法探讨

我国可能最大暴雨(PMP)计算中,通常采用两种放大方法,即水汽效率放大和水汽风速放大,但一般认为水汽风速放大成果不稳定,结果往往偏大,所以通常只作参考,最后基本上都选取水汽效率的放大结果作为最终的设计成果.借鉴港口工程设计中“风玫瑰图”概念,对传统水汽风速放大方法进行改进,即先根据研究区域常风向对实测风速资料进行风向分组,对每组风向的典型暴雨进行放大,再从中选取最大值作为水汽风速的放大成果,为PMP计算提供了一种新的思路.以湖北省咸宁核电厂为例进行了应用研究,并与水汽效率放大方法和传统水汽风速放大方法结果进行了比较,提供了更为合理的分析成果.

Study on moisture and wind maximization for probable maximum precipitation estimation

Generally,moisture and efficiency factor maximization or moisture and wind maximization are two approaches used to estimate the probable maximum precipitation (PMP) in China.But only the value obtained from the moisture and efficiency factor maximization is used as the PMP estimation in most cases,because the moisture and wind maximization approach regularly overestimates and therefore is usually taken as reference only.This paper presents a modified moisture and wind maximization method based on the "Wind Rose Diagram" applied in port engineering.First,measured wind speed and direction data are grouped according to the direction of prevailing wind in the studied area.Then,the high-efficiency storm in each group of wind direction is maximized.Finally,the maximum value among all groups is chosen to be the final result of moisture and wind maximization,that is PMP value.The new approach was tested on the Xianning nuclear power plant in Hubei Province,and generated a more reasonable PMP value compared with the traditional approaches.