《建筑给水排水设计标准》设计秒流量计算方法商榷及改进

Discussion and Modification on Design Flow Calculation Methods in Standard for Design of Building Water Supply and Drainage

对《建筑给水排水设计标准》(GB 50015—2019)居住类建筑的生活给水管道设计秒流量计算方法进行了数学解析,指出此计算方法的理论依据不足,按此计算方法得到的秒流量值在小规模管网必定偏大、在大规模管网必定偏小。分析了该标准中旅馆、酒店类平方根法给水设计秒流量计算方法存在的问题,指出此计算方法不适合较大规模的给水管网;分析了该标准中含大便器自闭式冲洗阀生活给水管道设计秒流量计算方法存在的问题,算例揭示按此计算方法得到的秒流量值严重偏小;分析了该标准中生活排水设计秒流量计算方法存在的问题,揭示此设计秒流量计算值偏小。提出概率法设计秒流量计算方法可以解决以上问题,该方法比现行标准中的计算方法更加科学、简单、安全、准确。

Design flow calculation method for residential building domestic water supply pipeline in Standard for Design of Building Water Supply and Drainage(GB 50015-2019)was mathematical analyzed.It was found that the calculation method was lack of theoretical basis,and the design flow obtained by this calculation method must be too large in small-scale pipe network,and too small in large-scale pipe network.Problems existing in calculation method of design flow by square root method for inns and hotels in the standard were analyzed,and it was found that this calculation method was not suitable for large-scale water supply networks.The problems existing in the design flow calculation method for domestic water supply pipeline design with toilet self-closed flushing valve in the standard were analyzed,and the calculation examples revealed that the design flow obtained by this method was too small.The problems existing in the design flow calculation method for domestic drainage in the standard were analyzed,which also indicated that the calculation value was too small.It was proposed that probability design flow calculation method could solve the above problems,and the method is more scientific,simple,safe and accurate than calculation methods in the current standard.