ABSTRACT

The reliability of water distribution system (WDS) involves imprecise or uncertain parameters. For hydraulic reliability, the uncertain parameters include roughness coefficient, nodal water demand, and the reservoir water level, etc. While water quality reliability is primarily related to chlorine concentrations, with uncertainty parameters including both bulk decay coefficients and wall decay coefficients. The uncertain independent parameters lead to the uncertain results of reliability simulation. As such, fuzzy set theory was proposed to analyze the reliability of WDS and associated belief degree (BD) of calculated reliability. The proposed method was applied to two examples to solve the uncertainty in traditional reliability assessment. The system reliability and BD of WDS were obtained by assumed three uncertainty levels. In addition, the sensitivity analysis of uncertain independent parameters was performed to compare the effects of parameters on simulated reliability and associated BD. The proposed method can help municipalities to make scientific pipe network programming to improve the reliability of WDS.

摘要

配水系统 (WDS) 的可靠性涉及不精确或不确定的参数。对于水力可靠性，不确定参数包括粗糙度系数、节点需水量和库水位等。而水质可靠性主要与氯浓度有关，不确定参数包括体积衰减系数和壁面衰减系数。不确定的独立参数导致可靠性仿真结果的不确定性。为此，提出了模糊集理论来分析 WDS 的可靠性和计算可靠性的相关置信度 (BD)。将所提出的方法应用于两个实例，以解决传统可靠性评估中的不确定性。WDS 的系统可靠性和 BD 是通过假设的三个不确定性水平获得的。此外，对不确定的独立参数进行敏感性分析，以比较参数对模拟可靠性和相关 BD 的影响。该方法可以帮助市政当局进行科学的管网规划，提高WDS的可靠性。