场次暴雨情景下变电站地下排水性能的有效评估

Effective evaluation of underground drainage performance in substations under episodic heavy rainfall scenarios

摘要

【目的】完善的地下排水系统对于提升暴雨情景下变电站地下管网的排水能力和确保电力设施的安全运行具有重要意义。【方法】以广东省揭阳市某待建变电站为研究区，设计了一种新的地下排水系统，并提出了“圆管模型”和渗流模型耦合模拟的等效渗透系数方法，构建了应对场次暴雨情景的地下管网排水效果评价数值模型。通过对变电站建设前的地下水调查数据进行参数校准，评估了新排水系统在6种暴雨情景下的排水流量、地下水位动态变化以及积水区的时空分布特征。【结果】结果表明：新的地下排水系统能够有效排水并降低管网周边的地下水位。暴雨后变电站核心区的地下水位变化呈现缓慢上升和缓慢下降的趋势，而周边地下水位则表现出快速上升和快速下降的规律。在50 a一遇和100 a一遇的小时和分钟暴雨情景下，新地下排水系统表现出优良的性能，不会出现积水现象；然而，研究区西南侧出现明显积水，且持续7 d的暴雨所形成的积水在4 d后方可消退。【结论】基于等效渗透系数方法模拟的场次暴雨情景下新的地下排水系统排水能力较好，可为变电站排水管网排水能力的评估及优化设计提供一种有效手段。

Abstract

[Objective] A well-developed underground drainage system is crucial for enhancing the drainage capacity of underground pipeline networks in substations under heavy rainfall scenarios and ensuring the safe operation of power facilities. [Methods] Taking a planned substation in Jieyang City, Guangdong Province, as the study area, a new underground drainage system was designed. An equivalent permeability coefficient method, coupling the “circular pipe model” and the seepage model, was proposed. A numerical model was established to evaluate the drainage performance of the underground pipe network under episodic heavy rainfall scenarios. By calibrating parameters using groundwater survey data before the construction of the substation, the drainage flow, groundwater level dynamics, and the spatiotemporal distribution characteristics of water accumulation areas under six heavy rainfall scenarios were assessed. [Results] The result showed that the new underground drainage system could effectively drain water and reduce groundwater levels around the pipeline network. After heavy rainfall, the groundwater level in the core area of the substation exhibited a trend of gradual rise and slow decline, while the surrounding groundwater levels demonstrated a pattern of rapid rise and rapid decline. Under the 50-year and 100-year return period hourly and minute-scale heavy rainfall scenarios, the new underground drainage system exhibited excellent performance, with no water accumulation. However, under daily-scale heavy rainfall scenarios of the same return periods, significant water accumulation occurred in the southwestern part of the study area, and the accumulated water from a continuous 7-day rainfall event took 4 days to recede. [Conclusion] The new underground drainage system, simulated using the equivalent permeability coefficient method under episodic heavy rainfall scenarios, demonstrates good drainage capacity, which provides an effective approach for evaluating and optimizing the drainage capacity of substation drainage networks.

关键词

排水管网 / 数值模拟 / 暴雨情景 / 地下水 / 变电站 / 等效渗透系数法

Key words

drainage network / numerical simulation / heavy rainfall scenarios / groundwater / substation / equivalent permeability coefficient method

基金资助

清华大学-宁夏银川水联网数字治水联合研究院专项统筹重点项目(SKL-IOW-2023TC2307)

国家自然科学基金核技术创新联合基金项目(U2167211)

广东揭阳惠来园区输交电工程项目(0352004823220005)