Pump-As-Turbine (PAT) technology is a smart solution to produce energy in a sustainable way at small scale, e.g., through its exploitation in classical Water Distribution Networks (WDNs). PAT application may actually represent a suitable solution to obtain both pressure regulation and electrical energy production. This technology enables one to significantly reduce both design and maintenance costs if compared to traditional turbine applications. In this work, the potential hydropower generation was evaluated through laboratory tests focused on the characterization of a pump working in reverse mode, i.e., as a PAT. Both hydrodynamic (pressure and discharge) and mechanical (rotational speed and torque) conditions were varied during the tests, with the aim to identify the most efficient PAT configurations and provide useful hints for possible real-world applications. The experimental findings confirm the good performances of the PAT system, especially when rotational speed and water demand are, respectively, larger than 850 rpm and 8 L/s, thus leading to efficiencies greater than 50%. Such findings were applied to a small municipality, where daily distribution of pressure and discharge were recorded upstream of the local WDN, where a Pressure Reducing Valve (PRV) is installed. Under the hypothesis of PRV replacement with the tested PAT, three different scenarios were studied, based on the mean recorded water demand and each characterized by specific values of PAT rotational speed. The best performances were observed for the largest tested speeds (1050 and 1250 rpm), which lead to pressure drops smaller than those actually due to the PRV, thus guaranteeing the minimum pressure for users, but also to mechanical powers smaller than 100 W. When a larger mean water demand is assumed, much better performances are reached, especially for large speeds (1250 rpm) that lead to mechanical powers larger than 1 kW combined to head drops a bit larger than those observed using the PRV. A suitable design is thus fundamental for the real-world PAT application.

中文翻译：

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水泵作为涡轮机的水力发电：实验研究及在小规模 WDN 中的潜在应用

水泵涡轮机 (PAT) 技术是一种以可持续方式小规模生产能源的智能解决方案，例如，通过在经典配水网络 (WDN) 中进行开发。PAT 应用实际上可能代表了一种合适的解决方案来获得压力调节和电能生产。与传统的涡轮机应用相比，这项技术可以显着降低设计和维护成本。在这项工作中，通过实验室测试评估了潜在的水力发电，重点是在反向模式下工作的泵的特性，即作为 PAT。在测试过程中，流体动力（压力和排放）和机械（转速和扭矩）条件都发生了变化，目的是确定最有效的 PAT 配置，并为可能的实际应用提供有用的提示。实验结果证实了 PAT 系统的良好性能，特别是当转速和需水量分别大于 850 rpm 和 8 L/s 时，从而导致效率大于 50%。此类调查结果适用于一个小城市，记录了当地 WDN 上游的每日压力和排放分布，在那里安装了减压阀 (PRV)。在用测试的 PAT 替换 PRV 的假设下，研究了三种不同的情景，基于平均记录的需水量，每种情景都以特定的 PAT 转速值为特征。在最大测试速度（1050 和 1250 rpm）下观察到最佳性能，这导致压降比 PRV 造成的实际压降要小，从而保证了用户的最小压力，而且机械功率也小于 100 W。当假设更大的平均需水量时，可以达到更好的性能，特别是对于大型导致机械功率大于 1 kW 的速度 (1250 rpm) 导致压头下降比使用 PRV 观察到的略大。因此，合适的设计是实际 PAT 应用的基础。特别是对于导致机械功率大于 1 kW 的大速度 (1250 rpm) 导致的压头下降比使用 PRV 观察到的要大一些。因此，合适的设计是实际 PAT 应用的基础。特别是对于导致机械功率大于 1 kW 的大速度 (1250 rpm) 导致的压头下降比使用 PRV 观察到的要大一些。因此，合适的设计是实际 PAT 应用的基础。