Abstract Hot-water storage in residential and commercial tanks is of growing interest for peak-shifting the electrical demand associated with hot-water loads. How the water enters the tank can significantly affect the extraction efficiency of the storage. Vertical-tube inlets (VTIs) direct cold water into the tank. The VTI design influences whether large-scale mixing occurs, which can reduce the delivery capacity of the hot-water storage. In this work, the mixing at the VTI discharge was characterized by the eddy diffusivity factor (EDF) in an allometric curve fit to the ratio Re:Ri using inlet superficial velocities. The full experimental campaign tested VTI's with Re’s between 170 and 22,300 and Ri's between 0 and 376. Animated visualization of the experimentally measured data is provided, showing tank temperature evolution during inlet flows. The most predictive correlations for EDF are for VTI Re in the transition zone (i.e. ~2300 5). For vertical-tubes that distribute cold water below the thermocline, increasing the EDF will decrease the stratification in a hot-water tank as EDF quantifies inlet mixing. The new correlations for VTIs can be used to design and model thermally-stratified storage tanks.

中文翻译：

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热水储罐立管进水口的实证表征

摘要 住宅和商业水箱中的热水储存越来越引起人们对与热水负载相关的电力需求的峰值转移的兴趣。水如何进入水箱会显着影响存储的提取效率。垂直管入口 (VTI) 将冷水引导到水箱中。VTI 设计影响是否发生大规模混合，这会降低热水储存的输送能力。在这项工作中，VTI 排放处的混合通过使用入口表面速度拟合 Re:Ri 比的异速生长曲线中的涡流扩散系数 (EDF) 来表征。完整的实验活动测试了 VTI，Re 介于 170 和 22,300 之间，Ri 介于 0 和 376 之间。提供了实验测量数据的动画可视化，显示在入口流动期间罐温度的变化。EDF 最具预测性的相关性是过渡区（即~2300 5）中的 VTI Re。对于在温跃层下方分配冷水的垂直管，增加 EDF 将减少热水箱中的分层，因为 EDF 量化入口混合。VTI 的新关联可用于设计和建模热分层储罐。