Abstract An efficient storage retains thermal stratification and improves the discharging performance. Turbulent mixing between hot and cold water is the prime source of stratification destruction. In this paper quantification of turbulent missing was achieved on the basis of temperature profile, MIX number, and Richardson number. The evaluated parameters include flow rate, ΔT, and diffuser design, henceforth a direct interdependence between each was thus established. Various CFD models were developed and experimentally validated on the test rig in order to find the optimal working conditions in discharge mode. The results proved numerically that the tank working conditions can be optimized by proper selection of inlet device. For instance, slotted type inlet device sustained maximum stratification even in as adverse a condition as of turbulent inflow & low ΔT. Perforated and simple inlet devices were capable of delivering best discharge efficiency only at low flow rate of 200 l/h and were showing insignificant dependency on ΔT. However, as flow rate is increased, ΔT dependency increased. Seeing the compounded benefits of slotted inlet devices and decreased ΔT, it was concluded that slotted inlet device delivered comparatively better thermal performance at both adverse conditions i.e. high flow & low ΔT and high flow & high ΔT, however, failed to outshine the rest of the inlet devices at low flow rate & low ΔT, and low flow rate & high ΔT. These research findings can serve as guidelines to optimize the storage tank design – more specifically, inlet device based design integrated with heating system, as thermal stratification and COP of heating system – heat pumps, for example, are inherently correlated. Heat pumps are high flow rate and low ΔT devices, while, solar systems are low flow rate and high ΔT devices, Thus, opting for accurate choice of inlet device for a particular operating condition is critical.

中文翻译：

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生活热水储罐分层性能的数值预测

摘要 一种有效的储存方式可以保持热分层并提高放电性能。冷热水之间的湍流混合是分层破坏的主要来源。在本文中，基于温度分布、MIX 数和理查森数实现了湍流缺失的量化。评估的参数包括流速、ΔT 和扩散器设计，因此在每个参数之间建立了直接的相互依赖关系。开发了各种 CFD 模型并在试验台上进行了实验验证，以找到放电模式下的最佳工作条件。The results proved numerically that the tank working conditions can be optimized by proper selection of inlet device. 例如，即使在湍流流入和低 ΔT 的不利条件下，开槽式入口装置也能保持最大的分层。穿孔和简单的入口装置仅在 200 l/h 的低流速下才能够提供最佳排放效率，并且对 ΔT 的依赖性很小。然而，随着流速的增加，ΔT 依赖性增加。看到开槽进气装置和降低 ΔT 的复合优势，得出的结论是，开槽进气装置在两种不利条件下（即高流量和低 ΔT 以及高流量和高 ΔT）都提供了相对更好的热性能，但是，未能超越其他条件低流速和低 ΔT 以及低流速和高 ΔT 的入口装置。这些研究结果可以作为优化储罐设计的指南——更具体地说，基于入口装置的设计与加热系统集成，因为加热系统的热分层和 COP，例如，热泵是内在相关的。热泵是高流量、低ΔT的装置，而太阳能系统是低流量、高ΔT的装置，因此，针对特定工况选择准确的进气装置至关重要。