| Title |
Experimental and Numerical Study on Stratification Characteristics of a Water-Based Thermal Energy Storage Tank under Different Charging Directions and Flow Rates |
| Authors |
Sunyoung Moon ; Yoong Chung ; Konghoon Lee ; Dongho Kim |
| DOI |
https://doi.org/10.6110/KJACR.2026.38.5.271 |
| Keywords |
성층화; 열에너지저장; 온도 구배; 물탱크 Stratification; Thermal Energy Storage; Thermocline; Water Tank |
| Abstract |
This study examines the thermal stratification characteristics of a water-based thermal energy storage (TES) tank under various charging directions and flow rate conditions. A lab-scale TES system was designed using Froude similarity, based on a prototype intended for integration with a 1000RT heat pump system. We conducted experiments and CFD simulations using a 2-D axisymmetric model (Ansys Fluent) to validate thermal behavior and assess stratification performance. Charging tests were performed for both top-to-bottom and bottom-to-top configurations at flow rates of 127 LPM and 215 LPM. The results indicated that top charging effectively maintained a distinct thermocline region, with a Richardson number up to five times higher than that of bottom charging, demonstrating stronger stratification. While increased flow rates accelerated charging, they also weakened stratification due to enhanced momentum effects. The discharging tests confirmed that the outlet temperature remained stable at 43℃ for the designed discharging duration before beginning to decrease. These findings underscore the importance of inlet design and flow control in enhancing TES tank performance and sustaining thermal stratification. |