The present study aims at investigating numerically the thermal performance of a shell-and-tube phase change material (PCM) storage system for district heating network (DHN). A transient thermal model, which is based on energy balances, is developed and validated with experimental data from a full-scale 180 kWh PCM storage installed in the DHN of Flaubert substation (France). The effect of several design and operation parameters such as the target thermal power by the DHN during the discharging process, the PCM type, the number of tubes in the storage unit and the water return temperature on the storage performance is presented and analyzed. The results show that the studied system, under specific conditions, can supply hot water to the DHN at a temperature equal to or higher than 70°C for a certain period. The thermal power released by the storage system can be kept constant during this period by regulating the flow rate of the water. This period is reduced by decreasing the number of tubes in the storage unit or increasing the value of the water return temperature. Finally, the choice of the melting temperature of the PCM is crucial to maximize the performance of the storage system.

本研究旨在数值研究用于区域供热网络 (DHN) 的管壳式相变材料 (PCM) 存储系统的热性能。基于能量平衡的瞬态热模型被开发并使用来自安装在 Flaubert 变电站（法国）DHN 中的全尺寸 180 kWh PCM 存储的实验数据进行验证。提出并分析了DHN在排放过程中的目标热功率、PCM类型、蓄热单元中的管数和回水温度等几个设计和运行参数对蓄热性能的影响。结果表明，所研究的系统在特定条件下，可以在一定时间内向DHN供应温度等于或高于70°C的热水。在此期间，通过调节水的流量，可以使蓄热系统释放的热功率保持恒定。通过减少存储单元中的管道数量或增加回水温度值来缩短此时间。最后，PCM 熔化温度的选择对于最大化存储系统的性能至关重要。