中文摘要：

为了提高相变蓄冷装置的换热性能以及蓄存的冷量品位，设计了一种梯级相变蓄冷换热器．基于焓法对该换热器建立数学模型，通过实验验证了该模型的可行性，并且对其换热过程进行了模拟仿真．根据其换热特性，以蓄冷时间及冷量焖效率为指标，对该换热器进行了优化分析．结果表明，在7℃进水，平均流速为1mm／s工况下，相变温度为12．3、13．0和13．3℃的3种相变材料按照1：1：1的组分比排列时，该换热器性能最佳．其炯效率为72．2％，蓄冷完成时间为160．4min；与相变温度为13．0℃的单一相变蓄冷器相比，炯效率和蓄冷速率分别提高了1．2％和1．7％．

英文摘要：

To improve the heat transfer performance and the energy quality of cold storage devices, a cascade phase change cold storage heat exchanger was designed. A mathematical model for the heat exchanger was developed based on the enthalpy method to simulate its heat transfer process, and the model was validated by experimental results. Furthermore, an optimization analysis of the heat exchanger was made according to such indicators as charge time and cold exergy efficiency, under an operating condition of 7 ℃ inlet water at an average speed of 1 mm/s. The results show that the heat exchanger has the best performance when three types of phase change materials, with phase change temperature combination of 12.3 ℃, 13℃and 13.3 ℃, are arranged by a mass ratio of 1：1：1. Under this condition, its exergy efficiency is 72. 2% and its charge time is 160.4min, which means the exergy efficiency and cold storage rate increase by 1. 2 % and 1.7 % compared with the single phase change cold storage device with a phase change temperature of13 ℃.