基于动态负荷的混合式制冷制热系统优化设计

传统的换热器设计方法忽视了混合式制冷制热系统系统的动态特性。采用一种新的U型土壤埋管换热器的变模型及相应的工程设计方法，能够更加科学准确地设计U型土壤埋管换热器。对不同时间尺度、不同空间区域的传热过程采用相对应的计算方法，利用虚拟热汇、格林函数法建立了有限长圆柱体热源模型，并给出了解析解，应用新方法对实例进行设计。结果表明，该系统30年的平均能效比COP(Coefficient of Perfomance)为4.73，可以长期、稳定、高效运行。

Optimal design of hybrid refrigeration and heating system based on dynamic load

The traditional design method ignores the dynamic characteristics of hybrid refrigeration and heating system.This paper adopted a new variable model of U-shaped soil heat exchanger and the corresponding engineering design method，and U-shaped soil heat exchanger can be designed more scientifically and accurately.The corresponding calculation method is used for the heat transfer process in different time scales and different space regions，and then the finite length cylinder heat source model was established by using virtual heat sink and Green′s function method，and the analytical solution was given.Finally，the example was designed by using the new method.The results showed that the average COP of the system is 4.73 in 30 years，which can achieve long-term stable and efficient operation.