论文部分内容阅读
对于地埋管换热器,综合考虑传热性能和消耗的功率,建立管内流体的熵产模型。考虑两支管间热短路影响,确定流体沿管长的温度分布。以最小熵产为目标,根据沿埋管深度的温度分布,在不同换热负荷条件下,确定地埋管换热器的最优长度和管径随流量的变化关系,换热负荷确定时,埋管的最优管长随流量增加而减小,地埋管的最优管径随流量的增加而增大。在流量一定的条件下,埋管的最优管长随换热负荷的增加而增加,最优管径随换热负荷的增加也相应增大。以青岛市某实验室土壤源热泵系统为例,分析最优长度和管径对换热效能及系统性能的影响。
For the buried tube heat exchanger, the entropy generation model of the fluid in the tube is established considering the heat transfer performance and the consumed power. Consider the effect of thermal short circuit between two tubes and determine the temperature distribution of the fluid along the tube length. According to the temperature distribution along the depth of buried pipe, the optimal length of pipe heat exchanger and the change of pipe diameter with flow rate are determined under different heat transfer load. When the heat transfer load is determined, The optimal pipe length of buried pipe decreases with the increase of flow rate, and the optimal pipe diameter of buried pipe increases with the increase of flow rate. Under certain flow conditions, the optimal tube length increases with the increase of heat transfer load, and the optimal tube diameter increases with the increase of heat transfer load. Taking a laboratory ground source heat pump system in Qingdao as an example, the effects of optimal length and diameter on heat transfer performance and system performance are analyzed.