矩形直肋地埋管换热器换热特性模拟分析

Simulation study on heat transfer characteristics of ground heat exchangers with radial rectangular fins

为强化地源热泵系统竖直地埋管换热器换热性能,设计了一种矩形直肋地埋管换热器,建立了矩形直肋地埋管换热器地下传热模型,利用Matlab软件模拟分析了直肋地埋管结构参数、运行参数对单U型和双U型地埋管换热器换热性能的影响。结果表明:当入口水温32℃,流速0.6 m/s,埋深100 m时,8片直肋单U型与双U型PE地埋管的单位埋深换热量与光滑管相比,分别提高了19.12%和18.28%。根据矩形直肋地埋管各参数与单位埋深换热量的相关性分析,肋片高度和肋片个数对换热性能的影响最为显著。

To enhance the heat exchange performance of vertical ground heat exchangers(GHE)for ground source heat pump system,a ground heat exchanger with radial rectangular fins was designed,and ground heat transfer model was established.Matlab software was utilized to simulate and analyze the effects of structure parameters and operation parameters of ground heat exchanger with radial rectangular fins on the thermal performance of single U-tube and double U-tube ground heat exchangers.The simulation results show that the heat exchange capacity per unit borehole depth of single-U and double-U PE tube with 8 fins is 19.12%and 18.28%higher than that of the smooth U-tube,under the condition of the inlet water temperature of 32℃,the flow rate of 0.6 m/s and the buried depth of 100 m.According to the correlation analysis between parameters and heat exchange capacity per unit borehole depth,the effect of fin height and number of fins on heat exchange performance are most significant.