土壤源热泵间歇运行条件下土壤换热特性分析

Analysis on Soil Heat Transfer Characteristics of Ground Source Heat Pump under Intermittent Operation

为了研究间歇运行对竖直U型地埋管周围土壤温度的影响,通过实验研究分析了在夏季间歇运行模式下单U埋管和双U埋管土壤温度及单位管长换热量随系统运行时间的变化情况,探究了启停比对单位管长换热量以及对土壤温度恢复的影响。结果表明:系统在连续运行12 h后,地埋管周围土壤温度基本稳定,土壤温度上升的主要区段集中于开机后的0~6 h;在开停时间比为2 h∶2 h;3 h∶2 h;4 h∶2 h的工况下,单双U管的管长换热量与连续运行工况下对比都有所提高,并在实验中双U管的土壤温度恢复速率和土壤平均温度恢复比均高于单U管。

To explore the influence of intermittent operation on soil temperature around vertical U-tube buried pipe,through the experimental,the single U buried pipe and double U buried pipe soil temperature and the change of heat transfer per unit pipes length of the system running time are analyzed,and the effects of start-stop ratio on heat exchange per unit pipe length and soil temperature recovery in the summer intermittent operation mode is investigated.The test results show that after 12 hours of continuous operation of the system,the soil temperature around the buried pipe is stable,and the main section of the soil temperature rise is concentrated on 0-6 h after the start-up.When the start-stop time ratio is 2 h:2 h,3 h:2 h and 4 h:2 h.The heat exchange rate of tube length of single and double U tubes was improved,compared with that under continuous operation conditions.The soil temperature recovery rate and average temperature recovery ratio of double U tube are higher than those of single U tube in the experiment.