土壤蓄熱-放熱過程中地埋管周圍土壤溫度特性模擬
發(fā)布時(shí)間：2018-10-17 10:22
【摘要】：為探索內(nèi)蒙中部地區(qū)地源熱泵蓄熱-放熱過程中地埋管周圍土壤溫度變化特性,以垂直U型地埋管周圍土壤為研究對象,基于有限元分析法建立了二維非穩(wěn)態(tài)傳熱物理數(shù)學(xué)模型。在與試驗(yàn)結(jié)果進(jìn)行驗(yàn)證的基礎(chǔ)上,對土壤蓄熱、放熱和蓄熱-放熱耦合過程進(jìn)行模擬研究。分析了熱作用半徑、單位管長換熱量和土壤溫度隨熱泵運(yùn)行時(shí)間及運(yùn)行模式的變化規(guī)律;單一條件下的蓄熱、放熱以及蓄熱-放熱耦合模式下土壤熱平衡問題,探討了流體入口流速、溫度、土壤類型和熱泵運(yùn)行模式等因素對土壤溫度場的影響。研究結(jié)果表明:熱作用半徑隨蓄熱時(shí)間的增加而增大且逐漸趨于平緩,熱泵運(yùn)行25和28 d后,熱作用半徑分別為3.3和3.4 m;流體入口溫度對熱作用半徑及單位管長換熱量影響較大但流體流速影響較小,流體入口溫度和速度分別為40、60℃和0.6、1.2 m/s時(shí),對應(yīng)熱作用半徑分別為3.7、4.5和3.5、3.6 m。合理的間歇運(yùn)行模式對換熱量及埋管周圍土壤溫度的恢復(fù)均有改善;土壤導(dǎo)熱系數(shù)越大土壤溫度恢復(fù)時(shí)間與效果越佳,土壤導(dǎo)熱系數(shù)為3.1 W/(m?K)時(shí)恢復(fù)后溫度為9.3℃(土壤初溫9.5℃)。此外,蓄熱-放熱耦合模式下?lián)Q熱量不等對土壤熱平衡具有較大影響。試驗(yàn)驗(yàn)證表明,所建模型具有一定的準(zhǔn)確性其相對最大誤差為5.35%。
[Abstract]:In order to study the soil temperature change around the buried pipe in the process of heat storage and heat release of ground-source heat pump in the central part of Inner Mongolia, the soil around the vertical U-type buried pipe is taken as the research object. Based on finite element analysis, a two-dimensional unsteady heat transfer physical mathematical model is established. Based on the experimental results, the soil heat storage, heat release and heat storage coupled with heat release were simulated. The variation law of heat action radius, heat transfer per unit tube length and soil temperature with heat pump operation time and operation mode are analyzed, and the heat storage, heat release and soil heat balance under a single condition are analyzed. The effects of fluid inlet velocity, temperature, soil type and heat pump operating mode on the soil temperature field are discussed. The results show that the heat action radius increases with the increase of heat storage time and tends to be gentle. After 25 and 28 days of heat pump operation, The thermal action radius is 3.3 and 3.4 m.The fluid inlet temperature has great influence on the thermal action radius and heat transfer rate per unit tube length, but the influence of fluid flow velocity is small. When the fluid inlet temperature and velocity are 40 ~ 60 鈩，
本文編號：2276352
[Abstract]:In order to study the soil temperature change around the buried pipe in the process of heat storage and heat release of ground-source heat pump in the central part of Inner Mongolia, the soil around the vertical U-type buried pipe is taken as the research object. Based on finite element analysis, a two-dimensional unsteady heat transfer physical mathematical model is established. Based on the experimental results, the soil heat storage, heat release and heat storage coupled with heat release were simulated. The variation law of heat action radius, heat transfer per unit tube length and soil temperature with heat pump operation time and operation mode are analyzed, and the heat storage, heat release and soil heat balance under a single condition are analyzed. The effects of fluid inlet velocity, temperature, soil type and heat pump operating mode on the soil temperature field are discussed. The results show that the heat action radius increases with the increase of heat storage time and tends to be gentle. After 25 and 28 days of heat pump operation, The thermal action radius is 3.3 and 3.4 m.The fluid inlet temperature has great influence on the thermal action radius and heat transfer rate per unit tube length, but the influence of fluid flow velocity is small. When the fluid inlet temperature and velocity are 40 ~ 60 鈩，
本文編號：2276352
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