化工学报
化工學報
화공학보
JOURNAL OF CHEMICAL INDUSY AND ENGINEERING (CHINA)
2014年
3期
890-897
,共8页
李永%茅靳丰%耿世彬%张华%韩旭
李永%茅靳豐%耿世彬%張華%韓旭
리영%모근봉%경세빈%장화%한욱
地埋管管群%动态负荷%土壤温度场%传热%模型
地埋管管群%動態負荷%土壤溫度場%傳熱%模型
지매관관군%동태부하%토양온도장%전열%모형
multi-boreholes%dynamic load%soil temperature field%heat transfer%model
对比分析了地埋管换热器的无限长线热源、有限长线热源和渗流有限长线热源模型,指出轴向传热和地下水渗流作用对地埋管换热具有不可忽略的影响;基于温度场叠加原理和动态负荷建立了地埋管管群换热模型,借助于典型年动态年负荷模型,分析了管群长期动态换热特性。结果表明,无渗流型管群中心温度升高过快,长期运行应考虑土壤换热能力的衰减;对于渗流型管群换热,应采取合理优化策略避免下游土壤温升过快,并且设计埋管时应采用其进入稳定期的换热能力,避免长期运行时换热能力不足。对3种日负荷动态运行模式下管群的典型点温度变化进行了对比分析,结果表明,运行模式调节可以减缓土壤温度的上升趋势,特别是可减少渗流型管群的下游热量堆积,有利于土壤换热能力的恢复。
對比分析瞭地埋管換熱器的無限長線熱源、有限長線熱源和滲流有限長線熱源模型,指齣軸嚮傳熱和地下水滲流作用對地埋管換熱具有不可忽略的影響;基于溫度場疊加原理和動態負荷建立瞭地埋管管群換熱模型,藉助于典型年動態年負荷模型,分析瞭管群長期動態換熱特性。結果錶明,無滲流型管群中心溫度升高過快,長期運行應攷慮土壤換熱能力的衰減;對于滲流型管群換熱,應採取閤理優化策略避免下遊土壤溫升過快,併且設計埋管時應採用其進入穩定期的換熱能力,避免長期運行時換熱能力不足。對3種日負荷動態運行模式下管群的典型點溫度變化進行瞭對比分析,結果錶明,運行模式調節可以減緩土壤溫度的上升趨勢,特彆是可減少滲流型管群的下遊熱量堆積,有利于土壤換熱能力的恢複。
대비분석료지매관환열기적무한장선열원、유한장선열원화삼류유한장선열원모형,지출축향전열화지하수삼류작용대지매관환열구유불가홀략적영향;기우온도장첩가원리화동태부하건립료지매관관군환열모형,차조우전형년동태년부하모형,분석료관군장기동태환열특성。결과표명,무삼류형관군중심온도승고과쾌,장기운행응고필토양환열능력적쇠감;대우삼류형관군환열,응채취합리우화책략피면하유토양온승과쾌,병차설계매관시응채용기진입은정기적환열능력,피면장기운행시환열능력불족。대3충일부하동태운행모식하관군적전형점온도변화진행료대비분석,결과표명,운행모식조절가이감완토양온도적상승추세,특별시가감소삼류형관군적하유열량퇴적,유리우토양환열능력적회복。
The comparison of the infinite line source model, finite line source model (FLS) and moving finite line source model (MFLS) of borehole heat exchangers (BHEs) shows that the axial effects and groundwater flow have some effects on BHEs. Based on the temperature superposition principle and dynamic loads, the heat transfer models for multi-boreholes are established, combined with typical annual dynamic load model, the long-term multi-borehole heat transfer is analyzed with FLS and MFLS. The results show that the center temperature of BHEs fields calculated with FLS increases fast and heat exchanger capacity attenuation should be taken into account for a long-term running. With MFLS, reasonable optimization strategy should be used to avoid fast increase of downstream soil temperature, and stable heat transfer ability should be adopted for design to prevent inadequate capacity of late runtime. The temperature rise at typical points in BHEs filed with three-day dynamic loads shows that the operation adjustment could significantly alleviate soil temperature rise and especially reduce the heat accumulation in downstream tubes, which is very good for recovery of soil heat exchanger capacity.