摘要
为了研究地埋管换热器在变负荷下连续运行与间歇运行的换热性能,基于有限长线热源渗流模型建立竖直地埋管钻孔外准三维非稳态传热模型,应用叠加原理计算钻孔群中钻孔壁温度场及地埋管内流体温度场。在存在地下水水平渗流的情况下,研究了变负荷连续运行模式下不同渗流速度、不同运行工况及不同钻孔位置对地埋管换热器的换热性能的影响。结果表明,在连续运行模式下,边缘位置的钻孔及较大的渗流速度能够增强地埋管换热器的换热性能;在间歇运行模式下,地埋管换热器的运行份额越小,其制冷效果越好,反之,制冷效果越差;在间歇运行工况下,土壤温度能在系统间歇期内得到一定程度的恢复,从而更好地提高地热能的利用率。
In order to investigate heat transfer performance of ground heat exchangers in continuous and intermittent operation mode under condition of dynamic load, a quasi-three-dimensional transient heat transfer model for borehole exterior of vertical ground exchanger is built based on finite line heat source groundwater advection model; The superposition principle is used to calculate borehole wall temperature field and temperature field of fluid in buried pipe among the boreholes. While groundwater is flowing in horizontal direction, the heat transfer performances of vertical ground heat exchangers are mainly studied at different seepage velocity, different operational states and different positions of borehole in continuous operation mode under dynamic load. The results show that the heat transfer performance, under the condition that boreholes are at the edge or the seepage velocity is high, may be enhanced in continuous running; and at low proportion of operation time of ground heat exchangers in the intermittent operation mode,cooling effect is better,whereas theirs cooling effect is worse. Temperature of the soil gets recovery in certain degree in the intermittent operation process, which improves preferably the efficiency of geothermal energy when ground heat exchangers is in intermittent operation condition.
出处
《可再生能源》
CAS
北大核心
2014年第11期1687-1693,共7页
Renewable Energy Resources
基金
"973"前期研究专项(2010CB434810)
广西矿冶与环境科学实验中心重点项目(KH2013ZD005)
关键词
地源热泵
地埋管换热器
动态负荷
间歇运行
换热性能
ground source heat pump
ground heat exchangers
dynamic load
intermittent oper-ation
heat exchange performance
