首页|Stratum temperature recovery considering groundwater advection in periodic operations of deep borehole heat exchangers
Stratum temperature recovery considering groundwater advection in periodic operations of deep borehole heat exchangers
扫码查看
点击上方二维码区域，可以放大扫码查看
原文链接
NSTL
Elsevier
During periodic operations of the deep borehole heat exchanger (DBHE), stratum temperature recovery is significantly affected by groundwater advection, but it has not been fully addressed. In this study, the stratum temperature recovery of long-term and periodic operations of DBHE is quantitatively analyzed via an improved analytical model developed in our previous work. To characterize its dependence on Darcy velocity, recovery rate, quasi-equilibrium time, and thermal impact scope are accordingly defined. Sensitivity analyses of thermal conductivity and thermal dispersion are also conducted. The results show that the recovery rate increases with Darcy velocity but varies slightly with heat extraction power inside the borehole. There is a critical Darcy velocity in periodic operations. When the groundwater advection velocity reaches the critical value, stratum temperature at the borehole wall gets close to its initial state after every recovery period, and multiple low-temperature valleys downstream of the groundwater advection occur. The greater thermal conductivity of medium and thermal dispersivity can result in the higher critical Darcy velocity. The thermal impact scope of the DBHE decreases overall when Darcy velocity increases, while the downstream thermal impact radius has a sharp increase for low Darcy velocities before the decline.
Critical Darcy velocityDeep borehole heat exchangersGroundwater advectionStratum temperature recovery
Jiao K.、Bai B.、Yang R.、Yu B.、Sun C.
展开 >
State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University
Shanxi Yanchang Petroleum International Exploration and Development Engineering Co. Ltd
School of Mechanical Engineering Beijing Key Laboratory of Pipeline Critical Technology and Equipment for Deepwater Oil & Gas Development Beijing Institute of Petrochemical Technology
NSTL
Elsevier
