Fig. 14From: An efficient hybrid model for thermal analysis of deep borehole heat exchangersVariation of thermal impacted radius and rock temperature near the boundary of thermal impacted radius (radial far field temperature of rock) on the basis of efficient modeling along depth with time during the heating season. a 5 days, b 20 days, c 40 days, d 60 days. The black and black dotted line denoting rock temperature refer to the left y-axis, while the red line denoting thermal impacted radius refers to the right y-axisBack to article page