An experimental and numerical study was carried out to investigate matrix-fracture thermal transport in fractured rock. Two different synthetically fractured core plugs were used during the flow-through experiments while core plugs’ outer surface was maintained at two different constant temperatures. To investigate the matrix-fracture thermal transport, cold water was injected through the single fracture core plugs at different flow rates. A film type heat flux sensor was used in the fractured core plug to measure the fracture temperature and heat flux over the matrix-fracture interface. Experimental results showed that fracture temperature decreases with increasing flow rate while heat flux increases. At high flow rates, temperature difference over matrix-fracture interface increases due to large volume of water contacting the fracture at a given time. Water temperature decreased more in the case of fracture surrounded by rock matrix with low volumetric heat capacity and thermal conductivity. A numerical model calibrated using experimental values of the fracture temperature was developed to estimate thermal properties of rock matrix and to identify their importance on the matrix-fracture thermal transport. Using the calibrated numerical model, it has been shown that temperature in the fracture and fracture surface temperature are different contrary to previous studies assuming the same values for these two temperatures. Local and transient convective heat transfer coefficients were introduced with respect to local values of temperature difference and transient values of heat flux along matrix- fracture interface enabling accurate representation of matrix-fracture thermal transport.

进行了实验和数值研究，以研究裂隙岩中基体-裂隙的热传递。在流通实验中使用了两个不同的合成断裂型芯塞，而芯塞的外表面则保持在两个不同的恒定温度下。为了研究基质-裂缝的热传输，冷水以不同的流速通过单个裂缝岩心塞注入。在破裂的芯塞中使用薄膜型热通量传感器，以测量基体-断裂界面上的断裂温度和热通量。实验结果表明，随着流速的增加，断裂温度降低，而热通量增加。在高流量下 由于大量水在给定时间接触裂缝，因此基质-裂缝界面上的温度差增加。如果裂缝被体积热容量和导热率低的岩石基质包围，则水温下降幅度更大。建立了使用断裂温度实验值校准的数值模型，以估计岩石基质的热学性质，并确定它们对基质-断裂热传导的重要性。使用校准的数值模型，已经表明，裂缝中的温度和裂缝表面温度与先前的研究相反，假设这两个温度的值相同。