Evaluative Analysis of Formulas of Heat Transfer Coefficient of Rock Fracture

Improved test method for convection heat transfer characteristics of carbonate fractures after acidizing etching

“…These pores, caves, and micro-fractures caused by acid etching can increase the convection channel and increase the contact area with the heat transfer working medium, thereby increasing the heat production of geothermal reservoir (Ma et al, 2019). The special fracture morphology of carbonate is totally different from those of granite and sandstone in previous studies (Zhao et al, 1999;He et al, 2016;, Ma et al, 2018Jiang et al, 2020), and can increase the convection channel and increase the contact area with flowing fluid and results in the inapplicability of the hypothesis to carbonate fractures after acidizing etching.…”

“…Convection heat transfer coefficient is usually used to quantitatively describe the convection heat transfer process of fluid through the fracture surface under high temperature (Jiang et al, 2017;Luo et al, 2019). Different methods have been proposed to determine the convection heat transfer coefficient on different types of rock fracture by theoretical or laboratory approaches (Ma et al, 2018;Jiang et al, 2020). By calculating the average heat transfer coefficient between two disk walls, Ogino et al (1999) creatively proposed that the forced convection between water and the crack surface plays an essential role in the convection heat transfer process.…”

Numerical and Analytical Study of Fluid Flow and Thermal Transfer in a Rough Fracture

“…Fracture Models. In the past, the research on the flow and heat transfer characteristics of fracture fluid is mostly based on the single fracture cylinder model [10,26]1. In this paper, the physical model of flow and heat transfer is a twodimensional plane model with length (L) of 100 mm and width (2R) of 51 mm, which is formed from the plane intercepted from a cylindrical sample with a single fracture.…”