Measurement method of convective heat transfer coefficient of water-rock interface during seepage heat transfer of fractured samples

Abstract

The invention discloses a method for measuring convective heat transfer coefficient of a water-rock interface during a seepage heat transfer process of a crack sample. Constant-temperature and constant-current water flow is injected to a convective heat transfer coefficient test system through a liquid constant-voltage constant-current high-precision injection system and a cold drive hot water flow constant temperature control system; a convective heat transfer coefficient h of the water-rock interface is measured through the convective heat transfer coefficient test system; during measurement, variables related to the convective heat transfer coefficient, such as flow rate, inlet water temperature, crack initial gap length b0 and crack gap length deformation delta b, all can be set according to requirements of an experimenter; the test measurement variables such as outlet water flow rate Q, crack outlet water temperature Tout, crack inner edge water temperature Ff and crack inner surface temperature Ti all can be accurately measured; finally, the convective heat transfer coefficient h is obtained by calculating. According to the method for measuring convective heat transfer coefficient of a water-rock interface during a seepage heat transfer process of a crack sample in the invention, the variables are controlled more accurately; the numerical value of the convective heat transfer coefficient h in a certain state can be obtained through an improved calculation method; and the quantitative relationship between h and different variables can be researched.

Description

technical field [0001] The invention relates to a method for measuring and calculating the convective heat transfer coefficient, in particular to a method for measuring the convective heat transfer coefficient of the water-rock interface in the seepage heat transfer process of a fissure sample, and belongs to the field of mine geothermal and thermal damage prevention and control. Background technique [0002] With the deep mining in eastern my country and some central regions, high-temperature mines are becoming more and more common. In view of the high-heat abnormal mines caused by deep circulation rising groundwater, the active utilization or passive prevention of geothermal resources has become a new research direction for green mines. The key issues to be solved in this research topic include the research on the water-heat migration characteristics in the fracture network of rock mass, and the experimental research on the water-heat migration characteristics of a single f...

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Problems solved by technology

[0005] The above formula is a model of rock temperature field and fracture water temperature field in the single-fracture seepage-heat transfer process. In the above formula, domestic and foreign studies have accurately described heat conduction in rock mass, internal heat conduction and heat convection in the fluid, but for the water-rock interface There is a lack of systematic research on heat exchange. The convective heat transfer coefficient h (hereinafter referred to as h) determines the heat exchange between bedrock and fracture water. For the heat transfer of fracture systems, there is currently no suitable empirical formula or accurate formula for the value of h. theory, and very little experimentation

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