地电场对裂隙岩块中对流传热特性影响的研究

STUDY ON EFFECT OF GEOELECTRIC FIELD ON CONVECTION HEAT TRANSFER PROPERTIES IN FRACTURED ROCK BLOCK

根据原地浸出过程中裂隙岩块中对流传热过程受地电场作用的特点,建立地电场作用下裂隙岩块中的对流传热模型,并通过电场作用下岩芯中的对流传热实验,研究地电场作用对裂隙岩块中溶液对流传热特性的影响。结果表明:地电场作用对裂隙岩块中对流传热的影响非常明显,其影响程度同热流密度、流体渗流速度以及流体性质等因素相关;对流换热系数总体上随正向电场电压升高而增强,随反向电场电压升高而降低;地电场作用下,低热流密度时对流换热系数的变化幅度明显高于高热流密度下换热系数幅度的变化;地电场作用对裂隙岩块中对流传热的影响随着溶液渗流速度的增加逐渐减弱;裂隙岩块中溶液矿化度越高,地电场对对流传热的影响越明显。

According to the properties that the convection heat transfer in fractured rock block is affected by geoelectric field in the process of in-situ leaching,the model of convection heat transfer under geoelectric field has been brought out;and the influences have been investigated through the experiments. The following results can be drawn. (1) The geoelectric field affects the properties of convection heat transfer obviously;and the influential degree is related with the heat flux,the seepage velocity of liquid,the characters of liquid and so on. (2) The convection heat transfer coefficient increases with the increase of forward electric field voltage,and decreases with the increase of the reversed one. (3) Under the action of geoelectric field,the variation amplitude of convection heat transfer coefficient with low heat flux is evidently higher than that with high heat flux. (4) The effect of the geoelectric field on the convection heat transfer in fractured rock block is weakened gradually with the increase of the seepage velocity of liquid. (5) The higher the mineralization of solution in fractured rock block is,the greater the influence of geoelectric field on the convection heat transfer is.