论文部分内容阅读
本文对超临界CO2在高度为0.2 mm的花岗岩平滑裂隙内的对流换热开展了实验研究,分析了岩心裂隙壁面温度、裂隙进出口流体温度、CO2从岩心吸收的净热量随时间的变化规律,并采用一定的数据处理方法得到花岗岩平滑裂隙充分发展段对流换热的努塞尔数.实验结果表明:CO2质量流量越大,裂隙壁面温度下降越快,流动方向上壁面温度相差越大,出口流体温度下降越快,能够从裂隙岩心带走的热量越多.超临界CO2通过高温花岗岩裂隙内层流充分发展段的Nu数基本上为一常数.“,”This paper presents experimental investigations of convection heat transfer of supercritical CO2 in a rock fracture with an aperture of 0.2 mm.The variation of rock wall temperature,fluid temperature and the overall heat extraction rate were analyzed.A data reduction method was proposed and validated.The Nusselt number for fully developed flow in the smooth rock fracture was obtained.The experimental results shows that at greater CO2 mass flow rate,the rate of temperature decrease at the rock wall increases and the differences among the wall temperatures along the flow direction increase.The CO2 temperature at the fracture outlet drops at a larger rate with larger mass flow rate,which indicates that supercritical CO2 with larger mass flow rate could extract more heat from the hot rock.The heat transfer coefficients were obtained by the data reduction method and it is shown that the Nusselt number is almost a constant for supercritical CO2 flowing in the rock fracture at the fully developed region.