| Abstract |
Experimental apparatus containing circular disks of Geysers core (graywacke), highly porous sandstone, and non-porous aluminum were used to investigate and compare the temperature gradients that develop during boiling with liquid injection into a radial fracture. These experiments were designed to quantify the heat flux associated with water flashing to steam in a fracture, and to investigate the degree of coupling between the heat flux, flow rate, and the vapor fraction in the fracture. A preliminary comparison of data from experiments with porous and nonporous materials indicates that while heat transfer on nonporous surfaces is strongly coupled to the flow regime and vapor fraction, the heat flux to porous rock surfaces appears to be much less sensitive to the flow regime and vapor fraction. The magnitude of boiling heat fluxes and temperature gradients for Geysers graywacke, sandstone, and non-porous aluminum are compared and discussed. |