A Study on the Natural Convection in the Opened Geothermal Reservoir (IV)

Effects of the length of impermeable portion at the top surface

Abstract

Theoretical and experimental studies are on effects of the length of impermeable portion at the top surface of the opened geothermal reservoir on a thermal convection. The reservoir is 9.2 in the reservoir aspect ratic and 2 in the heat source aspect ratio. The results obtained are as follows:(1) As the length of the impermeable portion increases, the value of stream function decreases and the convective current comes to be excel in a horizontal direction. So the convective current is influenced by the length of impermeable portion.(2) As the length of the impermeable portion increases, both temperatures within the reservoir and on the top surface rise further, which reflect the varation of the convective current mentioned above.(3) The discharge velocity of water through the top surface becomes maximum at the edge of the impermeable portion, and the discharge area of water is reflectively narrow.(4) The heat discharged through the top surface increases abruptly at the discharge area of water and the heat transported by water is above 10 times as large as the quantity transported by Newton's law of coling, and both discharges of water and heat per an unit time through the top surface decrease gradually as the length of the impermeable portion increases. These facts show that the discharged water plays an important role in a process of the discharge of heat.