A model study for a geothermal hot-water reserve estimation has been made measuring the surface temperature distributions as functions of the depth, the temperature, and the size of the disk and rectangular shaped heat source. The dried soil and the cement powder were used as a medium.
The result of the experiment was compared with the computer solution to find a good agreement with each others.
Computer simulation for a geothermal system (depth : 200m, temp. : 100 ℃, granite) showed that temperature difference between geothermal area and other areas was no more than 0.2 ℃. In order to find the temperature difference of the earth higher than 4.5 ℃, temperature distribution at 5 meters below the surface should be obtained.
The depth, the temperature, and the size of the heat source could be estimated from the surface temperature distribution data by the following empirical equations.
d = 40.65 a + 13.98
$T_R = (ΔT)_{max} \exp (0.55 + 0.35 d)$
$b = 3.0 ×10^{-3}T_R - 0.27 d + 3.45$
