Value of researches of a thermal stream. Liquid geothermal deposits

you are: Value of researches of a thermal stream

Liquid geothermal deposits are formed in the event that there is a tank with breeds of high permeability in which water (or a brine circulates) and heat is transferred from a deep source. In such systems of temperature above 300 °s of 2000 m (hot brines of Salton Sea) are found out on depth. In Uajrakej, New Zealand, liquid geothermal system is used for electricity manufacture at capacity 140 MVt (in 1978) from the tank with the maximum temperature nearby 260 °s.

Heats of tanks (above a water boiling point on a surface) do not cause water evaporation as the weight of the water filling a time and cracks, increases pressure. At hydrostatic pressure the water boiling point makes: on depth of 100 m - 180 °s, 500 m - 265 °s, 1 km - 310 °s and 2 km - 365 °s. Any quantity of steam can be allocated in the form of bubbles, but the pressure gradient is supervised by density of liquid water and continuously increases with depth.

Konvektsija in nontight, filled with water more thickly than breeds grows out of thermal expansion of water. The greatest density, 1 g/sm3, water has at 4 °s, and it decreases to 0,958 at 100 °s, 0,863 at 200 °s and 0,715 at 300 °s. As shown in the previous section, konvektsija brings very big contribution to a total sum teploperenosa. In the top parts konvektivnoj cells over a geological source of heat of temperature above, than on the same depth, but there where konvektsija is absent. Within zones konvektsii temperature gradients are small.

In most cases systems geothermal konvektsii are systems of hot water. Large known liquid geothermal fields on which it is extracted warmly for manufacture of electric energy, is Uajrakej (New Zealand) - 170 MVt; Brodlends (New Zealand) and Serro-Prieto (Mexico) - 75 MVt; Salton Sea (California, the USA), Yellowstone (Wyoming, the USA) and Auachapan (El Salvador) - 60 MVt.