Value of researches of a thermal stream. Hydrothermal konvektivnye systems

you are: Value of researches of a thermal stream

Liquid and steam geothermal systems are two basic types hydrothermal konvektivnyh systems. That resources possessed high entalpiej (teplosoderzhaniem), i.e. That the temperature of deposits exceeded 150 °s, within such systems following conditions should be satisfied.

1. On depth some thousand metres should be a large source of heat with are abnormal a heat. Apparently, long-living sources of heat of geothermal resources are dated for magmatic breeds with the high maintenance of silicon more often. The big viscosity of these breeds can support heats of converting systems during the long periods of time on depths from 2 to 10 km. Areas of prospective congestions of geothermal fields with high entalpiej are limited therefore to zones young (kajnozojskoj) volcanic activity. Suitable places young intruzy the magmas, being on small depth, are areas chetvertichnogo raisings and pozdnechetvertichnogo and tertiary lowering. These areas are characterised by regional anomalies of the high superficial thermal stream exceeding 80 мВт/м3, and higher values in locally limited areas.

2. The porous and nontight zones filled with water (vodonosnye horizons), should be included in hyperthermal sites of bowels, and the water temperature should be close to a boiling point or above it (the boiling point depends on pressure, i.e. From depth of the tank with water). In the tank meet konvektivnye streams of hot water (liquid systems) or pair (steam systems); hence, teploperenos within the tank it is carried out basically konvektivno, and the difference of temperatures between a sole and a roof of such tank is very small.

Breeds of the tank can be various litologicheskogo structure. In Uajrakee, New Zealand, they consist from pemzovidnoj brekchii and a tufa; in Matsukave, Japan, the tank it is formed treshchinovatymi by sedimentary breeds and dacitic lavas; around geothermal field Otake, Japan, breeds are presented treshchinovatymi andezitami; the tank in Larde-rello, Italy, is combined treshchinovatymi by limestones and dolomite. Borders of complexes of breeds and their disagreement can be also zones of formation of natural steam if they have high permeability and are filled by water. Nontight vodonosnye the horizons forming the tank, should be connected gidravlicheski with the big area of capture of superficial waters. Studying of isotope structure of geothermal fields specifies that the atmospheric origin has 95% of thermal fluids from steam chinks.

3. To a natural exit of hot fluids from the steam tank should stir blocking breeds with low permeability. It is impossible to avoid teplopoter from the tank owing to heat conductivity. However these teplopoteri, the substances caused by heat conductivity it is, much less, than the losses caused konvektsiej of heat from the tank to a day surface.