METHOD OF SEASONAL USE OF LOW-POTENTIAL HEAT OF SURFACE SOIL, AND DOWNHOLE HEAT EXCHANGERS FOR IMPLEMENTATION OF METHOD'S VERSIONS Russian patent published in 2013 - IPC F24J3/08 F24D11/02 

FIELD: heating.

SUBSTANCE: when implementing the method during the heating period, low-potential heat is removed from soil. Supply of liquid heat carrier is performed through soil layers by means of the main closed circulating system with closed-type vertical loops installed by means of wells. Then, heat is transferred so that it is converted by means of a heat-pump cycle to a higher temperature level to the heat supply network of the power supply site. During the non-heating period, accumulation of external heat discharges in the soil is selected and supply of heat carrier through the soil layers is changed over to an additional closed circulating system with an intermediate heat exchanger for utilisation of heat discharges, which is installed into it. When changing over from heat removal to accumulation of heat discharges, depth of heat carrier supply is changed through the soil layers from intersection level of vertical loops of one or several water-bearing soil layers to the level above the roof of upper water-bearing layer. For that purpose, some part of the loops used for heat extraction from soil is used at heat extraction and accumulation of heat discharges as per a shortened version by installing those loops as a part of the additional circulating system with the length corresponding to the second of the above levels. The rest loops are installed as a part of the main circulating system with the length corresponding to the first level. When changing over from the soil heat extraction to accumulation of heat discharges, the method allows changing heat carrier supply depth through the soil layer from the intersection level of vertical loops as a part of the main circulating system of one or several water-bearing soil layers to the level above the roof of upper water-bearing layer, thus installing vertical loops in compliance with the last level as a part of the additional circulating system, the length of which is chosen as shortened relative to that one which is chosen in compliance with the first level of length of loops of the main circulating system. The task of the seasonal change of levels is solved either by using known structural designs with wells of various depths as a part of loops, or based on the proposed design of the downhole heat exchanger.

EFFECT: more effective seasonal change of levels.

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