A device and method for recovering heat from the soil and groundwater, comprise heat-exchanging means consisting of an inner tube, an outer tube and partitions forming longitudinal channels between said inner and outer tube. An inlet for heat-exchanging fluid and an outlet for heat-exchanging fluid are present for conveying a heat-exchanging fluid through said longitudinal channels. The heat-exchanging means are preferably placed in a perforated casing allowing passage of liquid but not of soil particles. The casing consists preferably of an outer casing tube and an inner casing tube, casing partitions providing longitudinal casing channels. For allowing passage of groundwater the outer casing tube and the inner casing tube are provided with perforations. Heat is recovered by passing a heat-exchanging fluid through the casing channels.
A new and unique underground heat exchanging apparatus of the type including a first heat insulating tube and a second heat exchangeable tube connected to the former at the lower end of the latter. Both the first and second tubes are inserted downwardly into a deep hole drilled in the ground. The apparatus is operated by utilizing the excellent heat conservation and the huge heat capacity inherent to the underground. The first tube is located at the center of the hole and the second tube extends about the first tube in a spiral configuration. A liquified gas is introduced into both the first and second tubes. Heat exchanging is achieved between the second tube and the surrounding underground. To recirculate the liquified gas through the tubing system a heat exchanging unit including compressor and an expansion valve or the like is mounted on the ground surface. When the apparatus is used in a heating cycle, thermal energy is transferred from the underground to the second tube. On the other hand, when the apparatus is in a cooling system, heat is transferred from the second tube to the underground.
An arrangement for effecting an energy exchange between earth soil and an energy exchanger, and including a soil heat exchanger, and supply and return flow conduits for connecting the soil heat exchanger with the energy heat exchanger, with the soil heat exchanger having a thermoinsulated supply pipe arranged in a borehole formed in ground, a pump provided at an end of the flow duct, a shroud pipe surrounding the flow duct and the pump and having a section with a reduced inner cross-sectional area located beneath the pump and provided with a plurality of lateral inlet openings, and a return flow region for return water located radially outwardly of the shroud pipe and including return flow pipe means, connectable with the return flow conduit, and a porous filling, the return flow region communicating, in the vicinity of a borehole bottom, with an interior of the shroud pipe through the lateral inlet openings provided in the shroud pipe section with a reduced inner cross-sectional area.
A soil heat exchanger for effecting an energy exchange between earth soil and an energy exchanger and including a thermoinsulated flow duct arranged in a borehole formed in ground, a pump provided at an end of the flow duct, a shroud pipe surrounding the flow duct and the pump, and a return flow region for return water located radially outwardly of the shroud pipe and including return flow pipes and a porous filling, with the return flow pipe means extending down to a bottom of the borehole and having lateral opening means communicating with an interior of the shroud pipe through the inlet openings of the shroud pipe, with the shroud pipe having its lower end spaced from the bottom of the borehole, and with the lateral openings of the return flow pipes being beneath the lower end of the shroud pipe, and with the porous filling extending from the borehole bottom and at least up to a level above the inlet openings of the shroud pipe.
Process and equipment serving for the utilization of geothermic energy. In the course of the process water is introduced in a vapor producing pipe driven into the rock under the terrain and by making use of the geothermic heat, water is evaporated and the vapor is utilized such as for the generation of electrical energy. A superatmospheric pressure is set in the vapor producing pipe and a liquid (heat carrying medium) is let to trickle down in the tube, the saturated vapor of which contains 1000 kJ/m.sup.3 of latent heat of evaporation at the adjusted superatmospheric pressure. The equipment includes a vapor producing pipe embedded in the rock under the terrain, a liquid feeding device connected to the upper end of the vapor producing pipe as well as a device to serve for transforming the energy of the extracted vapor. The liquid feeding device comprises a distribution vessel, in which there is an annular spillway directing the liquid in a film-like layer on the inner surface of the vapor producing pipe and enclosing the opening of the distribution vessel ending in the vapor producing pipe.
Disclosed are a device and a method for utilizing the thermal energy in the soil to protect against damage to plants, such as citrus trees, from cold weather and to promote the growth of plants. The device comprises a heat pipe having an evaporator section which extends into the soil in the vicinity of the root system of the plants and extracts heat from the soil. The heat is then transferred to a condenser section which extends above ground and radiates and convects the heat to the plant. This also refrigerates the root system of the plant to extend the dormancy period. Also disclosed is a method for providing a supply of water to a plant, comprising the use of a heat pipe to create a temperature gradient around the root system of the plant, whereby water from the surrounding soil is caused to flow toward the plant.
