JP2003302107A - Geothermal heat exchange apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a geothermal heat exchange apparatus capable of efficiently collecting geothermal power. <P>SOLUTION: A heat exchanger 1 for collecting geothermal power by heat exchange is vertically laid underground. The geothermal power collected by the heat exchanger 1 is transferred to a radiating pipe 2 through a circulating path 3 and is emitted from the radiating pipe 2 for snow melting or the like. In this apparatus, the circulating path 3 is provided with two heating medium circulating pumps 4 one of which is a backup, an expansion tank 5 for absorbing a volume change of the heating medium, and a pressure detector 6 for detecting a pressure lower limit due to leakage of the heating medium or the like and stopping the circulating pumps 4. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can carry out snow melting, air conditioning, hot water supply, a heated pool, plant cultivation, animal breeding, etc., by using ground heat. It relates to an underground heat exchange device. Conventionally, it has been considered to pump groundwater (hot water) and use it for snowmelt, air conditioning, hot water supply, hot water pool, plant cultivation or animal breeding, etc. And cause land subsidence,
It is rarely implemented at present. In recent years, a heat exchanger for extracting geothermal heat has been buried underground, and a heat medium has been sent to the heat exchanger to indirectly exchange heat with the ground heat, thereby obtaining the collected heat. A device that melts snow and the like by using a device has been considered. [0004] However, there is a point to be improved in this conventional device, and there is no device that can extract geothermal heat efficiently enough so far. [0005] The present invention has been made in view of the above points, and it is an object of the present invention to provide an underground heat exchange device capable of efficiently extracting underground heat. A description will be given with reference to FIGS. 1 to 3. The underground heat exchange device according to the present invention embeds a heat exchanger 1 that extracts underground heat by heat exchange vertically underground, and transfers the underground heat collected by the heat exchanger 1 through a circulation path 3. In the underground heat exchange device which sends the heat to the heat radiating pipe 2 and releases the heat from the heat radiating pipe 2 to melt snow or the like, the circulation path 3 includes two heat medium circulation pumps 4 having And a pressure detector 6 that detects the lower limit of pressure due to heat medium leakage or the like and stops the circulating pump 4. FIG. 1 and FIG. 2 show an embodiment of an underground heat exchange device according to the present invention. This apparatus has a concentric double pipe type in which an inner pipe 1b is inserted and assembled concentrically in an outer pipe 1a whose lower end is closed, and a gap 1c is formed between the outer pipe 1a and the inner pipe 1b. The heat exchanger 1 is buried vertically in the ground. Then, a heat medium (antifreeze) is sent from the upper end of the inner cylinder, is inverted at the lower end, enters the gap 1c, and is raised to collect ground heat. Subsequently, the underground heat is sent to the heat radiating pipe 2 provided directly below the road surface via the circulation path 3 and is released by the heat radiating pipe 2 to melt snow. In the apparatus having such a configuration, two heat medium circulating pumps 4 having one spare are further provided in the circulation path 3.
And an expansion tank 5 for absorbing a change in the volume of the heat medium, and a pressure detector 6 for detecting the lower limit of pressure due to leakage of the heat medium and stopping the circulation pump 4. The heat exchanger 1 according to the present embodiment has an underground 5
A plurality of them are buried at a depth of 0 m to 100 m, and are spaced at least 5 m in order to avoid mutual thermal interference. The outer tube 1a is made of hard polyethylene having a diameter of 90 mm, and the inner tube 1b is also made of hard polyethylene having a diameter of 56 mm, and feeds a liquid medium at a rate of 20 to 25 liters per minute. The heat radiating pipe 2 is composed of a plurality of heat radiating tubes 2,
And each is bent into a hairpin curve shape and buried immediately below the road surface. The heat medium circulation path 3 has a forward path 3a and a return path 3b, and a heat medium circulation pump 4 is provided in the forward path 3a. This heat medium circulation pump 4 is provided with two units in parallel with respect to four to six heat exchangers 1, and one of them is used as a spare. Since one unit is used as a spare, even if the heat medium circulating pump 4 that is normally driven fails, by driving the spare, the present apparatus can be continuously operated without stopping. In addition, a flow meter 7,
An air vent valve 8, a relief valve 9, a pressure gauge 10, an expansion tank 5, and a pressure detector 6 are provided. The flow meter 7 measures the flow rate of the circulating heat medium, and the pressure gauge 10 measures the pressure in the heat medium circulation path 3. The expansion tank 5 absorbs a change in volume of the heat medium in the heat medium circulation path 3 due to a change in temperature. Further, the pressure detector 6 serves to stop the heat medium circulation pump 4 by issuing a signal when the pressure of the heat medium reaches the lower limit value due to damage of the heat medium circulation path 3 or the like. The operation of the underground heat exchange device will be described. First, when the heat medium circulation pump 4 is driven, the heat medium is supplied to the upper end of the inner pipe 1 b of the heat exchanger 1 through the outward path 3 a of the heat medium circulation path 3. After the heat medium travels downward in the inner cylinder, the heat medium reverses at the lower end thereof, enters the gap 1c, and is sent upward as it is. While passing through the gap 1c, the underground heat is collected by heat exchange. The heat medium from which the underground heat has been collected by the heat exchanger 1 passes through the return path 3b of the heat medium circulation path 3 and is sent to the header 11, from which it is distributed to the heat radiation tubes 2. Then, the underground heat is released from each of the heat radiating tubes 2, and the heat melts the snow on the road surface. During this time, when the volume of the heat medium changes due to a temperature change, the change in volume is absorbed by the expansion tank 5 and the heat medium is smoothly circulated. When the heat medium leaks and its pressure reaches the lower limit, a signal to that effect is transmitted and the heat medium circulation pump 4 is stopped to prevent the heat medium from leaking further. The heat radiating tube 2 is not limited to the concentric double tube type, but may be a U-shaped type shown in FIG. In this method, the center of the pipe main body 1d is divided by a partition wall 1e, and the liquid medium is fed from one passage and discharged from the other passage. The circulating pump 4 includes a commercial power source,
It can be operated by a solar thermal power generator or an internal combustion engine power generator. As shown in FIG. 4, the solar power generation device absorbs sunlight with a solar panel 12 and
The control board 1 that operates when charging is required is stored in the storage battery 15 in
The electric power is stored through the controller 4 and the controller 16 supplies a required amount of electric power to the circulation pump 4. The underground heat exchanger 1 according to the present invention is provided with two heat medium circulating pumps 4 and one of them is used as a spare. Even if 4 fails, the apparatus can be operated without stopping. Therefore, underground heat can be efficiently collected and snow melting can be performed effectively. Further, since the expansion tank 5 is provided, when the volume of the heat medium changes due to a change in temperature, the change in the volume can be absorbed. Medium heat can be efficiently collected. Furthermore, since the pressure detector 6 is provided, when the heat medium leaks, when the pressure reaches the lower limit, a signal to that effect is issued and the heat medium circulation pump 4 is stopped. Therefore, further leakage of the heat medium can be prevented, and ground heat can be efficiently collected. Since the present invention utilizes underground heat, no land subsidence occurs. In addition, geothermal heat exists indefinitely in the ground and is harmless. It does not induce environmental problems such as

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing an embodiment of the present invention. FIGS. 2A and 2B show a heat exchanger in the embodiment shown in FIG. 1, wherein FIG. 2A is a front sectional view and FIG. 3A and 3B show a heat exchanger according to another embodiment of the present invention, wherein FIG. 3A is a front sectional view and FIG. 3B is a plan sectional view. FIG. 4 is a flowchart of a solar thermal power generation device that operates a circulation pump of the device according to the present invention. [Description of Signs] 1 Heat exchanger 1a Outer pipe 1b Inner pipe 1c Gap path 1d Pipe main body 1e Partition wall 2 Heat radiating pipe 3 Circulation path 3a Outbound path 3b Inbound path 4 Heat medium circulation pump 5 Expansion tank 6 Pressure detector 7 Flow meter 8 Air Extraction valve 9 Release valve 10 Pressure gauge 11 Header 12 Solar panel 13 Battery box 14 Control board 15 Battery 16 Controller

[Procedure amendment] [Date of submission] February 24, 2003 (2003.2.2
4) [Procedure amendment 1] [Document name to be amended] Description [Item name to be amended] 0013 [Correction method] Change [Contents of amendment] The operation of this underground heat exchanger will be described. First, when the heat medium circulation pump 4 is driven, the heat medium is supplied to the upper end of the inner pipe 1 b of the heat exchanger 1 through the outward path 3 a of the heat medium circulation path 3. This heat medium, after traveling down the inner tube 1b , is inverted at the lower end and enters the gap 1c, and is sent upward as it is. While passing through this gap 1c,
Geothermal heat is collected by heat exchange. [Procedure amendment 2] [Document name to be amended] Drawing [Item name to be amended] Fig. 1 [Correction method] Change [Content of amendment] [Fig. 1]

Claims (1)

Claims 1. A heat exchanger (1) for extracting geothermal heat with a heat medium circulating in the inside thereof is vertically buried in the ground, and the ground sampled by the heat exchanger (1). An underground heat exchange device that sends medium heat to a heat radiating pipe (2) through a circulation path (3) and discharges the heat by the heat radiating pipe (2) to melt snow or the like. Two heat medium circulating pumps (4), which are used as spares, an expansion tank (5) for absorbing a change in the volume of the heat medium, and a circulating pump (4) for detecting a pressure lower limit value due to heat medium leakage or the like. Underground heat exchange device provided with a pressure detector (6) for stopping the operation.