JP2001004232A - Circulating geothermal heat utilizing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a heat transfer rate on an inner surface of a tubular wall of an outer tube with a bottom, to improve a heat exchange performance and to collect or radiate (thermally store) a large heat by generating a turbulence in a flow of an antifreeze solution (heating medium). SOLUTION: In the circulating geothermal heat utilizing apparatus, a tube axis C2 of an inner tube 4 with an open bottom is formed in a zigzag state obtained by continuing an eccentric portion eccentrically deviated in a direction opposite to a vertical tube axis C1 in one vertical plane passing an axis C1 of an outer tube 2 with a bottom and a concentric portion concentric with the axis C1, and a plurality of bent portions 10 formed in a zigzag manner in a direction of the axis C1 to the tube 4 are provided at an equal interval over the entire length. A flowing velocity of an antifreeze solution (heating medium) flowing through an annular gap 3 is changed by the plurality of the portions 10 so that a turbulence takes place in the flow of the solution. Thus, a heat transfer rate of the inner surface of the tube 2 with the bottom is enhanced to improve heat exchange performance, and a large heat can be collected or radiated (thermally stored).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to, for example, road snow melting equipment, air conditioning equipment or hot water supply equipment by collecting heat from soil in winter. The present invention relates to a circulating geothermal utilization device that collects and uses heat.

[0002]

2. Description of the Related Art As a circulation type geothermal utilization apparatus of this kind, there is provided an apparatus described in Japanese Patent No. 2700998. As shown in FIG. 7, this circulation type geothermal utilization apparatus has an open bottomed inner pipe 4 concentrically inserted into a bottomed outer pipe 2 buried in soil 1 with an annular gap 3 and a radial spacer. The circulating pump 8A that circulates an antifreeze (a heat medium) between the double pipe 6 and the heat pump 7, for example, by forming the double pipe 6 with the inner and outer pipes 2 and 4 that cannot be relatively displaced.
Heat exchanger 9 having a circulation system 8 composed of
By applying heat from the soil 1 in winter, for example, it is applied to road snow melting equipment, air conditioning equipment, hot water supply equipment, etc., and in summer, external heat is radiated to the soil (heat storage) to collect heat in winter and use it. Have been.

[0003]

However, in the conventional circulation type geothermal utilization apparatus, since the open bottomed inner pipe 4 is inserted concentrically with the bottomed outer pipe 2 having the vertical pipe axis C1, the antifreeze liquid is not removed. It flows in the annular gap 3 in the same direction as the pipe axis C1 at a constant flow velocity. For this reason, it cannot be said that the heat transfer coefficient on the inner surface of the tube wall of the bottomed outer tube 2 is high, and large heat collection or heat dissipation (heat storage) cannot be expected. That is, theoretically, the heat transfer coefficient on the inner wall surface of the bottomed outer tube 2 increases due to the disturbance of the flow of the antifreeze in the annular gap 3 or the increase in the flow rate of the antifreeze. Although it is experimentally proven, it does not have a function of disturbing the flow of antifreeze or a function of increasing the flow rate of antifreeze, so the heat transfer coefficient on the inner surface of the bottomed outer tube 2 is low, and the heat exchange performance is poor. Has disadvantages.

Therefore, the present invention improves the heat exchange performance by increasing the heat transfer coefficient on the inner surface of the bottomed outer tube by causing turbulence in the flow of the antifreeze or increasing the flow rate of the antifreeze. It is an object of the present invention to provide a circulating-type geothermal utilization device capable of performing large heat collection or heat radiation (heat storage).

[0005]

In order to achieve the above object, a circulating-type geothermal utilization apparatus according to the first aspect of the present invention is provided with an open bottomed outer pipe buried in soil having an annular gap. A heat exchanger equipped with a double pipe having a structure in which a bottom inner pipe is inserted, and a circulation system for circulating a heat medium through the double pipe is configured to collect heat from the soil or radiate heat to the soil. In the circulation type geothermal utilization apparatus, a bent portion meandering in a vertical pipe axis direction of the bottomed outer pipe is provided on at least a part of the open bottom inner pipe.

In order to achieve the object, a circulating-type geothermal utilization apparatus according to a second aspect of the present invention is configured such that an open bottomed inner pipe is inserted into a bottomed outer pipe buried in soil with an annular gap. Geothermal utilization device configured to collect heat from soil or radiate heat to soil by using a heat exchanger equipped with a double pipe having a structure described above and a circulation system for circulating a heat medium through the double pipe. In at least a part of the open bottomed inner pipe, the pipe axis of the open bottomed inner pipe is turned around a vertical pipe axis of the bottomed outer pipe and bent in a spiral shape extending in the vertical pipe axis direction. It is characterized by being constituted by a composed part.

According to the first aspect of the present invention, the flow rate of the heat medium flowing through the annular gap is formed by the bent portion of the bottomed outer tube provided on at least a part of the open bottomed inner tube meandering in the vertical tube axis direction. Is changed, and the flow of the heat medium is disturbed by the change in the flow velocity, so that the heat transfer coefficient on the inner wall surface of the bottomed outer tube can be increased.

According to the second aspect of the present invention, at least a part of the open-bottomed inner pipe is formed by the bent portion spirally bent, so that the heat medium flows through the annular gap by the bent portion. Is given a swirl component to the vertical flow component, and the vertical flow is converted into a swirl flow. Thus, the flow velocity of the actual swirling flow is made higher than the flow velocity of the vertical flow, and the heat transfer coefficient on the inner surface of the bottomed outer tube can be increased.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of the circulation type geothermal utilization apparatus according to the first aspect of the present invention, and FIGS. 2 (a) to 2 (d) are transverse sectional views of FIG.
The same or corresponding parts as those in the conventional example of FIG. 7 are denoted by the same reference numerals, and detailed description other than the bottomed outer tube and the open bottomed inner tube is omitted.

1 and 2 (a) to 2 (d), the pipe axis C2 of the open bottomed inner pipe 4 is changed to the vertical pipe axis C of the bottomed outer pipe 2.
Eccentric portions that are eccentric in opposite directions to the vertical tube axis C1 on one vertical plane F1 passing through {circle around 1} (see FIGS. 2A and 2C) and concentric portions concentric with the vertical tube axis C1 {FIG. (B) and FIG. 2 (d) are formed in a meandering shape that is continuous, so that the open-bottomed inner tube 4 is formed by bending a plurality of bent portions 10, 10 ... meandering in the direction of the vertical tube axis C1 over the entire length. The structure is provided at intervals. The open bottomed inner tube 4 is inserted into the bottomed outer tube 2 with an annular gap 3 and is provided with a spacer 5 in a radial direction so that the inner and outer tubes 2 and 4 cannot be displaced relative to each other. The heavy pipe 6 is constituted.

As described above, the open bottom inner tube 4 having the plurality of bent portions 10, 10... In which the tube axis C2 meanders in the direction of the vertical tube axis C1 is provided at regular intervals over the entire length. 3
., The flow rate of the antifreeze (heat medium) flowing through the annular gap 3 changes due to the plurality of bent portions 10, 10 meandering in the direction of the vertical pipe axis C1, and the antifreeze is The flow of air is disturbed. For this reason, the heat transfer coefficient on the inner surface of the tube wall of the bottomed outer tube 2 can be increased, the heat exchange performance can be improved, and large heat collection or heat radiation (heat storage) can be performed.

The invention described in claim 1 is not limited to the embodiment shown in FIGS. That is, in the above embodiment, the plurality of bent portions 1 meandering in the direction of the vertical pipe axis C1 over the entire length of the open bottom inner pipe 4.
Are provided at regular intervals, but a plurality of bent portions 1 are provided.
.. May be provided at unequal intervals. Further, a bent portion 10 meandering in the direction of the vertical tube axis C1 may be provided in a part of the open bottom inner tube 4. As described above, the bent portion 1
In the structure where 0 is provided, as shown in FIG. 3, it is advantageous in terms of heat exchange performance to provide the bent portion 10 at a deep portion of the open-bottomed inner tube 4 having a large difference in heat collection or heat release temperature.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a cross-sectional view showing one embodiment of the circulation type geothermal utilization apparatus according to the second aspect of the present invention, and FIGS. 5 (e) to 5 (h) are cross-sectional views of FIG. The same or corresponding parts as those in the conventional example of FIG. 7 are denoted by the same reference numerals, and detailed description other than the bottomed outer tube and the open bottomed inner tube is omitted.

In FIG. 4 and FIGS. 5 (e) to 5 (h), the open bottomed inner tube 4 spirals its tube axis C2 around the vertical tube axis C1 of the bottomed outer tube 2 over its entire length. Thereby, it is constituted by the bent part 11 bent in a spiral shape. The open bottomed inner tube 4 is inserted into the bottomed outer tube 2 with an annular gap 3 and is provided with a spacer 5 in a radial direction so that the inner and outer tubes 2 and 4 cannot be displaced relative to each other. The heavy pipe 6 is constituted.

As described above, by turning the pipe axis C2 in a spiral around the vertical pipe axis C1 of the bottomed outer pipe 2, the open bottom formed by the bent portion 11 whose entire length is spirally bent. When the inner pipe 4 is inserted into the bottomed outer pipe 2 with the annular gap 3, the antifreeze (heat medium) flowing through the annular gap 3
Is given a swirl component to the vertical flow component, and the vertical flow is converted into a swirl flow. Thereby, the flow velocity of the actual swirling flow is made higher than the flow velocity of the vertical flow,
The heat transfer coefficient on the inner surface of the tube wall of the bottomed outer tube 2 can be increased.

The invention described in claim 2 is not limited only to the embodiment shown in FIGS. That is, in the above-described embodiment, the entire length of the open-bottomed inner tube 4 is constituted by the bent portion 11 which is bent in a spiral shape. It may be constituted by the unit 11. As described above, in the open-bottomed inner tube 4 partially constituted by the bent portion 11 bent in a spiral shape, as shown in FIG. It is advantageous in terms of heat exchange performance to locate the bent portion 11 at a deep portion.

[0017]

As described above, the circulating geothermal utilization apparatus according to the first aspect of the present invention has a bent portion meandering in the vertical tube axis direction of the bottomed outer tube on at least a part of the open bottomed inner tube. Is provided, the flow rate of the antifreeze (heat medium) flowing through the annular gap is changed, and the flow of the antifreeze can be disturbed by the change in the flow rate. Therefore, the heat transfer coefficient of the bottomed outer tube on the inner surface of the tube wall can be increased, the heat exchange performance can be improved, and large heat collection or heat dissipation (heat storage) can be performed. Further, in the circulation type geothermal utilization apparatus according to the second aspect of the present invention, at least a part of the open bottomed inner pipe rotates the pipe axis of the open bottomed inner pipe around the vertical pipe axis of the bottomed outer pipe. By being constituted by a spirally bent portion extending in the axial direction of the vertical pipe, a swirl component is given to a vertical flow component of the antifreeze liquid (heat medium) flowing through the annular gap, thereby providing a vertical component. Directional flow can be converted to swirling flow.
Thereby, the flow velocity of the actual swirling flow is made higher than the flow velocity of the vertical flow, the heat transfer coefficient on the inner wall surface of the bottomed outer tube is increased, the heat exchange performance is improved, and Alternatively, heat radiation (heat storage) can be performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the invention described in claim 1;

2A is a cross-sectional view taken along the line AA of FIG. 1, and FIG.
BB line sectional view, (c) is a CC line sectional view of FIG.
(D) is a sectional view taken along line DD of FIG. 1.

FIG. 3 is a longitudinal sectional view showing another embodiment of the invention described in claim 1.

FIG. 4 is a longitudinal sectional view showing one embodiment of the invention described in claim 2;

5 (e) is a sectional view taken along line EE of FIG. 4, and FIG. 5 (f) is a sectional view of FIG.
FIG. 4G is a sectional view taken along line FF of FIG.
(H) is a sectional view taken along line HH in FIG. 4.

FIG. 6 is a longitudinal sectional view showing another embodiment of the invention described in claim 2.

FIG. 7 is a longitudinal sectional view of a conventional example.

[Explanation of symbols]

 Reference Signs List 1 soil 2 bottomed outer pipe 3 annular gap 4 open bottomed inner pipe 5 valve box sheet 6 double pipe 8 circulation system 9 heat exchanger 10 bent section 11 spiral bent section C1 vertical pipe axis of bottomed outer pipe C2 Open bottom inner tube tube shaft

Claims (2)

[Claims] 1. A double pipe having a structure in which an open bottom inner pipe is inserted into a bottomed outer pipe buried in soil with an annular gap, and a circulation system for circulating a heat medium through the double pipe. In the circulation type geothermal utilization device configured to perform heat collection from the soil or heat release to the soil by the heat exchanger, at least a part of the open bottomed inner pipe extends in a vertical pipe axis direction of the bottomed outer pipe. A circulation type geothermal utilization device, wherein a meandering bent portion is provided. 2. A double pipe having a structure in which an open bottom inner pipe is inserted into a bottomed outer pipe buried in soil with an annular gap, and a circulation system for circulating a heat medium through the double pipe. In the circulating-type geothermal utilization apparatus configured to perform heat collection from the soil or heat release to the soil by the heat exchanger, at least a part of the open-bottomed inner pipe has a pipe axis of the open-bottomed inner pipe. A circulation type geothermal utilization apparatus characterized in that it is constituted by a spirally bent portion which is turned around a vertical pipe axis of a bottom outer pipe and extended in the vertical pipe axis direction.