KR20120134659A

KR20120134659A - Combined type geothermal system and construction method using large aperture punchung

Info

Publication number: KR20120134659A
Application number: KR1020110053731A
Authority: KR
Inventors: 하은룡
Original assignee: 주식회사 산하이앤씨
Priority date: 2011-06-03
Filing date: 2011-06-03
Publication date: 2012-12-12
Also published as: KR101303575B1

Abstract

PURPOSE: A hybrid geothermal system using large boreholes and construction method thereof are provided such that ground water freely flows as horizontal boreholes are formed in a direction of an aquifer or radial direction. CONSTITUTION: A hybrid geothermal system using large boreholes comprises a water reservoir(2), large boreholes, a plurality of perforated pipes(11), a composite heat exchange pipe(4), an upper valve(5), a lower valve(6), and a filing material(7). The inside of an underground space is finished by reinforced concrete, and the water reservoir is formed after the ground(1) is excavated to the planned depth. The large boreholes are formed at the side wall of the water reservoir along a peripheral direction at constant intervals. The perforated pipes are inserted into the large boreholes, and ground water smoothly flows in the water reservoir. The vertical and horizontal heat exchanging pipes of the composite heat exchange pipe are installed in the water reservoir. The upper and lower valves are installed in the composite heat exchange pipe, and open-type and close-type systems are selectively applied. The filling material is charged in the upper part of the water reservoir to protect geothermal heat.

Description

Mixed type geothermal system utilizing large diameter drilling and construction method {COMBINED TYPE GEOTHERMAL SYSTEM AND CONSTRUCTION METHOD USING LARGE APERTURE PUNCHUNG}

The present invention relates to a hybrid geothermal system using a large diameter perforation and a construction method thereof, and more particularly, an open type and a closed type horizontal type and a vertical type which allow the use of heat of underground medium and groundwater in a geothermal system. The present invention relates to a hybrid geothermal system using a large diameter drilling having a composite heat exchange pipe having a composite structure, and a construction method thereof.

In general, as an energy source used for cooling and heating, fossil fuels such as coal, petroleum, and natural gas are used, or power energy produced using these fossil fuels or nuclear power is mainly used. However, since fossil fuels have a disadvantage of polluting water quality and the environment due to various pollutants generated during the combustion process, in recent years, development of alternative energy to replace them has been actively conducted. Among these alternative energies, research on wind power, solar heat, geothermal energy, etc., which have infinite energy sources, and air-conditioning devices using them are used. These energy sources have the advantage of obtaining energy with little effect on air pollution and climate change. On the other hand, the energy density is very low.

In particular, in order to obtain energy by using wind and solar heat, a large area must be secured along with the limit of the installation site. These devices have low energy production capacity per unit and are expensive to install and maintain. Therefore, many air-conditioning and heating devices using geothermal energy, which require relatively low cost for installation and maintenance, are used. This is a technology using underground thermal energy having a temperature of 10 to 20 ° C.

The type of geothermal system is typically classified into a closed type or an open type according to the circuit configuration of the pipe (heat exchanger) that recovers the geothermal heat.

An open type is an open pipe that carries water from a source, lake, river, or well, and can be applied where there is an abundant source. The general application of the open geothermal system has the same structure and facilities as the groundwater core wells, and the groundwater is pumped out of the groundwater instead of using the groundwater. . Compared to the heat-exchanging type of heat-exchanging heat (water or antifreeze) and geothermal heat in the pipe, the open type has the advantage of high heat transfer effect and low installation cost because geothermal heat is recovered directly into the pipe. The disadvantage of the open type is that maintenance is required compared to the closed circuit, and groundwater is exposed from the ground, which may cause groundwater contamination.

Enclosed type refers to an air-conditioning system that recovers geothermal heat or releases heat through underground heat exchangers installed in the ground.The solvent for heat exchange is circulated by the circulation pump in the closed circulation pipe, but is not in direct contact with the groundwater. As a result, groundwater contamination may not be greatly concerned, which is advantageous in terms of groundwater environmental conservation. Closed type is divided into vertical type and horizontal type according to the buried environment.

Horizontal systems can be considered if there are enough sites to bury underground heat exchangers around the target building. It is usually buried in a trench 1.5-3.0m deep and can be arranged in a straight or sleek form. The construction cost is relatively cheaper than the vertical type because there is no borehole drilling process, but the efficiency is inferior because the heat exchange pipe is buried at a relatively low depth of 1.5m ~ 3.0m from the ground. It is common.

Therefore, most of them are applied vertically. In the case of vertical type, after securing the land, excavate vertical bore-holes in depth of 60 ~ 180m and wind them once or twice in each borehole to U-shaped pipe. The installed heat exchanger is installed. After installation, each borehole is filled with bentonite or cement, which is impermeable, and then grouted. During the grouting process, the boreholes are filled with special materials to prevent the infiltration of surface water into the aquifer or the penetration of water due to the failure of adjacent aquifers.

In general, grouting materials have lower heat transfer properties and are more expensive than ordinary backfills. Recently, when manufacturing a field-pouring pile, a method of manufacturing a pile by embedding a heat exchange pipe therein is used. Accordingly, the heat exchange pipe constituting the geothermal heat exchanger is integrally installed inside the pile, thereby facilitating the installation of the ground heat exchanger. It is easy to do.

A heat transfer fluid is injected into the heat exchange pipe of the geothermal air conditioning system installed as described above in order to exchange heat with the ground heat. The geothermal air conditioning system takes the heat transfer fluid contained therein through the heat exchange pipe and stores the heat transfer fluid in this state. Forced circulation by the operation of the to move to the required place to perform cooling or heating.

This heating and cooling is possible because geothermal heat is lower than the air temperature in summer and higher than the air temperature in winter. In the case of cooling, geothermal heat is extracted from the room and transferred to the ground. You can heat up. Cooling and heating can be easily switched between cooling and heating mode by changing the flow direction of the heat transfer fluid through a switch operation installed in the heat pump.

The vertical type has a higher cost for drilling than the horizontal type, which is a burden on the economics.

On the other hand, many geothermal systems and construction methods for utilizing the heat of the underground medium and groundwater have been proposed in the related art.

By the way, the conventional geothermal system as described above, in the geothermal system, is composed of a closed type or an open type, respectively, and does not apply a mixed type and an open type, and in particular, an open type geothermal system utilizing a conventional underground medium is small. Since the groundwater is used by drilling the hole, there is a disadvantage in that the operation is restricted by the change of the groundwater. In particular, in the conventional geothermal system, the closed type has a disadvantage of occupying a large area of the installation site because it forms a plurality of boring holes, and there is a problem of limiting the inflow of groundwater because only the boring holes are formed.

Therefore, the present invention is to solve the above-mentioned problems, water storage tank of the dual structure to form a certain size of underground space to increase the geothermal efficiency to use geothermal heat and to increase the heat transfer efficiency of the formed underground space The upper structure without groundwater is installed in the underground heat exchanger and water storage tank, which is composed of underground space, which is designed to increase energy efficiency by filling with water, and a large number of radial holes are formed in the water storage tank to free the inflow of groundwater. The purpose is to provide a hybrid geothermal system using large diameter drilling and its construction method which can improve the convenience of maintenance, minimize the installation site, and improve the economics and efficiency.

According to the present invention, in a mixed geothermal system utilizing a large diameter perforation, excaving from the ground surface to a predetermined depth to form a predetermined underground space, and then the water storage tank formed of reinforced concrete of a certain thickness inside the underground space Wow; A plurality of perforation holes installed at a predetermined interval up and down along the circumferential direction of the sidewalls from the sidewalls of the water storage tank, a plurality of perforated pipes inserted into the perforation holes to facilitate groundwater flow into the water storage tank; The upper and lower valves installed in the composite heat exchange pipe to selectively apply the open and closed system and the composite heat exchange pipe installed by mixing the vertical heat exchange pipe and the horizontal heat exchange pipe among the closed heat exchange pipes in the water storage tank. Wow; It is achieved by a mixed geothermal system utilizing a large diameter perforation, characterized in that it comprises a filler filling the upper portion of the water reservoir for geothermal protection.

Here, it is preferable that the water storage tank is partitioned into an upper storage tank and a lower storage tank by partition walls.

And it is effective to further include a heat exchange pipe installed in the complex heat exchange pipe is installed to send the water used for cooling and heating back to the lower reservoir when applying the open system.

According to the present invention is installed on one side of the water storage tank and drilled in the vertical direction for the groundwater level check and groundwater pumping in the area adjacent to the reservoir tank, and from the outside to check the change of the groundwater level inside the drilling hole Or it is preferable to further include an underground water level meter provided in the reservoir so that it can be automatically monitored, a perforated pipe for collecting the groundwater in the drilling hole and a transport pipe installed to send the groundwater in the drilling hole to the reservoir. .

On the other hand, the present invention, in the mixed geothermal system construction method using a large diameter drilling, reinforcement of a certain thickness so as to excavate from the ground surface to the planned depth to form a predetermined underground space and to use the underground space according to the ground water level distribution Installing a water storage tank of at least one sealed structure in concrete; Installing a plurality of perforated pipes at a sidewall of the water storage tank in a circumferential direction of the sidewalls and installing a plurality of perforated pipes so as to be inserted into the perforated holes to facilitate groundwater flow; A process of installing a composite heat exchange pipe in which both a vertical heat exchange pipe and a horizontal heat exchange pipe are applied among the sealed heat exchange pipes in the water storage tank, and an upper valve and It is also achieved by a method of installing a mixed geothermal system utilizing a large diameter perforation, comprising the step of installing a lower valve, and the step of installing a filler on the water reservoir for geothermal protection.

In this case, it is preferable to include a step of installing the heat exchange pipe is installed in the complex heat exchange pipe to send the water used for cooling and heating when the open system is applied back to the water storage tank.

And installing a perforated hole vertically perforated to check the groundwater level and pump the groundwater in an area adjacent to the reservoir in one side of the water storage tank, and to check the change of the groundwater level inside the perforated hole manually or externally. And installing a groundwater level meter inside the reservoir to automatically monitor, and installing a feed pipe to send groundwater in the perforated hole and groundwater in the perforated hole to the reservoir. It is effective.

The present invention as described above, by utilizing the groundwater or the water filled in the underground space and the underground space of the large jeongho structure of the present invention, there is an advantage of reducing the installation site area is not required as a plurality of drilling holes as in the case of the conventional sealed type In addition, the heat of the ground improves the contact area with the internal underground medium and effectively conducts heat transfer, thereby increasing the heat exchange efficiency of the underground heat exchanger.

The present invention, by applying an open type and a sealed type at the same time to eliminate the risk of groundwater level changes and efficient use of geothermal system, it is possible to change the open type and sealed type according to the installation of the switchgear, it is possible to use the efficient geothermal. In addition, there is an advantage in that the groundwater inflow can be freed by forming a horizontal aquifer or radial horizontal drilling hole in the water storage tank.

In addition, by utilizing a large jeongho structure has the effect of reducing the construction area, which was a problem in the existing closed type, there is an effect of easy maintenance of the geothermal system and peripheral devices because the internal charging is not performed.

As a result, by applying the present invention can not only take advantage of the advantages of the closed type and open type, but also can use the advantages of the horizontal type and vertical type among the closed type can reduce the construction cost and construction period, easy maintenance and overall geothermal There is an effect of improving the cooling and heating efficiency of the system.

Figure 1a is a cross-sectional view showing the configuration of a hybrid geothermal system using a large diameter drilling according to the present invention,
1b to 1c is a cross-sectional view showing another example of the water storage tank according to the present invention,
2 is a partially enlarged view showing a detailed structure of the perforation hole, the perforated tube installed in the circumferential direction of the lower reservoir,
3 is an exemplary view showing a modification of the composite heat exchange pipe according to the present invention,
Figure 4 is a process diagram according to the construction of the hybrid geothermal system using a large diameter drilling according to the present invention,
5 is an exemplary view showing a construction method of a mixed geothermal system using a large diameter drilling according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In the above description of the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

Figure 1a is a cross-sectional view showing the configuration of a mixed geothermal system utilizing a large diameter drilling according to the present invention, Figure 1b is a cross-sectional view showing another example of the water storage tank according to the present invention, Figure 2 is installed in the circumferential direction of the lower reservoir This is an enlarged view showing the detailed structure of perforated hole and perforated pipe.

As can be seen in these figures, the mixed geothermal system utilizing the large-diameter perforation according to the present invention has a predetermined underground space (H) formed by excavating from the surface of the ground (1) to a planned depth, and the underground space (H). A water storage tank 2 formed of reinforced concrete of a predetermined thickness is provided inside. Here, the drilling of the underground space H to a large diameter is performed by minimizing the depth of drilling and by applying the composite heat exchange pipe 4 in which the horizontal heat exchange pipe 4a and the vertical heat exchange pipe 4b are mixed in the hermetic type described below. This is because it is possible to secure an economical and efficient temperature maintenance function with the advantages of horizontal type and vertical type. Therefore, in the present invention, the underground space (H) is perforated in the ground from a small diameter of about 150mm to a large diameter of about 3m.

The water reservoir 2 according to the present invention may be partitioned into an upper reservoir 3 ′ and a lower reservoir 3 ″ by the partition wall 3 a. The upper reservoir 3 ′ is an underground water level at the surface. The distribution depth is to be positioned to a certain depth lower, and the lower reservoir (3 ") is to be located below the upper reservoir (3 '). In addition, the upper reservoir 3 'is a hermetically sealed reservoir, and the internal water cannot be naturally discharged to the outside and the surface water cannot be introduced from the outside.

In the circumferential direction of the side wall of the lower storage tank 3 "according to the present invention, a plurality of drilling holes 10 are radially installed at regular intervals up and down, and inside the lower storage tank 3" inside the drilling hole 10. A plurality of perforated pipes 11 are installed to freely flow the groundwater, and a plurality of holes 11a are formed on the outer surface of the perforated pipes.

The oil pipe 11 according to the present invention has a function of maintaining a constant flow rate of the ground water introduced into the water storage tank 2 and a filter role to prevent the sand, etc. flowing out through the water vein into the water storage tank (2). And, the size and installation length of the opening of the perforated pipe 11 is installed to adjust to suit the site conditions.

In the water storage tank 2 according to the present invention, the composite heat exchange pipe 4 is installed by mixing and applying the vertical heat exchange pipe 4a and the horizontal heat exchange pipe 4b among the sealed heat exchange pipes.

FIG. 3 shows the shape of the composite heat exchange pipe 4 to which both the vertical heat exchange pipe 4a and the horizontal heat exchange pipe 4b are applied. The composite heat exchange pipe (4) can be divided into circular, square, rectangular, etc. according to the shape of the water storage tank (2), in order to increase the efficiency of the heat exchanger horizontal heat exchange pipe consisting of a spiral and the straight line of the c, d shape, etc. (4a) and the vertical heat exchanger pipe (4b) connecting the horizontal heat exchanger pipes to a lower portion at a predetermined interval to increase the contact area of the composite heat exchanger pipe (4) and increase the contact area of the filling material in the water reservoir (2). By not injecting or grouting, the water in the water storage tank 2 is configured to efficiently transfer geothermal heat.

The upper valve 5 and the lower valve 6 are installed in the composite heat exchange pipe 4 according to the present invention so that open and closed systems can be selectively applied, and the upper portion of the water storage tank 2 for geothermal protection. Is filled with a filler (7).

Meanwhile, the heat exchange pipe 12 is installed in the composite heat exchange pipe 4 according to the present invention to send the water used for cooling and heating to the lower storage tank 3 ″ again when the open system is applied, and the water storage tank 2 is partitioned. When partitioned into the upper reservoir 3 'and the lower reservoir 3 "by the wall 3a, the lower end of the heat exchange pipe 12 is installed in the lower reservoir 3".

According to the present invention, by installing a punched hole 20 in the vertical direction on one side of the water storage tank (2) to check the groundwater level 100 and the groundwater pumping in the area adjacent to the water reservoir (2) In addition, by installing the groundwater level measuring instrument 21 inside the drilling hole 20 to check the change of the groundwater level from the outside to monitor manually or automatically. And the drilling hole 20 is installed to take the ground water in the drilling hole 20 and the perforated pipe 22 is installed therein, and the ground water in the drilling hole 20 to send to the water storage tank (2) The feed pipe 23 is provided.

On the other hand, Figure 4 is a process diagram according to the construction of a mixed geothermal system using a large diameter drilling according to the present invention, Figure 5 is an exemplary view showing a construction method of a mixed geothermal system using a large diameter drilling according to the present invention.

As can be seen in the drawings, according to the present invention, first, to excavate from the ground surface to the planned depth to form a certain size underground space (H) and to use the underground space (H) according to the groundwater level distribution The step (S1) of installing the water storage tank (2) of at least one sealed structure with reinforced concrete of thickness. Here, the water storage tank 2 may be partitioned into the upper storage tank 3 'and the lower storage tank 3 "by the partition wall 3a.

Subsequently, a plurality of perforated pipes 11 are installed in the periphery direction of the side wall of the water storage tank 2 to install the perforation holes 10 at regular intervals and to be inserted into the perforation holes 10 to facilitate the flow of groundwater. The process (S2) to proceed.

Thereafter, in the water storage tank 2, the process of installing the composite heat exchange pipe 4 in which both the vertical heat exchange pipe 4a and the horizontal heat exchange pipe 4b are applied (S3) is performed. After the process (S4) of installing the upper valve (5) and the lower valve (6) in the composite heat exchange pipe (4) to selectively apply a closed system, the water reservoir (2) for geothermal protection It is constructed in the step (S5) of installing the filler (7) on the top.

And according to the present invention, further comprising the step (S6) of installing the heat exchange pipe 12 to be installed in the complex heat exchange pipe (4) to send the water used for cooling and heating in the open system application back to the water storage tank (2) In addition, on one side of the water storage tank (2) installed in the area adjacent to the water storage tank (2) for the ground water level check and groundwater pumping in the vertical direction perforated hole (20) and the ground water inside the drill hole (20) In order to check the above change, the groundwater level measuring instrument 21 is installed inside the reservoir to monitor manually or automatically from the outside, and the perforated pipe 22 and the perforated hole for collecting groundwater inside the perforated hole 20 20) may further include the step (S7) of installing the conveying pipe 23 to send the groundwater inside the water storage tank (2).

As described above, the present invention utilizes groundwater or water filled in the underground space and the underground space of a large Jeongho structure, and thus does not require a plurality of perforation holes as in the case of the conventional sealed type, and reduces the installation site area, and the underground heat is internally. It improves the heat exchange efficiency of geothermal system because it can improve the contact area with underground medium and perform heat transfer effectively.

In addition, the present invention, by applying an open type and a sealed type at the same time to eliminate the risk of the groundwater level change and efficient use of geothermal system, and can change the open type and sealed type according to the installation of the switchgear, efficient use of geothermal heat, water storage tank It is possible to free the inflow of groundwater by installing horizontal perforated holes in the aquifer direction or radial holes in the aquifer. In addition, the construction area, which has been a problem in the existing closed type, is reduced by utilizing a large structure, and the maintenance of the heat exchanger and the peripheral device is easy because the internal filling is not performed.

As a result, by applying the present invention can not only take advantage of the advantages of the closed type and open type, but also can use the advantages of the horizontal type and vertical type among the closed type can reduce the construction cost and construction period, easy maintenance and overall geothermal The heating and cooling efficiency of the system is improved.

1: Ground
2: water storage tank
3 ': upper reservoir
3 ": Lower reservoir
4a: vertical heat exchanger pipe
4b: horizontal heat exchanger pipe
5: upper valve
6: lower valve
7: filling material
10: drilling hole
11: Merit Hall
12: heat exchange pipe
20: Perforation hole
21: groundwater level meter
22: merit pipe
23: transfer pipe

Claims

In a mixed geothermal system utilizing large diameter drilling,
A water storage tank 2 formed of reinforced concrete having a predetermined thickness inside the underground space H after excavating to a predetermined depth from the ground surface 1 to form a predetermined underground space H;
A plurality of drilling holes 10 installed at regular intervals in the vertical direction along the circumferential direction of the side wall from the side wall of the water storage tank 2 and inserted into the drilling hole 10 to allow the groundwater flow into the water storage tank 2. A plurality of perforated pipes 11 installed to smoothly;
In the water storage tank 2, a composite heat exchange pipe 4 and an open type and a closed system can be selectively applied by mixing and applying a vertical heat exchange pipe 4a and a horizontal heat exchange pipe 4b among the sealed heat exchange pipes. An upper valve 5 and a lower valve 6 installed on the composite heat exchange pipe 4 so as to be provided;
Mixed geothermal system utilizing a large diameter perforation, characterized in that it comprises a filler (7) filled in the upper portion of the water storage tank (2) for geothermal protection.

The method of claim 1,
The water storage tank (2) is a mixed geothermal system utilizing a large diameter perforation, characterized in that partitioned by the partition wall (3a) formed into an upper reservoir (3 ') and a lower reservoir (3 ").

The method of claim 1,
Mixed type utilizing a large diameter perforation, characterized in that it further comprises a heat exchange pipe (12) installed in the composite heat exchange pipe (4) installed to send the water used for cooling and heating back to the lower reservoir (3 ") when the open system is applied. Geothermal system.

The method of claim 1,
A perforated hole 20 installed at one side of the water storage tank 2 and perforated in a vertical direction for checking the groundwater level 100 and pumping the groundwater in an area adjacent to the water storage tank 2;
In order to check the change in the ground water level inside the drilling hole (20) and the ground water level measuring instrument (21) provided in the reservoir to allow manual or automatic monitoring from the outside,
It further comprises a feed pipe (23) installed to send the ground water in the perforated hole 22 and the ground water in the perforated hole (20) to the water storage tank (2). Hybrid geothermal system utilizing large diameter drilling.

In the construction method of mixed geothermal system using large diameter drilling,
Installing a water storage tank of at least one sealed structure with reinforced concrete of a predetermined thickness so as to form a predetermined underground space by excavating from the ground surface to a predetermined depth and using the underground space according to the distribution of the ground water level;
Installing a plurality of perforated pipes at a sidewall of the water storage tank in a circumferential direction of the sidewalls and installing a plurality of perforated pipes so as to be inserted into the perforated holes to facilitate groundwater flow;
Installing a complex heat exchange pipe to which both a vertical heat exchange pipe and a horizontal heat exchange pipe are applied among the sealed heat exchange pipes in the water storage tank;
Installing an upper valve and a lower valve in the composite heat exchange pipe to selectively apply an open type and a closed type system;
Construction method of a mixed geothermal system using a large diameter perforation comprising the step of installing a filler on the water reservoir for geothermal protection.

6. The method of claim 5,
And a step of installing the heat exchange pipe so as to be installed in the complex heat exchange pipe to send the water used for cooling and heating again to the water storage tank when the open system is applied to the composite heat exchange pipe.

6. The method of claim 5,
Installing a perforated hole in the vertical direction for the groundwater level check and groundwater pumping in the area adjacent to the water storage tank on one side of the water storage tank, and from the outside to check the change of the groundwater level inside the drilling hole Or installing a groundwater level meter inside the reservoir for automatic monitoring;
Construction method of the mixed geothermal system using a large diameter drilling, characterized in that it further comprises the step of installing a conveying pipe to send the ground water and the ground water inside the drilling hole to the water storage tank in the drilling hole inside .