KR102355249B1 - Slope excavation method of geothermal hole for securing heat capacity and Construction Method of underground Heat Exchanger - Google Patents

Abstract

{x : 기준선 상 거리, y : 원하는 심도 × sin(각도), z : 원하는 심도 × cos(각도)} 열간섭이 없는 이격거리를 만족하도록 지열공 간의 각도를 산출한다.The present invention relates to an inclined excavation method of a geothermal well for securing heat capacity and a method of constructing a geothermal heat exchange device in a geothermal hole in a narrow site. It aims to operate an underground geothermal heat exchanger without site restrictions.
The inclined excavation method of a geothermal hole for securing heat capacity according to the present invention starts by excavating the inlet of a neighboring geothermal well to maintain a minimum separation distance that does not consider thermal interference at the baseline, and At a certain depth, the excavation is inclined at a certain angle to maintain a separation distance capable of recovering geothermal heat without thermal interference, and through the following equation for calculating the distance between the geothermal spaces,

{x: distance on the baseline, y: desired depth × sin(angle), z: desired depth × cos(angle)} Calculate the angle of the geothermal space to satisfy the separation distance without thermal interference.

Description

Slope excavation method of geothermal hole for securing heat capacity and Construction Method of underground Heat Exchanger

The present invention relates to a method for excavating a geothermal well, and more particularly, to a method of excavating an inclined geothermal hole for securing heat capacity for excavating a geothermal hole so that sufficient geothermal heat capacity can be secured even in a narrow construction site in an urban area, and a method for constructing a geothermal heat exchange device it's about

This section provides background information related to the content of the present application and does not necessarily constitute prior art.

Interest in high-efficiency geothermal energy is growing due to the government's expansion of the use of renewable energy and the Zero Energy Building (ZED) policy.

However, in the case of geothermal energy, a geothermal geothermal heat exchanger is essential, and for this, a process of excavating and constructing geothermal holes from the surface to a depth of 100 to 500 m from the ground surface at appropriate intervals is essential. Up to now, in the case of the vertically sealed type, the attempt was made to excavate the geothermal hole while securing vertical straightness to minimize friction when inserting the heat exchange coil tube. In addition, geothermal wells have been excavated to ensure vertical straightness.

According to the installation environment of such geothermal energy, it is recommended to maintain a minimum interval of 5 m or more in the case of a vertically sealed type and 10 m or more in the case of an open type in order to obtain an appropriate heat capacity and facilitate heat transfer in the ground. In accordance with these considerations, the quantity of geothermal holes required to secure geothermal energy of a certain heat capacity is calculated, and an appropriate area for excavating geothermal holes is calculated based on the calculated quantity of geothermal holes.

In addition, the calculated geothermal hole excavation site often encounters a problem in that it is difficult to secure sufficient geothermal hole excavation site, especially in the city center where new buildings are concentrated. This problem eventually leads to the installation of fuel cells, which do not occupy a large area for installation, while the efficiency remains at 0.8 units, and eventually operation is refused due to the lack of economic feasibility.

Registered Patent No. 10-1511198 Registered Patent No. 10-0885302

The present invention is to solve the above problems, and to provide a method for inclined excavation of a geothermal hole and a method for constructing an underground geothermal heat exchange device for excavating a geothermal hole so that sufficient geothermal heat capacity can be secured even in a narrow construction site in downtown. have.

Excavating a geothermal well at intervals of 10 m while maintaining vertical prominence at the ground surface maintains the same distance from the top of the geothermal hole to the bottom in theory, while changing the vertical straightness of the excavated geothermal well to 1° from the ground If the geothermal hole is excavated at an inclination angle by maintaining the inclination angle inside and out, even if the arc of the outer circumferential surface of the geothermal hole is in contact with the ground surface, the effect is obtained that the geothermal holes are separated underground, and this phenomenon becomes larger as the depth increases. distance can be obtained.

As a result, the present invention has an inclination angle and a deviation of the inclination angle from that of an adjacent geothermal hole. As the depth of the geothermal hole is excavated, the distance between the geothermal space increases and the heat transfer volume of the geothermal hole increases. The solution principle is to further improve the heat exchange efficiency.

The inclined excavation method of a geothermal hole for securing heat capacity according to the present invention starts by excavating the inlet of a neighboring geothermal well to maintain a minimum separation distance that does not consider thermal interference at the baseline, and At a certain depth, it is characterized in that the excavation is inclined at a certain angle to maintain a separation distance capable of recovering geothermal heat without thermal interference.

{x : 기준선 상 거리, y : 원하는 심도 × sin(각도), z : 원하는 심도 × cos(각도)} 열간섭이 없는 이격거리를 만족하도록 지열공 간의 각도를 산출하는 것을 특징으로 한다.The present invention is through the following equation for calculating the distance between the geothermal space,

{x: distance on the baseline, y: desired depth × sin (angle), z: desired depth × cos (angle)} It is characterized in that the angle of the geothermal space is calculated to satisfy the separation distance without thermal interference.

According to the method of digging a geothermal well for securing heat capacity and the construction method of a geothermal heat exchange device according to the present invention, the minimum distance between geothermal holes is maintained without considering thermal interference on the ground surface, but thermal interference does not occur at the depth of recovering geothermal heat. Supply geothermal heat by securing a large number of geothermal holes even in a narrow site by maintaining Therefore, a greater number of geothermal holes can be constructed than when constructing geothermal holes with a separation distance of 10 m from the surface of the earth). has an improving effect.

1 is a schematic diagram of the excavation of geothermal holes by the inclined excavation method of the geothermal hole for securing heat capacity according to the present invention.
2 to 4 are exemplary views of the inclined excavation of the geothermal hole by the inclined excavation method of the geothermal hole for securing the heat capacity according to the present invention, respectively.
5 is a schematic diagram (spatial coordinate system) of a geothermal hole inclined drilling according to the present invention.
Figure 6 is an exemplary construction view of the underground geothermal heat exchange device according to the present invention.

In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification.

The inclined excavation method of the geothermal hole for securing the heat capacity according to the present invention is a method of inversely calculating the angle of the geothermal hole using the equation for calculating the distance between the geothermal holes using the angle of the geothermal hole, and the specific method is as follows.

1. Calculate the distance between geothermal spaces.

As shown in FIG. 1, in the ground surface, perforations are made at intervals of 5 m, for example, at intervals L1 that do not consider thermal interference along the baseline, and the perforations are inclined in a zig zag form in a direction perpendicular to the reference line. perforation is made. For example, with respect to the reference line, the first geothermal hole 1 is obliquely drilled in one direction, and the second geothermal hole 2 is obliquely drilled in the opposite direction to one side.

At this time, the distance from the arbitrary point of the first geothermal hole (1) to the arbitrary point of the second geothermal hole (2) can be calculated using the Pythagorean theorem, and using the three-dimensional coordinate system (x, y, z) Calculate.

x : distance on the baseline (x ₁ : geothermal well 1, x ₂ : geothermal hole 2)

y : desired depth × sin(angle) (y ₁ : geothermal well 1, y ₂ : geothermal hole 2)

z : desired depth × cos (angle) (z ₁ : geothermal well 1, z ₂ : geothermal hole 2)

<Calculation example>

Geothermal hole No. 1 (1) is 0.5 ^o inclined to the left, and geothermal hole 2 (2) is 1.0 ^o inclined drilled to the right. sin 0.5 ^o = 0.008726535, cos 0.5 ^o = 0.9999692, sin 1.0 ^o = 0.017452406, cos 1.0 ^o = 0.9998477.

The distance (L1) from the ground surface of the first geothermal well (1) and the second geothermal well (2) is 5 m.

The distance between geothermal well 1 and 2 at a depth of 50 m is

1) Geothermal hole No. 1 (1) 50m depth coordinates

x ₁ : starting point, so 0

y ₁ : 50m x sin (0.5 ^o ) = 50 x 0.008726535 = 0.436327

z ₁ : 50 m x cos (0.5 ^o ) = 50 x 0.9999692 = 49.9981

Coordinates of _{geothermal hole 1 (x 1} , y 1 , z ₁ ) = (0, 0.436327, 49.9981)

2) Geothermal hole #2 50m depth coordinates

x ₂ : 5 m, so 5

y ₂ : 50m x sin (1 ^o ) = 50 x -0.017452406 = -0.87262 (opposite "-")

z ₁ : 50 m x cos (1 ^o ) = 50 x 0.9998477 = 49.99238

Coordinates of geothermal hole 2 (2) (x ₂ , y ₂ , z ₂ ) = (5, -0.87262, 49.99238)

3) the distance between two points

When the distances for each depth of type 1, type 2, and type 3 are calculated in the same way as above, Table 1 (distance by depth according to the inclined perforation type) is shown below. Type 1, type 2, and type 3 are defined in FIGS. 2 to 4 and as follows. 2 to 4 show only an example, and the present invention enables inclined excavation in various directions through the above-described formula.

type 1 : Geothermal hole 1 (1) and geothermal hole 2 (2) both have ^{an angle of 0.5 o} and the direction is opposite (opposite to the reference line)

type 2 : The angle of the first geothermal hole (1) is 0.5 ^o , the angle of the second geothermal hole (2) is 1.0 ^o and the direction is opposite (opposite to the reference line)

type 3 : Geothermal hole 1 (1) and hole 2 (2) are both at ^{an angle of 1.0 o} and opposite in direction (opposite to the reference line)

depth
(m) Distance between two points (m) type1 type2 type3 ①~①' ①~②' ②~②' 50 5.07558 5.16850 5.295835 100 5.29586 5.64389 6.097824 150 5.64391 6.35770 7.239667 200 6.09790 7.23975 8.586841 250 6.63612 8.23616 10.057168 300 7.23981 9.31029 11.603928 350 7.89397 10.43817 13.200280 400 8.58706 11.60414 14.830218 450 9.31040 12.79779 16.483782 500 10.05746 14.01205 18.154517

2. Calculation of the angle of the geothermal well.

The geothermal space distance (L2) for efficient heat acquisition during on-site construction requires, for example, maintaining an interval of 10 m or more. was calculated, and the result is shown in Table 2 below (angle at which the distance between the two points at the desired depth of the first geothermal well and the second geothermal well is 10 m or more).

depth An angle where the distance between two points is more than 10 m 50 m 5.0 ^o 100 m 2.5 ^o

go. Estimation of the minimum inclination angle with two clearances greater than 10 m at a depth of 50 m

And can be calculated by applying the above equation, that is, calculate the coordinate by using the trigonometric functions, and the clearances is possible to calculate the angle by changing the angle is at least 10m, and as a result, the tilt angle 5.0 ^o one time 50m It was confirmed to reach a distance of more than 10 m from the depth of field. Table 3 shows the distance by depth when the ^{inclination angle is 5 o.}

Depth (m) Distance between two points (m) 50 10.047947 100 18.134082 150 26.620502 200 35.219026 250 43.863776 300 52.531938 350 61.213565 400 69.903641 450 78.599364 500 87.299046

me. Estimation of minimum inclination angle with two clearances greater than 10 m at a depth of 100 m

The calculation was carried out in the same way as above, and as a result, it was confirmed that a distance of 10m or more was reached at a depth of 100m when the ^{inclination angle was 2.5 o.} Table 4 shows the distance by depth when the ^{inclination angle is 2.5 o.}

Depth (m) Distance between two points (m) 50 6.63525 100 10.05515 150 14.00852 200 18.15005 250 22.37549 300 26.64497 350 30.94025 400 35.25190 450 39.57458 500 43.90502

In the present invention, a method of checking the excavation angle of a geothermal hole using big data is also possible, and a database is constructed by calculating various excavation angles according to the separation distance for securing depth and heat capacity.

The database specifies the excavation angle as a single numerical value, and sets the separation distance for securing heat capacity by depth as a variable (see Table 4), and specifies the separation distance (for example, 10 m) for securing heat capacity as a single numerical value, Various types, such as a form of building the excavation angle by depth as data (refer to Table 5), and a form using two separation distances to secure depth and heat capacity as variables (refer to Table 6), that is, all types of excavation angles form is possible. In addition, the database is constructed in various ways by using the inter-surface distance of the geothermal wells as a variable. Of course, according to the size of the available area on the earth's surface, the spacing of the geothermal holes can be changed flexibly, and the excavation angle can be arbitrarily adjusted by the database to form the geothermal holes.

depth of field digging angle 50m 1° 100m 3° 150m 7°

division 10m 15m 20m 50m 1° 1.5° 2° 100m 3° 5° 7° 150m 7° 9° 11°

The manager inputs a variable (depth in FIG. 2, depth and separation distance in FIG. 3) through the program, and the program compares the input value with the variable value in the database to extract and display the excavation angle.

In addition, the above equation may be modified and utilized as the following equation for calculating the value of the angle.

go. Calculation method: using the Pythagorean theorem using coordinates in space

In the ground surface, drilling is made at intervals of a m along the baseline, and the drilling is made obliquely in the form of zig zag in a direction perpendicular to the baseline. For example, with respect to the baseline, geothermal hole No. 1 is inclined in the left direction, and geothermal hole No. 2 is inclined drilling in the right direction.

At this time, the distance from an arbitrary point on the 1st ball to an arbitrary point on the 2nd ball can be calculated using the Pythagorean theorem, and for easy calculation, it is calculated using a three-dimensional coordinate system (x, y, z) (Fig. 5) Reference).

When the desired distance tm in each geothermal space at a certain depth, the minimum inclination angle can be calculated using the formula in Equation 2 below (however, θ ₁ ° = θ ₂ °, b = c, assuming that the slope drilling depth is the same)

or

: 이웃하는 지열공들의 열용량 확보를 위한 심도에서의 이격거리, a : 이웃하는 지열공들의 지표면에서의 이격거리, b : 기준이 되는 1번 지열공의 지표면에서 열용량 확보를 위한 지점까지의 심도, c : 2번 지열공의 지표면에서 열용량 확보를 위한 지점까지의 심도

: Separation distance at the depth for securing heat capacity of neighboring geothermal wells, a : Separation distance from the ground surface of neighboring geothermal wells, b : Depth from the ground surface of the reference geothermal well No. 1 to the point for securing heat capacity, c : Depth from the surface of the geothermal well No. 2 to the point for securing heat capacity

※ Reason to assume inclined drilling b = c: Even if a geothermal hole is drilled at an arbitrary inclination angle from the surface in the field, the two values are theoretically different because the drilling depth (depth) is expressed by the drilling rod, etc., but in the field The difference is within a range that is negligible.

me. Calculation example

Calculation of the minimum angle at which the interval between ①’ and ②’ is 10 m at the desired depth of drilling (b, c = 100 m) when the distance between the first hole and the second hole is 5 m. arbitrarily determined value).

a = 5 m

b = c = 100 m

= 10 m 이때 원하는 임의의 최소 경사

을 계산하면t =

= 10 m then any desired minimum slope

If you calculate

As a result, the angle (θ ₁ +θ ₂ ) between the two geothermal spaces becomes 5°.

In the same way as above, if the angle for each depth of inclined drilling according to the desired separation distance (t = 10m) is calculated, it is shown in Table 7 (Distance by depth according to the inclined drilling type (the desired separation distance from the inclined depth of 10m)).

Depth of slope
(m) Inclined drilling (angle, °) 50 surface 100 5.0 150 2.5 200 1.7 250 1.2 300 1.0 350 0.8 400 0.7 450 0.6 500 0.6

The underground geothermal heat exchanger construction method according to the present invention includes excavating and drilling geothermal holes through the above-described method, installing a geothermal recovery means in the excavated and drilled geothermal holes, and installing the geothermal recovery means and heat exchange means do.

The geothermal recovery means is, for example, as shown in FIG. 6, the submersible pump (3) for pumping the ground water inside the geothermal hole (1) and the ground water pumped by the submersible pump (3) heat exchange means (6) Pumping up groundwater, including a supply pipe (4) for supplying to the heat exchanger and a return pipe (including a perforated part) (5) that returns the groundwater that has passed through the heat exchange means to the geothermal hole (1), U-shaped to circulate the geothermal hole A circulation pipe that recovers geothermal heat through circulation of a heating medium is possible.

In addition, after collecting the groundwater of the geothermal hole using the water collection tank 7 , it is supplied to the heat exchange means 6 (heat pump) through the supply pipe 4 and returned to the geothermal hole that has passed through the return pipe 5 . It is also possible, at this time, the circulation pump can be configured inside or outside the water collection tank (7).

Since the geothermal hole is inclined, the geothermal recovery means inserted in the geothermal hole may collide or stick to the hole wall of the geothermal hole. A central alignment member may be used to maintain the center. The central alignment member is coupled to the periphery of the geothermal recovery means and has a ring shape and the edge thereof is supported on the hole wall of the geothermal hole.

The heat exchange means may be a heat exchanger, a heat pump, etc. that use the geothermal heat recovered through the geothermal heat recovery means as a heat source to produce heating and cooling heat.

1: No. 1 geothermal well, 2: No. 2 geothermal well
3: submersible pump, 4: supply pipe
5: return pipe, 6: heat exchange means

Claims (5)

In the baseline, it begins by excavating the inlet of the neighboring geothermal well to maintain the minimum separation distance that does not consider thermal interference. Determine the angle to excavate the geothermal hole,
Calculating the angle of the geothermal hole through Equation 1 below for calculating the distance between the geothermal holes,

x: distance on baseline
y : desired depth × sin (angle)
z : desired depth × cos (angle)
Or, through Equation 2 below

: Separation distance from the depth for securing heat capacity of neighboring geothermal wells, a : Separation distance from the ground surface of neighboring geothermal wells, b : Depth from the ground surface of the reference geothermal well to the point for securing heat capacity, c : Depth from the ground surface of the reference geothermal well and the neighboring geothermal well to the point to secure heat capacity
An inclined excavation method of a geothermal hole for securing heat capacity, characterized in that calculating the angle of the geothermal hole. delete The method according to claim 1, By applying Equation 1 or Equation 2, a database including a distance on a baseline and an excavation angle according to a separation distance to secure a depth and heat capacity is constructed, and the input value and the database are compared through a program An inclined excavation method of a geothermal hole for securing heat capacity, characterized in that extracting and displaying the excavation angle through A first step of inclined excavating a geothermal hole through the method of claim 1 or 3;
a second step of installing a geothermal recovery means for recovering geothermal heat in the geothermal hole excavated through the first step;
and a third step of installing a heat exchange means by connecting to the geothermal heat recovery means installed in the second step. The method according to claim 4, wherein in the second step, a supply pipe and a perforated return pipe are installed in the geothermal hole as the geothermal recovery means, and in the third step, a heat pump connected to the supply pipe is installed as the heat exchange means, and the A method of constructing an underground geothermal heat exchange device, comprising installing a water collecting tank to be connected to a heat pump and connecting it to the return pipe to return groundwater to the geothermal hole through the water collecting tank.

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