NL2028183B1 - A heat exchange pipe in a geothermal well - Google Patents

Abstract

The invention discloses a heat exchange pipe in a geothermal well, which comprises a first drilling hole, a pump chamber pipe penetrates through the first drilling hole, the bottom of the first drilling hole is provided with a second drilling hole which is located in the pump chamber pipe, the second drilling hole is internally provided with a shaft lining pipe which is internally provided with a pumping pipe, a first filling layer is filled between the first drilling hole and the pump chamber pipe, and a first water stop ring is fixed between the second drilling hole and the shaft lining pipe, a tray is fixed on the top of the first water stop ring, and a second filling layer is filled between the second drilling hole and the shaft lining pipe, the second filling layer is located at the top of the tray, a second water stop ring is fixed between the shaft lining pipe and the pumping pipe, and a water inlet pipe penetrates through the second water stop ring. When the pumping pipe pumps water, the water stored between the shaft lining pipe and the pumping pipe circulates downwards and is heated at the bottom of the shaft lining pipe so as to increase the temperature of underground water, and then hot water is discharged from the pumping pipe so as to lead out the heat energy in the earth crust, thus solving the problem that geothermal energy is difficult to use at present and having good popularization value.

Description

A HEAT EXCHANGE PIPE IN A GEOTHERMAL WELL

TECHNICAL FIELD The invention relates to the technical field of geothermal energy utilization, in particular to a heat exchange pipe in a geothermal well.

BACKGROUND Geothermal energy is the heat energy from the interior of the earth, which is produced by the decay of radioactive materials in the interior of the earth. Geothermal energy contains a huge amount, but its utilization rate is limited due to the limitation of usage. At present, only a few areas use geothermal energy to IO generate electricity. Promoting the utilization of geothermal energy is an effective measure for resource conservation and environmental protection, and it is a way to realize the sustainable development of human society. Geothermal energy, as a renewable energy, has the advantages of wide distribution, low cost, easy to exploitation, cleanness and direct utilization. The trend of geothermal energy is that the closer it’s surface, the lower its geothermal temperature, and the closer its core, the higher the temperature is. Therefore, people choose to drill in a suitable area, then run down the pipeline and inject it into the water body, replacing and carrying out the high temperature in the crust with the water body. The thermal reservoirs of medium-deep geothermal wells are generally sandstone and limestone, and the thermal conductivity is generally 1-3 W/m * K. The traditional construction technology of heat transfer efficiency without water for medium-deep buried pipes has low utilization efficiency of geothermal energy and is difficult to use geothermal energy.

SUMMARY The purpose of the present invention is to provide a heat exchange pipe in a geothermal well, so as to solve the problems existing in the prior art, so that the water stored between the shaft lining pipe and the water pumping pipe circulates downwards and is heated at the bottom of the shaft lining pipe, thereby increasing the temperature of underground water, and then discharging hot water from the water pumping pipe, thereby realizing the heat energy in the earth crust to be led out. In order to achieve the above purpose, the present invention provides the following scheme: the heat exchange pipe in geothermal well comprises a first drilling hole, a pump chamber pipe penetrates through the first drilling hole, the bottom of the first drilling hole is provided with a second drilling hole which is located in the pump chamber pipe, the second drilling hole is internally provided with a shaft lining pipe which is internally provided with a pumping pipe; a first filling layer is filled between the first drilling hole and the pump chamber pipe, and a first water stop ring is fixed between the second drilling hole and the shaft lining pipe, a tray is fixed on the top of the first water stop ring, and a second filling layer is filled between the second drilling hole and the shaft lining pipe, the second filling layer is located at the top of the tray, a second water stop ring is fixed between the shaft lining pipe and the pumping pipe, and a water inlet pipe penetrates through the second water stop ring.

Preferably, the pumping pipe is a thermal insulation pipe, which comprises an inner pipe, and an outer pipe is sleeved outside the inner pipe. The cavity between the inner pipe and the outer pipe is filled with a thermal insulation layer,

which comprises a insulating layer and a thermal insulation layer, and the insulating layer is located inside the thermal insulation layer.

Preferably, a plurality of centering rings are pierced on the pumping pipe, the inner walls of the centering rings are fixedly connected with the water pumping pipe, and the outer walls of the centering rings are connected with the shaft lining pipe.

The out wall of that centering rings is provided with a plurality of water guide grooves.

Preferably, grooves are arranged between the water guide grooves, rollers are axially connected in the grooves, and an elastic layer is laid on the outer sides IO of the rollers.

Preferably, the bottom end of the water inlet pipe is fixed with a filter tube.

Preferably, the wall of the filter tube tube is provided with a plurality of elongated filter holes.

Preferably, a bracket is fixed on the inner wall of the filter tube, a plurality of propellers are axially connected on the bracket, and brushes are fixed on the edges of propeller blades.

Preferably, the shaft lining pipe is provided with a plurality of water replenishing holes.

The invention discloses the following technical effects: by arranging the shaft lining pipe in the second drilling hole and the water pumping pipe in the shaft lining pipe, when the water pumping pipe pumps water, the water stored between the shaft lining pipe and the water pumping pipe circulates downwards and heats the bottom of the shaft lining pipe, thereby increasing the temperature of underground water, discharging hot water from the water pumping pipe,

realizing the heat energy in the earth crust to be led out, solving the problem that geothermal energy is difficult to use at present, and having good popularization value.

BRIEF DESCRIPTION OF THE FIGURES In order to explain the embodiments of the present invention or the technical scheme in the prior art more clearly, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in the field, other drawings can be obtained according to these drawings without paying creative labor.

Fig. 1 is a schematic structural diagram of heat exchange tubes in geothermal wells; Fig. 2 is a schematic structural diagram of a pumping pipe; Fig. 3 is a schematic structural diagram of the centering ring; Fig. 4 is a schematic diagram of propeller installation; In the drawing: pump chamber pipe 1, shaft lining pipe 2, pumping pipe 3, first drilling hole 4, second drilling hole 5, first filling layer 6, first water stop ring 7, tray 8, second filling layer 9, second water stop ring 10, water inlet pipe 11, inner pipe 12, outer pipe 13, the insulating layer 14, thermal insulation layer 15, centering ring 16, water guide groove 17, filter tube 18, elongated filter holes 19, bracket 20, propellers 21, groove 22, roller 23.

DESCRIPTION OF THE INVENTION The technical scheme in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative labor belong to the scope of 5 protection of the present invention.

In order to make the above objects, features and advantages of the present invention more obvious and easy to understand, the present invention will be further explained in detail with reference to the drawings and specific embodiments.

The invention provides a heat exchange pipe in a geothermal well, which comprises a first drilling hole 4 through which a pump chamber pipe penetrates, a second drilling hole 5 at the bottom of which is located in the pump chamber pipe 1, and a shaft lining pipe 2 penetrating therein with a pumping pipe 3, the bottom of which is communicated with the shaft lining pipe 2, which is convenient for users.

A first filling layer 6 is filled between the first drilling hole 4 and the pump chamber pipe 1. A first water stop ring 7 is fixed between the second drilling hole 5 and the shaft lining pipe 2, A tray 8 is fixed on the top of the first water stop ring 7, and a second filling layer 9 is filled between the second drilling hole 5 and the shaft lining pipe 2. The second filling layer 9 is position on that top of the tray 8, a second water stop ring 10 is fixed between the shaft lining pipe 2 and the pumping pipe 3, a water inlet pipe 11 penetrates the second water stop ring 10.

A roller bit with a diameter of 445-450mm is used to drill to 200- 201 .4meters underground to form a first borehole 4, then, a pump chamber pipe 1 with a diameter of 320-340mm is lowered to the bottom end of the first drilling hole 4, and the pump chamber pipe 1 is kept higher than the ground.

Then, cement slurry with a specific gravity of 1.85 is pressed into the first filling layer 6 from the bottom end to the top end between the first drilling hole 4 and the pump chamber pipe 1 by using a high-pressure pumping method, and after waiting for the first filling layer 6 to solidify for 24 hours, a roller bit with a diameter of 210-216mm 1s used to drill to a depth of 2701-2701 20meters at the bottom of the well to form a second drilling hole 5. Then, a shaft lining pipe 2 with a diameter of 130-140mm is run in, and an expanded rubber water stop is installed between the second drilling hole 5 and the shaft lining pipe 2 as a water stop ring 7. The water stop ring 7 is located at 200.00-197 meters underground, the top of the water stop ring 7 is provided with a tray 8, and filling cement slurry is used as a second filling layer 9 from the top of the tray 8. A 70-73mm pumping pipe 3 is lowered into the shaft lining pipe 2, and a second water stop ring 10 is installed between the shaft lining pipe 2 and the pumping pipe 3. The second water stop ring 10 is provided with a hole through which a water inlet pipe 11 passes, or a plurality of water inlet pipes 11 can be arranged to enhance the water inflow.

Water enters the shaft lining pipe 2 from the water inlet pipe 11, absorbs geothermal energy at the bottom of the shaft lining pipe 2, and then returns to the ground from the pumping pipe 3 to bring out heat energy.

In a further optimization scheme, the pumping pipe 3 is a heat-insulating pipe, which comprises an inner pipe 12, an outer pipe 13 is sleeved outside the inner pipe 12, and a cavity between the inner pipe 12 and the outer pipe 13 is filled with a heat insulation layer.

The thermal insulation layer comprises a insulating layer 14 and a thermal insulation layer 15, wherein the thermal insulation layer 15 is made of rigid foam plastic and glass fiber cotton, the thermal insulation layer 15 insulates the low temperature outside the outer tube 13, the insulating layer 14 keeps the water temperature of the inner tube 12, and the outer tube 13 provides protection for the insulating layer 14 and the thermal insulation layer 15. The insulating layer 14 is located inside the thermal insulation layer 15. There is a water layer between the pumping pipe 3 and the shaft lining 2. The bottom temperature of the water layer is high and the top temperature is low.

During the rising process, the hot water in the pumping pipe 3 will contact with the water with lower temperature, which will lose heat.

After reaching the nozzle of the pumping pipe 3, the temperature will decrease, resulting in low utilization rate of heat energy.

However, the heat insulation layer 14 and 15 are arranged in the pumping pipe 3, which avoids the loss of heat energy in the water in the pumping pipe 3, greatly improves the heat preservation effect of the pumping pipe 3 and effectively improves the heat energy.

In a further optimization scheme, the pumping pipe 3 is pierced with a plurality of centering rings 16, the inner walls of which are fixedly connected with the pumping pipe 3, and the outer walls of the centering rings 16 are in contact with the well wall pipe 2 to prevent the pumping pipe 3 from inclining, and the outer walls of the centering rings 16 are provided with a plurality of water guiding grooves 17 to facilitate the water injected from the water inlet pipe

11 to flow downwards.

According to the further optimization scheme, grooves 22 are formed between the water guide grooves 17, and rollers 23 are axially connected in the grooves 22, so as to reduce the resistance between the centering ring 16 and the shaft lining pipe 2 and facilitate the insertion of the pumping pipe 3. An elastic layer (not shown in the figure) is laid outside the rollers 23 to prevent the rollers 23 from scratching the shaft lining pipe 2. According to the further optimization scheme, a filter tube 18 is fixed at the bottom end of the water inlet pipe 11, and a plurality of elongated filter holes 19 are formed on the pipe wall of the filter tube 18. The total cross-section of the elongated filter holes 19 is larger than that of the existing round holes, and the water flow capacity is large.

Compared with the round holes, the elongated filter holes 19 are less likely to be blocked by sand particles and have good water permeability, so the water output of geothermal wells is large.

In a further optimization scheme, a bracket 20 is fixed on the inner wall of the filter tube 18, and a plurality of propellers 21 are axially connected to the bracket 20, and brushes (not marked in the figure) are fixed on the blade edges of the propellers 21. The water flow from the filter tube 18 drives the propeller 21 to rotate, and the brush on the blade edge of the propeller 21 rotates with the propeller 21, so as to remove debris such as gravel from the elongated filter hole 19, prevent the elongated filter hole 19 from blocking and affecting the water inflow, and prevent debris such as gravel from entering the water pump at the top of the pumping pipe and causing the water pump to wear.

According to the further optimization scheme, the shaft lining pipe 2 is provided with a plurality of water replenishing holes (not marked in the figure),

and the water from the underground aquifer is introduced into the shaft lining pipe 2 to increase the water yield. The water replenishing holes are carried out from bottom to top, and the number of holes is determined according to the water temperature and water quantity.

According to the further optimization scheme, a reservoir (not marked in the figure) 1s arranged at the bottom of the shaft lining pipe 2, and the shaft lining pipe 2 is not used as a medium, so that the water directly contacts with the underground rock wall, so that the water temperature rises quickly and the heat transfer efficiency is enhanced.

In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner" and "outer" are based on those shown in the drawings, it is only for the convenience of describing the present invention, and does not indicate or imply that the referred devices or elements must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as limiting the present invention.

The above embodiments only describe the preferred mode of the invention, but do not limit the scope of the invention. On the premise of not departing from the design spirit of the invention, various modifications and improvements made by ordinary technicians in the field to the technical scheme of the invention shall fall within the protection scope determined by the claims of the invention.

The preferred embodiments of the invention are as follows:

A heat exchange pipe in geothermal well, characterized by comprising a first drilling hole (4), wherein a pump chamber pipe (1) penetrates through the first drilling hole (4), a second drilling hole (5) is arranged at the bottom of the first drilling hole (4), and the second drilling hole (5) is located in the pump chamber pipe (1), a shaft lining pipe (2) penetrates through the second drilling hole (5), and a pumping pipe (3) penetrates through the shaft lining pipe (2); A first filling layer (6) is filled between the first drilling hole (4) and the pump chamber pipe (1), a first water stop ring (7) is fixed between the second drilling hole (5) and the shaft lining pipe (2), a tray (8) is fixed on the top of the first water stop ring (7), a second filling layer (9) 1s filled between the second drilling hole (5) and the shaft lining pipe (2), the second filling layer (9) is located at the top of the tray (8), a second water stop ring (10) is fixed between the shaft lining pipe (2) and the pumping pipe (3), and a water inlet pipe (11) penetrates through the second water stop ring (10).

The heat exchange pipe in geothermal well according to the first embodiment, which is characterized in that the pumping pipe (3) is a thermal insulation pipe, which comprises an inner pipe (12), and an outer pipe (13) is sleeved outside the inner pipe (12). The cavity between the inner pipe (12) and the outer pipe (13) is filled with a thermal insulation layer, which comprises a insulating layer (14) and a thermal insulation layer (15), and the insulating layer (14) is located inside the thermal insulation layer (15).

The heat exchange pipe in geothermal well according to the first embodiment, which is characterized in that a plurality of centering rings (16) are pierced on the pumping pipe (3), the inner walls of the centering rings (16) are fixedly connected with the water pumping pipe (3), and the outer walls of the centering rings (16) are connected with the shaft lining pipe (2). The out wall of that centering rings (16) is provided with a plurality of water guide grooves (17).

The heat exchange pipe in geothermal well according to the previous embodiment, characterized in that grooves (22) are arranged between the water guide grooves (17), rollers (23) are axially connected in the grooves (22), and an elastic layer is laid outside the rollers (23).

The heat exchange pipe in geothermal well according to the first embodiment is characterized in that the bottom end of the water inlet pipe (11) is fixed with a filter tube (18).

The heat exchange pipe in geothermal well according to the previous embodiment is characterized in that the pipe wall of the filter tube (18) is provided with a plurality of elongated filter holes (19).

The heat exchange pipe in geothermal well according to the previous embodiment is characterized in that a bracket (20) is fixed on the inner wall of the filter tube (18), a plurality of propellers (21) are axially connected to the bracket (20), and brushes are fixed on the blade edges of the propellers (21).

The heat exchange pipe in geothermal well according to the first embodiment, which is characterized in that a plurality of water replenishing holes are formed on the shaft lining pipe (2).

Claims (8)

CONCLUSIONS A heat exchange pipe in a geothermal well, characterized by a first borehole (4), with a pump chamber pipe (1) penetrating through the first borehole (4), a second borehole (5) at the bottom of the first borehole (4 ) is placed and the second borehole (5) is in the pump room pipe (1), a shaft liner pipe (2) penetrates through the second borehole (5), and a pump pipe (3) penetrates the shaft liner pipe (2), in which between the first borehole (4) and the pump room pipe (1) a first filling layer (6) is filled, between the second borehole (5) and the shaft liner pipe (2) a first water stop ring (7) is fitted, on the top of the first water stop ring ( 7) a second filling layer (9) is filled between the second borehole (5) and the liner shaft pipe (2), the second filling layer (9) is at the top of the tray (8), a second water stop ring (10) is attached between the shaft lining pipe (2) and the pump pipe (3) and a water inlet pipe (11) penetrates the second water stop ring (10). The heat exchange pipe in a geothermal well according to claim 1, characterized in that the pump pipe (3) has a thermal insulation pipe 1s comprising an inner pipe (12) and an outer pipe (13) wrapped outside the inner pipe (12). ; wherein a cavity between the inner pipe (12) and the outer pipe (13) is filled with a thermal insulation layer, which consists of an insulating layer (14) and a thermal insulation layer (15), and the insulating layer (14) is inside the thermal insulation layer (15) is located. The geothermal well heat exchanger pipe according to claim 1, characterized in that a plurality of centering rings (16) on the pump pipe (3) are pierced, the inner walls of the centering rings (16) are fixedly connected to the water pump pipe (3), and the outer walls of the centering rings (16) are connected to the shaft liner pipe (2); wherein the outer walls of said centering rings (16) are provided with a plurality of water guiding grooves (17). The geothermal well heat exchange pipe according to claim 3, characterized in that grooves (22) are arranged between the water guiding grooves (17), rollers (23) are axially connected in the grooves (22), and an elastic layer outside the rolls are laid (23). The heat exchange pipe in a geothermal well according to claim 1, characterized in that the lower end of the water inlet pipe (11) is fixed with a filter tube (18). The geothermal well heat exchanger pipe according to claim 5 is characterized in that the pipe wall of the filter tube (18) is provided with a plurality of elongated filter holes (19). The heat exchanger pipe in a geothermal well according to claim 6, characterized in that a bracket (20) is fixed on the inner wall of the filter tube (18), a plurality of propellers (21) are axially connected to the bracket (20) and brushes attached to the blade edges of the propellers (21). The heat exchange pipe in a geothermal well according to claim 1, characterized in that a plurality of water filling holes are formed on the shaft lining pipe (2).