阅读说明：本技术 一种用于地热井上返段的双壁隔热取水管 (Double-wall heat-insulation water intake pipe for return section of geothermal well ) 是由 王林清 王艳丽 殷国乐 陈浩文 马汉臣 于 2021-10-13 设计创作，主要内容包括：本发明公开了一种用于地热井上返段的双壁隔热取水管,涉及地热开发技术领域,包括外管和设置于外管内的内管,内管内壁上固定贴合有内隔热层,内管外壁上固定贴合有外隔热层,外隔热层外表面与外管内壁之间存在间隙。本发明提供的用于地热井上返段的双壁隔热取水管,能够提高管道的隔热保温性能,降低热水在管道内向上输送时的热损失。(The invention discloses a double-wall heat-insulation water taking pipe for an upward return section of a geothermal well, and relates to the technical field of geothermal development. The double-wall heat-insulation water taking pipe for the return section of the geothermal well can improve the heat insulation performance of the pipeline and reduce the heat loss when hot water is conveyed upwards in the pipeline.)

1. A double-walled thermal-insulated water intaking pipe for geothermal well upstroke, characterized in that: the heat insulation pipe comprises an outer pipe and an inner pipe arranged in the outer pipe, wherein an inner heat insulation layer is fixedly attached to the inner wall of the inner pipe, an outer heat insulation layer is fixedly attached to the outer wall of the inner pipe, and a gap is formed between the outer surface of the outer heat insulation layer and the inner wall of the outer pipe.

2. A double-walled insulated water intake pipe for a geothermal uphole return section according to claim 1 wherein: the inner pipe is characterized by further comprising an upper heat insulation sleeve and a lower heat insulation sleeve, wherein the upper heat insulation sleeve and the lower heat insulation sleeve are respectively sleeved at the upper end and the lower end of the inner pipe and are respectively abutted against the inner wall of the outer pipe.

3. A double-walled insulated water intake pipe for a geothermal uphole return section according to claim 2 wherein: the inner tube includes body, male seal cover and female seal cover, the body both ends respectively with male seal cover with female seal cover seal fixed connection, adjacent two the inner tube, one the inner tube the male seal cover can seal the grafting in another the inner tube in the female seal cover, go up the heat insulating sleeve cover and locate outside the male seal cover, the heat insulating sleeve cover is located down outside the female seal cover.

4. A double-walled insulated water intake pipe for a geothermal uphole return section according to claim 3 wherein: the male seal cover is used for being inserted into the outer peripheral surface of one end in the female seal cover, an annular groove is formed in the outer peripheral surface of the one end in the female seal cover, a seal ring is arranged in the annular groove, and the male seal cover and the female seal cover which are connected in an inserting mode are connected in a sealing mode through the seal ring in a sealing mode.

5. A double-walled insulated water intake pipe for a geothermal uphole return section according to claim 1 wherein: the two ends of the outer pipe are respectively provided with a female connecting sleeve and a male connecting sleeve, the male connecting sleeve of one outer pipe can be in threaded connection with the female connecting sleeve of the other outer pipe.

6. A double-walled insulated water intake pipe for a geothermal uphole return section according to claim 3 wherein: the male sealing sleeve is characterized in that an annular limiting protrusion is arranged on the outer peripheral surface of the male sealing sleeve, the annular limiting protrusion comprises a bearing part with an inverted conical surface on the outer peripheral surface, the inner surface of the outer tube is provided with an inverted conical bearing surface corresponding to the bearing part, the upper heat insulation sleeve comprises a heat insulation bearing part, the heat insulation bearing part is connected to the outer peripheral surface of the bearing part and between the inverted conical bearing surfaces in a matched mode, and the inner surface and the outer surface of the heat insulation bearing part are respectively in contact with the outer peripheral surface of the bearing part and the inverted conical bearing surface.

7. A double-walled insulated water intake pipe for a geothermal uphole return section according to claim 6 wherein: go up the radiation shield cover still include with thermal-insulated supporting part fixed connection's spacing portion, spacing internal surface is equipped with first spacing recess, be equipped with first spacing retaining ring in the first spacing recess, first spacing retaining ring can be right the spacing protruding formation of annular blocks the messenger annular spacing protruding can not upwards break away from go up the radiation shield cover, the outer tube internal surface is equipped with the spacing recess of second, be equipped with the spacing retaining ring of second in the spacing recess of second, the spacing retaining ring of second can be right spacing portion forms blocks the messenger go up the radiation shield cover can not upwards break away from the back taper loading end.

8. A double-walled insulated water intake pipe for a geothermal uphole return section according to claim 1 wherein: the inner heat-insulating layer is formed by lining a polyethylene pipe in the inner pipe, and the outer heat-insulating layer is formed by coating a binder on the outer wall of the inner pipe and spraying SiO₂Aerogel powder formation.

9. A double-walled insulated water intake pipe for a geothermal uphole return section according to claim 2 wherein: the upper heat insulation sleeve and the lower heat insulation sleeve are made of polytetrafluoroethylene materials.

10. A double-walled insulated water intake pipe for a geothermal uphole return section according to claim 3 wherein: the body is seamless steel pipe, male seal cover with female seal cover is 35CrMo material preparation and forms, the body with male seal cover with female seal cover welded fastening connects.

Technical Field

The invention relates to the technical field of geothermal development, in particular to a double-wall heat-insulation water taking pipe for an upward return section of a geothermal well.

Background

The geothermal energy is a novel clean and environment-friendly renewable energy source, and the active development and utilization of the geothermal energy has important practical significance and long-term strategic significance for relieving energy resource pressure, realizing non-fossil energy targets, promoting energy production and consumption revolution and promoting ecological civilization construction.

The current utilization mode of the geothermal energy of the middle and deep layers is mainly a pumping and filling type underground water system, the pumping and filling type underground water system circularly takes heat through drilling a production well and a recharging well, and the use of the pumping and filling type underground water system has many limitations, for example, a geothermal exploitation and utilization area is required to have abundant underground hot water resources; in a part of pore type heat storage areas, the geothermal tail water recharging effect is not ideal all the time, and tiny impurities in the recharging water can block the gaps of the geothermal well rock stratum, so that recharging cannot be carried out, which is a main factor for restricting the development and utilization of geothermal resources of a pumping and recharging type underground water system; if the soil is not recharged, the underground water level is reduced, the ground surface is sunk, and the soil is salinized; in urban building dense areas, the well drilling position is also an important factor for restricting geothermal development. Based on the defects of the pumping and filling type underground water system, the development of a new geothermal development mode becomes a necessary way for popularizing the utilization of geothermal energy.

A geothermal well single-well injection-production closed heat extraction system only needs to drill a geothermal well, after cement is adopted for cementing, a water extraction pipeline is connected and is put into a preset position of the geothermal well, circulating medium (cold water) is injected through an annular space between the water extraction pipeline and the geothermal well, the circulating medium (cold water) is heated from a geothermal reservoir after reaching the preset position and then enters an inner pipe of the water extraction pipeline and returns to a ground heat exchanger, so that heat extraction of geothermal development is realized in a real sense without water extraction, the requirement on geothermal resources is low, the problems that the formation is blocked by tail water recharge are avoided, and the system has a wide market application prospect. Because the medium of recharging is injected from the annular space between the pipeline and the drill hole, the injected temperature is normal temperature, and the geothermal water taken out is output from the center of the pipeline, if a conventional hot water taking pipe is used, only one layer of pipe wall is separated, the hot water in the pipe can exchange heat with the cold water outside the pipe, so that the temperature of the water in the pipe is reduced, and a novel double-layer heat taking heat preservation pipe is needed to reduce the heat loss of the water after heat exchange after being taken to the ground from an underground reservoir stratum.

Disclosure of Invention

The invention aims to provide a double-wall heat-insulation water taking pipe for an upward return section of a geothermal well, which is used for solving the problems in the prior art, improving the heat insulation performance of a pipeline and reducing the heat loss when hot water is conveyed upwards in the pipeline.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a double-wall heat-insulation water intake pipe for an upward return section of a geothermal well, which comprises an outer pipe and an inner pipe arranged in the outer pipe, wherein an inner heat-insulation layer is fixedly attached to the inner wall of the inner pipe, an outer heat-insulation layer is fixedly attached to the outer wall of the inner pipe, and a gap is formed between the outer surface of the outer heat-insulation layer and the inner wall of the outer pipe.

Preferably, the heat pipe further comprises an upper heat insulation sleeve and a lower heat insulation sleeve, wherein the upper heat insulation sleeve and the lower heat insulation sleeve are respectively sleeved at the upper end and the lower end of the inner pipe and are respectively abutted against the inner wall of the outer pipe.

Preferably, the inner tube includes body, male seal cover and female seal cover, the body both ends respectively with male seal cover with female seal cover seal fixed connection, adjacent two the inner tube, one the inner tube the male seal cover can seal the grafting in another the inner tube in the female seal cover, go up the heat insulating sleeve cover and locate outside the male seal cover, the heat insulating sleeve cover is located down outside the female seal cover.

Preferably, the male seal cover is used for being inserted into the outer peripheral surface of one end in the female seal cover, an annular groove is formed in the outer peripheral surface of the one end, a seal ring is arranged in the annular groove, and the male seal cover and the female seal cover which are connected in an inserting mode are connected in a sealing mode through the seal ring in a sealing mode.

Preferably, the two ends of the outer pipe are respectively provided with a female connecting sleeve and a male connecting sleeve, the male connecting sleeve of one outer pipe can be in threaded connection with the female connecting sleeve of the other outer pipe.

Preferably, the outer peripheral surface of the male sealing sleeve is provided with an annular limiting protrusion, the annular limiting protrusion comprises a bearing part with an inverted conical outer peripheral surface, the inner surface of the outer tube is provided with an inverted conical bearing surface corresponding to the bearing part, the upper heat insulation sleeve comprises a heat insulation bearing part, the heat insulation bearing part is connected between the outer peripheral surface of the bearing part and the inverted conical bearing surface in a matched manner, and the inner surface and the outer surface of the heat insulation bearing part are respectively in contact with the outer peripheral surface of the bearing part and the inverted conical bearing surface.

Preferably, go up the radiation shield and still include with thermal-insulated supporting part fixed connection's spacing portion, spacing internal surface is equipped with first spacing recess, be equipped with first spacing retaining ring in the first spacing recess, first spacing retaining ring can be right annular spacing protruding formation blocks the messenger annular spacing protruding can not upwards break away from go up the radiation shield, the outer tube internal surface is equipped with the spacing recess of second, be equipped with the spacing retaining ring of second in the spacing recess of second, the spacing retaining ring of second can be right spacing portion formation blocks the messenger go up the radiation shield can not upwards break away from the back taper loading end.

Preferably, the inner heat insulation layer is formed by lining a polyethylene pipe in the inner pipe, and the outer heat insulation layer is formed by coating a binder on the outer wall of the inner pipe and spraying SiO₂Aerogel powder formation.

Preferably, the upper heat insulation sleeve and the lower heat insulation sleeve are made of polytetrafluoroethylene materials.

Preferably, the body is seamless steel pipe, male seal cover with female seal cover is 35CrMo material preparation and forms, the body with male seal cover with female seal cover welded fastening connects.

Compared with the prior art, the invention has the following technical effects:

according to the double-wall heat-insulation water taking pipe for the upward return section of the geothermal well, after heat exchange is carried out on a circulating medium in a high-temperature area at the middle lower part of the geothermal well, when the circulating medium returns to the ground heat exchanger from the central channel of the inner pipe, the inner heat-insulation layer and the outer heat-insulation layer are arranged, so that the heat insulation performance of the inner pipe is improved, air is arranged in a gap between the outer surface of the outer heat-insulation layer and the inner wall of the outer pipe, the air is a poor heat conductor, and the heat is further reduced from being transferred to the outer pipe from the inner pipe, so that the heat insulation performance of the pipeline is improved, and the heat loss of hot water during upward conveying in the pipeline is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic structural view of a double-walled insulated water intake pipe for a return section of a geothermal well according to the present invention;

FIG. 2 is an enlarged fragmentary view of section I of the double-walled insulated water intake line of FIG. 1 for a return section of a geothermal well;

FIG. 3 is a cross-sectional view of an upper insulating jacket in a double-walled insulated water intake pipe for an uphole return section of a geothermal well provided in accordance with the present invention;

FIG. 4 is a cross-sectional view of the lower insulating jacket in a double-walled insulated water riser for a geothermal uphole section provided in accordance with the present invention;

FIG. 5 is a schematic structural view of the interconnection of double-walled insulated water intake pipes for a return section of a geothermal well according to the present invention;

FIG. 6 is an enlarged partial view of section II of FIG. 5;

FIG. 7 is a schematic structural diagram of single-well heat extraction of a geothermal well by using a double-wall heat-insulating water extraction pipe for an upward return section of the geothermal well, provided by the invention;

in the figure: 100-double-wall heat-insulation water taking pipe for upward return section of geothermal well, 1-outer pipe, 2-inner pipe, 3-inner heat-insulation layer, 4-outer heat-insulation layer, 5-upper heat-insulation sleeve, 6-lower heat-insulation sleeve, 7-pipe body, 8-male seal sleeve, 9-female seal sleeve, 10-annular groove, 11-seal ring, 12-female seal sleeve, 13-male seal sleeve, 14-annular limiting protrusion, 15-bearing part, 16-inverted conical bearing surface, 17-heat-insulation bearing part, 18-limiting part, 19-first limiting groove, 20-first limiting check ring, 21-second limiting groove, 22-second limiting check ring, 23-water filtering pipe, 24-orifice equipment, 25-circulating medium processing equipment, 26-heat exchanger, 26-water filter, 27-pump, 28-user end, 29-annulus, 30-geothermal reservoir, 31-heat exchange section and 32-upward return section.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide a double-wall heat-insulation water taking pipe for an upward return section of a geothermal well, which is used for solving the problems in the prior art, improving the heat insulation performance of a pipeline and reducing the heat loss when hot water is conveyed upwards in the pipeline.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1 and 7, the present embodiment provides a double-walled heat-insulating water intake pipe 100 for an upward return section of a geothermal well, which includes an outer pipe 1 and an inner pipe 2 disposed in the outer pipe 1, wherein an inner heat-insulating layer 3 is fixedly attached to an inner wall of the inner pipe 2, an outer heat-insulating layer 4 is fixedly attached to an outer wall of the inner pipe 2, and a gap exists between an outer surface of the outer heat-insulating layer 4 and an inner wall of the outer pipe 1.

When the heat insulation device is used, after heat exchange of a circulating medium occurs in a high-temperature area at the middle lower part of the geothermal well, namely a geothermal reservoir 30, and the circulating medium returns to the ground heat exchanger 26 from the central channel of the inner pipe 2, the arrangement of the inner heat insulation layer 3 and the outer heat insulation layer 4 improves the heat insulation performance of the inner pipe 2, and a gap (air in the gap is a poor heat conductor) between the outer surface of the outer heat insulation layer 4 and the inner wall of the outer pipe 1 further reduces heat transfer from the inner pipe 2 to the outer pipe 1, so that the heat insulation performance of a pipeline is improved, and the heat loss when hot water is conveyed upwards in the pipeline is reduced.

As shown in fig. 1-4, in this embodiment, the heat pipe further includes an upper heat insulating sleeve 5 and a lower heat insulating sleeve 6, and the upper heat insulating sleeve 5 and the lower heat insulating sleeve 6 are respectively sleeved on the upper end and the lower end of the inner pipe 2 and are both abutted against the inner wall of the outer pipe 1. The radial relative position between the inner pipe 2 and the outer pipe 1 can be ensured by the upper and lower heat insulating sleeves 5 and 6, and the heat transfer caused by the direct contact between the outer heat insulating layer 4 outside the inner pipe 2 and the outer pipe 1 is prevented.

As shown in fig. 1-2 and 5-6, in this embodiment, the inner tube 2 includes a tube body 7, a male sealing sleeve 8 and a female sealing sleeve 9, two ends of the tube body 7 are respectively fixedly connected to the male sealing sleeve 8 and the female sealing sleeve 9 in a sealing manner, two adjacent inner tubes 2, the male sealing sleeve 8 of one inner tube 2 can be inserted into the female sealing sleeve 9 of the other inner tube 2 in a sealing manner, the upper heat insulation sleeve 5 is sleeved outside the male sealing sleeve 8, and the lower heat insulation sleeve 6 is sleeved outside the female sealing sleeve 9, so that the inner tubes 2 can be conveniently detached and installed, and can be used for multiple times.

As shown in fig. 1 and 6, in this embodiment, an annular groove 10 is provided on an outer peripheral surface of one end of the male sealing sleeve 8, which is inserted into the female sealing sleeve 9, a sealing ring 11 is provided in the annular groove 10, the male sealing sleeve 8 and the female sealing sleeve 9 are connected in an inserting manner through the sealing ring 11, wherein two annular grooves 10 are provided, the two annular grooves 10 are arranged at intervals, one sealing ring 11 is provided in each annular groove 10, and the sealing ring 11 is an O-shaped sealing ring, so that the sealing effect is better.

As shown in fig. 1 and fig. 6, in this embodiment, the female connection sleeves 12 and the male connection sleeves 13 are respectively disposed at two ends of the outer tubes 1, and the male connection sleeve 13 of one outer tube 1 can be in threaded connection with the female connection sleeve 12 of another outer tube 1 of two adjacent outer tubes 1, so that the connection is convenient and the disassembly is convenient.

As shown in fig. 2-3, in the present embodiment, an annular limiting protrusion 14 is disposed on the outer peripheral surface of the male sealing boot 8, the annular limiting protrusion 14 includes a bearing portion 15 with an inverted conical outer peripheral surface, an inverted conical bearing surface 16 corresponding to the bearing portion 15 is disposed on the inner surface of the outer tube 1, the upper heat insulating boot 5 includes a heat insulating bearing portion 17, the heat insulating bearing portion 17 is connected between the outer peripheral surface of the bearing portion 15 and the inverted conical bearing surface 16 in a matching manner, and the inner surface and the outer surface of the heat insulating bearing portion 17 are respectively in contact with the outer peripheral surface of the bearing portion 15 and the inverted conical bearing surface 16. The receiving portion 15 of the inner pipe 2 is received on the inverted-conical receiving surface 16 in the outer pipe 1 via the heat insulating receiving portion 17 of the upper heat insulating jacket 5, and functions to support the inner pipe 2.

As shown in fig. 2-3, in this embodiment, the upper heat insulating sleeve 5 further includes a limiting portion 18 fixedly connected to the heat insulating bearing portion 17, a first limiting groove 19 is disposed on an inner surface of the limiting portion 18, a first limiting retaining ring 20 is disposed in the first limiting groove 19, the first limiting retaining ring 20 can block the annular limiting protrusion 14 so that the annular limiting protrusion 14 cannot be separated from the upper heat insulating sleeve 5 upwards, a second limiting groove 21 is disposed on an inner surface of the outer tube 1, a second limiting retaining ring 22 is disposed in the second limiting groove 21, and the second limiting retaining ring 22 can block the limiting portion 18 so that the upper heat insulating sleeve 5 cannot be separated from the inverted cone-shaped bearing surface 16 upwards, so as to limit the inner tube 2 in the outer tube 1 and ensure that a relative position between the inner tube 2 and the outer tube 1 remains unchanged.

In this embodiment, the inner thermal insulation layer 3 is formed by lining a polyethylene pipe inside the inner pipe 2, and the outer thermal insulation layer 4 is formed by coating a binder on the outer wall of the inner pipe 2 and spraying SiO₂Aerogel powder formation. The provision of the polyethylene pipe not only improves the heat insulating performance of the inner pipe 2, but also has good corrosion resistance when transmitting a high-temperature circulating medium. The manufacturing process of the outer heat insulation layer 4 comprises the following steps: firstly, coating metal binder on the outer wall of the inner tube 2, and then spraying SiO₂Aerogel powder onto the metal binder to form SiO₂After the aerogel powder completely covers the outer wall of the inner pipe, the metal adhesive is coated, and then the SiO is sprayed₂Aerogel powder is coated on the metal binder, and the steps are repeated until SiO is achieved₂A predetermined thickness of aerogel.

In this embodiment, the upper heat insulating sleeve 5 and the lower heat insulating sleeve 6 are made of polytetrafluoroethylene, and have good heat insulating effect and high temperature resistance.

In this embodiment, body 7 is seamless steel pipe, and male seal cover 8 and female seal cover 9 are the preparation of 35CrMo material and form, and body 7 and male seal cover 8 and female seal cover 9 welded fastening are connected, and wherein, outer tube 1 adopts the oil standard drilling rod, and the structure is reliable, compares conventional PVC pipe life and improves greatly to for almost being disposable conventional PVC pipe, this intake pipe can realize many mouthfuls of wells long-time use many times.

As shown in figure 7, the invention is suitable for a single-well geothermal well in a middle-deep layer, the water taking pipe column is composed of a plurality of double-wall heat-insulating water taking pipes 100 which are connected end to end and used for the upward return section of the geothermal well, and a water filter pipe 23 (floral pipe) which is connected with the lowest end and used for the double-wall heat-insulating water taking pipe 100 of the upward return section of the geothermal well, through orifice device 24 with water intaking tubular column upper end be fixed in geothermal well head, the length and the depth of transferring of strainer 23 should be unanimous with geothermal reservoir 30 (geothermal well circulation medium heat transfer stratum) zone span, the water intaking tubular column includes heat transfer section 31 and upward returns the section 32, heat transfer section 31 is the pipeline section that strainer 23 constitutes, upward returns the section and is the pipeline section between strainer 23 upper end to the ground in the water intaking tubular column, this device mainly used cycle medium after rising temperature upward returns the transmission stage, upward returns the section promptly and comprises a plurality of double-walled heat insulation water intaking pipes 100 that are used for geothermal well upward returning the section. The heat taking mode is that a water taking pipe column is lowered to a preset position, a circulating medium is injected through an annular space 29 between the water taking pipe column and a well wall under the action of a pump 27 until reaching a high-temperature area (namely a heat exchange stratum area), the circulating medium exchanges heat in the high-temperature area at the middle lower part of a geothermal well, enters through a water filter pipe 23 and returns to a ground circulating medium processing device 25 from a central channel (a central channel of an inner pipe 2) of the water taking pipe, enters into a heat exchanger 26 after being processed by the circulating medium processing device 25, and is conveyed into the annular space 29 through the pump 27 after exchanging heat with a user side 28 at the heat exchanger 26. The circulating medium traveling route is as follows: ground-annulus-water filter pipe-double-wall heat-insulation water intake pipe-ground. The invention can ensure that when the heated circulating medium returns upwards through the central channel of the device, the heat transfer is isolated by multilayer heat insulation measures such as the inner pipe, the inner heat insulation layer, the outer heat insulation layer, the air in the gap, the outer pipe and the like, thereby reducing the heat loss to the maximum extent.

The principle and the implementation mode of the invention are explained by applying a specific example, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.