Middle-deep geothermal well connecting device

Abstract

The utility model relates to a middle-deep geothermal well connecting device which comprises a reducer pipe, a water inlet pipe and a water outlet pipe, the lower end of the reducer pipe is in through connection with an oil casing arranged in a stratum, a heat exchange inner pipe is annularly sleeved in the oil casing in a clearance mode, and the upper end of the heat exchange inner pipe at least extends to the upper end of the reducer pipe. The periphery of the reducer pipe and the inner periphery of the heat exchange inner pipe form an annular cavity, the water inlet pipe and the water outlet pipe are arranged at the upper end of the reducer pipe, the water outlet pipe is communicated with the heat exchange inner pipe, and the water inlet pipe is communicated with the annular cavity. The water outlet pipe and the water inlet pipe are vertically arranged on the upper portion of the reducer pipe and extend upwards, and therefore when the well connecting device is in a working state, gas accumulation cannot be generated in the reducer pipe, and operation of a heat pump system cannot be affected.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of middle-deep geothermal energy heating, and particularly relates to a middle-deep geothermal well connecting device. BACKGROUND

[0002] The middle-deep geothermal geoburied pipe heating technology refers to drilling a hole to a depth of 2-3 km underground by a drilling machine, installing a connecting device at the upper end of the hole, installing a bottom-closed petroleum casing and a heat exchange inner pipe in the hole, forming a coaxial casing by having the heat exchange inner pipe gap annularly sleeved on the petroleum casing, forming an annular gap between the petroleum casing and the heat exchange inner pipe, having water medium flow into the annular gap from the connecting device to absorb stratum heat underground, opening a hole at the bottom end of the heat exchange inner pipe to make the water medium flow through the heat exchange inner pipe to take out underground heat to the ground, and having the hot water medium returned to the ground heat exchanged according to the temperature requirement of user load or heated by a heat pump system before being supplied to the user end.

[0003] In the two connecting devices currently used, the petroleum casing and the heat exchange inner pipe are coaxially arranged in the inner cavity of the connecting pipe of the connecting device, wherein the water inlet pipe of the first connecting device horizontally penetrates the inner cavity lower end of the connecting pipe, a large amount of gas is generated in the space of the upper end of the inner cavity of the connecting pipe during operation, the gas is easy to accumulate to form gas blockage to affect the flow of the pipeline system, the gas is discharged through the manual exhaust valve arranged on the outer periphery of the upper end of the inner cavity of the connecting pipe, and since the accumulation degree of the gas in the inner cavity of the connecting pipe is unknown, the excess gas can only be manually discharged by observing the flow change of the pipeline, which is inconvenient to operate and the gas still accumulates in the inner cavity of the connecting pipe.

[0004] In order to overcome the disadvantages of manual exhaust, the water outlet pipe and the water inlet pipe of the second connecting device horizontally penetrate the upper and lower ends of the inner cavity of the connecting pipe respectively, and an automatic exhaust valve is arranged on the top of the connecting pipe to discharge the gas, which can overcome the gas accumulation problem to a certain extent, but since the automatic exhaust valve can only be used to discharge the gas exceeding the preset pressure, the gas still exists in the inner cavity of the connecting pipe.

[0005] Meanwhile, since the connecting device is installed on the underground inspection well, the inspection well is in a high-temperature and high-humidity environment all the year round and has a great depth, and the heat exchange inner pipe of the connecting device is installed in the inner cavity of the connecting pipe, if the connection is not sealed well or leakage occurs during use, it is difficult to be found, and when maintenance is needed, the large flange on the upper part of the connecting pipe needs to be opened for maintenance, which is difficult and time-consuming, and especially has a great safety risk when construction is carried out in a relatively closed underground space. UTILITY MODEL CONTENTS

[0006] In order to solve the above technical problems, the utility model discloses a purpose at providing a kind of middle-deep geothermal well connects well device, water inlet and water outlet adopt vertical eccentric ring sleeve mode, water outlet pipe and water inlet pipe are vertically arranged on the inner cavity upper end of water receiving device, when inner cavity does not produce gas accumulation in working condition, it is convenient and fast to maintain overhaul simultaneously.

[0007] To achieve the above object, the utility model takes the following technical scheme:

[0008] A kind of middle-deep geothermal well connects well device, including reducing pipe, water inlet pipe and water outlet pipe, the lower end of the reducing pipe is connected with the oil casing pipe arranged in stratum, the oil casing pipe is annularly sleeved with heat exchange inner tube, the upper end of the heat exchange inner tube at least extends to the upper end of the reducing pipe, the outer periphery of the reducing pipe and the inner periphery of the heat exchange inner tube form annular cavity, the water inlet pipe and the water outlet pipe are arranged in the upper end of the reducing pipe, wherein the water outlet pipe is connected with the heat exchange inner tube, and the water inlet pipe is connected with the annular cavity.

[0009] Further, the upper end of the reducing pipe is provided with a cover flange, the water inlet pipe is connected to the upper end of the cover flange, and the heat exchange inner tube extends out of the cover flange and is connected with the water outlet pipe.

[0010] Further, the reducing pipe is an eccentric reducing joint.

[0011] Further, the reducing pipe includes an eccentric reducing joint and an extension pipe, the lower end of the eccentric reducing joint is connected with the oil casing pipe, the upper end of the eccentric reducing joint is connected with the extension pipe, and the upper end of the extension pipe is provided with the cover flange.

[0012] Further, the heat exchange inner tube is fixed to the cover flange through a T-shaped joint and is connected with the water outlet pipe.

[0013] Further, the cover flange is provided with a groove, a sealing ring is embedded in the groove, and the lower end face of the T-shaped joint abuts on the sealing ring.

[0014] Further, the lower end of the water outlet pipe is provided with a crimping flange, and the water outlet pipe is connected to the T-shaped joint through the crimping flange.

[0015] Further, the eccentric reducing joint is a pipe cylinder, the inner diameters of the two ends of the pipe cylinder are different, and the axis of one end deviates from the axis of the other end.

[0016] Further, the upper end of the water inlet pipe and the upper end of the water outlet pipe are both arc-shaped pipes, and the lower end of the water inlet pipe and the lower end of the water outlet pipe are both vertical pipes.

[0017] Further, the sealing ring is a silica gel sealing ring.

[0018] The utility model discloses a following technical scheme has the following advantages and effects.

[0019] (1) the utility model provides a kind of middle-deep geothermal well interface device, interface device uses " upper inlet upper outlet, eccentric heat exchange inner tube, water inlet water outlet same cavity " structural mode, i.e. water outlet pipe, return pipe is vertically installed on the upper end of reducing pipe, heat exchange inner tube is arranged in reducing pipe using eccentric mode, so interface device does not produce gas accumulation inside when working state, need not set up exhaust and drainage device, also can not form air block and affect heat pump system operation, improve the system stability of heat pump.

[0020] (2) the utility model provides a kind of middle-deep geothermal well interface device, since the connecting point of return pipe and water outlet pipe is located at the upper end outside of reducing pipe, when leakage occurs or needs to replace heat exchange inner tube, it is convenient to maintain and repair, especially inspection well is generally located at the depth of two or three meters underground, perennial high temperature, high humidity, the exhaust valve, drainage valve of original interface device is prone to failure, the utility model does not need exhaust and drainage, and the workload of maintenance and repair is reduced, and the risk of operation in the limited space of inspection well chamber is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 For the structure diagram of prior art interface device Figure 1 .

[0022] Figure 2 For the structure diagram of prior art interface device Figure 2 .

[0023] Figure 3 For the structure diagram of the interface device of the utility model.

[0024] Figure 4 For the enlarged structure diagram of A of Figure 3 .

[0025] The name of the utility model's reference signs is as follows:

[0026] 1-inlet pipe;2-cover flange;3-reducing pipe;031- eccentric reducing joint;032- extension pipe;4-heat exchange inner tube;5-T joint;6-pressing flange;7-outlet pipe;8-sealing ring;9-hand exhaust valve, 10- interface pipe;11-automatic exhaust valve;12-flange pipe. DETAILED DESCRIPTION

[0027] The embodiment of the utility model will be described in detail below in combination with the drawings, so that the purpose, characteristics and advantages of the utility model can be more clearly understood.It should be understood that the embodiment shown in the drawings is not a limitation on the scope of the utility model, but only to illustrate the essential spirit of the technical scheme of the utility model.

[0028] As shown in Figure 1 One of the existing well junction devices, the upper end of the heat exchange inner tube 4 is coaxially and gapingly sleeved in the well junction pipe 10, the lower end of the well junction pipe 10 is connected with the oil casing pipe, the flange pipe 12 is connected with the oil casing pipe through the upper end of the well junction pipe, the water outlet pipe 7 is connected with the flange pipe 12 through the flange, and the one end of the water inlet pipe 1 is horizontally connected with the inner cavity of the lower end of the well junction pipe, and the manual exhaust valve 9 is arranged on the outer periphery of the upper end of the well junction pipe.

[0029] As shown in Figure 2 Another of the existing well junction devices, the well junction pipe 10 is composed of two parts connected through the flange pipe, the upper end of the heat exchange inner tube 4 is coaxially and gapingly sleeved in the lower end of the well junction pipe, the lower end of the lower end of the well junction pipe is connected with the oil casing pipe, the lower end of the flange pipe 12 is connected with the upper end of the oil casing pipe and located in the inner cavity of the lower end of the well junction pipe 10, the manual exhaust valve 9 is arranged on the radial outer periphery of the upper end of the well junction pipe, the automatic exhaust valve 11 is arranged on the top of the well junction pipe, and the one end of the water outlet pipe 7 is horizontally connected with the upper end of the well junction pipe, and the one end of the water inlet pipe 1 is horizontally connected with the lower end of the well junction pipe.

[0030] As shown in Figure 3 The utility model provides a kind of well junction device of middle deep geothermal well, including reducing pipe 3, water inlet pipe 1 and water outlet pipe 7, the lower end of reducing pipe 3 is connected with the oil casing pipe being arranged in stratum, and the oil casing pipe is gapingly sleeved with heat exchange inner tube 4, the upper end of heat exchange inner tube 4 at least extends to the upper end of reducing pipe 3, and the outer periphery of reducing pipe 3 and the inner periphery of heat exchange inner tube 4 form annular cavity, water inlet pipe 1 and water outlet pipe 7 are vertically arranged in the upper end of reducing pipe 3, wherein, water outlet pipe 7 is connected with heat exchange inner tube 4, and water inlet pipe 1 is connected with annular cavity.

[0031] Specifically, reducing pipe 3 is eccentric reducing joint 031, one end of eccentric reducing joint 031 is larger in diameter, the other end is smaller in diameter, water inlet pipe 1 and water outlet pipe 7 are vertically arranged in the larger end, and the smaller end of eccentric reducing joint 031 is welded and connected with the upper end of oil casing pipe. Heat exchange inner tube 4 is coaxially sleeved in oil casing pipe, and upper end extends out of the upper end of eccentric reducing joint 031, and heat exchange inner tube 4 is eccentrically sleeved with eccentric reducing joint 031. The annular cavity formed between heat exchange inner tube 4 and eccentric reducing joint 031 is connected with the annular cavity formed between heat exchange inner tube 4 and oil casing pipe, so that the water outlet pipe 7 of well junction device extends upward in the upper part of cavity, so that the well junction device does not generate gas accumulation in the internal when working.

[0032] Further, in order to facilitate the installation of the heat exchange inner tube 4, the upper end of the reducing pipe 3 is provided with a cover flange 2, and the water inlet pipe 1 is connected to the upper end of the cover flange 2. The heat exchange inner tube 4 extends out of the cover flange 2 and is connected to the water inlet pipe 1.

[0033] Specifically, the cover flange 2 is provided with a water inlet hole and a water outlet hole. The water inlet pipe 1 is connected to the upper end of the water inlet hole, and the heat exchange inner tube 4 extends out of the water outlet hole and is connected to the water outlet pipe 7. Since the cover flange 2 is outside the upper end of the reducing pipe 3, it is easy to check and find the leakage point, and the maintenance and replacement are convenient and the workload is small.

[0034] Further, in order to further improve the water inlet space of the reducing pipe 3, the reducing pipe 3 comprises an eccentric reducing joint 031 and an extension pipe 032. The lower end of the eccentric reducing joint 031 is connected to the petroleum casing pipe, and the upper end of the eccentric reducing joint 031 is connected to the extension pipe. The upper end of the extension pipe 032 is provided with a cover flange 2.

[0035] Specifically, the extension pipe 032 is a cylindrical pipe, and the cross-sectional shape of the cylindrical pipe is the same as the cross-sectional shape of the larger opening end of the eccentric reducing joint 031. One end of the extension pipe 032 and the larger opening end of the eccentric reducing joint 031 are connected as one body, and the other end of the extension pipe 032 is provided with a flange. The cover flange 2 is connected to the flange.

[0036] Further, the eccentric reducing joint 031 is a pipe cylinder, and the inner diameters of the openings at both ends of the pipe cylinder are different. The axis of one end opening deviates from the axis of the other end opening.

[0037] Specifically, the openings at the upper and lower ends of the eccentric reducing joint 031 are circular openings, and the axial cross section of the eccentric reducing joint 031 is a quadrilateral structure. The opposite first side and third side of the quadrilateral structure are parallel to each other and have different lengths, so that the axes of the circular openings at the upper and lower ends are not on the same axis. The eccentric reducing joint 031 facilitates the gradual transition of the water medium into the petroleum casing pipe.

[0038] As a preferred, the opposite first side and third side of the quadrilateral structure are parallel to each other, the extension lines of the opposite second side and fourth side of the quadrilateral structure intersect, and the second side is perpendicular to the first side and the third side. The fourth side is a straight line or a curve. When the fourth side is a straight line, the quadrilateral structure is a right trapezoid.

[0039] Further, the heat exchange inner tube 4 is connected to the cover flange 2 and the water outlet pipe 7 through a T-shaped joint 5.

[0040] Specifically, the outer periphery of the T-shaped joint 5 is fixed on the cover flange 2, the heat exchange inner tube 4 is nested in one end of the T-shaped joint 5, and the lower end of the water outlet pipe 7 is provided with a crimping flange 6. The water outlet pipe 7 is connected to the T-shaped joint 5 through the crimping flange 6.

[0041] As shown in the drawings. Further, the cover flange 2 is provided with a groove, and a sealing ring 8 is embedded in the groove, and the lower end face of the T-shaped joint 5 is resisted on the sealing ring 8. The sealing ring 8 is a silica gel sealing ring made of silica gel material. Figure 4

[0042] Specifically, a sunken groove is processed on the outer edge of the water outlet hole of the cover flange 2, the T-shaped joint 5 and the sealing ring 8 are installed in the groove, and the T-shaped joint 5 and the sealing ring 8 can effectively prevent water leakage and facilitate visual observation of leakage.

[0043] Further, in order to facilitate water inlet and outlet, the upper end of the water inlet pipe 1 and the upper end of the water outlet pipe 7 are arc-shaped pipes, and the lower end of the water inlet pipe 1 and the lower end of the water outlet pipe 7 are vertical pipes. The arc-shaped pipe of the water inlet pipe 1 or the water outlet pipe 7 is connected through the corresponding vertical pipe, one end of the vertical pipe is located on one side of the reducing pipe, and one end of the arc-shaped pipe is connected to the user end.

[0044] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.​

Claims

1. A well connection device for medium-deep geothermal wells, characterized in that, The system includes a reducing pipe (3), an inlet pipe (1), and an outlet pipe (7). The lower end of the reducing pipe (3) is connected to an oil casing installed in the formation. A heat exchange inner pipe (4) is fitted around the oil casing. The upper end of the heat exchange inner pipe (4) extends at least to the upper end of the reducing pipe (3). The outer periphery of the reducing pipe (3) and the inner periphery of the heat exchange inner pipe (4) form an annular cavity. The inlet pipe (1) and the outlet pipe (7) are both located at the upper end of the reducing pipe (3). The outlet pipe (7) is connected to the heat exchange inner pipe (4), and the inlet pipe (1) is connected to the annular cavity.

2. The well connection device for medium-deep geothermal wells according to claim 1, characterized in that, The upper end of the reducing pipe (3) is provided with a cover flange (2), the water inlet pipe (1) is connected to the upper end of the cover flange (2), and the heat exchange inner pipe (4) extends out of the cover flange (2) and is connected to the water outlet pipe (7).

3. The well connection device for medium-deep geothermal wells according to claim 2, characterized in that, The reducing pipe (3) is an eccentric reducing joint (031).

4. The well connection device for medium-deep geothermal wells according to claim 2, characterized in that, The reducing pipe (3) includes an eccentric reducing joint (031) and an extension pipe (032). The lower end of the eccentric reducing joint (031) is connected to the oil casing, and the upper end of the eccentric reducing joint (031) is connected to the extension pipe (032). The upper end of the extension pipe (032) is provided with the cover flange (2).

5. A well connection device for medium-deep geothermal wells according to claim 4, characterized in that, The heat exchange inner tube (4) is fixed to the cover plate flange (2) through a T-joint (5) and is connected to the water outlet pipe (7).

6. A well connection device for medium-deep geothermal wells according to claim 5, characterized in that, The cover flange (2) is provided with a groove, and a sealing ring (8) is embedded in the groove. The lower end face of the T-joint (5) abuts against the sealing ring (8).

7. A well connection device for medium-deep geothermal wells according to claim 6, characterized in that, The lower end of the outlet pipe (7) is provided with a crimp flange (6), and the outlet pipe (7) is connected to the T-type joint (5) through the crimp flange 6.

8. A well connection device for medium-deep geothermal wells according to claim 3 or 4, characterized in that, The eccentric reducing joint (031) is a tube with different inner diameters at its two ends, and the axis of one end opening is offset from the axis of the other end opening.

9. A well connection device for medium-deep geothermal wells according to claim 8, characterized in that, The upper ends of the inlet pipe (1) and the outlet pipe (7) are both arc-shaped pipes, and the lower ends of the inlet pipe (1) and the outlet pipe (7) are both vertical pipes.

10. A well connection device for medium-deep geothermal wells according to claim 6, characterized in that, The sealing ring (8) is a silicone sealing ring.

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