Super-long gravity assisted heat pipe suitable for medium-high temperature geothermal energy

Abstract

The super-long gravity heat pipe comprises an outer pipe and an inner pipe, the lower end of the outer pipe is of a closed structure, the lower end of the inner pipe is communicated with the outer pipe, an elastic pressing plate is arranged on the periphery of the lower end of the inner pipe, and the edge of the elastic pressing plate is in contact with the inner wall of the outer pipe. A plurality of layers of annular flow guide plates are arranged between the lower end of the inner pipe and the bottom of the outer pipe, and the flow guide plates are of a structure inclining downwards from the middle of the outer pipe to the edge of the outer pipe. The elastic pressing plate is arranged at the bottom of the inner pipe, so that low-temperature liquid is tightly attached to the inner wall of the outer pipe to enter the evaporation section on the lower portion, and the contact heat exchange area between the low-temperature liquid and middle gas is reduced; and the descending low-temperature liquid is dispersed to the periphery of the outer pipe, so that the heat exchange probability of the high-temperature gas and the low-temperature liquid is further reduced, and the utilization efficiency of geothermal energy is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to geothermal energy system field especially suitable for super long gravity heat pipe for medium and high temperature geothermal energy. BACKGROUND

[0002] Geothermal energy is natural heat energy extracted from the crust, which comes from the lava inside the earth and exists in the form of heat. As a kind of natural heat energy stored in the earth and a highly competitive clean renewable energy, geothermal energy has the advantages of large reserves, wide distribution, green low carbon, strong applicability and good stability, and is mainly applied in the fields of power generation and heating. The extraction of geothermal energy currently mainly relies on super long gravity heat pipe to realize, first, the super long gravity heat pipe is inserted into the ground three kilometers or more in depth, then the low-temperature liquid (low-boiling-point liquid such as isopentane, ammonia, etc.) is free-falling into the bottom of the pipe under the action of gravity in the pipe, and after being heated by high-temperature soil or lava, it becomes gas and returns to the ground, and finally the hot gas is sent to the power plant for power generation or directly connected to the heating system. The conventional super long gravity heat pipe is of hollow structure, and the low-temperature liquid and the high-temperature gas are severely mixed in the pipe, so that the high-temperature gas to the power generation side or the heating side transfers part of the heat to the low-temperature liquid, resulting in the reduction of power generation efficiency or heating efficiency and poor system economy. SUMMARY

[0003] In order to overcome the above-mentioned deficiencies of the existing super long gravity heat pipe, the technical problem to be solved by the utility model is to provide a super long gravity heat pipe suitable for medium and high temperature geothermal energy extraction, which can realize the separation of low-temperature liquid and high-temperature gas.

[0004] The technical scheme adopted by the utility model to solve its technical problem is:

[0005] The super long gravity heat pipe suitable for medium and high temperature geothermal energy extraction comprises an outer pipe and an inner pipe, the lower end of the outer pipe is a closed structure, the lower end of the inner pipe is connected with the outer pipe at a distance from the bottom of the outer pipe, the periphery of the lower end of the inner pipe is provided with an elastic pressing plate, the edge of the elastic pressing plate is in contact with the inner wall of the outer pipe, the low-temperature liquid in the outer pipe can make the elastic pressing plate elastically deform downward under the action of gravity and pass through the gap between the elastic pressing plate and the inner wall of the outer pipe, and a plurality of annular flow guide plates are arranged between the lower end of the inner pipe and the bottom of the outer pipe, and the flow guide plates are inclined downward from the middle of the outer pipe to the edge of the outer pipe.

[0006] Further, the inner pipe is a vacuum pipe with a double-layer structure.

[0007] Further, the bottom plate of the bottom of the outer pipe is a corrugated plate, and the pipe in the distance from the lower end of the outer pipe to the bottom plate is a corrugated pipe.

[0008] Further, the elastic pressing plate is an annular structure composed of a plurality of sector plates, and is inclined downward from the inner pipe to the outer pipe.

[0009] Further, the bottom of the outer tube is provided with a plurality of support bars in the vertical direction, the support bars are located in the projection range of the inner tube at the bottom of the outer tube, and the annular inner wall of the guide plate is fixed on the support bars.

[0010] Further, the guide plate gradually increases in width from bottom to top.

[0011] The utility model discloses the beneficial effect is: through setting up the elastic pressing plate in the inner tube bottom, makes low temperature liquid to stick to the outer tube inner wall and enters the evaporation section below, reduces its contact heat exchange area with the middle gas, in addition through setting up the annular guide plate in the middle of evaporation section, makes the high temperature gas that rises and gathers to the outer tube middle part and enters the inner tube, and the low temperature liquid that drops is dispersed to the outer tube periphery, further reduced the heat exchange probability of high temperature gas and low temperature liquid, thereby improved the utilization efficiency of geothermal energy. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is the structure schematic diagram of the utility model;

[0013] Figure 2 It is Figure 1 A-A section view in the middle;

[0014] Figure 3 It is Figure 1 B-B section view in the middle.

[0015] Marked as in the drawing, 1-outer tube, 2-inner tube, 3-elastic pressing plate, 4-guide plate, 5-corrugated plate, 6-corrugated pipe, 7-support bar. DETAILED DESCRIPTION

[0016] The utility model is further described below in connection with the drawings.

[0017] It should be noted that if the utility model has involved directional indication language, such as up, down, left, right, front, back, direction, orientation language, it is for the description of the relative position connection between components, not the absolute position of the related components, the position relationship between components, only for explaining the relative position relationship between components, movement condition etc. in a certain posture, if the specific posture changes, then the directionality indication also changes accordingly. If the utility model has involved the language of quantity, such as "multiple", "multiple", "several" etc., it specifically refers to two and two or more.

[0018] Such as Figure 1 , Figure 2As shown, the utility model provides a kind of super-long gravity heat pipe suitable for medium-high temperature geothermal energy, including outer tube 1 and inner tube 2, the lower end of outer tube 1 is closed structure, inner tube 2 lower end distance outer tube 1 bottom a distance, and with outer tube 1 intercommunication, the periphery of inner tube 2 lower end is equipped with elastic pressing plate 3, the edge of elastic pressing plate 3 is in contact with the inner wall of outer tube 1, and the low-temperature liquid in outer tube 1 can be elastically deformed downwards under the action of gravity, and pass through the gap between elastic pressing plate 3 and the inner wall of outer tube 1;Multiple annular flow guide plates 4 are equipped between inner tube 2 lower end and outer tube 1 bottom, and flow guide plate 4 is inclined downwards from the middle of outer tube 1 to the edge of outer tube 1 structure.

[0019] Wherein, the space between inner tube 2 lower end and outer tube 1 bottom is evaporation section, for low-temperature liquid and outer tube 1 bottom contact gasification, the length of evaporation section is determined according to the longitudinal temperature of geothermal field measured in actual well drilling process.Elastic pressing plate 3 can adopt thinner aluminum alloy plate or spring steel plate, its inner end is fixed in inner tube 2 lower end, and outer end is elastically abutted on the inner wall of outer tube 1, when a certain low-temperature liquid is accumulated above elastic pressing plate 3, the outer end of elastic pressing plate 3 will bend downwards, so that low-temperature liquid passes, and elastic pressing plate 3 resets when liquid is less, therefore, elastic pressing plate 3 can make low-temperature liquid flow down along the edge of outer tube 1, and can control the flow of low-temperature liquid to a certain extent.The number of layers and interval of flow guide plate 4 are reasonably designed according to the length of evaporation section, preferably evenly distributed between inner tube 2 lower end and outer tube 1 bottom.

[0020] The working process of the utility model is: first, the whole gravity heat pipe is inserted into the ground three kilometers and above, because the closer to the center of the earth, the higher the temperature of the earth, so the gravity heat pipe presents the state of low temperature in the upper part and high temperature in the lower part;Then, low-temperature liquid is sent into outer tube 1 on the ground, under the action of gravity, low-temperature liquid pushes away elastic pressing plate 3 and then falls down, in the process of falling down, because the ground temperature is higher and higher, the temperature of outer tube 1 is also higher and higher, the temperature of low-temperature liquid gradually rises, when low-temperature liquid is close to the bottom of outer tube 1, low-temperature liquid is heated into high-temperature steam, finally high-temperature steam naturally rises, in the process of rising, steam is guided by flow guide plate 4, and is collected to the middle of outer tube 1 and enters inner tube 2, which can reduce the energy waste caused by steam entering outer tube 1 from the edge of elastic pressing plate 3, and flow guide plate 4 can also block the low-temperature liquid falling from above, reduce the heat transfer between high-temperature steam and low-temperature liquid, and provide heat energy utilization rate.

[0021] Because the whole gravity heat pipe is long, high-temperature steam in inner tube 2 will heat transfer with low-temperature liquid in outer tube 1 in the process of rising, so as to reduce the temperature of steam, therefore, in order to reduce heat transfer, the inner tube 2 can be preferably double-layer structure vacuum tube.

[0022] In order to increase the contact area between the bottom of the super-long gravity heat pipe and the high-temperature lava, and enable the outer pipe 1 to fully absorb the heat of the high-temperature lava, the bottom plate of the outer pipe 1 can be set as a corrugated plate 5, and the pipe within a distance from the lower end of the outer pipe 1 to the bottom plate can be set as a corrugated pipe 6.

[0023] For the elastic pressing plate 3, in order to facilitate the downward bending deformation thereof, the elastic pressing plate 3 can be set as a ring-shaped structure composed of a plurality of sector-shaped plates, and is downwardly inclined from the inner pipe 2 to the outer pipe 1. In this way, the downward bending deformation of the elastic pressing plate 3 is more uniform, and the low-temperature liquid can be more dispersedly introduced into the lower evaporation section. In addition, the elastic pressing plate 3 can also be realized by using a common steel plate plus a torsion spring structure. The elastic pressing plate 3 is hinged to the lower end of the inner pipe 2, and a torsion spring is sleeved on the hinge shaft. Under the elastic force of the torsion spring, the outer end of the elastic pressing plate 3 abuts against the inner wall of the outer pipe 1. When the amount of liquid accumulated on the elastic pressing plate 3 is greater than the elastic force of the torsion spring, the elastic pressing plate 3 rotates downward, so that the liquid flows down from the edge of the elastic pressing plate 3.

[0024] For the structure of the flow guide plate 4, the preferred scheme of the utility model is that, as shown in Figure 3 the bottom of the outer pipe 1 is provided with a plurality of support bars 7 in the vertical direction, the support bars 7 are all located within the projection range of the inner pipe 2 at the bottom of the outer pipe 1, and the annular inner wall of the flow guide plate 4 is fixed on the support bars 7. All the support bars 7 are limited within the projection range of the inner pipe 2 at the bottom of the outer pipe 1, in order to make the inner diameter of the inner ring of the flow guide plate 4 less than the inner diameter of the inner pipe 2, so that it can be ensured that most of the steam guided by the flow guide plate 4 can enter the inner pipe 2. The support bars 7 can be preferably 4-6, and are uniformly welded on the bottom plate of the outer pipe 1, so as to ensure the stability of the support of the flow guide plate 4. In addition, since the closer the gravity heat pipe is to the bottom, the higher the temperature of the gravity heat pipe after absorbing the underground heat energy, the smaller the temperature difference between the liquid and the gas in the pipe, and the weaker the heat conduction phenomenon between the liquid and the gas, the flow guide plate 4 can be set to be narrower, and the farther it goes upwards, the greater the temperature difference between the liquid and the gas in the pipe. In order to weaken the heat conduction phenomenon, the flow guide plate 4 can be set to be wider.

Claims

1. An ultra-long gravity heat pipe suitable for medium- and high-temperature geothermal energy extraction, characterized in that: It includes an outer tube (1) and an inner tube (2). The lower end of the outer tube (1) is a closed structure. The lower end of the inner tube (2) is a distance away from the bottom of the outer tube (1) and is connected to the outer tube (1). An elastic pressure plate (3) is provided around the lower end of the inner tube (2). The edge of the elastic pressure plate (3) is in contact with the inner wall of the outer tube (1). The low temperature liquid in the outer tube (1) can cause the elastic pressure plate (3) to deform downward under the action of gravity and pass through the gap between the elastic pressure plate (3) and the inner wall of the outer tube (1). A multi-layer annular guide plate (4) is provided between the lower end of the inner tube (2) and the bottom of the outer tube (1). The guide plate (4) has a structure that slopes downward from the middle of the outer tube (1) to the edge of the outer tube (1).

2. The ultra-long gravity heat pipe suitable for medium- and high-temperature geothermal energy extraction as described in claim 1, characterized in that: The inner tube (2) is a vacuum tube with a double-layer structure.

3. The ultra-long gravity heat pipe suitable for medium- and high-temperature geothermal energy extraction as described in claim 1, characterized in that: The bottom plate of the outer tube (1) is a corrugated plate (5), and the pipe within a certain distance from the bottom plate at the lower end of the outer tube (1) is a corrugated pipe (6).

4. The ultra-long gravity heat pipe suitable for medium- and high-temperature geothermal energy extraction as described in claim 1, characterized in that: The elastic pressure plate (3) is a ring structure composed of multiple fan-shaped plates, and it is inclined downward from the inner tube (2) to the outer tube (1).

5. The ultra-long gravity heat pipe suitable for medium- and high-temperature geothermal energy extraction as described in claim 1, characterized in that: The bottom of the outer tube (1) is provided with multiple support bars (7) in the vertical direction. The support bars (7) are all located within the projection range of the inner tube (2) at the bottom of the outer tube (1). The annular inner wall of the guide plate (4) is fixed on the support bars (7).

6. The ultra-long gravity heat pipe suitable for medium- and high-temperature geothermal energy extraction as described in claim 1, characterized in that: The width of each layer of the guide plate (4) gradually increases from bottom to top.

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