Self-expansion type single-channel spiral flow deflector and underground coal gasification application method

Abstract

The invention discloses a self-expansion type single-channel spiral flow deflector which comprises a flow guide part which is of a continuous spiral sheet structure and can be compressed when pressure is applied to the outer side of the flow guide part; the outer side of the flow guide part is sleeved with a sleeving part, and the sleeving part can limit the compressed flow guide part; through mechanical constraint shaping, elastic recovery expansion of the flow deflectors within 15 seconds is achieved, and interference fit with the casing pipe under the attaching pressure larger than or equal to 3 MPa is formed; by means of the optimized design of shape memory alloy pre-compression, a mechanical constraint release activation mechanism, an interference fit fixing mode with a sleeve, a reserved center cavity with the diameter larger than or equal to 0.5 D, a compatible ignition device with the diameter smaller than or equal to 300 mm, the spiral angle ranging from 25 degrees to 40 degrees and the screw pitch ranging from 0.6 D to 1.0 D, airflow is guided to form a 5-8 m / s rotating flow field, the gas-solid contact time is prolonged by 25%-35%, and the carbon conversion rate is increased by 10%-15%; the yield of synthesis gas (H + CO) is increased by 8-12%; and ash accumulation is inhibited by centrifugal force.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underground coal gasification channel airflow optimization, and in particular to a self-expanding single-channel spiral flow guide vane and an underground coal gasification application method. BACKGROUND

[0002] The existing underground coal gasification channel spiral flow guide technology mainly has the following limitations: Traditional welded spiral flow guide vanes: manual downhole or complex mechanical arm welding installation is required, the safety risk is high in the high-temperature and gas environment of the underground, and the welded welds are easy to be eroded and cracked by ash and slag, resulting in the falling of the flow guide vanes; Hot water activated self-expanding flow guide structure: depends on hot water expansion, needs to inject additional hot medium, and is easy to produce residual water, which causes abnormal water content of the coal seam during ignition and affects the gasification efficiency; Ordinary elastic flow guide structure: without pre-compression shaping design, the elastic recovery force is insufficient (<3 MPa), and a reliable interference fit cannot be formed in the coal seam channel, and the elastic flow guide structure is easy to loosen and fall off due to airflow impact or slight deformation of the coal seam. SUMMARY

[0003] Therefore, the technical problem to be solved by the present application is.

[0004] The above technical problem is solved by the following technical scheme: the present application provides a self-expanding single-channel spiral flow guide vane, which comprises a flow guide part, which is a continuous spiral sheet structure and can be compressed when pressure is applied to the outside of the flow guide part. A sleeve part is provided on the outside of the flow guide part, and the sleeve part can limit the compressed flow guide part.

[0005] In a preferred embodiment of the self-expanding single-channel spiral flow guide vane of the present application: the sleeve part comprises a plurality of sleeve pieces, and the plurality of sleeve pieces are connected by connecting pieces, and the sleeve pieces and the connecting pieces can form a circular pipe structure which can be sleeved on the outside of the flow guide part.

[0006] In a preferred embodiment of the self-expanding single-channel spiral flow guide vane of the present application: the sleeve piece and the connecting piece are both arc-shaped plate structures.

[0007] In a preferred embodiment of the self-expanding single-channel spiral flow guide vane of the present application: a clamping groove is formed on both sides of each sleeve piece, and the clamping groove axially penetrates both ends of the sleeve piece.

[0008] In a preferred embodiment of the self-expanding single-channel spiral flow guide vane of the present application: the clamping groove is wedge-shaped from the edge to the middle position of the sleeve piece, and the outside of the connecting piece is wedge-shaped to match the clamping groove.

[0009] In a preferred embodiment of the self-expanding single-channel helical guide vane, the guide portion is made of a multi-layer composite material.

[0010] In a preferred embodiment of the self-expanding single-channel helical guide vane, the center of the guide portion forms a cylindrical cavity when it is compressed in the sleeve portion.

[0011] In a preferred embodiment of the self-expanding single-channel helical guide vane, the outer diameter of the guide portion has a pre-compression amount of 8%-10%, and the guide portion can expand radially to D2=D+1-2mm after being released from the constraint.

[0012] A method for installing a self-expanding single-channel helical guide vane in an underground coal gasification installation, comprising the self-expanding single-channel helical guide vane described above, further comprising, a helical guide unit, an elastic driving unit, and an ignition avoidance unit; the ignition avoidance unit is a cavity with a diameter ≥0.5D (D is the diameter of the sleeve of the underground gasification channel) reserved at the center of the guide vane; The sleeve portion is fitted on the outside of the elastic driving unit, and the hydraulic system is used to press synchronously in the radial direction to compress the elastic driving unit to a preset amount, and the wedge-shaped block is locked in the pre-compressed state; After the guide vane is shaped, it is lowered to the target position underground, the ground winch pulls the recovery connecting piece, the elastic driving unit releases the elastic energy, and the guide vane self-expands and is fixed with the inner wall of the sleeve within 15 seconds; The ignition device reaches the ignition point through the ignition avoidance unit to complete the ignition, and the gasification agent forms a rotational flow field along the helical guide unit to achieve sufficient gas-solid reaction.

[0013] In a preferred embodiment of the self-expanding single-channel helical guide vane, the gasification agent is oxygen or water vapor, which forms a rotational flow field with a tangential velocity of 5-8m / s after being guided by the helical guide unit, and the gas-solid contact time is extended by 25%-35%.

[0014] The beneficial effects of the present application are that: the Ti-Ni-Hf20% hafnium modified high-temperature nickel-titanium shape memory alloy with 8%-10% pre-compression is used as the driving layer, and through mechanical constraint shaping, elastic recovery expansion within 15 seconds is realized, and interference fit with a sleeve is formed with a bonding pressure of ≥3MPa; the pre-compression of the shape memory alloy, the mechanical constraint release activation mechanism, and the interference fit fixing mode with the sleeve reserve a central cavity with a diameter of ≥0.5D, compatible with ignition devices with a diameter of ≤300mm, and the optimized design of a helix angle of 25°-40° and a pitch of 0.6-1.0D guides airflow to form a rotating flow field with a speed of 5-8m / s, prolongs the gas-solid contact time by 25%-35%, increases the carbon conversion rate by 10%-15%, and increases the synthesis gas (H2+CO) yield by 8%-12%; the centrifugal force suppresses the accumulation of ash, and solves the core pain points of uneven airflow in the channel and ash blockage. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present application, but not limit the present application. Among them: Figure 1 A front view of a self-expanding single-channel spiral guide vane is shown; Figure 2 A structural schematic diagram of a self-expanding single-channel spiral guide vane is shown; Figure 3 A structural schematic diagram of a guide part in a self-expanding single-channel spiral guide vane is shown; Figure 4 An installation schematic diagram of a guide vane is shown. DETAILED DESCRIPTION

[0016] In order to make those skilled in the art better understand the present application, the present application will be further described in detail below in combination with specific embodiments and drawings.

[0017] The terms used in the present application are those general terms currently widely used in the art in consideration of the functions about the present application, but these terms can be changed according to the intention of those skilled in the art, precedents, or new technologies in the art. In addition, specific terms can be selected by the applicant, and in this case, the detailed meaning thereof will be described in the detailed description of the present application. Therefore, the terms used in the specification should not be understood as mere names, but based on the meaning of the terms and the overall description of the present application.

[0018] REFERENCE Figures 1-3 The present embodiment provides a self-expanding single-channel spiral guide vane, which comprises a guide part 1, which is a continuous spiral sheet structure and can be compressed when pressure is applied to the outside of the guide part 1; The outer side of the flow guide part 1 is sleeved with a sleeve joint part 2, which can limit the compressed flow guide part 1; the outer side of the flow guide part is sleeved with a sleeve joint part, which is a detachable combined structure, used to limit and fix the flow guide part after compression, to avoid the invalidation of the pre-compression state; the sleeve joint part is coaxially arranged with the flow guide part, and after assembly, it can make the flow guide part maintain a preset compression amount, and does not damage the composite ceramic coating on the surface of the flow guide part; after the flow guide piece is lowered to the target position in the well, the elastic recovery force of the flow guide part can be released by unlocking the sleeve joint part, so that it rapidly expands radially and forms a reliable interference fit with the inner wall of the casing.

[0019] Further, the sleeve joint part 2 includes a plurality of sleeve pieces 21, which are connected by a connecting piece 22, and the sleeve piece 21 and the connecting piece 22 can form a circular pipe structure which can be sleeved on the outer side of the flow guide part 1; the tubular structure formed by the sleeve piece 21 and the connecting piece 22 limits the compressed flow guide part 1.

[0020] Further, the sleeve piece 21 and the connecting piece 22 are both arc-shaped plate structures; the sleeve piece 21 is a three-piece structure and is evenly distributed circumferentially along the flow guide part 1, ensuring that the compression force is applied radially synchronously, and the arc of the sleeve piece 21 and the connecting piece 22 makes the inner wall more conformal to the outer diameter of the flow guide part 1.

[0021] Further, the plurality of sleeve pieces 21 are provided with clamping grooves 23 on both sides, which axially penetrate the two ends of the sleeve piece 21; the clamping grooves 23 are used to accommodate the connecting piece 22, realizing the stable assembly of the sleeve piece 21 and the connecting piece 22.

[0022] Further, the clamping grooves 23 are wedge-shaped, becoming wider from the edge to the middle of the sleeve piece 21, and the outer side of the connecting piece 22 is wedge-shaped to match the clamping grooves 23; through the wedge self-locking feature, the connecting piece 22 is automatically wedged under the elastic recovery pressure of the flow guide part 1, maintaining the pre-compression state of the flow guide part 1.

[0023] Further, the flow guide part 1 is made of multi-layer composite material; it is composed of three layers of "flow guide substrate + elastic piece driving layer + surface functional layer"; the flow guide substrate is made of 310S stainless steel with a temperature resistance of ≥1200℃ and a tensile strength of ≥515MPa, and is processed into a continuous spiral blade; the elastic piece driving layer is the core driving layer, which is composed of ceramic-based inorganic glue on the inner side of the substrate, and uses Ti-Ni-Hf20% hafnium modified high-temperature nickel-titanium shape memory alloy with an elastic recovery force of 5MPa and a temperature resistance of ≥800℃, which is attached to the substrate after pre-compression of 8%-10%; the surface functional layer is the outer side airflow contact surface sprayed with Al2O3-ZrO2 composite ceramic coating with a thickness of 0.3-0.5mm and a hardness of >80HRC.

[0024] Further, the center of the flow guide part 1 forms a cylindrical cavity when compressed in the sleeve part 2; the center of the flow guide part 1 forms a cylindrical cavity when compressed in the sleeve part 2, and the cylindrical cavity constitutes an ignition avoidance unit with a diameter ≥0.5D, D being the diameter of the underground gasification passage sleeve, and compatible with a laser / electric arc ignition device with a diameter ≤30mm.

[0025] Further, the outer diameter of the flow guide part 1 has a 8%-10% pre-compression amount, and the maximum pressure applied during pre-compression is ≤30MPa; the elastic recovery force of the elastic driving layer of the flow guide part 1 reaches 5MPa, the temperature resistance is ≥800℃, and the flow guide part 1 can be radially expanded to D2=D+1-2mm after being released from the constraint, and the flow guide part 1 forms a fitting pressure ≥3MPa and a friction force >15kN with the inner wall of the sleeve after being released.

[0026] During use, the flow guide part 1 is placed horizontally on a special support, and after checking that the ceramic coating is not damaged, the three-sleeve part 21 is combined outside the flow guide part 1, and the sleeve part 21 is coaxially centered with the flow guide part 1; the hydraulic drive system is started, and the oil cylinder applies pressure radially and synchronously, slowly compressing the three-sleeve part 21, and the laser range finder feeds back the outer diameter of the flow guide part 1 in real time; when the outer diameter is compressed from the original to the corresponding 8%-10% pre-compression amount, and the compression force displayed by the pressure sensor is ≤30MPa and does not exceed the 20% elastic limit of Ti-Ni-Hf, the pressure is stopped; after the sleeve part 21 is compressed in place, the three connecting parts 22 are manually pushed into the inter-limb groove gap along the axial direction, and the wedge surface self-locking characteristic is used to resist the rebound pressure of the elastic sheet, forming a "wedge-shaped block self-locking" locking, at this time the elastic sheet stores the rebound energy, even if the hydraulic pressure is removed, it still remains in the compressed state; In one embodiment of the present application, referring to Figures 1-4 A self-expanding single-channel spiral flow guide piece underground coal gasification installation application method, comprising the self-expanding single-channel spiral flow guide piece, further comprising, The spiral flow guide unit is the flow guide part 1, the elastic driving unit is a prefabricated Ti-Ni-Hf 20% hafnium modified high-temperature nickel-titanium shape memory alloy layer, which can be radially expanded to D2=D+1-2mm after being released from the constraint, with a fitting pressure ≥3MPa and a friction force >15kN, relying on the super-elastic recovery force of the Ti-Ni-Hf 20% shape memory alloy after pre-compression of 8%-10% to meet the requirements, ensuring no risk of falling off during gasification; The spiral flow guide unit is a continuous spiral structure processed from a 310S stainless steel base material, with a spiral track error <0.5mm and no local protrusions, avoiding airflow turbulence; The ignition avoiding unit is compatible with laser ignition device or electric arc ignition device with diameter ≤300mm, ensuring the smooth passage of the ignition device to the ignition point. The elastic driving unit is compressed to a preset amount by the hydraulic system along the radial synchronous pressure, and the embedded connecting part locks the pre-compression state. The elastic driving unit is fitted on the outside of the flow guide part 1 through the sleeve part 2, and the hydraulic system is used to synchronously pressurize along the radial direction to make the flow guide part 1 reach a pre-compression amount of 8%-10%, and the embedded connecting part 22 wedge block locks the pre-compression state. The outer diameter of the flow guide part 1 is fed back in real time by the laser range finder during the pressurization process, ensuring accurate control of the compression amount. The hydraulic equipment is removed, and a pull rope is connected to the tail of the connecting part 22, which is connected to the ground winch. The shaped flow guide piece is lowered to the target position in the well, and the connecting part 22 is recovered by pulling the pull rope by the ground winch. The elastic driving unit releases the elastic energy, and self-expands and fits with the inner wall of the sleeve within 15 seconds. The connecting part 22 is recovered to release the constraint, and the Ti-Ni-Hf layer of the elastic piece releases the stored elastic energy to generate outward radial thrust, and the self-expanding interference fits on the sleeve. The ignition device reaches the ignition point through the ignition avoiding unit to complete the ignition, and the gasification agent forms a rotating flow field along the spiral flow guide unit to realize sufficient gas-solid reaction.

[0027] Further, the gasification agent is oxygen or water vapor, which forms a rotating flow field with a tangential velocity of 5-8m / s after being guided by the spiral flow guide unit, and the gas-solid contact time is extended by 25%-35%. When the amount of ash accumulation in the well is >5mm, the centrifugal force generated by the rotating flow field will carry away the ash, realizing self-cleaning of the channel.

[0028] Finally, it should be pointed out that the above detailed description of the method and device is only an embodiment, and those skilled in the art can modify the embodiment in different ways without departing from the scope of the present application.

Claims

1. A self-expanding single-passage helical vane, characterized by: include, The guide section (1) has a continuous spiral plate structure and can be compressed when pressure is applied to the outside of the guide section (1); The outer side of the guide section (1) is provided with a sleeve (2), which can limit the compressed guide section (1).

2. The self-expanding single-channel helical vane of claim 1, wherein: The sleeve part (2) includes multiple sets of sleeve parts (21), which are connected to each other by a connector (22). The sleeve parts (21) and the connector (22) can form a cylindrical structure, which can be sleeved on the outside of the guide part (1).

3. The self-expanding single-channel helical vane of claim 2, wherein: Both the sleeve (21) and the connector (22) are plate-shaped structures with curvature.

4. The self-expanding single-channel spiral guide vane according to claim 3, characterized in that: The multiple sets of sleeves (21) are provided with slots (23) on both sides, and the slots (23) axially penetrate both ends of the sleeves (21).

5. The self-expanding single-channel spiral guide vane according to claim 4, characterized in that: The slot (23) is wedge-shaped, which widens from the edge to the middle of the sleeve (21), and the outer side of the connector (22) is wedge-shaped to match the slot (23).

6. The self-expanding single-channel spiral guide vane according to claim 5, characterized in that: The flow guide (1) is made of multi-layer composite material.

7. The self-expanding single-channel spiral guide vane according to claim 6, characterized in that: When the flow guide (1) is compressed in the sleeve (2), a cylindrical cavity is formed at its center.

8. The self-expanding single-channel spiral guide vane according to claim 7, characterized in that: The outer diameter of the guide part (1) has a pre-compression amount of 8%-10%, and the guide part (1) can be radially expanded to D2=D+1-2mm after the constraint is released.

9. A method for installing and applying a self-expanding single-channel spiral guide vane in underground coal gasification, characterized in that, Including the self-expanding single-channel spiral guide vane as described in any one of claims 1-8, it further includes, The spiral guide unit, the elastic drive unit, and the ignition avoidance unit; the ignition avoidance unit is a cavity with a diameter ≥ 0.5D (D is the diameter of the underground gasification channel sleeve) reserved in the center of the guide plate; The sleeve (2) is fitted onto the outside of the elastic drive unit, and the hydraulic system is used to apply pressure synchronously in the radial direction to compress the elastic drive unit to a preset amount, and the wedge block is embedded to lock the pre-compression state. The shaped guide plate is lowered to the target position in the well. The connecting piece (22) is retrieved by pulling the rope with the surface winch. The elastic drive unit releases the rebound energy and expands within 15 seconds and is fixed with an interference fit to the inner wall of the casing. The ignition device reaches the ignition point through the ignition avoidance unit to complete the ignition, and the gasifying agent forms a rotating flow field along the spiral guide unit to achieve a complete gas-solid reaction.

10. The method for applying self-expanding single-channel spiral guide vanes in underground coal gasification according to claim 9, characterized in that: The gasifying agent is oxygen or water vapor, which forms a rotating flow field with a tangential velocity of 5-8 m / s after being guided by the spiral flow guiding unit, thus extending the gas-solid contact time by 25%-35%.

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