Indirect heat exchange type high-temperature product well system for underground coal gasification

Abstract

The utility model relates to the field of high-temperature product wells, in particular to an indirect heat exchange type high-temperature product well system for underground coal gasification, which comprises a backflow component, an output component connected onto the backflow component, a wellhead component connected onto the output component and a cooling component connected onto the wellhead component. The cooling assembly comprises a rear cooling cylinder connected to the wellhead assembly and a front cooling cylinder connected to the rear cooling cylinder. The servo motor drives the rotating lead screw to rotate, and the rotating lead screw drives the sliding block in clearance fit with the rotating lead screw to move along the rotating lead screw, so that the sliding tube plate connected with the sliding block can move synchronously, and a corrugated tube connected to the sliding tube plate can be deformed and stretched; the heat exchange area is adjusted, the entering synthesis gas is cooled through the plate tube assembly, the problem of shaft damage is solved, and meanwhile sewage generated by cooling of the synthesis gas is not increased.

Description

TECHNICAL FIELD

[0001] The utility model relates to high temperature product well field especially relates to an indirect heat exchange formula high temperature product well system for coal underground gasification. BACKGROUND

[0002] When the coal seam has an injection well, a product well and a horizontal passage connecting the two, the structure is called an underground coal gasification (ISC) unit or well pair. The ISC unit includes a combustion zone, a gasification zone and a pyrolysis zone. The combustion zone is near the oxidant injection point in the coal seam; the gasification zone surrounds the combustion zone in a radial pattern or is downstream of the combustion zone, where coal is gasified and partially oxidized to produce product gas; the pyrolysis zone is downstream of the gasification zone, where coal pyrolysis generally occurs. The high-temperature product gas flows downstream from the gasification zone and is ultimately transported to the surface from the product wellhead. At the same time as the coal is burned or gasified, the ISC combustion void in the coal seam grows larger. The product gas produced by underground coal gasification typically contains syngas and other components such as solid particles, water, coal tar, hydrocarbon vapor, and other trace components including H2S, NH4, COS, etc. The complexity of its composition depends on many factors: the oxidant used in underground coal gasification, the internal water in the coal seam or the water infiltrated into the coal seam from the surrounding strata, the coal quality, and the operating parameters of the underground coal gasification process, including temperature, pressure, etc.

[0003] However, the conventional product well of the underground gasification furnace is damaged by high temperature when the high-temperature syngas passes through the wellbore, causing the casing, tubing and cementing cement of the wellbore to be damaged under the action of thermal stress, thereby causing the entire product well to have a phenomenon of reduced working efficiency. UTILITY MODEL CONTENTS

[0004] In order to overcome the problem that the product well of the existing underground gasification furnace is inevitably damaged by high-temperature syngas during use, thereby affecting the normal use of the product well and causing a decrease in the safety of the product well.

[0005] The technical scheme of the utility model is: an indirect heat exchange formula high temperature product well system for coal underground gasification, comprising a reflux assembly, an output assembly connected to the reflux assembly, a wellhead assembly connected to the output assembly, and a cooling assembly connected to the wellhead assembly.

[0006] The temperature reducing assembly comprises a rear temperature reducing cylinder connected to the wellhead assembly, a front temperature reducing cylinder connected to the rear temperature reducing cylinder, a stretching assembly and a plate pipe assembly connected to inner walls of the rear temperature reducing cylinder and the front temperature reducing cylinder respectively, a first connecting head and a second connecting head connected to the rear temperature reducing cylinder, a fourth connecting head and a third connecting head connected to the front temperature reducing cylinder, a connecting pipe connected to the fourth connecting head, a product well screen pipe connected to the connecting pipe, and a fixed pipe plate connected to the product well screen pipe, wherein a plurality of through holes are formed in the fixed pipe plate.

[0007] As a preferred, the stretching assembly comprises a fixed sheet connected to the inner walls of the rear temperature reducing cylinder and the front temperature reducing cylinder, a servo motor connected to the fixed sheet, a rotating screw connected to an output shaft of the servo motor, and a sliding block intermittently matched with the rotating screw.

[0008] As a preferred, the plate pipe assembly comprises a sliding pipe plate connected to the sliding block, a plurality of corrugated pipes connected to the sliding pipe plate, and a plurality of guide plates connected to the corrugated pipes.

[0009] As a preferred, the wellhead assembly comprises a mounting pipe connected to the first connecting head, a tubing connected to the mounting pipe, a coiled tubing connected to the tubing, a return pipe connected to the coiled tubing, a connecting cover connected to the tubing, a flow divider connected to the coiled tubing, and a wellhead assembly connected to the flow divider.

[0010] As a preferred, the wellhead assembly comprises a fixed cover connected to the flow divider, a wellhead seat connected to the fixed cover, a casing connected to the wellhead seat, and a cement sheath connected to the casing.

[0011] As a preferred, the output assembly comprises a fifth connecting pipe connected to the flow divider, a delivery pump connected to the fifth connecting pipe, a fourth connecting pipe connected to the delivery pump, and a water storage pool connected to the fourth connecting pipe.

[0012] As a preferred, the return assembly comprises a third connecting pipe connected to the water storage pool, a plate heat exchanger connected to the third connecting pipe, a first connecting pipe connected to the plate heat exchanger, a lifting pump connected to the first connecting pipe, and a second connecting pipe connected to the lifting pump, wherein the second connecting pipe is connected to the flow divider.

[0013] The utility model discloses the beneficial effects of:

[0014] 1. The utility model discloses a servo motor drives rotating screw to rotate to drive the sliding block of the clearance cooperation with rotating screw to move along rotating screw through rotating rotating screw, thereby making the sliding tube plate connected with the sliding block can move synchronously, to make the bellows connected on the sliding tube plate can carry out deformation stretch, thereby realize the adjustment to the heat exchange area, and through the plate pipe subassembly to the cooling of entering synthetic gas, to solve the problem of wellbore damage, can also not increase the sewage produced by synthetic gas cooling simultaneously;

[0015] 2. The utility model discloses a plurality of bellows are set up, and the special wave crest and wave trough design of bellows makes the fluid flow due to the continuous mutation of pipe inside and outside section forms strong turbulent flow, even under the condition of very small flow rate, fluid can form strong disturbance in pipe inside and outside, greatly improves the heat transfer coefficient when heat exchange, and the bellows in the working process, on the one hand, the medium in pipe inside and outside is always in the highly turbulent state, makes the solid particle in medium difficult to deposit scale formation, on the other hand, under the influence of medium temperature difference, bellows will produce slight axial expansion and contraction deformation, the curvature of pipe inside and outside will change frequently, because the linear expansion coefficient of scale layer and bellows is very different, so the pull-off force between scale and bellows is big, even if there is scale deposition, will break and automatically fall off, thereby making bellows always keep the long -term, efficient heat exchange performance. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The utility model discloses an indirect heat exchange type high temperature product well system's three -dimensional structure schematic diagram is shown.

[0017] Figure 2 The utility model discloses an indirect heat exchange type high temperature product well system's wellhead assembly first three -dimensional structure schematic diagram is shown.

[0018] Figure 3 The utility model discloses an indirect heat exchange type high temperature product well system's wellhead assembly second three -dimensional structure schematic diagram is shown.

[0019] Figure 4 The utility model discloses an indirect heat exchange type high temperature product well system's cooling assembly's three -dimensional structure schematic diagram is shown.

[0020] Explanation of reference signs: 1, reflux assembly; 2, output assembly; 3, wellhead assembly; 4, temperature reduction assembly; 101, plate heat exchanger; 102, first connecting pipe; 103, lifting pump; 104, second connecting pipe; 105, third connecting pipe; 201, water storage tank; 202, fourth connecting pipe; 203, delivery pump; 204, fifth connecting pipe; 301, fixed cover; 302, wellhead seat; 303, flow divider; 304, oil pipe; 305, connecting cover; 306, continuous pipe; 307, mounting pipe; 308, reflux pipe; 309, sleeve pipe; 310, cementing cement sheath; 401, rear temperature reduction cylinder; 402, fixed sheet; 403, servo motor; 404, rotating screw rod; 405, sliding block; 406, sliding pipe plate; 407, corrugated pipe; 408, flow guide plate; 409, first connecting head; 410, second connecting head; 411, front temperature reduction cylinder; 412, third connecting head; 413, fourth connecting head; 414, connecting pipe; 415, product well screen pipe; 416, fixed pipe plate. DETAILED DESCRIPTION

[0021] The utility model will be further explained in connection with the drawings and examples.

[0022] An indirect heat exchange type high-temperature product well system for underground coal gasification, according to Figures 1-4 as shown, comprising a reflux assembly 1, an output assembly 2 connected to the reflux assembly 1, a wellhead assembly 3 connected to the output assembly 2, and a temperature reduction assembly 4 connected to the wellhead assembly 3;

[0023] The temperature reduction assembly 4 comprises a rear temperature reduction cylinder 401 connected to the wellhead assembly 3, a front temperature reduction cylinder 411 connected to the rear temperature reduction cylinder 401, a stretching assembly and a plate pipe assembly respectively connected to the inner walls of the rear temperature reduction cylinder 401 and the front temperature reduction cylinder 411, a first connecting head 409 and a second connecting head 410 connected to the rear temperature reduction cylinder 401, a fourth connecting head 413 and a third connecting head 412 connected to the front temperature reduction cylinder 411, a connecting pipe 414 connected to the fourth connecting head 413, a product well screen pipe 415 connected to the connecting pipe 414, and a fixed pipe plate 416 connected to the product well screen pipe 415, wherein a plurality of through holes are formed in the fixed pipe plate 416.

[0024] According to Figure 4 as shown, the stretching assembly comprises a fixed sheet 402 connected to the inner walls of the rear temperature reduction cylinder 401 and the front temperature reduction cylinder 411, a servo motor 403 connected to the fixed sheet 402, a rotating screw rod 404 connected to the output shaft of the servo motor 403, and a sliding block 405 intermittently matched to the rotating screw rod 404.

[0025] It should be noted that the servo motor 403 drives the rotating screw 404 to rotate, and the rotating screw 404 drives the sliding block 405, which is in clearance with it, to move along the rotating screw 404. This allows the sliding tube plate 406 connected to the sliding block 405 to move synchronously, so that the bellows 407 connected to the sliding tube plate 406 can be deformed and stretched, thereby realizing the adjustment of the heat exchange area.

[0026] according to Figure 4 As shown, the tube plate assembly includes a sliding tube plate 406 connected to a sliding block 405, a plurality of bellows 407 connected to the sliding tube plate 406, and a plurality of guide plates 408 connected to the bellows 407.

[0027] It should be noted that by setting up several bellows 407, and through the special crest and trough design of the bellows 407, strong turbulence is formed due to the continuous abrupt changes in the cross-section inside and outside the pipe during fluid flow. Even at very low flow velocities, the fluid can generate strong disturbances inside and outside the pipe, which greatly improves the heat transfer coefficient during heat exchange. At the same time, during the operation of the bellows 407, on the one hand, the medium inside and outside the pipe is always in a highly turbulent state, making it difficult for solid particles in the medium to deposit and form scale; on the other hand, affected by the temperature difference of the medium, the bellows 407 will produce a small amount of axial expansion and contraction deformation, and the curvature inside and outside the pipe will change frequently. Since the linear expansion coefficients of the scale layer and the bellows 407 are very different, a large pull-off force will be generated between the scale and the bellows 407. Even if scale is deposited, it will break and fall off automatically, thus enabling the bellows 407 to maintain a long-lasting and efficient heat exchange performance.

[0028] according to Figure 2 and Figure 3 As shown, the wellhead assembly 3 includes an installation pipe 307 connected to the first connector 409, an oil pipe 304 connected to the installation pipe 307, a continuous pipe 306 connected to the oil pipe 304, a return pipe 308 connected to the continuous pipe 306, a connecting cover 305 connected to the oil pipe 304, a diverter 303 connected to the continuous pipe 306, and a derrick assembly connected to the diverter 303.

[0029] according to Figure 2 and Figure 3 As shown, the derrick assembly includes a fixed cover 301 connected to the distributor 303, a wellhead seat 302 connected to the fixed cover 301, a casing 309 connected to the wellhead seat 302, and a cementing sheath 310 connected to the casing 309.

[0030] according to Figure 1 and Figure 3As shown, the output component 2 includes a fifth pipe 204 connected to the splitter 303, a delivery pump 203 connected to the fifth pipe 204, a fourth pipe 202 connected to the delivery pump 203, and a water storage tank 201 connected to the fourth pipe 202.

[0031] It should be noted that the water inside the reservoir 201 is transported to the inside of the diverter 303 through the fourth pipe 202 and the fifth pipe 204 by the transfer pump 203.

[0032] according to Figure 1 As shown, the reflux assembly 1 includes a third pipe 105 connected to the water storage tank 201, a plate heat exchanger 101 connected to the third pipe 105, a first pipe 102 connected to the plate heat exchanger 101, a booster pump 103 connected to the first pipe 102, and a second pipe 104 connected to the booster pump 103. The second pipe 104 is connected to the distributor 303.

[0033] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An indirect heat exchange type high-temperature product well system for underground coal gasification, characterized in that: It includes a reflux assembly (1), an output assembly (2) connected to the reflux assembly (1), a wellhead assembly (3) connected to the output assembly (2), and a cooling assembly (4) connected to the wellhead assembly (3); The cooling assembly (4) includes a rear cooling cylinder (401) connected to the wellhead assembly (3), a front cooling cylinder (411) connected to the rear cooling cylinder (401), a tensioning assembly and a plate-tube assembly respectively connected to the inner walls of the rear cooling cylinder (401) and the front cooling cylinder (411), a first connector (409) and a second connector (410) connected to the rear cooling cylinder (401), a fourth connector (413) and a third connector (412) connected to the front cooling cylinder (411), a connecting pipe (414) connected to the fourth connector (413), a product well screen pipe (415) connected to the connecting pipe (414), and a fixed tube plate (416) connected to the product well screen pipe (415). The fixed tube plate (416) has several through holes.

2. The indirect heat exchange type high-temperature product well system for underground coal gasification according to claim 1, characterized in that: The stretching assembly includes a fixed plate (402) connected to the inner walls of the rear cooling cylinder (401) and the front cooling cylinder (411), a servo motor (403) connected to the fixed plate (402), a rotating lead screw (404) connected to the output shaft of the servo motor (403), and a sliding block (405) intermittently engaged with the rotating lead screw (404).

3. The indirect heat exchange type high-temperature product well system for underground coal gasification according to claim 2, characterized in that: The plate and tube assembly includes a sliding tube plate (406) connected to a sliding block (405), a plurality of bellows (407) connected to the sliding tube plate (406), and a plurality of guide plates (408) connected to the bellows (407).

4. The indirect heat exchange type high-temperature product well system for underground coal gasification according to claim 1, characterized in that: The wellhead assembly (3) includes an installation pipe (307) connected to a first connector (409), an oil pipe (304) connected to the installation pipe (307), a coiled pipe (306) connected to the oil pipe (304), a return pipe (308) connected to the coiled pipe (306), a connecting cover (305) connected to the oil pipe (304), a splitter (303) connected to the coiled pipe (306), and a derrick assembly connected to the splitter (303).

5. The indirect heat exchange type high-temperature product well system for underground coal gasification according to claim 4, characterized in that: The derrick assembly includes a fixed cover (301) connected to the splitter (303), a wellhead seat (302) connected to the fixed cover (301), a casing (309) connected to the wellhead seat (302), and a cementing sheath (310) connected to the casing (309).

6. The indirect heat exchange type high-temperature product well system for underground coal gasification according to claim 4, characterized in that: The output component (2) includes a fifth pipe (204) connected to the splitter (303), a delivery pump (203) connected to the fifth pipe (204), a fourth pipe (202) connected to the delivery pump (203), and a water storage tank (201) connected to the fourth pipe (202).

7. The indirect heat exchange type high-temperature product well system for underground coal gasification according to claim 6, characterized in that: The reflux assembly (1) includes a third pipe (105) connected to the water storage tank (201), a plate heat exchanger (101) connected to the third pipe (105), a first pipe (102) connected to the plate heat exchanger (101), a booster pump (103) connected to the first pipe (102), and a second pipe (104) connected to the booster pump (103), the second pipe (104) being connected to the distributor (303).

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