An improved method for heat exchange in methanol synthesis process

Abstract

The present invention discloses an improved method for heat exchange in a methanol synthesis process, comprising the following steps: S1. The fresh gas from the fresh section of the compressor enters the inside of the protective bed after being preheated in the shell side of the shell-and-tube heat exchanger, forming the fresh gas of the protective bed; S2. The recycle gas from the recycle section of the compressor enters the inside of the protective bed after being preheated in the shell side of the shell-and-tube heat exchanger, and after being mixed with the fresh gas from the protective bed, they are respectively introduced into the interiors of three reactors. By utilizing the characteristics of the shell-and-tube heat exchanger, the present invention integrates the inlets and outlets of heat exchangers No. 1, 2, and 3. After integration, the inlets and outlets of heat exchangers No. 1, 2, and 3 can be combined into one shell-and-tube heat exchanger; by utilizing the characteristics of the shell-and-tube heat exchanger, the heat recovery method of the heat exchange process in the methanol synthesis process is improved, the heat recovery efficiency is increased, while solving the problems of equipment and floor area, the process is simple, easy to operate, safe, and stable.

Description

Technical Field

[0001] The present invention belongs to the technical field of methanol synthesis, and particularly relates to an improved method for heat exchange in methanol synthesis process. Background Technique

[0002] At present, large-scale industrial methanol synthesis processes basically adopt gas-phase synthesis processes, and large-scale methanol reactors and catalysts are both developing rapidly. The dominant large-scale methanol synthesis patent technologies in the world today include DAVY, Lurgi, Topsoe, etc. Except for the differences in synthesis towers, their heat recovery methods are different.

[0003] In existing equipment, three inlet and outlet heat exchangers are mainly used for heat exchange treatment in the methanol synthesis process. The three inlet and outlet heat exchangers themselves have a large number of equipment, occupy a large area, and the process operation is also relatively troublesome. When the prepared methanol is discharged, it is inevitable that external components will impact on the methanol discharge pipe, and the impact is likely to cause damage to the methanol discharge pipe, thus affecting the methanol discharge.

[0004] Therefore, it is necessary to invent an improved method for heat exchange in methanol synthesis process to solve the above problems. Summary of the Invention

[0005] In view of the above problems, the present invention provides an improved method for heat exchange in methanol synthesis process to solve the problems raised in the above background technique.

[0006] To achieve the above object, the present invention provides the following technical solution: An improved method for heat exchange in methanol synthesis process, comprising the following steps:

[0007] S1. The fresh gas from the fresh section of the compressor enters the inside of the protection bed after being preheated through the shell side of the shell-and-tube heat exchanger, forming the fresh gas of the protection bed;

[0008] S2. The recycle gas from the recycle section of the compressor enters the inside of the three reactors after being preheated through the shell side of the shell-and-tube heat exchanger and mixed with the fresh gas from the protection bed;

[0009] S3. The high-temperature synthesis gas formed after the reaction enters the inside of the tube side of the shell-and-tube heat exchanger, and the gas heat exchange between the tube side and the shell side of the shell-and-tube heat exchanger is utilized. Methanol is cooled and separated at the tube side outlet of the shell-and-tube heat exchanger, and the separated methanol is discharged through the discharge pipe;

[0010] S4. A protection device is installed on the surface of the discharge pipe to improve the safety of the discharge pipe.

[0011] Furthermore, the protection device includes a sleeve, which is sleeved around the surface of the discharge pipe. A plurality of strip grooves are arranged on the surface of the sleeve at equal intervals in a circular shape. A limiting rod is installed at the center of the strip groove, and both ends of the limiting rod are fixedly connected to both ends of the strip groove. A first limiting ring is sleeved on the surface of the discharge pipe. A plurality of connecting plates are fixedly connected to the outer circumferential surface of the first limiting ring at equal intervals in a circular shape, and the limiting rod penetrates through the outer ends of the connecting plates.

[0012] Furthermore, brackets are provided through both ends of the strip groove. A through groove corresponding to the limiting rod is provided at the center of the bracket, and the bracket is slidably matched with the limiting rod by means of the through groove. The two brackets are respectively located on both sides of the first limiting ring. A buffer device is provided at the inner end of the bracket, and the inner end of the buffer device is correspondingly clamped to the outer circumferential surface of the sliding ring. The sliding ring is slidably sleeved on the surface of the discharge pipe, and the inner circumferential surface of the sliding ring is attached to the outer circumferential surface of the discharge pipe.

[0013] Furthermore, a threaded rod is provided through the center of the outer end of the bracket. A convex rod is fixedly connected to the outer end of the connecting plate, and the convex rod penetrates through the center of the threaded rod. Rotating sleeves are spirally sleeved at both ends of the threaded rod, and the two rotating sleeves are respectively located outside the two brackets. A ring groove is provided on the outer circumferential surface of the rotating sleeve. A rubber sleeve is provided on the outer circumference of the sleeve. Second limiting rings are provided on the inner circumferential surfaces at both ends of the rubber sleeve. The inner circumference of the second limiting ring is correspondingly matched with a plurality of ring grooves.

[0014] Furthermore, the second limiting ring is made of elastic rubber material, and the inner side edge of the second limiting ring is closely attached to the inner side of the ring groove. The outer circumferential surface of the second limiting ring is integrated with the rubber sleeve, and the rubber sleeve is rotationally matched with the ring groove by means of the second limiting ring.

[0015] Furthermore, covers are correspondingly provided at both ends of the sleeve. A circular groove corresponding to the discharge pipe is provided at the center of the cover, and the end of the discharge pipe penetrates through the circular groove. The cover is correspondingly buckled at the opening of the end of the sleeve, and the outer circumferential edge of the cover does not contact the bracket.

[0016] Furthermore, the buffer device includes a fixed rod, which is fixed at the inner end of the bracket, and the center line of the fixed rod is parallel to the center line of the sleeve. Both ends of the fixed rod are sleeved with the outer ends of the first rotating frames, and the center of the fixed rod is sleeved with the outer end of the second rotating frame. The second rotating frame is located between the two first rotating frames, and the first rotating frame and the second rotating frame are connected by a torsion spring, and the torsion spring is sleeved on the surface of the fixed rod.

[0017] Furthermore, the inner ends of the two first rotating frames are rotatably sleeved with a first rolling frame, the inner ends of the second rotating frames are rotatably sleeved with a second rolling frame, a placement groove is arranged on the outer circumferential surface of the slip ring, and both the first rolling frame and the second rolling frame are located inside the placement groove. The first rotating frame is in rolling cooperation with the placement groove by means of the first rolling frame, and the second rotating frame is in rolling cooperation with the placement groove by means of the second rolling frame.

[0018] Furthermore, the first limiting ring is made of rubber material, and the inner circumferential surface of the first limiting ring does not contact the outer circumferential surface of the discharge pipe.

[0019] The technical effects and advantages of the present invention:

[0020] 1. By utilizing the characteristics of the coil-tube heat exchanger, the present invention integrates the No. 1, No. 2, and No. 3 inlet and outlet heat exchangers. After integration, the No. 1, No. 2, and No. 3 inlet and outlet heat exchangers can be combined into one coil-tube heat exchanger; by utilizing the characteristics of the coil-tube heat exchanger, the heat recovery method of the heat exchange process in the methanol synthesis process is improved, the heat recovery efficiency is increased, while solving the problems of equipment and land occupation, the process is simple, easy to operate, safe, and stable.

[0021] 2. When the inner ends of the brackets approach the slip ring, the first rotating frame and the second rotating frame rotate under the pressure of the brackets at this time. Both the first rotating frame and the second rotating frame rotate around the fixed rod as the center, that is, the first rotating frame rolls inside the placement groove of the slip ring by means of the first rolling frame, and the second rotating frame rolls inside the placement groove of the slip ring by means of the second rolling frame. During the rotation of the first rotating frame and the second rotating frame, the relative angle between the two becomes larger and larger. At this time, the inner ends of the first rotating frame and the second rotating frame start to twist the torsion spring, and the torsional force of the torsion spring further absorbs the pressure of the bracket. By using the torsional force of the torsion spring to absorb the impact force of the rubber sleeve on the outer end of the bracket, the first rolling frame and the second rolling frame can disperse the impact force of the bracket during the rolling process inside the placement groove, avoiding the impact force of the bracket directly acting on the surface of the discharge pipe, thereby improving the protection effect of the discharge pipe.

[0022] 3. When the impact force of the component on the rubber sleeve causes the rubber sleeve to rotate inside the annular groove of the plurality of rotating sleeves by means of the second limiting ring, the second limiting ring drives the rotating sleeve to rotate on the surface of the threaded rod during the rotation process. The spiral effect of the rotating sleeve and the threaded rod causes the rotating sleeve to move on the surface of the threaded rod. Since the internal thread directions of the two rotating sleeves are opposite, the two rotating sleeves gradually approach or move away during the rotation on the surface of the threaded rod. When an external component impacts on the outer circumferential surface of the rubber sleeve, the elastic force of the rubber sleeve itself can prevent the component from impacting on the sleeve. The sleeve can provide comprehensive protection for the discharge pipe, further preventing the component from contacting the outer circumferential surface of the discharge pipe, thereby avoiding collision damage on the surface of the discharge pipe caused by contact and improving the protection of the discharge pipe itself.

[0023] Other features and advantages of the present invention will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present invention. The objectives and other advantages of the present invention may be realized and attained by the structure particularly pointed out in the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 shows a heat exchange flow chart of a methanol synthesis process in the prior art;

[0026] Figure 2 shows an improved heat exchange flow chart of the methanol synthesis process according to an embodiment of the present invention;

[0027] Figure 3 shows an overall structural diagram of a protection device on the surface of a discharge pipe according to an embodiment of the present invention;

[0028] Figure 4 shows a schematic internal structure diagram of the protection device according to an embodiment of the present invention;

[0029] Figure 5 shows a schematic overall structure diagram of a buffer device according to an embodiment of the present invention;

[0030] In the figure: 1, discharge pipe; 2, sleeve; 3, strip groove; 4, limiting rod; 5, first limiting ring; 6, connecting plate; 7, bracket; 8, through groove; 9, sliding ring; 10, threaded rod; 11, rotating sleeve; 12, annular groove; 13, rubber sleeve; 14, second limiting ring; 15, cover plate; 16, circular groove; 17, fixing rod; 18, first rotating frame; 19, second rotating frame; 20, torsion spring; 21, first rolling frame; 22, second rolling frame; 23, placement groove. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0032] In Figure 1In the prior art, the heat exchange process of the methanol synthesis process is as follows:

[0033] The fresh gas from the fresh section of the compressor is preheated through the shell side of the No. 1 inlet and outlet heat exchanger and then enters the protective bed. The recycle gas from the recycle section of the compressor is preheated through the shell side of the No. 2 and No. 3 inlet and outlet heat exchangers, and then mixed with the fresh gas from the protective bed and enters the three reactors for reaction. The temperature of the syngas after the reaction is relatively high. The high-temperature syngas enters the tube sides of the No. 1, No. 2, and No. 3 inlet and outlet heat exchangers respectively to exchange heat with the gas in the shell side, achieving the effect of heat recovery. The syngas leaving the tube side is cooled through the discharge pipe 1 to separate the product methanol.

[0034] The present invention provides an improved method for heat exchange in the methanol synthesis process, as Figures 2-3 shown, including the following steps:

[0035] S1. The fresh gas from the fresh section of the compressor is preheated through the shell side of the coil-wound heat exchanger and then enters the interior of the protective bed to form the fresh gas of the protective bed;

[0036] S2. The recycle gas from the recycle section of the compressor is preheated through the shell side of the coil-wound heat exchanger, and then mixed with the fresh gas from the protective bed and respectively introduced into the interiors of the three reactors;

[0037] S3. The high-temperature syngas formed after the reaction is introduced into the tube side of the coil-wound heat exchanger, and the heat of the gas in the tube side and the shell side of the coil-wound heat exchanger is exchanged. The methanol is cooled and separated at the outlet of the tube side of the coil-wound heat exchanger, and the separated methanol is discharged through the discharge pipe 1;

[0038] S4. A protective device is installed on the surface of the discharge pipe 1 to improve the safety of the discharge pipe 1.

[0039] By utilizing the characteristics of the coil-wound heat exchanger, the No. 1, No. 2, and No. 3 inlet and outlet heat exchangers are integrated. After integration, the No. 1, No. 2, and No. 3 inlet and outlet heat exchangers can be combined into one coil-wound heat exchanger. By utilizing the characteristics of the coil-wound heat exchanger to improve the heat recovery method of the heat exchange process of the methanol synthesis process, the heat recovery efficiency is improved. While solving the problems of equipment and floor space, the process is simple, easy to operate, safe, and stable.

[0040] In Figure 4Among them, the protection device includes a sleeve 2, the sleeve 2 is sleeved on the surface of the discharge pipe 1, a plurality of strip grooves 3 are arranged on the surface of the sleeve 2 at equal intervals in a circumferential manner, a limiting rod 4 is installed at the center of the strip groove 3, and both ends of the limiting rod 4 are fixedly connected to both ends of the strip groove 3. A first limiting ring 5 is sleeved on the surface of the discharge pipe 1, and a plurality of connecting plates 6 are fixedly connected to the outer circumferential surface of the first limiting ring 5 at equal intervals in a circumferential manner, and the limiting rod 4 penetrates through the outer ends of the connecting plates 6. The first limiting ring 5 is made of rubber material, and the inner circumferential surface of the first limiting ring 5 does not contact the outer circumferential surface of the discharge pipe 1. The first limiting ring 5 is located at the center of the outer circumferential surface of the discharge pipe 1. A plurality of limiting rods 4 can limit the first limiting ring 5 to prevent the first limiting ring 5 from rotating on the surface of the discharge pipe 1. When the discharge pipe 1 fluctuates inside the sleeve 2, the first limiting ring 5 can be used to prevent the impact force of the discharge pipe 1 from shaking from colliding with the first limiting ring 5, improving the protection of the discharge pipe 1 inside the sleeve 2.

[0041] In Figure 4 and Figure 5 Among them, brackets 7 are provided through both ends of the strip groove 3. A through groove 8 corresponding to the limiting rod 4 is provided at the center of the bracket 7, and the bracket 7 is slidably matched with the limiting rod 4 through the through groove 8. The two brackets 7 are respectively located on both sides of the first limiting ring 5. A buffer device is provided at the inner end of the bracket 7, and the inner end of the buffer device is correspondingly clamped to the outer circumferential surface of the sliding ring 9. The sliding ring 9 is slidably sleeved on the surface of the discharge pipe 1, and the inner circumferential surface of the sliding ring 9 fits with the outer circumferential surface of the discharge pipe 1. The inner end of the bracket 7 uses the buffer device to move the sliding ring 9 to slide on the surface of the discharge pipe 1, and the rust on the surface of the discharge pipe 1 can be scraped off by the back-and-forth friction between the sliding ring 9 and the discharge pipe 1. A protective oil can be applied to the inner circumferential surface of the sliding ring 9. When the sliding ring 9 slides back and forth on the surface of the discharge pipe 1, the sliding ring 9 can apply the protective oil to the surface of the discharge pipe 1, increasing the protection effect of the discharge pipe 1.

[0042] In Figure 3 and Figure 4In it, a threaded rod 10 is penetrated and arranged at the center of the outer end of the bracket 7. A convex rod is fixedly connected to the outer end of the connecting plate 6. The convex rod penetrates through the center of the threaded rod 10. Threaded sleeves 11 are spirally sleeved at both ends of the threaded rod 10, and the two threaded sleeves 11 are respectively located outside the two brackets 7. An annular groove 12 is arranged on the outer circumferential surface of the threaded sleeve 11. A rubber sleeve 13 is arranged on the outer circumference of the sleeve 2. Second limiting rings 14 are arranged on the inner circumferences at both ends of the rubber sleeve 13. The inner circumference of the second limiting ring 14 is correspondingly matched with a plurality of annular grooves 12. The second limiting ring 14 is made of elastic rubber material, and the inner side edge of the circumference of the second limiting ring 14 is closely attached to the inner side of the annular groove 12. The outer circumferential surface of the second limiting ring 14 is integrally arranged with the rubber sleeve 13, and the rubber sleeve 13 is rotationally matched with the annular groove 12 by means of the second limiting ring 14. When the impact force of a component on the rubber sleeve 13 causes the rubber sleeve 13 to rotate inside the annular grooves 12 of the plurality of threaded sleeves 11 by means of the second limiting ring 14, the second limiting ring 14 drives the threaded sleeve 11 to rotate on the surface of the threaded rod 10 during the rotation process. The spiral effect of the threaded sleeve 11 and the threaded rod 10 further causes the threaded sleeve 11 to move on the surface of the threaded rod 10. Since the internal thread directions of the two threaded sleeves 11 are opposite, the two threaded sleeves 11 gradually approach or move away from each other during the rotation on the surface of the threaded rod 10. When an external component impacts on the outer circumferential surface of the rubber sleeve 13, at this time, the elastic force of the rubber sleeve 13 itself can prevent the component from impacting on the sleeve 2. The sleeve 2 can provide comprehensive protection for the discharge pipe 1, further preventing the component from contacting the outer circumferential surface of the discharge pipe 1, thereby avoiding the occurrence of collision damage on the surface of the discharge pipe 1 due to contact and improving the protection performance of the discharge pipe 1 itself.

[0043] In Figure 3 and Figure 4 In it, cover plates 15 are correspondingly arranged at both ends of the sleeve 2. A circular groove 16 corresponding to the discharge pipe 1 is arranged at the center of the cover plate 15, and the end of the discharge pipe 1 penetrates through the circular groove 16. The cover plate 15 is correspondingly buckled at the opening at the end of the sleeve 2, and the outer circumferential edge of the cover plate 15 does not contact the bracket 7. The cover plate 15 is sleeved on the discharge pipe 1 by means of the circular groove 16. By means of the cover plate 15, the center line of the discharge pipe 1 coincides with the center line of the sleeve 2, so that the distance between the outer circumferential surface of the discharge pipe 1 and the inner circumferential surface of the sleeve 2 is equal, avoiding the situation that the discharge pipe 1 and the sleeve 2 are offset.

[0044] In Figure 4 and Figure 5Among them, the buffer device includes a fixed rod 17, the fixed rod 17 is fixed to the inner end of the bracket 7, and the center line of the fixed rod 17 is parallel to the center line of the sleeve 2. Both ends of the fixed rod 17 are sleeved with the outer ends of the first rotating frame 18, and the outer end of the second rotating frame 19 is sleeved at the center of the fixed rod 17. The second rotating frame 19 is located between the two first rotating frames 18, and the first rotating frame 18 and the second rotating frame 19 are connected by a torsion spring 20. The torsion spring 20 is sleeved on the surface of the fixed rod 17. The inner ends of the two first rotating frames 18 are rotatably sleeved with a first rolling frame 21, and the inner end of the second rotating frame 19 is rotatably sleeved with a second rolling frame 22. A placement groove 23 is provided on the outer circumferential surface of the slip ring 9, and both the first rolling frame 21 and the second rolling frame 22 are located inside the placement groove 23. The first rotating frame 18 is in rolling cooperation with the placement groove 23 by means of the first rolling frame 21, and the second rotating frame 19 is in rolling cooperation with the placement groove 23 by means of the second rolling frame 22. When the inner end of the bracket 7 approaches the slip ring 9, at this time, the first rotating frame 18 and the second rotating frame 19 rotate under the pressure of the bracket 7. Both the first rotating frame 18 and the second rotating frame 19 rotate around the fixed rod 17 as the center, that is, the first rotating frame 18 rolls inside the placement groove 23 of the slip ring 9 by means of the first rolling frame 21, and the second rotating frame 19 rolls inside the placement groove 23 of the slip ring 9 by means of the second rolling frame 22. During the rotation of the first rotating frame 18 and the second rotating frame 19, the relative angle between the two becomes larger and larger. At this time, the inner ends of the first rotating frame 18 and the second rotating frame 19 start to twist the torsion spring 20. The torsional force of the torsion spring 20 further absorbs the pressure of the bracket 7, and uses the torsional force of the torsion spring 20 to absorb the impact force of the rubber sleeve 13 on the outer end of the bracket 7. During the rolling process of the first rolling frame 21 and the second rolling frame 22 inside the placement groove 23, the impact force of the bracket 7 can be dispersed, avoiding the impact force of the bracket 7 directly acting on the surface of the discharge pipe 1, thereby improving the protection effect of the discharge pipe 1.

[0045] Working principle of the present invention:

[0046] Refer to the attached drawings of the specification Figures 3-5 When an external component impacts on the outer circumferential surface of the rubber sleeve 13, the elastic force of the rubber sleeve 13 itself can prevent the component from impacting on the sleeve 2 at this time. The sleeve 2 can provide comprehensive protection for the discharge pipe 1, further preventing the component from contacting the outer circumferential surface of the discharge pipe 1, thereby avoiding collision damage on the surface of the discharge pipe 1 caused by contact and improving the protection performance of the discharge pipe 1 itself.

[0047] After the component impacts the rubber sleeve 13, the rubber sleeve 13 itself can absorb a part of the impact force of the component. The rubber sleeve 13 deforms under the impact force of the component, and the impacted part gradually approaches the outer side of the sleeve 2. At this time, the deformed rubber sleeve 13 uses the relative second limiting ring 14 to start pressing on the outer end of the corresponding part of the bracket 7. Under the action of the pressure, the bracket 7 moves on the surface of the limiting rod 4 by using the through groove 8. The threaded rod 10 itself can limit the outer end of the bracket 7, and the limiting rod 4 itself can limit the bracket 7, avoiding the situation of shaking during the movement of the bracket 7 and ensuring the stability of the bracket 7 during the movement. When the bracket 7 moves, the bracket 7 drives the threaded rod 10 to move on the surface of the convex rod, and the cooperation between the bracket 7 and the convex rod improves the stability of the threaded rod 10 during the movement.

[0048] When the inner end of the bracket 7 approaches the sliding ring 9, at this time, the first rotating frame 18 and the second rotating frame 19 rotate under the pressure of the bracket 7. Both the first rotating frame 18 and the second rotating frame 19 rotate with the fixed rod 17 as the center, that is, the first rotating frame 18 rolls inside the placement groove 23 of the sliding ring 9 by using the first rolling frame 21, and the second rotating frame 19 rolls inside the placement groove 23 of the sliding ring 9 by using the second rolling frame 22. During the rotation of the first rotating frame 18 and the second rotating frame 19, the relative angle between the two becomes larger and larger. At this time, the inner ends of the first rotating frame 18 and the second rotating frame 19 start to twist the torsion spring 20. The torsion force of the torsion spring 20 further absorbs the pressure of the bracket 7, uses the torsion force of the torsion spring 20 to absorb the impact force of the rubber sleeve 13 on the outer end of the bracket 7, and the first rolling frame 21 and the second rolling frame 22 can disperse the impact force of the bracket 7 during the rolling inside the placement groove 23, avoiding the impact force of the bracket 7 directly acting on the surface of the discharge pipe 1, thereby improving the protection effect of the discharge pipe 1.

[0049] The impact force of the component on the rubber sleeve 13 causes the rubber sleeve 13 to rotate inside the annular groove 12 of the plurality of rotating sleeves 11 by using the second limiting ring 14. During the rotation, the second limiting ring 14 drives the rotating sleeve 11 to rotate on the surface of the threaded rod 10. The spiral effect between the rotating sleeve 11 and the threaded rod 10 further causes the rotating sleeve 11 to move on the surface of the threaded rod 10. Since the internal thread directions of the two rotating sleeves 11 are opposite, the two rotating sleeves 11 gradually approach or move away from each other during the rotation on the surface of the threaded rod 10.

[0050] When the second limiting ring 14 drives the rotating sleeve 11 to rotate on the surface of the threaded rod 10, due to the limitation of the convex rod on the threaded rod 10, at this time, the two rotating sleeves 11 gradually approach or move away during the rotation process. The rotational cooperation between the rotating sleeve 11 and the threaded rod 10 drives the outer end of the bracket 7 to slide on the surface of the threaded rod 10. The inner end of the bracket 7 uses the buffer device to drive the sliding ring 9 to slide on the surface of the discharge pipe 1, and the rust on the surface of the discharge pipe 1 can be scraped off by the back-and-forth friction between the sliding ring 9 and the discharge pipe 1. A protective oil can be applied to the inner side surface of the circumference of the sliding ring 9. When the sliding ring 9 slides back and forth on the surface of the discharge pipe 1, the sliding ring 9 can apply the protective oil to the surface of the discharge pipe 1, increasing the protection effect of the discharge pipe 1.

[0051] When the two brackets 7 approach or move away from each other, the outer end of the top of the bracket 7 slides on the surface of the threaded rod 10, the center of the bracket 7 slides on the surface of the limiting rod 4 by using the through groove 8, and the inner end of the bracket 7 drives the sliding ring 9 to move back and forth on the surface of the discharge pipe 1 by using the buffer device, which facilitates the rubber sleeve 13 and the second limiting ring 14 to rotate along with the impact direction of the component. While using the rotation of the rubber sleeve 13 to offset the impact force of the component, it also avoids the impact force of the component acting on the discharge pipe 1.

[0052] Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some 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 invention.

Claims

1. An improved method for heat exchange in methanol synthesis process, characterized in that: It includes the following steps: S1. The fresh gas from the fresh section of the compressor enters the inside of the protective bed after being preheated in the shell side of the coil heat exchanger, forming the fresh gas of the protective bed; S2. The recycle gas from the recycle section of the compressor enters the inside of the three reactors after being preheated in the shell side of the coil heat exchanger and mixed with the fresh gas from the protective bed; S3. The high-temperature synthesis gas formed after the reaction enters the inside of the tube side of the coil heat exchanger. By using the heat exchange between the gas in the tube side and the shell side of the coil heat exchanger, methanol is cooled and separated at the outlet of the tube side of the coil heat exchanger, and the separated methanol is discharged through the discharge pipe (1); S4. A protective device is installed on the surface of the discharge pipe (1) to improve the safety of the discharge pipe (1); The protective device includes a sleeve (2), the sleeve (2) is sleeved on the surface of the discharge pipe (1), a plurality of strip grooves (3) are arranged on the surface of the sleeve (2) at equal intervals in the circumferential direction, a limiting rod (4) is installed at the center of the strip groove (3), and both ends of the limiting rod (4) are fixedly connected to both ends of the strip groove (3). A first limiting ring (5) is sleeved on the surface of the discharge pipe (1), and a plurality of connecting plates (6) are fixedly connected to the circumferential outer side surface of the first limiting ring (5) at equal intervals in the circumferential direction, and the limiting rod (4) penetrates through the outer ends of the connecting plates (6); Both ends of the strip groove (3) are provided with brackets (7) in a penetrating manner. A through groove (8) corresponding to the limiting rod (4) is arranged at the center of the bracket (7), and the bracket (7) is slidably matched with the limiting rod (4) by means of the through groove (8). The two brackets (7) are respectively on both sides of the first limiting ring (5). A buffer device is arranged at the inner end of the bracket (7), and the inner end of the buffer device is correspondingly clamped to the circumferential outer side surface of the sliding ring (9). The sliding ring (9) is slidably sleeved on the surface of the discharge pipe (1), and the circumferential inner side surface of the sliding ring (9) is attached to the circumferential outer side surface of the discharge pipe (1).

2. The method for heat exchange of the improved methanol synthesis process according to claim 1, characterized in that: A threaded rod (10) is arranged in a penetrating manner at the center of the outer end of the bracket (7). A convex rod is fixedly connected to the outer end of the connecting plate (6), and the convex rod penetrates through the center of the threaded rod (10). Rotating sleeves (11) are spirally sleeved at both ends of the threaded rod (10), and the two rotating sleeves (11) are respectively on the outer sides of the two brackets (7). An annular groove (12) is arranged on the circumferential outer side surface of the rotating sleeve (11). A rubber sleeve (13) is arranged on the circumferential outer side of the sleeve (2). Second limiting rings (14) are arranged on the circumferential inner side surfaces at both ends of the rubber sleeve (13), and the circumferential inner sides of the second limiting rings (14) are correspondingly matched with a plurality of annular grooves (12).

3. The method for heat exchange of the improved methanol synthesis process according to claim 2, characterized in that: The second limiting ring (14) is made of elastic rubber material, and the circumferential inner side edge of the second limiting ring (14) is closely attached to the inner side of the annular groove (12). The circumferential outer side surface of the second limiting ring (14) is integrally formed with the rubber sleeve (13), and the rubber sleeve (13) is rotationally matched with the annular groove (12) by means of the second limiting ring (14).

4. The improved method for heat exchange in methanol synthesis process according to claim 3, characterized in that: Cover plates (15) are correspondingly arranged at both ends of the sleeve (2). A circular groove (16) corresponding to and mating with the discharge pipe (1) is arranged at the center of the cover plate (15), and the end of the discharge pipe (1) penetrates through the circular groove (16). The cover plate (15) is correspondingly buckled at the end opening of the sleeve (2), and the outer circumferential side of the cover plate (15) does not contact the bracket (7).

5. The improved method for heat exchange in methanol synthesis process according to claim 4, characterized in that: The buffer device includes a fixed rod (17). The fixed rod (17) is fixed at the inner end of the bracket (7), and the central line of the fixed rod (17) is arranged parallel to the central line of the sleeve (2). Outer ends of both ends of the fixed rod (17) are sleeved with outer ends of the first rotating frames (18), and the outer end of the second rotating frame (19) is sleeved at the center of the fixed rod (17). The second rotating frame (19) is located between the two first rotating frames (18), and the first rotating frame (18) and the second rotating frame (19) are connected by a torsion spring (20). The torsion spring (20) is sleeved on the surface of the fixed rod (17).

6. The improved method for heat exchange in methanol synthesis process according to claim 5, characterized in that: Inner ends of the two first rotating frames (18) are rotatably sleeved with a first rolling frame (21). Inner ends of the second rotating frame (19) are rotatably sleeved with a second rolling frame (22). A placement groove (23) is arranged on the outer circumferential surface of the slip ring (9), and both the first rolling frame (21) and the second rolling frame (22) are located inside the placement groove (23). The first rotating frame (18) is in rolling cooperation with the placement groove (23) by means of the first rolling frame (21), and the second rotating frame (19) is in rolling cooperation with the placement groove (23) by means of the second rolling frame (22).

7. The improved method for heat exchange in methanol synthesis process according to claim 5, characterized in that: The first limiting ring (5) is made of rubber material, and the inner circumferential surface of the first limiting ring (5) does not contact the outer circumferential surface of the discharge pipe (1).

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