Heat recovery device for ammonia synthesis

Abstract

The invention discloses a heat recovery device for ammonia synthesis, which relates to the technical field of heat recovery, and comprises an ammonia synthesis tower provided with a side outlet for conveying gas out of the tower, and a cavity in which a blade plate for dividing the cavity into a plurality of chambers is fixedly arranged, wherein the heat exchange chamber is used for heat exchange of liquid, and the preheating chamber is used for preheating inlet air. According to the heat recovery device for ammonia synthesis, through rotation of the rear end cover, waste heat of tower outlet gas under the position alignment station of the fixing plate is completely used for generating steam, when the position is staggered, the tower outlet gas is subjected to first heat exchange through the cavity A and then subjected to heat exchange through the cavity B and the cavity C, and tower inlet gas is preheated through the cavity B and the cavity C; and finally, the waste heat of the gas out of the tower can be fully utilized to heat the gas in the tower, so that the gas out of the tower is fully cooled, the energy loss in the preheating link is reduced, and the effect of saving energy is further achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of heat recovery, and in particular to a heat recovery device for ammonia synthesis. Background Art

[0002] The heat recovery unit in the ammonia synthesis process is primarily used to recover the high-temperature heat released by the synthesis reaction, improving energy efficiency while reducing energy consumption and carbon emissions. Steam is generated by recovering the high-temperature waste heat from the synthesis gas, and multi-stage temperature recovery is implemented based on the characteristic that the temperature of the high-temperature waste heat decreases with heat exchange.

[0003] In conjunction with publication number CN110500904B, published on March 5, 2024, an integrated ammonia synthesis heat recovery device and ammonia synthesis heat recovery process are disclosed. The device comprises a first and second interconnected shell-and-tube heat exchanger, the first having a superheated steam outlet and a return air port; the second having a steam generation section and a preheating section; the tube side of the second heat exchanger is connected to the tube side of the first heat exchanger; the shell side of the second heat exchanger is disconnected from the shell side of the first heat exchanger; and a steam drum is disposed above the second heat exchanger, connected to the steam generation section, which is connected to the return air port of the first heat exchanger. In the ammonia synthesis heat recovery process using the above-described device, water in the second heat exchanger enters the steam drum to generate saturated steam, which then enters the first heat exchanger to generate superheated steam.

[0004] However, in the prior art including the above-mentioned patent, the temperature of the gas leaving the tower is between 360 and 390°C, and the saturated steam generated by the steam drum has a limited cooling effect on the gas leaving the tower. It is still necessary to set up a further cooling device to fully cool the gas leaving the tower before proceeding to the next step. Summary of the Invention

[0005] The object of the present invention is to provide a heat recovery device for ammonia synthesis to solve the above problems.

[0006] To achieve the above-mentioned object, the present invention provides the following technical solution: a heat recovery device for ammonia synthesis, comprising an ammonia synthesis tower, provided with a side outlet for conveying gas out of the tower, and comprising a cavity in which blades are fixedly provided for dividing the cavity into a plurality of chambers, including a heat exchange chamber for exchanging heat with liquid and a preheating chamber for preheating intake air;

[0007] The conveying assembly is arranged in a circular array in the cavity, including a plug-in plate, on which an S-bend pipe for conveying liquid or gas is fixed, and the gap between the plug-in plates is the gas outlet channel;

[0008] It also includes a front end cover fixedly arranged at the front end of the cavity and a rear end cover rotatably arranged at the rear end of the cavity, and a fixing plate is fixedly arranged in both the front end cover and the rear end cover;

[0009] The rear end cover is driven to rotate so that the fixed plates at both ends have two positions of alignment and staggering, and the preheating chamber is air-intaken at the staggered position of the fixed plates.

[0010] Preferably, the cavity further comprises an arc-shaped tube fixedly arranged at the rear end thereof and connected to the S-bend tube, wherein a partition for dividing the arc-shaped tube into an air inlet section and an air outlet section is fixedly arranged in the arc-shaped tube.

[0011] Preferably, the length direction of the S-bend pipe is consistent with the length direction of the cavity, and an inlet and an outlet are provided on the S-bend pipe, and the conveying direction of the inlet points to the axis of the cavity.

[0012] Preferably, a steam drum for generating steam is further included, and the steam drum is provided with a pressure-reducing pipe with an inner diameter increasing along the air intake direction.

[0013] Preferably, the cavity further comprises sealing components arranged at both ends, including a labyrinth seal and rubber sealing rings arranged on both sides of the labyrinth seal.

[0014] Preferably, rotating plates perpendicular to the inserting plates are rotatably provided on both sides of the inserting plates, and the multiple rotating plates are driven to deflect by the outgoing gas to form an inclined surface for guiding the diversion of the outgoing gas.

[0015] Preferably, it also includes an upper plate and a lower plate fixedly arranged on the inserting plate and used to limit the rotation direction of the rotating plate.

[0016] Preferably, the two rotating plates are symmetrically arranged, and after deflection, the rotating plates form an eight-shaped structure with the wide opening facing the axis of the cavity.

[0017] Preferably, the device further comprises an elastic member provided on the rotating plate and used for keeping the rotating plate at a fixed angle.

[0018] Preferably, it further comprises an ammonia synthesis water cooler for receiving the output gas from the cavity, on which a control valve is provided.

[0019] In the above technical solution, the present invention provides a heat recovery device for ammonia synthesis, which has the following beneficial effects: through the rotation of the rear end cover, the waste heat of the gas leaving the tower at the fixed plate in the aligned position is completely used to generate steam, and when the stationary position is staggered, the gas leaving the tower undergoes the first heat exchange in chamber A, and then undergoes heat exchange in chambers B and C, and the gas entering the tower is preheated by chambers B and C. Finally, the waste heat of the gas leaving the tower can be fully utilized to heat the gas entering the tower, thereby achieving sufficient cooling of the gas leaving the tower, and reducing the energy loss in the preheating link, further playing a role in saving energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0021] Figure 1 An overall three-dimensional schematic diagram provided for an embodiment of the present invention;

[0022] Figure 2 Schematic diagram of the end cover, sealing assembly and cavity structure provided by an embodiment of the present invention;

[0023] Figure 3 A schematic diagram of the structure inside the cavity provided by an embodiment of the present invention;

[0024] Figure 4 A schematic diagram of the cavity structure at another angle provided by an embodiment of the present invention;

[0025] Figure 5 A schematic diagram of the positions of the fixing plate, blade plate and cavity provided in an embodiment of the present invention;

[0026] Figure 6 A schematic diagram of the structure of the plug board and the rotating board provided in an embodiment of the present invention;

[0027] Figure 7 A schematic diagram of the default state structure of the transfer board provided in an embodiment of the present invention;

[0028] Figure 8 A schematic diagram of the structure of the rotating plate in a deflected state provided by an embodiment of the present invention;

[0029] Figure 9 A schematic diagram of the connection relationship between the chamber, ammonia synthesis tower and ammonia synthesis water cooler provided in an embodiment of the present invention;

[0030] Figure 10 This is a schematic diagram of the connection relationship between the cavity, ammonia synthesis tower and ammonia synthesis water cooler provided in an embodiment of the present invention.

[0031] Description of reference numerals:

[0032] 1. Front cover; 11. Inlet; 2. Cavity; 21. Water outlet pipe; 22. Connecting pipe; 23. Water inlet pipe; 231. Water inlet; 24. Arc-shaped pipe; 241. Partition; 242. First air inlet pipe; 243. Second air inlet pipe; 25. Blade; 26. Insert plate; 27. S-bend pipe; 271. Upper plate; 272. Rotating plate; 273. Lower plate; 274. Inlet; 275. Outlet; 276. Elastic part; 3. Rear cover; 31. Lead outlet; 4. Drive motor; 5. Pressure-reducing pipe; 6. Steam drum; 7. Workbench; 8. Fixed plate; 9. Sealing assembly; 91. Rubber sealing ring; 92. Labyrinth seal; 100. Ammonia synthesis tower; 101. Ammonia synthesis water cooler. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0034] like Figure 1-10 As shown, a heat recovery device for ammonia synthesis includes an ammonia synthesis tower 100 (such as Figure 9 and Figure 10 As shown), a side outlet for delivering gas out of the tower is provided on it, and the heat recovery device also includes a cavity 2 (as shown Figure 5 As shown), a blade 25 is fixedly provided therein for dividing the cavity 2 into a plurality of chambers, including a heat exchange chamber for exchanging heat with the liquid (such as Figure 5 A chamber shown in FIG) and a preheating chamber for preheating the intake air (such as Figure 5 Chambers B and C shown in );

[0035] The conveying assembly is arranged in a circular array in the cavity 2, including a plug plate 26 (such as Figure 3 As shown), an S-bend pipe 27 for conveying liquid or gas is fixedly provided thereon (as shown Figure 6 As shown), and the gap between the inserting plates 26 is the gas outlet channel;

[0036] The front end cover 1 is fixedly arranged at the front end of the cavity 2 and the rear end cover 3 is rotatably arranged at the rear end of the cavity 2 (such as Figure 1 As shown), and a fixing plate 8 is fixedly provided in both the front cover 1 and the rear cover 3 (as shown Figure 2 shown);

[0037] The rear end cover 3 is driven to rotate so that the fixed plates 8 at both ends have two positions (such as alignment and staggered) Figure 5 As shown), and the preheating chamber is air-intaken at the staggered position of the fixed plate 8.

[0038] Specifically, it also includes a workbench 7 for supporting the cavity 2 and a drive motor 4 for driving the rear end cover 3, which is assembled on the workbench 7. A small bevel gear is fixedly provided on the output shaft of the drive motor 4, and a large bevel gear is fixedly provided on the rear end cover 3 to mesh with the small bevel gear. The torque output by the drive motor 4 causes the small bevel gear to rotate and drives the large bevel gear to rotate, thereby rotating the rear end cover 3 and the fixed plate 8 therein. When the horizontal projections of the fixed plates 8 of the front end cover 1 and the rear end cover 3 are completely overlapped, it is an alignment position, and when the horizontal projections of the fixed plates 8 at both ends are completely staggered, it is a staggered position.

[0039] Furthermore, the number of blades 25 is three and the angle between the blades 25 is fixed at 120 degrees, and the cavity 2 is evenly divided into chamber A, chamber B and chamber C by the blades 25 (such as Figure 5 As shown), chamber A is a heat exchange chamber, and water flows through the S-bend pipe 27 in chamber A, while chambers B and C are preheating chambers, and tower gas flows through the S-bend pipes 27 in chambers B and C.

[0040] The cavity 2 further includes a water outlet pipe 21 and a water inlet pipe 23 (such as a pipe 23) fixedly disposed on the front and rear ends of the cavity 2. Figure 3 As shown), the water inlet pipe 23 is provided with a water inlet 231, and a steam drum 6 for generating steam and connected to the water outlet pipe 21. After water enters the water inlet pipe 23, it exchanges heat in the A chamber and then enters the water outlet pipe 21 uniformly, and finally enters the steam drum 6 from the water outlet pipe 21 to produce steam.

[0041] The front end of the cavity 2 includes three openings: A1, B1, and C1. The rear end of the cavity 2 corresponds to three openings: A2, B2, and C2. The angle of the fixing plate 8 is also 120 degrees. The fixing plate 8 in the front cover 1 is always located at the position B1. In the initial state, the fixing plate 8 of the rear cover 3 is located at the alignment position, that is, the position A2 (as shown in FIG. Figure 5 As shown in the middle figure, at this time, the gas out of the tower is taken in through the inlet 11 fixed on the front cover 1, the gas enters from A1, and is directly discharged from the outlet 31 fixed on the rear cover 3 through A2. The gas exchanges heat with the S-bend 27 in the A chamber. The gas in the cavity 2 is completely used to heat the S-bend 27 in the A chamber (i.e., the heat exchange chamber). Since the A chamber is heated, the temperature in the B and C chambers will slowly rise, which plays a role in heat preservation, and the waste heat of the gas out of the tower is completely used to generate steam.

[0042] When the fixing plate 8 of the rear end cover 3 is in the staggered position (such as Figure 5As shown in the figure below, the gas out of the tower still enters from A1, and then the gas in A1 enters A2 and undergoes the first heat exchange with chamber A. However, since the fixed plate 8 is located at the position of B2, only B2 is connected to the outlet 31 at this time, and A2 is connected to C2. After the gas in A2 reaches the rear end cover 3, it will return through C2 and enter C1. During this period, chamber C is heated. The gas is blocked by the fixed plate 8 at C1 and can only flow to B1. Finally, it returns again through B1 and reaches B2, and then heats chamber B and is discharged through the outlet 31. After exchanging heat with chamber A, the gas in cavity 2 enters chambers C and B in turn. The gas entering the tower is preheated by chambers C and B, and the waste heat of the gas out of the tower is used to heat the gas entering the tower. Compared with the conventional method of preheating the gas entering the tower by electric heating, the energy consumption required for preheating is reduced.

[0043] In the above technology, by rotating the rear end cover 3, the waste heat of the gas leaving the tower at the fixed plate 8 in the aligned position is completely used to generate steam. When the fixed plate 8 is in the staggered position, the gas leaving the tower undergoes the first heat exchange in chamber A, and then undergoes heat exchange in chambers B and C. The gas entering the tower is preheated by chambers B and C. Finally, the waste heat of the gas leaving the tower can be fully utilized to heat the gas entering the tower, thereby achieving sufficient cooling of the gas leaving the tower and reducing the energy loss in the preheating link, further playing a role in saving energy.

[0044] As an embodiment provided by the present invention, it also includes an arc tube 24 fixedly arranged at the rear end of the cavity 2 and connected to the S-bend 27, wherein a partition 241 (such as Figure 3 shown).

[0045] Specifically, such as Figure 3 The partition 241 divides the arc-shaped tube 24 into an outlet section and an inlet section corresponding to chambers B and C respectively. The inlet section is connected to the first inlet pipe 242, and the gas in the first inlet pipe 242 enters the S-bend 27 in chamber B through the inlet section. The front end of the chamber 2 is fixedly provided with a connecting pipe 22 for connecting the S-bends 27 in chambers B and C, while the other end of the S-bend 27 in chamber C is connected to the outlet section, and the outlet section is connected to the second inlet pipe 243. That is, the flow path of the gas in the first inlet pipe 242 is: inlet section of the arc-shaped tube 24 - S-bend 27 in chamber B - connecting pipe 22 - S-bend 27 in chamber C - outlet section of the arc-shaped tube 24 - second inlet pipe 243 (as shown in FIG. Figure 3 The gas finally enters the lower end of the ammonia synthesis tower 100 through the second air inlet pipe 243 (as shown by the dotted arrow in the middle). Figure 10 shown).

[0046] In the aligned position, the gas within chamber 2 is entirely used to heat S-bend 27 within chamber A (i.e., the heat exchange chamber). In the staggered position, the gas within chamber 2, after exchanging heat with chamber A, then enters chambers C and B in sequence. The gas temperature decreases as the heat is exchanged, resulting in a decreasing amount of heat exchange within chambers C and B. The gas transported within S-bend 27 enters chamber B before entering chamber C during intake, resulting in a gradual temperature increase. This allows the gas to fully utilize the waste heat of the gas exiting the tower to achieve a step-by-step temperature increase, ultimately entering the lower end of the ammonia synthesis tower 100 through second inlet pipe 243. This step-by-step temperature increase prevents excessive temperature increases on the gas entering the tower, thereby reducing the likelihood of deformation of the gas pipeline due to thermal stress. This allows for "gentle" thermal changes, extends the waste heat flow path, and maintains the footprint of the device.

[0047] As an embodiment provided by the present invention, the length direction of the S-bend 27 is consistent with the length direction of the cavity 2, and the S-bend 27 is provided with an inlet 274 and an outlet 275, and the conveying direction of the inlet 274 points to the axis of the cavity 2.

[0048] Specifically, since the gas out of the tower enters the front cover 1 through the inlet 11, the gas out of the tower flows horizontally between the two plug-in plates 26, and convection heat transfer occurs between the two adjacent plug-in plates 26. At this time, since the plug-in plates 26 are arranged in a circumferential array in the cavity 2 (such as Figure 3 As shown in FIG. 2 , the spacing between the insert plates 26 gradually increases from the axis to the circumference, and the convection cross-sectional area between two adjacent insert plates 26 gradually expands, that is, the heat transfer efficiency from the axis to the circumference of the cavity 2 gradually decreases. The insert plates 26 in chambers A and B are in opposite directions to the insert plates 26 in chamber C. The inlet 274 and outlet 275 of the S-bend 27 are both located on one side of the insert plate 26 (as shown in FIG. 2 ). Figure 6 As shown), the other side is movably connected to the central axis of the blade 25, so that the liquid inlet direction of the S-bend 27 is toward the axis, and the temperature is gradually increased through the horizontal bending of the S-bend 27. The temperature is higher at the part closer to the axis, and is finally quickly transmitted from the axis to the circumference through the outlet 275, thereby achieving a slow temperature increase of the incoming liquid or gas.

[0049] Among them, the inlet 274 in the A chamber is connected to the water inlet pipe 23, and the outlet 275 is connected to the water outlet pipe 21. The inlet 274 in the B chamber is connected to the air inlet section of the arc tube 24, and the outlet 275 is connected to the connecting pipe 22. The direction of the plug plate 26 in the C chamber is opposite to that of the A chamber and the B chamber. Therefore, the inlet 274 in the C chamber is connected to the connecting pipe 22, and the outlet 275 is connected to the air outlet section of the arc tube 24 (as shown in FIG. Figure 4As shown), the second air inlet pipe 243 is finally connected through the air outlet section, and the second air inlet pipe 243 leads to the bottom air inlet of the ammonia synthesis tower 100. The above connections are all connected by threaded connection or flange assembly, or other detachable assembly methods can be used.

[0050] As another embodiment provided by the present invention, it further includes a steam drum 6 for generating steam, and the steam drum 6 is provided with a pressure-reducing pipe 5 with an inner diameter increasing along the air intake direction.

[0051] Specifically, the pressure-reducing pipe 5 comprises at least two bucket-shaped structures connected in series, each of which is larger at the top and smaller at the bottom. This creates a stepped cross-section with an increasing inner diameter. The narrow end of the pressure-reducing pipe 5 communicates with the water outlet pipe 21, while the wide end communicates with the steam drum 6. After being heated in the S-bend 27, water enters the water outlet pipe 21. Because the cross-sectional area of the water outlet pipe 21 is smaller than that of the steam drum 6, a pressure differential exists when the liquid enters the steam drum 6 through the water outlet pipe 21, which can easily cause flash boiling. The pressure-reducing pipe 5 allows for gradual pressure relief, preventing instantaneous flash boiling.

[0052] As another embodiment provided by the present invention, it also includes a sealing assembly 9 arranged at both ends of the cavity 2, including a labyrinth seal 92 and rubber sealing rings 91 arranged on both sides of the labyrinth seal 92.

[0053] Specifically, the labyrinth seal 92 is fixedly arranged at both ends of the cavity 2 and extends axially into the front cover 1 and the rear cover 3 (such as Figure 2 (as shown), the front cover 1 and rear cover 3 are detachably assembled to the cavity 2, and an oil seal passage is formed between the outer wall of the labyrinth seal 92 and the inner walls of the two end covers. The two sides of this oil seal passage are restricted by rubber sealing rings 91. The sealing assembly 9 seals the cavity 2 and the connection between the front cover 1 and rear cover 3 to prevent gas leakage. When the rear cover 3 is driven to rotate, the oil seal passage reduces frictional resistance during the rotation.

[0054] As another embodiment provided by the present invention, rotating plates 272 perpendicular to the inserting plate 26 are rotatably provided on both sides of the inserting plate 26, and multiple rotating plates 272 are driven to deflect by the outgoing gas to form an inclined surface for guiding the outgoing gas diversion.

[0055] Specifically, it also includes an elastic member 276 (such as an elastic member 276) provided on the rotating plate 272 and used to keep the rotating plate 272 at a fixed angle. Figure 6In the default state, the rotating plate 272 is supported by the elastic force of the elastic member 276. At this time, the side surface of the rotating plate 272 is approximately horizontal with the width direction of the inserting plate 26. When the gas leaving the tower flows between the gaps between the inserting plates 26 along the length direction of the inserting plates 26, the gas pushes the rotating plate 272 to overcome the elastic force of the elastic member 276 and deflects. At this time, the rotating plate 272 is tilted, and the gas leaving the tower flows along the inclined surface formed by the tilt of the rotating plate 272. The inclined surface has a diversion effect on the gas leaving the tower, so that in addition to the mainstream horizontal flow from the front end to the rear end of the gas leaving the tower, multiple inclined tributaries are formed. The gas leaving the tower flows along the surface of the inserting plate 26 along the tributaries, extending the heat exchange contact time. The disturbance of the multiple rotating plates 272 can form turbulent flow, thereby improving the heat exchange efficiency of the gas leaving the tower.

[0056] When the gas outflow stops, the rotating plate 272 recovers due to the elastic release of the elastic member 276. The rapid release of the elastic member 276 creates a shaking effect, causing the surface of the rotating plate 272 to shake off impurities and the like intercepted during the heat exchange process. When cleaning the chamber 2, since the insert plate 26 is movably connected to the central axis of the blade 25, and the inlet 274 and outlet 275 of the S-bend 27 are both movably assembled, the insert plate 26 is detachably arranged in the chamber 2. Therefore, the insert plate 26 can be removed separately to clean the impurities shaken off, which is more convenient for maintenance.

[0057] As another embodiment provided by the present invention, it also includes an upper plate 271 and a lower plate 273 fixedly arranged on the inserting plate 26 and used to limit the rotation direction of the rotating plate 272.

[0058] Specifically, the positions of the upper plate 271 and the lower plate 273 are as follows: Figure 6 As shown, the upper ends of the rotating plates 272 abut against the opposite sides of the upper plate 271, while the lower ends of the rotating plates 272 abut against the adjacent sides of the lower plate 273. The elastic member 276 is provided on the lower plate 273 and pulls the lower end of the rotating plate 272 through its own elasticity.

[0059] When the gas flowing out of the tower flows along the length direction of the insert plate 26 between the gaps of the insert plate 26, the gas pushes the rotating plate 272 to deflect, and the deflection directions of two adjacent rotating plates 272 are opposite. Figure 7 Deflect to Figure 8 state, at this time, the rotating plate 272 forms a continuous "Z" path to form a diversion of the outgoing gas and extend the contact path between the outgoing gas and the surface of the inserting plate 26.

[0060] As another embodiment provided by the present invention, the two rotating plates 272 are symmetrically arranged, and the rotating plates 272 after deflection form an eight-shaped structure with the wide opening facing the axis of the cavity 2.

[0061] Specifically, when the fixed plate 8 is in the staggered position, the gas out of the tower goes back and forth in the three chambers ABC in the cavity 2. At this time, the axial center of the cavity 2 will be repeatedly subjected to heat exchange by the gas out of the tower, so the heat is concentrated at the axial center of the cavity 2. Two rotating plates 272 are grouped together. The rotating plates 272 in the group are pushed by the gas out of the tower to form an eight-shaped structure. The wide mouth of the eight-shaped structure faces the cavity 2. When the gas out of the tower flows along the axis, it will be separated by the inclined rotating plates 272 to form a small tributary. The tributary enters the eight-shaped structure and is guided by the eight-shaped structure to flow from the wide mouth to the narrow mouth. That is, the multiple tributaries of the gas out of the tower will diffuse radially, which plays a role in uniform temperature and reduces the concentrated heat at the axial center of the cavity 2. And the distance between adjacent groups is less than the width of the group, that is, when multiple groups are arranged linearly, the rotating plates 272 between the groups also enclose to form an eight-shaped structure, and the eight-shaped structure is opposite to the direction of the eight-shaped structure within the group (such as Figure 8 As shown), at this time, the eight-shaped opening between the combination groups is small, which has the effect of blocking and curbing the airflow flowing from the circumference to the axis.

[0062] As another embodiment provided by the present invention, it further includes an ammonia synthesis water cooler 101 for receiving the gas output from the cavity 2, and a control valve is provided on the water cooler.

[0063] Specifically, the output gas in the cavity 2 is cooled to 80°C after heat exchange, and then enters the ammonia synthesis water cooler 101. After cooling in the ammonia synthesis water cooler 101, the temperature drops to 40°C. After passing through the cold exchanger, the temperature drops to 20-23°C. It enters the ammonia synthesis cooler and is cooled to -8°C. It is then combined with the supplementary gas and enters the ammonia separator for ammonia separation. The gaseous ammonia produced by the ammonia synthesis cooler is sent to the refrigeration section. The separated gas enters the cold exchanger to recover the cold energy, and then enters the circulating gas compressor for the next cycle.

[0064] The control valve may be a solenoid valve or a flow control valve, which is used to control the flow rate of the ammonia synthesis water cooler 101 .

[0065] Working principle: By driving the motor 4 to output torque, the small bevel gear rotates and drives the large bevel gear to rotate, thereby rotating the rear end cover 3 and the fixed plate 8 inside it. When the horizontal projections of the front end cover 1 and the fixed plate 8 of the rear end cover 3 completely overlap, it is the alignment station.

[0066] Chamber A is the heat exchange chamber. Water flows through the S-bend 27 in chamber A. After entering the water inlet pipe 23, the water exchanges heat within chamber A before flowing into the water outlet pipe 21 and ultimately into the steam drum 6. Gas exiting the tower enters through the fixed inlet port 11 on the front end cover 1, enters through A1, and is directly discharged through A2 and the fixed outlet 31 on the rear end cover 3. The gas exchanges heat with the S-bend 27 in chamber A. The gas within chamber 2 is completely used to heat the S-bend 27 in chamber A (i.e., the heat exchange chamber).

[0067] The B and C chambers are preheating chambers, and the S-bend pipes 27 in the B and C chambers lead to the tower gas. Figure 5 As shown in the figure below, the gas out of the tower still enters from A1, and then the gas in A1 enters A2 and exchanges heat with chamber A for the first time. However, since the fixed plate 8 is located at the position of B2, only B2 is connected to the outlet 31 at this time, and A2 is connected to C2. After the gas in A2 reaches the rear end cover 3, it will return through C2 and enter C1. During this period, chamber C is heated. At C1, the gas is blocked by the fixed plate 8 and can only flow to B1. Finally, it returns again through B1 and reaches B2, and then heats chamber B and is discharged through the outlet 31. After exchanging heat with chamber A, the gas in cavity 2 enters chambers C and B in turn.

[0068] The flow path of the gas in the first air inlet pipe 242 is: the air inlet section of the arc-shaped pipe 24 - the S-shaped pipe 27 of the chamber B - the connecting pipe 22 - the S-shaped pipe 27 of the chamber C - the air outlet section of the arc-shaped pipe 24 - the second air inlet pipe 243 (as shown in FIG. Figure 3 The gas finally enters the lower end of the ammonia synthesis tower 100 through the second air inlet pipe 243 (as shown by the dotted arrow in the middle). Figure 10 shown).

[0069] When the gas out of the tower flows along the axis, it will be separated by the inclined rotating plate 272 to form a small branch. The branch enters the eight-shaped structure and is guided by the eight-shaped structure to flow from the wide mouth to the narrow mouth. That is, the multiple branches of the gas out of the tower will spread radially. The rotating plates 272 between the groups also enclose to form an eight-shaped structure, and the direction of the eight-shaped structure is opposite to that of the eight-shaped structure within the group (such as Figure 8 As shown), at this time, the eight-shaped opening between the combination groups is small, which has the effect of blocking and curbing the airflow flowing from the circumference to the axis.

[0070] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A heat recovery device for ammonia synthesis, comprising an ammonia synthesis tower (100) provided with a side outlet for conveying gas out of the tower, characterized in that: The heat recovery device comprises a cavity (2), in which a blade (25) is fixedly provided for dividing the cavity (2) into a plurality of chambers, including a heat exchange chamber for exchanging heat with a liquid and a preheating chamber for preheating an intake air; The conveying assembly is arranged in a circumferential array in the cavity (2), including a plug plate (26), on which an S-bend pipe (27) for conveying liquid or gas is fixedly arranged, and the gap between the plug plates (26) is a gas outlet channel; It also includes a front end cover (1) fixedly arranged at the front end of the cavity (2) and a rear end cover (3) rotatably arranged at the rear end of the cavity (2), and a fixing plate (8) is fixedly arranged in both the front end cover (1) and the rear end cover (3); The rear end cover (3) is driven to rotate so that the fixed plates (8) at both ends have two positions, one aligned and one staggered, and the preheating chamber is air-intaken at the staggered position of the fixed plates (8).

2. The heat recovery device for ammonia synthesis according to claim 1, characterized in that: It also includes an arc-shaped tube (24) fixedly arranged at the rear end of the cavity (2) and communicating with the S-bend tube (27), wherein a partition (241) is fixedly arranged in the arc-shaped tube (24) for dividing the arc-shaped tube (24) into an air inlet section and an air outlet section.

3. The heat recovery device for ammonia synthesis according to claim 1, characterized in that: The length direction of the S-bend pipe (27) is consistent with the length direction of the cavity (2), and an inlet (274) and an outlet (275) are provided on the S-bend pipe (27), and the conveying direction of the inlet (274) points to the axis of the cavity (2).

4. The heat recovery device for ammonia synthesis according to claim 1, characterized in that: It also includes a steam drum (6) for generating steam, and the steam drum (6) is provided with a pressure-reducing pipe (5) with an inner diameter increasing gradually along the air intake direction.

5. The heat recovery device for ammonia synthesis according to claim 1, characterized in that: It also includes sealing assemblies (9) arranged at both ends of the cavity (2), including a labyrinth seal (92) and rubber sealing rings (91) arranged on both sides of the labyrinth seal (92).

6. The heat recovery device for ammonia synthesis according to claim 1, characterized in that: Rotating plates (272) perpendicular to the inserting plate (26) are rotatably provided on both sides of the inserting plate (26), and the plurality of rotating plates (272) are driven to deflect by the outgoing gas to form an inclined surface for guiding the outgoing gas diversion.

7. The heat recovery device for ammonia synthesis according to claim 6, characterized in that: It also includes an upper plate (271) and a lower plate (273) which are fixedly arranged on the inserting plate (26) and used for limiting the rotation direction of the rotating plate (272).

8. The heat recovery device for ammonia synthesis according to claim 6, characterized in that: The two rotating plates (272) are symmetrically arranged, and after deflection, the rotating plates (272) form an eight-shaped structure with a wide opening facing the axis of the cavity (2).

9. The heat recovery device for ammonia synthesis according to claim 6, characterized in that: The invention also includes an elastic member (276) which is arranged on the rotating plate (272) and is used to keep the rotating plate (272) at a fixed angle.

10. The heat recovery device for ammonia synthesis according to claim 1, characterized in that: It also includes an ammonia synthesis water cooler (101) for receiving the output gas of the cavity (2), and a control valve is provided on the water cooler.

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