Heat exchanger and fixed bed radial reactor
By optimizing the structure of the heat exchanger and fixed-bed radial reactor, the problems of space utilization and thermal stress were solved, achieving efficient heat transfer and stable reaction temperature, and increasing the catalyst loading and equipment life.
Patent Information
- Application Number
- CN202520275870.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-20
- Publication Date
- 2026-01-09
- Estimated Expiration
- 2035-02-20
AI Technical Summary
Existing heat transfer heat exchangers cannot simultaneously address the issues of small footprint, reduced thermal stress, and high heat transfer efficiency, resulting in low utilization of effective space within the reactor and difficulty in eliminating thermal stress.
A heat exchanger comprising an outer shell, a planar tube sheet, a collection tank, a discharge pipe, and heat exchange tubes was designed. It adopts an ellipsoidal collection tank and heat exchange tubes with a bent section structure, combined with the inner shell and catalyst bed design of a fixed-bed radial reactor, to optimize space utilization and thermal stress relief.
The increased catalyst loading in the fixed-bed reactor enhanced heat transfer efficiency, stabilized reaction temperature, extended equipment lifespan, and improved gas distribution uniformity.
Smart Images
Figure CN223783449U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a heat exchanger and a fixed-bed radial reactor. Background Technology
[0002] In the gas purification processes of coal chemical industrial production facilities both domestically and internationally, reactor structures are classified into two types based on the method of removing reaction heat: adiabatic reactors and isothermal reactors. In isothermal reactors, heat transfer is mainly achieved through heat exchange tubes (heat exchange plate boxes). The two ends of the tube (plate) type heat transfer heat exchange tubes can be connected in the form of ring tubes, spherical (elliptical) cavities, or tube sheets.
[0003] Among them, the heat transfer tubes for heat transfer in reaction are connected at both ends in a loop. Due to the influence of the specifications of the loop tubes, the tube area for heat transfer is limited. If the specifications of the loop tubes are small, the tube area is insufficient, and if the specifications are large, the space occupied is large, which reduces the effective usable space in the reactor.
[0004] The heat transfer tubes for reaction heat transfer are connected at both ends in the form of spherical (elliptical) cavities. Although the tube area of the heat transfer tubes is guaranteed, it occupies a large amount of effective space inside the reactor.
[0005] If the two ends of the heat transfer tube are connected by tube sheets, it is difficult to eliminate the thermal stress of the heat transfer loop tube if fixed tube sheets are used at both ends. In order to eliminate the thermal stress of the tube, the shape of the heat transfer tube is more complex. If one end is fixed and the other end is movable tube sheet, the thickness of the tube sheet is increased. Utility Model Content
[0006] The technical problem to be solved by this invention is to address the issue that existing heat exchangers cannot simultaneously achieve small footprint, improved thermal stress, and high heat transfer efficiency. This invention provides a heat exchanger and a fixed-bed radial reactor. The heat exchanger of this invention occupies a small space, thereby increasing the amount of catalyst loaded in the fixed-bed reactor. At the same time, it has high heat transfer efficiency, which stabilizes the reaction temperature in the fixed-bed reactor. Moreover, the heat exchanger has a high thermal stress relief capability.
[0007] The present invention solves the above-mentioned technical problems through the following technical solution:
[0008] This utility model discloses a heat exchanger, which includes a shell, a planar tube sheet, a liquid collection tank, a discharge pipe, a feed pipe, and a plurality of heat exchange tubes;
[0009] The planar tube sheet is connected to the inner wall of the outer shell, and the planar tube sheet divides the inner cavity of the outer shell into two independent upper and lower inner cavities, namely a first inner cavity and a second inner cavity.
[0010] The discharge pipe is disposed in the first inner cavity, one end of the discharge pipe is connected to the planar tube plate and communicates with the second inner cavity, and the other end of the discharge pipe is connected to the outer shell and communicates with the outside of the outer shell;
[0011] The heat exchange tube and the liquid collection tank are disposed in the second inner cavity. One end of the heat exchange tube is connected to the liquid collection tank, and the other end of the heat exchange tube is connected to the planar tube sheet and communicates with the first inner cavity.
[0012] The liquid collection tank has an ellipsoidal structure and is provided with a first heat exchange medium inlet; a heat exchange medium outlet is provided on the outer shell at the top of the first inner cavity; a material inlet and a second heat exchange medium inlet are provided on the outer shell at the bottom of the second inner cavity; the first heat exchange medium inlet and the second heat exchange medium inlet are connected through the feed pipe.
[0013] This invention can save effective space inside the reactor while exchanging heat, and can also better eliminate thermal stress.
[0014] In some embodiments of this utility model, the major axis of the ellipsoidal liquid collection tank is perpendicular to the surface of the planar tube sheet, which increases the utilization area of the openings of the heat exchange tubes in the liquid collection tank, and also facilitates the entry of maintenance personnel during maintenance.
[0015] In some embodiments of this utility model, multiple turns of heat exchange tube units are sequentially connected from the top to the bottom of the liquid collection tank. Each turn of the heat exchange tube unit includes multiple heat exchange tubes spaced apart circumferentially along the liquid collection tank. Preferably, the distance between two adjacent turns of the heat exchange tube units along the axial direction of the liquid collection tank is 1.5 to 3.0 times the outer diameter of the heat exchange tube. Preferably, the spacing between two adjacent heat exchange tubes in each turn of the heat exchange tube unit is 1.5 to 3.0 times the outer diameter of the heat exchange tube.
[0016] In some embodiments of this utility model, the heat exchange tube includes a bent section and a vertical section that are interconnected. The bent section is also connected to the liquid collection tank, and the vertical section is also connected to the planar tube sheet. The vertical section is provided with a bent structure to improve the thermal stress deformation of the heat exchange tube.
[0017] Preferably, the bent section is a V-shaped structure, and the bent structure is a U-shaped structure.
[0018] In some embodiments of this utility model, the planar tube sheet includes a plate body, on which a first hole and a third hole are provided. The other end of the heat exchange tube communicates with the first hole, and the third hole is connected to one end of the discharge tube.
[0019] Preferably, the planar tube sheet is further provided with a second hole for replenishing the catalyst, and the second hole is spaced apart from the first hole.
[0020] In some embodiments of this utility model, the plate body is a disc-shaped structure.
[0021] In some embodiments of this invention, the first heat exchange medium inlet is located at the bottom of the liquid collection tank.
[0022] In some embodiments of this utility model, the feed pipe is disposed in the second heat exchange medium inlet, and an annular gap is provided between the outer wall of the feed pipe and the second heat exchange medium inlet to reduce the impact of thermal stress deformation of the heat exchange medium feed pipe on the outer shell, and a sealing ring is provided in the annular gap.
[0023] When the aforementioned heat exchanger is used for heat exchange, the heat exchange method specifically includes the following steps:
[0024] Material is introduced into the second inner cavity through the material inlet, and heat exchange medium is introduced into the liquid collection tank through the feed pipe. After heat exchange, the material and the heat exchange medium are discharged from the discharge pipe and the heat exchange medium outlet, respectively.
[0025] In this invention, the heat exchange medium enters the heat exchanger and exchanges heat with the reaction medium outside the heat exchange tubes. The heat exchange medium in this invention is conventional in the art, such as water.
[0026] When the heat exchange medium is water, it is pressed in from the bottom of the shell. When the heat exchange medium fills the heat exchanger, it exchanges heat with the reaction medium outside the heat exchanger and its temperature rises. A certain operating pressure of the heat exchange medium is set and controlled to keep the heat exchange medium in a saturated state, that is, the temperature rises. The heat exchange medium is in a supersaturated state and vaporization occurs. According to its density difference, the saturated medium with higher temperature and lower density automatically rises and leaves the heat exchange tube. The lower heat exchange medium continuously replenishes the heat exchange, so that the temperature of the reactants outside the heat exchange tube remains in a stable state (i.e., isothermal state).
[0027] This utility model also discloses a fixed-bed radial reactor, which includes an inner shell, a manifold, and the aforementioned heat exchanger;
[0028] The inner shell is disposed in the second inner cavity, and a plurality of first gas flow ports are provided on the shell wall of the inner shell, the first gas flow ports being connected to the material inlet; the top of the inner shell is connected to the planar tube sheet, and the liquid collection tank and the heat exchange tube are disposed in the inner shell;
[0029] The manifold is located in the inner shell, with one end connected to the top of the liquid collection tank and the other end connected to the discharge pipe. A second annular channel is formed between the outer wall of the manifold, the outer wall of the liquid collection tank, the inner wall of the inner shell, and the planar tube sheet for filling the catalyst bed. The heat exchange tube is arranged around the manifold and located in the second annular channel. A second gas flow port is provided on the tube wall of the manifold located in the inner shell.
[0030] In some embodiments of this invention, a first annular channel is provided between the outer side wall of the inner shell and the inner side wall of the outer shell, and a gap is provided between the bottom wall of the inner shell and the bottom wall of the outer shell. The first annular channel makes the gas distribution more uniform, and the gap buffers the incoming reaction gas, so that the gas flow rate is stable and uniform when the gas flows to the first gas flow port of the inner shell.
[0031] In some embodiments of this utility model, the first gas flow port is disposed on the side wall of the inner shell, and the first gas flow port is disposed at equal intervals along the circumference of the inner shell.
[0032] In some embodiments of this utility model, the inner shell is a shell that is open at one end and closed at the other end, with the open end connected to the planar tube plate and the closed end being an outwardly convex curved structure.
[0033] In some embodiments of this utility model, the outer shell includes a shell body and an upper end cap and a lower end cap disposed at both ends of the shell body. The lower end cap is connected to the shell body via a flange. The inner shell is provided with a discharge port, which is disposed on the bottom wall of the inner shell. A discharge pipe is provided on the discharge port, and the discharge pipe is located in the outer shell to avoid the influence of thermal stress deformation on the outer shell when the discharge pipe passes through the outer shell.
[0034] Preferably, both the upper and lower end caps are convex curved structures; preferably, the upper end cap is integrally formed with the shell body.
[0035] The number of unloading pipes is set according to the actual working conditions. In some embodiments of this utility model, there are two unloading pipes, which are symmetrically arranged around the center of the inner shell.
[0036] In some embodiments of this utility model, the upper end cap is provided with a manhole.
[0037] In some embodiments of this utility model, the outer shell is provided with an outer shell feeding port, and the inner shell is provided with an inner shell feeding port; a feeding pipe is connected to the outer shell feeding port and the inner shell feeding port, one end of the feeding pipe is located in the second annular channel, the other end of the feeding pipe is located outside the outer shell, and the feeding pipe is inclined towards the bottom of the inner shell.
[0038] The number of feeding tubes is set according to the actual working conditions. In some embodiments of this utility model, there are four feeding tubes, which are equally spaced along the circumference of the outer shell.
[0039] In some embodiments of this invention, the fixed-bed radial reactor further includes a gas guide component. The gas guide component is a cylindrical structure, fitted within the inner shell. The cylindrical wall of the gas guide component has several guide grooves protruding inwards. A third gas flow port is provided on the side of each guide groove, with its opening direction parallel to the tangential direction of the gas guide component. This allows gas entering the guide grooves to flow out from the third gas flow port while closely adhering to the side wall of the gas guide component. Changing the gas flow direction makes the gas entering the catalyst bed more evenly dispersed and also supports the catalyst bed.
[0040] Preferably, the guide groove is a quarter-spherical protrusion, and the side of the protrusion is open to form the gas flow port.
[0041] Preferably, multiple concentric guide groove units are provided along the axial direction of the gas guide member, and each concentric guide groove unit includes multiple guide grooves spaced apart circumferentially along the gas guide member.
[0042] More preferably, the spacing between two adjacent flow guide units is 50~500mm.
[0043] More preferably, the spacing between two adjacent guide channels in each circle of the guide channel unit is 50~500mm.
[0044] Preferably, a connector is provided between the gas guide and the inner shell, and a gap is provided between the outer wall of the gas guide and the inner wall of the inner shell, with the connector located in the gap. The gap serves as a buffer space for the gas, allowing the gas to enter the guide channel more evenly and stably. The connector can be made of square steel.
[0045] In some embodiments of this utility model, the fixed-bed radial reactor further includes a gas distribution pipe, which is sleeved outside the manifold. The gas distribution pipe is provided with a fourth gas flow port, and a third annular channel is provided between the inner wall of the gas distribution pipe and the outer wall of the manifold.
[0046] In some embodiments of this utility model, the fixed-bed radial reactor further includes a catalyst bed support, which includes an inner support and an outer support. The outer support is fitted inside the inner shell, with its top connected to the planar tube sheet and its bottom connected to the collection tank. The inner support is fitted outside the manifold, with its top connected to the planar tube sheet and its bottom connected to the collection tank. The annular section between the inner and outer supports forms the second annular channel, and both the inner and outer supports are provided with perforated structures.
[0047] Preferably, both the inner support and the outer support are wire mesh structures.
[0048] Preferably, when the aforementioned gas guide and gas distribution pipe are provided, the outer support is sleeved inside the gas guide and the inner support is sleeved outside the gas distribution pipe.
[0049] When using the aforementioned fixed-bed radial reactor, the operation method includes the following steps:
[0050] A catalyst bed is packed in the second annular channel; the heat exchange medium flows out from the heat exchange medium outlet after passing through the feed pipe, the collection tank, the heat exchange tube and the first inner cavity in sequence; the reactant enters from the material inlet and enters the catalyst bed in sequence through the first gas flow port along the radial direction of the shell for reaction, and the reacted material flows out through the second gas flow port and the discharge pipe in sequence.
[0051] The fixed-bed radial reactor of this invention can be used for carbon monoxide conversion, hydrogenation synthesis, and organic dehydrogenation reactions in coal chemical production.
[0052] In some embodiments of this invention, when the reaction is a methanol synthesis reaction, the reactants are a mixture of H2 and CO gases; the flow rate of the reactants is preferably 8000~9500 kmol / h, for example 8900 kmol / h; the reaction temperature is preferably 205℃~255℃; the heat exchange medium is preferably water; and the temperature of the heat exchange medium entering the feed pipe is preferably 190~240℃.
[0053] The positive and progressive effects of this utility model are as follows:
[0054] (1) When the heat exchanger of this utility model is used in a fixed-bed radial reactor, the fixed-bed radial reactor has a high volume utilization rate and a large amount of catalyst loading and production capacity compared with reactors of the same specifications.
[0055] (2) The heat exchanger of this utility model has a simple structure, good thermal stress relief, and long service life.
[0056] (3) The fixed-bed radial reactor of this invention has high heat exchange efficiency and stable and controllable reaction temperature, which makes the catalyst selection performance stable and the catalytic reaction conversion rate high. Furthermore, the fixed-bed radial reactor of this invention can improve the uniformity of gas distribution, making the catalytic reaction more stable.
[0057] (4) The fixed-bed radial reactor of this utility model can be adapted to the needs of different production properties. The equipment structure is simple and the process flow is simple. Attached Figure Description
[0058] Figure 1 This is a schematic diagram of the structure of the fixed-bed radial reactor described in an embodiment of this utility model.
[0059] Figure 2 This is a schematic diagram of the heat exchanger described in an embodiment of the present utility model.
[0060] Figure 3 for Figure 1 Enlarged view of section I.
[0061] Figure 4 for Figure 2 Cross-sectional view of the gas guide component.
[0062] Figure 5 for Figure 1 Enlarged view of Part II.
[0063] Figure 6 This is a partial front view of the gas guide component.
[0064] Figure 7 This is a schematic diagram of the heat exchange tube structure.
[0065] Figure 8 This is a schematic diagram of the heat exchange tube from another perspective.
[0066] Explanation of reference numerals in the attached figures:
[0067] 1-Outer shell, 2-Inner shell, 4-Collector, 5-Gas guide, 6-Gas distribution pipe, 8-Catalyst bed, 9-Discharge pipe, 10-Feeding pipe, 11-First annular channel, 12-Gap, 13-Second annular channel, 14-Connector, 15-Third annular channel;
[0068] 101-Heat exchange medium outlet, 102-Material outlet, 103-Second heat exchange medium inlet, 104-Material inlet, 105-Manhole, 106-Lower head, 107-Flange;
[0069] 201 - First gas flow port, 202 - Discharge port;
[0070] 301 - Planar tube sheet, 3011 - First hole, 3012 - Second hole, 3013 - Third hole;
[0071] 302 liquid collection tank, 3021 - first heat exchange medium inlet;
[0072] 303 - Heat exchange tube, 3031 - Bent section, 3032 - Vertical section;
[0073] 304 - discharge pipe, 305 - inlet pipe;
[0074] 401 - Second gas flow port;
[0075] 501 - Flow guide channel, 502 - Third gas flow port;
[0076] 601 - Fourth gas flow port;
[0077] 701 - Inner support component, 702 - Outer support component. Detailed Implementation
[0078] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.
[0079] Example 1
[0080] This embodiment discloses a heat exchanger, such as Figure 2 As shown, it includes an outer shell 1, a flat tube sheet 301, a liquid collection tank 302, several heat exchange tubes 303, a discharge pipe 304, and a feed pipe 305.
[0081] The planar tube sheet 301 includes a plate body with a disc-shaped structure. The plate body is provided with a first hole 3011, a second hole 3012 and a third hole 3013. The second hole 3012 is used to replenish the catalyst. The second hole 3012 is spaced apart from the first hole 3011. The third hole 3013 is located at the center of the plate body.
[0082] The liquid collection tank 302 has an ellipsoidal structure, and the major axis of the ellipsoidal liquid collection tank is perpendicular to the planar tube sheet 301. The bottom of the liquid collection tank 302 is provided with a first heat exchange medium inlet 3021.
[0083] One end of several heat exchange tubes 303 is connected to the liquid collection tank 302, and the other end of several heat exchange tubes 303 is connected to the first hole 3011.
[0084] Multiple coils of heat exchange tube units are sequentially connected from top to bottom along the liquid collection tank 302. Each coil of heat exchange tube unit includes multiple heat exchange tubes 303 spaced circumferentially along the liquid collection tank 302. The distance between two adjacent coils of heat exchange tube units along the axial direction of the liquid collection tank is 1.5 to 3.0 times the outer diameter of the heat exchange tubes, and the spacing between two adjacent heat exchange tubes in each coil of heat exchange tube unit is 1.5 to 3.0 times the outer diameter of the heat exchange tubes.
[0085] The heat exchange tube 303 includes a bent section 3031 and a vertical section 3032 that are interconnected. The bent section 3031 is also connected to the liquid collection tank 302, and the vertical section 3032 is also connected to the flat tube sheet 301. The bent section 3031 has a V-shaped structure, and the vertical section 3032 is provided with a bent structure, which is U-shaped.
[0086] The outer shell 1 includes a shell body and upper and lower end caps located at both ends of the shell body. The upper end cap is integrally formed with the shell body, and the lower end cap 106 is connected to the shell body via a flange 107. Both the upper and lower end caps 106 are convex curved surface structures. The outer shell 1 is provided with a heat exchange medium outlet 101, a material outlet 102, a second heat exchange medium inlet 103, a material inlet 104, a shell feed port, and a manhole 105.
[0087] The side of the flat tube sheet 301 is connected to the inner wall of the outer shell 1. The flat tube sheet 301 divides the inner cavity of the outer shell 1 into two independent upper and lower inner cavities, namely the first inner cavity and the second inner cavity. The heat exchange medium outlet 101 and the material outlet 102 are located on the outer shell 1 in the first inner cavity area, and the second heat exchange medium inlet 103 and the material inlet 104 are located on the outer shell 1 in the second inner cavity area.
[0088] The discharge pipe 304 is located in the first inner cavity. One end of the discharge pipe 304 is connected to the third hole 3013, and the other end of the discharge pipe 304 is connected to the material outlet 102.
[0089] One end of the feed pipe 305 is connected to the first heat exchange medium inlet 3021, and the other end of the feed pipe 305 is connected to the second heat exchange medium inlet 103. The feed pipe 305 connects the liquid collection tank 302 and the outside of the outer shell 1. An annular gap is provided between the outer wall of the feed pipe 305 and the second heat exchange medium inlet, and a sealing ring is provided in the annular gap.
[0090] Example 2
[0091] This embodiment discloses a fixed-bed radial reactor, such as Figures 1-8 As shown, it includes the heat exchanger of Embodiment 1, inner shell 2, manifold 4, gas guide 5, gas distribution pipe 6, unloading pipe 9, feeding pipe 10, first annular channel 11, interval 12, second annular channel 13, connector 14 and third annular channel 15.
[0092] The inner shell 2 is a shell that is open at one end and closed at the other. The open end is connected to the planar tube plate 301, and the closed end is a curved structure that bulges outward. The inner shell 2 is provided with a first gas flow port 201, a discharge port 202, and an inner shell feeding port. The first gas flow port 201 is located on the side wall of the inner shell 2 and is evenly distributed along the circumference of the inner shell 2. The discharge port 202 is located on the bottom wall of the inner shell 2 and is connected to a discharge pipe 9. The other end of the discharge pipe 9 is located in the outer shell 1. In this example, there are two discharge pipes 9, which are symmetrically arranged around the center of the inner shell 2.
[0093] The inner shell 2 is disposed in the second inner cavity. A first annular channel 11 is provided between the outer side wall of the inner shell 2 and the inner side wall of the outer shell 1. A gap 12 is provided between the bottom wall of the inner shell 2 and the bottom wall of the outer shell 1. The material inlet 104 on the outer shell 1 is connected to the first gas flow port 201 through the gap 12 and the first annular channel 11. The top of the inner shell 2 is connected to the bottom surface of the planar tube sheet 301. The liquid collection tank 302 and the heat exchange tube 303 are disposed in the inner shell 2.
[0094] One end of the manifold 4 is located in the inner shell 2 and connected to the top of the liquid collection tank 302, and the other end of the manifold 4 is connected to the discharge pipe 304; the heat exchange pipe 303 is arranged around the manifold 4 and located in the second annular channel 13, and the second gas flow port 401 is provided on the pipe wall of the manifold 4 located in the inner shell 2.
[0095] The gas guide 5 has a cylindrical structure and is fitted inside the inner shell 2. The cylindrical wall of the gas guide 5 has several guide grooves 501 protruding into the interior of the gas guide 5. A third gas flow port 502 is formed on the side of each guide groove 501, and the opening direction of the third gas flow port 502 is parallel to the tangential direction of the gas guide 5, allowing gas entering the guide groove 501 to flow out from the third gas flow port 502 while adhering closely to the side wall of the gas guide 5. Specifically, in this embodiment, the guide groove 501 is a quarter-spherical protrusion, and the open side of the protrusion forms the third gas flow port 502.
[0096] Multiple rings of guide groove units are arranged along the axial direction of the gas guide member 5. Each ring of guide groove unit includes multiple guide grooves 501 arranged at intervals along the circumference of the gas guide member. The spacing between two adjacent rings of guide groove units is 50~500mm, and the spacing between two adjacent guide grooves 501 in each ring of guide groove unit is 50~500mm.
[0097] A connector 14 is connected between the gas guide 5 and the inner shell 2. A gap is provided between the outer wall of the gas guide 5 and the inner wall of the inner shell 2. The connector 14 is located in the gap. The gap serves as a buffer space for the gas, allowing the gas to enter the guide groove 501 more evenly and stably. In this embodiment, the connector 14 is a square steel.
[0098] The gas distribution pipe 6 is sleeved on the outside of the manifold 4. The gas distribution pipe 6 is provided with a fourth gas flow port 601. A third annular channel 15 is provided between the inner wall of the gas distribution pipe 6 and the outer wall of the manifold for gas buffering.
[0099] like Figure 3 and Figure 6 As shown, the catalyst bed support includes an inner support 701 and an outer support 702. The outer support 702 is fitted inside the gas guide 5. The top of the outer support 702 is connected to the planar tube sheet 301, and the bottom of the outer support 702 is connected to the liquid collection tank 302. The bottom of the outer support 702 is a convex arc-shaped surface that matches the shape of the lower end cap of the inner shell 2. The inner support 701 is fitted outside the gas distribution pipe 6. The top of the inner support 701 is connected to the planar tube sheet 301, and the bottom of the inner support 701 is connected to the liquid collection tank 302. Both the inner support 701 and the outer support 702 are stainless steel wire mesh structures. A second annular channel 13 for filling the catalyst bed 8 is formed between the inner support 701, the outer support 702, and the planar tube sheet 301.
[0100] One end of the feed pipe 305 is connected to the first heat exchange medium inlet 3021, and the other end extends through the bottom of the inner shell 2 and the second heat exchange medium inlet 103 on the outer shell 1 to the outside of the outer shell 1.
[0101] A feeding pipe 10 is connected to the outer shell feeding port and the inner shell feeding port. One end of the feeding pipe 10 is located in the second annular channel, and the other end of the feeding pipe 10 is located outside the outer shell 1. The feeding pipe 10 is inclined towards the bottom of the inner shell 2. In this embodiment, there are four feeding pipes 10, which are equally spaced along the circumference of the outer shell 1.
[0102] The specifications and dimensions of each component are as follows:
[0103] Upper end cap of outer shell 1: DN2600mm; Lower end cap 106 of outer shell 1: DN2600mm; Shell body of outer shell 1: DN2600mm; Flange 107: DN2600mm; Inner shell 2: φ2420mm; Gas distribution pipe 6: φ600mm; Lower end cap of inner shell 2: DN2400mm; Manifold 4: DN450mm; Heat exchange tube 303: L8500mm; Flat tube sheet 301: DN2600mm; Liquid collection tank 302: DN800mm; Material inlet 104: DN250mm; Discharge pipe 304: DN400mm; Feed pipe 305: DN500mm; Heat exchange medium outlet 101: DN400mm; Manhole 105: DN500mm; Feed pipe 10: DN400mm; Discharge pipe 9: φ300; Second hole 3012: DN50mm.
[0104] Example 3
[0105] This embodiment uses the fixed-bed radial reactor of Example 2 to synthesize methanol. The reaction pressure in this embodiment is 5.5 MPa, the main components of the feed gas are H2 and CO, the flow rate of the feed gas is 8900 kmol / h, the chemical reaction of methanol synthesis is CO + H2 → CH3OH + Q↑, and the reaction temperature needs to be controlled between 210 and 260℃.
[0106] Specifically, the following steps are included:
[0107] The catalyst bed 8 is filled in the second annular channel 13. After the raw material gas enters from the material inlet 104, it enters the catalyst bed 8 through the first gas flow port 201 in the radial direction of the outer shell 1 for reaction. The reacted material flows out from the material outlet 102 after passing through the fourth gas flow port 601 on the gas distribution pipe 6, the second gas flow port 401 on the collection pipe 4, and the discharge pipe 304.
[0108] The heat exchange medium flows out from the heat exchange medium outlet 101 after passing through the feed pipe 305, the liquid collection tank 302, the heat exchange tube 303 and the first inner cavity in sequence.
[0109] The heat exchange medium is water. After heat exchange, the hot water heats up to a mixture of supersaturated steam and supersaturated water. Due to the density difference, the mixture naturally rises along the heat exchange tube 303 into the first inner cavity, and then exits from the heat exchange medium outlet 101, entering the external steam drum of the reactor to produce saturated steam as a byproduct. The steam production pressure of the external equipment steam drum is 1.4–3.5 MPa, and the saturated steam temperature is 195℃–245℃ (heat exchange temperature difference of approximately 15℃).
[0110] The syngas produced after the methanol synthesis reaction is at approximately 205–255°C.
[0111] It can be seen that the fixed-bed radial reactor in the above embodiment has high heat exchange efficiency and stable reaction temperature.
[0112] The specific embodiments described above in conjunction with the accompanying drawings and one example of the present utility model are specific support for the technical concept of the present utility model, and should not be construed as limiting the scope of protection of the present utility model. Any equivalent changes or modifications made based on the technical concept proposed by the present utility model and on the basis of the technical solution shall still fall within the scope of protection of the technical solution of the present utility model.
Claims
1. A heat exchanger, characterized in that, It includes an outer shell, a flat tube sheet, a liquid collection tank, a discharge pipe, a feed pipe, and several heat exchange tubes; The planar tube sheet is connected to the inner wall of the outer shell, and the planar tube sheet divides the inner cavity of the outer shell into two independent upper and lower inner cavities, namely a first inner cavity and a second inner cavity. The discharge pipe is disposed in the first inner cavity, one end of the discharge pipe is connected to the planar tube plate and communicates with the second inner cavity, and the other end of the discharge pipe is connected to the outer shell and communicates with the outside of the outer shell; The heat exchange tube and the liquid collection tank are disposed in the second inner cavity. One end of the heat exchange tube is connected to the liquid collection tank, and the other end of the heat exchange tube is connected to the planar tube sheet and communicates with the first inner cavity. The liquid collection tank has an ellipsoidal structure and is provided with a first heat exchange medium inlet; a heat exchange medium outlet is provided on the outer shell at the top of the first inner cavity; a material inlet and a second heat exchange medium inlet are provided on the outer shell at the bottom of the second inner cavity; the first heat exchange medium inlet and the second heat exchange medium inlet are connected through the feed pipe.
2. The heat exchanger as described in claim 1, characterized in that, The major axis of the ellipsoidal liquid collection tank is perpendicular to the surface of the planar tube sheet; Multiple turns of heat exchange tube units are sequentially connected from the top to the bottom of the liquid collection tank. Each turn of the heat exchange tube unit includes multiple heat exchange tubes spaced apart circumferentially along the liquid collection tank. The distance between two adjacent turns of the heat exchange tube units along the axial direction of the liquid collection tank is 1.5 to 3.0 times the outer diameter of the heat exchange tube. The spacing between two adjacent heat exchange tubes in each turn of the heat exchange tube unit is 1.5 to 3.0 times the outer diameter of the heat exchange tube.
3. The heat exchanger as described in claim 1, characterized in that, The heat exchange tube includes a bent section and a vertical section that are interconnected. The bent section is also connected to the liquid collection tank, and the vertical section is also connected to the planar tube sheet. The vertical section is provided with a bending structure. The bent section is a V-shaped structure, and the bending structure is a U-shaped structure. The planar tube sheet includes a plate body, on which a first hole and a third hole are provided. The other end of the heat exchange tube is connected to the first hole, and the third hole is connected to one end of the discharge tube. The planar tube sheet is also provided with a second hole, which is spaced apart from the first hole. The first heat exchange medium inlet is located at the bottom of the liquid collection tank; The feed pipe is disposed in the inlet of the second heat exchange medium, and an annular gap is provided between the outer wall of the feed pipe and the inlet of the second heat exchange medium, and a sealing ring is provided in the annular gap.
4. A fixed-bed radial reactor, characterized in that, It includes an inner shell, a manifold, and a heat exchanger as described in any one of claims 1 to 3; The inner shell is disposed in the second inner cavity, and a plurality of first gas flow ports are provided on the shell wall of the inner shell, the first gas flow ports being connected to the material inlet; the top of the inner shell is connected to the planar tube sheet, and the liquid collection tank and the heat exchange tube are disposed in the inner shell; The manifold is located in the inner shell, with one end connected to the top of the liquid collection tank and the other end connected to the discharge pipe. A second annular channel is formed between the outer wall of the manifold, the outer wall of the liquid collection tank, the inner wall of the inner shell, and the planar tube sheet. The heat exchange tube is arranged around the manifold and located in the second annular channel. A second gas flow port is provided on the wall of the manifold located in the inner shell.
5. The fixed-bed radial reactor as described in claim 4, characterized in that, A first annular channel is provided between the outer side wall of the inner shell and the inner side wall of the outer shell, and a gap is provided between the bottom wall of the inner shell and the bottom wall of the outer shell. The first gas flow port is disposed on the side wall of the inner shell, and the first gas flow port is disposed at equal intervals along the circumference of the inner shell; The inner shell is a shell that is open at one end and closed at the other end. The open end is connected to the planar tube sheet, and the closed end is a curved structure that bulges outward. The outer shell includes a shell body and upper and lower end caps disposed at both ends of the shell body. The lower end caps are connected to the shell body via flanges. The inner shell is provided with a discharge port, which is located on the bottom wall of the inner shell. A discharge pipe is provided on the discharge port, and the discharge pipe is located inside the outer shell. The outer shell is provided with an outer shell feeding port, and the inner shell is provided with an inner shell feeding port; a feeding pipe is connected to the outer shell feeding port and the inner shell feeding port, one end of the feeding pipe is located in the second annular channel, the other end of the feeding pipe is located outside the outer shell, and the feeding pipe is inclined towards the bottom of the inner shell.
6. The fixed-bed radial reactor as described in claim 4, characterized in that, The fixed-bed radial reactor further includes a gas guide, which is a cylindrical structure and is fitted inside the inner shell. The cylindrical wall of the gas guide has several guide grooves protruding into the interior of the gas guide. A third gas flow port is provided on the side of the guide groove. The opening direction of the third gas flow port is parallel to the tangential direction of the gas guide, so that the gas entering the guide groove flows out from the third gas flow port while closely adhering to the side wall of the gas guide.
7. The fixed-bed radial reactor as described in claim 6, characterized in that, The guide channel is a quarter-spherical protrusion, and the side of the protrusion is open to form the gas flow port; Multiple concentric guide groove units are provided along the axial direction of the gas guide member, and each concentric guide groove unit includes multiple guide grooves spaced apart circumferentially along the gas guide member; more preferably, the spacing between two adjacent concentric guide groove units is 50~500mm; more preferably, the spacing between two adjacent guide grooves in each concentric guide groove unit is 50~500mm. A connector is provided between the gas guide and the inner shell. A gap is provided between the outer wall of the gas guide and the inner wall of the inner shell, and the connector is located in the gap.
8. The fixed-bed radial reactor as described in claim 4, characterized in that, The fixed-bed radial reactor further includes a gas distribution pipe, which is sleeved outside the manifold. The gas distribution pipe is provided with a fourth gas flow port, and a third annular channel is provided between the inner wall of the gas distribution pipe and the outer wall of the manifold.
9. The fixed-bed radial reactor as described in claim 4, characterized in that, The fixed-bed radial reactor further includes a catalyst bed support, which comprises an inner support and an outer support. The outer support is fitted inside the inner shell, with its top connected to the planar tube sheet and its bottom connected to the collection tank. The inner support is fitted outside the manifold, with its top connected to the planar tube sheet and its bottom connected to the collection tank. The annular section between the inner and outer supports forms the second annular channel, and both the inner and outer supports are provided with perforated structures.
10. The fixed-bed radial reactor as described in claim 9, characterized in that, Both the inner support and the outer support are wire mesh structures; When a gas guide and a gas distribution pipe are provided, the gas guide is a cylindrical structure and is fitted inside the inner shell. The cylindrical wall of the gas guide has several guide grooves protruding into the interior of the gas guide. A third gas flow port is opened on the side of the guide groove. The opening direction of the third gas flow port is parallel to the tangential direction of the gas guide, so that the gas entering the guide groove flows out from the third gas flow port while closely adhering to the side wall of the gas guide. The outer support is fitted inside the gas guide. The gas distribution pipe is sleeved outside the manifold, and a fourth gas flow port is provided on the gas distribution pipe. A third annular channel is provided between the inner wall of the gas distribution pipe and the outer wall of the manifold, and the inner support is sleeved outside the gas distribution pipe.