Energy-saving heat exchange device for nitrate micro-channel reactor

Abstract

The invention relates to the technical field of heat exchange equipment, and provides an energy-saving heat exchange device for a mirabilite microchannel reactor, which comprises a microchannel reactor for performing mirabilite mixing reaction on materials, and a primary shell-and-tube heat exchanger and a secondary shell-and-tube heat exchanger for cooling the reacted materials in sequence, each of the first-stage shell-and-tube heat exchanger and the second-stage shell-and-tube heat exchanger comprises a shell; two rows of upper half-moon plates and lower half-moon plates which are distributed up and down are alternately arranged in a shell, the interior of the shell is divided by the upper half-moon plates and the lower half-moon plates to form a material guide area capable of enabling materials to advance in a wave mode in the shell, and splitter plates which are distributed perpendicular to the upper half-moon plates and the lower half-moon plates are arranged in the shell. The material guide area is divided into two roundabout material guide channels through the splitter plate, so that the circulation path of materials in the heat exchanger is increased, the materials can move forward in a roundabout mode in the channels, and the heat exchange efficiency of the heat exchange tube nest is improved.

Description

Technical Field

[0001] The invention relates to the technical field of heat exchange equipment, and in particular to an energy-saving heat exchange device for a nitrate microchannel reactor. Background Art

[0002] It is widely used in the production process of nitrate microchannel reactors in the chemical, pharmaceutical and other industries, and is of great significance for improving production efficiency, reducing energy consumption and ensuring product quality. During the operation of the nitrate microchannel reactor, efficient heat exchange is achieved. It can accurately control the temperature of the reaction system to ensure that the reaction is carried out under appropriate temperature conditions. Through rapid heat exchange, the heat generated by the reaction can be removed in time or the required heat can be provided, thereby improving the efficiency and selectivity of the reaction.

[0003] The existing energy-saving heat exchange for the nitrate microchannel reactor mostly adopts shell and tube heat exchangers, which are wall heat exchangers that use the wall of the tube bundle enclosed in the shell as the heat transfer surface. This type of heat exchanger has a simple structure and reliable operation. It can be made of various structural materials (mainly metal materials) and can be used under high temperature and high pressure. It is currently the most widely used type.

[0004] After searching, the bulletin number CN104949552B discloses a shell and tube heat exchanger, which is mainly composed of a shell, a tube box located on both sides of the shell, a tube sheet located between the tube box and the shell, and a heat exchange tube placed in the shell. A saddle is provided under the shell to fix the shell and tube heat exchanger on the ground or other equipment. The shell is usually cylindrical.

[0005] The above-mentioned shell and tube heat exchanger uses the intervally arranged arched plates and circular plates to force the coolant to flow through the central hole of the arched plate and then redirect to flow through the edge of the circular plate, so that the heat exchange tubes are fully cooled and the coolant is prevented from flowing linearly from one end of the shell to the other end. However, since the material always flows from one end to the other end, the heat exchange effect of the internal heat exchange tubes causes a large temperature difference at both ends of the shell and tube heat exchanger. Under the action of the temperature difference, the pressure resistance requirement of the shell and tube heat exchanger is relatively high. Summary of the invention

[0006] The invention provides an energy-saving heat exchange device for a nitrate microchannel reactor, which solves the problem of large temperature difference at both ends of a shell heat exchanger in the prior art.

[0007] The technical scheme of the present invention is as follows: an energy-saving heat exchange device for a nitrate microchannel reactor, comprising a microchannel reactor for performing a nitrate mixing reaction on materials, a primary shell and tube heat exchanger and a secondary shell and tube heat exchanger for sequentially cooling the materials after the reaction, wherein the primary shell and tube heat exchanger and the secondary shell and tube heat exchanger both comprise a shell, one end of the shell is provided with a feed inlet and a discharge inlet distributed up and down, a row of upper menisci and a row of lower menisci distributed up and down with the upper menisci are fixed inside the shell, and the upper menisci and the lower menisci are alternately arranged along the length direction of the shell, and the upper menisci A heat exchange component for cooling the material flowing through is arranged on the upper shell, and a water inlet and a water outlet communicated with the end of the heat exchange component are arranged on both sides of the upper meniscus, and the upper meniscus and the lower meniscus divide the shell into a material guide area that enables the material to move forward in a wave-like manner in the shell, and a diverter plate vertically distributed with the upper meniscus and the lower meniscus is fixed in the shell, and a notch is arranged at the bottom of one end of the diverter plate away from the feed port and the discharge port, and the diverter plate divides the material guide area into two circuitous material guide channels, and the feed port and the discharge port are both provided with diverters that can switch the flow direction of the material in the two material guide channels.

[0008] Preferably, the heat exchange assembly includes a plurality of heat exchange tubes distributed in an array on the upper meniscus. The upper meniscus located at both ends of the heat exchange tubes is a hollow structure and has circular holes on the sides that are respectively connected to the water inlet and the water outlet. The heat exchange tubes are connected to the inner cavity of the upper meniscus at both ends.

[0009] Preferably, the diverter includes an outer tube body, the outer tube body is fixed outside the shell, a partition is fixed inside the outer tube body, the upper end of the partition is fixedly connected to the diverter plate, an inner tube body is fixed on the partition, the partition separates the outer tube body and the inner tube body cavity to form two material guide channels leading to two material guide cavities respectively, and a movable plug and a driving component that drives the movable plug to slide up and down to guide the material to different material guide cavities are provided in the inner tube body.

[0010] Preferably, a stop ring and a sealing ring located below the stop ring are fixed in the inner tube body, a first flow port located between the stop ring and the sealing ring is opened on the inner tube body, and a second flow port located below the sealing ring is opened on the inner tube body, and the first flow port and the second flow port lead to two material guide chambers respectively.

[0011] Preferably, the movable plug includes an upper cone, a cylinder and a lower cone integrally formed from top to bottom, the cylinder and the lower cone are hollow inside, a plurality of annular guide holes are opened on the cylinder, a conduit is fixed at the bottom of the lower cone, and a guide cover is fixed at the bottom of the conduit.

[0012] Preferably, the diameter of the upper cone gradually decreases from top to bottom and fits with the inner wall of the inner tube body, the diameter of the lower cone gradually increases from top to bottom and fits with the inner wall of the inner tube body, and the diameter of the cylinder is equal to the bottom diameter of the upper cone and the top diameter of the lower cone.

[0013] Preferably, the diameter of the flow guide cover gradually increases from top to bottom and fits closely with the inner wall of the outer tube body.

[0014] Preferably, the driving assembly includes a first electromagnet, a spring and a second electromagnet, the first electromagnet is fixed on the inner bottom wall of the inner tube body, the second electromagnet is fixed on the bottom wall of the lower cone, the spring is sleeved outside the catheter, and the two ends of the spring are respectively fixed to the first electromagnet and the second electromagnet.

[0015] The beneficial effects of the present invention are: In the shell of the present invention, two rows of upper and lower menisci are alternately arranged, and the upper and lower menisci divide the shell into a material guide area that allows the material to move forward in a wave-like manner in the shell. A diverter plate is arranged in the shell and is vertically distributed with the upper and lower menisci. A notch is arranged at the bottom of one end of the diverter plate away from the feed port and the discharge port. The diverter plate divides the material guide area into two circuitous material guide channels, thereby increasing the flow path of the material in the heat exchanger, allowing the material to move forward in a circuitous manner in the channel, and improving the heat exchange efficiency of the heat exchange tubes. The present invention controls the height of the movable plugs in the feed port and the discharge port to switch the flow direction of the material guide channel by the flow divider, so that the material can move in a circuitous manner along different sides in the two material guide channels, thereby reducing the temperature difference of the material in the material guide channels on both sides, thereby keeping the temperature difference at both ends of the heat exchanger within a small range, and improving the cooling effect on the material, solving the problem of large temperature difference at both ends of the shell heat exchanger in the prior art; The outlet pipeline of the secondary shell and tube heat exchanger in the present invention is externally connected to a nitrogen supply system. When an abnormal situation occurs, the material at the outlet of the secondary shell and tube heat exchanger enters the downstream valve and is closed. The nitrogen valve is opened, and the nitrogen will flow back into the secondary shell and tube heat exchanger and the primary shell and tube heat exchanger, blowing the material in the two-stage heat exchanger out from the discharge pipeline to the emergency tank. The two-stage tubular reactor of the present invention adopts an indirect cooling method of tube-in-tube circulating water, which can take away the heat generated in the reaction process and control the reaction temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0017] Figure 1 A schematic diagram of the operation flow of an energy-saving heat exchange device for a nitrate microchannel reactor proposed by the present invention; Figure 2 It is a partial cross-sectional structural schematic diagram of an energy-saving heat exchange device for a nitrate microchannel reactor proposed by the present invention; Figure 3 This is a schematic diagram of the heat exchange component structure proposed by the present invention; Figure 4 A schematic diagram of a half-section structure of a flow divider proposed in the present invention; Figure 5 This is a schematic diagram of the structure of the mobile plug proposed by the present invention; Figure 6 This is a schematic diagram of the initial working state of the flow divider at the feed inlet and the discharge outlet proposed by the present invention; Figure 7 This is a schematic diagram of the working state of the flow divider at the feed inlet and the discharge outlet after switching proposed by the present invention; In the figure: 1. Shell; 11. Feed inlet; 12. Discharge outlet; 13. Water inlet; 14. Water outlet; 2. Upper meniscus; 21. Circular hole; 3. Lower meniscus; 4. Diverter; 41. Notch; 5. Diverter; 51. Outer tube body; 52. Inner tube body; 521. Stop ring; 522. Sealing ring; 523. First flow port; 524. Second flow port; 53. Partition; 54. Moving plug; 541. Upper cone; 542. Cylinder; 543. Lower cone; 544. Guide hole; 545. Conduit; 546. Flow guide cover; 55. Drive assembly; 551. First electromagnet; 552. Spring; 553. Second electromagnet; 6. Heat exchange tubes. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] See also Figure 1 and Figure 2The present invention provides a technical solution: an energy-saving heat exchange device for a nitrate microchannel reactor, comprising a microchannel reactor for performing a nitrate mixing reaction on materials, a primary shell and tube heat exchanger and a secondary shell and tube heat exchanger for sequentially cooling the materials after the reaction, the materials at the outlet of the microchannel reactor (temperature controlled at about 140°C) enter the primary shell and tube heat exchanger, the mixed materials after passing through the microchannel reactor enter the primary shell and tube heat exchanger for continuous reaction and cooling, and then enter the secondary shell and tube heat exchanger for continuous reaction and cooling, so as to improve the material conversion rate, wherein the chlorobenzene reaction conversion rate in the primary shell and tube heat exchanger is about 5%, the continuous reaction time is about 27s, and the chlorobenzene is basically completely converted, and the purpose of the secondary shell and tube heat exchanger is to cool and reduce the temperature, the feed temperature of the primary shell and tube heat exchanger is about 140°C, the discharge temperature of the secondary shell and tube heat exchanger is about 90°C, and the discharge temperature of the secondary shell and tube heat exchanger is about 55°C).

[0020] The outlet pipeline of the secondary shell and tube heat exchanger in the present invention is externally connected to a nitrogen supply system. When an abnormal situation occurs, the material at the outlet of the secondary shell and tube heat exchanger enters the downstream valve and is closed. The nitrogen valve is opened, and the nitrogen will flow back into the secondary shell and tube heat exchanger and the primary shell and tube heat exchanger to blow the material in the two-stage heat exchanger out from the discharge pipeline to the emergency tank.

[0021] It should be noted that the primary shell and tube heat exchanger and the secondary shell and tube heat exchanger in the present invention both include a shell 1, such as Figure 2 As shown, one end of the shell 1 is provided with a feed port 11 and a discharge port 12 distributed up and down, a row of upper menisci 2 and a row of lower menisci 3 distributed up and down with the upper menisci 2 are fixed inside the shell 1, and the upper menisci 2 and the lower menisci 3 are alternately arranged along the length direction of the shell 1, a heat exchange component for cooling the material flowing through is arranged on the upper meniscus 2, and a water inlet 13 and a water outlet 14 connected to the end of the heat exchange component are arranged on both sides of the upper meniscus 2, and the upper meniscus 2 and the lower meniscus 3 separate the shell 1 to form a material guide area that can make the material advance in a wave-like manner in the shell 1, and the shell 1 is fixed with a heat exchange component connected to the upper meniscus 2 and the lower meniscus 3. The diverter plate 4 is vertically distributed on the moon plate 3, and a notch 41 is provided at the bottom of one end of the diverter plate 4 away from the feed port 11 and the discharge port 12. The diverter plate 4 divides the material guide area into two circuitous material guide channels. The feed port 11 and the discharge port 12 are both provided with a diverter 5 capable of switching the flow direction of the material in the two material guide channels. The height of the movable plug 54 in the feed port 11 and the discharge port 12 is adjusted to achieve the switching of the flow direction of the material guide channel by the diverter 5, so that the material can be circuitously advanced in the two material guide channels along different sides, thereby reducing the temperature difference of the material in the material guide channels on both sides and improving the cooling effect on the material.

[0022] See also Figure 2 and Figure 3The heat exchange component includes a plurality of heat exchange tubes 6 distributed in an array on the upper meniscus 2. The upper meniscus 2 at both ends of the heat exchange tubes 6 are hollow structures and have round holes 21 on the sides thereof which are respectively connected to the water inlet 13 and the water outlet 14. The heat exchange tubes 6 are connected to the inner cavities of the upper meniscus 2 at both ends. The water inlet 13 is used to introduce circulating water, which is guided from the inner cavity of the upper meniscus 2 to the heat exchange tubes 6, and then from the upper meniscus 2 at the other end of the heat exchange tubes 6 to the water outlet 14, thereby completing the heat exchange.

[0023] See also Figure 2 and Figure 4 The flow divider 5 includes an outer tube body 51, which is fixed to the outside of the shell 1. A partition plate 53 is fixed inside the outer tube body 51. The upper end of the partition plate 53 is fixedly connected to the flow divider plate 4. An inner tube body 52 is fixed on the partition plate 53. The partition plate 53 separates the outer tube body 51 and the inner tube body 52 into two material guide channels. A movable plug 54 and a driving component 55 that drives the movable plug 54 to slide up and down to guide the material to different material guide cavities are arranged in the inner tube body 52.

[0024] A stop ring 521 and a sealing ring 522 below the stop ring 521 are fixed in the inner tube body 52. ​​The stop ring 521 is used to limit the upward movement of the movable plug 54, and the sealing ring 522 is used to seal the movable plug 54 when it moves up and down. The inner tube body 52 is provided with a first flow port 523 between the stop ring 521 and the sealing ring 522, and the inner tube body 52 is provided with a second flow port 524 below the sealing ring 522. The first flow port 523 and the second flow port 524 lead to two material guiding chambers respectively.

[0025] See also Figure 4 and Figure 5 The movable plug 54 includes an upper cone 541, a cylinder 542 and a lower cone 543 integrally formed from top to bottom. The cylinder 542 and the lower cone 543 are hollow inside, and a plurality of guide holes 544 distributed in an annular manner are opened on the cylinder 542. In a preferred embodiment, the diameter of the upper cone 541 gradually decreases from top to bottom and fits with the inner wall of the inner tube body 52, the diameter of the lower cone 543 gradually increases from top to bottom and fits with the inner wall of the inner tube body 52, the diameter of the cylinder 542 is equal to the bottom diameter of the upper cone 541 and the top diameter of the lower cone 543, a guide tube 545 is fixed at the bottom of the lower cone 543, and a guide cover 546 is fixed at the bottom of the guide tube 545. In a preferred embodiment, the diameter of the guide cover 546 gradually increases from top to bottom and fits with the inner wall of the outer tube body 51, so as to facilitate the introduction of the material at the bottom of the outer tube body 51 into the inner tube body 52.

[0026] The driving assembly 55 includes a first electromagnet 551, a spring 552 and a second electromagnet 553. The first electromagnet 551 is fixed to the inner bottom wall of the inner tube 52, the second electromagnet 553 is fixed to the bottom wall of the lower cone 543, the spring 552 is sleeved outside the guide tube 545, and the two ends of the spring 552 are respectively fixed to the first electromagnet 551 and the second electromagnet 553. Figure 4 The first electromagnet 551 and the second electromagnet 553 shown are in the power-off state. At this time, the guide hole 544 is located above the sealing ring 522. The material entering the inner cavity of the movable plug 54 through the guide cover 546 and the conduit 545 enters the inner tube body 52 through the guide hole 544, and is then guided to the material guide cavity on one side by the first flow port 523 at the upper part of the inner tube body 52. ​​When the first electromagnet 551 and the second electromagnet 553 are in the power-on state, the guide hole 544 is located below the sealing ring 522. The material entering the inner cavity of the movable plug 54 through the guide cover 546 and the conduit 545 enters the inner tube body 52 through the guide hole 544, and is then guided to the material guide cavity on the other side by the second flow port 524 at the lower part of the inner tube body 52.

[0027] The working principle and use process of the present invention are as follows: In the initial state, Figure 6 As shown, the movable plug 54 in the feed port 11 is in a low position, the flow state of the diverter 5 in the feed port 11 located on the left side of the diverter plate 4 is closed, and the flow state of the diverter 5 in the feed port 11 located on the right side of the diverter plate 4 is open, while the movable plug 54 in the discharge port 12 is in a high position, the flow state of the diverter 5 in the discharge port 12 located on the left side of the diverter plate 4 is open, and the flow state of the diverter 5 in the discharge port 12 located on the right side of the diverter plate 4 is closed; In this state, the material flowing into the feed port 11 enters through the right side of the diverter plate 4, and flows up and down in the right material guide channel to the other end in a wave-like manner, and enters the left material guide channel through the notch 41 of the diverter plate 4, and flows up and down in a wave-like manner to the initial end again, and then flows out from the discharge port 12; Within a certain period of time, the driving assembly 55 drives the movable plug 54 to change its position to Figure 7 As shown, the movable plug 54 in the feed port 11 is in a high position, the flow state of the diverter 5 in the feed port 11 located on the left side of the diverter plate 4 is open, and the flow state of the diverter 5 in the feed port 11 located on the right side of the diverter plate 4 is closed, while the movable plug 54 in the discharge port 12 is in a low position, the flow state of the diverter 5 in the discharge port 12 located on the left side of the diverter plate 4 is closed, and the flow state of the diverter 5 in the discharge port 12 located on the right side of the diverter plate 4 is open; In this state, the material flowing into the feed port 11 enters through the left side of the diverter plate 4, and flows up and down in the left material guide channel to the other end in a wave-like manner, and enters the right material guide channel through the notch 41 of the diverter plate 4, and flows up and down in a wave-like manner to the initial end again, and then flows out from the discharge port 12; The present invention controls the height of the movable plugs 54 in the feed port 11 and the discharge port 12 to achieve switching of the flow direction of the material guide channel by the diverter 5, so that the material can move in a circuitous manner in the two material guide channels along different sides, thereby reducing the temperature difference of the material in the material guide channels on both sides and improving the cooling effect on the material.

[0028] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An energy-saving heat exchange device for a nitrate microchannel reactor, comprising a microchannel reactor for carrying out a nitrate mixing reaction on materials, a primary shell and tube heat exchanger and a secondary shell and tube heat exchanger for sequentially cooling the materials after the reaction, characterized in that: The first-stage shell and tube heat exchanger and the second-stage shell and tube heat exchanger both comprise a shell (1), one end of the shell (1) being provided with an inlet (11) and an outlet (12) distributed vertically, a row of upper menisci (2) and a row of lower menisci (3) distributed vertically with the upper menisci (2) being fixed inside the shell (1), and the upper menisci (2) and the lower menisci (3) being arranged alternately along the length direction of the shell (1), a heat exchange component for cooling the material flowing through being arranged on the upper menisci (2), and a water inlet (13) and a water outlet communicating with the end of the heat exchange component being arranged on both sides of the upper meniscus (2). (14), the upper meniscus (2) and the lower meniscus (3) separate the shell (1) to form a material guide area that enables the material to advance in a wave-like manner in the shell (1), a flow divider (4) vertically distributed with the upper meniscus (2) and the lower meniscus (3) is fixed in the shell (1), and a notch (41) is provided at the bottom of one end of the flow divider (4) away from the feed port (11) and the discharge port (12), the flow divider (4) separates the material guide area to form two circuitous material guide channels, and the feed port (11) and the discharge port (12) are both provided with a flow divider (5) that can switch the flow direction of the material in the two material guide channels.

2. The energy-saving heat exchange device for a nitrate microchannel reactor according to claim 1, characterized in that: The heat exchange assembly comprises a plurality of heat exchange tubes (6) distributed in an array on the upper meniscus (2); the upper meniscus (2) located at both ends of the heat exchange tubes (6) are hollow structures and have circular holes (21) on the sides thereof which are respectively connected to the water inlet (13) and the water outlet (14); the heat exchange tubes (6) are connected to the inner cavities of the upper meniscus (2) at both ends.

3. The energy-saving heat exchange device for a nitrate microchannel reactor according to claim 1 is characterized in that: The flow divider (5) comprises an outer tube body (51), the outer tube body (51) being fixed to the outside of the housing (1), a partition plate (53) being fixed inside the outer tube body (51), the upper end of the partition plate (53) being fixedly connected to the flow divider plate (4), an inner tube body (52) being fixed on the partition plate (53), the partition plate (53) separating the outer tube body (51) and the inner tube body (52) into two material guide channels, respectively, and a movable plug (54) and a driving component (55) for driving the movable plug (54) to slide up and down so as to guide the material to different material guide cavities are arranged inside the inner tube body (52).

4. The energy-saving heat exchange device for a nitrate microchannel reactor according to claim 3 is characterized in that: A stop ring (521) and a sealing ring (522) located below the stop ring (521) are fixed inside the inner tube body (52); a first flow opening (523) located between the stop ring (521) and the sealing ring (522) is provided on the inner tube body (52); a second flow opening (524) located below the sealing ring (522) is provided on the inner tube body (52); the first flow opening (523) and the second flow opening (524) lead to two material guide chambers respectively.

5. The energy-saving heat exchange device for a nitrate microchannel reactor according to claim 4 is characterized in that: The movable plug (54) comprises an upper cone (541), a cylinder (542) and a lower cone (543) which are integrally formed from top to bottom; the cylinder (542) and the lower cone (543) are hollow inside; a plurality of guide holes (544) distributed in an annular pattern are formed on the cylinder (542); a conduit (545) is fixed to the bottom of the lower cone (543); and a flow guide cover (546) is fixed to the bottom of the conduit (545).

6. The energy-saving heat exchange device for a nitrate microchannel reactor according to claim 5, characterized in that: The diameter of the upper cone (541) gradually decreases from top to bottom and fits in place with the inner wall of the inner tube (52); the diameter of the lower cone (543) gradually increases from top to bottom and fits in place with the inner wall of the inner tube (52); the diameter of the cylinder (542) is equal to the bottom diameter of the upper cone (541) and the top diameter of the lower cone (543).

7. The energy-saving heat exchange device for a nitrate microchannel reactor according to claim 5, characterized in that: The diameter of the flow guide cover (546) gradually increases from top to bottom and fits closely to the inner wall of the outer tube body (51).

8. The energy-saving heat exchange device for a nitrate microchannel reactor according to claim 5, characterized in that: The driving assembly (55) comprises a first electromagnet (551), a spring (552) and a second electromagnet (553); the first electromagnet (551) is fixed to the inner bottom wall of the inner tube (52); the second electromagnet (553) is fixed to the bottom wall of the lower cone (543); the spring (552) is sleeved outside the guide tube (545); and two ends of the spring (552) are respectively fixed to the first electromagnet (551) and the second electromagnet (553).

Images