A heat withdrawal water pipe, fluidized bed reactor and application thereof in acrylonitrile manufacturing

Abstract

A heat removal tube bundle for removing heat from a reactor or providing heat to the reactor, characterized in that it comprises at least one first heat removal tube comprising a first inlet main tube passing through a reactor wall of the reactor from outside the reactor into the interior of the reactor and at least two first branch tubes in fluid communication with the first inlet main tube, any one of the first branch tubes comprising at least two adjacent straight tubes and a connecting piece for connecting the at least two straight tubes in series and in fluid communication, wherein the average of the cross-sectional areas of all the straight tubes in any one of the first branch tubes in a cross-section perpendicular to the respective longitudinal axis of the straight tubes is the cross-sectional area of the first branch tube, and the ratio of the cross-sectional area of the first inlet main tube perpendicular to the longitudinal axis of the first inlet main tube to the sum of the cross-sectional areas of all the first branch tubes is 0.5 to 1.

Description

TECHNICAL FIELD

[0001] The present invention relates to a fluidized bed reactor and a heat removal water pipe, which is particularly suitable for being arranged in the fluidized bed reactor. The present invention further relates to the use of the fluidized bed reactor and the heat removal water pipe in acrylonitrile production. BACKGROUND

[0002] Acrylonitrile is an important chemical raw material in petrochemical industry. The one-step method of propylene ammoxidation is widely used in the world to produce acrylonitrile, i.e. under the action of fluidized bed ammoxidation catalyst, propylene ammoxidation generates acrylonitrile, while by-products such as acetonitrile, hydrocyanic acid, etc. are also produced, and CO, CO2 deep oxidation products are also generated. The reaction is a strong exothermic reaction, and a large amount of heat is generated during the reaction process.

[0003] Typical internal components of acrylonitrile fluidized bed reactor include propylene ammonia distributor, air distribution plate, heat removal water pipe (also known as cooling coil) and cyclone separator, wherein the legs of the heat removal water pipe and the cyclone separator serve as vertical components of the fluidized bed in the catalyst bed. The heat removal water pipe can timely remove a large amount of generated reaction heat from the reaction system and maintain the reaction temperature in a stable state, while the cyclone separator captures the catalyst entrained when the gas moves upward and returns the catalyst to the catalyst bed through the leg to reduce the loss of catalyst.

[0004] Figure 1 An acrylonitrile fluidized bed reactor is shown, which mainly includes: oxygen-containing gas distribution plate, propylene ammonia distributor, heat removal pipe, cyclone separator. In the prior art acrylonitrile reactor as shown in Figure 1 In the prior art acrylonitrile reactor as shown in SUMMARY

[0005] In existing acrylonitrile fluidized bed reactors, the number of heat-removing tubes in an empty state is relatively small, and the number of heat-removing tubes that can switch between operating and empty states is very limited. As the operating cycle of the device extends, more Mo scale adheres to the surface of the heat-removing tubes, reducing heat transfer efficiency, requiring more heat-removing tubes to be in operating state to maintain stable reaction temperature. On the other hand, when a large number of heat-removing tubes are installed, there are concerns about affecting the reactor wall strength because openings need to be added to the reactor wall for the pipelines supplying the heat-removing medium to the tubes. Furthermore, when using a fluidized bed reactor for the ammoxidation of propylene to produce acrylonitrile, the ammoxidation reaction is a gas-solid heterogeneous catalytic reaction. The gas flow pattern within the reactor differs from that in a free bubbling bed; the bubbles generated by the gas passing through the distribution plate increase in size as the bed height increases. The inventors of this invention have discovered that the presence of vertical internal components helps to break up bubbles; smaller bubbles are more conducive to mass transfer than larger bubbles, improving the formation of effective products. The inventors of this invention further discovered that, in addition to its basic function, the hot water cooling pipe, as a vertical component, also plays a role in breaking up bubbles and helps reduce the degree of backmixing of the gas and solid phases, thus reducing the formation of deep oxidation products. The distribution of these vertical components on the reactor cross-section directly affects whether bubble enlargement or bubble breaking can be effectively limited, thereby directly influencing the reaction results. On the other hand, as the capacity of the acrylonitrile fluidized bed reactor increases, the number of hot water cooling pipes in the cooling section of the reactor also increases. Since the cooling medium needs to be supplied to the hot water cooling pipes through the reactor wall, the number of openings on the reactor wall also increases accordingly. However, too many openings or excessively large opening areas will lead to a decrease in the strength of the reactor wall. This invention is based on this discovery.

[0006] Specifically, the present invention relates to the following aspects:

[0007] 1. A heat removal tube assembly for removing heat from or supplying heat to a reactor, comprising at least one first heat removal tube, the first heat removal tube comprising:

[0008] A first inlet pipe, which enters the reactor from the outside of the reactor through the reactor wall; and

[0009] At least two first branch pipes are in fluid communication with the first inlet main pipe. Each first branch pipe includes at least two adjacent (preferably parallel to the longitudinal axis of the reactor) straight pipes and a connecting fitting for connecting the at least two straight pipes in series and in fluid communication.

[0010] wherein the ratio of the cross-sectional area of the second inlet main pipe perpendicular to the longitudinal axis of the second inlet main pipe to the cross-sectional area of the second branch pipe is 1.0 to 1.7, preferably 1.05 to 1.4, more preferably 1.1 to 1.25.

[0011] 2. The heat removal tube set of any of the preceding or subsequent claims,

[0012] the number of the first branch pipes is 2 to 8, preferably 2 to 6, more preferably 2 to 4, and / or

[0013] any of the first branch pipes comprises 2 to 20 straight pipes, preferably 2 to 16, more preferably 2 to 12.

[0014] 3. The heat removal tube set of any of the preceding or subsequent claims,

[0015] the total number of the straight pipes in all the first branch pipes is 4 to 160, preferably 4 to 140, more preferably 4 to 120.

[0016] 4. The heat removal tube set of any of the preceding or subsequent claims, further comprising at least one second heat removal tube, which comprises:

[0017] a second inlet main pipe which enters the interior of the reactor from the exterior of the reactor through a reactor wall of the reactor; and

[0018] one second branch pipe in fluid communication with the second inlet main pipe, the second branch pipe comprising at least two adjacent (preferably parallel to the longitudinal axis of the reactor) straight pipes and a connecting pipe piece for connecting the at least two straight pipes in series and in fluid communication,

[0019] wherein the ratio of the cross-sectional area of the second inlet main pipe perpendicular to the longitudinal axis of the second inlet main pipe to the cross-sectional area of the second branch pipe is 1.0 to 1.7, preferably 1.05 to 1.4, more preferably 1.1 to 1.25.

[0020] 5. The heat removal tube set of any of the preceding or subsequent claims,

[0021] the second branch pipe comprises 2 to 20 straight pipes, preferably 2 to 16, more preferably 2 to 12.

[0022] 6. The heat withdrawal tube bundle of any of the preceding or following claims, the number of first legs being 66% or less, preferably 50% or less, and more preferably 33% or less, of the total number of first legs and second legs.

[0023] 7. The heat withdrawal tube bundle of any of the preceding or following claims, comprising at least one third heat withdrawal tube, the third heat withdrawal tube comprising:

[0024] a first outlet main tube passing from inside the reactor through a reactor wall of the reactor to outside the reactor, and

[0025] at least two third legs in fluid communication with the first outlet main tube, any of the third legs comprising at least two adjacent (preferably parallel to the longitudinal axis of the reactor) straight tubes and a connecting piece for connecting the at least two straight tubes in series and in fluid communication,

[0026] wherein the ratio of the cross-sectional area of the first outlet main tube perpendicular to the longitudinal axis of the first outlet main tube to the sum of the cross-sectional areas of all third legs is 0.5 to 1, preferably 0.55 to 0.95, and more preferably 0.6 to 0.9, provided that the average of the cross-sectional areas of all straight tubes in any of the third legs, in a cross-section perpendicular to the respective longitudinal axis, is the cross-sectional area of the third leg.

[0027] 8. The heat withdrawal tube bundle of any of the preceding or following claims,

[0028] the number of third legs being 2 to 8, preferably 2 to 6, and more preferably 2 to 4, and / or

[0029] any of the third legs comprising 2 to 20 straight tubes, preferably 2 to 16, and more preferably 2 to 12.

[0030] 9. The heat withdrawal tube bundle of any of the preceding or following claims,

[0031] the total number of straight tubes in all third legs being 4 to 160, preferably 4 to 140, and more preferably 4 to 120.

[0032] 10. The heat withdrawal tube bundle of any of the preceding or following claims, further comprising at least one fourth heat withdrawal tube, the fourth heat withdrawal tube comprising:

[0033] a second outlet main tube passing from inside the reactor through a reactor wall of the reactor to outside the reactor; and

[0034] 1. a fourth manifold in fluid communication with said second outlet main pipe, said fourth manifold comprising at least two adjacent (preferably parallel to the longitudinal axis of said reactor) straight pipes and connecting pieces for connecting said at least two straight pipes in series and in fluid communication,

[0035] wherein the average of the cross-sectional areas of all the straight pipes in said fourth manifold, taken in a cross-section perpendicular to the respective longitudinal axis, is the cross-sectional area of said fourth manifold, and the ratio of the cross-sectional area of said second outlet main pipe, taken in a cross-section perpendicular to the longitudinal axis of said second outlet main pipe, to the cross-sectional area of said fourth manifold is 1.0-1.7, preferably 1.05-1.4, more preferably 1.10-1.25.

[0036] 11. The heat removal tube bundle of any of the preceding or following claims,

[0037] Said fourth manifold comprises 2-20 of said straight pipes, preferably 2-16, more preferably 2-12.

[0038] 12. The heat removal tube bundle of any of the preceding or following claims, the number of said third manifolds in fluid communication with said first outlet main pipe is 66% or less, preferably 50% or less, more preferably 33% or less, of the total number of said third manifolds and said fourth manifolds.

[0039] 13. The heat removal tube bundle of any of the preceding or following claims, the outer diameter of each straight pipe of at least one of said first manifold, said second manifold, said third manifold and said fourth manifold is independently 80-180 mm, preferably 90-170 mm, and / or the inner diameter of each straight pipe is independently 60-150 mm, preferably 70-140 mm, and / or the length of each straight pipe is independently 4.0-13 m, preferably 5.5-12.0 m, and / or the outer diameter of said first inlet main pipe and said first outlet main pipe is independently 100-270 mm, preferably 110-250 mm, and / or the inner diameter of said first inlet main pipe and said first outlet main pipe is independently 80-250 mm, preferably 90-230 mm, and / or the outer diameter of said second inlet main pipe and said second outlet main pipe is independently 100-270 mm, preferably 110-250 mm, and / or the inner diameter of said second inlet main pipe and said second outlet main pipe is independently 80-250 mm, preferably 90-230 mm.

[0040] 14. A heat removal tube bundle for removing heat from a reactor or providing heat to said reactor, comprising:

[0041] at least 1 first inlet main pipe, which first inlet main pipe penetrates a reactor wall of said reactor into the interior of the reactor,

[0042] at least one first outlet main pipe passing through a reactor wall of the reactor into the interior of the reactor, and

[0043] at least two branch pipes, any one of the branch pipes comprising at least two adjacent straight pipes parallel to the longitudinal axis of the reactor and a connecting pipe piece for connecting the at least two straight pipes in series and in fluid communication, wherein

[0044] any one of the first inlet main pipes is in fluid communication with more than two branch pipes, and

[0045] any one of the first outlet main pipes is in fluid communication with more than two branch pipes,

[0046] wherein, if the average of the cross-sectional areas of all the straight pipes in any one of the branch pipes in fluid communication with the first inlet main pipe is the cross-sectional area of the branch pipe, the ratio of the cross-sectional area of the first inlet main pipe perpendicular to the longitudinal axis of the first inlet main pipe to the sum of the cross-sectional areas of all the branch pipes in fluid communication with the first inlet main pipe is 0.5 to 1, preferably 0.55 to 0.95, more preferably 0.6 to 0.9, and

[0047] wherein, if the average of the cross-sectional areas of all the straight pipes in any one of the branch pipes in fluid communication with the first outlet main pipe is the cross-sectional area of the branch pipe, the ratio of the cross-sectional area of the first outlet main pipe perpendicular to the longitudinal axis of the first outlet main pipe to the sum of the cross-sectional areas of all the branch pipes in fluid communication with the first outlet main pipe is 0.5 to 1, preferably 0.55 to 0.95, more preferably 0.6 to 0.9.

[0048] 15. The heat withdrawal tube bundle of any of the preceding or following claims,

[0049] the number of the branch pipes is 2 to 8, preferably 2 to 6, more preferably 2 to 4, and / or

[0050] any one of the branch pipes comprises 2 to 20 straight pipes, preferably 2 to 16, more preferably 2 to 12.

[0051] 16. The heat withdrawal tube bundle of any of the preceding or following claims,

[0052] the total number of the straight pipes in all the branch pipes is 4 to 160, preferably 4 to 140, more preferably 4 to 120.

[0053] 17. The heat withdrawal tube bundle of claim 14, further comprising:

[0054] at least one second inlet main pipe, and

[0055] at least one second outlet main pipe, wherein

[0056] any one of the second inlet headers is in fluid communication with one of the legs, and

[0057] any one of the second outlet headers is in fluid communication with one of the legs,

[0058] wherein the ratio of the cross-sectional area of any one of the second inlet headers perpendicular to the longitudinal axis of the second inlet header to the average cross-sectional area of all of the straight sections of the legs in fluid communication with the second inlet header is in the range of 1.0 to 1.7, preferably in the range of 1.05 to 1.4, and more preferably in the range of 1.10 to 1.25, and

[0059] wherein the ratio of the cross-sectional area of any one of the second outlet headers perpendicular to the longitudinal axis of the second outlet header to the average cross-sectional area of all of the straight sections of the legs in fluid communication with the second outlet header is in the range of 1.0 to 1.7, preferably in the range of 1.05 to 1.4, and more preferably in the range of 1.10 to 1.25.

[0060] 18. The heat withdrawal tube panel of any preceding or subsequent item, the number of legs in fluid communication with the first outlet headers is 66% or less, preferably 50% or less, and more preferably 33% or less, of the total number of legs.

[0061] 19. The heat withdrawal tube panel of any preceding or subsequent item, the outer diameter of each straight section of the legs is independently in the range of 80 to 180 mm, preferably in the range of 90 to 170 mm, and / or the inner diameter of each straight section of the legs is independently in the range of 60 to 150 mm, preferably in the range of 70 to 140 mm, and / or the length of each straight section of the legs is independently in the range of 4.0 to 13 m, preferably in the range of 5.5 to 12.0 m, and / or the outer diameter of the first inlet headers and the first outlet headers is independently in the range of 100 to 270 mm, preferably in the range of 110 to 250 mm, and / or the inner diameter of the first inlet headers and the first outlet headers is independently in the range of 80 to 250 mm, preferably in the range of 90 to 230 mm, and / or the outer diameter of the second inlet headers and the second outlet headers is independently in the range of 100 to 270 mm, preferably in the range of 110 to 250 mm, and / or the inner diameter of the second inlet headers and the second outlet headers is independently in the range of 80 to 250 mm, preferably in the range of 90 to 230 mm.

[0062] 20. A reactor comprising the heat withdrawal tube panel of any preceding or subsequent item, and any one of the first inlet headers, the second inlet headers, the first outlet headers and the second outlet headers penetrates the wall of the reactor and is airtightly connected to the wall by a connection.

[0063] 21. A method of heat removal from a reactor using the heat removal tube bundle of any of the preceding or subsequent claims to recover heat generated by a reaction in the reactor, or to provide heat required for a reaction in the reactor using the heat removal tube bundle of any of claims 1 to 11.

[0064] 22. Use of the heat removal tube bundle of any of the preceding or subsequent claims in a fluidized bed reactor for the production of an epoxide compound (such as propylene oxide) from an oxidation process of an olefin (such as propylene) or an unsaturated nitrile (such as acrylonitrile) from an ammoxidation process.

[0065] 23. A method of producing an unsaturated nitrile comprising the step of subjecting an olefin (such as propylene) to an ammoxidation reaction to produce an unsaturated nitrile (such as acrylonitrile) in a fluidized bed reactor comprising the heat removal tube bundle of any of the preceding or subsequent claims. BRIEF DESCRIPTION OF DRAWINGS

[0066] Figure 1 is a front view schematic of a prior art fluidized bed reactor.

[0067] Figure 2 is a top view schematic of a prior art fluidized bed reactor heat removal tube bundle.

[0068] Figure 3 is a front view schematic of a fluidized bed reactor heat removal tube bundle of the present invention.

[0069] Figures 4A-4C is a schematic of the arrangement of heat removal tubes of the heat removal tube bundle of the present invention.

[0070] Figure 5 is a schematic of the heat removal tube bundle of the present invention.

[0071] Figure 6 is a schematic of the heat removal tube bundle of the present invention.

[0072] Figure 7A and 7B is a schematic of the heat removal tube bundle of the present invention.

[0073] Figure 8A and 8B is a schematic of the heat removal tube bundle of the present invention.

[0074] REFERENCE NUMERALS:

[0075] 1 : fluidized bed reactor wall

[0076] 2, 10, 20: heat removal tube of the fluidized bed reactor

[0077] 3: heat removal tube inlet of the fluidized bed reactor

[0078] 4: heat removal tube outlet of the fluidized bed reactor

[0079] 5: lower connecting pipe fitting of heat removal pipe

[0080] 6: upper connecting pipe fitting of heat removal pipe

[0081] 7: oxygen-containing gas distribution plate

[0082] 8: propylene ammonia distributor

[0083] 9: high-efficiency cyclone separator

[0084] Technical effects

[0085] According to the heat removal pipe group and the fluidized bed reactor of the present application, the production capacity of the device target product can be improved, and the device operation cost can be reduced.

[0086] According to the heat removal pipe group and the fluidized bed reactor of the present application, the change of the flow pattern in the fluidized bed can be accelerated, and the mass transfer efficiency can be improved.

[0087] According to the heat removal pipe group and the fluidized bed reactor of the present application, in the case of increasing the number of heat removal pipes, the number and total opening area of openings on the reactor wall can be reduced, thereby avoiding the reduction of the reactor wall strength.

[0088] According to the heat removal pipe group and the fluidized bed reactor of the present application, the reactor temperature can be sensitively and accurately controlled.

[0089] According to the heat removal pipe group and the fluidized bed reactor of the present application, the growth of gas bubbles can be effectively inhibited, so as to improve the raw material gas conversion rate and increase the yield of the target reaction product.

[0090] According to the heat removal pipe group and the fluidized bed reactor of the present application, the backmixing degree of gas-solid phase can be reduced, and the generation of deep oxidation products can be reduced.

[0091] According to the heat removal pipe group and the fluidized bed reactor of the present application, the heat transfer efficiency can be improved, and the device operation cycle can be prolonged.

[0092] According to the heat removal pipe group and the fluidized bed reactor of the present application, more straight pipes can be arranged in the unit cross-sectional area of the heat removal section of the fluidized bed reactor, so as to enhance the heat removal capacity. DETAILED DESCRIPTION

[0093] The specific embodiments of the present application are described in detail below, but it should be pointed out that the protection scope of the present application is not limited by these specific embodiments, but is determined by the claims in the appendix.

[0094] All publications, patent applications, patents, and other references mentioned in this specification are herein incorporated by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as is commonly understood by one of ordinary skill in the art. In case of conflict between the definitions in this specification and that of any document incorporated herein by reference, the definition in this specification prevails.

[0095] When the specification uses phrases such as "known to those skilled in the art", "prior art", or their equivalents, the objects of the phrases encompass those which are conventionally used at the time of filing this application, but also include those which are not yet conventionally used, but will be recognized as being suitable for similar purposes in the art.

[0096] In the context of this specification, the term "substantially" means that a deviation which is acceptable or considered reasonable by those skilled in the art is allowed, such as a deviation within ±10%, within ±5%, within ±1%, within ±0.5%, or within ±0.1%.

[0097] All percentages, parts, ratios, etc. mentioned in this specification are based on weight, unless explicitly indicated otherwise, and pressures are gauge pressures.

[0098] The "heat-removal tube set" and "heat-removal tube" of the present application can be used to remove excess heat from a reactor in which an exothermic reaction (or some exothermic phase of a reaction) is carried out, so that the reaction is maintained within a certain temperature range. However, the "heat-removal tube set" and "heat-removal tube" of the present application can also be used to supply heat to a reactor in which an endothermic reaction (or some endothermic phase of a reaction) is carried out, so that the reaction is maintained within a certain temperature range.

[0099] In the context of this specification, any two or more embodiments of the present application can be combined arbitrarily, and the technical solutions thus formed are part of the original disclosure of this specification, and also fall within the scope of protection of the present application.

[0100] According to one embodiment of the present application, a fluidized bed reactor, in particular a fluidized bed reactor for acrylonitrile production, is provided. Here, the fluidized bed reactor comprises at least a reaction heat-removal section and a heat-removal tube set arranged in the reaction heat-removal section.

[0101] According to one embodiment of the present application, the straight tubes of the heat-removal tube set are located substantially in the dense phase zone of the fluidized bed reactor, for timely removal of reaction heat from the system and maintenance of stable operation of the system. For this purpose, in the context of this specification, the term "heat-removal section" refers to the region of the fluidized bed reactor in which the heat-removal tube set is arranged, more particularly to the region in which the straight tubes of the heat-removal tube set are located in the fluidized bed reactor, and more particularly to the region in which the straight tubes of the heat-removal tube set are arranged in the dense phase zone of the fluidized bed reactor.

[0102] Ideally, the heat removal tube assembly within the heat removal section can be arranged according to... Figure 2 The arrangement shown depicts the heat dissipation tubes arranged in a straight line. However, to further improve fluidization and meet the demands of high production capacity, the existing heat dissipation tube assemblies may not be sufficient for normal plant operation. Furthermore, as... Figure 1 As shown, the cooling section of the fluidized bed reactor also includes other internal components such as the feed leg of the cyclone separator 9. This invention solves this technical problem by making the two connecting pipes in the same cooling pipe form an angle.

[0103] Specifically, according to one embodiment of the present invention, a heat removal tube assembly is disposed within the heat removal section of a fluidized bed reactor, the heat removal section being disposed within the fluidized bed layer of the fluidized bed reactor, and the heat removal tube assembly comprising heat removal tubes 2. For example... Figure 3 As shown, each of the heat dissipation pipes 2 includes: an inlet 3, an outlet 4, at least three adjacent straight pipes, and a connecting fitting for connecting any two adjacent straight pipes in series and allowing fluid communication. Figures 4A-4C In section 5, when the connecting fitting connecting any two straight pipes is located below the straight pipe (hereinafter sometimes referred to as "lower connecting fitting 5"), the other adjacent connecting fitting is located above the straight pipe (hereinafter sometimes referred to as "lower connecting fitting 6").

[0104] According to one embodiment of the present invention, the heat dissipation pipe assembly includes at least one, preferably 10 to 100, more preferably 20 to 80 heat dissipation pipes, wherein the heat dissipation pipe includes N (N is greater than or equal to 3, preferably N is 3 to 30, more preferably N is 3 to 20) straight pipes and N-1 connecting pipe fittings for connecting any two adjacent straight pipes in series and fluidly communicating with each other.

[0105] On the other hand, such as Figure 3 As shown, let the length of the heat removal section along the central axis of the fluidized bed reactor be L (in meters). Then, within the entire length L of the heat removal section, preferably within a region of 49%L above and below the center point of the heat removal section, more preferably within a region of 45%L above and 38%L below the center point of the heat removal section, and even more preferably within a region of 40%L above and 8%L below the center point of the heat removal section, when transversely cut along a direction perpendicular to the central axis of the fluidized bed reactor at any position, let the area of ​​the transverse section of the heat removal section be S1 (in meters). 2 If the cross-section of the heat dissipation section contains all the straight pipes of the heat dissipation tube group, then the outer perimeter of the cross-section is L1 (in meters), and L1 / S1 is 1.0-6.0m. -1 Preferably, it is 2.0-4.0m -1 More preferably, it is 2.5-3.5m-1 .

[0106] like Figure 3 As shown, according to one embodiment of the present invention, in at least one of the heat-relieving pipes, the angle between the extension line of the central axis of the projection of at least one connecting pipe on the cross section and the extension line of the central axis of the projection of at least one other connecting pipe on the cross section is greater than 0° and less than 180°, preferably 30° to 150°, more preferably 60° to 120°, and even more preferably 90°.

[0107] Specifically, in the projection on the cross-section, the straight pipes and connecting fittings in the same heat dissipation pipe 2 can be arranged according to... Figures 4A-4C Arrange the items as shown.

[0108] According to one embodiment of the present invention, the cross-sectional outer contour of the straight tube of the heat-relieving tube 2 in the heat-relieving tube assembly is substantially circular, with an outer contour circumference L = 3.14 × D. Here, D is the diameter of the outer contour of the straight tube (in meters). Therefore, in such... Figure 5 In the cross section of the heat removal section shown, the sum of the outer perimeters of the cross sections of all the straight pipes in the heat removal tube group, L1, is the sum of the outer perimeters of all the straight pipes in the cross section of the heat removal section.

[0109] According to one embodiment of the present invention, if the total number of straight pipes in the heat dissipation pipe group within the cross-section is N, then the number of straight pipes per unit area of ​​the cross-section, N / S1, is 4-16 pipes / m. 2 Preferably 5-12 per m 2 More preferably 6-11 per m 2 .

[0110] According to one embodiment of the present invention, the cross-section of the heat removal section of the acrylonitrile fluidized bed reactor is circular, elliptical, or oval, preferably circular. Furthermore, the area of ​​the cross-section is 20-700 m². 2 Preferably 35-350m 2 .

[0111] According to one embodiment of the present invention, the length L of the heat removal section is 4-13m, preferably 5-12m.

[0112] According to one embodiment of the present invention, the outer diameters of the straight pipes in the heat dissipation pipe assembly may be the same or different. Specifically, the outer diameter of each straight pipe in the heat dissipation pipe assembly is independently 80-180 mm, preferably 90-170 mm, and / or the inner diameter of each straight pipe is independently 60-150 mm, preferably 70-140 mm, and / or the length of each straight pipe is independently 4-13 m, preferably 5-12 m.

[0113] According to one embodiment of the present application, the heat removal tube group and the fluidized bed reactor using the heat removal tube group of the present application can be applied to other fluidized bed reactions besides the reaction of preparing acrylonitrile from propylene by ammoxidation, such as preparing acrylonitrile from propane by ammoxidation, etc. According to one embodiment of the present application, the heat removal tube group can recover saturated steam of 1-10 MPa, preferably saturated steam of 2-8 MPa, and more preferably saturated steam of 3-5 MPa from the fluidized bed reactor, depending on the specific reaction.

[0114] According to one embodiment of the present application, the heat removal tube group enables the heat removal section of the fluidized bed reactor to recover the heat of 4.5 MPa saturated steam of 0.5-3.0 t per hour, preferably 1.0-2.5 t per hour, and more preferably 1.5-2.0 t per hour per unit cross-sectional area (m2) of the cross section transverse to the flow direction of the fluidized bed reactor. 2 ) per hour.

[0115] According to one aspect of the present application, the heat removal tube group can remove the heat of 15-60 t of steam per hour from the fluidized bed reactor with a diameter of not more than 5 meters, preferably 20-40 t of steam per hour.

[0116] According to one aspect of the present application, the heat removal tube group can remove the heat of 20-100 t of steam per hour from the fluidized bed reactor with a diameter of not more than 7 meters, preferably 40-80 t of steam per hour.

[0117] According to one aspect of the present application, the heat removal tube group can remove the heat of 60-200 t of steam per hour from the fluidized bed reactor with a diameter of not more than 10 meters, preferably 90-160 t of steam per hour.

[0118] According to one aspect of the present application, the heat removal tube group can remove the heat of 60-300 t of steam per hour from the fluidized bed reactor with a diameter of not more than 12 meters, preferably 140-250 t of steam per hour.

[0119] According to one aspect of the present application, the heat removal tube group can remove the heat of 100-500 t of steam per hour from the fluidized bed reactor with a diameter of not more than 15 meters, preferably 200-400 t of steam per hour.

[0120] According to one embodiment of the present application, the radius of the circular cross section of the heat removal section of the fluidized bed reactor is R, and the central region of the cross section refers to the range within a certain distance from the center of the circular cross section (i.e. Figure 6 ​Figure 6 the center region of the cross section refers to a circular region within 3 / 4R from the center of the cross section, preferably a circular region within 2 / 3R from the center of the cross section, more preferably a circular region within 1 / 2R from the center of the cross section, still more preferably a circular region within 1 / 3R from the center of the cross section. Figure 6

[0121] According to one embodiment of the present application, the heat extraction tube set comprises at least one first heat extraction tube 10 comprising n1 adjacent straight tubes a perpendicular to the cross section (parallel to the central axis direction of the fluidized bed reactor) and n1-1 connecting tube pieces for connecting the n1 straight tubes in series and in fluid communication, wherein 2 < n1 < 30, preferably 2 < n1 < 20, more preferably 2 < n1 < 10, and at least one second heat extraction tube 20 comprising n2 adjacent straight tubes b perpendicular to the cross section (parallel to the central axis direction of the fluidized bed reactor) and n2-1 connecting tube pieces for connecting the n2 straight tubes in series and in fluid communication, wherein 2 < n2 < 30, preferably 2 < n2 < 20, more preferably 2 < n2 < 10. More than 50% (preferably more than 60%, more preferably 70%) of the number of straight tubes of the first heat extraction tube 10 is within the center region of the cross section of the heat extraction section of the fluidized bed reactor, while less than 50% (preferably less than 40%, more preferably less than 30%) of the number of straight tubes of the second heat extraction tube 20 is within the center region of the cross section. For example, when the first heat extraction tube 10 has 8 straight tubes, more than 5 straight tubes are within the center region of the cross section, or when the first heat extraction tube 10 has 7 straight tubes, more than 4 straight tubes are within the center region of the cross section. On the other hand, when the second heat extraction tube 20 has 6 straight tubes, less than 2 straight tubes are within the center region of the cross section, or when the second heat extraction tube 20 has 5 straight tubes, less than 2 straight tubes are within the center region of the cross section.

[0122] In one embodiment of the present application, the ratio between the sum of the outer contour perimeters of all straight tubes of the first heat extraction tube 10 and the sum of the outer contour perimeters of all straight tubes of the second heat extraction tube 20 is greater than 1 and less than or equal to 2, more preferably greater than 1 and less than or equal to 1.5, still more preferably greater than 1 and less than or equal to 1.1.

[0123] In one embodiment of the present application, the number n1 of straight tubes a of the first heat extraction tube 10 and the number n2 of straight tubes b of the second heat extraction tube 20 satisfy the following relationship:

[0124] ​n1-n2<5, and preferably, n1-n2<3.

[0125] In one embodiment of the present application, the ratio of the outer diameter of the straight tube a to the outer diameter of the straight tube b is 1-1.8, preferably 1-1.5.

[0126] The heat removal tube set of the above-mentioned embodiment of the present application can adjust the reactor temperature in the range of 0.1-2°C.

[0127] The heat removal tube set of the above-mentioned embodiment of the present application can adjust the reactor temperature in the range of 0.5-1°C.

[0128] As shown in Figure 7A and 7B The heat removal tube set of one embodiment of the present application comprises at least one first heat removal tube 11, which comprises a first inlet main tube 111 and at least 2 (2 in Figure 7A 3 in Figure 7B 4 in) first branch tubes 112, which are respectively in fluid communication with the first inlet main tube 111. The first inlet main tube 111 penetrates the reactor wall 1 to supply the heat removal medium to each first branch tube 112. Any one of the first branch tubes 112 comprises at least 2 adjacent (preferably parallel to the longitudinal axis of the reactor) straight tubes and a connecting pipe for connecting the at least two straight tubes in series and in fluid communication.

[0129] In one embodiment of the present application, the number of the first branch tubes 112 in fluid communication with the first inlet main tube 111 is 2-8, preferably 2-6, and more preferably 2-4. When the number of the first branch tubes 112 in fluid communication with one first inlet main tube 111 exceeds 8, in order to supply sufficient heat removal medium to all the first branch tubes 112, the first inlet main tube 111 needs to have an excessively large tube diameter (cross-sectional area), and in order to make such a first inlet main tube 111 penetrate the reactor wall, the opening on the reactor wall needs to be correspondingly increased, which in turn leads to the decrease of the strength of the reactor wall or the increase of the manufacturing cost.

[0130] The number of the straight tubes constituting any one of the first branch tubes 112 is not particularly limited, and is usually 2-20, preferably 2-10, and more preferably 2-6. The number of the straight tubes constituting all the first branch tubes 112 in the first heat removal tube 11 is not particularly limited, but is usually 4-160, preferably 4-140, and more preferably 4-120. When the number of the straight tubes is more than the above-mentioned range, the evaporation rate of the heat removal medium in the first heat removal tube will decrease, which in turn affects the heat removal effect.

[0131] In one embodiment of the present application, the cross-sectional area of the first inlet main tube 111 perpendicular to its own longitudinal axis is S 111The average cross-sectional area of ​​all straight pipes in any first branch pipe 112 is set as the cross-sectional area of ​​that first branch pipe 112. Here, "cross-sectional area of ​​a straight pipe" refers to the cross-sectional area of ​​any straight pipe on a cross-section perpendicular to its own longitudinal axis. Figure 7A For example, if the number of straight pipes constituting a first branch pipe 112 is 6, then the sum of the cross-sectional areas of the 6 straight pipes is divided by 6, and the average value of the cross-sectional areas of the 6 straight pipes is set as the cross-sectional area S of the first branch pipe 112. 112 .like Figure 7A As shown, the sum of the cross-sectional areas of the two first branch pipes 112 in the first hot water pipe 11 is S. 112total In one embodiment of the present invention, S 111 / S 112 total It is 0.5 to 1. When S 111 / S 112total When the ratio is less than 0.5, the high flow velocity of the heat removal medium at the first inlet can cause surging, or the low flow velocity of the heat removal medium in the first branch pipe can lead to impurity deposition inside the pipe. On the other hand, considering the need to prevent the diameter of the main pipe at the first inlet from being too large, which would reduce the strength of the reactor wall, it is desirable that S... 111 / S 112 total The ratio is less than 1. S 111 / S 112 total The ratio is preferably 0.55 to 0.95, more preferably 0.6 to 0.9.

[0132] like Figure 7A and 7B As shown, in one embodiment of the invention, the heat dissipation pipe assembly includes at least one second heat dissipation pipe 12. The second heat dissipation pipe 12 includes a second inlet main pipe 121 and a second branch pipe 122 in fluid communication with the second inlet main pipe 121. The second branch pipe 122 includes at least two adjacent (preferably parallel to the longitudinal axis of the reactor) straight pipes and connecting fittings for connecting the at least two straight pipes in series and in fluid communication.

[0133] There is no particular limitation on the number of straight pipes that make up any second branch pipe 122, which is usually 2 to 20, preferably 2 to 16, and more preferably 2 to 12. When the number of straight pipes exceeds the above range, the evaporation rate of the heat-removing medium in the second heat-removing pipe will decrease, thereby affecting the heat-removing effect.

[0134] In one embodiment of the present invention, the cross-sectional area of ​​the second inlet main pipe 121 perpendicular to its own longitudinal axis is S. 121 The average cross-sectional area of ​​all the straight pipes in the second branch pipe 122 is set as the cross-sectional area S of the second branch pipe 122. 122 .byFigure 7A For example, if the number of straight pipes constituting the second branch pipe 122 is 8, then the sum of the cross-sectional areas of the 8 straight pipes is divided by 8, and the average value of the cross-sectional areas of the 8 straight pipes is set as the cross-sectional area S of the second branch pipe 122. 122 In one embodiment of the present invention, S 121 / S 122 It ranges from 1.0 to 1.7. When S 121 / S 122 When the ratio is less than 1, there may be surging due to the high flow velocity of the heat removal medium in the second inlet main pipe 121, or impurities depositing due to the low flow velocity of the heat removal medium in the second branch pipe 122, resulting in a poor heat removal effect. On the other hand, from a cost perspective, it is desirable that S... 121 / S 122 The ratio is below 1.7. 121 / S 122 The ratio is preferably 1.05 to 1.4, more preferably 1.1 to 1.25.

[0135] In one embodiment of the present invention, the number of first branch pipes 112 that are in fluid communication with the first inlet main pipe 111 accounts for less than 66% of the total number of first branch pipes 112 and second branch pipes 122, preferably less than 50%, and even more preferably less than 33%.

[0136] like Figure 8A and 8B As shown, in one embodiment of the present invention, the heat dissipation pipe assembly includes at least one third heat dissipation pipe 13, which includes a first outlet main pipe 131 and at least two ( Figure 8A There are 2 in the middle. Figure 8B There are at least two third branch pipes 132, each of which is in fluid communication with the first outlet main pipe 131. The first outlet main pipe 131 passes through the reactor wall 1 to receive the heat dissipation medium from each of the third branch pipes 132, thereby transporting the heat dissipation medium to the outside of the reactor. Each of the third branch pipes 132 includes at least two adjacent (preferably parallel to the longitudinal axis of the reactor) straight pipes and a connecting fitting for connecting the at least two straight pipes in series and in fluid communication.

[0137] In one embodiment of the invention, the number of third branch pipes 132 in fluid communication with the first outlet main pipe 131 is 2 to 8, preferably 2 to 6, and more preferably 2 to 4. When the number of third branch pipes 132 in fluid communication with a first outlet main pipe 131 exceeds 8, in order to supply sufficient heat dissipation medium to all the third branch pipes 132, the first outlet main pipe 131 needs to have an excessively large pipe diameter (cross-sectional area). In order for such a first inlet main pipe 131 to pass through the reactor wall, the opening on the reactor wall needs to be correspondingly enlarged, which leads to a decrease in reactor wall strength or an increase in manufacturing cost.

[0138] There is no particular limitation on the number of straight pipes constituting any one of the third branch pipes 132, which is usually 2 to 20, preferably 2 to 16, and more preferably 2 to 12. There is no particular limitation on the number of straight pipes constituting all the third branch pipes 132 in the third heat-relief pipe 13, but it is usually 4 to 160, preferably 4 to 140, and more preferably 4 to 120. When the number of straight pipes exceeds the above range, the evaporation rate of the heat-relief medium in the third heat-relief pipe will decrease, thus affecting the heat-relief effect.

[0139] In one embodiment of the present invention, the cross-sectional area of ​​the first outlet main pipe 131 perpendicular to its own longitudinal axis is S. 131 The average cross-sectional area of ​​all straight pipes in any third branch pipe 132 is set as the cross-sectional area of ​​that third branch pipe 132. Here, "cross-sectional area of ​​a straight pipe" refers to the cross-sectional area of ​​any straight pipe on a cross-section perpendicular to its own longitudinal axis. Figure 8A For example, if there are 6 straight pipes constituting a third branch pipe 132, then the sum of the cross-sectional areas of the 6 straight pipes is divided by 6, and the average value of the cross-sectional areas of the 6 straight pipes is set as the cross-sectional area S of the third branch pipe 132. 132 .like Figure 8A As shown, the sum of the cross-sectional areas of the two third branch pipes 132 in the third hot water pipe 13 is S. 132total In one embodiment of the present invention, S 131 / S 132 total It is 0.5 to 1. When S 131 / S 132total When the ratio is less than 0.5, the high flow velocity of the heat dissipation medium at the third outlet may cause surging, or the low flow velocity of the heat dissipation medium in the third branch pipe may cause impurities to deposit inside the pipe. On the other hand, considering the need to prevent the diameter of the main pipe at the first outlet from being too large, which could lead to a decrease in the reactor wall strength, it is desirable that S... 131 / S 132 total The ratio is less than 1. S 131 / S 132 total The ratio is preferably 0.55 to 0.95, more preferably 0.6 to 0.9.

[0140] like Figure 8A and 8B As shown, in one embodiment of the invention, the heat dissipation pipe assembly includes at least one fourth heat dissipation pipe 14. The fourth heat dissipation pipe 14 includes a second outlet main pipe 141 and a fourth branch pipe 142 in fluid communication with the second outlet main pipe 141. The fourth branch pipe 142 includes at least two adjacent (preferably parallel to the longitudinal axis of the reactor) straight pipes and connecting fittings for connecting the at least two straight pipes in series and in fluid communication.

[0141] There is no particular limitation on the number of straight pipes that make up any fourth branch pipe 142, which is usually 2 to 20, preferably 2 to 16, and more preferably 2 to 12. When the number of straight pipes exceeds the above range, the evaporation rate of the heat-removing medium in the fourth heat-removing pipe will decrease, thereby affecting the heat-removing effect.

[0142] In one embodiment of the present invention, the cross-sectional area of ​​the second outlet main pipe 141 perpendicular to its own longitudinal axis is S. 141 The average cross-sectional area of ​​all the straight pipes in the fourth branch pipe 142 is set as the cross-sectional area S of the fourth branch pipe 142. 142 .by Figure 8A For example, if the number of straight pipes constituting the fourth branch pipe 142 is 8, then the sum of the cross-sectional areas of each of the 8 straight pipes is divided by 8, and the average value of the cross-sectional areas of the 8 straight pipes is set as the cross-sectional area S of the fourth branch pipe 142. 142 In one embodiment of the present invention, S 141 / S 142 It ranges from 1.0 to 1.7. When S 141 / S 142 When the ratio is less than 1.0, there may be surging due to the high flow velocity of the heat removal medium in the second outlet main pipe 141, or impurities depositing due to the low flow velocity of the heat removal medium in the fourth branch pipe 142, resulting in a poor heat removal effect. On the other hand, from a cost perspective, it is desirable that S... 141 / S 142 The ratio is below 1.7. 141 / S 142 The ratio is preferably 1.05 to 1.4, more preferably 1.1 to 1.25.

[0143] In one embodiment of the present invention, the number of third branch pipes 132 that are in fluid communication with the first outlet main pipe 131 accounts for less than 66% of the total number of third branch pipes 132 and fourth branch pipes 142, preferably less than 50%, and even more preferably less than 33%.

[0144] In one embodiment of the present invention, the outer diameter of each straight pipe constituting at least one of the first branch pipe 111, the second branch pipe 112, the third branch pipe 113, and the fourth branch pipe 114 may be the same or different, and each is independently 80-180 mm, preferably 90-170 mm, and / or, the inner diameter of each straight pipe is independently 60-150 mm, preferably 70-140 mm, and / or, the length of each straight pipe is independently 4.0-13 m, preferably 5.5-12.0 m, and / or, the first inlet main pipe and the first outlet... The outer diameter of each main pipe is independently 100-270 mm, preferably 110-250 mm, and / or the inner diameter of each of the first inlet main pipe and the first outlet main pipe is independently 80-250 mm, preferably 90-230 mm, and / or the outer diameter of each of the second inlet main pipe and the second outlet main pipe is independently 100-270 mm, preferably 110-250 mm, and / or the inner diameter of each of the second inlet main pipe and the second outlet main pipe is independently 80-250 mm, preferably 90-230 mm.

[0145] In one embodiment of the invention, the first branch pipe can be used as either the third or fourth branch pipe, and the second branch pipe can also be used as either the third or fourth branch pipe. Conversely, the third branch pipe can be used as either the first or second branch pipe, and similarly, the fourth branch pipe can also be used as either the first or second branch pipe. In other words, the first inlet main pipe can be in fluid communication with at least two branch pipes selected from the third and fourth branch pipes, and the second inlet main pipe can be in fluid communication with any one of the third and fourth branch pipes. Conversely, the first outlet main pipe can be in fluid communication with at least two branch pipes selected from the first and second branch pipes, and the second outlet main pipe can be in fluid communication with any one of the first and second branch pipes.

[0146] According to one embodiment of the present invention, a method for adjusting the temperature of a fluidized bed reactor, the fluidized bed reactor including the heat removal tube assembly of the present invention, the method comprising: adjusting the temperature of the fluidized bed reactor by switching between the first heat removal tube 10 and the second heat removal tube 20 during the reaction process.

[0147] The method for adjusting the temperature of a fluidized bed reactor according to the present invention can adjust the temperature of the fluidized bed reactor in a range of 0.1-2℃, preferably 0.5-1℃.

[0148] According to one embodiment of the invention, the use of the fluidized bed reactor as described in any of the preceding aspects of the invention in the production of epoxides or unsaturated nitriles via olefin oxidation or ammonia oxidation is also relevant. Here, the olefin is, in particular, propylene; the epoxide is, in particular, propylene oxide; and the unsaturated nitrile is, in particular, acrylonitrile.

[0149] According to one embodiment of the present invention, a method for producing acrylonitrile is particularly relevant, the method comprising the step of subjecting propylene to an ammoxidation reaction in a fluidized bed reactor as described in any preceding aspect of the present invention to produce acrylonitrile.

[0150] According to one embodiment of the present invention, the olefin oxidation or ammonia oxidation process can be carried out in any manner and method conventionally known in the art, which is known to those skilled in the art and will not be repeated here. However, specific operating conditions for the ammonia oxidation reaction include, for example, a molar ratio of propylene / ammonia / air of generally 1:1.05-1.3:1.8-2.0 (8.5-9.6 for molecular oxygen, and for air), a reaction temperature of generally 420-440°C, a reaction pressure (gauge pressure) of generally 0.03-0.14 MPa, and a WWH (weight hourly space velocity) of generally 0.04-0.10 h⁻¹ for the catalyst. -1 .

[0151] Example

[0152] The present invention will be further described in detail below through embodiments and comparative examples, but the present invention is not limited to the following embodiments.

[0153] In the following examples and comparative examples, the acrylonitrile yield and propylene conversion rate can be calculated using the following formulas:

[0154] Acrylonitrile yield: AN% = C AN / ΣC*100

[0155] Propylene conversion rate: Cc3% = (1-Cc) 3出 / Cc 3进 )*100

[0156] in:

[0157] C AN The number of moles of carbon (mol) in AN in the reactor outlet gas.

[0158] ΣC: Total number of carbon moles in the reactor outlet gas (mol)

[0159] Cc 3出 The number of moles of carbon (mol) in the C3 content of the gas exiting the reactor.

[0160] Cc 3出 : The number of moles of carbon (mol) in the C3 inlet gas of the reactor.

[0161] Example 1

[0162] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. It contains 480 straight tubes of uniform height, divided into 44 heat dissipation tubes, of which 12 use [a specific heat dissipation method / approach]. Figure 4A The arrangement of the pipes results in 7.6 straight pipes per unit area in the cross-section at the center point of the heat dissipation section. 2 The outer diameter of the heat dissipation tube is 89mm, and the L1 / S1 ratio is 2.1 / m.

[0163] With a propylene feed rate of 7700 NM 3 At a reaction temperature of 430℃ and a reaction pressure of 0.06 MPa, with a propylene:ammonia:air ratio of 1:1.05:9.2 (based on air), the heat removal rate is 1.24 t / m³ of 4.0 MPa saturated steam per hour. 2 .

[0164] Example 2

[0165] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. It contains 584 straight tubes of uniform height, divided into 56 heat dissipation tubes, of which 44 heat dissipation tubes utilize... Figure 4B The arrangement of the pipes results in 9.2 straight pipes per unit area in the cross-section at the center point of the heat dissipation section. 2 The outer diameter of the heat dissipation tube is 114mm, and the L1 / S1 ratio is 3.3 / m.

[0166] With a propylene feed rate of 7700 NM 3 At a reaction temperature of 430℃ and a reaction pressure of 0.06 MPa, with a propylene:ammonia:air ratio of 1:1.05:9.2, the heat removal rate is 1.24 t / h of 4.5 MPa steam / m³. 2 .

[0167] Example 3

[0168] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. It contains 572 straight tubes of uniform height, divided into 52 heat dissipation tubes, of which 44 heat dissipation tubes utilize... Figure 4A Alternatively, for either of the two arrangement methods shown in 4C, the number of straight pipes per unit area in the cross-section at the center point of the heat dissipation section is 9.0 per m. 2 Each group consists of 6, 10, or 12 heat dissipation pipes connected in series via straight pipe connectors. The outer diameter of the heat dissipation pipe is 140mm, and the L1 / S1 ratio is 4.0.

[0169] With a propylene feed rate of 11800 NM 3At a reaction temperature of 430℃ and a reaction pressure of 0.06 MPa, with a propylene:ammonia:air ratio of 1:1.05:9.2, the heat removal rate is 1.98 t / h of 4.5 MPa steam / m³. 2 .

[0170] Example 4

[0171] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. It contains 732 straight tubes of uniform height, divided into 70 heat dissipation tubes, of which 60 heat dissipation tubes utilize... Figure 4A Alternatively, as shown in 4C, the number of straight pipes per unit area in the cross-section at the center point of the heat dissipation section is 11.5 per m. 2 Each group consists of 6, 10, or 12 heat dissipation pipes connected in series via straight pipe connectors. The outer diameter of the heat dissipation pipe is 140mm, and the L1 / S1 ratio is 5.1.

[0172] With a propylene feed rate of 11800 NM 3 At a reaction temperature of 430℃ and a reaction pressure of 0.06 MPa, with a propylene:ammonia:air ratio of 1:1.05:9.2, the heat removal per hour is 2.01 t of 4.5 MPa steam / m³. 2 .

[0173] Example 5

[0174] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. It contains 732 straight tubes of uniform height, divided into 70 heat dissipation tubes, of which 52 heat dissipation tubes utilize... Figure 4A Alternatively, as shown in 4C, the number of straight pipes per unit area in the cross-section at the center point of the heat dissipation section is 11.5 per m. 2 Each group consists of 6, 10, or 12 heat dissipation pipes connected in series via straight pipe connectors. The outer diameter of the heat dissipation pipe is 89 mm, and the L1 / S1 ratio is 3.2.

[0175] With a propylene feed rate of 11800 NM 3 At a reaction temperature of 430℃ and a reaction pressure of 0.06 MPa, with a propylene:ammonia:air ratio of 1:1.05:9.2, the heat removal rate is 1.98 t / h of 4.5 MPa steam / m³. 2 .

[0176] Comparative Example 1

[0177] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. It contains 380 straight pipes of uniform height, divided into 36 groups.Figure 2 The heat dissipation pipe arrangement has a straight pipe count of 6.0 per unit area in the cross-section at the center point of the heat dissipation section. 2 The outer diameter of the heat dissipation tube is 89mm, and the L1 / S1 ratio is 1.67 / m.

[0178] With a propylene feed rate of 11800 NM 3 At a reaction temperature of 430℃ and a reaction pressure of 0.06 MPa, with a propylene:ammonia:air ratio of 1:1.05:9.2, the heat removal rate is 1.98 t / h of 4.5 MPa steam / m³. 2 During the operation of the device, the heat removal tube group cannot stably control the reaction temperature. Due to the insufficient number of heat removal tubes, the long-term stable operation of the device cannot be guaranteed.

[0179] Comparative Example 2

[0180] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. It contains 584 straight tubes of uniform height, divided into 56 heat dissipation tubes. The heat collection tubes are arranged in a manner such that the number of straight tubes per unit area at the center point of the heat dissipation section is 9.18 tubes / m. 2 Each group consists of 6, 10, or 12 heat dissipation pipes connected in series via straight pipe connectors. The outer diameter of the heat dissipation pipe is 140mm, and the L1 / S1 ratio is 4.04 / m.

[0181] With a propylene feed rate of 11800 NM 3 At a reaction temperature of 430℃ and a reaction pressure of 0.06 MPa, with a propylene:ammonia:air ratio of 1:1.05:9.2, the heat removal rate is 1.98 t steam / m³. 2 .

[0182] Although the equipment can meet the requirements for normal operation, it cannot meet the requirements for maintenance and repair of internal components when the equipment is shut down.

[0183] Example 6:

[0184] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. It contains 416 straight pipes of uniform height, divided into 44 heat dissipation pipes. One heat dissipation pipe is a first heat dissipation pipe consisting of 6 straight pipes (a) connected in series. The four straight pipes (a) of this first heat dissipation pipe are located within 3 / 4 of the radius (3 / 4R) of the cross-section of the reactor's heat dissipation section. The other heat dissipation pipe is a second heat dissipation pipe consisting of 6 straight pipes (b). The four straight pipes (b) of this second heat dissipation pipe are located outside the 3 / 4R range of the cross-section of the reactor's heat dissipation section. The ratio of the outer diameter of branch pipe (a) to that of branch pipe (b) is 1, and the ratio of the total circumference of all straight pipes (a) constituting the first heat dissipation pipe to the total circumference of the straight pipes (b) constituting the second heat dissipation pipe is also 1.

[0185] With a propylene feed rate of 7700 NM 3 Under the conditions of a reaction rate of 1 / h, a reaction temperature of 430℃, a reaction pressure of 0.06Mpa, and a propylene:ammonia:air ratio of 1:1.05:9.2, the reactor temperature can be adjusted in increments of 1.5℃ by switching between any one of the first and second heat-removing tubes.

[0186] Example 7

[0187] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. It contains 584 straight pipes of uniform height, divided into 56 heat dissipation pipes. One heat dissipation pipe is the first heat dissipation pipe, consisting of 7 straight pipes (a) connected in series. Five of the straight pipes (a) in this first heat dissipation pipe are located within 2 / 3R of the distance from the center of the reactor's heat dissipation section cross-section. The other heat dissipation pipe is the second heat dissipation pipe, consisting of 8 straight pipes (b) connected in series. Five of the straight pipes (b) in this second heat dissipation pipe are located outside the 2 / 3R distance from the center of the reactor's heat dissipation section cross-section. The ratio of the outer diameter of branch pipe (a) to that of branch pipe (b) is 1.3, and the ratio of the total circumference of all straight pipes (a) constituting the first heat dissipation pipe to the total circumference of the straight pipes (b) constituting the second heat dissipation pipe is 1.12.

[0188] With a propylene feed rate of 11800 NM 3 Under the conditions of a reaction rate of 1 / h, a reaction temperature of 430℃, a reaction pressure of 0.06Mpa, and a propylene:ammonia:air ratio of 1:1.05:9.2, the reactor temperature can be adjusted by 0.8℃ by switching between any one of the first and second heat dissipation tubes.

[0189] Example 8

[0190] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. It contains 584 straight tubes of uniform height, divided into 56 heat dissipation tubes. One heat dissipation tube is the first heat dissipation tube, consisting of 12 straight tubes (a) connected in series. Ten of these straight tubes (a) are located within 2 / 3R of the center of the reactor's heat dissipation section cross-section. The other heat dissipation tube is the second heat dissipation tube, consisting of 8 straight tubes (b) connected in series. Six of these straight tubes (b) are located outside 2 / 3R of the center of the reactor's heat dissipation section cross-section. The ratio of the outer diameter of branch tube (b) to that of branch tube (a) is 1.5, and the ratio of the total circumference of all straight tubes constituting the first heat dissipation tube to that of the straight tubes constituting the second heat dissipation tube is 1.05.

[0191] With a propylene feed rate of 11800 NM 3 Under the conditions of a reaction rate of 1 / h, a reaction temperature of 430℃, a reaction pressure of 0.06Mpa, and a propylene:ammonia:air ratio of 1:1.05:9.2, the reactor temperature can be adjusted within a range of 0.5℃ by switching between any one of the first and second heat dissipation tubes.

[0192] Example 9

[0193] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. It contains 584 straight tubes of uniform height, divided into 56 heat dissipation tubes. One heat dissipation tube is the first heat dissipation tube, consisting of 12 straight tubes (a) connected in series. Ten of these straight tubes (a) are located within 2 / 3R of the center of the reactor's heat dissipation section cross-section. The other heat dissipation tube is the second heat dissipation tube, consisting of 19 straight tubes (b) connected in series. Eight of these straight tubes (b) are located outside 2 / 3R of the center of the reactor's heat dissipation section cross-section. The ratio of the outer diameter of tube a to that of tube b is 1.7, and the ratio of the total circumference of all the straight tubes constituting the first heat dissipation tube to that constituting the second heat dissipation tube is 1.08.

[0194] With a propylene feed rate of 11800 NM 3 Under the conditions of a reaction rate of 1 / h, a reaction temperature of 430℃, a reaction pressure of 0.06Mpa, and a propylene:ammonia:air ratio of 1:1.05:9.2, the reactor temperature can be adjusted within a range of 0.7℃ by switching between any one of the first and second heat-removing tubes.

[0195] Comparative Example 3:

[0196] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. It contains 584 straight tubes of uniform height, divided into 56 heat dissipation tubes. One heat dissipation tube is the first heat dissipation tube, consisting of 12 straight tubes (a) connected in series. Ten of these straight tubes (a) are located within 2 / 3R of the center of the reactor's heat dissipation section cross-section. The other heat dissipation tube is the second heat dissipation tube, consisting of 8 straight tubes (b) connected in series. Four of these straight tubes (b) are located outside 2 / 3R of the center of the reactor's heat dissipation section cross-section. The ratio of the outer diameter of tube a to that of tube b is 1.2, and the ratio of the total circumference of all the straight tubes constituting the first heat dissipation tube to that constituting the second heat dissipation tube is 1.9.

[0197] With a propylene feed rate of 11800 NM 3 Under the conditions of a reaction temperature of 430℃, a reaction pressure of 0.06MPa, and a propylene:ammonia:air ratio of 1:1.05:9.2, the reactor temperature can only be adjusted by a margin of 7.8℃ by switching between any one of the first and second heat dissipation tubes.

[0198] Comparative Example 4:

[0199] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. It contains 584 straight tubes of uniform height, divided into 56 heat dissipation tubes. One heat dissipation tube is the first heat dissipation tube, consisting of 12 straight tubes (a) connected in series. Ten of these straight tubes (a) are located within 2 / 3R of the center of the reactor's heat dissipation section cross-section. The other heat dissipation tube is the second heat dissipation tube, consisting of 8 straight tubes (b) connected in series. Four of these straight tubes (b) are located within 2 / 3R of the center of the reactor's heat dissipation section cross-section. The ratio of the outer diameter of tube a to that of tube b is 1.2, and the ratio of the total circumference of all the straight tubes constituting the first heat dissipation tube to that constituting the second heat dissipation tube is 1.64.

[0200] With a propylene feed rate of 11800 NM 3 Under the conditions of a reaction rate of 1:1.05:9.2, a reaction temperature of 430℃, a reaction pressure of 0.06Mpa, and a propylene:ammonia:air ratio of 1:1.05:9.2, the reactor temperature can only be adjusted by a margin of 6.3℃ by switching between the first and second heat dissipation tubes.

[0201] Example 10

[0202] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. The reactor's heat dissipation section has eight sets of first heat dissipation pipes. In any one of these first heat dissipation pipes, the first inlet main pipe is fluidly connected to two first branch pipes. Each first branch pipe consists of 12 adjacent straight pipes. The inner diameter of the first inlet main pipe is 130 mm, and the inner diameter of the first branch pipe is 100 mm. The ratio of the cross-sectional area of ​​the first inlet main pipe to the sum of the cross-sectional areas of the two first branch pipes is 0.85.

[0203] With a propylene feed rate of 11800 NM 3 Under the conditions of a reaction rate of 1 / h, a reaction temperature of 430℃, a reaction pressure of 0.06Mpa, and a propylene:ammonia:air ratio of 1:1.05:9.2, the reactor temperature can be maintained within the normal range during one operating cycle of the unit. By switching between different heat dissipation tubes, the reactor temperature can be adjusted by as little as 1.5℃.

[0204] Example 11

[0205] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. The reactor's heat dissipation section has 12 sets of first heat dissipation pipes. In any one of these first heat dissipation pipes, the first inlet main pipe is fluidly connected to three first branch pipes. Each first branch pipe consists of 10 adjacent straight pipes. The inner diameter of the first inlet main pipe is 100 mm, and the inner diameter of the first branch pipe is 80 mm. The ratio of the cross-sectional area of ​​the first inlet main pipe to the sum of the cross-sectional areas of the three first branch pipes is 0.52.

[0206] With a propylene feed rate of 11800 NM3 / h, a reaction temperature of 430℃, a reaction pressure of 0.06 MPa, and a propylene:ammonia:air ratio of 1:1.05:9.2, the reactor temperature can be maintained within the normal range during one operating cycle of the unit. By switching between different heat dissipation tubes, the reactor temperature can be adjusted by as little as 1.2℃.

[0207] Comparative Example 5

[0208] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. The reactor's heat dissipation section has eight sets of first heat dissipation pipes. In any one of these first heat dissipation pipes, the first inlet main pipe is fluidly connected to three first branch pipes. Each first branch pipe consists of eight adjacent straight pipes. The inner diameter of the first inlet main pipe is 140 mm, and the inner diameter of the first branch pipe is 120 mm. The ratio of the cross-sectional area of ​​the first inlet main pipe to the sum of the cross-sectional areas of the three first branch pipes is 0.45.

[0209] Under the conditions of propylene feed rate of 11800 NM3 / h, reaction temperature of 430℃, reaction pressure of 0.06 MPa, and propylene:ammonia:air ratio of 1:1.05:9.2, there is a risk that the heat removal efficiency will decrease or even the heat removal pipe will become blocked and fail due to the accumulation of deposits on the inner wall of the heat removal pipe, requiring shutdown for maintenance.

[0210] Example 12

[0211] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. The reactor's deheating section consists of 12 sets of first deheating pipes and 12 sets of second deheating pipes. In any one first deheating pipe, the first inlet main pipe is fluidly connected to three first branch pipes. Each first branch pipe consists of eight adjacent straight pipes. The inner diameter of the first inlet main pipe is 150 mm, and the inner diameter of the first branch pipe is 100 mm. The ratio of the cross-sectional area of ​​the first inlet main pipe to the sum of the cross-sectional areas of the three first branch pipes is 0.75. In any one second deheating pipe, the second inlet main pipe is fluidly connected to one second branch pipe, and each second branch pipe consists of ten adjacent straight pipes connected in series. The inner diameter of the second inlet main pipe is 110 mm, and the inner diameter of the second branch pipe is 100 mm. The ratio of the cross-sectional area of ​​the second inlet main pipe to the sum of the cross-sectional areas of the second branch pipe is 1.1.

[0212] Under the conditions of a propylene feed rate of 11800 NM3 / h, a reaction temperature of 430℃, a reaction pressure of 0.06 MPa, and a propylene:ammonia:air ratio of 1:1.05:9.2, the reactor temperature can be maintained within the normal range during one operating cycle of the unit.

[0213] Example 13

[0214] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. The reactor's deheating section has eight sets of third deheating pipes. In any one of these third deheating pipes, the first outlet main pipe is fluidly connected to two third branch pipes. Each third branch pipe consists of 12 adjacent straight pipes. The inner diameter of the first outlet main pipe is 130 mm, and the inner diameter of the third branch pipes is 100 mm. The ratio of the cross-sectional area of ​​the first outlet main pipe to the sum of the cross-sectional areas of the two third branch pipes is 0.85.

[0215] With a propylene feed rate of 11800 NM 3 Under the conditions of a reaction rate of 1 / h, a reaction temperature of 430℃, a reaction pressure of 0.06 MPa, and a propylene:ammonia:air ratio of 1:1.05:9.2, the reactor operates stably within one operating cycle of the unit.

[0216] Comparative Example 6

[0217] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. The reactor's deheating section has eight sets of third deheating pipes. In any one of these third deheating pipes, the first outlet main pipe is fluidly connected to three third branch pipes. Each third branch pipe consists of eight adjacent straight pipes. The inner diameter of the first outlet main pipe is 140 mm, and the inner diameter of each third branch pipe is 120 mm. The ratio of the cross-sectional area of ​​the first outlet main pipe to the sum of the cross-sectional areas of the three third branch pipes is 0.45.

[0218] Under the conditions of propylene feed rate of 11800 NM3 / h, reaction temperature of 430℃, reaction pressure of 0.06 MPa, and propylene:ammonia:air ratio of 1:1.05:9.2, there is a risk that the heat removal efficiency of the third heat removal pipe will decrease or even become blocked and fail due to the accumulation of deposits on the inner wall of the heat removal pipe, requiring shutdown for maintenance.

[0219] Example 14

[0220] The fluidized bed reactor has a diameter of 9 meters and is loaded with 180 tons of SANC series acrylonitrile catalyst from the Shanghai Research Institute of Petrochemical Technology, Sinopec. The reactor's deheating section consists of 12 sets of third deheating pipes and 12 fourth deheating pipes. In any third deheating pipe, the first outlet main pipe is fluidly connected to three third branch pipes. Each third branch pipe consists of eight adjacent straight pipes. The inner diameter of the first outlet main pipe is 150 mm, and the inner diameter of the third branch pipe is 100 mm. The ratio of the cross-sectional area of ​​the first outlet main pipe to the sum of the cross-sectional areas of the three first branch pipes is 0.75. In any second deheating pipe, the second outlet main pipe is fluidly connected to one fourth branch pipe, and each fourth branch pipe consists of ten adjacent straight pipes connected in series. The inner diameter of the second outlet main pipe is 110 mm, and the inner diameter of the fourth branch pipe is 100 mm. The ratio of the cross-sectional area of ​​the second outlet main pipe to the cross-sectional area of ​​the fourth branch pipe is 1.1.

[0221] Under the conditions of a propylene feed rate of 11800 NM3 / h, a reaction temperature of 430℃, a reaction pressure of 0.06 MPa, and a propylene:ammonia:air ratio of 1:1.05:9.2, the reactor temperature can be maintained within the normal range during one operating cycle of the unit.

Claims

1. A heat removal tube assembly for removing heat from a reactor or supplying heat to the reactor, characterized in that, Includes at least one first heat-reducing pipe, the first heat-reducing pipe comprising: A first inlet pipe, which enters the reactor from the outside of the reactor through the reactor wall; and At least two first branch pipes are in fluid communication with the first inlet main pipe, each of the first branch pipes comprising at least two adjacent straight pipes and a connecting fitting for connecting the at least two straight pipes in series and in fluid communication. Wherein, if the average of the cross-sectional areas of all the straight pipes in any one of the first branch pipes on the cross section perpendicular to their respective longitudinal axes is the cross-sectional area of ​​the first branch pipe, then the ratio of the cross-sectional area of ​​the first inlet main pipe perpendicular to the longitudinal axis of the first inlet main pipe to the sum of the cross-sectional areas of all the first branch pipes is 0.5-1.

2. The heat dissipation tube assembly according to claim 1, characterized in that, The ratio of the cross-sectional area of ​​the first inlet main pipe perpendicular to its longitudinal axis to the sum of the cross-sectional areas of all the first branch pipes is 0.6-0.

9.

3. The heat dissipation tube assembly according to claim 1, characterized in that, The number of the first branch pipes is 2-8, and / or Each of the first branch pipes includes 2 to 20 of the straight pipes.

4. The heat dissipation tube assembly according to claim 1, characterized in that, The number of the first branch pipes is 2-4, and / or any one of the first branch pipes includes 2-12 of the straight pipes.

5. The heat dissipation tube assembly according to claim 1, characterized in that, The total number of straight pipes in all the first branch pipes is 4-160.

6. The heat dissipation tube assembly according to claim 1, characterized in that, The total number of straight pipes in all the first branch pipes is 4-120.

7. The heat dissipation tube assembly according to claim 1, characterized in that, It also includes at least one second heat-reducing pipe, which comprises: A second inlet manifold, which enters the reactor from the outside of the reactor through the reactor wall; and A second branch pipe in fluid communication with the second inlet main pipe, the second branch pipe comprising at least two adjacent straight pipes and a connecting fitting for connecting the at least two straight pipes in series and in fluid communication. Wherein, if the average of the cross-sectional areas of all the straight pipes in the second branch pipe on the cross section perpendicular to their respective longitudinal axes is the cross-sectional area of ​​the second branch pipe, then the ratio of the cross-sectional area of ​​the second inlet main pipe perpendicular to the longitudinal axis of the second inlet main pipe to the cross-sectional area of ​​the second branch pipe is 1.0-1.

7.

8. The heat dissipation pipe assembly according to claim 7, characterized in that, The ratio of the cross-sectional area of ​​the second inlet main pipe perpendicular to its longitudinal axis to the cross-sectional area of ​​the second branch pipe is 1.10-1.

25.

9. The heat dissipation pipe assembly according to claim 7, characterized in that, The second branch pipe includes 2-20 of the aforementioned straight pipes.

10. The heat dissipation tube assembly according to claim 7, characterized in that, The second branch pipe includes 2-12 of the straight pipes.

11. The heat dissipation tube assembly according to claim 7, characterized in that, The number of the first branch pipes accounts for less than 66% of the total number of the first branch pipes and the second branch pipes.

12. The heat dissipation pipe assembly according to claim 7, characterized in that, The number of the first branch pipes accounts for less than 33% of the total number of the first branch pipes and the second branch pipes.

13. The heat dissipation tube assembly according to claim 1, characterized in that, Includes at least one third heat-reducing pipe, which includes: The first outlet pipe extends from inside the reactor, through the reactor wall, to the outside of the reactor. At least two third branch pipes are in fluid communication with the first outlet main pipe, each of the third branch pipes comprising at least two adjacent straight pipes and a connecting fitting for connecting the at least two straight pipes in series and in fluid communication. Wherein, if the average of the cross-sectional areas of all the straight pipes in any third branch pipe on the cross section perpendicular to their respective longitudinal axes is the cross-sectional area of ​​the third branch pipe, then the ratio of the cross-sectional area of ​​the first outlet main pipe perpendicular to its longitudinal axis to the sum of the cross-sectional areas of all the third branch pipes is 0.5-1.

14. The heat dissipation tube assembly according to claim 13, characterized in that, The ratio of the cross-sectional area of ​​the first outlet main pipe perpendicular to its longitudinal axis to the sum of the cross-sectional areas of all the third branch pipes is 0.6-0.

9.

15. The heat dissipation tube assembly according to claim 13, characterized in that, The number of the third branch pipes is 2-8, and / or Each of the third branch pipes comprises 2 to 20 of the straight pipes.

16. The heat dissipation tube assembly according to claim 13, characterized in that, The number of the third branch pipes is 2-4, and / or any one of the third branch pipes includes 2-12 of the straight pipes.

17. The heat dissipation tube assembly according to claim 13, characterized in that, The total number of straight pipes in all the third branch pipes is 4-160.

18. The heat dissipation tube assembly according to claim 13, characterized in that, The total number of straight pipes in all the third branch pipes is 4-120.

19. The heat dissipation tube assembly according to claim 13, characterized in that, It also includes at least one fourth heat-reducing tube, which comprises: A second outlet pipe extends from inside the reactor, through the reactor wall, to the outside of the reactor; and A fourth branch pipe in fluid communication with the second outlet main pipe, the fourth branch pipe comprising at least two adjacent straight pipes and a connecting fitting for connecting the at least two straight pipes in series and in fluid communication. Wherein, the average of the cross-sectional areas of all the straight pipes in the fourth branch pipe on the cross section perpendicular to their respective longitudinal axes is the cross-sectional area of ​​the fourth branch pipe, and the ratio of the cross-sectional area of ​​the second outlet main pipe perpendicular to the longitudinal axis of the second outlet main pipe to the cross-sectional area of ​​the fourth branch pipe is 1.0-1.

7.

20. The heat dissipation tube assembly according to claim 19, characterized in that, The ratio of the cross-sectional area of ​​the second outlet main pipe perpendicular to its longitudinal axis to the cross-sectional area of ​​the fourth branch pipe is 1.10-1.

25.

21. The heat dissipation tube assembly according to claim 19, characterized in that, The fourth branch pipe includes 2-20 of the straight pipes.

22. The heat dissipation tube assembly according to claim 19, characterized in that, The fourth branch pipe includes 2-12 of the straight pipes.

23. The heat dissipation tube assembly according to claim 19, characterized in that, The number of the third branch pipes that are in fluid communication with the first outlet main pipe accounts for less than 66% of the total number of the third branch pipes and the fourth branch pipes.

24. The heat dissipation tube assembly according to claim 19, characterized in that, The number of the third branch pipes that are in fluid communication with the first outlet main pipe accounts for less than 33% of the total number of the third branch pipes and the fourth branch pipes.

25. A heat removal tube assembly for removing heat from or supplying heat to a reactor, characterized in that, include: At least one first inlet pipe, which penetrates the reactor wall and enters the reactor interior. At least one first outlet pipe, which penetrates the reactor wall and enters the reactor interior, and At least two branch pipes, each of which comprises at least two adjacent straight pipes parallel to the longitudinal axis of the reactor and a connecting fitting for connecting the at least two straight pipes in series and allowing fluid communication. Any one of the first inlet main pipes is in fluid communication with two or more of the branch pipes, and Any one of the first outlet main pipes is in fluid communication with two or more of the branch pipes. Wherein, let the average of the cross-sectional areas of all the straight pipes in any branch pipe connected to the first inlet main pipe on a cross section perpendicular to their respective longitudinal axes be the cross-sectional area of ​​that branch pipe, then the ratio of the cross-sectional area of ​​the first inlet main pipe perpendicular to its longitudinal axis to the sum of the cross-sectional areas of all the branch pipes fluidly connected to the first inlet main pipe is 0.5-1, and Wherein, if the average of the cross-sectional areas of all the straight pipes in any branch pipe connected to the first outlet main pipe on the cross section perpendicular to their respective longitudinal axes is the cross-sectional area of ​​the branch pipe, then the ratio of the cross-sectional area of ​​the first outlet main pipe perpendicular to its longitudinal axis to the sum of the cross-sectional areas of all the branch pipes fluidly connected to the first outlet main pipe is 0.5-1.

26. The heat dissipation tube assembly according to claim 25, characterized in that, The ratio of the cross-sectional area of ​​the first inlet main pipe perpendicular to its longitudinal axis to the sum of the cross-sectional areas of all branch pipes in fluid communication with the first inlet main pipe is 0.6-0.

9.

27. The heat dissipation tube assembly according to claim 25, characterized in that, The ratio of the cross-sectional area of ​​the first outlet main pipe perpendicular to its longitudinal axis to the sum of the cross-sectional areas of all branch pipes in fluid communication with the first outlet main pipe is 0.6-0.

9.

28. The heat dissipation tube assembly according to claim 25, characterized in that, The number of branches is 2-8, and / or Each of the branch pipes comprises 2 to 20 of the straight pipes.

29. The heat dissipation tube assembly according to claim 25, characterized in that, The number of branch pipes is 2-4, and / or any one of the branch pipes includes 2-12 of the straight pipes.

30. The heat dissipation tube assembly according to claim 25, characterized in that, The total number of straight pipes in all the branch pipes is 4-160.

31. The heat dissipation tube assembly according to claim 25, characterized in that, The total number of straight pipes in all the branch pipes is 4-120.

32. The heat dissipation tube assembly according to claim 25, characterized in that, Also includes: At least one second entry supervisor, and At least one second export supervisor, of which Any one of the second inlet main pipes is in fluid communication with one of the branch pipes, and Any one of the second outlet main pipes is in fluid communication with one of the branch pipes. Wherein, the ratio of the cross-sectional area of ​​any one of the second inlet main pipes perpendicular to its longitudinal axis to the average cross-sectional area of ​​all the straight pipes in the branch pipes fluidly connected to the second inlet main pipe on their respective cross-sections perpendicular to their longitudinal axes is 1.0-1.7, and The ratio of the cross-sectional area of ​​any one of the second outlet main pipes perpendicular to the longitudinal axis of the second outlet main pipe to the average cross-sectional area of ​​all the straight pipes in the branch pipes fluidly connected to the second outlet main pipe on the cross-section perpendicular to the longitudinal axis of the reactor is 1.0-1.

7.

33. The heat dissipation tube assembly according to claim 32, characterized in that, The ratio of the cross-sectional area of ​​any one of the second inlet main pipes perpendicular to its longitudinal axis to the average cross-sectional area of ​​all the straight pipes in the branch pipes fluidly connected to the second inlet main pipe on their respective cross-sections perpendicular to their longitudinal axes is 1.10-1.

25.

34. The heat dissipation tube assembly according to claim 32, characterized in that, The ratio of the cross-sectional area of ​​any one of the second outlet main pipes perpendicular to the longitudinal axis of the second outlet main pipe to the average cross-sectional area of ​​all the straight pipes in the branch pipes fluidly connected to the second outlet main pipe on the cross-section perpendicular to the longitudinal axis of the reactor is 1.10-1.

25.

35. The heat dissipation tube assembly according to claim 25, characterized in that, The number of branch pipes that are in fluid communication with the first outlet main pipe accounts for less than 66% of the total number of branch pipes.

36. The heat dissipation tube assembly according to claim 25, characterized in that, The number of branch pipes that are in fluid communication with the first outlet main pipe accounts for less than 33% of the total number of branch pipes.

37. A reactor, characterized in that, The reactor includes the heat removal tube assembly as described in any one of claims 1-36.

38. A method for heat removal from a reactor, characterized in that, The heat generated by the reaction in the reactor is recovered using the heat-relief tube assembly according to any one of claims 1-36, or the heat required for the reaction is provided to the reactor using the heat-relief tube assembly according to any one of claims 1-36.

39. Use of the heat-relief tube assembly according to any one of claims 1-36 in a fluidized bed reactor for the production of epoxides or unsaturated nitriles by olefin oxidation or ammonia oxidation.

40. A method for producing unsaturated nitrile, comprising the step of subjecting an olefin to an ammoxidation reaction in a fluidized bed reactor to generate unsaturated nitrile, said fluidized bed reactor comprising the heat removal tube assembly as described in any one of claims 1-36.

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