CN112745884B - Heat-conducting furnace tube, preparation method and application in cracking furnace - Google Patents

Heat-conducting furnace tube, preparation method and application in cracking furnace Download PDF

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CN112745884B
CN112745884B CN201911038442.4A CN201911038442A CN112745884B CN 112745884 B CN112745884 B CN 112745884B CN 201911038442 A CN201911038442 A CN 201911038442A CN 112745884 B CN112745884 B CN 112745884B
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furnace tube
heat
furnace
conducting
main body
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CN112745884A (en
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刘俊杰
杨士芳
王国清
张利军
周丛
张兆斌
杜志国
李晓锋
杨沙沙
郭莹
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Sinopec Beijing Research Institute of Chemical Industry
China Petroleum and Chemical Corp
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Sinopec Beijing Research Institute of Chemical Industry
China Petroleum and Chemical Corp
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    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
    • C10G9/14—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils in pipes or coils with or without auxiliary means, e.g. digesters, soaking drums, expansion means
    • C10G9/18—Apparatus
    • C10G9/20—Tube furnaces
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C4/00—Preparation of hydrocarbons from hydrocarbons containing a larger number of carbon atoms
    • C07C4/02—Preparation of hydrocarbons from hydrocarbons containing a larger number of carbon atoms by cracking a single hydrocarbon or a mixture of individually defined hydrocarbons or a normally gaseous hydrocarbon fraction
    • C07C4/04—Thermal processes
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
    • C10G9/14—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils in pipes or coils with or without auxiliary means, e.g. digesters, soaking drums, expansion means
    • C10G9/16—Preventing or removing incrustation
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
    • C10G9/14—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils in pipes or coils with or without auxiliary means, e.g. digesters, soaking drums, expansion means
    • C10G9/18—Apparatus
    • C10G9/20—Tube furnaces
    • C10G9/203—Tube furnaces chemical composition of the tubes
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/08—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tubular bodies or pipes
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/10—Oxidising
    • C23C8/16—Oxidising using oxygen-containing compounds, e.g. water, carbon dioxide
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/10—Process efficiency

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

Abstract

The invention relates to the field of heat-conducting furnace tubes for ethylene cracking furnaces, and discloses a heat-conducting furnace tube, a preparation method and application thereof in a cracking furnace. The heat-conducting furnace tube comprises a furnace tube main body, wherein the inner side wall of the furnace tube main body is provided with a plurality of groups of heat-conducting components which are sequentially and repeatedly arranged along the length direction of the furnace tube main body; the heat conduction component comprises a plurality of first heat conduction pieces formed by surrounding a circle along the cross section of the inner wall of the furnace tube main body and second heat conduction pieces arranged spirally along the axial direction of the furnace tube main body. The heat conducting member is mainly applied to the front 1/3 part of the cracking furnace tube. The heat-conducting furnace tube has good heat transfer effect, remarkably improves the heat transfer strengthening comprehensive factor of the heat-transferring furnace tube, and can effectively reduce the coking amount and the carburization phenomenon of the heat-transferring furnace tube.

Description

Heat-conducting furnace tube, preparation method and application in cracking furnace
Technical Field
The invention relates to the field of heat-conducting furnace tubes for ethylene cracking furnaces, in particular to a heat-conducting furnace tube, a preparation method and application in a cracking furnace.
Background
The cracking furnace is an important device in petrochemical industry, is mainly used for heating cracking raw materials to realize cracking reaction, and is beneficial to primary reaction of target products such as ethylene generated by cracking through high temperature, short retention time and low hydrocarbon partial pressure according to the analysis of cracking principle.
For shortening the retention time of the cracking raw material in the cracking furnace tube, the method of increasing the treatment capacity of the furnace tube, reducing the tube diameter of the furnace tube and reducing the tube length can be adopted. However, the first two methods also result in a corresponding increase in pressure drop, thus partially offsetting the effect of the reduction in residence time, and are rarely used alone because of the reduced selectivity of cracking that results from the increased pressure drop. The preferred option for reducing the residence time is to reduce the tube length so that for a single pass cracking furnace tube, the residence time of the cracking feedstock in the tube is less than 0.1 s. Therefore, for a furnace tube having a small tube length, it is necessary to improve the heat transfer performance of the furnace tube in a short time.
In the prior art, the furnace tubes of cracking furnaces commonly used in the petrochemical industry generally have the following structure:
(1) One or more ribs on the inner surface of the tube wall of one or more regions or all regions are arranged in the cracking furnace tube from the inlet end to the outlet end of the furnace tube along the axial direction of the furnace tube, and the ribs extend spirally on the inner surface of the tube wall along the axial direction of the furnace tube. For example, CN2144807Y discloses a reinforced heat transfer tube, which comprises a tube body, wherein single-blade rotating fins are fixed inside the tube body, although the fins can achieve the purpose of stirring fluid to reduce the thickness of the boundary layer as much as possible, as the service life of the tube increases, the coking on the inner surface of the tube will make the fins less effective, and the effect of reducing the boundary layer will also be reduced accordingly.
(2) The inner surface of the furnace tube is discretely provided with a plurality of fins which can also reduce the thickness of the boundary layer, but the fins also play a smaller role as the coking amount of the inner surface of the furnace tube increases.
(3) The cracking furnace tube is additionally provided with a twisted piece enhanced heat transfer tube, such as the heat transfer tube disclosed in CN104560111A, the twisted piece extends spirally along the axial direction of the heat transfer tube, and although the twisted piece enhanced heat transfer tube has better effects of enhancing heat transfer and inhibiting coking, the twisted piece enhanced heat transfer tube is cracked and fails because the twisted piece enhanced heat transfer tube is often subjected to the over-temperature condition of the furnace tube during the operation process and because the cracking furnace tube is inevitably subjected to carburization and other phenomena during the use process.
Therefore, the problem to be solved in the field is how to further slow down coking and carburization in the heat transfer pipe while ensuring the heat transfer effect of the heat transfer pipe, and to increase the temperature of the cracking material in a short time.
Disclosure of Invention
The invention aims to solve the problems that the inner wall of a heat transfer furnace tube in the prior art is easy to coke and carburize and has poor heat transfer effect, and provides a heat conduction furnace tube, a preparation method and application thereof in a cracking furnace.
In order to achieve the above object, a first aspect of the present invention provides a heat conducting furnace tube, which includes a furnace tube main body, wherein a plurality of groups of heat conducting members are arranged on an inner side wall of the furnace tube main body along a length direction of the furnace tube main body from a feeding port; the group of heat conducting components consists of a plurality of first heat conducting pieces and a second heat conducting piece, the first heat conducting pieces surround a circle along the cross section of the inner side wall of the furnace tube main body and protrude towards the inside of the furnace tube main body, and the second heat conducting pieces are spirally arranged along the axial direction of the furnace tube main body.
A second aspect of the present invention provides a method for manufacturing the heat conducting furnace tube of the first aspect, including heating the heat conducting furnace tube in an atmosphere with a low oxygen partial pressure to form a heat conducting layer on the surface of the heat conducting furnace tube.
In a third aspect, the invention provides a use of the heat conducting furnace tube of the first aspect in a cracking furnace.
The invention provides a cracking furnace radiation section furnace tube in a fourth aspect, which comprises the heat conducting furnace tube in the first aspect.
The heat-conducting furnace tube prepared by the invention is matched with the coating thermal barrier coating through the heat-conducting component, so that the heat transfer performance of the heat-conducting furnace tube can be effectively improved, the heat-conducting furnace tube can reach the high temperature required by the cracking reaction in a short time, the coking amount in the heat-conducting furnace tube prepared by the invention is greatly reduced, and the service life of the heat-conducting furnace tube is prolonged; and the carburization phenomenon of the heat conduction furnace tube can be reduced.
Drawings
Fig. 1 is a schematic structural view of a heat conductive member according to the present invention;
FIG. 2 is a schematic structural diagram of a heat transfer furnace tube in example 1;
FIG. 3 is a schematic view showing the structure of a type 1-1 furnace tube for a cracking furnace in example 2;
FIG. 4 is a schematic view showing the structure of a type 2-1 furnace tube for a cracking furnace in example 3.
Wherein, 1-the first heat conducting piece, 2-the second heat conducting piece, 3-the heat conducting furnace tube, 4-the first pass furnace tube, and 5-the second pass furnace tube.
Detailed Description
The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
The first aspect of the invention provides a heat-conducting furnace tube, wherein the heat-conducting furnace tube 3 comprises a furnace tube main body, and a plurality of groups of heat-conducting components are arranged on the inner side wall of the furnace tube main body from a feeding hole along the length direction of the furnace tube main body; the group of heat conducting components consists of a plurality of first heat conducting pieces 1 and a second heat conducting piece 2, the first heat conducting pieces 1 are formed by surrounding a circle along the cross section of the inner side wall of the furnace tube main body and protruding towards the inside of the furnace tube main body, and the second heat conducting pieces 2 are spirally arranged along the axial direction of the furnace tube main body.
According to the invention, the heat conduction member formed by the first heat conduction piece 1 and the second heat conduction piece 2 is arranged in the furnace tube main body, so that the tangential speed of fluid is improved, the boundary layer near the wall surface of the furnace tube is damaged, the heat transfer effect is improved, the coking phenomenon on the inner wall of the furnace tube is reduced, and the decoking period and the service life of the furnace tube are effectively prolonged. In the invention, the heat conduction components are arranged at the feed inlet of the heat conduction furnace tube, a plurality of groups of heat conduction components are arranged from the feed inlet, and the heat conduction components are arranged in a mode that the first heat conduction piece is close to the feed inlet and the second heat conduction piece is close to the discharge outlet.
The heat conducting furnace tube 3 can be a nickel-chromium furnace tube, and the composition of the nickel-chromium furnace tube comprises Cr, ni, fe, mn, C and at least one element selected from Al, zr, nb and Mo.
In order to further improve the heat transfer performance of the heat conduction furnace tube and reduce the coking phenomenon of the inner wall of the heat conduction furnace tube, the inner wall of the heat conduction furnace tube 3 is coated with a thermal barrier coating. Preferably, the second heat-conducting member is disposed at an interval in a portion of the heat-conducting furnace where the heat-conducting member is not disposed. That is, in the invention, the heat conducting furnace tube is provided with a plurality of groups of heat conducting components and second heat conducting pieces arranged at intervals in sequence from the feeding hole, and the inner wall of the heat conducting furnace tube is coated with a thermal barrier coating.
Further preferably, the thermal barrier coating comprises a thermally conductive layer comprising Cr 30-40 wt%, ni 2.5-6 wt%, fe 3-9 wt%, mn 8-13 wt%, C0-0.5 wt%, O35-40 wt%, and at least one element selected from Al, zr, nb, and Mo 1.5-20 wt%, based on the total amount of the thermally conductive layer.
In the invention, the heat conduction layer is arranged in the heat conduction furnace tube, and the heat conduction layer and the heat conduction component are matched with each other, so that the heat transfer performance and the wear resistance of the heat conduction furnace tube can be effectively improved, the coking phenomenon of the inner wall of the heat conduction furnace tube can be effectively inhibited, the anti-permeability performance of the heat conduction furnace tube is improved, the decoking period of the heat conduction furnace tube is prolonged, and the service life of the heat conduction furnace tube is prolonged.
Preferably, the thickness of the heat conducting layer is 0.1-5 μm. The heat conduction layer is within the thickness range, the coking amount of the heat conduction furnace tube can be effectively reduced, and the heat transfer performance of the heat conduction furnace tube cannot be influenced.
Preferably, the inner side of the heat conducting furnace tube 3 further comprises a strengthening coating positioned above the heat conducting layer, and the strengthening coating comprises SiO in percentage by weight based on the total amount of the strengthening coating 2 45-80% by weight, K 2 10-25% by weight of O, al 2 O 3 0-10 wt%, mgO 0-10 wt%, znO0-20 wt%, co 3 O 4 0-5 wt%, na 2 0 to 10 weight percent of O.
According to the invention, the reinforcing coating, the heat conduction layer and the heat conduction member arranged on the inner wall of the heat conduction furnace tube are matched with each other, so that the coking phenomenon of the inner wall of the heat conduction furnace tube can be further inhibited, and the service life of the furnace tube is prolonged.
Preferably, the thickness of the reinforcement coating is 5-10 μm. In the invention, the reinforcing coating is in the thickness range, so that the coking amount of the heat-conducting furnace tube can be effectively inhibited, the carburization phenomenon of the heat-conducting furnace tube is reduced, and the service life and the heat transfer efficiency of the heat-conducting furnace tube are improved. The reinforced coating and the heat conduction layer are mutually matched, so that the strong impact effect of air flow on the heating furnace tube in the decoking process can be effectively reduced, and the service life and the decoking period of the furnace tube can be further prolonged.
In order to further improve the heat transfer performance of the heat-conducting furnace tube, preferably, the extension length H of the multiple groups of heat-conducting members along the axial direction of the furnace tube main body satisfies: h is more than or equal to 1/4L and less than or equal to 1/3L; wherein L is the length of the furnace tube main body.
The extension length H of the heat conduction member along the axial direction of the furnace tube main body refers to the extension length of the heat conduction member consisting of the first heat conduction piece 1 and the second heat conduction piece 2 along the axial direction of the furnace tube main body. The heat conduction members can be arranged in multiple groups according to actual conditions, and if multiple groups of heat conduction members are arranged, H refers to the total axial extension length of the multiple groups of heat conduction members along the furnace tube main body.
The ethylene cracking reaction usually needs extremely short time to reach cracking high temperature, and the heat conducting components of the heat conducting furnace tube are arranged according to the structure, so that the heat conducting performance of the heat conducting furnace tube is further improved.
In order to further improve the heat transfer effect and simultaneously reduce the coking amount of the furnace tube, the diameter of an inner ring of the first heat conducting piece 1 is D, D satisfies D/D is more than or equal to 0.1 and less than or equal to 0.9, and D is the inner diameter of the main body of the furnace tube; preferably, 0.4. Ltoreq. D/D. Ltoreq.0.7.
In the invention, the inner diameters of the furnace tube main bodies are all diameters.
Preferably, the rotation angle of the spiral in the second heat-conducting member 2 is 90 ° to 1080 °, preferably 120 ° to 360 °; the extension length H1 of the second heat-conducting piece 2 along the axial direction of the furnace tube main body meets the following requirements: h1 is more than or equal to 2D and less than or equal to 8D, and D is the inner diameter of the furnace tube main body. The extension length H1 of the second heat conduction member 2 along the axial direction of the furnace tube main body is only the extension length of one second heat conduction member 2 in a spiral shape along the axial direction of the furnace tube main body. The ratio of the area of the middle opening of the second heat conduction member 2 to the cross section area of the furnace tube is 0.05-0.95, preferably 0.6-0.8.
In the invention, one group of heat conducting components consists of a plurality of parallel first heat conducting pieces 1 and a second heat conducting piece 2, and the ratio of the axial length of the heat conducting components to the inner diameter of the main body of the furnace tube is 8-12, preferably 9-10, and more preferably 10. The diameter D of the inner ring of the first heat conducting piece 1 is the diameter of the inner ring formed by the highest point of the first heat conducting piece 1 protruding out of the inner side of the furnace tube main body, and the axial distance between adjacent first heat conducting pieces 1 in one group of heat conducting components is 0.01D-2.5D, preferably 0.3D-1D, and more preferably 0.5D. The inner spiral of the second heat conduction member 2 can rotate clockwise or counterclockwise, and the spiral directions of the second heat conduction member 2 can be the same or opposite.
The first heat conducting piece 1 and the second heat conducting piece 2 are arranged according to the structure, and particularly under the condition that the first heat conducting piece 1 and the second heat conducting piece 2 are matched with the thermal barrier coating, the heat transfer effect of the heat conducting furnace tube can be greatly improved, the flow resistance of fluid in the heat conducting furnace tube is reduced, and the coking phenomenon of the inner wall of the heat conducting furnace tube is reduced.
In the invention, after the heat-conducting component and the second heat-conducting piece are arranged in the heat-conducting furnace tube under the actual use condition, the surface of the inner wall of the heat-conducting furnace tube is coated with the thermal barrier coating.
A second aspect of the present invention provides a method for manufacturing the heat conducting furnace tube of the first aspect, including heating the heat conducting furnace tube in an atmosphere with a low oxygen partial pressure to form a heat conducting layer on the surface of the heat conducting furnace tube.
In the process of preparing the heat conducting furnace tube, at least one metal selected from Al, zr, nb and Mo is added into the nichrome containing Cr, ni, fe, mn and C elements to prepare the tube according to the conventional preparation process of the cracking furnace tube (such as a centrifugal casting method, the temperature is 900-1000 ℃, the rotating speed is 1000-1300r/min, and the forming time is 3-4 h), and then the tube is heated in the low-oxygen partial-pressure environment to form a heat conducting layer on the surface of the tube. The heat conductive layer comprises 30-40 wt% of Cr, 2.5-6 wt% of Ni, 3-9 wt% of Fe, 8-13 wt% of Mn, 0-0.5 wt% of C, 35-40 wt% of O, and 1.5-20 wt% of at least one element selected from the group consisting of Al, zr, nb and Mo, based on the total weight of the heat conductive layer. The heat conduction layer is more convenient to form on the surface of the heat conduction furnace tube by adopting the method, the thermal interface between the heat conduction furnace tube and the heat conduction layer is reduced, and the heat conduction performance of the heat conduction furnace tube is improved.
In order to further improve the heat conductivity of the heat conducting furnace tube, the conditions of the low oxygen partial pressure atmosphere comprise: the gas providing the low oxygen partial pressure atmosphere comprises CO 2 、CO、H 2 And water vapor, the oxygen partial pressure is less than or equal to 10 -16 Pa; the conditions of the heat treatment include: the temperature of the heating treatment is 400-1100 ℃, preferably 800-1000 ℃; the time of the heat treatment is 5 to 200 hours, preferably 10 to 100 hours.
Preferably, the gas providing the low oxygen partial pressure atmosphere comprises CO 2 Gas mixture with CO, steam and gas of COMixture of bodies, H 2 And water vapor.
The heat conduction layer formed on the surface of the heat conduction furnace tube by the method has a stable structure and excellent heat transfer performance, and can reduce the coking amount of the inner wall of the heat conduction furnace tube.
In order to further improve the anti-coking performance of the heat conduction furnace tube and prolong the service life of the heat conduction furnace tube, the method also comprises the step of spraying a reinforcing coating on the surface of the heat conduction layer.
Preferably, the preparation method of the reinforced coating comprises the following steps: mixing the raw materials with water to form slurry, spraying the slurry on the surface of a heat-conducting layer, and sintering at the temperature of 1000-1100 ℃ to form a reinforced coating;
the reinforced coating comprises SiO in percentage by weight based on the total weight of the reinforced coating 2 45-80% by weight of K 2 10-25% by weight of O, al 2 O 3 0-10 wt%, mgO 0-10 wt%, znO0-20 wt%, co 3 O 4 0-5 wt%, na 2 0 to 10 weight percent of O.
The reinforced coating is arranged on the surface of the heat conducting layer according to the method, so that the interface thermal resistance between the heat conducting layer and the reinforced coating is reduced, the heat transfer performance of the heat conducting furnace tube is improved, and the coking amount of the inner wall of the heat conducting furnace tube is effectively reduced.
In a third aspect, the invention provides the use of the heat conducting furnace tube of the first aspect in a cracking furnace. Preferably used in the radiant coils of a cracking furnace.
The invention provides a cracking furnace radiation section furnace tube in a fourth aspect, which comprises the heat conducting furnace tube in the first aspect; preferably, the radiant section furnace tube of the cracking furnace is U-shaped, and the heat conduction furnace tube is arranged at two vertical parts of the radiant section furnace tube of the cracking furnace. Wherein, the radiant section furnace tube of the cracking furnace can be a 1-1 type furnace tube or a 2-1 type furnace tube. If the furnace tube is a 1-1 type furnace tube, as shown in fig. 3, the structure is U-shaped, and heat conducting furnace tubes are respectively disposed at two vertical portions of the U-shape. In the case of the 2-1 type furnace tube, as shown in FIG. 4, the structure is to add a single-pass furnace tube on the basis of the 1-1 type furnace tube, and the installation position of the heat conduction furnace tube is the same as that of the 1-1 type furnace tube.
The present invention will be described in detail below by way of examples.
In the following examples and comparative examples,
the heat transfer enhancement integration factor is defined as follows:
Figure BDA0002252190600000081
Figure BDA0002252190600000082
wherein, nu s Nu represents the Nussel number of the untreated smooth heat transfer furnace tube and the high-performance heat transfer furnace tube added with the inner member, f s F represents the resistance coefficient of the untreated smooth heat transfer furnace tube and the high-performance heat transfer furnace tube added with the inner member, d represents the inner diameter of the furnace tube, Δ p represents the pressure drop of the furnace tube, L represents the length of the furnace tube, ρ represents the density of fluid in the tube, and u represents the flow velocity of the fluid in the tube. In the above, the untreated smooth heat transfer furnace tube means that the heat conducting member, the heat conducting layer and the reinforcing coating are not arranged in the heat transfer furnace tube.
The untreated smooth heat transfer furnace tube means that no heat conduction component, heat conduction layer and reinforcing coating are arranged in the heat transfer furnace tube.
The variation of the heat transfer enhancement factor in the examples and comparative examples was determined by examining the heat transfer enhancement factor η 1 of the thermally conductive furnace tubes, the heat transfer enhancement factor η 0 of the untreated smooth heat transfer furnace tubes, and the variation of the heat transfer enhancement factor = (η 1- η 0)/η 0 × 100% in one operating cycle.
The variation of the coking amount is detected in one operation cycle, and the variation of the coking amount = (h 0-h 1)/h 0 × 100%, wherein the coking thickness h1 of the inner wall of the heat conduction furnace tube, the coking thickness h0 of the heat conduction furnace tube without the heat conduction component, the heat conduction layer and the reinforcing coating inside the heat conduction furnace tube are in the following embodiment and comparative example. Wherein, the operation periods of different heat conduction furnace tubes are not necessarily the same.
Example 1
This embodiment is used to provide a heat conducting furnace tube, as shown in fig. 2, which is a single-pass furnace tube in the radiant section furnace tube of the cracking furnace.
The heat-conducting furnace tube 3 comprises a furnace tube main body, wherein a plurality of groups of heat-conducting components are fixed on the inner side wall of the furnace tube main body, as shown in fig. 1, the part of the furnace tube main body, which is provided with the heat-conducting components, comprises a first heat-conducting piece 1 and a second heat-conducting piece 2 which are alternately fixed along the length direction of the furnace tube main body, and the part, which is not provided with the heat-conducting components, is fixed with the second heat-conducting piece 2 at intervals. The inner side wall of the heat conduction furnace tube 3 is coated with a thermal barrier coating, and the thermal barrier coating comprises a heat conduction layer and a reinforcing coating which are sequentially fixed from the inner wall of the heat conduction furnace tube.
The inner diameter D =25mm of the furnace tube main body, the length L =13m of the furnace tube main body, 16 groups of heat conduction components are evenly distributed along the axial direction of the furnace tube, and the extension length H =4m of the 16 groups of heat conduction components along the axial direction of the furnace tube main body. One set of heat conducting members comprises 15 first heat conducting members 1 and 1 second heat conducting member 2.
The first heat conducting piece 1 is a circular ring formed by surrounding a circle along the cross section of the inner wall of the furnace tube main body, the diameter d of the inner ring of the first heat conducting piece 1 is 12.5mm, and the axial distance between the adjacent first heat conducting pieces 1 is 12.5mm.
The second heat conducting pieces 2 are arranged in parallel along the axial direction of the furnace tube main body, the rotating angle of the second heat conducting pieces 2 along the spiral of the inner wall of the furnace tube main body is 180 degrees, and the two second heat conducting pieces 2 are spiral along the clockwise direction. The second heat conduction member 2 extends for a length H1=62.5mm along the length direction of the furnace tube main body, and the ratio of the middle opening area of the second heat conduction member 2 to the cross-sectional area of the furnace tube is 0.65.
And only the second heat conducting pieces 2 are arranged at intervals at the position where the axial length of the furnace tube main body is H =4m-13 m.
The preparation method of the heat conduction furnace tube 3 comprises the following steps:
(1) And carrying out low-oxygen partial pressure gas atmosphere treatment on the nickel-chromium furnace tube. The method comprises the steps of treating a nickel-chromium furnace tube containing Cr, ni, fe, mn, C and Zr for 3 hours at the temperature of 900 ℃ and the rotating speed of 1300r/min by adopting a centrifugal casting method, and then carrying out heat treatment under low oxygen partial pressure to form a heat conduction layer on the surface of the nickel-chromium furnace tube.
Low used in conditions of low oxygen partial pressureThe oxygen partial pressure gas is H 2 And water vapor, the water vapor accounts for 10% of the gas mixture by volume, the oxygen partial pressure is less than or equal to 10 -16 Pa. The heating temperature is 1000 ℃, the heating treatment time is 50h, and the heat conduction layer with the thickness of 3 μm is formed on the surface of the nickel-chromium furnace tube by the treatment of the method. Carrying out energy spectrum analysis on the heat conduction layer, and taking the total amount of the heat conduction layer as a reference, the heat conduction layer comprises the following components in percentage by weight: 40 wt% of Cr, 5 wt% of Ni, 5 wt% of Fe, 10 wt% of Mn, 0.5 wt% of C, 35 wt% of O, and 4.5 wt% of Zr.
(2) And coating a reinforced coating on the surface of the heat-conducting furnace tube 3. Mixing SiO 2 、K 2 O、Al 2 O 3 MgO and water are uniformly mixed to form slurry, the slurry is uniformly sprayed on the surface of the heat conduction layer and is sintered at the temperature of 1100 ℃ to form a reinforced coating with the thickness of 8 mu m, so that in the reinforced coating, the reinforced coating comprises the following components in percentage by weight based on the total amount of the reinforced coating: siO 2 2 75% by weight, K 2 O10 wt%, al 2 O 3 5 wt% and MgO 10 wt%.
The heat-conducting furnace tube 3 manufactured by the method is tested, the heat-conducting furnace tube 3 is used in a cracking furnace, the operation period is 35 days, and the heat-conducting furnace tube 3 can be normally used in the whole operation period. The coking amount of the heat-conducting furnace tube 3 is reduced by 30 percent, and the heat transfer enhancement comprehensive factor eta is improved by 26 percent.
Example 2
The present embodiment is used to provide a heat conducting furnace tube, as shown in fig. 3, which is a 1-1 type furnace tube in a radiant section furnace tube of a cracking furnace.
The 1-1 type furnace tube is U-shaped, the two vertical parts of the U-shaped furnace tube are heat conduction furnace tubes with the structure similar to that of the embodiment 1, and the lower ends of the two heat conduction furnace tubes are connected by a section of arc-shaped tube. The heat conducting furnace tube 3 in this embodiment includes a furnace tube main body, a plurality of sets of heat conducting members are fixed on an inner side wall of the furnace tube main body, a portion of the furnace tube main body where the heat conducting members are disposed includes a first heat conducting member 1 and a second heat conducting member 2 that are alternately fixed along a length direction of the furnace tube main body, and a portion of the furnace tube main body where the heat conducting members are not disposed fixes the second heat conducting member 2 at intervals. The inner side wall of the heat conduction furnace tube 3 is coated with a thermal barrier coating, and the thermal barrier coating comprises a heat conduction layer and a reinforcing coating which are sequentially fixed from the inner wall of the heat conduction furnace tube.
The inner diameter D =50mm of the furnace tube main body, the length L =13m of the furnace tube main body, 8 groups of heat conduction components are evenly distributed along the axial direction of the furnace tube, and the extension length H =4m of the 8 groups of heat conduction components along the axial direction of the furnace tube main body. One set of heat conducting members comprises 15 first heat conducting members 1 and 1 second heat conducting member 2.
The first heat conducting piece 1 is a circular ring formed by surrounding a circle along the cross section of the inner wall of the furnace tube main body, the diameter d of the inner ring of the first heat conducting piece 1 is 12.5mm, and the axial distance between every two adjacent first heat conducting pieces 1 is 25mm.
The second heat conducting pieces 2 are arranged in parallel along the axial direction of the furnace tube main body, the rotating angle of the second heat conducting pieces 2 along the spiral of the inner wall of the furnace tube main body is 180 degrees, and the two second heat conducting pieces 2 are spiral along the clockwise direction. The length H1=125mm of the second heat conduction member 2 extending along the length direction of the furnace tube main body, and the ratio of the area of the middle opening of the second heat conduction member 2 to the cross-sectional area of the furnace tube is 0.65.
And the second heat-conducting pieces 2 are only arranged at intervals at the position where the axial length of the furnace tube main body is H =4m-13 m.
The preparation method of the heat conduction furnace tube 3 comprises the following steps:
(1) And carrying out low-oxygen partial pressure gas atmosphere treatment on the nickel-chromium furnace tube. The method comprises the steps of treating a nickel-chromium furnace tube containing Cr, ni, fe, mn, C and Nb for 4 hours at the temperature of 1000 ℃ and the rotating speed of 1000r/min by adopting a centrifugal casting method, and then carrying out heat treatment under low oxygen partial pressure to form a heat conduction layer on the surface of the nickel-chromium furnace tube.
The low oxygen partial pressure gas used in the low oxygen partial pressure condition is H 2 And water vapor, the water vapor accounts for 10% of the gas mixture by volume, the oxygen partial pressure is less than or equal to 10 -16 Pa. The heating temperature is 800 ℃, the heating treatment time is 100h, and a heat conduction layer with the thickness of 5 mu m is formed on the surface of the nickel-chromium furnace tube after the treatment by the method. The heat conductive layer was analyzed by energy spectroscopy and comprised, in weight percent, 30% Cr, 3% Ni, 3% Fe, 8% Mn, 0.3% C, 38% O, and 17.7% Nb, based on the total weight of the heat conductive layer.
(2) And coating a reinforced coating on the surface of the heat-conducting furnace tube 3. Mixing SiO 2 、K 2 O、Al 2 O 3 、MgO、Co 3 O 4 、Na 2 Mixing O and water uniformly to form slurry, spraying the slurry on the surface of the heat-conducting layer uniformly, and sintering at 1000 ℃ to form a reinforcing coating with the thickness of 10 mu m, so that the reinforcing coating comprises the following components in percentage by weight based on the total amount of the reinforcing coating: siO 2 2 70% by weight, K 2 O10 wt%, al 2 O 3 5 wt%, mgO5 wt%, co 3 O 4 5% by weight and Na 2 O5 wt%.
The heat-conducting furnace tube 3 manufactured by the method is tested, the heat-conducting furnace tube 3 is used in a cracking furnace, the operation period is 110 days, and the heat-conducting furnace tube 3 can be normally used in the whole operation period. The coking amount of the heat-conducting furnace tube 3 is reduced by 28 percent, and the heat transfer enhancement comprehensive factor eta is improved by 25 percent.
Example 3
The present embodiment is used to provide a heat conducting furnace tube, as shown in fig. 4, which is a two-pass radiant-section cracking furnace tube, i.e. a 2-1 type furnace tube, and includes a first-pass furnace tube 4 and a second-pass furnace tube 5.
The 2-1 type furnace tube is formed by adding a one-way furnace tube on the basis of the 1-1 type furnace tube, and the one-way furnace tube is connected with the arc tube of the 1-1 type furnace tube through a section of arc tube. The arrangement positions of the heat conduction furnace tubes are the same as those in embodiment 2, and the heat conduction furnace tubes are both arranged at two vertical parts of the U-shaped structure. The heat conducting furnace tube 3 in this embodiment includes a furnace tube main body, a plurality of sets of heat conducting members are fixed on an inner side wall of the furnace tube main body, a portion of the furnace tube main body where the heat conducting members are disposed includes a first heat conducting member 1 and a second heat conducting member 2 that are alternately fixed along a length direction of the furnace tube main body, and a portion of the furnace tube main body where the heat conducting members are not disposed fixes the second heat conducting member 2 at intervals. The inner side wall of the heat conduction furnace tube 3 is coated with a thermal barrier coating, and the thermal barrier coating comprises a heat conduction layer and a reinforcing coating which are sequentially fixed from the inner wall of the heat conduction furnace tube.
The inner diameter D =50mm of the furnace tube main body, the length L =13m of the furnace tube main body, 8 groups of heat conduction components are evenly distributed along the axial direction of the furnace tube, and the extension length H =4m of the 8 groups of heat conduction components along the axial direction of the furnace tube main body. One set of heat conducting members comprises 15 first heat conducting members 1 and 1 second heat conducting member 2.
The first heat conducting piece 1 is a circular ring formed by surrounding a circle along the cross section of the inner wall of the furnace tube main body, the diameter d of the inner ring of the first heat conducting piece 1 is 12.5mm, and the axial distance between every two adjacent first heat conducting pieces 1 is 25mm.
The second heat conducting pieces 2 are arranged in parallel along the axial direction of the furnace tube main body, the rotating angle of the second heat conducting pieces 2 along the spiral of the inner wall of the furnace tube main body is 180 degrees, and the two second heat conducting pieces 2 are spiral along the clockwise direction. The second heat conduction member 2 extends for a length H1=125mm along the length direction of the furnace tube main body, and the ratio of the middle opening area of the second heat conduction member 2 to the cross-sectional area of the furnace tube is 0.65.
And only the second heat conducting pieces 2 are arranged at intervals at the position where the axial length of the furnace tube main body is H =4m-13m and the position of the second-pass furnace tube 5.
The preparation method of the heat conduction furnace tube 3 comprises the following steps:
(1) And carrying out low-oxygen partial pressure gas atmosphere treatment on the nickel-chromium furnace tube. The method comprises the steps of treating a nickel-chromium furnace tube containing Cr, ni, fe, mn, C and Mo for 3 hours at 950 ℃ and 1200r/min by adopting a centrifugal casting method, and then carrying out heat treatment under low oxygen partial pressure to form a heat conduction layer on the surface of the nickel-chromium furnace tube.
The low oxygen partial pressure gas used in the low oxygen partial pressure condition is CO 2 And CO, the CO being 20% by volume of the gas mixture, the oxygen partial pressure being less than or equal to 10 -16 Pa. The heating temperature is 800 ℃, the heating treatment time is 200h, and the heat conduction layer with the thickness of 1 mu m is formed on the surface of the nickel-chromium furnace tube after the treatment by the method. Carrying out energy spectrum analysis on the heat conduction layer, and taking the total amount of the heat conduction layer as a reference, wherein the heat conduction layer comprises the following components in percentage by weight: 30% by weight of Cr, 4% by weight of Ni, 6% by weight of Fe, 9.5% by weight of Mn, 0.5% by weight of C, 40% by weight of O, and 10% by weight of Mo.
(2) And coating a reinforced coating on the surface of the heat-conducting furnace tube 3. Mixing SiO 2 、K 2 O、Al 2 O 3 MgO, znO and water are evenly mixed to form slurry, the slurry is evenly sprayed on the surface of the heat conduction layer and is sintered at the temperature of 1100 ℃ to form the material with the thickness of 5μ m, such that the reinforcement coating comprises, in weight percent based on the total amount of reinforcement coating: siO 2 2 70% by weight, K 2 O10 wt%, al 2 O 3 7 wt%, mgO5 wt% and ZnO8 wt%.
The heat-conducting furnace tube 3 manufactured by the method is tested, the heat-conducting furnace tube 3 is used in a cracking furnace, the operation period is 110 days, and the heat-conducting furnace tube 3 can be normally used in the whole operation period. The coking amount of the heat-conducting furnace tube 3 is reduced by 28 percent, and the heat transfer strengthening comprehensive factor eta is improved by 20 percent.
Example 4
This embodiment provides a heat conduction furnace tube, which has the same structure as the heat conduction furnace tube in embodiment 1, and the difference is that: the heat conducting furnace tube is not provided with a thermal barrier coating. The heat-conducting furnace tube is used in a cracking furnace, the operation period is 30 days, and the heat-conducting furnace tube can be normally used in the whole operation period. The heat transfer strengthening comprehensive factor eta of the heat conduction furnace tube 3 is improved by 23 percent.
Comparative example 1
This comparative example provides a single pass heat transfer tube having the same structure as the heat transfer tubes of example 1, except that: the heat conducting component is not arranged in the single-pass heat transfer pipe, and the thermal barrier coating is not arranged in the single-pass heat transfer pipe. The single pass heat transfer tube was used in a cracking furnace with a 15 day operating cycle. After 15 days, the coke in the coke oven is serious, and the coke oven cannot be normally used and needs to be cleaned.
Comparative example 2
This comparative example provides a 1-1 type pyrolysis furnace heat transfer tube, the same in construction as the heat transfer tube of example 2, except that: the heat transfer member is not provided inside the type 1-1 heat transfer tube, and the thermal barrier coating is not provided. The 1-1 type heat transfer tube was used in a cracking furnace and operated for a period of 60 days. After more than 60 days, the coke inside the coke oven is serious, and the coke oven cannot be normally used, so that the coke oven needs to be cleaned.
Comparative example 3
This comparative example provides a two-pass heat transfer tube having the same structure as the heat transfer tube of example 1, except that: the heat conducting component is not arranged in the two-stroke heat transfer pipe, and the thermal barrier coating is not arranged in the two-stroke heat transfer pipe. The two-pass heat transfer tube is used for a cracking furnace, and the operation period is 60 days. After more than 60 days, the coke inside the coke oven is serious, and the coke oven cannot be normally used, so that the coke oven needs to be cleaned.
Comparative example 4
This comparative example provides a single pass heat transfer tube having the same structure as the heat transfer tubes of example 1, except that: the heat conducting member inside the single pass heat transfer tube includes only the first heat conducting member. The single pass heat transfer tube was used in a cracking furnace with a 28 day operating cycle. After 28 days, the coke inside the coke oven is serious, and the coke oven cannot be normally used, so that the coke oven needs to be cleaned. The heat transfer strengthening comprehensive factor eta is improved by 9 percent.
Comparative example 5
This comparative example provides a single pass heat transfer tube having the same structure as the heat transfer tubes of example 1, except that: the heat conducting member inside the single pass heat transfer tube includes only the second heat conducting member. The single pass heat transfer tube was used in a cracking furnace for an operating period of 30 days. After more than 30 days, the coke inside the coke oven is serious, and the coke oven cannot be normally used, so that the coke oven needs to be cleaned. The heat transfer enhancement comprehensive factor eta is improved by 12 percent.
The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims (22)

1. A heat conduction furnace tube is characterized in that: the heat conduction furnace tube comprises a furnace tube main body, and a plurality of groups of heat conduction components are arranged on the inner side wall of the furnace tube main body from the feed inlet along the length direction of the furnace tube main body; the group of heat conduction components consists of a plurality of first heat conduction pieces and a second heat conduction piece, the first heat conduction pieces surround the cross section of the inner side wall of the furnace tube main body for one circle and protrude inwards the furnace tube main body, and the second heat conduction pieces are spirally arranged along the axial direction of the furnace tube main body;
the extension length H of the multiple groups of heat conduction components along the axial direction of the furnace tube main body meets the following requirements: h is more than or equal to 1/4L and less than or equal to 1/3L; wherein L is the length of the furnace tube main body;
the diameter of the inner ring of the first heat conducting piece is D, D satisfies D/D is more than or equal to 0.1 and less than or equal to 0.9, and D is the inner diameter of the furnace tube main body;
the rotation angle of the spiral in the second heat conducting piece is 90-1080 degrees; the extension length H1 of the second heat-conducting piece along the axial direction of the furnace tube main body meets the following requirements: h1 is more than or equal to 2D and less than or equal to 8D, and D is the inner diameter of the furnace tube main body; the ratio of the area of the middle opening of the second heat conduction member to the cross section area of the furnace tube is 0.05-0.95.
2. The thermally conductive furnace tube of claim 1, wherein an inner wall of the thermally conductive furnace tube is coated with a thermal barrier coating.
3. The heat conducting furnace tube of claim 1 or 2, wherein the portion of the heat conducting furnace tube where no heat conducting member is disposed is provided with second heat conducting members at intervals.
4. The thermally conductive furnace tube of claim 2, wherein the thermal barrier coating comprises a thermally conductive layer comprising 30-40 wt.% Cr, 2.5-6 wt.% Ni, 3-9 wt.% Fe, 8-13 wt.% Mn, 0-0.5 wt.% C, 35-40 wt.% O, and 1.5-20 wt.% of at least one element selected from the group consisting of Al, zr, nb, and Mo, based on the total weight of the thermally conductive layer.
5. The heat conducting furnace tube according to claim 4, wherein the heat conducting layer has a thickness of 0.1-5 μm.
6. The heat conductive furnace tube of claim 4 or 5, wherein the inner side of the heat conductive furnace tube further comprises a reinforcement coating over the heat conductive layer, the reinforcement coating comprising SiO in weight percent based on the total amount of reinforcement coating 2 45-80% by weight, K 2 10-25% by weight of O, al 2 O 3 0-10 wt%, mgO 0-10 wt%, znO0-20 wt%, co 3 O 4 0-5 wt%, na 2 0 to 10 weight percent of O.
7. The heat conducting furnace tube according to claim 6, wherein the reinforcement coating has a thickness of 5-10 μm.
8. The heat conduction furnace tube according to claim 1, wherein D satisfies D/D0.4. Ltoreq.0.7.
9. The thermally conductive furnace tube of claim 1, wherein the angle of rotation of the spiral in the second thermally conductive member is between 120 ° and 360 °.
10. The heat conducting furnace tube of claim 1, wherein the ratio of the area of the second heat conducting member intermediate opening to the cross-sectional area of the furnace tube is 0.6-0.8.
11. The thermally conductive furnace tube of any of claims 1-2, 4-5, and 7, wherein the axial distance between adjacent first thermally conductive members in a set of thermally conductive members is between 0.01D and 2.5D.
12. The thermally conductive furnace tube of claim 11, wherein the axial distance between adjacent first thermally conductive members in a set of thermally conductive members is between 0.3D and 1.0D.
13. The heat conducting furnace tube of any one of claims 1-2, 4-5, and 7, wherein the ratio of the axial length of one set of heat conducting members to the inner diameter of the main body of the furnace tube is 8-12.
14. The thermally conductive furnace tube of claim 13, wherein the ratio of the axial length of the set of thermally conductive members to the inner diameter of the furnace tube body is between 9 and 10.
15. A method for manufacturing the heat conducting furnace tube according to any one of claims 1 to 14, comprising heating the heat conducting furnace tube under an atmosphere of low oxygen partial pressure to form a heat conducting layer on the surface.
16. The method of claim 15, wherein the conditions of the low oxygen partial pressure atmosphere include: the gas providing the low oxygen partial pressure atmosphere comprises CO 2 、CO、H 2 And water vapor, the oxygen partial pressure is less than or equal to 10 -16 Pa; the conditions of the heat treatment include: the temperature of the heating treatment is 400-1100 ℃; the time of the heat treatment is 5 to 200 hours.
17. The production method according to claim 16, wherein the temperature of the heat treatment is 800 to 1000 ℃ and the time of the heat treatment is 10 to 100 hours.
18. The method of claim 15, further comprising spraying an enhancement coating on the surface of the thermally conductive layer.
19. The method of producing of claim 18, wherein the method of producing the reinforcement coating comprises: mixing the raw materials with water to form slurry, spraying the slurry on the surface of a heat-conducting layer, and sintering at the temperature of 1000-1100 ℃ to form a reinforced coating;
the reinforced coating comprises SiO in percentage by weight based on the total amount of the reinforced coating 2 45-80% by weight, K 2 10-25% by weight of O, al 2 O 3 0-10 wt%, mgO 0-10 wt%, znO0-20 wt%, co 3 O 4 0-5 wt%, na 2 0 to 10 weight percent of O.
20. Use of the heat conducting furnace tube of any one of claims 1-14 in a pyrolysis furnace.
21. A radiant coils for a pyrolysis furnace comprising the thermally conductive coils of any one of claims 1-14.
22. The pyrolysis furnace radiant coils of claim 21, wherein the pyrolysis furnace radiant coils are U-shaped, and the heat conducting coils are disposed at two vertical portions of the pyrolysis furnace radiant coils.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102399570A (en) * 2010-09-16 2012-04-04 中国石油化工股份有限公司 Method for restraining coking and carburization of radiant tube of ethylene cracking furnace,
CN106554799A (en) * 2015-09-29 2017-04-05 中国石油化工股份有限公司 Pyrolysis furnace nichrome boiler tube and preparation method thereof
CN106554797A (en) * 2015-09-29 2017-04-05 中国石油化工股份有限公司 A kind of processing method of pyrolysis furnace with nichrome boiler tube
CN107603662A (en) * 2016-07-11 2018-01-19 中国石油化工股份有限公司 Processing method, thus obtained pyrolysis furnace nichrome boiler tube and the method for producing ethene of pyrolysis furnace nichrome boiler tube

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102399570A (en) * 2010-09-16 2012-04-04 中国石油化工股份有限公司 Method for restraining coking and carburization of radiant tube of ethylene cracking furnace,
CN106554799A (en) * 2015-09-29 2017-04-05 中国石油化工股份有限公司 Pyrolysis furnace nichrome boiler tube and preparation method thereof
CN106554797A (en) * 2015-09-29 2017-04-05 中国石油化工股份有限公司 A kind of processing method of pyrolysis furnace with nichrome boiler tube
CN107603662A (en) * 2016-07-11 2018-01-19 中国石油化工股份有限公司 Processing method, thus obtained pyrolysis furnace nichrome boiler tube and the method for producing ethene of pyrolysis furnace nichrome boiler tube

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