Method for heating fluid and tube arrangement of fluid heating furnace for method
The tube array with conductive materials and strategic electrical insulator placement in the steam cracking furnace addresses the energy consumption and emissions issues by enabling efficient Joule heating, reducing the reliance on gas combustion.
Patent Information
- Application Number
- JP2024203565
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-12-13
- Filing Date
- 2024-11-22
- Publication Date
- 2025-06-26
AI Technical Summary
The steam cracking process for producing alkenes consumes a large amount of energy and results in significant CO2 emissions due to the high heating temperatures required, typically between 800°C to 1000°C, achieved through gas combustion.
A tube array for a fluid heating furnace is designed with conductive materials allowing electric current to flow along the tube walls, enabling direct Joule heating of the fluid. This setup includes a bundle of tubes with varying diameters arranged in a circular pattern and uses electrical insulators to manage current flow, reducing energy consumption and emissions.
The proposed solution efficiently heats the fluid by reducing the need for high-energy gas combustion, thereby lowering energy consumption and CO2 emissions while maintaining the high temperatures necessary for the steam cracking process.
Smart Images
Figure 2025096177000001_ABST
Abstract
Description
Technical Field
[0001] The present invention generally relates to the heating of fluids (particularly steam cracking) in tube arrays. In particular, the present invention relates to a tube array for a fluid heating furnace, a fluid heating furnace including such a tube array, and a fluid heating method using such a fluid heating furnace.
Background Art
[0002] Steam cracking is a petrochemical process that converts light alkane molecules (such as ethane) or mainly naphtha into alkenes. Alkenes are generally known as olefins and are the basis of many industries in various fields (such as cosmetics, pharmaceuticals, aviation, etc.), and in particular, the basis of plastic production.
[0003] In the steam cracking process, hydrocarbons are pyrolyzed at very high temperatures in the presence of steam in a steam cracking furnace.
[0004] Typically, the cracking furnace includes tubes in which the cracking reaction occurs and gas burners disposed on both sides of the tubes.
[0005] A mixture of hydrocarbon and steam circulates through the tubes and passes through the region heated by the burners.
[0006] Therefore, the heating process is based on the combustion of gas. Since the heating temperature of the mixture generally requires 800°C to 1000°C, steam cracking consumes a large amount of energy and increases the CO2 emissions.
[0007] Therefore, the present invention aims to overcome these drawbacks by providing a heating means for the steam cracking process that reduces the release of pollutants.
Summary of the Invention
[0008] One object of the present invention is a tube array for a fluid heating furnace, the tube array including at least one tube containing a conductive material that enables an electric current to flow along the wall of the tube.
[0009] In the present invention, the term "conductive material" refers to a material having a conductivity of 10 4 Ω -1 .m -1 or more.
[0010] Preferably, the at least one tube includes a plurality of juxtaposed portions of the same tube and / or several tubes arranged in at least one bundle of dense tube portions.
[0011] In one embodiment, the cross-section of the tube portion of the bundle can be arranged in a circular pattern.
[0012] Preferably, the at least one tube includes at least one pin, more preferably a plurality of pins, and is, for example, a U-shaped tube, a W-shaped tube or a serpentine-shaped tube.
[0013] It is advantageous for the tube array to include at least one electrical insulator IS1 arranged between the at least one tube and the rest of the tube array to limit the flow of electric current from the at least one tube to the rest of the tube array.
[0014] Advantageously, the tube array includes a current inlet for supplying an electric current along the walls of a plurality of tubes and a current outlet.
[0015] Preferably, the current inlet is located downstream of the electrical insulator IS1, where "downstream" is considered in relation to the fluid path along the plurality of tubes.
[0016] Preferably, the current outlet is located upstream of the electrical insulator IS1, where the term "upstream" is considered in relation to the fluid path along the plurality of tubes.
[0017] Including at least one element for positioning and holding at least one tube of the steam cracking furnace, it is advantageous that the element for positioning and holding includes at least one electrical insulator IS1.
[0018] It is advantageous that the at least one electrical insulator IS1 includes an electrical insulating material, a ferromagnetic material, a coil, a solenoid, or a combination thereof.
[0019] As an example, the at least one electrical insulator IS1 can include a toroid made of a ferromagnetic material.
[0020] In one embodiment, the tube arrangement can include a plurality of electrical insulators IS2 arranged to form a meandering path for electricity along the tube arrangement.
[0021] For example, the at least one tube includes at least first and second horizontal tubes and a plurality of vertical tubes fluidly connecting the first and second horizontal tubes, and the tube arrangement includes a plurality of electrical insulators IS2 arranged on a part of the first and second horizontal tubes such that a meandering path for electricity along the tube arrangement is formed.
[0022] It is advantageous that the plurality of electrical insulators IS2 includes a ferromagnetic material, a coil, a solenoid, or a combination thereof.
[0023] As an example, the plurality of electrical insulators IS2 can include a toroid made of a ferromagnetic material.
[0024] In one embodiment, the at least one tube includes a plurality of tubes, and the tube arrangement includes at least one inductor arranged around two adjacent parallel tubes of the plurality of tubes of the tube arrangement, the at least one inductor forming a magnetic field opposite to the current so as to form a meandering path for electricity along the tube arrangement.
[0025] For example, the at least one tube includes at least two horizontal tubes and a plurality of vertical tubes fluidly connecting the two horizontal tubes, and the tube arrangement includes at least one inductor disposed around two adjacent parallel tubes of the plurality of vertical tubes, the at least one inductor for forming a magnetic field opposite to the current.
[0026] In another embodiment, the at least one tube includes an odd number of pairs of a first tube and a second tube, the first tube of each pair including a first end and a second end, the second tube of each pair including a first end and a second end, the first ends of the first and second tubes of each pair being fluidly and electrically connected, the second ends of the first and second tubes of the pair being fluidly and electrically connected, the first and second ends of the first and second tubes of each pair being connected to ground, a current inlet I1 being disposed at a central portion between the ground of the first end and the ground of the second end in the first tube of each pair, a current outlet I2 being disposed at a central portion between the ground of the first end and the ground of the second end in the second tube of each pair.
[0027] As an example, the at least one tube can include at least three pairs of a first tube and a second tube.
[0028] Another object of the present invention is a furnace for heating a fluid, including the at least one tube arrangement described above.
[0029] Also, the present invention relates to a method including the steps of introducing a fluid into at least one tube of the fluid heating furnace described above, and heating the fluid by injecting a current along the wall of the at least one tube.
[0030] The cross-section of the tube portion of the bundle is arranged in a circular pattern, preferably with the hottest tube arranged at the center of the circular pattern and the coldest tube arranged around it, which is advantageous.
[0031] The method of heating the fluid advantageously includes increasing the frequency of the current flowing through the wall of the at least one tube so that the skin effect is obtained.
[0032] Preferably, the method of heating the fluid includes increasing the frequency of the current flowing through the walls of two adjacent parallel tubes in the tube arrangement so that the proximity effect can be utilized.
[0033] The method of heating the fluid advantageously includes increasing the inductance of at least one electrical insulator IS1 arranged between the at least one tube of the tube arrangement and the rest of the tube arrangement to limit the current flowing from the at least one tube to the rest of the tube arrangement.
[0034] In one embodiment, the fluid introduced into the at least one tube of the fluid heating furnace is a mixture of hydrocarbon and steam for steam reforming.
[0035] Other advantages and features of the present invention will become apparent from the detailed description of embodiments of the present invention, which are non-limiting examples illustrated in the accompanying drawings. The embodiments are non-limiting examples and are shown in the drawings.
Brief Description of the Drawings
[0036]
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6A
Figure 6B
DETAILED DESCRIPTION OF THE INVENTION
[0037] Hereinafter, the term "at least one" used in this specification is equivalent to the term "one or more".
[0038] Furthermore, elements common to different embodiments are denoted by the same reference numerals.
[0039] FIG. 1 shows a steam cracking furnace for steam cracking hydrocarbons in the presence of steam. This steam cracking furnace includes a pipe array 2, and in the pipe array, a steam cracking reaction is carried out.
[0040] In the illustrated example, the pipe array 2 includes a plurality of pipes.
[0041] The plurality of pipes shown in FIG. 1 include a conductive material through which an electric current can flow along the walls of the plurality of pipes.
[0042] In another embodiment, the pipe array 2 may be composed of a single pipe.
[0043] For example, a single pipe or a plurality of pipes of the pipe array can be manufactured from 310 stainless steels.
[0044] Due to the electrical conduction characteristics of the plurality of pipes, the mixture circulating through the plurality of pipes can be directly heated by the Joule effect.
[0045] The plurality of pipes of the pipe array 2 can include at least two horizontal pipes and a plurality of vertical pipes connecting the at least two horizontal pipes.
[0046] In the example shown in FIG. 1, the plurality of tubes can include first and second horizontal tubes 3a, 3b, and first, second, third, fourth, and fifth vertical tubes 4a, 4b, 4c, 4d, and 4e that fluidly connect the first and second horizontal tubes 3a, 3b.
[0047] The tube array 2 is composed of an inlet portion 5 for supplying a mixture of hydrocarbon and steam to the tube array 2 and an outlet portion 6 for discharging the mixture obtained by steam reforming from the tube array 2.
[0048] The tube array 2 includes a current inlet portion I1 for supplying an electric current along the walls of a plurality of tubes (including the first and second horizontal tubes 3a and 3b and the first, second, third, fourth, and fifth vertical tubes 4a, 4b, 4c, 4d, and 4e).
[0049] The tube array 2 also includes a current outlet portion I2.
[0050] The tube array 2 advantageously includes at least one element 7 for positioning and holding the plurality of tubes of the steam reformer 1.
[0051] In the example shown in FIG. 1, the tube array 2 includes four elements 7 for positioning and holding the plurality of tubes of the steam reformer 1.
[0052] To prevent damage to the steam reformer, the tube array 2 can include one or more electrical insulators IS1 8.
[0053] Preferably, the current inlet portion I1 is located downstream of the electrical insulator IS1 8. "Downstream" is considered in relation to the fluid path along the plurality of tubes.
[0054] Preferably, the current outlet portion I2 is located upstream of the electrical insulator IS1 8. The term "upstream" is considered in relation to the fluid path along the plurality of tubes.
[0055] The electrical insulator IS1 8 prevents damage to the steam reformer 1.
[0056] Preferably, the tube array 2 advantageously includes at least one electrical insulator IS1 8 disposed between the plurality of tubes and the remainder of the tube array 2. This is to limit the flow of current from the plurality of tubes to the remainder of the tube array 2.
[0057] The steam reformer 1 shown in FIG. 1 also includes four electrical insulators IS1 8, and each electrical insulator IS1 8 is disposed in one of the four elements 7 for positioning and holding.
[0058] In one embodiment, the electrical insulator IS1 8 includes an electrically insulating material, and the electrically insulating material can be disposed in an element 7 (such as a ceramic material) for positioning and holding.
[0059] In the present invention, the term "electrical insulator" refers to an element having an electrical conductivity of 10 4 Ω -1 .m -1 as follows.
[0060] The electrical insulator IS1 8 or the plurality of electrical insulators IS1 8 advantageously has an electrically insulating material, a ferromagnetic material, a coil, a solenoid, or a combination thereof that increases the value of the inductance to reduce or stop the flow of current from the plurality of tubes of the tube array 2 to the remainder of the tube array 2 and the remainder of the steam reformer 1.
[0061] As an example, at least one of the plurality of electrical insulators IS1 8 can include a toroid made of a ferromagnetic material. The toroid made of a ferromagnetic material can be disposed around the element 7 for positioning and holding.
[0062] As an example, the electrical insulator IS1 8 can include an electrically insulating material such as a ceramic material.
[0063] The electrical insulator IS1 8 located upstream of the current inlet I1 must allow the fluid to flow into and through the tube array 2.
[0064] Furthermore, the electrical insulator IS1 8 located downstream of the current outlet I2 must allow the fluid to exit from the pipe array 2.
[0065] Therefore, the electrical insulator IS1 8 located upstream of the current inlet I1 and the electrical insulator IS1 8 located downstream of the current outlet I2 can be, for example, toroids made of ferromagnetic materials.
[0066] Referring now to FIG. 2, the plurality of pipes of the pipe array 2 can include a plurality of juxtaposed portions of several pipes arranged in at least one bundle of the dense pipe portions.
[0067] In another embodiment, the plurality of pipes of the pipe array 2 can include a plurality of juxtaposed portions of the same pipe arranged in at least one bundle of the dense pipe portions.
[0068] In another embodiment, the plurality of pipes of the pipe array 2 can include a plurality of juxtaposed portions of the same pipe and a plurality of juxtaposed portions of several pipes arranged in at least one bundle 9 of the dense pipe portions.
[0069] The bundle 9 of the dense pipe portions minimizes heat loss and promotes heat transfer in order to enhance the heating of the mixture of hydrocarbon and steam circulating in the plurality of pipes of the pipe array 2.
[0070] Also, the plurality of pipes of the pipe array 2 can include pipes of various diameters.
[0071] In the example of FIG. 2, the pipe array 2 includes four bundles 9 of the dense pipe portions.
[0072] Furthermore, the cross-section of the pipe portions of the bundle of the dense pipe portions can advantageously be arranged in a circular pattern.
[0073] The bundle of tube portions shown includes tubes of at least two different diameters. The tube 10 with the largest diameter is arranged at the center of the circular pattern, and the tube 11 with the smallest diameter is arranged around it.
[0074] Preferably, the hottest tube 10 is arranged at the center of the circular pattern, and the coldest tube 11 is arranged at the periphery of the circular pattern.
[0075] With this arrangement, heat loss is further minimized and heat transfer is further promoted. Heat is radiated from the hottest tube and captured by the coldest tube arranged around the hottest tube.
[0076] The steam reformer 1 advantageously includes an electric bar and a transformer to supply an electric current to the tube array 2.
[0077] To heat the steam reforming tube by the Joule effect, it is necessary to supply a large electric current, which means that a large electric conductor is required.
[0078] As an example, in the case of the tube array 2 including a single tube or a plurality of tubes with a diameter of 10 cm and a wall thickness of 2 cm, the electrical resistance is 4.10 - 4 Ω / m at 1100 K, which is particularly low. For a 10-meter-long tube, a current of 9 kA and a voltage of 40 V are required.
[0079] According to a certain feature, the electrical resistance of the single tube or the plurality of tubes of the tube array 2 can be increased.
[0080] The electrical resistance can be increased by changing the shape of the tube array 2.
[0081] In one embodiment, the electrical resistance can be increased by increasing the distance through which the current flows (thus, the length of the single tube or the plurality of tubes of the tube array 2).
[0082] In order to increase the length of a single tube or a plurality of tubes of the tube array 2, if there are a plurality of tubes, as shown in FIG. 3, it can be composed of at least one tube (for example, having a U-shape, a W-shape, or a serpentine shape) including at least one pin.
[0083] In the example shown in FIG. 3, the same reference numerals are assigned to the same parts, and the tube array 2 includes a single serpentine tube 12 having a serpentine shape and including six pins.
[0084] The presence of the pins makes it possible to increase the length of a single tube or a plurality of tubes. As a result, the electrical resistance of the current flowing along the wall of the tube increases.
[0085] By increasing the electrical resistance, the total current along the plurality of tube walls required for Joule heating can be reduced, and it becomes easy to supply current to the tubes of the tube array 2 and to connect and Joule heat the tubes. In fact, a large conductor is no longer necessary.
[0086] Furthermore, FIG. 4 shows an embodiment of the tube array 2. In this embodiment, the tube array 2 includes first and second horizontal tubes 13a and 13b, and first, second, third, fourth, and fifth vertical tubes 14a, 14b, 14c, 14d, and 14e that fluidly connect the first and second horizontal tubes 13a and 13b.
[0087] The tube array 2 also includes a current inlet I1 and a current outlet I2.
[0088] It is advantageous to arrange the current inlet I1 downstream of the electrical insulator IS1 8 and the current outlet I2 upstream of the electrical insulator IS1 8.
[0089] The first and second horizontal tubes 13a, 13b include an inlet 5 for a mixture of hydrocarbon and steam and an outlet 6 for the mixture obtained by steam reforming.
[0090] The tube array 2 advantageously also includes at least one element 7 for positioning and holding a plurality of horizontal and vertical tubes 13a, 13b, 14a, 14b, 14c, 14d, 14e in the steam cracking furnace 1.
[0091] The tube array 2 shown in FIG. 4 also includes a plurality of electrical insulators IS1 8 arranged on the element 7 for positioning and holding.
[0092] Furthermore, the tube array 2 includes a plurality of electrical insulators IS2 15 arranged on a part of the first and second horizontal tubes 13a, 13b so that an electrical meandering path along the tube array 2 is formed.
[0093] The electrical insulator IS2 15 advantageously includes an electrical insulating material, a ferromagnetic material, a coil, a solenoid, or a combination thereof.
[0094] As shown in the example of FIG. 4, the electrical insulator IS2 15 can include a toroid made of a ferromagnetic material.
[0095] As an alternative, the presence of the electrical insulator IS2 15 can lengthen the path of the current, thereby increasing the electrical resistance of the current flowing along the walls of the horizontal and vertical tubes 13a, 13b, 14a, 14b, 14c, 14d, 14e.
[0096] To lengthen the path of the current, the tube array 2 can alternatively include one inductor or a plurality of inductors 16 arranged around two adjacent parallel tubes among the plurality of tubes of the tube array 2. Each inductor 16 generates a magnetic field opposite to the current. The magnetic fields in two adjacent parallel tubes are combined, increasing the power consumption in each tube, and as a result, the current flows in a zigzag along the tube array 2.
[0097] As shown in FIG. 5, the tube array 2 includes first and second horizontal tubes 13a and 13b, and first, second, third, fourth, fifth, and sixth vertical tubes 14a, 14b, 14c, 14d, and 14e that fluidly connect the first and second horizontal tubes 13a and 13b.
[0098] The tube array 2 shown in FIG. 5 also includes five inductors 16. The first inductor 16 is disposed around the first and second vertical tubes 14a and 14b, the second inductor 16 is disposed around the second and third vertical tubes 14b and 14c, the third inductor 16 is disposed around the third and fourth vertical tubes 14c and 14d, the fourth inductor 16 is disposed around the fourth and fifth vertical tubes 14d and 14e, and the sixth inductor 16 is disposed around the fifth and sixth vertical tubes 14e and 14f.
[0099] In the illustrated example, the inductor 16 is a ferromagnetic toroid. The magnetic fields on both sides of each inductor 16 are respectively formed in one of the two adjacent parallel vertical tubes of the two adjacent parallel vertical tubes. The magnetic fields on both sides of each inductor 16 cancel out the current, limit the flow of the current, and cause the current to flow in a zigzag along the tube array 2, so that the path of the current becomes longer.
[0100] Furthermore, FIGS. 6A and 6B show a tube array 2 including three pairs 17a, 17b, 17c of first and second tubes 18, 19.
[0101] The first tube 18 of each pair 17a, 17b, 17c includes a first end 18a and a second end 18b. Furthermore, the second tube 19 of each pair 17a, 17b, 17c includes a first end 19a and a second end 19b.
[0102] The first end 18a of the first tube 18 and the first end 19a of the second tube 19 of each pair 17a, 17b, 17c are fluidly and electrically connected. Furthermore, the second end 18b of the first tube 18 and the second end 19b of the second tube 19 of each pair 17a, 17b, 17c are fluidly and electrically connected.
[0103] To be electrically connected means that the first end 18a of the first tube 18 and the first end 19a of the second tube 19 are connected so that current can flow along the walls of the first tube 18 and the second tube 19 from the first end 18a of the first tube 18 to the first end 19a of the second tube 19.
[0104] The first ends 18a of the first tubes 18 and the first ends 19a of the second tubes 19 of each pair 17a, 17b, 17c are connected to ground. Further, the second ends 18b of the first tubes 18 and the second ends 19b of the second tubes 19 of each pair 17a, 17b, 17c are connected to ground.
[0105] The current inlet I1 is disposed in the first tube 18 of each pair 17a, 17b, 17c and is disposed at the center between the grounding of the first ends 18a, 19a and the grounding of the second ends 18b, 19b.
[0106] Furthermore, the current outlet I2 is disposed in the second tube 19 of each pair 17a, 17b, 17c at the center between the grounding of the first ends 18a, 19a and the grounding of the second ends 18b, 19b.
[0107] In the example shown in FIGS. 6A and 6B, the tube array 2 also includes a first vertical tube 20 that fluidly and electrically connects the first ends 18a, 19a of the first and second tubes 18, 19 of each pair 17a, 17b, 17c, and a second vertical tube 21 that fluidly and electrically connects the second ends 18b, 19b of the first and second tubes 18, 19 of each pair 17a, 17b, 17c.
[0108] It is advantageous to arrange the first tube 18 and the second tube 19 of each pair 17a, 17b, 17c in a U shape.
[0109] With such a configuration, a symmetrical voltage is obtained. This means that the voltage between the current inlet I1 arranged in the first tube 18 of each pair 17a, 17b, 17c and the ground of the first end portions 18a, 19a is opposite to the voltage between the current inlet I1 arranged in the first tube 18 of each pair 17a, 17b, 17c and the ground of the second end portions 18b, 19b.
[0110] The sum of the voltages applied to the points I1 and I2 corresponding to the current inlet and the current outlet respectively is equal to zero.
[0111] This eliminates the need for the electrical insulator IS18 located between the pair of the first tube 18 and the second tube 19 positioned in the middle of the set of pairs 17a, 17b, 17c and the remaining part of the tube arrangement 2. Of course, various features, modifications, and / or embodiments of the present invention can be associated with each other in various combinations as long as they are not incompatible and mutually exclusive.
[0112] The present invention also relates to a steam reforming method including the following steps. Introducing a mixture of hydrocarbon and steam into a single tube or a plurality of tubes of the aforementioned steam reforming furnace, and Heating the mixture of hydrocarbon and steam by injecting an electric current along the wall of a single tube or a plurality of tubes of the tube arrangement 2 for steam reforming of the hydrocarbon.
[0113] An electric current can be directly passed along the wall of a single tube or a plurality of tubes of the tube arrangement 2 by the conductive material of the tube.
[0114] By directly passing an electric current along the wall surface of a single tube or a plurality of tubes of the tube arrangement 2 and heating it by the Joule effect, an efficient steam reforming reaction can be caused without discharging contaminants.
[0115] In order to reduce the electric current required for heating, it is preferable to increase the electrical resistance of a single tube or a plurality of tubes of the tube arrangement 2.
[0116] For this purpose, the steam reforming method advantageously includes increasing the frequency of the current flowing through the wall of a single tube or a plurality of tubes of the tube array 2 so that the skin effect is obtained.
[0117] The skin effect refers to the tendency of an alternating current to flow near the surface or skin of a conductor, and the electrical resistance increases. In the present invention, the conductor is formed by a single tube or a plurality of tubes of the tube array 2 containing a conductive material.
[0118] It is advantageous to increase the frequency to a value in the range between 500 Hz and several kHz.
[0119] In the embodiment shown in FIG. 5, by increasing the frequency, the efficiency of the electrical insulation obtained by the electrical insulator IS2 15 is also improved.
[0120] When the frequency is increased, the efficiency of the electrical insulation obtained by the electrical insulator IS1 8 is also improved.
[0121] Therefore, by increasing the electrical resistance due to the skin effect, current can flow through the tubes of the tube array 2 and the tube connections.
[0122] To reduce the current required for heating, the steam reforming method advantageously includes increasing the frequency of the current flowing through the walls of two adjacent parallel tubes of the tube array 2 and utilizing the proximity effect.
[0123] By the synthesis of the magnetic fields of the two adjacent parallel tubes, the dissipation of power in each of the two adjacent parallel tubes increases.
[0124] The steam reforming method advantageously includes increasing the inductance of at least one electrical insulator IS1 8 disposed between a single tube or a plurality of tubes of the tube array and the remaining part 2 of the tube array to limit the flow of current from the at least one tube to the remaining part of the tube array.
[0125] In the illustrated example, the fluid heating method is a steam reforming method that includes electrically heating a mixture of hydrocarbons and gaseous steam.
[0126] In another embodiment, the fluid heating method may refer to a method other than steam reforming and may include heating a fluid other than a gas.
Claims
1. A tube array for a fluid heated furnace (1), comprising at least one tube comprising an electrically conductive material that allows an electric current to flow along the wall of the tube.
2. 2. The tube arrangement according to claim 1, wherein the at least one tube comprises a plurality of juxtaposed sections of the same tube and / or several tubes arranged in at least one bundle (9) of closely packed tube sections.
3. 3. The tube arrangement of claim 2, wherein the cross-sections of the tube portions of the bundle (9) are arranged in a circular pattern.
4. 4. The tube arrangement according to claim 1, further comprising at least one electrical insulator IS1 (8) disposed between the at least one tube and the remainder of the tube arrangement (2) and configured to limit a flow of electrical current from the at least one tube to the remainder of the tube arrangement (2).
5. 5. The tube arrangement according to claim 4, comprising at least one element (7) for positioning and holding at least one tube of the steam cracking furnace (1), said element (7) for positioning and holding comprising at least one electrical insulator IS1 (8).
6. 6. The tube arrangement of claim 4 or 5, wherein the at least one electrical insulator IS1 (8) comprises an electrically insulating material, a ferromagnetic material, a coil, a solenoid, or a combination thereof.
7. 7. The tube arrangement according to any one of claims 1 to 6, wherein the tube arrangement (2) comprises a plurality of electrical insulators IS2 (15) arranged to form a serpentine path for electricity along the tube arrangement (2).
8. The tube arrangement of claim 7, wherein the plurality of electrical insulators IS2 (15) comprises an electrically insulating material, a ferromagnetic material, a coil, a solenoid, or a combination thereof.
9. 7. The tube array of claim 1, wherein the at least one tube comprises a plurality of tubes, and the tube array (2) comprises at least one inductor (16) arranged around two adjacent parallel tubes of the plurality of tubes of the tube array (2), the at least one inductor (16) configured to cause a current to form opposing magnetic fields such that a serpentine path is formed.
10. the at least one tube includes an odd number of pairs of a first tube and a second tube, the first tube of each pair including a first end and a second end, and the second tube of each pair including a first end and a second end; a first end of the first tube and a second tube of each pair are fluidly and electrically connected, and a second end of the first tube and a second tube of the pair are fluidly and electrically connected; The first and second ends of the first and second tubes of each pair are connected to ground; Current inlet (I １ ) is disposed in the first tube of each pair at a central portion between the ground of the first end and the ground of the second end; Current output section (I ２ 7. The tube arrangement according to claim 1, wherein a ground terminal (11) is disposed in the second tube of each pair at a central portion between the ground terminals of the first end and the ground terminals of the second end.
11. A furnace for heating a fluid, comprising at least one tube array according to any one of claims 1 to 10.
12. Introducing a fluid into at least one tube of the fluid heated furnace of claim 11; and heating the fluid by injecting an electric current along a wall of said at least one tube; A method for heating a fluid, comprising:
13. The method according to claims 12 and 3, wherein the cross-sections of the tube portions of the bundle (9) are arranged in a circular pattern, preferably with the hottest tubes (10) arranged in the centre of the circular pattern and the coolest tubes (11) arranged around the periphery.
14. 14. A method according to claim 12 or 13, comprising increasing the frequency of the current through the wall of the at least one tube so as to obtain a skin effect.
15. A method according to any one of claims 12 to 14, comprising increasing the frequency of the current flowing through the walls of two adjacent parallel tubes of the tube array so as to take advantage of the proximity effect.
16. 16. The method according to any one of claims 12 to 15, comprising increasing an inductance of at least one electrical insulator IS1 arranged between the at least one tube of the tube array and the remainder of the tube array to limit the current flowing from the at least one tube to the remainder of the tube array.
17. The method according to any one of claims 12 to 16, wherein the fluid introduced into the at least one tube of the fluid heated furnace is a mixture of hydrocarbons and steam for steam cracking.