Device and method for heating a fluid in a pipeline using three-phase current

Patent metadata

Field	Value
Publication number	US-10774969-B2
Application number	US-201515318680-A
Country	US
Kind code	B2
Filing date	Jun 18, 2015
Priority date	Jun 26, 2014
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

A device for heating a fluid, including at least one electrically conductive pipeline for accommodating the fluid, and at least one voltage source connected to a respective pipeline. The voltage source is designed to generate an electric current in the connected pipeline which heats the pipeline in order to heat the fluid. Each voltage source has M outer conductors, where M is a natural number greater than or equal to two. Each voltage source is designed to provide an AC voltage at the outer conductors, wherein those AC voltages are phase-shifted through 2π/M with respect to one another, and wherein the outer conductors are electrically conductively connected to the pipeline such that a star circuit is formed.

First claim

The invention claimed is:

1. A method for heating a fluid, the method comprising:
providing a device including
at least one electrically conductive pipeline for accommodating the fluid,
at least one voltage source having at least M outer conductors, where M is a natural number of greater than or equal to two, and

conductive connections between the outer conductors of the at least one voltage source and the at least one pipeline forming a star circuit, in which each outer conductor is electrically conductively connected to a neutral point of the star circuit over at least part of the at least one pipeline,
providing an alternating current (AC) voltage at each of the outer conductors of the voltage source such that the AC voltages are phase-shifted with respect to one another through 2π/M,
generating an electric current in the at least one pipeline using the at least one voltage source and thereby heating the at least one pipeline,
passing the fluid through the at least one pipeline and heating said fluid in said at least one pipeline by virtue of said at least one pipeline being heated by the electric current generated using the at least one voltage source, and
providing said fluid as a mixture of hydrocarbons and steam, preheating said fluid before passing said fluid through the at least one pipeline of the device, and thermally cracking the hydrocarbons, or
providing the at least one pipeline in the form of at least one catalyst-filled reaction tube of a reformer.

2. The method according to claim 1 , wherein each of the at least one voltage source has a neutral conductor,
the method further comprising electrically conductively connecting the neutral conductor to the neutral point of the star circuit.

3. The method according to claim 1 , wherein M is equal to three.

4. The method according to claim 1 , wherein said at least one pipeline has a plurality of limbs, wherein each limb has a first and a second end section and a central section,
the method further comprising fluidically and electrically conductively connecting the two end sections to one another.

5. The method according to claim 4 , further comprising electrically conductively connecting the two end sections of each limb to the neutral point.

6. The method according to claim 4 , further comprising electrically conductively connecting the central connections of each limb to the outer conductor of the at least one voltage source connected to the at least one pipeline.

7. The method according to claim 4 , further comprising fluidically and electrically conductively connecting the second end section of a first limb to the first end section of a second limb or integrally forming the second end section of the first limb on said first end section of the second limb, and
fluidically and electrically conductively connecting the second end section of the second limb to the first end section of a third limb or integrally forming the second end section of the second limb on said first end section of the third limb, wherein the first end section of the first limb forms an inlet for feeding the fluid into the at least one pipeline, and wherein the second end section of the third limb forms an outlet for allowing the fluid to pass out of the at least one pipeline.

8. The method according to claim 1 , wherein said at least one pipeline has a plurality of limbs, wherein each limb has a first and a second end section and a central section,
wherein the limbs are not fluidically connected to one another,
the method further comprising conducting a fluid within each limb to be heated separately from one another.

9. The method according to claim 4 , wherein each of the limbs form a loop, wherein a central section of the limb forms an end of the loop, wherein in the region of the end, the respectively assigned outer conductor is electrically conductively connected to the limb.

10. The method according to claim 4 , wherein the limbs each extend along a longitudinal axis, wherein each of the limbs have the same length along the longitudinal axis.

11. The method according to claim 4 , wherein the end sections of the limbs of the at least one pipeline are arranged in a central region, from which the limbs extend outwards along a radial direction.

12. The method according to claim 10 , wherein the longitudinal axes of each two adjacent limbs enclose an angle of 120°.

13. The method according to claim 1 , further comprising fluidically connecting a plurality of the least one pipeline in series with one another, such that the fluid can flow through said plurality of the least one pipeline successively.

14. The method according to claim 1 , wherein a plurality of the least one pipeline is configured to be parallel, such that the fluid can be divided among the parallel pipelines.

15. The method according to claim 1 , further comprising:
generating the polyphase alternating current in the least one pipeline using the at least one voltage source connected to the at least one pipeline, wherein an AC voltage is provided at the outer conductors of the at least one voltage source.

16. The method according to claim 15 , wherein the fluid that is heated is a hydrocarbon to be cracked thermally or a mixture of hydrocarbons.

17. The method according to claim 15 , wherein the fluid that is heated is water or steam, wherein the water or steam is heated to a reactor inlet temperature of 550° C. to 700° C. to form heated steam, and further comprising adding the resultant heated steam to a hydrocarbon to be cracked.

18. The method according to claim 15 , wherein the fluid that is heated is combustion air from a reformer furnace, and said combustion air is heated to a temperature of 200° C. to 800° C.

19. The method according to claim 18 , wherein said combustion air is heated to a temperature of 400° C. to 700° C.

20. A thermal cracking or reformer furnace for heating a fluid, comprising
at least one electrically conductive pipeline for accommodating the fluid, and
at least one voltage source, wherein each voltage source is assigned to and connected to one of the at least one pipeline, wherein each voltage source is designed to generate an electric current in the pipeline to which it is connected to thereby heat the pipeline in order to heat the fluid accommodated in the pipeline,
wherein each voltage source has at least M outer conductors, where M is a natural number of greater than or equal to two, and wherein each voltage source is designed to provide an AC voltage at its outer conductors, wherein each of the AC voltages is phase-shifted with respect to one another through 2π/M, and wherein the outer conductors of the each voltage source are electrically conductively connected to the respective pipeline in such a way that a star circuit is formed, in which each outer conductor is electrically conductively connected to a neutral point of the star circuit over at least part of the respective pipeline.

21. The thermal cracking or reformer furnace according to claim 20 , wherein each voltage source of the at least one voltage source has a neutral conductor such that the neutral conductor of each voltage source is electrically conductively connected to the neutral point.

22. The device according to claim 20 , wherein each pipeline of the at least one pipeline includes a plurality of limbs, such that each limb has a first and a second end section and a central section, which fluidically and electrically conductively connects the two end sections to o

Assignees

• Linde Ag

Inventors

• Eder Kurt

Classifications

• H05B2203/022

  Heaters specially adapted for heating gaseous material · CPC title

• H05B2203/021

  Heaters specially adapted for heating liquids · CPC title

• H05B3/0004 Primary

  Devices wherein the heating current flows through the material to be heated (Circuit arrangements for heating by passing the current directly across the material to be heated H05B3/0023; granular, powdered or fluid material H05B3/60) · CPC title

• F24H1/105

  formed by the tube through which the fluid flows · CPC title

• H05B3/40 Primary

  Heating elements having the shape of rods or tubes (H05B3/62, H05B3/68, H05B3/78 take precedence) · CPC title