Electrolysis arrangement

Abstract

Provided is an electrolysis arrangement including a plurality of electrolytic units, wherein each electrolytic unit includes an electrolytic cell and an AC-DC power converter configured to provide DC power for that electrolytic cell; a plurality of electrolytic assemblies, wherein each electrolytic assembly includes a number of electrolytic units; at least one wind turbine including an electrical generator with a number of armature windings, wherein each armature winding provides AC power to one electrolytic assembly; and a converter unit controller configured to regulate the AC-DC power converters of the electrolytic units on the basis of the power output of an electrical generator. A method of operating such an electrolysis arrangement is also provided.

Claims

1. An electrolysis arrangement comprising: a plurality of electrolytic units, wherein each electrolytic unit comprises an electrolytic cell and an AC-DC power converter configured to provide DC power for that electrolytic cell; a plurality of electrolytic assemblies, wherein each electrolytic assembly comprises a number of electrolytic units of the plurality of electrolytic units; at least one wind turbine comprising an electrical generator with a number of armature windings, wherein each armature winding provides AC power to one electrolytic assembly of the plurality of electrolytic assemblies; and a converter unit controller configured to control the AC-DC power converters of respective electrolytic units of the plurality of electrolytic units on the basis of the power output of the electrical generator.

2. The electrolysis arrangement according to claim 1, wherein each AC-DC power converter is configured to provide a percentage of rated DC power of the corresponding electrolytic cell.

3. The electrolysis arrangement according to claim 1, wherein the converter unit controller is configured to regulate the respective AC-DC power converters of the respective electrolytic units to distribute available power over an optimum number of electrolytic units of the plurality of electrolytic units.

4. The electrolysis arrangement according to claim 1, wherein the respective AC-DC power converters of the respective electrolytic units are respective DC current controllers configured to control the current density of the respective electrolytic units.

5. The electrolysis arrangement according to claim 1, comprising a switch between each armature winding and the one electrolytic assembly provided with AC power by the respective armature winding, and a switch controller configured to actuate the switch.

6. The electrolysis arrangement according to claim 1, wherein each electrolytic assembly comprises at least two electrolytic units of the plurality of electrolytic units.

7. The electrolysis arrangement according to claim 1, wherein the electrolytic cell of at least one electrolytic unit of the plurality of electrolytic units is constructed to perform electrocatalytic conversion of water into hydrogen and oxygen.

8. The electrolysis arrangement according to claim 1, comprising a desalination module configured to desalinate seawater to obtain water for the electrolytic cell of at least one electrolytic unit of the plurality of electrolytic units.

9. The electrolysis arrangement according to claim 1, wherein the electrolytic cell of at least one electrolytic unit of the plurality of electrolytic units is constructed to perform electrocatalytic conversion of carbon dioxide into a further gas.

10. The electrolysis arrangement according to claim 1, wherein the number of armature windings comprises at least two armature windings.

11. The electrolysis arrangement according to claim 1, wherein the electrical generator is further configured to provide power to a further component of the electrolysis arrangement.

12. The electrolysis arrangement according to claim 1, wherein the at least one wind turbine comprises a plurality of wind turbines.

13. A method of operating the electrolysis arrangement according to claim 1 comprising the steps of: operating the electrical generator of the at least one wind turbine to generate AC power in one or more of the at least one armature windings and, on the basis of the generated AC power, regulating the respective AC-DC power converters of the respective electrolytic units of the respective electrolytic assemblies connected to the one or more of the at least one armature windings.

14. The method according to claim 13, further comprising determining the power output of the electrical generator of the at least one wind turbine; selecting a subset of the plurality of electrolytic units to be driven; and regulating the respective AC-DC power converters of the selected subset of the plurality of electrolytic units.

15. The method according to claim 13, further comprising opening a switch between the one or more of the at least one armature windings and the respective electrolytic assembly connected to the one or more of the at least one armature windings to isolate a faulty component.

16. An electrolysis arrangement comprising: a first electrolytic assembly including a first electrolytic unit, wherein the first electrolytic unit comprises a first electrolytic cell and a first AC-DC power converter configured to provide DC power for the first electrolytic cell; a second electrolytic assembly including a second electrolytic unit, wherein the second electrolytic unit comprises a second electrolytic cell and a second AC-DC power converter configured to provide DC power for the second electrolytic cell; at least one wind turbine comprising an electrical generator with a first armature winding and a second armature winding, wherein the first armature winding provides AC power to the first electrolytic assembly and the second armature winding provides AC power to the second electrolytic assembly; and a converter unit controller configured to control the first AC-DC power converter and the second AC-DC power converter on the basis of a power output of the electrical generator.

17. The electrolysis arrangement of claim 16, wherein the first electrolytic assembly includes a third electrolytic unit, wherein the third electrolytic unit comprises a third electrolytic cell and a third AC-DC power converter configured to provide DC power for the third electrolytic cell.

18. The electrolysis arrangement of claim 17, wherein the second electrolytic assembly includes a fourth electrolytic unit, wherein the fourth electrolytic unit comprises a fourth electrolytic cell and a fourth AC-DC power converter configured to provide DC power for the fourth electrolytic cell.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

(2) FIG. 1 shows embodiments of the inventive electrolysis arrangement;

(3) FIG. 2 shows a simplified embodiment with a generator which drives an electrolytic assembly; and

(4) FIG. 3 shows the electrolysis arrangement can comprise several offshore wind turbines.

DETAILED DESCRIPTION

(5) FIGS. 1-3 show simplified block diagrams to illustrate the inventive electrolysis arrangement 1. As shown in FIG. 3, the electrolysis arrangement 1 can comprise several offshore wind turbines 10. FIG. 1 shows the generator 10G of one such wind turbine, for example, a 8 MW generator 10G that has two windings 10W. Each winding 10W can therefore produce up to 4 MW of AC power when the wind turbine is running at its rated output.

(6) Each winding 10W is connected—by means of a switch S—to an electrolytic assembly 11A. The switches are controlled by a switch controller SC.

(7) The components that together comprise an electrolytic assembly 11A are collectively indicated by a bounding rectangle drawn with a broken line. Each electrolytic assembly 11A comprises a number of electrolytic units 11U, each with an AC-DC power converter 110 and an electrolysis cell 11 or stack 11. The components that together comprise an electrolytic unit 11U are collectively indicated by the bounding rectangle at the lower part of the diagram (drawn with a dotted line).

(8) A converter unit controller 11C issues control signals 110C for each AC-DC power converter 110. A control signal 110C for a power converter 110 specifies the fraction of rated power that is to be provided to the corresponding cell 11. The converter unit controller 11C may receive data D from a wind turbine controller or similar (for example the quantity of rated power that is being generated) in order to determine the available power that can be distributed between the electrolytic assemblies 11A. Each AC-DC power converter 110 converts an AC input to a DC voltage UDC and a DC current IDC at levels determined by the control signal 110C it received from the converter unit controller 11C.

(9) An electrolysis stack 11 is fed with an input material 11_in, and its output 11_out can be one or more products. For example, water electrolysis can be done on purified water 11_in with the addition of a suitable electrolyte, and the output 11_out in this case is hydrogen H.sub.2 and/or oxygen O.sub.2.

(10) The number of electrolysis stacks 11 that can be operational at any one time will depend on the available power, which in turn depends on the wind speed. FIG. 2 shows a simplified embodiment with a generator 10G that has two windings 10W, each of which drives an electrolytic assembly 11A, and each electrolytic assembly 11A comprises two electrolytic units 11U. The two electrolytic assemblies are labelled 11A:1 and 11A:2; the two electrolytic units of the first electrolytic assembly 11A:1 are labelled 11U:1a and 11U:1b; and the two electrolytic units of the second electrolytic assembly 11A:2 are labelled 11U:2a and 11U:2b. The available power may be distributed among the electrolytic units so that an optimum utilization is achieved. The following table illustrates an exemplary distribution:

(11) TABLE-US-00001 Power 11A:1 11U:1a 11U:1b 11A:2 11U:2a 11U:2b 100% 50 25 25 50 25 25  60% 36 20 16 24 12 12  40% 40 20 20 0 0 0  20% 20 20 0 0 0 0

(12) At 100% capacity, the power output of the generator is evenly distributed over both electrolytic assemblies. At full generator power, each electrolytic unit 11U is driven by 25% of the available power.

(13) The second row illustrates a situation in which the wind speed drops so that the power output of the generator reduces to 60%. Here, the available power is distributed so that the first electrolytic assembly 11A:1 is driven by 36% of full power, while the second electrolytic assembly 11A:2 is driven by 24% of full power. The electrolytic units 11U:1a and 11U:1b of the first electrolytic assembly 11A:1 are driven at 20% and 16% of full power respectively, while the electrolytic units 11U:2a and 11U:2b of the second electrolytic assembly 11A:2 are each driven at 12% of full power.

(14) The third row illustrates a situation in which the wind speed drops even further, so that the power output of the generator reduces to 40%. This power is generated in a single winding. Here, the second electrolytic assembly 11A:2 is “removed”, e.g., by opening the corresponding switch or by issuing appropriate control signals to the converter unit controller. The available power is dedicated to the first electrolytic assembly 11A:1, and its electrolytic units 11U:1a and 11U:1b are driven at 20% and 20% of full power respectively.

(15) The fourth row of the table illustrates a situation in which the wind speed drops even further, so that the power output of the generator reduces to 20%. Again, this power is generated in a single winding, and the second electrolytic assembly 11A:2 remains disconnected. The available power is dedicated to the first electrolytic assembly 11A:1 but is only enough to efficiently drive a single electrolytic units 11U:1a. The other electrolytic unit 11U:1b is not driven.

(16) FIG. 3 shows a further embodiment of the inventive electrolysis arrangement 1. Here, the diagram indicates several wind turbines 10, for example in a wind park configuration. The collective outputs 11_out of the electrolysis assemblies 11A feed into a pipeline 15, for example a pressurized hydrogen pipeline for transporting hydrogen to an onshore facility.

(17) Although the present invention has been disclosed in the form of embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention. For example, a wind turbine generator may have a single winding that provides power to a single electrolytic assembly. In such a realisation, electrolysis can be performed when there is sufficient wind energy to drive the complete electrolytic assembly.

(18) For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements. The mention of a “unit” or a “module” does not preclude the use of more than one unit or module.