US20110155583A1

US20110155583A1 - High efficient hydrogen generation with green engergy powers

Info

Publication number: US20110155583A1
Application number: US13/044,522
Authority: US
Inventors: Haiming Li
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-03-13
Filing date: 2011-03-09
Publication date: 2011-06-30

Abstract

A novel system and method for generating hydrogen by electrolysis of water from a green power source. Electricity generated by solar panel or wind mill is measured and connected with plurality of electrolysis stacks. The number of operating electrolysis stacks are constantly controlled by a controlling mechanism that calculates an optimal operating number of electrolysis stacks using the measured electricity parameter and the operating parameter of an electrolysis unit.

Description

CROSS-REFERENCE

Priority is claimed from the U.S. Provisional Application No. 61/313,711, filed on Mar. 13, 2010, and the entirety of which is hereby incorporated by reference.

DESCRIPTION OF RELATED ART

The present application relates to a hydrogen generation system, and more particularly to a high efficient hydrogen generation system that adjusts to fluctuations and variations of the input power source, thus efficiently converting a green energy source into hydrogen fuel energy.
Note that the points discussed below may reflect the hindsight gained from the disclosed inventions, and are not necessarily admitted to be prior art.
Hydrogen has long been regarded as a clean fuel source alternative to fossil fuel energy sources. Hydrogen is non-polluting, transportable, storable, more efficient than petrol, and can be convertible directly to heat and electricity for both mobile and other applications.
Hydrogen can be generated by a number of ways, the cleanest way is through electrolysis, especially if the electricity is generated from a green energy source, such as, the solar energy or wind power. Since both water and the energy sources are renewable and inexhaustible, this is a way of high potential. However, traditionally wind and solar energies used in hydrogen electrolysis have inherent disadvantages that prevent them from being effectively and fully utilized. Because their powers are intermittent and non-dispatchable, for example, when winds are strong, the output would be higher than power demands of a traditional electrolysis system, a great portion of generated energy would be wasted. Because of this low conversion efficiency, producing hydrogen from water is of high cost, preventing hydrogen from being used as a fuel source of any significance.
Many attempts have been made in improving the efficiency and reducing cost of hydrogen production by electrolysis. For example, WO 2010/057257 A1 describes an electrolysis system that increases hydrogen production efficiency by increasing the number of electrolysis cells and electrolysis temperature using a radiation distributor. However, this design dramatically increases the complexity in safety control of the electrolysis process, and also requires additional energy in generating sufficient heat for high temperature electrolysis.
US Patent Application Publication US 2010/0259102 A1, on the other hand, describes a hydrogen generating electrolysis system that combines two different types of electrolyzer, one of a rapid dynamics electrolysis, one of a substantially slower dynamics electrolysis. The combination of different dynamic responses allows absorbing the fluctuations of the electricity generated from a green power source. Such combination, although may improve the efficiency, is limited by their inherent limitations in responding to wider range of fluctuations.
Another example, US Patent Application Publication US 2009/0178918A1, describes a hydrogen generation electrolysis system by using multiple electrolysis cells that are optimally connected with multiple solar photovoltaic cells. One or more photovoltaic cells' electric potential are measured and matched to an electrolysis cell that would optimally operate under this electric potential. The optimization process includes reducing the number of connected solar cells. By controlling the number of operating photovoltaic cells in producing electricity, this method may provide a viable solution for systems comprising many small photovoltaic cells. For large singular solar panel system, and for wind powered system, however, because of the number of choices of panels in turning on or off being limited, this method will not be applicable. On the other hand, for a system that includes hundreds or thousands of small photovoltaic cells, the controlling system will become tremendously complicated, and thus become error prone and useless.

SUMMARY

The present application discloses new approaches to make use of the non-stable stream of electricity produced from wind, solar or other renewable sources for hydrogen production. A hydrogen generating system includes plurality of electrolysis stacks and a controlling system that decides how many electrolysis stacks at each instant moment can be turned on to function in order to optimally and sufficiently make use of the current power input.
In one embodiment, an example controlling system includes a voltage or a current meter device, a programmable logic controller microchip system, a controller and plurality of switches.
In one embodiment, an example programmable logic microchip controlling system takes input of the measurement of current input electricity voltage/current in the system together with the optimal operating electricity requirement of an electrolysis cell or stack, determines the optimal number of operating electrolysis cells and sends signals to the controller which then turns on or off some of the electrolysis cells accordingly.
In one embodiment, the microchip controlling system takes input parameters from an input interface which presets the maximum range of system working voltages/currents and the maximum number of electrolysis stacks/cells, to prevent the system from being over charged.
In one embodiment, the total number of stacks or cells of electrolysis units in the system may be added or reduced, individual electrolysis unit is removably connected and mounted with the system. Produced hydrogen is collected through the same filter unit and stored together.
In one embodiment, a water circulating system is included to keep the electrolysis units at a constant operating temperature.
In one aspect of an embodiment, plurality of electrolysis stacks or cells are connected in series with a power source, and each electrolysis stack or cell is connected with an electronic relay switch that is independently connected with the controller.
In another aspect of an embodiment plurality of electrolysis stacks or cells are connected in parallel to a power source, and each electrolysis stack or cell is connected with an electronic switch that is independently connected with the controller.
The disclosed innovation, in various embodiments, provides one or more of at least the following advantages. However, not all of these advantages result from every one of the innovations disclosed, and this list of advantages does not limit the various claimed inventions. This system and method provide great flexibility and capability in adding and reducing the number of electrolysis units, allowing this hydrogen generation system be operated in high efficiency with variety of green energy power sources that produce a non-stable and intermittent electricity in wide amplitude of fluctuations. The combination of high flexibility and high efficiency will greatly reduce the cost of hydrogen and improve the popularity of hydrogen in replacing fossil fuels as a fuel energy source.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed invention will be described with reference to the accompanying drawings, which show important sample embodiments of the invention and which are incorporated in the specification hereof by reference, wherein:

FIG. 1 schematically shows an example adaptive hydrogen generation system in accordance with this application.

FIG. 2 schematically shows another example adaptive hydrogen generation system in accordance with this application.

FIG. 3 schematically shows an example structure of an electrolysis stack having multiple electrolysis cells or slots in accordance with this application.

FIG. 4 schematically shows an example adaptive controlling mechanism for a hydrogen generation system in accordance with this application.

FIG. 5 schematically shows another example adaptive controlling mechanism for a hydrogen generation system in accordance with this application.

FIG. 6 schematically shows an example electronic structure of a hydrogen generation system in accordance with this application.

FIG. 7 schematically shows a flow chart of command chains in an example hydrogen generation system in accordance with this application.

DETAILED DESCRIPTION OF SAMPLE EMBODIMENTS

The numerous innovative teachings of the present application will be described with particular reference to presently preferred embodiments (by way of example, and not of limitation). The present application describes several embodiments, and none of the statements below should be taken as limiting the claims generally.
For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and description and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the invention. Additionally, elements in the drawing figures are not necessarily drawn to scale, some areas or elements may be expanded to help improve understanding of embodiments of the invention.
The terms “first,” “second,” “third,” “fourth,” and the like in the description and the claims, if any, may be used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable. Furthermore, the terms “comprise,” “include,” “have,” and any variations thereof, are intended to cover non-exclusive inclusions, such that a process, method, article, apparatus, or composition that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, article, apparatus, or composition.
It is contemplated and intended that the design apply to any suitable power sources; for clarity reason, the examples are given based on either solar power or wind generated power. Also for hydrogen generation through water electrolysis, currently there are Proton Exchange Membrane technology and alkaline technology. It is contemplated and intended that the described innovation may be used in combination of any type of electrolysis technologies, and an ordinary person in the art will know the necessary modifications and changes to be made.
In reference to FIG. 1, an adaptive hydrogen generation system using electrolysis technology is described.
The hydrogen generating system 101 includes a controlling system 2, a water cooling system 3, electrolysis stacks 4, 5, 6, an O₂filter 9, an H₂filter 10, a water refill 11, and a pressure self-regulating valve 12. The system is connected to power source 1. Electrolysis stacks 4, 5, 6 or more are connected in series in this example. In operation, each of electrolysis stacks 4, 5, and 6 produces oxygen 7 and hydrogen 8 which is filtered through 9 and 10 respectively and is collected into their storage container 13 and 14 respectively. More electrolysis stacks may be further installed and connected to the system if the capacity of the power source changes.
Power source 1 may include wind turbines, solar panels or any other intermittent power sources. In operation, controlling system 2 constantly measures the electricity from Power Source 1, which could have a wide arrange of voltages and currents, and decides the corresponding number of electrolysis stacks needed to be connected to the power source 1 in order to maximally utilize the electricity.
If controlling system 2 determines that the electricity from power source 1 is just sufficient to run electrolysis stacks 4 and 5, only electrolysis stacks 4 and 5 will be turned on with power source 1, and electrolysis 6 will remain operationally turned off. The produced O ₂ 7 and H ₂ 8 will be conducted to Filter 9 and Filter 10 to be cleaned. Through Pressure Self-regulating Valve 12, filtered O₂ 13 and H ₂ 14 will be directed into their separate storage devices. The water cooling system 3 constantly circulates water to keep the hydrogen generating system 101 at a stable operating temperature.
The electrolysis stacks may be connected in any suitable ways. In reference to FIG. 2, an example of embodiment wherein electrolysis stacks are connected in parallel is shown. Power Source 21 includes wind, solar, and any other intermittent power sources. Connected to Power Source 21 are Monitor and Controller 20, and connected in parallel, plurality of controlling components 30, and their respectively controlled electrolysis stacks/ units 40, 50, 60. Each of the controlling components 30 controls the functional on and off status of the respective electrolysis stack or unit.
The number of electrolysis stacks and controlling components may be expanded to as many as needed, depending on the system needs and the power source used. Oxygen gas separator 80, Oxygen Gas washer 90, Oxygen Pressure controller 100, Hydrogen gas separator 110, Hydrogen gas washer 120, Hydrogen Pressure controller 130, Water Tank and Balancer 140, Flame arrester 150 may further be included in the hydrogen generation system for hydrogen and oxygen collections.
Water Tank and Balancer 140 stores and refills water for electrolysis stacks to keep sufficient water level in each operating electrolysis stack or unit. Oxygen gas separator, Oxygen Gas washer, Oxygen Pressure controller, Hydrogen gas separator, Hydrogen Gas washer, and Hydrogen Pressure controller are also connected to water tank 140 to maintain their proper water levels.
In a preferred embodiment, the produced hydrogen gas is conducted into hydrogen gas separator 110 to be separated from water vapor, then into Hydrogen Gas washer 120 to be cleaned, and then goes through a Flame Arrester 150-2 into a Hydrogen Pressure controller 130 to be cooled and properly pressure adjusted. Hydrogen gas may be further conducted through Water Tank and Balancer 140 for further cooling down and finally be conducted to storage via Flame Arrester 150.
Similarly, the generated oxygen gas first flow into oxygen gas separator 80 to be rid of water vapor, then into Oxygen Gas washer 90 to be cleaned, then goes through a Flame Arrester 150-1 into Oxygen Pressure controller 100 to be cooled and properly pressure adjusted and finally stored.
In reference to FIG. 3, each electrolysis stack of FIG. 2 may further include plurality of electrolysis slots connected in series or in parallel. For example, as shown in FIG. 3, electrolysis stack 160 may contain M electrolysis slots, connected in series. Each electrolysis slot may operate under about 2 Volt DC electricity, and electrolysis stack 160 would operate preferably under about M*2 Voltage DC electricity.
The controlling system may be slightly different for in series and for in parallel electrolysis stack systems. In reference to FIGS. 4 and 5, where FIG. 4 shows an example of electrolysis stacks connected in series and FIG. 5 shows an example of electrolysis stacks connected in parallel, the controlling system 2 includes a voltage/ current meter 416 or 518, a rectifier 417 or 519, a programmable logic controller (PLC) circuit chip 418 or 520, a controller 419 or 521, relays 420 or controlling components or switches 522. In FIG. 4 plurality of electrolysis stacks 421 are connected in series and their respective controlling relays 20 are connected in parallel loops to the controller 419 which is connected with the rectifier and the PLC. In FIG. 5, plurality of electrolysis stacks 523 are connected in parallel loops and inside each of their loops connected their respective controlling switch 522 which is also electrically connected to the controller 521. The controlling system is connected with power source 415 in FIG. 4 and power source 517 in FIG. 5.
In operation, the electricity from the power source is measured by a voltage/ current meter 416 or 518. The measured electricity information is then sent to PLC chip 418 or 520. Based on the electricity information and the operating parameters of an electrolysis stack, the PLC calculates how many electrolysis stacks can operate optimally and can maximally consume all the electricity power. The calculation is then sent to controller unit 419 or 521. Upon receiving the calculation results from a PLC chip 418 or 520, controller unit 419 or 521 then sends different electrical signals to each of the relays 420 or controlling components 522, commanding them either to turn on or to turn off from the power connection for their respective electrolysis stacks in accordance with the calculation.
For instance, in FIG. 4, if the DC electricity power source 415 can produce electricity of a Voltage ranging 0-600 V, we will customize the system into 30 electrolysis stacks 421-1, 421-2 . . . 421-30. Each of electrolysis stacks 421 contains 10 electrolysis slots, so each electrolysis stack can work with 10*2 voltage DC electricity, just like electrolysis stack 160 in FIG. 3. When the electric voltage is between 29*20 V˜30*20 V, relay 420-1 is commanded to turn on while other relays 420-2 to 420-30 are disconnected, allowing all thirty electrolysis stacks 421-1 to 421-30 to turn on and function. When the electric voltage is between 560˜580 V, relay 420-2 is connected and all other relays 420-1, 420-3, 420-4, . . . , 420-30 are disconnected, allowing twenty nine electrolysis stacks 421-2, 421-3, . . . , 421-30 operating, while 421-1 remains non-functional similarly, when the electric voltage goes below 20 V, relay 420-30 is connected and all other relays 420-1, 420-2, . . . , 420-29 are disconnected, therefore only one electrolysis stack 421-30 remains operating.
Similarly, for parallel connections in FIG. 5, for example, assuming each electrolysis stack can work with X Amp DC electricity, when the electric current is (N−1)*X Amp˜N*X Amp, all controlling components 522-1 to 522-N are turned on, allowing all electrolysis stacks 523-1 to 523-N switch on and operate; when the electric voltage is below M*X Amp, only controlling component 522-N is connected and all other controlling components 522-1 to 522-N-1 are disconnected, therefore only one electrolysis stack 523-N remains functioning.
The controlling relays or switches may either be external to an electrolysis stack or unit, or be a built-in part of an electrolysis stack or unit.
FIG. 6 demonstrates an example embodiment of a controlling system 2. It includes an input interface 622, a CPU 623, a storage device 624, an output interface 625, a transistor 626, a relay 627. The controlling system interacts and controls electrolysis stack 628.
In operation, input interface 622 receives an electronic signal from an external source, such as voltage information from a voltage meter, and transfers the signal to CPU 623. CPU 623 then processes the signal and performs a calculation based on programs stored in storage device 624, and determines whether or not the electrolysis stack 628 should be functioning under this voltage information. Then a command is generated and sent to output interface 625 which in turn controls the voltage of transistor 626. If CPU 623 decides to turn on the electrolysis stack 628, the signal from output interface 625 will keep the base of transistor 626 at Vih, therefore transistor 626 will be connected, and relay 627 is turned on, electrolysis stack 628 will be connected to the power source and functioning. If CPU 623 decides the current electricity is not sufficient for electrolysis stack 628 to function, the signal from output interface 625 will keep the base of transistor 626 at Vil, causing transistor 626 to open, and relay 627 be turned off, and the electrolysis stack 628 will not be working.
Input interface 622 may also receive settings about the system, for example, the maximum voltage or currents for the system, the maximum number of electrolysis stacks, and the optimum operating parameter for each or certain electrolysis stacks, the sequential order of turning on or off the electrolysis stacks, etc.
FIG. 7 shows an example command chain of the system. At steps 701 and 703, power is connected and measured, the measured result is sent to CPU of a control center. At step 704, the CPU takes the parameter of the current electricity and the parameters of an electrolysis stack, calculates the optimal operating combinations of the electrolysis stacks according to either the pre-settings or instant measurement, and sends the turning on and off signal to a controller at step 705. Electrolysis stacks are then turned on or off at step 707, and the generated hydrogen and oxygen gas are collected at step 709.
The electricity power source may not be limited to one, the system may be connected to plurality of power sources concurrently and the system parameters are constantly measured with voltage and/or current meter(s).
As will be recognized by those skilled in the art, the innovative concepts described in the present application can be modified and varied over a tremendous range of applications, and accordingly the scope of patented subject matter is not limited by any of the specific exemplary teachings given. It is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.
Additional general background, which helps to show variations and implementations, may be found in the following publications, all of which are hereby incorporated by reference herein for all purposes: WO 2010/057257 A1, US 2010/0259102 A1, and US 2009/0178918 A1.
None of the description in the present application should be read as implying that any particular element, step, or function is an essential element which must be included in the claim scope: THE SCOPE OF PATENTED SUBJECT MATTER IS DEFINED ONLY BY THE ALLOWED CLAIMS. Moreover, none of these claims are intended to invoke paragraph six of 35 USC section 112 unless the exact words “means for” are followed by a participle.
The claims as filed are intended to be as comprehensive as possible, and NO subject matter is intentionally relinquished, dedicated, or abandoned.

Claims

1. A hydrogen generation device system from an electricity source, comprising:

a controlling device module electronically connected with said electricity source;

at least one electrolysis unit, electronically connected with said controlling device module, which in operation generates hydrogen by electrolyzing water using said electricity source; and

a hydrogen collection device module collecting said hydrogen into storage,

wherein said controlling device module measures a parameter of said electricity and directs said electrolysis unit's operation in accordance to said parameter of said electricity.

2. The hydrogen generation device system of claim 1, wherein said electrolysis unit is connected to said controlling device module in parallel.

3. The hydrogen generation device system of claim 1, wherein said electrolysis unit is connected to said controlling device module in series.

4. The hydrogen generation device system of claim 1, wherein said electrolysis unit is removably connected to said hydrogen generation device system, and is expandable or reducable in number.

5. The hydrogen generation device system of claim 1, wherein said electrolysis unit comprises a plurality of sub-electrolysis cells.

6. The hydrogen generation device system of claim 1, wherein said controlling device module receives a pre-setting parameter about said electrolysis unit and about said electricity power source.

7. A controlling device module for a hydrogen generation system by electrolysis, comprising:

an electricity measuring device for measuring an input electricity parameter;

an input device module for storing at least one system operating parameter;

a controlling CPU, electronically connected with said electricity measuring device and said input device module, generating a controlling signal by calculating a maximum operating number of electrolysis units based on said electricity parameter received and said system operating parameter; and

a controller for receiving said controlling signal and for turning on and off an electrolysis unit in accordance to said signal.

8. The controlling device module of claim 7 is connected electronically with plurality of electrolysis units that produce hydrogen from electrolysis of water using said input electricity.

9. The controlling device module of claim 8, wherein said plurality of electrolysis units are connected in parallel.

10. The controlling device module of claim 8, wherein said plurality of electrolysis units are connected in series.

11. The controlling device module of claim 8, wherein each of said electrolysis units is controlled by an independent electronic switch.

12. The controlling device module of claim 8, wherein said electrolysis units are installed removably, and are expandable in number.

13. The controlling device module of claim 8, wherein said input device module receives a pre-set parameter from a manual input.

14. A method for generating hydrogen from a green power source, comprising the actions of:

measuring an electricity parameter from said green power source;

calculating an optimal number of operating electrolysis units based on the electricity parameter; and

turning on the optimal number of electrolysis units to generate hydrogen by electrolysis using the electricity from said green power source.

15. The method of claim 14, wherein said electrolysis units are connected in parallel.

16. The method of claim 14, wherein said electrolysis units are connected in series.

17. The method of claim 14, wherein each of said electrolysis units is controlled by a built-in electronic switch which receives a command from a controller.

18. The method of claim 14 further comprising the action of filtering said hydrogen automatically.

19. The method of claim 14 further comprising the action of manually inputting a system operating parameter.

20. The method of claim 14, further comprising measuring an operating parameter of an electrolysis unit.