DE102007001976A1 - Energy conversion, storage and delivery device for use in e.g. vehicle, has photovoltaic unit attached to fuel cells so that part of flow water flowing on anode and cathode sides is converted into hydrogen and oxygen by hydrolysis on sides - Google Patents

Abstract

The invention relates to a device for converting, storing and emitting energy, comprising a photovoltaic device (2) with a solar cell (6) for converting electromagnetic solar radiation (7) into electricity, a fuel cell device (3) with a fuel cell (9) Generation of electric current from hydrogen and oxygen, comprising an electrolyte (10) separating an anode side (11) with an anode (13) from a cathode side (12) with a cathode (14), communicating with the anode side (11) Hydrogen storage (4) and one communicating with the cathode side (12) communicating oxygen storage (5). According to the invention, in an energy storage operation, the photovoltaic device (2) is electrically connected to the anode (13) and to the cathode (14) of the fuel cell (9), such that with the electric current generated by the photovoltaic device water, which is on the anode side ( 11) and on the cathode side (12) of the fuel cell (9) is converted by electrolysis into hydrogen and oxygen.

Description

The The present invention relates to a device for conversion, Storage and release of energy.

in the With regard to the pollution of the environment, to an increasing Energy demand, rising energy costs and falling oil, natural gas and uranium increases the need for devices for the use of regenerative Powers whose operation as well low in pollutant emissions.

Known are photovoltaic devices that at least one solar cell for Conversion of electromagnetic solar radiation into electrical Have current. With photovoltaic devices can out of solar radiation Electricity can be generated directly without pollutants arise; At the same time, solar radiation is virtually unlimited to disposal.

Basically Also known fuel cell devices, the at least one fuel cell to generate electricity from hydrogen and oxygen exhibit. In each fuel cell is an electrolyte comprising an anode side having an anode from a cathode side with a cathode separates. Those in hydrogen and in oxygen chemically stored energy can be converted into electricity with the help of the electrolyte Power can be converted, which can be tapped off at the electrodes. The reaction product is water.

The present invention employs dealing with the problem, for the provision of electric power is an advantageous option show, in particular, by their regenerability and by their low pollutant emissions as well as by a high Availability distinguished.

This Problem is inventively things the independent one claims solved. Advantageous embodiments are the subject of the dependent Claims.

The This invention is based on the general idea of a fuel cell assembly the respective fuel cell to carry out an electrolysis operate to generate hydrogen and oxygen from water, where required for this Electric power in particular from a photovoltaic device is provided for this purpose in a corresponding manner is connected to the electrodes of the respective fuel cell. By the proposal according to the invention can the fuel cell device be used to electrical To transform energy by electrolysis into chemical energy, which can be stored in the form of hydrogen and oxygen. To a later one The chemically bound energy can be recovered with the help of the Fuel cell device are converted into electrical energy, for example, to an electrical consumer with electrical Supply electricity. Suggests this In particular, the invention provides a device comprising a photovoltaic device and a fuel cell device comprises, in addition to equip a hydrogen storage and an oxygen storage, around during the an energy storage operation produced electrolysis products separately to save. Furthermore, an appropriate water supply can optionally be provided be that for the energy storage operation, the electrodes of the respective fuel cell supplied with water. Within this device, the fuel cell device operates with the mentioned storage as a kind of rechargeable battery or accumulator.

Essential is in the invention that the fuel cell device configured is that it can also be used for the electrolysis of water by their electrodes supplied in a corresponding manner with electric current while in contact with water. The one used for electrolysis Electric power may preferably be from a photovoltaic device come. It is the same in principle possible, this electric current through a wind turbine or by a Hydroelectric power plant or with the help of a Brennkrafteinrichtung provide.

Further important features and advantages of the invention will become apparent from the Dependent claims, from the drawings and from the associated description of the figures the drawings.

It it is understood that the above and the following yet to be explained features not only in the specified combination, but also in other combinations or alone, without to leave the scope of the present invention.

preferred embodiments The invention are illustrated in the drawings and in the following description explains where like reference numerals refer to the same or similar or functionally identical components relate.

It show, in each case schematically,

1 a highly simplified schematic diagram of a device for the conversion, storage and release of energy,

2 a perspective view of a fuel cell,

3 a view like in 2 but in a different perspective,

4 an exploded view of the fuel cell,

5 a view like in 4 but in another embodiment.

Corresponding 1 includes a device 1 used for the conversion, storage and distribution of energy, a photovoltaic device 2 , a fuel cell device 3 , a hydrogen storage 4 and an oxygen storage 5 , The photovoltaic device 2 has at least one solar cell 6 on. In the example are four solar cells 6 shown; Likewise, more or fewer solar cells 6 possible. The respective solar cell 6 is conventionally designed to undergo conversion of electromagnetic solar radiation 7 , which is indicated here by arrows, allows in electrical current. The electrical current can be via appropriate power lines 8th at the photovoltaic device 2 or at the respective solar cell 6 be tapped.

The fuel cell device 3 includes at least one fuel cell 9 , In the example is only a single fuel cell 9 reproduced; likewise, the fuel cell device 3 several fuel cells 9 have, in particular a stack of fuel cells 9 , which is commonly referred to as "stack." The respective fuel cell 9 is designed in the usual way to generate electricity from hydrogen and oxygen. Here to shows the respective fuel cell 9 an electrolyte 10 on that in the fuel cell 9 an anode side 11 from a cathode side 12 separates. On the anode side 11 of the electrolyte 10 is an anodes 13 arranged while on the cathode side 12 of the electrolyte 10 a cathode 14 is arranged.

The hydrogen storage 4 is with the anode side 11 communicatively connected, for example via a hydrogen line 15 , The hydrogen storage 4 serves to store hydrogen, preferably gaseous hydrogen. The oxygen storage 5 is with the cathode side 12 communicatively connected, for example via an oxygen line 16 , The oxygen storage 5 serves to store oxygen, preferably gaseous oxygen.

Furthermore, the device 1 according to 1 optionally with a control device 17 be equipped, on the one hand, the power lines 8th the photovoltaic device 2 and on the other hand power lines 18 the fuel cell device 3 connected to the electrodes, so with the anode 13 and with the cathode 14 the respective fuel cell 9 are electrically connected. The control device 17 is also over other power lines 19 to a basically any electrical consumer 20 connected. With this consumer 20 Without limitation of generality, this may be an electric motor, for example in a motor vehicle, or a public power grid or an electrical system of a motor vehicle or the like. The control device 17 is now configured to be at a power generation operation of the fuel cell device 3 that of the fuel cell device 3 generated electric power through the power lines 18 and 19 the respective consumer 20 provides. In addition, the control device 17 be configured so that they in a power generation operation of the photovoltaic device 2 that of the photovoltaic device 2 generated electric power through the power lines 8th and 19 the respective consumer 20 provides.

During a power generation operation of the fuel cell device 3 takes place within the respective fuel cell 9 a reaction of hydrogen and oxygen to water, during which reaction electrical current at the electrodes 13 . 14 can be tapped. The water forming in the fuel cell process collects on the cathode side 12 but in particular through the membrane 10 also to the anode side 11 reach. In the example shown, the respective fuel cell contains 9 on the anode side an anode compartment 21 passing through the anode 13 from the electrolyte 10 is disconnected. The anode 13 itself is perforated and thus permeable to hydrogen and water. Likewise, the respective fuel cell contains 9 on the cathode side a cathode compartment 22 passing through the cathode 14 of electrolytes 10 is disconnected. Also the cathode 14 is suitably perforated and thus permeable to oxygen and water. anode chamber 21 and cathode compartment 22 are expediently configured in the simple example shown here, that together can be used as a collecting space for the forming during the fuel cell process water. In the fuel cell process are in the rooms 21 . 22 the respective fuel cell 9 Hydrogen and oxygen consumed and accordingly from the stores 4 . 5 tracked. The volumes of the rooms 21 . 22 the respective fuel cell 9 as well as the memory 4 . 5 are coordinated so that the hydrogen storage 4 and the oxygen storage 5 are substantially emptied when the anode compartment 21 and the cathode compartment 22 is substantially filled by the water. The power generation operation of the fuel cell device 3 is then finished.

The control device 17 can now realize an energy storage operation, if a suff sunshine 7 is available. During this energy storage operation, the controller causes 17 a supply of the electrodes 13 . 14 the respective fuel cell 9 with at least a portion of the photovoltaic device 2 generated electric current. For this purpose, the control device 17 basically the power lines 18 the respective fuel cell 9 use. Likewise, additional power lines 23 be provided to the power of the photovoltaic device 2 the fuel cell device 3 supply. The fuel cell device 3 or the respective fuel cell 9 then serves as an electrical consumer, wherein in the respective fuel cell 9 an electrolysis is carried out. With appropriate polarity of the power supply forms on the anode side 11 Hydrogen, while on the cathode side 12 Oxygen is generated. As a result of the electrolysis, the water that is in the anode compartment becomes 21 and in the cathode compartment 22 is again decomposed into its components hydrogen and oxygen. The resulting hydrogen can in the hydrogen storage 4 be stored while the resulting oxygen in the oxygen storage 5 can be stored. Once the water is out of the rooms 21 . 22 the respective fuel cell 2 is consumed by the electrolysis, the energy storage operation can be stopped. With appropriate tuning of the volumes of the memory 4 . 5 and the rooms 21 . 22 are the memories at the end of the electrolysis process 4 . 5 filled again. The fuel cell device 3 is then ready for the production of electricity.

Core of in 1 The apparatus shown is the fuel cell device 3 containing at least one fuel cell 9 which is designed so that an electrolysis of water is feasible therein, wherein the electrodes 13 . 14 , the respective fuel cell 9 can be used, in which in normal fuel cell operation of the generated during the fuel cell process electric current can be tapped. By this construction, the fuel cell device 3 along with the hydrogen storage 4 and the oxygen storage 5 how to use a reusable energy storage. The electrical energy supplied to the electrolysis is stored in the reservoirs 4 . 5 chemically stored in the form of hydrogen and oxygen. The so chemically stored energy can be recalled if necessary fen and be converted by the fuel cell process back into electrical energy.

At the in 1 shown preferred embodiment of the device 1 becomes the electrical energy required for the electrolysis with the help of the photovoltaic device 2 provided. In principle, however, other electrical energy source for supplying the fuel cell device 3 conceivable. For example, a wind turbine, a hydropower plant or an internal combustion engine in the device 1 to be involved. Likewise, excess power of the public network can be used to convert water, such as inexpensive night-time electricity.

Particularly advantageous here is an embodiment in which the fuel cell device 3 along with the hydrogen storage 4 and the oxygen storage 5 forms a hermetically sealed media system, so that essentially always the same amount of water is decomposed by electrolysis into hydrogen and oxygen or produced by the fuel cell process of hydrogen and oxygen. The individual conversion processes are basically reversible without losses, so that this arrangement of fuel cell device 3 and hydrogen storage 4 and oxygen storage 5 no water consumed. This makes it particularly conceivable to install such a system in a low-water region, for example in a sunny desert region.

The self-contained media circuit also has the great advantage that in the media system no impurities can be incurred, for example, to damage or deterioration of the electrolyte 10 could lead. For example, the respective fuel cell 9 be filled with chemically pure water, for example with distilled water, which is quasi residue-free decomposable into its components hydrogen and oxygen. Similarly, in the back conversion of hydrogen and oxygen into water no additional harmful products, for example, the functioning of the electrolyte 10 could affect.

Referring to the 2 to 5 Below is an advantageous embodiment of a fuel cell 9 which is intended for use in a fuel cell device 3 suitable.

For example, the fuel cell has 9 a cathode-side end plate 24 which is a boundary for the cathode compartment 22 forms. In a corresponding manner, an anode-side end plate 25 be provided, which in the assembled state, the anode compartment 21 limited. For better illustration, the end faces of the end plates 24 . 25 shown here essentially transparent. The end plates 24 . 25 can basically be made of a plastic. Likewise, other materials, especially metals, conceivable. Central contains the fuel cell 9 the electrolyte 10 , The electrolyte 10 is preferential example formed by a polymer membrane. This can For example, be formed from a sulfonated tetrafluoroethylene polymer, so-called PTFE. Such PTFE membrane is known under the trade name Nafion ^®. The polymer membrane can be provided in a conventional manner on both sides with a coating in order to favor or enable the fuel cell reaction. Preferably, it is the electrolyte 10 a proton transport membrane or a polymer electrolyte membrane. Accordingly, it is then in the fuel cell 9 to a so-called PEM fuel cell, so preferably to a low-temperature fuel cell.

The cathode 14 and the anode 13 are each preferably formed by a perforated stainless steel plate. Recognizable is with both electrodes 13 . 14 a centrally arranged perforation 26 , which is about as large that the electrolyte 10 through the respective electrode 13 . 14 through a large area with the respective gas can be acted upon. The perforation 26 here is formed by a regular pattern of holes.

In the embodiment shown are several seals 27 provided, which are shown here layered. When assembled, these seals cause 27 the required sealing of anode space 21 and cathode compartment 22 to the outside and against each other and electrical insulation of the anode 13 opposite the cathode 14 , These seals 27 Kings nen as here be formed by layer-like plate elements, which may also be perforated or open centrally for gas exchange. Likewise, the seals can 27 in the form of a corresponding sealant, for example on the electrodes 13 . 14 be applied to achieve the desired seal or isolation. In the assembled state, for example, several screws penetrate 28 corresponding, unspecified passage openings in the cover plates 24 . 25 and in the electrodes 13 . 14 are formed, and are with complementary nuts 29 screwed. In principle, other attachment methods are conceivable.

At the anode-side end plate 25 and on the cathode-side end plate 24 can connections 30 be formed over the example of the anode compartment 21 with the hydrogen storage 4 or the cathode compartment 22 with the oxygen storage 5 is connectable. Likewise can over a suitable connection 30 the filling of the rooms 21 . 22 be realized with water.

The anode 13 has an anode connection 31 up, through recesses 32 through, in the cover plates 24 . 25 and in the cathode 14 are formed, is contactable. The cathode has the same way 14 a cathode connection 33 that through recesses 34 can be contacted, which in the cover plates 24 . 25 and in the anode 13 are formed.

In the 5 shown embodiment of the fuel cell 9 is different from the one in 4 shown embodiment in that the anode 13 is formed by two perforated stainless steel plates, so it is almost done twice. It has been shown that by this construction, the electric power of the fuel cell 9 can be significantly increased.

When mounted, the respective electrode is located 13 . 14 essentially directly on the electrolyte 10 at.

The device 1 according to 1 can be operated in an energy storage operation, in which of the photovoltaic device 2 generated electric power at least partially in the fuel cell device 3 is used for electrolysis. During this energy storage operation, water is accumulated in the anode compartment 21 and in the cathode compartment 22 is converted into hydrogen and oxygen and become the hydrogen storage 4 with hydrogen and the oxygen storage 5 filled with oxygen.

Furthermore, can be with the device 1 realize a Stromabgabebetrieb in which the fuel cell device 3 in the respective fuel cell 9 realized a fuel cell process in which in the usual way, hydrogen is converted with oxygen into water and electricity. The anode-side consumed hydrogen is thereby from the hydrogen storage 4 refilled, while the cathode side consumed oxygen from the oxygen storage 5 is tracked.

Furthermore, the device 1 in a specific embodiment, be configured to supply electrical power either exclusively via the photovoltaic device 2 or exclusively via the fuel cell device 3 or both about the photovoltaic device 2 as well as via the fuel cell device 3 provides. The provision of the electrical current may be based on the availability of the electromagnetic solar radiation and / or the current power consumption of the respective consumer 20 depend. For example, it can be provided, with a low power requirement this exclusively by the photovoltaic device 2 to avoid losses of efficiency in the electrolysis and in the fuel cell process. If at such a low power requirement, excess power from the photo voltaikeinrichtung 2 can be generated, this in the fuel cell device 2 be used for electrolysis. Furthermore, the fuel cell device 3 be switched on for power generation, if that of the photovoltaic device 2 Generated electrical power is no longer sufficient to meet the current power needs of each consumer 20 cover up. Likewise, the fuel cell device 3 used for power generation when the photovoltaic device 2 due to lack of solar radiation is not able to do so.

The device 1 For example, it can be used in a motor vehicle to realize a hybrid electric drive in the vehicle. The vehicle may be a conventional vehicle suitable for the transport of persons and / or goods or else a model vehicle or toy vehicle. In the latter case, a simple fuel cell is enough 9 and a simple solar cell 6 out to operate a small electric motor of the vehicle. It is also conceivable to equip a power plant with at least one such device in order to generate electrical energy.

Claims (13)

Device for converting, storing and emitting energy, - with a photovoltaic device ( 2 ), the at least one solar cell ( 6 ) for the conversion of electromagnetic solar radiation ( 7 ) in electrical power, - with a fuel cell device ( 3 ), the at least one fuel cell ( 9 ) for generating electricity of hydrogen and oxygen, comprising an electrolyte ( 10 ) having an anode side ( 11 ) with an anode ( 13 ) from a cathode side ( 12 ) with a cathode ( 14 ), - with a hydrogen storage ( 4 ) connected to the anode side ( 11 ) is communicatively connected, - with an oxygen storage ( 5 ) connected to the cathode side ( 12 ) is communicatively connected, - wherein the device ( 1 ) is configured to carry out an energy storage operation, in which the photovoltaic device ( 2 ) electrically to the anode ( 13 ) and to the cathode ( 14 ) of the respective fuel cell ( 9 ) is connected such that at least with a part of the of the photovoltaic device ( 2 ) generated electric current water, located on the anode side ( 11 ) and on the cathode side ( 12 ) of the respective fuel cell ( 9 ) by electrolysis on the anode side ( 11 ) in hydrogen and on the cathode side ( 12 ) is converted into oxygen. Device according to claim 1, characterized in that - the respective anode ( 13 ) has a perforated stainless steel plate directly on the electrolyte ( 10 ), and / or - that the respective cathode ( 14 ) has a perforated stainless steel plate directly on the electrolyte ( 10 ) is present. Device according to claim 1 or 2, characterized in that the respective anode ( 13 ) has at least two parallel perforated stainless steel plates, of which only one on the electrolyte ( 10 ) is present. Device according to one of claims 1 to 3, characterized in that - the respective anode side ( 1 ) one through the anode ( 13 ) from the electrolyte ( 10 ) separate anode space ( 21 ) having a predetermined volume and communicating with the hydrogen storage ( 4 ) is communicatively connected, - that the respective cathode side ( 12 ) one through the cathode ( 14 ) from the electrolyte ( 10 ) separate cathode space ( 22 ), which has a predetermined volume and which is connected to the oxygen storage ( 5 ) is communicatively connected, - that the volumes of the respective anode space ( 21 ), of the respective cathode compartment ( 22 ), the hydrogen storage ( 4 ) and the oxygen storage ( 5 ) are matched to one another such that by the electrolysis of a respective anode space ( 21 ) and the respective cathode compartment ( 22 ) auffüllenden amount of water on the anode side of the hydrogen storage ( 4 ) and on the cathode side the oxygen storage ( 5 ). Device according to one of claims 1 to 4, characterized in that as electrolyte ( 10 ) is a polymer membrane, for example of a sulfonated tetrafluoroethylene polymer (PTFP), which may be provided on both sides with a catalytically active coating. Fuel cell device, the at least one fuel cell ( 9 ) for the generation of electric current from hydrogen and oxygen with an electrolyte ( 10 ), which in the respective fuel cell ( 9 ) an anode side ( 11 ) with an anode ( 13 ) from a cathode side ( 12 ) with a cathode ( 14 ), characterized by the use of the fuel cell device ( 3 ) for the conversion of water, which on the respective anode side ( 11 ) and on the respective cathode side ( 12 ) of the respective fuel cell ( 9 ), by electrolysis on the anode side in hydrogen and on the cathode side in oxygen. Fuel cell device according to claim 6, characterized by the characterizing features of at least one of claims 2 to 5th Method for operating a device for Conversion, storage and delivery of energy, in particular according to one of claims 1 to 5, - in which, during an energy storage operation, at least part of the energy produced by a photovoltaic device ( 2 ) of the device ( 1 ) generated electric current for the application of anode ( 13 ) and cathode ( 14 ) at least one fuel cell ( 9 ) a fuel cell device ( 3 ) of the device ( 1 ) is used by electrolysis on an anode side ( 11 ) of the respective fuel cell ( 9 ) Hydrogen and on a cathode side ( 12 ) of the respective fuel cell ( 9 ) To produce oxygen, - in which the hydrogen in a hydrogen storage ( 4 ), - in which the oxygen in an oxygen storage ( 5 ) is stored. A method according to claim 8, characterized in that - during a Stromabgabebetriebs the fuel cell device ( 3 ) in the respective fuel cell ( 9 ) converts the hydrogen and the oxygen to water and electric current, - that the hydrogen from the hydrogen storage ( 4 ) to the anode side ( 11 ) - that the oxygen from the oxygen storage ( 5 ) to the cathode side ( 12 ). Method according to claim 8 or 9, characterized in that the device ( 1 ) electrical current as a function of the power requirement and / or as a function of the availability of electromagnetic solar radiation with the photovoltaic device ( 2 ) and / or with the fuel cell device ( 3 ). A method according to claim 10, characterized in that at a low power consumption of this exclusively by the photovoltaic device ( 2 ), wherein excess current in the fuel cell device ( 3 ) is used for electrolysis. Vehicle with a device ( 1 ) according to one of claims 1 to 5. Power plant with at least one device ( 1 ) according to one of claims 1 to 5.