WO2006029688A1

WO2006029688A1 - Local power supplied vending machine

Info

Publication number: WO2006029688A1
Application number: PCT/EP2005/009002
Authority: WO
Inventors: Jürgen Utschig; Josef Bayer
Original assignee: Sielaff Gmbh & Co. Kg Automatenbau
Priority date: 2004-09-14
Filing date: 2005-08-19
Publication date: 2006-03-23

Abstract

The invention relates to a vending machine provided with a local power supply. According to said invention, the local power supply comprises at least one fuel cell. The use of the fuel cell for supplying power to the vending machine is also disclosed.

Description

Vending machine with local energy supply

Description

The invention relates to a vending machine with local power supply and a use.

Vending machines, which are often referred to in the relevant literature as a self-seller, are generally known in a variety of different configurations and variants, so that their detailed structure and operation will not be discussed in more detail below. For the general background of such vending machines, reference is made to German laid-open specification DE 296 20 666 A1 and German patent specification DE 35 00 855 C2. Such vending machine devices require an energy supply for their function, for example for dispensing the goods, for controlling, for input, for cooling, for lighting, etc.

Depending on the application and installation site, different variants are known for the power supply of the vending machine, which are briefly described below:

The simplest form of energy supply is the network operation in which the vending machine is connected to a mains voltage. Above all, vending machines which are installed in the outer area, but also sometimes Tomatoes placed indoors within a closed building often do not have a mains connection. For the energy supply of the vending machine, a local energy supply is required here.

In the simplest case, a local power supply consists of a conventional, non-rechargeable battery. This solution is not very pragmatic, since the battery is discharged very quickly, especially in the case of frequent use of the vending machine and in vending machines which, due to their function, have a very high energy consumption. The non-rechargeable batteries would then have to be exchanged very frequently, which however requires a local service. This is a very costly solution.

In addition, rechargeable batteries, known as rechargeable batteries or short rechargeable batteries, are used for the local energy supply. However, these batteries must be recharged on a case-by-case basis, for example, by connecting to a power outlet. It is also problematic here that such a network connection is very often not available. Modern charging machines are equipped with photovoltaic elements (solar cells) for charging the rechargeable batteries, in which the energy is obtained by means of solar technology. However, when using solar cells for the supplementary energy supply, it must be remembered that they only supply electricity as long as they are also exposed to solar radiation or any other artificial radiation. Vending machines, however, are very often placed on shaded places.

The present invention is based on the object, another power supply for a vending machine provide. In particular, an improved local ^" power supply for a vending machine is to be provided.

According to the invention, this object is achieved by a vending machine with the features of claim 1 and by a use having the features of claim 13. Demge¬ is provided according to:

A vending machine with local energy supply, in which the local energy supply contains at least one fuel cell. (Claim 1)

A use of a fuel cell for Energieversor¬ supply of a vending machine. (Claim 13)

In complete departure from previous solutions for the energy supply of vending machines, the present invention is based on the idea of providing a fuel cell for this purpose. Fuel cells have been well known for many years and have the advantage of very high electrical efficiency with low emissions. Such fuel cells are particularly suitable for mobile, but also for stationary applications. Since pure water is produced as a reaction product in the fuel cell, the fuel cell is also a very environmentally friendly energy supply, which is very attractive in particular for future applications.

Advantageous embodiments and further developments of the invention will become apparent from the further subclaims and the description with reference to the drawing.

In a very advantageous embodiment, the fuel cell is a so-called polymer electrolyte membrane Fuel cell or short a PEM fuel cell vorgese¬ hen. PEM fuel cells are uncomplicated in their handling and have a high power density with low weight. Instead of pure oxygen, the PEM fuel cell requires only atmospheric oxygen as the reaction gas. The hydrogen for the reaction is generated by means of a reformer. The electrolyte used here is in particular a proton-conducting polymer-electrolyte-solid membrane of sulfonated polymer. Since the power output of a PEM fuel cell can be regulated with very great dynamics, it is outstandingly suitable for mobile use and for decentralized energy supply, as is required in the vending machine. Another advantage of PEM fuel cells is their great potential for mass production, since the cost of a cell block of a PEM fuel cell is in the range of less than 100 euros / kilowatt.

In an additional or alternative embodiment, the fuel cell may be formed as an alkaline fuel cell or short as an AFC fuel cell. AFC fuel cells are the only fuel cells known today which require purest oxygen and purest hydrogen for energy conversion since even the slightest impurities could destroy the fuel cell. If ambient air is used instead of the oxygen, the carbon dioxide present in the ambient air must be completely removed before the actual reaction in order to avoid a "poisoning" of the electrolyte and thus a deterioration of its function. The electrolyte used here is mainly potassium hydroxide solution. Due to the fact that AFC fuel cells can be produced relatively cheaply even in very small quantities, they are particularly well suited for use in vending machines. Another advantage of AFC fuel cells is their low operating temperature. In an additional or alternative embodiment, the fuel cell may also be designed as a solid oxide fuel cell or, for short, as an SOFC fuel cell. Such SOFC fuel cells are particularly suitable for mobile applications, for example for replacement in the vending machine or in addition to an accumulator and / or disposable battery present in the vending machine. The SOFC fuel cell works with atmospheric oxygen and hydrogen. As a fuel, for example, Erd- / Bio- or coal gas wer¬ used, from which the hydrogen is generated by means of a reformer. Alternatively, gasoline can be used, but before the fuel cell a technically simple reformer and desulfurization must be supplied. However, the operating temperature is Be¬ relatively high and is in the range of 800 C ⁰ - 1000 C. This high temperature ⁰ allows a cell internal part reforming of natural gas to hydrogen. The cost of hydrogen production thus drops considerably.

In an additional or alternative embodiment, a direct methanol fuel cell or DMFC fuel cell may be used as the fuel cell. Such DMFC fuel cells are particularly suitable for small, portable applications and for local, decentralized power supplies. The DMFC fuel cell is the only fuel cell that does not work with hydrogen, but with methanol as the production medium. This methanol is much easier to store than other fuel media, such as hydrogen. A reformer for conversion can be dispensed with here, since the fuel cell itself converts methanol into hydrogen protons, free electrons and carbon dioxide. Due to the missing reformer, the DMFC fuel cell is best suited for use in decentralized devices, such as in a vending machine, as it comes closest to the goal of the simplest possible source of energy. When Electrolyte is used here a proton-conducting polymer electrolyte membrane.

In addition to the fuel cells just mentioned, of course, other types of fuel cells, such as, for example, the known from Kraftwärmekopp¬ ment PAFC fuel cell (PAFC = phosphoric acid fuel cell) or the molten carbonate fuel cell (MCFC fuel cell, MCFC = molten carbonate fuel cell ) in question.

In a typical embodiment, the local energy supply has a tank or a container in which the fuel for the fuel cell is stored. As fuel, for example, liquid hydrogen can be used. Alternative fuels include methanol, natural gas, gasoline, biogas, coal gas and carbon monoxide.

In particular, when using not high purity hydrogen as fuel, this must be generated only from the fuel. For this purpose, a reformer is arranged between the tank and the fuel cell, to which the fuel is supplied from the tank. By way of example, the reformer generates pure hydrogen by catalysis.

According to the laws of electrochemistry, a single fuel cell supplies only an electrical voltage of about 1 volt. Since this is not sufficient for most applications in a vending machine, several individual fuel cells are preferably connected in series one behind the other in order to achieve higher voltages. Such a stack of fuel cells is also referred to as a stack. For example, a fuel cell application for the local power supply in a vending machine has at least twelve individual fuel cells to provide a supply Voltage of about 12 volts for supplying the vending machine to provide ten. In order to provide a higher supply voltage suitable for vending machines, the fuel cell arrangement preferably has more than twelve such individual fuel cells, for example fifteen individual fuel cells. In an additional or alternative embodiment, the individual fuel cells or fuel cell stacks can also be arranged parallel to one another, in order thereby to provide a higher current.

In a very advantageous embodiment, in addition to the fuel cell, a further, supplementary energy supply can be provided. For example, a photovoltaic element which supplies current and / or voltage for supplying energy to the vending machine from natural or artificial light is suitable as a supplementary energy supply. Additionally or alternatively, the supplementary energy supply can also contain a rechargeable battery (rechargeable battery) and / or a non-rechargeable battery (monobloc battery). In a further embodiment, the supplementary energy supply can also be a power supply network to which the vending machine is connected. Depending on the application, the local energy supply formed as a fuel cell and the supplementary energy supplies can preferably also be linked to one another, so that overall an intelligent energy management for the vending machine can be provided.

In an advantageous embodiment, at least one current / voltage regulator arrangement is provided between the supply outlet of the fuel cells and a load. By means of this regulator, the supply current provided by the fuel cells on the output side or the supply voltage provided can be set to a constant current or adjust to a constant voltage value. This ensures that unwanted deviations, such as voltage and / or current peaks, are corrected by means of the voltage / current regulator.

In an advantageous embodiment, a measuring device is provided which detects the state of the electrolyte within the fuel cell. Furthermore, a further measuring device can be provided, which detects the filling level of the tank. By means of a control device provided for this purpose, the values recorded by the measuring devices, that is to say the fill level of the tank, can be evaluated.

The invention will be described below with reference to the exemplary embodiment given in the single FIGURE of the drawing: It shows:

1 shows a block diagram for the representation of a vending machine with a local energy supply according to the invention.

In Fig. 1 is denoted by reference numeral 1 Ver¬ the automatic vending machine according to the invention. The vending machine 1 has a local power supply 2, which is connected via a controllable switch 3 with a consumer (load) 4. The controllable switch 3 can be designed as an actuating element of the vending machine 1 or be connected to such. Upon actuation of this actuating element, the controllable switch 3 is closed and a supply current 12 is supplied to the consumer 4. The consumer 4 designates any ohmic and / or capacitive consumer and can be, for example, the dispensing mechanism, the lighting, the cooling, etc. of the vending machine 1. The remaining functional components and elements of the automatic vending machine 1, for example the goods receiving device, the goods dispensing device, input keyboard, Münzauf¬ acceptance and coin dispensing device, display (Dis¬ play), cooling, lighting, etc. and the like are for better clarity not shown in FIG. 1.

According to the invention, the local energy supply 2 has a fuel cell arrangement 5. In the present embodiment, the fuel cell arrangement 5 has fifteen individual fuel cells β, which are arranged in series with one another. On the output side, the fuel cell arrangement 5 generates a supply potential V 1 and a supply current II. In the example shown, that is fifteen fuel cells 6, the supply voltage V 1 is approximately 15 volts.

Between the actuating element 3 and the fuel cell arrangement 5, a current-voltage regulator 7 is also provided. The current-voltage regulator 7 generates from the supply current Il and the supply voltage Vl a regulated supply current II or a regulated supply voltage V2, which can be supplied to the load 4.

The local energy supply 2 also has a tank 8 or another container which serves to receive the fuel. Between the tank 8 and the fuel line assembly 5, a reformer 9 is further arranged, to which the fuel 10 is supplied from the tank 8. Contains the tank 8 as fuel hydrogen, can be advantageously dispensed with the reformer. The reformer 9 generates on the output side from the fuel 10 hydrogen 11, which is the fuel cell assembly 5 is supplied. In addition, the fuel cell assembly 5 is also ambient air 12, in which thus contains oxygen, fed. Of course, instead of using ambient air 12, it is also possible to use ^" purest oxygen stored in a dedicated tank (not shown in FIG. 1).

Since the structure of a fuel cell is generally known, the description of its detailed structure is omitted. In the following, however, the mode of operation of a fuel cell will be briefly described, since this is essential in particular for selecting the most suitable fuel cell type for the vending machine 1.

Fuel cells convert chemical energy directly into electricity. The operating principle here is the reverse reaction of the known electrolysis, in which water and oxygen are produced from water.

In the reaction taking place in the fuel cell, hydrogen gas splits at the catalytically active layer of the anode into protons (H +) and electrons (e-). The protons pass through the proton-conducting electrolyte to the cathode of the fuel cell, while the electrons perform electrical work in the external circuit and subsequently reach the cathode. There, the protons and electrons react with oxygen to form water. Between Ano¬ de and cathode creates a voltage that is about 1 volt at rest.

At the catalyst-coated anode, the hydrogen molecules split into their two hydrogen atoms. Each hydrogen atom gives off an electron which migrates to the cathode via an electrical conductor. It flows through an electric current that can be used. This leaves behind positively charged hydrogen ions (H +). On the cathode side te oxygen molecules under the influence of Kataly¬ in their two oxygen atoms. These then each take on two electrons, whereby negatively charged Sau¬ erstoffionen arise. The hydrogen ions migrate from the anode side through the electrolyte which passes through positive hydrogen particles onto the cathode side. There they combine with the negatively charged oxygen ions to form water.

This basic principle of the reaction of hydrogen with oxygen applies equally to all fuel cells. The implementation, however, looks very different for the different types of fuel cells. Depending on the electrolyte used, different ions are exchanged. Instead of pure oxygen, often only ambient air containing oxygen is used. In addition to hydrogen, methanol, natural gas or gasoline can be used as fuels. However, natural gas or gasoline must be converted into hydrogen and carbon dioxide in a specially designed reformer. The most important distinguishing feature of the various fuel cells is the electrolyte, which keeps the two reaction partners away from one another and at the same time ensures an exchange of ions between the anode and the cathode. Such an electrolyte may for example be a membrane which separates hydrogen or oxygen, but allows hydrogen ions to pass through. However, there are also electrolytes of liquid potassium hydroxide, molten salts or solid ceramic materials. The type of exchanged ions depends on this electrolyte, as well as the working temperature with which the fuel cell is operated.

In addition to the overall performance, the efficiency is the most important characteristic of a fuel cell. It describes the relationship between inserted and usable energy, ie the E- energy yield of the fuel cell. With today's fuel cells, efficiencies of up to 70% can be achieved, depending on the fuel cell type used.

Although the present invention has been described above with reference to a preferred embodiment, it is not limited thereto, but modifiable in many ways.

In the exemplary embodiment, only a single consumer has been illustrated. It goes without saying that a vending machine typically has a multiplicity of consumers, which, for the sake of simplicity, however, were not illustrated in the exemplary embodiment.

The construction of a fuel cell arrangement with 15 individual fuel cells is also merely an example.

Instead of using a tank or a container for the fuel (hydrogen), it can also be provided that it is generated in the vending machine, for example by means of solar energy, although it is clear that this represents a technically very complicated implementation. It would also be conceivable for this generation of the fuel to be produced in addition to the fuel in the tank and thus to serve as a supplementary fuel supply.

The vending machines according to the invention can be embodied in a multiplicity of different applications, for example as cigarette vending machines, vending machines, machines for dispensing prepaid cards or telephone cards, money changers, machines for issuing parking tickets, city maps, hygiene articles and like. Reference list

1 vending machine

2 local power supply

3 controllable switch, actuator

4 load, consumer

5 fuel cell assembly

6 single fuel cell

7 current / voltage regulator

8 tank, container

9 reformers

10 fuel

11 hydrogen

12 oxygen

V1, V2 supply voltages II, 12 supply currents GND reference potential

Claims

P at ent sp r es

1. Vending machine (1) with local power supply (2), since you know ch ch t that the local power supply (2) contains at least one fuel cell (5).

2. The vending machine according to claim 1, characterized in that a PEM fuel cell is provided as the fuel cell (5).

3. Vending machine according to at least one of the preceding claims, since you ch el te ch e that tne fuel cell (5) is an AFC fuel cell vorge¬ seen.

4. Vending machine according to at least one of the preceding claims, since you ch el te ch e t that, as a fuel cell (5) an SOFC fuel cell vor¬ seen.

5. vending machine according to at least one of the preceding claims, since you ch e r e ch e e s that e e that a fuel cell (5) is a DMFC fuel cell vor¬ seen.

6. Vending machine according to at least one of the preceding claims, characterized in that a tank (8) is provided, in which the fuel is stored ge.

7. Vending machine according to claim 6, characterized in that a reformer (9) is arranged between the tank (8) and the fuel cell (5), on the input side the fuel (10) from the tank can be fed, which converts the supplied fuel (10) into hydrogen and the output side provides the generated hydrogen (11) for the fuel cell (5).

8. vending machine according to at least one of the preceding claims, since dur ch ge chi t egg that several individual fuel cells (5) are provided, which are arranged in parallel with respect to their supply outputs and / or connected in series.

9. Vending machine according to claim 1, characterized in that the local energy supply (2) has at least one supplementary energy supply.

10. Vending machine according to claim 9, characterized in that the supplementary energy supply has at least one photovoltaic element and / or at least one rechargeable battery (accumulator) and / or at least one disposable battery.

11. Vending machine according to at least one of the preceding claims, characterized in that a current regulator and / or a voltage regulator (7) is provided, which is connected between a supply output of the combustion Substance cell (5) and a load (4) is arranged and the supply of the fuel cell (5) of the load (4) supply current (II) and / or supply voltage (Vl) to a constant current or voltage value (12 , V2).

12. Vending machine according to claim 1, characterized in that a measuring device is provided which detects the state of the electrolyte of the fuel cell (5) and / or detects the filling level of the tank (8) and that a Steuervorrich¬ device is provided which evaluates the measures measured by the measuring device senen values.

13. Use of a fuel cell (5) for Energieversor¬ supply of a vending machine (1).