DE102018130845A1 - Container for a liquid for use as a water tank of an electrolyzer, electrolyzer with the container as a water tank - Google Patents

Abstract

The invention relates to a container (100) for a liquid for use as a water tank of an electrolyser (200) with a cavity (110) enclosed by an at least partially gas-tight outer wall (101) for receiving the liquid and at least one outer filling opening (160) for filling the liquid from an environment of the container (100) into the cavity (110) and at least one flow opening (102) for dispensing liquid from the cavity (110) to an electrolysis cell (210) of the electrolyzer (200) and at least one return opening (103 ) for the admission of other components of the electrolyzer (200) during operation with a dispensing period of periodically dispensed liquid and continuously dispensed gas and dispensed liquid into the cavity (110) and at least one filling chamber (130). The filling space (130) is connected in a liquid-conducting manner on its upper side to the outer filling opening (160) and in a liquid-conducting manner on its underside opposite the upper side via an inner filling opening (165) to the cavity (110) and via a perpendicular to an opening plane (OE) of the inner filling opening (165) oriented height (H) of the filling space is completely enclosed on the circumference by a jacket wall (170) surrounding an opening surface normal of the inner filling opening (165). The jacket wall (170) is gas-tight above the opening level (OE). The opening level (OE) divides the cavity (110) outside the filling space (130) into a buffer space (140) with a buffer volume above the opening level (OE) and a storage space (125) below the opening level (OE) for receiving the liquid, whereby the buffer space (140) is designed to completely accommodate a volume of the liquid dispensed within a dispensing period.

Description

Technical field

The invention relates to a container for a liquid for use as a water tank of an electrolyser with a cavity enclosed by an at least partially gas-tight outer wall for receiving the liquid and at least one outer filling opening for filling the liquid from an environment of the container into the cavity and at least one flow opening for Dispensing liquid from the cavity to an electrolysis cell of the electrolyzer and at least one return opening for the admission of liquid periodically dispensed and continuously dispensed gas and dispensed liquid into the cavity and at least one filling chamber by other components of the electrolyzer during operation with a dispensing period. The top of the filling chamber is connected in a liquid-conducting manner to the outer filling opening and in a liquid-conducting manner on its underside opposite the top via an inner filling opening to the cavity. The filling space is completely enclosed on the circumference over a height oriented perpendicular to an opening plane of the inner filling opening by a jacket wall surrounding an opening surface normal of the inner filling opening.

The invention further relates to an electrolyzer for the electrolysis of water with a container according to the invention as a water tank.

State of the art

Various containers for electrolysers for holding liquids are known from the prior art. With some electrolysers, it is necessary that their containers are not completely filled with liquid, but only up to a target fill level at which a gas-filled buffer volume remains free inside the container. The gas-filled buffer space is used, for example, to take in water from a cathode side of the electrolyser, which is connected to the tank in a fluid-conducting manner via a separating tank, and which is collected in the separating tank as a liquid volume of a liquid at intervals without the tank overflowing.

In order to prevent the container from being filled beyond the desired fill level, a desired fill level marking can be attached to the container, but this can easily be overlooked by a human filler. Alternatively, the container can be filled automatically up to a desired fill level, but this requires a measuring and control device and a separate supply system for the liquid.

The electrolyzer, which splits water into hydrogen and oxygen by means of an electric current, can be, for example, a proton exchange membrane electrolyzer (PEM electrolyzer), in which the electrolysis takes place on a proton-permeable polymer membrane which divides an electrolysis cell into an anode space and a cathode space. The water for operating a PEM electrolyser is mostly ultrapure water. A PEM electrolyser is described, for example, in the publication DE19653034A1 disclosed.

In PEM electrolysers, the electrolysis cell containing the proton exchange membrane is usually connected to an anode side (oxygen side) via two water pipes on a water tank. One connection is used to supply water to the electrolysis cell and the other to discharge oxygen and water from the electrolysis cell to the water tank. Depending on the design of the electrolyzer, it may be necessary to integrate a pump into this circuit. This is how oxygen gas gets into the water tank, which must escape or degas from it.

The cathode compartment (hydrogen side) of the electrolytic cell usually has only one connection, namely an outlet with hydrogen gas and water as the outlet media. In addition to the hydrogen gas, water also enters the cathode compartment and thus also to its outlet, since the polymer membrane of the PEM electrolyser is conductive for H ₃ O ⁺ ions, which are converted to H ₂ and H ₂ O at the cathode with electron transfer.

This separating water, which arises on the cathode side, is usually separated from the hydrogen gas in a separating container and is usually collected there. Since this water is also ultrapure water, it can be reused for further use and pumped back into the water tank.

For practical reasons, the water is usually pumped back into the water tank periodically. This pumping back is usually triggered by a level sensor, which triggers the pump back process at a certain water level in the separating tank.

1. A) Die Bereitstellung von Wasser zur Versorgung der Elektrolysezelle mit Wasser;
2. B) die Abgabe des Sauerstoffgases an eine Umgebung;
3. C) die Aufnahme des Abscheidewassers aus dem Abscheidebehälter;
4. D) Aufnahme von Wasser von außen über eine Einfüllöffnung zum Befüllen oder Nachfüllen.

The water tank has the following functions:

1. A) The provision of water to supply the electrolysis cell with water;
2. B) the release of the oxygen gas to an environment;
3. C) the collection of the separating water from the separating container;
4. D) Absorption of water from the outside via a filling opening for filling or refilling.

Since the water volume pumped back at intervals from the separation tank requires a free air volume in the water tank, which it can displace, the liquid tank has so far been provided with a maximum fill level marking for trouble-free use, and may only be filled with water up to this by the user. If the user does not adhere to the maximum fill level and fills the liquid tank beyond this, overflowing of the water tank or overpressure in the water tank can occur when the separating water is pumped back. An overpressure in the water tank can damage a degassing membrane of the water tank, a pump for returning the water from the separating tank or other components of the electrolyser or it can hinder the return of the water from the residual water tank. This interferes with the normal functioning of the electrolyser, or it can even lead to a defect in the electrolyser.

Since the user always needs his attention and, in the case of an inexperienced user, the level mark must be recognized so that he does not exceed the level mark marked when filling or filling the liquid tank, some users feel that water is higher than the level mark or even is filled up to the edge of the filling opening. Depending on the fill level of the separator tank, this can lead to the problems mentioned, since a full water tank cannot hold any additional water volume from the separator tank.

Even when not in use, the polymer membrane of a PEM electrolyser is usually kept moist so that it is not damaged by drying out. This usually means that there is water in the water tank during transport and storage of the electrolyser, which should not leak even if the storage or transport position is incorrect. Current electrolysers therefore often require a separate closure or a waterproof membrane, which is also referred to as a degassing membrane, to close a degassing opening in the water tank during storage or transport.

Up to now, electrolysers have mainly been used for clean gas production in industry, for laboratory applications or as a hydrogen manufacturer for energy storage. For a few years now, scientific knowledge has also given rise to another area of application in the medical, home care and health sectors. The requirements for electrolysers are different here than in industry. A decisive factor in the new application areas is in particular a compact design, quiet operation and simple operation.

Technical task

The object of the invention is to provide an inexpensive, compact, quiet and user-friendly and reliable liquid container that can be used as a water tank for an electrolyzer. Furthermore, it is an object of the invention to provide an inexpensive, compact, quiet, reliable and user-friendly water electrolyzer.

Technical solution

The object of the present invention provides a container which solves the technical problem according to the features of claim 1. The object is also achieved by an electrolyzer according to claim 11. Advantageous refinements result from the dependent claims.

Description of the execution types

1. a) einen von einer zumindest abschnittsweise gasdichten Außenwand umschlossenen Hohlraum zur Aufnahme der Flüssigkeit und
2. b) zumindest eine äußere Einfüllöffnung zum Einfüllen der Flüssigkeit aus einer Umgebung des Behälters in den Hohlraum und
3. c) zumindest einer Vorlauföffnung zur Abgabe von Flüssigkeit aus dem Hohlraum an eine Elektrolysezelle des Elektrolyseurs und
4. d) zumindest einer Rücklauföffnung zum Einlass von von anderen Komponenten des Elektrolyseurs während des Betriebes mit einer Abgabeperiode periodisch abgegebener Flüssigkeit und kontinuierlich abgegebenem Gas und abgegebener Flüssigkeit in den Hohlraum und
5. e) zumindest einen Einfüllraum.

A container according to the invention for a liquid for use as a water tank of an electrolyzer comprises:

1. a) a cavity enclosed by an at least partially gas-tight outer wall for receiving the liquid and
2. b) at least one outer filling opening for filling the liquid from an environment of the container into the cavity and
3. c) at least one flow opening for dispensing liquid from the cavity to an electrolysis cell of the electrolyzer and
4. d) at least one return opening for the inlet of liquid and continuously discharged gas and liquid released periodically by liquid and continuously released liquid by other components of the electrolyzer during operation with a discharge period
5. e) at least one filling space.

The liquid dispensed periodically with a dispensing period can in particular be water dispensed from a separating container of the electrolyzer. The continuously dispensed gas and dispensed liquid can in particular be from an anode compartment of an electrolysis cell of the electrolyzer acted oxygen or water released.

The top of the filling chamber is connected in a liquid-conducting manner to the outer filling opening and in a liquid-conducting manner on its underside opposite the top via an inner filling opening to the cavity.

The filling space is completely enclosed on the circumference by a jacket wall that runs around an opening surface normal of the inner filling opening and is completely enclosed on the circumference, perpendicular to an opening plane of the inner filling opening. The jacket wall can be formed at least partially by the outer wall of the container. Furthermore, the jacket wall can be at least substantially perpendicular or also at a different angle on the opening plane of the inner fill opening.

Preferably, the jacket wall above the opening level of the inner filling opening is gas-tight, and the opening level divides the cavity outside the filling space into a buffer space with a buffer volume above the opening level and a storage space below the opening level for receiving the liquid.

The buffer space is preferably designed at least for the complete absorption of a volume of the liquid dispensed within a dispensing period. The buffer space is preferably designed so large that, in addition to the separation volume of a separation liquid from the separation container, it can hold a filling volume of liquid in the filling space. This ensures that the container does not overflow or absorb overpressure, which can result in damage if the filling chamber is simultaneously filled with liquid, the filling opening is closed, the separation volume is released from the separation container to the container, oxygen reaches the filling volume from the electrolysis cell, and the cover of the filling opening has no possibility of degassing.

The size of the buffer space is additionally determined by the design and position of the degassing opening described below, e.g. a degassing opening with a degassing membrane and a pressure relief valve arranged in series therewith. If, for example, parts of the degassing opening protrude into the buffer space, it may be necessary for the resulting part level and the resulting overlying volume to reach the inner wall of the housing from the already calculated buffer volume from e.g. Filling volume and separation volume should be added. In addition, the calculated buffer volume should be viewed as a minimum volume, since the customer should tolerate an increase in this area by possible factors such as inclination of the device in certain areas.

The outer wall is preferably at least liquid-tight. For the purposes of the invention, “liquid-tight” means that under typical conditions of use, for example in a temperature range from 10 ° C. to 50 ° C., in particular 20 ° C. to 30 ° C., at least during a typical operating period of the container, for example during a day, in particular during a week, no liquid will pass through a liquid-tight wall.

The liquid can be water, for example, in particular ultrapure water with an electrical conductivity of, for example, less than 5 µS / cm, preferably less than 1 µS / cm. The use of ultrapure water ensures that the electrolyser is not damaged by too high a salt content or other impurities in the water.

For the purposes of the invention, “gas-tight” means that under typical conditions of use, for example in the aforementioned temperature ranges at a gas overpressure of up to 5 mbar, in particular up to 50 mbar, at least during a typical filling period of liquid into the cavity, for example during a Duration of one minute, at most a volume of a gas, in particular nitrogen and / or oxygen, which is negligible compared to the buffer volume, passes through a gas-tight wall. For example, a proportion less than 5%, in particular less than 1%, is negligible.

Terms such as "top", "bottom" or "side" refer to an orientation of the container in a gravitational field when used as intended. In particular, the outer filling opening is above the filling space and the buffer space, and the filling space and the buffer space are above the storage space. Furthermore, the opening level of the inner filling opening is oriented essentially horizontally when the container is oriented as intended.

Because the jacket wall is gas-tight, a gas located in the buffer space, especially if the portions of the outer wall delimiting the buffer space are gas-tight except for the degassing opening, cannot flow out of the buffer space when filling liquid through the filling opening and the filling space into the storage space escape as it is down from the liquid in the storage space, up from the outer wall and to the sides from the outer wall and the Cladding wall is included. As a result, the buffer space remains essentially liquid-free even if the liquid is filled into the container beyond the opening level of the inner filling opening, in particular until the filling space is completely filled.

Regardless of how far the storage space and possibly the filling space are filled with liquid, the buffer space that remains liquid-free can accommodate a separation volume of a separation liquid from the separation container without the risk of overflow or excess pressure in the container. Overpressure is prevented in particular by the degassing opening in the area of the buffer space. For reliable operation, an operator does not have to take care to fill the container only up to a predetermined partial level. As a result, the container can be used in a particularly user-friendly and reliable manner as a water tank for the electrolyzer. This also means a more compact design and better integration into the electrolyser, since an inspection window or riser that is visible from the outside is not needed for the maximum level indicator.

The container can comprise at least one further gas-permeable degassing opening, for example one, two or three further degassing openings, for releasing a gas, in particular oxygen, from the cavity to the surroundings of the container. The at least one degassing opening and / or the at least one further degassing opening is preferably designed to allow a gas stream to pass that is at least as large as the sum averaged over a delivery period of a gas stream released on the anode side of the electrolytic cell and one with the separating liquid Container supplied fluid flow.

The at least one degassing opening and / or further degassing opening advantageously prevents gas, for example oxygen produced by an electrolyser, from accumulating in the cavity, as a result of which an overpressure could arise which could result in an uncontrolled escape of liquid or damage or malfunction of the container or of the electrolyser. In addition, the at least one degassing opening and / or further degassing opening, together with the buffer space, prevents recirculating liquid from the separating container from leading to overflow or overpressure.

The at least one degassing opening can be arranged in a section of the outer wall delimiting the buffer space. This ensures that gas released during operation of the electrolyzer, for example oxygen produced on the anode side of the electrolytic cell, is not trapped in the buffer space. The degassing opening, in particular a degassing membrane for the liquid-tight closure of the degassing opening, should also preferably be located in a region of the buffer space which is also liquid-free immediately after the periodic pumping back of the separating liquid from the separating container and the possible absorption of liquid from the filling chamber. As a result, the degassing opening, in particular the degassing membrane, cannot be blocked by the liquid.

The at least one further degassing opening is preferably arranged on or in a cover for closing the filling opening and / or in a section of the outer wall delimiting the filling space. Since the buffer space and the filling space are arranged above the storage space, gas occurring in the cavity collects in the buffer space and / or the filling space. A further degassing opening on or in a cover for closing the filling opening and / or in a section of the outer wall delimiting the filling space is therefore expedient. The further degassing opening in the lid is preferably a degassing membrane, since no pressure relief valve is required here, since technically no static pressure can occur at the highest point of the container. The gas can thus escape from the cavity particularly easily, in particular in all operating states of the electrolyser, through the at least one degassing opening and / or further degassing opening in the region of the buffer space and / or the filling space. The further degassing opening designed as a degassing membrane can be realized by a gas-permeable, preferably ring-shaped, cover seal of the cover, in which gas can escape, for example, via a thread of the cover.

The at least one degassing opening can be spaced from the outer wall by a degassing line, for example a hose or a pipe, and can be connected in a fluid-conducting manner to the cavity. The degassing opening can be arranged in particular above the container through the degassing line. This prevents liquid from reaching the degassing opening when the container is being used and preventing gas permeability or escaping in an uncontrolled manner. The degassing line is advantageously designed such that, for example, liquid that has entered the degassing line during transport runs into the cavity during operation of the electrolyzer, for example gravitationally.

On an outside of the at least one degassing opening facing away from the cavity and / or a further degassing opening, a foreign body protection device can be arranged to protect the degassing opening from foreign bodies, for example dust or insects. The foreign body protection device prevents foreign bodies from clogging the degassing opening or impairing their function. The foreign body protection device can comprise, for example, a grid and / or a fleece that is sufficiently fine-meshed to keep the foreign bodies out.

The at least one degassing opening and / or further degassing opening can be closed in a liquid-tight manner by a gas-permeable degassing membrane. This ensures that - in particular if the container is not in its intended orientation, for example during transport - no liquid escapes through the degassing opening in an uncontrolled manner. The liquid tightness of the degassing membrane should be selected so that no liquid can leak out even when the electrolyzer is upside down. The liquid passage pressure of the degassing membrane is defined by its pore size and should be at least as large as the pressure, preferably greater than the pressure that can be exerted on the degassing membrane by the maximum liquid column occurring in the container and, if applicable, by the electrolyser connected to it.

In the case of a PEM electrolyser, for example, the proton exchange membrane should not dry out even during storage and transportation, so that a certain amount of liquid generally remains in the container even during storage and transportation. In order to avoid an uncontrolled escape of the liquid during storage or transport, it is therefore advantageous if the at least one degassing opening and / or further degassing opening of the container is closed in a liquid-tight manner. So that a closure of the degassing opening or degassing openings does not first have to be removed or replaced in order to operate the electrolyzer, it is particularly advantageous if the degassing openings are each sealed liquid-tight by a gas-permeable degassing membrane.

The degassing membrane is advantageously curved and / or inclined relative to a degassing opening plane of the degassing opening. Due to an arched and / or inclined arrangement, liquid which condenses on the degassing membrane and could reduce the gas permeability can run off or drip off the degassing membrane.

The container can comprise at least one pressure relief valve, preferably an umbrella valve, for gas-tight sealing of the at least one degassing opening and / or a further degassing opening. A pressure relief valve on the at least one degassing opening and / or further degassing opening prevents gas from being displaced through the degassing opening and / or further degassing opening from the buffer space into the surroundings of the container when the container is being filled by the liquid which is filled into the cavity. As a result, the entire buffer space would no longer be available free of liquid, so that the remaining buffer space could possibly not be able to hold the entire separation volume.

An opening pressure of the pressure relief valve is preferably greater than a base pressure, which corresponds to a density of the liquid multiplied by the height of the filling space and the gravitational acceleration. This ensures that the pressure relief valve does not already open due to the pressure generated by the liquid column in the filling chamber, but rather only through an additional pressure, for example through gas and / or liquid introduced into the cavity by the electrolyser.

For reliable operation, it has proven to be particularly advantageous to select the opening pressure by 20 mbar to 40 mbar above the base pressure. For water as a liquid and a filling chamber height of 5 cm, for example, there is a base pressure of 5 mbar.

In particularly advantageous configurations, the at least one degassing opening and / or further degassing opening comprises a degassing membrane and a pressure relief valve connected in series with respect to gas transport through the degassing opening, the degassing membrane preferably being arranged on the cavity side of the pressure relief valve. This prevents liquid from accumulating from the cavity between the pressure relief valve and the degassing membrane, which could hinder gas transport through the degassing opening. In a particularly advantageous embodiment, the combination of degassing membrane and pressure relief valve also includes a foreign body protection device.

The at least one return opening can comprise a guide element for guiding a gas and liquid entering the cavity through the return opening, which is in particular designed as an anode return opening. The guide element can comprise, for example, a tube or a hose. The guide element can in particular direct the fluid into a specific region of the cavity. The guide element can, for example, allow gas, for example oxygen, entering through the return opening to escape in the region of the filling space; this has the advantage that when the tank is filled from the outside and the electrolyser is operated at the same time, the gas can escape through the open filler opening so that no water overflows.

The guide element can comprise a silencer for the silenced introduction of the gas and the liquid. The muffler can be designed, for example, by means of a surface structure and / or surface chemistry such that when a liquid containing a gas, for example water with oxygen, enters, only small gas bubbles form and no large gas bubbles which could produce a bubbling noise.

The silencer in the container allows the electrolyzer to be operated with the container in a particularly quiet manner, so that the electrolyzer is particularly suitable for home use and / or therapeutic use.

The jacket wall can, for example, form a jacket surface of a cylinder or prism, a base surface of the cylinder or prism enclosing the outer fill opening. In this form, the circumferential surface can completely enclose the filling space on the circumference and can be easily produced, in particular in the shape of a cylinder.

In particular, the base area can correspond to the outer filling opening. In this case, the jacket wall forms a continuation of the contour of the outer filling opening into the interior of the container, which is particularly easy to implement in terms of production technology.

The container can comprise at least one support device arranged in the cavity, which statically connects two opposite sections of the outer wall to one another. The mechanical stability of the container is improved by the support device, which for example comprises at least one support column and / or at least one support wall. The support device preferably comprises a number of openings for transporting the liquid through the support device. The openings ensure that the support device does not significantly hinder gas transport and / or liquid transport within the cavity.

The jacket wall can be statically connected by the at least one support device to a region of the outer wall opposite the outer filling opening. In particular, the jacket wall can merge in one piece into the support device, so that the container is particularly easy to manufacture.

The container preferably consists at least in sections, in particular completely, of a plastic, preferably of an oxygen-resistant and particularly preferably also ozone-resistant plastic, particularly preferably of a fluorinated plastic. A plastic, in particular oxygen-resistant material, ensures that the container is media-compatible, so that no substances emerging from the container contaminate the liquid. The better the media compatibility and the less substances are released into the liquid, the longer the possible operating time of the electrolyzer.

The container can include other elements such as a level sensor as dry-running protection and / or a conductivity sensor for warning when filling with an incorrect liquid (e.g. tap water) or at long time intervals during operation without changing the water.

An electrolyzer according to the invention for the electrolysis of water can in particular be designed as a proton exchange membrane electrolyzer and preferably comprises a container according to the invention as the water tank of the electrolyzer. The features of the electrolyser described below can be transferred with the described or independent advantages that are obvious to a person skilled in the art to an electrolyzer with a container not designed according to the invention as a water tank.

Advantageously, the at least one flow opening of the container, which preferably opens into the storage space of the container, is fluidly connected to an anode space of an electrolysis cell of the electrolyser via a flow line. Advantageously, the at least one return opening of the container is fluidly connected to a separating container of the electrolyser via a return line, the separating container being fluidly connected to a cathode chamber of the electrolytic cell via a cathode line and a pump valve between the separating container and the container is integrated in the return line or on the separating container . An anode return line connects the anode space of the electrolytic cell in a fluid-conducting manner to the at least one return line between the pump valve and the return opening of the container or via an anode return opening of the container to the cavity of the container. The fluid-conducting connection of the anode space to the return line is particularly advantageous, since this means that no anode return line with its own connection to the container via an anode return opening is necessary.

Through the compounds mentioned in the previous paragraph, water for electrolysis from the Containers flow into the anode compartment of the electrolytic cell and the gas generated in the anode compartment can get back into the container together with water via the anode return line, and separating water, collected in the separating container, from the cathode compartment of the electrolytic cell can periodically in via the integrated pump valve in the return line flow back the container.

For example, with two separate return lines and return openings in the tank, anode return line with anode return opening and pump return line with pump return opening, the respective liquid and gas flow is improved because fewer connection points and therefore fewer connection angles and possible narrow points in the liquid and gas flow impede them.

• Eine Pumprücklauföffnung, die bevorzugt in den Speicher- oder Pufferraum des Behälters mündet, ist über eine Pumprücklaufleitung fluidleitend (vorzugsweise mit einem integrierten Pumpventil) mit dem Abscheidebehälter des Elektrolyseurs verbunden. Eine Anodenrücklauföffnung, die bevorzugt in den Speicher- oder Pufferraum des Behälters mündet,
• ist über eine Anodenrücklaufleitung mit dem Anodenraum der Elektrolysezelle des Elektrolyseurs fluidleitend verbunden.

The container advantageously and preferably comprises two return openings:

• A pump return opening, which preferably opens into the storage or buffer space of the container, is connected in a fluid-conducting manner (preferably with an integrated pump valve) to the separating container of the electrolyzer via a pump return line. An anode return opening, which preferably opens into the storage or buffer space of the container,
• is fluidly connected to the anode compartment of the electrolytic cell of the electrolyzer via an anode return line.

Due to the connections mentioned in the previous paragraph, water for electrolysis can flow through the feed line from the container into the anode compartment of the electrolysis cell and from there through the anode return line back into the container. The water collected in the separation container from the cathode compartment of the electrolytic cell can be pumped back periodically into the container through the pump return line.

The two return lines can both be brought together before entering the container, so that the container then only needs one return opening. The at least one return opening preferably opens into the storage or buffer space of the container.

The pump valve separates the anode side and cathode side of the electrolytic cell from each other outside of this and the connections connected there, so that there is no danger that oxygen from the anode space and hydrogen from the cathode space flow together. A mixture of oxygen and hydrogen could lead to an explosive mixture of oxygen and hydrogen, also known as oxyhydrogen, which could endanger the operational safety of the electrolyzer. Opening the pump valve and closing the hydrogen outlet valve during operation of the electrolysis cell serves to pump back the collected water from the separating tank into the tank by means of the hydrogen gas generated on the cathode side. The duration of this pump-back process should be selected so that only water is pumped and no hydrogen gas gets into the tank via the pump return line.

Pumping with the internally produced gas eliminates the need for an electric pump, making the pumping process very quiet. The separating container can comprise at least one hydrogen outlet valve or a hydrogen outlet valve connected there to conduct fluid or gas and / or at least one fill level sensor. In the separator tank, the hydrogen can be efficiently separated from the water and hydrogen gas mixture from the electrolytic cell and can be used via the hydrogen outlet valve from the separator tank for use, for example, for hydrogen enrichment of drinking water or for inhalation purposes.

The return line can comprise at least one pump valve to shut off the return line between the separating container and the return opening. The return flow of the separating water into the container can be controlled by the pump valve, and when the pump valve is closed, the pump valve separates the cathode side from the anode side of the electrolysis cell. In particular, the pump valve can prevent water from the container or from the anode compartment from flowing counter to the intended flow direction to the cathode compartment, hydrogen gas flowing into the container and mixing there with oxygen, which could cause the electrolyser to malfunction. Furthermore, the controlled pump valve in connection with the likewise controlled hydrogen outlet valve can ensure that only water and no hydrogen gas is pumped into the container during the pump-back process.

The electrolyzer and its fluid return mechanisms, in particular the pumping of the water collected on the cathode side in the separating tank back into the tank, determine the returned fluid volume of this water. This volume of fluid is required for the design of the buffer volume.

The electrolyzer can comprise at least one control device communicatively connected to the fill level sensor and the two valves, hydrogen outlet valve and pump valve, the control device being designed to: To control the hydrogen outlet valve and the pump valve as a function of a fill level of the separating tank measured by the fill level sensor. The control device can, in particular automatically, ensure that the fill level of the separating container is in a range which is advantageous for efficient and safe operation of the electrolyzer, so that in particular efficient hydrogen separation takes place without overflowing the separating container.

Furthermore, the control device can preferably also monitor the internal gas pressure on the cathode side via a pressure sensor, regulate the switching on / off of the electrolysis cell, communicate with an optional touch display and / or display and input elements and be controlled from the outside by the user and via an optional acoustic signal Signalers / loudspeakers give the user advisory tones. The control device can be integrated in the electrolyzer or can be comprised by a computer device external to the electrolyzer.

Preferably, the at least one control device is designed to close the hydrogen outlet valve and to open the pump valve when a maximum fill level, signaled by a fill level sensor, of the separator tank and to open the pump valve until a predetermined separating volume of the separating water from the separator tank has entered the cavity, this Separation volume is less than or equal to the buffer volume of the buffer space of the container. This device ensures that neither the container nor the separating container overflow or that there is an overpressure. In addition, the correct duration of the pumping process prevents hydrogen gas from entering the container.

The at least one hydrogen outlet valve and / or the at least one pump valve is preferably designed as a shape memory metal valve. A shape memory metal valve is switched by heating or cooling a shape memory metal above a transition temperature and therefore works very quietly, in particular in comparison to conventional electromagnetic valves.

The electrolyzer is advantageously designed to circulate the water from the container through the anode side of the electrolytic cell and back into the container through the gas generated by the electrolysis itself. If the lines, connections and internal construction of the electrolytic cell are designed correctly, the resulting gas causes the water to circulate on the anode side, in particular without further pumps, due to its rise in the water.

Shape memory metal valves and / or the absence of further pumps make the electrolyser particularly quiet to operate, which is particularly advantageous when the electrolyser is used at home, for example in a living room or bedroom.

The electrolyzer preferably comprises at least one fan for cooling the electrolyzer. By cooling the electrolyzer, in particular the container and the water pipes, the release of substances from soluble components in contact with the water is slowed down, so that the electrolyzer can be operated longer without problems. The fan also prevents hydrogen from accumulating in a housing of the electrolyzer in the event of a gas leak, which could result in an explosive gas mixture.

The container, all gas or liquid-conducting lines of the electrolyser, line connector, the electrolysis cell, the valves and / or a separating container with level sensor of the electrolyser preferably consists at least in sections, in particular completely, of a hydrogen-resistant and / or oxygen-resistant and in particular also ozone-resistant material made of a fluorinated plastic. This ensures that the components mentioned do not corrode during operation of the electrolyzer and / or contaminate the system and / or lead to a poorer life expectancy of the electrolyzer. Not every component comes into contact with all media contained in the electrolyzer, in particular water, oxygen, ozone, H ₃ O ⁺ or hydrogen, so different materials can be selected for different components depending on the contact medium. Resistance to ozone is important because, due to the application, energy-efficient electrolysis is not absolutely necessary and so the final voltage of the electrolytic cell can be increased so that a longer operating life is achieved and higher voltages could result in small amounts of ozone being generated.

The outer wall of the container preferably comprises an emptying opening for, in particular gravitationally driven, emptying of the container. The emptying opening is advantageously arranged on the storage space, in particular on an underside of the container. The liquid can be removed in a simple manner through the emptying opening, in particular without having to turn the container or the electrolyzer, for example in order to exchange it for fresh liquid, for example if there is a salinity or a concentration of impurities in the liquid for the operation of the electrolyzer is too high.

In the electrolyzer, the emptying opening of the container can be connected in a fluid-conducting manner to an environment of the electrolyzer via an emptying line, which can preferably be closed by a, for example manually operated, emptying valve. The emptying valve is preferably designed to be oil-free and grease-free in order to prevent contamination of the liquid in the container.

Alternatively, the emptying line can also be connected in a fluid-conducting manner at a point in the electrolyser which is lower than the container, preferably with the flow line or the electrolysis cell through a separate connection opening.

All lines of the electrolyser are advantageously connected to the containers, valves and electrolysis cell in such a way that the connections are oil-free and grease-free. This prevents contamination of a liquid in the electrolyzer, for example by a lubricant in a connecting device between the opening and a line. In the case of connections, apart from an inside of an outer wall of a liquid container and an inside of a line connected to the liquid container, no further surfaces are in fluid-conducting contact with the respective interior of the liquid container.

For example, a line, in particular in the form of a semi-flexible hose, can be pressed sealingly against an opening by a combination of a ferrule and a threaded fitting. On the one hand, this ferrul and fitting combination is oil-free and grease-free, on the other hand, it is a very cost-effective connection technology and also saves space. The hose preferably consists of a fluoroplastic.

Furthermore, all materials used in the electrolyzer that are liquid and / or gas-carrying and / or have contact with liquid and / or gas are preferably oil-free and fat-free. This includes in particular all parts of the valve that come into contact with the medium.

The electrolyser can also contain at least one UV light source, preferably for UVC light, preferably a UVC LED light source, for germ reduction, in particular for disinfection. The UV light source can advantageously irradiate the hydrogen gas in the line in the hydrogen flow direction shortly before a hydrogen outlet of the electrolyzer, through a line transparent to UV light and a UV light source outside the line or a UV light source integrated into the line. As a further possibility, the liquid containers and their liquid can also be treated with UV light. In the case of the liquid containers, as with the line, a UV light source can be implemented from the outside of the liquid container with UV-permeable container material, or inside with a UV light source integrated into the liquid container for UV treatment. This is a useful product addition, especially for devices used in the medical field.

1. a) Überwachen eines Füllstands des Abscheidebehälters des Elektrolyseurs, bevorzugt durch ein Messen des Füllstands mit einem Füllstandssensor, und
2. b) Rückführen eines Abscheidevolumens Abscheidewasser aus dem Abscheidebehälter in den Behälter des Elektrolyseurs, sobald der Füllstand einen Maximalfüllstand erreicht, wobei das Abscheidevolumen kleiner oder gleich einem Puffervolumen des Pufferraums des Behälters ist.

A method for the electrolysis of water with an electrolyzer according to the invention comprises at least the following steps:

1. a) monitoring a fill level of the separating tank of the electrolyzer, preferably by measuring the fill level with a fill level sensor, and
2. b) returning a separating volume of separating water from the separating container into the container of the electrolyzer as soon as the fill level reaches a maximum fill level, the separating volume being less than or equal to a buffer volume of the buffer space of the container.

The method ensures safe and efficient operation of the electrolyser without the risk of the separating container or the container overflowing. The method is preferably carried out automatically by a control device of the electrolyzer.

1. a) Schließen des Wasserstoffauslassventils des Elektrolyseurs, sobald der Füllstand den Maximalfüllstand erreicht, und
2. b) Öffnen des Wasserstoffauslassventils des Elektrolyseurs, sobald der Füllstand einen Minimalfüllstand erreicht, wobei das Erreichen des Minimalfüllstands insbesondere durch ein

Messen des Füllstands mit einem Füllstandssensor und/oder durch den Ablauf einer vorbestimmten Zeitdauer seit dem Schließen des Wasserstoffauslassventils bestimmt wird.The return preferably comprises at least the following steps:

1. a) closing the hydrogen outlet valve of the electrolyzer as soon as the fill level reaches the maximum fill level, and
2. b) opening the hydrogen outlet valve of the electrolyzer as soon as the fill level reaches a minimum fill level, the reaching of the minimum fill level in particular by a

Measuring the level with a level sensor and / or determined by the lapse of a predetermined period of time since the closing of the hydrogen outlet valve.

By closing the hydrogen outlet valve, a hydrogen pressure builds up in the separating tank, which can drive the separating water out of the separating tank into the tank, in particular without an additional pump. As a result, the method according to the invention is particularly energy-efficient and low-noise. When the hydrogen outlet valve is opened, the hydrogen pressure drops again, so that no further separating water is forced out of the separating tank.

1. a) Öffnen des Pumpventils, insbesondere nach dem Schließen des Wasserstoffauslassventils, bevorzugt durch einen sich in dem Abscheidebehälter erhöhenden Wasserstoffdruck, und
2. b) Schließen des Pumpventils, insbesondere nach dem Öffnen des Wasserstoffauslassventils, bevorzugt durch einen sich in dem Abscheidebehälter verringernden Wasserstoffdruck.

If the electrolyzer comprises a pump valve, the return preferably comprises the following steps:

1. a) opening of the pump valve, in particular after closing the hydrogen outlet valve, preferably by a hydrogen pressure increasing in the separating container, and
2. b) Closing of the pump valve, in particular after opening the hydrogen outlet valve, preferably due to a hydrogen pressure decreasing in the separating container.

With the help of the pump valve, a return flow of the separating water into the tank can also be controlled. A particularly simple and efficient method results in particular when the pump valve, which is designed, for example, as a pressure relief valve, is controlled by the changing hydrogen pressure.

All of the features disclosed in the application documents are claimed as essential to the invention, provided that they are new to the prior art, individually or in combination.

Brief description of the drawings

Further advantages, aims and properties of the invention are explained with the aid of the following description and attached drawings, in which objects according to the invention are shown by way of example. Features which in the figures at least essentially correspond in terms of their function can be identified with the same reference numerals, these features not having to be numbered and explained in all the figures.

• [1] eine schematische Darstellung einer erfindungsgemäßen Ausgestaltung des Elektrolyseurs;
• [2] eine schematische Darstellung einer erfindungsgemäßen Ausgestaltung des Behälters;
• [3] eine schematische Darstellung einer weiteren erfindungsgemäßen Ausgestaltung des Behälters;
• [4] eine schematische Darstellung einer weiteren erfindungsgemäßen Ausgestaltung des Behälters;
• [5] eine schematische Darstellung einer weiteren erfindungsgemäßen Ausgestaltung des Behälters;
• [6] eine schematische Darstellung einer erfindungsgemäßen Ausgestaltung des Führungselements;
• [7] eine schematische Darstellung erfindungsgemäßer Ausgestaltungen der äußeren Einfüllöffnung;
• [8] eine schematische Darstellung erfindungsgemäßer Ausgestaltungen der Entgasungsöffnung;
• [9] eine schematische Darstellung einer weiteren erfindungsgemäßen Ausgestaltung der Entgasungsöffnung;
• [10] eine schematische Darstellung einer weiteren erfindungsgemäßen Ausgestaltung des Behälters mit einem Führungselement;
• [11] eine weitere schematische Darstellung der in 3 dargestellten Ausgestaltung des Behälters und
• [12] eine vorteilhafte Ausgestaltung einer Verbindung einer Leitung mit einer Behälter-, Elektrolysezellen- oder Ventilverbindungsöffnung.

Show it:

• [ 1 ] a schematic representation of an embodiment of the electrolyzer according to the invention;
• [ 2nd ] a schematic representation of an embodiment of the container according to the invention;
• [ 3rd ] a schematic representation of a further embodiment of the container according to the invention;
• [ 4th ] a schematic representation of a further embodiment of the container according to the invention;
• [ 5 ] a schematic representation of a further embodiment of the container according to the invention;
• [ 6 a schematic representation of an embodiment of the guide element according to the invention;
• [ 7 a schematic representation of embodiments of the outer filler opening according to the invention;
• [ 8th a schematic representation of embodiments of the degassing opening according to the invention;
• [ 9 ] a schematic representation of a further embodiment of the degassing opening according to the invention;
• [ 10th ] a schematic representation of a further embodiment of the container according to the invention with a guide element;
• [ 11 ] another schematic representation of the in 3rd illustrated design of the container and
• [ 12 ] an advantageous embodiment of a connection of a line with a container, electrolysis cell or valve connection opening.

Fig. 1

[ 1 ] shows a schematic representation of an embodiment of the electrolyzer according to the invention 200 , for example a proton exchange membrane electrolyzer. The electrolyzer 200 comprises a container, in particular designed according to the invention 100 as a water tank, with the flow opening 102 of the container 100 via a flow line 202 fluid-conducting with an anode compartment 212 an electrolytic cell 210 of the electrolyzer 200 is connected, and the return port 103 of the container 100 as a pump return opening 103 via a pump return line 203 fluid-conducting with a separating tank 220 of the electrolyzer 200 is connected, the separating tank 220 via a cathode lead 208 fluid-conducting with a cathode compartment 213 the electrolytic cell 210 connected is.

Another return opening of the container 100 is as an anode return opening 104 via an anode return line 204 fluid-conducting with the anode compartment 212 the electrolytic cell 210 connected by a proton exchange membrane 214 from the cathode compartment 213 is separated.

In an alternative embodiment of the anode return line (shown in dashed lines), this can the anode space 212 not with a separate anode return opening 104 of the container 100 but with the return line 203 between the return opening 103 of the container 100 and pump valve 224 Connect fluidly.

For the sake of clarity, further details of the container are 100 in 1 not provided with reference numerals and also not explained here. The container 100 can be configured, for example, as shown in one of the following figures.

The separator tank 220 includes a level sensor 221 and at least one hydrogen outlet valve connected to it 222 . The pump return line 203 includes a pump valve 224 to shut off the pump return line 203 between the separator tank 220 and the pump return opening 103 .

The container 100 can, especially in a bottom of the container 100 , an emptying opening 190 have, via a drain line 290 , for example, by a, in particular manually operated, drain valve 291 can be closed, in particular for gravity-driven emptying of the container 100 with an environment of the electrolyzer 200 is fluidly connected.

Fig. 2

[ 2nd ] shows a schematic representation of an embodiment of the container according to the invention 100 . The container 100 includes one of a gas-tight outer wall 101 , for example made of a plastic, enclosed cavity 110 for taking up a liquid, for example ultrapure water. The container 100 includes an outer fill opening 160 for filling the liquid from an environment of the container 100 in the cavity 110 (in 11 hatched).

The at least one flow opening and the at least one return opening of the container are not shown 100 .

The container 100 comprises at least one filling space 130 , the filler 130 on its top with the outer filler opening 160 is connected in a liquid-conducting manner and on its underside opposite the upper side via an inner filler opening 165 with the storage space 125 is connected in a liquid-conducting manner and via a perpendicular to an opening plane OE of the inner filling opening 165 aligned height of the filling area 130 from an opening area normal to the inner fill opening 165 circumferential wall 170 is completely enclosed on the circumference. In the embodiment shown is a section 171 the jacket wall 170 from the outside wall 101 educated.

The coat wall 170 is gas-tight above the opening level OE, and the opening level OE divides the cavity 110 outside the loading area 130 into a buffer space 140 with a buffer volume above the opening level OE and a storage space 125 below the opening level OE for receiving the liquid. The entire inner cavity 110 is filled by the three sub-rooms 130 , Buffer space 140 and storage space 125 educated.

The container shown 100 further includes a lid 161 to close the outer filling opening 160 and a gas permeable vent 150 for releasing a gas, in particular oxygen, from the cavity to the surroundings of the container 100 , the vent opening 150 in a the buffer space 140 delimiting section of the outer wall 101 , in particular on an upper side of the container 100 , is arranged.

Fig. 3

[ 3rd ] shows a schematic representation of a further embodiment of the container according to the invention 100 . In contrast to that in 2nd The embodiment shown is the jacket wall 170 here for example as a jacket of a cylinder or prism, the base of the outer fill opening 160 and the inner filler opening 165 correspond, designed. In addition, in 3rd also the height H of the filling area 130 drawn.

Fig. 4

[ 4th ] shows a schematic representation of a further embodiment of the container according to the invention 100 . In the 4th embodiment shown differs from that in 3rd illustrated in that the vent 150 through a degassing line 154 , for example a pipe, from the outer wall 101 spaced and with the cavity 110 is fluidly connected. The vent opening 150 is located above the outer filler opening, for example 160 .

Fig. 5

[ 5 ] shows a schematic representation of a further embodiment of the container according to the invention 100 . In the 5 embodiment shown differs from that in 2nd illustrated that the jacket wall 170 through a support device 171 static with one of the outer filling opening 160 opposite area of the outer wall 101 , in particular with a bottom of the container 100 , connected is. The support device 171 is, for example, as an openwork extension of the jacket wall 170 designed.

Fig. 6

[ 6 ] shows a schematic representation of an embodiment of the guide element according to the invention 180 for guiding one, in particular through the anode return opening 104 , in the cavity 110 entering liquid-gas mixture, the guide element 180 prefers comprises a silencer for the silenced introduction of the liquid-gas mixture.

Fig. 7

[ 7 ] shows a schematic representation of embodiments of the outer filler opening according to the invention 161 with or without a further degassing opening arranged thereon 149 . In 7A no further degassing opening is provided. Alternatively, the lid 160 as in 7B another vent 149 with a degassing membrane 151 include. In a further embodiment of the lid 160 as in 7C the further degassing opening can be shown 149 be designed like one of the in 8th Refinements of the degassing opening shown 150 .

Fig. 8

[ 8th ] shows a schematic representation of embodiments of the degassing opening according to the invention 150 . In all of the configurations shown, the degassing opening comprises 150 a pressure relief valve 153 , for example a screen valve, for closing the at least one degassing opening 150 up to a predetermined positive pressure in the cavity 110 .

In the in the 8A , 8B and 8C The embodiment shown is the degassing opening 150 from a gas permeable degassing membrane 151 sealed liquid-tight. The degassing membrane 151 and the pressure relief valve 153 are related to gas transport through the vent 150 arranged in series, the degassing membrane 151 ( 8A , 8C ) or the pressure relief valve 153 ( 8B) the cavity 110 is arranged facing.

In addition, the cavity 110 side of the degassing opening facing away 150 a foreign body protection device 152 , for example a grid and / or fleece, to protect the degassing opening from foreign bodies, for example dust or insects. The foreign body protection device 152 is particularly in the 8C shown embodiment with degassing membrane 151 inside and pressure relief valve 153 important on the outside, as any foreign objects that may fall in would otherwise function as a relief valve 153 could affect.

8D shows a particularly simple design of the degassing opening 150 that are neither a degassing membrane 151 another foreign body protection device 152 includes.

In the 8E Shown embodiment of the degassing opening 150 differs from that in 8D illustrated embodiment in that on the cavity 110 side of the degassing opening facing away 150 additionally a foreign body protection device 152 is arranged.

Fig. 9

[ 9 ] shows a schematic representation of a further embodiment of the degassing opening according to the invention 150 . The design corresponds to that in 8C shown embodiment, with the additional design of the pressure relief valve 153 as an umbrella valve and a curvature of the degassing membrane 151 , for example convex to the cavity 110 , is visible.

Fig. 10

[ 10th ] shows a schematic representation of a further embodiment of the container according to the invention 100 with a guide element 180 . In this embodiment, the guide element 180 arranged so that it passes through the anode return opening 104 in the container 100 entering gas, for example oxygen, into the filling space 130 of the container 100 directs. From there, the gas can flow through the outer filler opening, for example 160 (if this, for example when filling the container 100 , not through a lid 161 is closed) and / or a degassing opening (not shown) in an environment of the container 100 escape.

Fig. 11

[ 11 ] shows a further schematic representation of the container 100 in the in 3rd shown configuration, being in contrast to 3rd the entire cavity 110 of the container 100 is marked by hatching. The others in 11 features provided with reference numerals correspond to those in 3rd features provided with the same reference numerals.

Fig. 12

[ 12 ] shows an advantageous embodiment of a connection of a line, for example an emptying line 290 , the electrolyser (not shown) with an opening of the container, for example an emptying opening 190 the container, or other openings or connections from the separating container, the electrolytic cell or the valves of the electrolyzer. The emptying opening is only an example of the container 190 containing section of the outer wall 101 of the container. The emptying line, designed for example as a semi-flexible hose 190 is in the example shown by a fitting 293 and a ferrul 294 sealing against an edge of the opening pressed. The fitting 293 presses through the tightened screw connection 292 the ferrul 294 against the outer wall 101 and the drain line 190 and so seals the connection. The opening configuration in the respective container, valve or the electrolysis cell is preferably adapted to the geometric conditions, for example a round container or flat plate.

Reference symbol list

100

container

101

Outer wall

102

Flow opening

103

Return opening / pump return opening

104

Anode return opening

110

cavity

125

Storage space

130

Filling space

140

Buffer space

149

further vent opening

150

Degassing opening

151

Degassing membrane

152

Foreign body protection device

153

Pressure relief valve

154

Degassing line

160

outer filler opening

161

cover

165

inner filling opening

170

Jacket wall

171

Support device

180

Silencer

190

Drain opening

200

Electrolyser

202

Supply line

203

Return line / pump return line

204

Anode return line

208

Cathode lead

210

Electrolytic cell

212

Anode compartment

213

Cathode compartment

214

Proton exchange membrane

220

Separator tank

221

Level sensor

222

Hydrogen outlet valve

224

Pump valve

290

Drain line

291

Drain valve

292

Screw connection

293

fitting

294

Ferrul

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 19653034 A1 [0005]

Claims (15)

Container (100) for a liquid for use as a water tank of an electrolyzer (200) with a) a cavity (110) enclosed by an at least partially gas-tight outer wall (101) for receiving the liquid and b) at least one outer filling opening (160) for filling the liquid from an environment of the container (100) into the cavity (110) and c) at least one flow opening (102) for dispensing liquid from the cavity (110) to an electrolysis cell (210) of the electrolyzer (200) and d) at least a return opening (103) for admitting into the cavity (110) and e) at least one filling chamber (130) of other components of the electrolyzer (200) during operation with a period of discharge of periodically discharged liquid and continuously discharged gas and discharged liquid, wherein the Filling space (130) e1) on its upper side is connected to the outer filler opening (160) in a liquid-conducting manner and e2) on its upper side opposite underlying underside is connected to the cavity (110) in a liquid-conducting manner via an inner filler opening (165) and e3) over a height (H) of the filler chamber which is oriented perpendicular to an opening plane (OE) of the inner filler opening (165) from a normal to the inner surface of an inner surface Filling opening (165) circumferential jacket wall (170) is completely enclosed on the circumference, characterized in that f) the jacket wall (170) above the opening level (OE) is gas-tight, and g) the opening level (OE) the cavity (110) outside the filling space (130) divides into a buffer space (140) with a buffer volume above the opening level (OE) and a storage space (125) below the opening level (OE) for receiving the liquid, the buffer space (140) for completely receiving a dispensed within a delivery period Volume of the liquid is designed, and h) the container (100) in a section of the outer wall (101) delimiting the buffer space (140) ndest comprises an at least gas-permeable degassing opening (150) with a pressure relief valve (153) for releasing a gas from the cavity (110) to the surroundings of the container (100), the pressure relief valve (153) for gas-tight sealing of the at least one degassing opening (150) is designed, and an opening pressure of the pressure relief valve (153) is greater than a base pressure, which corresponds to a density of the liquid multiplied by the height (H) of the filling chamber (130) and the gravitational acceleration. Container (100) after Claim 1 , characterized in that the at least one degassing opening (150) with the pressure relief valve (153) is liquid-tightly closed by a gas-permeable degassing membrane (151), the degassing membrane (151) a) being in series with the gas transport through the degassing opening (150) Pressure relief valve (153), preferably on the cavity side of the pressure relief valve (153), is arranged and b) is preferably arranged inclined with respect to a degassing opening plane and / or is configured to be curved. Container (100) after Claim 1 or 2nd , characterized in that on the side of the at least one degassing opening (150) facing away from the cavity (110) with the pressure relief valve (153) or the at least one degassing opening (150) with the pressure relief valve (153) and a degassing membrane (151) with respect to gas transport a foreign body protection device (152) is arranged in series through the degassing opening (153). Container (100) according to one of the Claims 1 to 3rd , characterized by at least one further gas-permeable degassing opening (149) for releasing a gas from the cavity (110) to the surroundings of the container (100), the at least one further degassing opening (149) a) in a cover (161) for closing the outer filling opening (160) is arranged and / or b) is arranged in a section of the outer wall (101) delimiting the filling space (130). Container (100) according to one of the Claims 1 to 4th , characterized in that the at least one degassing opening (150) is spaced from the outer wall (101) by a degassing line (154) and is connected in a fluid-conducting manner to the cavity (110). Container (100) according to one of the Claims 1 to 5 , characterized in that the pressure relief valve (153) is a screen valve. Container (100) according to one of the Claims 1 to 6 , characterized in that the at least one return opening (103) comprises a guide element (180) for guiding a liquid-gas mixture entering the cavity (110) through the return opening (104), the guide element (180) preferably being a muffler includes silenced introduction of the liquid-gas mixture. Container (100) according to one of the Claims 1 to 7 , characterized in that the lateral wall (170) a) forms a lateral surface of a cylinder or prism, a base surface of the cylinder or Prism encloses the outer filler opening (160), preferably corresponds to the outer filler opening (160) and / or b) is spaced from a region of the outer wall (101) opposite the outer filler opening (160). Container (100) according to one of the Claims 1 to 8th , characterized by at least one support device (171) arranged in the cavity (110), which statically connects two opposite sections of the outer wall (101) to one another, the support device (171) preferably a) having a number of openings for transporting the liquid through the Support device (171) extends through and / or b) statically connects the casing wall (170) to a region of the outer wall (101) opposite the outer filling opening (160). Container (100) according to one of the Claims 1 to 9 , characterized in that the container (100) consists at least in sections of a plastic, preferably of a plastic resistant to oxygen, preferably also to ozone, particularly preferably of a fluorinated plastic. Electrolyser (200), in particular proton exchange membrane electrolyser, for the electrolysis of water, characterized by a container (100) according to one of the Claims 1 to 10th as a water tank of the electrolyzer (200), wherein a) the at least one flow opening (102) of the container (100), which preferably opens into the storage space (125) of the container (100), via a flow line (202) in a fluid-conducting manner with an anode space ( 212) an electrolysis cell (210) of the electrolyzer (200) is connected, and b) the at least one return opening (103) of the container (100) is fluidly connected to a separating tank (220) of the electrolyzer (200) via a return line (203) , wherein the separating container (220) is fluidly connected to a cathode chamber (213) of the electrolytic cell (210) via a cathode line (208), and c) a pump valve (224) between the return opening (103) and the separating container (220) Return line (203) or on the separating tank (220) is integrated, and d) an anode return line (204) the anode space (212) of the electrolytic cell (210) with the return line (203) between the return opening (103) and pump valve (224 ) t or via an anode return opening (104) of the container (100) to the cavity (110) of the container (100), optionally with a muffler (180) installed there, so that together with the supply opening (102) and the supply line ( 202) a water circulation from the container (100) via the anode compartment (212) and back to the container (100) is possible, and e) a hydrogen outlet valve (222) is connected to the separation container (220) above the highest possible water level in the separation container, and f) at least one level sensor (221) is integrated in the separating tank (220), so that the at least one level sensor (221) detects at least a maximum water level of the separating tank (220), and g) a drain valve (291), preferably a manual one Actuating valve, in the bottom of the container (110) or to underlying components connected to the anode chamber (212) in a fluid-conducting manner in order to be able to empty the container. Electrolyser (200) after Claim 11 , characterized in that a) the at least one hydrogen outlet valve (222) and / or the at least one pump valve (224) is designed as a shape memory metal valve, and / or b) the electrolyzer (200) does not include any electric water pumps, with b1) the liquid circulation for the water supply and cooling of the anode side of the electrolysis cell (210) without a pump is made possible by a corresponding design of the lines, connections and the internal structure of the electrolysis cell, in that the gas rising through the electrolysis also takes water with it and thus acts as a water pump, and / or b2 ) the pumping back process of separating water collected in the separating container (220) from the cathode side of the electrolytic cell (210) by means of the gas produced on the cathode side via the return line (203) and the corresponding switching of the hydrogen outlet valve (222) and the pump valve (224), which displaces the water collected in the separating tank (220), he follows. Electrolyser (200) after Claim 11 or 12 , characterized in that all line connections within the electrolyzer (200), in particular by ferrule (294), fittings (293) and matching semi-flexible fluoroplastic hoses, in particular with the respective containers, valve connections and the electrolysis cell, are designed to be oil-free and grease-free, with preference all materials used in the electrolyzer (200) which carry liquid and / or gas and / or are in contact with it, are oil-free and grease-free. Electrolyzer (200) according to one of the Claims 11 to 13 , characterized in that a) the electrolyzer (200) comprises at least one fan for cooling the electrolyzer (200). Electrolyzer (200) according to one of the Claims 11 to 14 , characterized in that the Electrolyser (200) comprises at least one UV light source in order to treat hydrogen gas and / or liquid contained in the electrolyser (200) by UV light, in order to reduce germs in the hydrogen gas and / or the liquid, in particular ultrapure water, in particular disinfection, the at least one UV light source or a plurality of UV light sources preferably being or being integrated in the electrolyzer (200) as follows: a) at least one UV light source, preferably for UVC light, preferably a UVC LED -Light source, is located in the hydrogen transport direction just before a hydrogen outlet of the electrolyzer (200), so that the hydrogen gas in the line, through a line transparent to UV light and a UV light source outside the line or an integrated UV light source in the line is treated, and / or b) in the case of a liquid container, preferably the container (100) on the anode side, the at least one UV light source be placed outside the liquid container with UV-permeable container material or inside the liquid container with a UV light source integrated into the liquid container.

Images