DE102019000378A1 - Hot water device and method for operating a hot water device - Google Patents

Abstract

The invention relates to a hot water device (1), in particular a hot water tank, with a tank (10) and a corrosion protection device (20) for protecting the tank from corrosion, the corrosion protection device (20) having a sacrificial anode (24) and an external current anode (22) , each reversibly mountable within the memory (10) and insulated from the memory (10), the corrosion protection device (20) having a potential determination unit (42) which is set up to establish a potential between the external current anode (22) and the memory (10), wherein the wear detection unit (30) is set up to determine wear of the sacrificial anode (24) based on the potential determined by the potential determination unit (42). The invention also relates to a method (200) for controlling corrosion protection of a hot water device, in particular a hot water tank.

Description

The present invention relates to a hot water device and a method for operating a hot water device. A hot water device is in particular a hot water tank, but is not limited to this. The present invention is used in particular in all areas in which corrosion protection is required.

It is known, particularly in the area of hot water storage tanks, to provide different types of corrosion protection systems. The often enamelled storage containers that are used in such devices have flaws that develop into corrosion spots without appropriate passivation. Sacrificial anodes and external current anodes are particularly noteworthy as examples of corrosion protection systems. The advantage of sacrificial anodes is that the corrosion protection is maintained even without a power supply, and the power consumption of the hot water device is reduced. Thereby, sacrificial anodes, which often have magnesium, are consumed by the use and have to be replaced in due course, the determination of the time when the sacrificial anode is used up being complicated.

From the US 8,649,671 an external current anode coated with magnesium is known. The magnesium initially present ensures passivation of the defects, long-term corrosion protection is ensured by the externally fed electrical current.

From the DE 101 126 60 as well as the utility model DE 20 2004 017 83 hot water tanks with a sacrificial and an external current anode are known. The devices described have switching devices in order to switch from the external current anode to the sacrificial anode in the event of a power failure, thereby ensuring continuous corrosion protection.

From the DE 10 2004 004 064 a device for monitoring a sacrificial anode is known. The state of the sacrificial anode is determined via the protective current.

From the WO 2007/010 335 a hot water device with an external current and a magnesium anode is known, which are used in combination.

Against the background of the prior art, it was an object to provide an improved hot water device which ensures reliable corrosion protection with reduced power consumption.

According to a first aspect, the object is achieved by a hot water device, in particular a hot water tank, with a tank and a corrosion protection device for protecting the tank against corrosion. The corrosion protection device has a sacrificial anode and an external current anode, each of which is reversibly mountable within the memory and insulated from the memory, the corrosion protection device having a potential determination unit which is set up to determine a potential between the external current anode and the memory, the wear detection unit is set up to determine wear of the sacrificial anode based on the potential determined by the potential determination unit.

Insulated mounting of the external current anode or the sacrificial anode in the memory means that there is no direct electrical contact between the respective anode and the metallic container housing. Insulation is placed between the container and the respective anode.

The invention is based on the finding that the electrical potential between the external current anode and the memory indicates a consumption state of the sacrificial anode. The electrical potential and thus the protection potential of the memory depends on the state of consumption of the sacrificial anode. This embodiment accordingly enables the anode condition to be actually recorded.

In one embodiment, the hot water device has an electrical control which is set up to selectively supply the external current anode with current, the potential determination unit preferably being designed as part of the electrical control.

In one embodiment, the sacrificial anode is electrically connected to the memory, in particular de-energized, to the memory via the electronics of the electrical control by means of a switchable contact.

In one embodiment, the hot water device also has a wear detection unit which is set up to detect wear of the sacrificial anode and to apply electrical potential to the external current anode when wear of the sacrificial anode is detected.

Because the corrosion protection device according to the invention has a wear detection unit, the external current anode is only subjected to electrical potential when wear of the sacrificial anode is detected, as a result of which power consumption is eliminated whenever the sacrificial anode is not worn. A particularly strong reduction in power consumption can be achieved, in particular, when the wear detection occurs without current. Compared to the prior art, in which, for example, the sacrificial anode is provided as a safety solution in the event that the external current anode fails, for example in the event of a power failure, the external current anode is provided here as an emergency solution for the failure, that is to say the consumption, of the sacrificial anode.

In one embodiment, the wear detection unit has a pressure switch, which is set up to trigger when the sacrificial anode is worn.

The pressure switch has the particular advantage that a contact which, for example, applies electrical potential to the external current anode, is only closed when a mechanical action, namely by pressure, acts on the wear detection unit. All designs of pressure switches known to the person skilled in the art are suitable for the present application.

In one embodiment, the pressure switch is arranged such that when the sacrificial anode wears, an internal pressure of the reservoir is applied to the pressure switch, which is suitable for triggering the pressure switch.

In one embodiment, the sacrificial anode has a cavity on the inside, which is insulated from the container volume in an unused state, the pressure switch being in fluid communication with the cavity, such that the pressure switch is triggered when the external current anode breaks into the cavity .

As soon as the sacrificial anode is used up sufficiently, the water from the interior of the storage device enters the cavity inside the sacrificial anode, the internal pressure of the container is applied to the pressure switch. This triggers the pressure switch. Accordingly, the pressure switch is designed in particular in such a way that the internal pressure which is present in the storage device of the hot water device is sufficient for triggering.

In one embodiment, the triggering of the pressure switch closes the circuit of the external current anode.

By closing the circuit of the external current anode directly by triggering the pressure switch, a particularly simple supply of the external current anode with the protective current is possible. In particular, a mechanical coupling can directly lead to the mechanical movement or triggering of the pressure switch closing the circuit.

In one embodiment, the hot water device has an electrical control, the triggering of the pressure switch providing a signal to the electrical control and the electrical control being set up to supply the external current anode with current when the signal of the pressure switch is obtained.

By triggering the pressure switch to provide a signal that is indicative of the sacrificial anode being used up to an electrical control system, an adapted reaction to the consumption of the sacrificial anode is possible. For example, as an alternative or in addition to directly supplying the external current anode with current, the electrical control system can output a signal by means of an operating unit. The signal can then give the user an indication that the sacrificial anode has been used up and needs to be replaced. Likewise, as an alternative or in addition, a delay can be built into the application of current to the external current anode. It is usually the case that the pressure switch is triggered before the sacrificial anode is completely used up. After the pressure switch has been triggered, the electrical control can therefore wait for some time, for example, until the external current anode is supplied with current. During this transition period, a consumption signal can already be issued to a user.

In one embodiment, the sacrificial anode is mounted insulated within the memory and is electrically connected to the memory via the electronics of the electrical control by means of a switchable contact, in particular is connected to the memory without current.

The switchable contact for connecting the sacrificial anode to the memory can in particular be designed as a field effect transistor or as a relay. The preferred currentless connection between the sacrificial anode and the memory means that during the operating period during which the sacrificial anode is not used up, no electrical current is required to ensure the corrosion protection.

In one embodiment, the electrical control is set up to separate the electrical connection between the sacrificial anode and the memory when the signal from the pressure switch is obtained.

The separation of the sacrificial anode and the memory when the pressure switch signal is obtained is advantageous for the operation of the external current anode, since the sacrificial anode, when it is connected to the container is connected, represents an external cathode for the external current anode and accordingly increases electrical power consumption while ensuring corrosion protection by means of an external current anode. In this embodiment, the current consumption is reduced while ensuring the corrosion protection by means of an external current anode.

In one embodiment, the hot water device also has a display unit, the electrical control being set up to output a consumption state of the sacrificial anode to the display unit based on the signal from the pressure switch.

For example, up to a moment when the pressure switch triggers, the display can indicate that the sacrificial anode has not been used up. With triggering it can then be displayed that the sacrificial anode has been used up. It is also preferably indicated that a certain time has passed since the pressure switch was triggered. A display can, for example, switch to yellow when triggered and ultimately switch to red after a certain time, red being understood as a sign that the sacrificial anode really needs to be replaced. Of course, these are only examples of how the state of consumption of the sacrificial anode can be shown on the display unit; other configurations are also conceivable.

In one embodiment, the hot water device also has a heating flange which is set up to heat up the interior of the store, the sacrificial anode being introduced into the heating flange and being conductively connectable to the container or being mountable directly in the store.

In one embodiment, the corrosion protection device has a DC voltage source for supplying the external current anode with DC current, the DC voltage source being a constant or a regulated DC voltage source.

In this embodiment, the electrical potential between the external current anode and the memory can particularly advantageously indicate a state of consumption of the sacrificial anode. This embodiment is based on the knowledge that the electrical potential and thus the protective potential of the memory depend on a state of consumption of the sacrificial anode. This embodiment accordingly enables the anode condition to be actually recorded.

In one embodiment, the sacrificial anode is electrically connected to the memory by means of a switchable contact, the potential determination unit being set up to determine the potential between the external current anode and the memory cyclically, in particular at regular intervals.

Because the potential is determined cyclically, it is possible to make a statement about the consumption state of the sacrificial anode at cyclical intervals.

In one embodiment, the potential determination unit is set up to open the contact between the sacrificial anode and the memory for a potential determination between the external current anode and the memory.

By opening the contact between the sacrificial anode and the memory, sources of error for determining the potential between the external current anode and the memory are minimized. In particular, this enables an IR-free measurement. The brief disconnection of the electrical connection between the sacrificial anode and the storage tank is not critical for corrosion protection. After carrying out the potential determination, the electrical contact is preferably closed again, so that the corrosion protection remains ensured.

In one embodiment, the hot water device has an operating unit, in particular with a display device, and / or an interface, in particular a wireless interface such as WLAN, the wear detection unit being set up to send a signal describing the wear of the sacrificial anode to the operating unit and / or the interface to spend.

By means of the display device and / or the interface, the hot water device can communicate the status, in particular of the sacrificial anode. This embodiment, which includes the display device and / or the interface, can be combined with all of the embodiments described above. In particular, the display device and / or the interface can be combined together with the detection by means of a pressure switch and / or with potential measurement.

According to a further aspect, the object is further achieved according to the invention by a method for controlling corrosion protection of a hot water device, in particular a hot water tank. The hot water tank has a tank and a corrosion protection device with sacrificial anode and external current anode. The method has the following steps: determining a potential between the external current anode and the memory; Disconnecting an electrical connection between the sacrificial anode while determining the potential between the external current anode and the memory; and determining wear of the sacrificial anode based on the between External current anode and memory of certain potential, and optionally when it is determined that the wear exceeds a predetermined threshold: communicating the wear to a control unit and / or an interface of the hot water device; and / or applying a DC voltage supply to the external current anode, preferably a DC voltage supply that can be regulated as a function of the specific wear; and / or closing the electrical connection of the sacrificial anode from the memory.

The method according to this aspect allows the same advantages as the hot water device according to the invention described above. In particular, the versions of the hot water device described as preferred can also be applied analogously to the method according to this aspect and can thus advantageously be combined.

• 1 schematisch und exemplarisch ein Warmwassergerät,
• 2 schematisch und exemplarisch eine weitere Ausführung eines Warmwassergerätes,
• 3 schematisch und exemplarisch eine weitere Ausführung eines Warmwassergerätes und
• 4 schematisch und exemplarisch ein Flussdiagramm eines Verfahrens zum Steuern eines Korrosionsschutzes eines Warmwassergerätes

Further advantages and preferred configurations are described below with reference to the attached figures. Here show:

• 1 schematically and exemplarily a hot water device,
• 2nd schematically and exemplarily a further embodiment of a hot water device,
• 3rd schematically and exemplarily a further embodiment of a hot water device and
• 4th schematically and exemplarily a flow diagram of a method for controlling corrosion protection of a hot water device

1 shows schematically and exemplarily a water heater designed as a hot water tank 1 . The water heater 1 includes a memory 10th inside a container volume 12th comprises, in particular water to be heated, preferably process water, is kept ready. About a radiator 14 will the in the memory 10th liquid, especially water, heated. The radiator 14 is via a heating flange 16 in the example in the bottom of the store 10th assembled. Inlets and outlets of the storage 10th are just like electrical connections of the radiator 14 omitted in the drawing for the sake of simplicity. Water heaters 1 , such as the hot water tank shown as an example, are generally known in the art.

The hot water device according to the invention 1 differs from the known hot water devices by the design of the corrosion protection. There is a corrosion protection device for this 20 provided an external current anode 22 and a sacrificial anode 24th includes. The positioning of the sacrificial anode 24th and the external current anode 22 inside the store 10th is arbitrary. The example shown arrangement within the heating flange 16 is an option, but alternatively the respective anodes can of course also be stored directly in the memory 10th to be assembled.

The corrosion protection device 20 has a wear detection unit 30th on, which is set up to wear the sacrificial anode 24th to recognize. Inside the sacrificial anode 24th is a channel for this 26 trained in fluid communication with a pressure switch 32 stands. As an alternative to a pressure switch 32 this element can also be designed as a pressure sensor. Due to self-corrosion and the reactions required for cathodic corrosion protection, the material of the sacrificial anode 24th gradually consumed. When the material degradation has progressed accordingly, water leaks out of the container volume 12th in the channel 26 with which the water pressure at the pressure switch 32 is applied and actuated. For this purpose, the pressure switch can have a sensor unit, for example. By this pressure in the channel 26 Incoming water becomes an electrical contact 33 actuated and the external current anode 22 electrically conductive, for example with a DC voltage source in electronics 40 , connected. The DC voltage source can be a constant or a regulated voltage source.

The external current anode 22 is insulated in the water heater 1 brought in. Even the sacrificial anode 24th is with insulation in this example 28 isolated in the store 10th brought in. An electrical connection 29 secures the end of the circuit between the sacrificial anode 24th and wall of the store 10th . Alternatively, the sacrificial anode 24th also be in direct electrical contact with the container wall.

With the electronics 40 is a control panel 50 connected. On the control panel 50 can be a state of consumption of the sacrificial anode 24th be communicated. Alternatively, it can also be used in electronics 40 an interface, for example a wireless interface such as WLAN, etc., can be provided, so that a consumption state of the sacrificial anode 24th is transmitted to a user via the interface.

2nd shows schematically and exemplarily another version of the hot water device 1 . 2nd differs from 1 in the design of the wear detection unit 30th , especially the pressure switch 32 trained, not the circuit of the external current anode 22 to close directly, but by closing a contact 36 a signal to the electronics 40 to provide. The electrical contact of the pressure switch 32 is then in electronics 40 processed further. This results in advantages in the detection of errors in the corrosion protection device 20 as well as with the Display options, especially via the control panel 50 . The power supply of the external current anode 22 is then in this embodiment depending on the signal of the pressure switch 32 through electronics 40 activated or switched.

Furthermore, in 2nd be seen that the sacrificial anode 24th installed in isolation and via the electronics 40 and a contact 38 electrically with the store 10th connected is. Accordingly, is on the electronics 40 an electrical contact which is the sacrificial anode 24th with the container of the store 10th connects. This contact is preferably closed when de-energized, in particular by means of a relay or a field effect transistor. When the sacrificial anode is consumed 24th , i.e. when the pressure switch is triggered 32 , the sacrificial anode 24th by means of electronics 40 from the store 10th be separated. This is for the operation of the external current anode 22 advantageous because the sacrificial anode 24th when using the store 10th is connected, an external cathode for the external current anode 22 represents.

3rd shows schematically and exemplarily another version of the hot water device 1 . Instead of the pressure switch 32 the wear by the wear detection unit 30th achieved in this example by a potential measurement. In this example, the external current anode 22 and the sacrificial anode 24th each with insulation 28 and separate from the heater flange 16 shown assembled, of course also a combination of one or both of the anodes in the heating flange 16 is conceivable.

The external current anode 22 and the sacrificial anode 24th are about electronics in this example 40 with the store 10th connected. The wear detection unit 30th includes in electronics 40 a potential determination unit 42 , which is set up to detect the protection potential in the container, and a preferably regulated DC voltage source 44 , which is designed to impress the protection potential. The protection potential is in particular called the potential between the external current anode 22 and tank wall of the store 10th Roger that. The protective potential builds up in particular in the vicinity of the container wall in the store, and the potential is preferably used approximately between the external current anode and the container wall.

About the potential determination unit 42 the protection potential in the container is recorded cyclically. The detection is also carried out when the corrosion protection via the sacrificial anode 24th is ensured. A switch is activated during the potential measurement 46 opened so none through the voltage source 44 impressed voltage is present. For an IR-free measurement, the electrical connection between the sacrificial anode is also briefly used 24th and memory 10th by means of a switch 48 Cut.

Based on the detected protection potential, the sacrificial anode can be used in operation 24th on the consumption status of the sacrificial anode 24th be inferred. As in the other versions, the consumption status can be given to the user via the control panel 50 or an interface, for example WLAN, etc., is displayed and / or used for control purposes. In this version it is possible to record the actual anode condition.

In the design of the hot water device 1 according to 3rd corrosion protection can be provided either by the sacrificial anode 24th or through the external current anode 22 can be ensured, preferably only ever one of the two corrosion protection variants is active. Is the corrosion protection via the external current anode 22 ensured, so the electrical connection by means of the switch 48 between the isolated sacrificial anode 24th and memory 10th interrupted. Accordingly, the electrical connection between the DC voltage source 44 and external current anode 22 by means of the switch 46 then interrupted when the corrosion protection via the sacrificial anode 24th is ensured.

The desk 48 is preferably closed in the de-energized state, whereby the corrosion protection can also be ensured in the event of a power failure. Field-effect transistors or relays are suitable for this.

There are several operating options for the corrosion protection device 20 conceivable according to this version. Namely, the sacrificial anode 24th take over the basic corrosion protection, whereby the external current anode 22 then becomes active and takes over the corrosion protection when the sacrificial anode 24th is used up and can no longer guarantee corrosion protection. It is also conceivable that the external current anode 22 ensures basic corrosion protection and the sacrificial anode 24th Corrosion protection is only guaranteed in the de-energized state.

4th shows schematically and exemplarily a flow diagram of a method 200 for controlling corrosion protection of a hot water device. The hot water device can in particular be one of the hot water devices described with reference to the above explanations 1 be.

The procedure 200 has a step 210 disconnecting the electrical connection between the sacrificial anode 24th and memory 10th on and a subsequent step 220 of determining a potential between the external current anode 22 and memory 10th on. Alternatively, the potential determination can of course also be carried out continuously or at regular intervals, in addition to the case in which step 210 the electrical connection has been disconnected.

In one step 230 will wear the sacrificial anode 24th based on the in step 210 certain potential between the external current anode 22 and memory 10th certainly. For example, the potential can be compared with a threshold value. Optionally, it can be determined that the wear exceeds the predetermined threshold.

In one step 232 will the step 230 certain wear on a control panel 50 and / or an interface of the hot water device 1 communicates. Alternatively or additionally, in one step 234 a DC voltage supply to the external current anode 22 applied to the corrosion protection by means of the external current anode 22 ensure. Alternatively or additionally, in one step 236 by closing the switch, for example 48 an electrical connection of the sacrificial anode 24th with the store 10th closed. This provides corrosion protection through the sacrificial anode 24th ensured.

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

• US 8649671 [0003]
• DE 10112660 [0004]
• DE 20200401783 [0004]
• DE 102004004064 [0005]
• WO 2007/010335 [0006]

Claims (10)

Hot water device (1), in particular hot water tank, with a memory (10) and a corrosion protection device (20) for protecting the memory against corrosion, wherein the corrosion protection device (20) has a sacrificial anode (24) and an external current anode (22), each of which can be reversibly installed within the store (10) and insulated from the store (10), wherein the corrosion protection device (20) has a potential determination unit (42) which is set up to determine a potential between the external current anode (22) and the memory (10), the wear detection unit (30) being set up to prevent wear of the sacrificial anode ( 24) based on the potential determined by the potential determination unit (42). Hot water device (1) after Claim 1 The hot water device (1) has an electrical control (40) which is set up to selectively supply the external current anode (22) with current, the potential determination unit (42) preferably being designed as part of the electrical control (40). Hot water device (1) after Claim 2 The sacrificial anode (24) is electrically connected to the memory (10) via the electronics of the electrical control (40) by means of a switchable contact (38), in particular is connected to the memory (10) without current. Hot water device (1) according to one of the Claims 1 to 3rd , wherein the hot water device (1) further comprises a display unit, the electrical control being set up to output a consumption state of the sacrificial anode (24) based on the signal of the pressure switch (32) to the display unit. Hot water device (1) according to one of the preceding claims, wherein the hot water device (1) further comprises a heating flange, which is set up to heat the interior of the memory, wherein the sacrificial anode (24) is introduced into the heating flange and is conductively connectable to the container or can be mounted directly in the memory (10). Hot water device (1) according to one of the preceding claims, wherein the corrosion protection device (20) has a direct voltage source (44) for supplying the external current anode (22) with direct current, the direct voltage source (44) being a constant or a regulated direct voltage source (44). Hot water device (1) according to one of the preceding claims, wherein the sacrificial anode (24) is electrically connected to the memory (10) by means of a switchable contact (38), the potential determination unit (42) being set up to determine the potential between the external current anode (22) and to determine the memory (10) cyclically, in particular at regular intervals. Hot water device (1) according to one of the preceding claims, wherein the potential determination unit (42) is set up to open the contact (38) between the sacrificial anode (24) and the memory (10) for a potential determination between the external current anode (22) and the memory (10) . Hot water device (1) according to one of the preceding claims, wherein the hot water device (1) has a control panel (50), in particular with a display device, and / or an interface, in particular a wireless interface such as WiFi, with the potential determination unit (42) is set up to output a signal describing the wear of the sacrificial anode (24) to the control unit (50) and / or the interface. Method (200) for controlling corrosion protection of a hot water device, in particular a hot water tank, the hot water tank having a memory (10) and a corrosion protection device with sacrificial anode (24) and external current anode (22), the method comprising the following steps: - determining (210) a potential between the external current anode (22) and the memory (10), - Disconnect (220) an electrical connection between sacrificial anode (24) and memory (10) while the potential between the external current anode (22) and memory (10) is determined, and - Determining (230) wear of the sacrificial anode (24) on the basis of the potential determined between the external current anode (22) and the memory (10), and optionally determining that the wear exceeds a predetermined threshold value: - Communicate (232) the wear to a control panel (50) and / or an interface of the hot water device (1), and / or - Applying (234) a DC voltage supply to the external current anode (22), preferably a DC voltage supply that can be regulated depending on the specific wear, and / or - Closing (236) the electrical connection of the sacrificial anode (24) from the memory.

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