Heating device for water and water-conducting domestic appliance having such a heating device

Abstract

A heating device for water has a water channel body with at least one water channel as an elongate, continuous depression in the water channel body, the water channel being sealed off from the outside and being accessible through the channel inlet and channel outlet. Heating with a heating conductor is provided on the water channel body. The water channel body is in the form of a plate and, like the cover and the entire heating device, is curved, with the water channel being formed by deep drawing. A cover which covers the water channel and seals same along its length is placed onto the water channel body. The cover contains the heating with the heating conductor, the heating being extensively distributed over the cover by a meandering course of the heating conductor.

Description

[0001] Heating device for water and water-bearing household appliance with such a heating device

[0002] SCOPE OF APPLICATION AND STATE OF THE ART

[0003] The invention relates to a heating device for water, in particular for a water-bearing household appliance with a water channel. Furthermore, the invention relates to a water-bearing household appliance with such a heating device.

[0004] Such heating devices and household appliances equipped with them are known from the prior art, see for example EP 1 975 517 A1. This allows for a practical design and provides a good way to generate hot water.

[0005] With this heating device, it is not only important to generate as much hot water as quickly and / or as possible, for which rapid and / or strong heating by a heating element is advantageous, but also to ensure operational safety and to avoid overheating of the heating device or heating element.

[0006] TASK AND SOLUTION

[0007] The invention is based on the objective of creating a heating device and a water-bearing household appliance as mentioned above, with which problems of the prior art can be solved and in particular it is possible to generate hot water as quickly and safely as possible.

[0008] This problem is solved by a heating device with the features of claim 1 and by a water-bearing household appliance with the features of claim 15. Advantageous and preferred embodiments of the invention are the subject of further claims and are explained in more detail below. Some features are described only for the heating device or only for the household appliance. However, they should be able to apply independently and separately to both such a heating device and to a household appliance equipped with it. The wording of the claims is incorporated into the description by express reference.

[0009] The heating device, which is intended to heat water and possibly even generate steam, has a water channel body containing at least one water channel. Advantageously, this water channel is open within the water channel body but will be sealed in the finished heating device. The water channel is formed by an elongated, continuous recess in the water channel body. It is sealed to the outside, particularly in the fully assembled or operational state of the heating device. It is accessible via an inlet and an outlet, which advantageously open into the water channel at their respective ends. Furthermore, the heating device incorporates a heating element on the water channel body.This heating system is designed as an electric resistance heater and includes at least one heating conductor, preferably either a very long heating conductor or several individual heating conductors connected in parallel and / or series. One or more continuous or meandering heating conductor tracks are also conceivable for the heating device.

[0010] A cover is placed on the water channel body, covering at least one water channel or all of the water channels. Advantageously, the cover seals the one or all of the water channels along their length, so that they are only accessible at the aforementioned channel ends via the channel inlet and outlet. The heating device therefore has at least two parts: the water channel body and the attached cover, these two advantageously forming a single unit.

[0011] According to the invention, the water channel body is designed as a plate or in a plate-like form. It can be relatively flat or thin, yet curved, i.e., partially rounded. Preferably, it has a relatively small thickness compared to its surface area or greatest longitudinal dimension; in particular, the thickness is between 1% and 10% or between 2% and 7%, i.e., independent of the curvature height. Its total height, including the water channel body, can be approximately 5% to 40%, preferably 15% to 35%. The cover is preferably also curved in shape, in particular in the same way as the water channel body, in order to match the shape of the water channel body. This curvature of the entire heating device is advantageous.

[0012] The at least one water channel, or all water channels, are formed in this plate as an elongated and continuous recess. By curving the heating element, the projected area can be kept smaller for the same heating surface and / or water channel length. This is advantageous when the available area is limited, for example, because there is no more space in the appliance. This requires slightly more height, which may, however, be available. The aforementioned cover incorporates the heating element with the at least one heating conductor; advantageously, heating is provided exclusively on the cover. The heating element on the cover is formed or distributed across its entire surface. The at least one heating conductor can either be formed across its entire surface or have a continuous, continuous design. It can then completely cover a specific area, advantageously a rectangular area.Alternatively, the at least one heating conductor can only partially cover a larger area or heating zone, for example in a grid-like manner or by parallel heating conductors running next to or parallel to each other, but with a distance between them.

[0013] Thus, the invention makes it possible for the heating device to consist essentially of two parts: a water channel body and a cover. The two essential functions of the heating device are divided in such a way that the water channel body primarily handles the water channeling function. The cover performs the other function of the heating device, namely heating, or rather, it contains the heating elements. Simultaneously, the cover also seals the water channels, preventing any water from escaping the heating device except at the channel inlet and outlet, and minimizing or preventing any water from passing directly between individual water channels, particularly adjacent ones. Therefore, the water channel body can be manufactured relatively simply, namely as an open structure. The water channels are closed by the cover.

[0014] In this embodiment of the invention, the heating element is advantageously provided and arranged on the surface or outer side of the cover facing away from the water channel path. The at least one heating conductor or all heating conductors of the heating element can cover at least 50% of the cover's surface, preferably at least 70% to 95% of its surface or outer side.

[0015] In a first embodiment of the invention, the heating can be provided by at least one narrow and elongated heating conductor. Preferably, the heating conductor can run along the at least one water channel and directly opposite or above it. This allows for the most direct and rapid heating of the water flowing therein.

[0016] In a second embodiment of the invention, the heating can be provided by at least one planar and advantageously rectangular heating conductor. This heating conductor can either be formed by a closed surface or, alternatively, it can have a grid-like configuration. This is known from the prior art. In a further development of the invention, the heating can be provided by several heating circuits, which are advantageously controllable separately and independently of one another. In this way, heating of different heights and locations can be achieved. Several heating circuits can run in the same area of ​​the cover. In particular, narrow, elongated heating conductors can be configured to interlock, for example, in a comb-like or meandering pattern.

[0017] In principle, the heating conductors can be of various designs, for example, tubular heating elements, heating wires, or the like. Preferably, they are designed as at least one thick-film heating conductor, preferably as several narrow thick-film heating conductors arranged in parallel paths and / or in a meandering pattern.

[0018] Preferably, the at least one water channel in the water channel body can cover more than 50% or 60% of the surface area of ​​the water channel body, particularly preferably up to 95%. This can be achieved by a distributed arrangement of the water channel. This allows for the most compact design possible of the heating device, or, given a specific size, the water channel can be as long as possible for optimal water heating.

[0019] In one embodiment of the invention, the at least one water channel has a constant width and / or a constant flow cross-section; preferably, this applies to all water channels in the water channel body. This ensures the most uniform flow possible and thus also the most uniform generation of warm or hot water. Preferably, a single water channel with a meandering shape is provided.

[0020] The advantage of a water channel body being constructed in one piece and as a single unit is particularly beneficial, especially when made from a single material. This allows for a simple and robust design.

[0021] In a further development, the at least one water channel within the water channel body can terminate before an outer edge of the water channel body, i.e., within the surface or outer edges of the water channel body. The channel inlet and outlet can be provided at the respective ends of the water channel, preferably through the cover, or alternatively through the water channel body itself. Pipe stubs can be provided as channel inlets and outlets leading to the channel ends. They can be attached to and fastened to the cover or project from it, advantageously at substantially right angles. They are advantageously made of the same material as the cover, in particular metal or stainless steel, and can be welded on. A channel inlet and an outlet are preferably arranged in corner regions of a rectangular or polygonal cover to maximize the available surface area for the water channel. Preferably, they can be arranged in adjacent corner regions.

[0022] The at least one water channel in the water channel body can be formed by stamping it into a previously flat, planar metal sheet; this is known. It can be stamped in a single step or in several steps, possibly also by deep drawing. Except for a peripheral area where the water channel body can have the thickness of the original sheet, the thickness of the entire water channel body should only vary by a maximum of 10% or 20%, i.e., in the area where the water channel runs. Thus, it is always approximately or exactly the same size.

[0023] In a further development of the invention, the water channel body can be bent into the curved shape, or it can be produced in this curved shape by embossing or deep drawing. The at least one water channel can be formed simultaneously, before or after bending a flat sheet into the curved shape of the sheet; advantageously, all of this is carried out in a single step.

[0024] Preferably, the lid and the water channel body are made of the same material, in particular metal, whereby the lid and / or the water channel body may be made of stainless steel. However, other or different materials may also be used if the application permits or requires it.

[0025] Alternatively, at least the water channel body can be made of plastic, in particular injection-molded plastic, preferably fiber-reinforced.

[0026] The lid and the water channel body can have the same surface area, dimensions, and shape; preferably, the curvature is also the same or exactly the same. This allows them to fit together as well as possible and be tightly connected.

[0027] Advantageously, the cover is permanently and tightly connected to the water channel body, particularly by welding in the case of metal or by bonding. This permanent connection can be continuous along an outer edge of the cover and / or the water channel body, ensuring the heating device is watertight. Preferably, they can also be connected to each other at specific points along their surface area, especially between two adjacent water channels. In this case, the cover seals the entire water channel as effectively as possible. Alternatively, the cover can be tightly connected to the water channel body but also be detachable, particularly by being screwed on. This allows for repairs.

[0028] The cover can be thin, preferably made of flat material with a thickness between 0.5 mm and 2 mm. It can also be bent into the desired shape. Alternatively, it can be cut from a solid tube as a partial circumference. This is advantageous if the heating elements are thick-film heating elements, as multiple units can then be produced and subsequently separated.

[0029] The heating device can preferably be uniformly curved, particularly around an axis running along the longitudinal axis. In this case, the length along this axis is greater than the width perpendicular to it. The heating device can comprise between 20% and 35% of the circumference of a surrounding tube; the cover can, in fact, be cut out of such a tube.

[0030] An electrical connection device for the heating device or heating system is advantageously provided on the outside of the lid, in particular as a plug connector attached to it for quick and easy electrical connection.

[0031] In addition to heating, a discrete temperature sensor can be provided on the heating device, advantageously located on the outside of the lid. It is electrically connected via the connection device. An additional or alternative method for area-wide temperature measurement is described in DE 10 2015 218 120 A1, as is known per se.

[0032] The water-bearing household appliance according to the invention has a heating device as described above, preferably on the rear side of the appliance's housing. This can be particularly advantageous if the heating device extends vertically. The heating device can advantageously be designed and arranged such that the drain is higher than the inlet. It is particularly advantageous if the water channel does not descend at any point in the direction from the inlet to the drain.

[0033] These and other features are evident not only from the claims but also from the description and the drawings, whereby the individual features, either alone or in combination, may be implemented in one embodiment of the invention and in other fields, and may represent advantageous and individually protectable embodiments for which protection is claimed here. The division of the application into individual sections and subheadings does not limit the general validity of the statements made therein.

[0034] BRIEF DESCRIPTION OF THE DRAWINGS

[0035] An embodiment of the invention is schematically illustrated in the drawings and is explained in more detail below. The drawings show:

[0036] Fig. 1 shows a highly simplified rear view of a household appliance according to the invention, wherein a heating device according to the invention is provided on the rear of the appliance.

[0037] Fig. 2 shows an oblique view of a finished heating device,

[0038] Fig. 3 shows a view of an end face of the curved heating device from Fig. 2.

[0039] Fig. 4 shows a top view of the heating device or of the top of a cover with a heating conductor area and heating conductors.

[0040] Fig. 5 is an exploded view of the heating device from Fig. 2 in a different perspective view, showing the meandering course of the one long water channel in the lower water channel body,

[0041] Fig. 6 is an exploded view with a perspective similar to Fig. 2, showing the channel ends, which terminate at the channel inlet and outlet, and

[0042] Fig. 7 shows a top view of the upper side of the water channel body, from which the course of the entire water channel with its two channel ends can be seen.

[0043] DETAILED DESCRIPTION OF THE EXECUTION EXAMPLES

[0044] Figure 1 shows a household appliance 11 according to the invention, comprising a housing 12. The heating device 15 according to the invention is attached to the rear 13 of the housing, with a water inlet 17 and a water outlet 18. Cold water enters the heating device 15 via the water inlet 17, either by the pressure of a water pipe in a building or by means of a pump. Warm, hot, or very hot water, possibly even steam, exits the water outlet 18. This heated or hot water can then be used in the household appliance 11. This is not of significant importance to the invention.

[0045] Figure 2 shows the heating device 15 according to the invention in an oblique view. As shown in the exploded views of Figures 5 and 6, the heating device 15 consists of a lower water channel body 20 onto which a cover 30 is placed and permanently attached. In particular, the two parts are welded together.

[0046] As can be seen from Fig. 2 and the following figures, the water channel body 20 has a bottom surface 21 that lies, so to speak, within the curvature, which is particularly evident in Fig. 3. On this bottom surface 21, the indentations 22 protrude, forming the water channel 27 on a top surface 24 of the water channel body 20, as shown in Figs. 5 and 6. According to the top view of the top surface 24 in Fig. 7, a single continuous water channel 27 is provided, which runs in a meandering pattern with straight sections connected by curves. In this way, a total of twenty straight sections of the water channel 27 are formed, with a channel end 28a on the left and a channel end 28b on the right in Fig. 7.

[0047] Perimeter regions 25a, 25b, 25c, and 25d extend around the entire water channel 27 on the upper surface 24 of the water channel body 20. They serve to connect or weld to perimeter regions 43 on an underside 42 of the cover 30, as shown, for example, in Fig. 6. Advantageously, perimeter regions 25a to 25d and perimeter regions 43 all lie on a precise circular cylinder, allowing for a very tight seal. These perimeter regions 25a to 25d have a width of at least 2 mm to 5 mm for a secure connection or weld. Fig. 7 also shows that the channel ends 28a and 28b extend to perimeter region 25d, i.e., they are designed with maximum length. In the middle of perimeter region 25d, there is a recess 26 where the water channel is further away from perimeter region 25d. This will be explained in more detail below.

[0048] The view of the end face in Fig. 3 shows that the heating device 15 is relatively thin, meaning its thickness is relatively small in relation to its width and length. Furthermore, it is very thin in the edge regions outside the water channel 27; this corresponds to the wall thickness of the water channel body 20 in the edge region 25 and the wall thickness of the cover 30. This cover 30 advantageously has the same material thickness throughout, which can be either 1 mm or 2 mm. The water channel body 20 and the cover 30 are advantageously made of stainless steel. The water channel body 20 is advantageously formed by a stainless steel plate, which is embossed in one or two stages to create the water channel 27 and is also bent into the curved or convex shape shown in Fig. 3. The actual material wall thickness can therefore vary between the somewhat thicker edge region 25 and the somewhat thinner wall thickness at the water channel 27.The cover 30 has a top surface 31, which is essentially covered by a heating conductor area 33. This heating conductor area 33 is essentially covered or formed by the heating conductors 34. These heating conductors 34 can, as indicated, run in a meandering pattern similar to the water channel 27. It is even possible for the heating conductor to run directly above the water channel 27, so that it can heat the water flowing along it as efficiently and directly as possible. Alternative configurations for the heating conductors 34 include several heating conductors running parallel to each other, which are also electrically connected in parallel. The heating conductors 34 could also be located in two different heating circuits, which are either spatially separated or interwoven. In this way, locally different heating of the water can be achieved, as well as heating with different power levels and thus different temperatures.The heating conductors 34 can also be in grid form; alternatively, they can be formed over a solid surface. Reference is made to possible configurations of the heating conductors as described in WO 2021 / 170232 A1 or WO 2021 / 170331 A1.

[0049] The heating conductors 34 form linear heating conductors, advantageously manufactured using thick-film technology. They can be connected directly or via connecting tracks in a known manner to a plug connector 36, which is shown here in a very simplified form. It can be attached to the top surface 31 of the cover 30, for example with metal feet, which are welded in place, in particular, at contact points.

[0050] Figures 2 and 4 show that a temperature sensor 38 is provided in an edge region and a corner region. This sensor can also be electrically connected to the plug connector 36. It can be designed as an SMD component or in another form. It can thus be arranged, at least in this corner region, where a channel end 28b is advantageously located for the outlet of the heated water, in order to detect its temperature. Other surface-based methods for temperature measurement are known, for example, from the aforementioned DE 10 2015 218 120 A1.

[0051] Access to the water channel 27 in the assembled state of the water channel body 20 and cover 30 is provided at the channel ends 28a and 28b by means of the pipe stubs 40a and 40b. These are advantageously made of metal or stainless steel and are welded to the cover 30 above the channel ends, corresponding to a bore in the cover 30. The pipe stubs 40a and 40b could also be designed differently, for example, angled or with specific connections such as screw connections, etc. Several weld points 45 can be seen in the top view of Fig. 4. At these weld points, the water channel body 20 and the cover 30 are welded together in addition to the edge area, in order to ensure the tightest possible contact between the top surface 24 of the water channel body 20 and the bottom surface 42 of the cover 30, even within the area of ​​the heating device 15. This results in the most complete possible seal of the water channel 27.

Claims

Patent claims 1. Heating device for water comprising: a water channel body with at least one water channel formed by an elongated continuous depression in the water channel body, wherein the at least one water channel is sealed to the outside and is accessible by a channel inlet and a channel outlet, a heating element on the water channel body, wherein the heating element comprises at least one heating conductor, characterized in that the water channel body is designed as a curved plate, the at least one water channel is formed in the plate as an elongated continuous depression, a cover is placed on the water channel body, which covers the at least one water channel and preferably seals it along its length, the cover has the heating element with the at least one heating conductor,wherein the heating is distributed over the entire surface of the lid by means of a fully enclosed design of the at least one heating conductor or by a course of the at least one heating conductor that partially covers a larger area.

2. Heating device according to claim 1, characterized in that the heating is provided on the outside of the lid facing away from the water channel body path, wherein preferably the at least one heating conductor or all heating conductors of the heating cover at least 50% of the surface of the lid.

3. Heating device according to claim 1 or 2, characterized in that the heating is formed by at least one narrow and elongated heating conductor, wherein the heating conductor is preferably arranged along the at least one water channel and exactly opposite or running above it.

4. Heating device according to one of the preceding claims, characterized in that the heating is formed by several separate and independently controllable heating circuits, wherein preferably the heating circuits run in the same surface area of ​​the cover.

5. Heating device according to one of the preceding claims, characterized in that the heating is formed by at least one thick-film heating conductor, preferred- wisely through several narrow thick-film heating conductors arranged in parallel tracks and / or with meandering arrangement.

6. Heating device according to one of the preceding claims, characterized in that the at least one water channel in the water channel body terminates in front of an outer edge of the water channel body, wherein the channel inlet and the channel outlet are provided through the cover, wherein preferably pipe stubs are provided as channel inlet and as channel outlet which are attached to and project from the cover, wherein in particular the channel inlet and the channel outlet are arranged in corner regions of a rectangular or polygonal cover, preferably in adjacent corner regions.

7. Heating device according to one of the preceding claims, characterized in that the at least one water channel in the water channel body is formed by embossing into a previously flat planar circuit board, wherein preferably the thickness of the entire water channel body varies only by a maximum of 10% or 20%.

8. Heating device according to one of the preceding claims, characterized in that the water channel body has been bent into the curved shape or has been produced by deep drawing in the curved shape, wherein in particular the at least one water channel has been formed simultaneously, before or after bending a flat circuit board into the curved shape of the board.

9. Heating device according to one of the preceding claims, characterized in that the lid and the water channel body are made of the same material.

10. Heating device according to one of the preceding claims, characterized in that the cover has the same surface area and the same extent as the water channel body, preferably also the same curvature.

11. Heating device according to one of the preceding claims, characterized in that the cover is permanently and tightly connected to the water channel body, in particular welded or glued, wherein the permanent connection is provided continuously along an outer edge of the cover and / or the water channel body and preferably also at points in the surface area, in particular between two adjacent water channels.

12. Heating device according to one of claims 1 to 10, characterized in that the cover is detachably and tightly connected to the water channel body, in particular by screwing.

13. Heating device according to one of the preceding claims, characterized in that it is uniformly curved, in particular about an axis extending along the longitudinal axis, wherein preferably the heating device forms between 20% and 35% of the circumference of a circumferential tube.

14. Heating device according to one of the preceding claims, characterized in that an electrical connection device for the heating is provided on the outside of the lid, in particular as a plug connection attached thereto, wherein preferably a discrete temperature sensor is arranged on the outside of the lid and is electrically connected by means of the connection device.

15. Water-bearing household appliance with a heating device according to one of the preceding claims, wherein the heating device is preferably arranged on a rear side of a housing of the household appliance, in particular with longitudinal extension in a vertical direction.

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