EP1405014A1

EP1405014A1 - Electric water heater

Info

Publication number: EP1405014A1
Application number: EP02751078A
Authority: EP
Inventors: Markus Helminger
Original assignee: BSH Bosch und Siemens Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2001-06-26
Filing date: 2002-06-26
Publication date: 2004-04-07
Anticipated expiration: 2022-06-26
Also published as: ES2354255T3; DE50214781D1; EP1600707B1; PL204440B1; EP1405014B1; EP1600707A1; ATE488736T1; PL364487A1; DE10130610A1; RU2003137579A; CN100416173C; WO2003002919A1; CN1520505A

Abstract

The unit consists of two parts (1,2) of plastic. Joined by welding or gluing they form a chamber (3) for water and a self supporting two part tubular heater (4), the section to which this is secured being a two component injection moulding in which are formed access holes (5) for the heater. A cell (7) for the membrane (8) is formed between the container parts. Pushbutton switches (12,13) control the heater halves, selected by a rotary knob (14). A cover (6) clips into position.

Description

Electrically heated water heater

The present invention relates to an electric hot water heater according to the preamble of claim 1.

Such a water heater is known from the German utility model GM 6607855, in which a continuous-flow heater is described with an internally electrically heated channel body, which is covered by two head pieces to form a closed water channel, one head piece having devices for wall suspension. The installation of this instantaneous water heater disadvantageously requires that the entire channel body must be installed first before the hot water heater can be further assembled.

The present invention has for its object to provide a hot water heater of the type mentioned, which is inexpensive and easy to manufacture and has a compact design.

According to the invention, this object is achieved by a hot water heater with the features of patent claim 1. Advantageous further developments and refinements of the present invention are defined in the subclaims. The hot water heater can be, for example, a small storage tank and in particular a water heater.

The assembly of all functional components on a container part simplifies manufacture considerably, since almost all assembly operations are carried out on a single component. In this way, assembly in an assembly line in particular is facilitated, in which a container part is guided through several assembly stations, in each of which functional components are mounted on the container part, it being possible for residual container parts to be assembled in one of these assembly stations in order to completely assemble the container. All functional components are preferably mounted on one container part, but it is also sufficient if at least the essential functional components of the hot water heater are mounted on one of the container parts. The essential functional components are, for example, the heating device, an inflow device, an outflow device, a controller, a flow switch, display elements. elements, controls, temperature sensors or other components that serve the function and in particular the control of the water heater. The assembly container part, to which all or at least the essential functional components of the hot water heater are mounted, can thus remain the central component during the entire manufacturing process, to which all other, usually smaller components are attached.

If a heating device is used in which at least the section projecting into the container is self-supporting, the arrangement of the heating device in the container can be determined. In particular, the heating device can be arranged within the container such that the heated sections of the heating device cannot come into contact with the container wall, so that a heating device with a high power density can be used. This enables high performance in relation to the size of the water heater to be achieved. Furthermore, in such a case, the container can be made from a non-temperature-resistant, inexpensive material such as plastic, since a safe distance from the heater to the wall can be ensured. The heater can be, for example, a tubular heater. The manufacturing costs and the size of the water heater can be reduced in this way.

The container advantageously has fastening devices for mounting the hot water heater, wherein the fastening devices can also be designed exclusively on a container part. In particular, these can be devices for wall mounting the hot water heater, such as holes for the passage of screws or bolts.

A container part can also be designed as a housing section of the hot water heater. In particular, the rear wall of the hot water heater can be formed by a container part, wherein the container can be constructed from two container parts. For this purpose, the container part can have flat extensions which form at least parts of the housing. Advantageously, a container part serving as the rear wall of the hot water heater has the devices for mounting the hot water heater.

In order to form a housing of the hot water heater, the container and in particular a container part alone can furthermore have devices for fastening a device hood, so that a hood can be assembled with very little effort can be. This device can be a snap connection. In particular, the appliance hood can form the front wall of the hot water heater. If a container part is designed as a housing section such as the rear wall and additionally has the devices for fastening a hood, all that is required to complete the housing of the hot water heater after mounting all the functional components on the container is to put the hood on and snap it into place.

The assembly can be further simplified in that at least one container part, on which functional parts are mounted, is designed in two-component plastic injection molding. In this case, seals for the functional components which protrude into the container or are connected to the interior of the container can already be formed at the correct locations during the manufacture of the container part in question, so that no additional work step is required to insert seals. An elastomer can be used as a component for this. In particular, these seals can be provided for a heating device projecting into the container or for a safety pressure valve connected to the container. In this way, it is also possible to form membranes, for example for controlling switching functions, by molding a cavity or at least one depression in a container part and then a membrane extending over this depression from an elastic component.

The container can advantageously have an annular interior. The water to be heated can be passed through the container in such a way that it flows through the container in a single direction. In such a case, the water can be guided along a distance along the heating device which essentially corresponds to the circumference of the annular container interior. Thus, even with a small size of the hot water heater, the water can be guided along the heater over a long distance.

If the interior of the container is annular, a container in the form of a torus results. The ring-shaped interior does not necessarily have to be designed as a closed ring, but can in particular also only be designed as a horseshoe-shaped or U-shaped ring section. The annular or toroidal container can have an inflow device for water, which is arranged in such a way that in the operating state of the hot water heater, the water flows through the container essentially against gravity. This ensures that the water rises from the bottom to the top of the tank and any air bubbles introduced with the water are conveyed upwards against the force of gravity. This has the advantage that no air bubbles are retained in the container.

The container preferably has a drainage device for water, which is arranged such that in the operating state of the hot water heater, air bubbles rising against the force of gravity can be driven out of the container by the water. This has the advantage that air bubbles which move upwards against the force of gravity due to the flow of the water or solely by their own buoyancy force do not accumulate at the upper end of the container and remain there. Remaining air bubbles could collect into an ever larger air bubble and displace the water in the tank until the heating device is exposed. If the heater is exposed, there is a risk that it will overheat and become damaged. In order to avoid this, provision is made to provide the drainage device at least close to or directly at the point at which air bubbles could collect.

In a further variant of a hot water heater, a branch is provided, by means of which the water flowing in via an inflow device can be divided into two partial flows, for flowing through a container in two different directions. Each partial flow occurs at a low initial temperature and in particular only runs through half a length of the heating device. This results in a better heat yield, ie the efficiency is improved because there is a high temperature difference between the entering water and the heating device in both partial flows at the water inlet. With such a high temperature gradient, the heat transfer from the heating device to the water is improved. As an alternative to a single, common heating device, both partial flows can be heated separately. For this purpose, each of the two partial flows can be provided with its own heating device. This has the advantage that the two partial flows can be controlled separately and independently of one another. At a convergence of the two separate partial flows at the end of the heating section, the water flows, which can have different temperatures, can be mixed together again. In the case of an annular or toroidal container, the water flows clockwise in one partial flow and counterclockwise in the other partial flow. The two partial flows are brought together again at the end of the two sections and the heated water leaves the tank via a common drainage device.

Due to the ring or toroidal shape of the container, the functional components can be arranged on a surface of the container part which is surrounded by the annular interior of the container. This has the advantage that the inner area surrounded by the ring-shaped or toroidal container section can be used in a space-saving manner for accommodating functional components. This results in a particularly compact design of the hot water heater.

In the case of a container with an annular interior, for example, a membrane can or a Venturi nozzle can be arranged particularly advantageously such that the annular container interior extends around the membrane can or Venturi nozzle, so that these functional components are arranged in a space that does not contribute to the interior of the container anyway ,

A membrane can or a Venturi nozzle can be designed in a hot water heater according to the invention by designing a recess in each of two different container parts and, for example, arranging the membrane between them, which is held between the two container parts and closes the two recesses, so that the two Depressions form two pressure spaces separated from each other by means of the membrane. Alternatively, the depression can be provided in only one of the two container parts and the other container part can be flat. Such a membrane can can be used in particular in connection with a Venturi nozzle to record the flow rate in a water heater. The flow rate can be taken into account when setting the heating output.

A pressure relief valve can be arranged on that part of the container which is free of the essential functional components. This has the particular advantage that water that escapes after the pressure relief valve has been triggered can be kept away from the functional components. Since the functional components can also include electrical components, it makes sense if they do not come into contact with water. An exemplary embodiment of the invention is described in more detail below with the aid of schematic representations. In it show:

1 shows a sectional view of an embodiment of the hot water heater according to the invention;

Fig. 2 is a plan view of another embodiment of the invention

Hot water heater; 3 shows a perspective view of the embodiment according to FIG. 2.

The hot water heater shown in Fig. 1 is a continuous-flow heater and has a container for heating the water, which consists of two container parts 1, 2, which are made of plastic, for example, and can be welded or glued for connection to one another, for example. In the interior of the container 1, 2, an electric heating device 4 in the form of a tubular heater is arranged, which is held in the upper half of the container 2 and is designed to be self-supporting, so that the exact position of the heating device 4 within the container 1, 2 and the heating device are fixed 4 can not touch the container parts 1, 2. The heating device 4 has two heating circuits which can be acted upon or switched separately with current in order to be able to change the power supplied to the water.

The two container parts 1, 2 enclose an annular interior 3, in which the water to be heated is circulated in one direction, the hot water heater having inflow and outflow devices, not shown. The sections of the heating device 4 which extend through the upper container part 2 are sealed off from the upper container part 2 by means of seals 5, the upper container part 2 being carried out in two-component plastic injection molding and the seals 5 being produced of the upper container part 2 have been formed in the bushings for the heating device 4. To assemble the heating device 4, it only has to be inserted into the upper container part 2 from below. A grounding and holding clamp 15 is fastened to a section of the heating device 4 lying outside the container 1, 2, by means of which the heating device 4 can be connected to earth and can be attached in a heat-conducting manner to the power semiconductors which may be used to control the power supply to the heating device 4.

In the hot water heater shown, the heating power is also partly controlled as a function of the water flow, the water flow being measured by means of a membrane socket 7 which is connected to the interior 3 of the container via a channel 10. The inside of the membrane box 7 has a membrane 8 which divides the interior of the membrane box 7 into an upper and a lower cavity, of which the lower cavity is connected via the channel 10 to the interior 3 of the container 1, 2. The membrane box 7 is arranged in the center of the annular interior 3. The two cavities of the membrane box 7 are formed by depressions in the two container parts 1, 2, which come to lie one above the other when the two container parts 1, 2 are joined and thus form the interior of the membrane box 7. The membrane 8 is arranged between the two container parts 1, 2 before being joined, so that the membrane 8 is held between them after the container parts 1, 2 have been joined and the two depressions of the container parts 1, 2 are covered and sealed.

The membrane 8 is biased downward into the lower cavity by a compression spring 9 arranged in the upper cavity. As soon as water is removed from the hot water heater or as soon as hot water is drawn off, the water begins to flow inside the interior 3 and causes a pressure drop inside the interior 3 at a venturi nozzle (not shown). The Venturi nozzle is connected to the space above the membrane 8, so that the pressure drop at the Venturi nozzle causes the membrane 8 to deflect upward.

A switching cam 11 is fastened to the top of the membrane 8 via a push rod, which cam is shifted vertically in accordance with the pressure difference between the lower and the upper cavity of the membrane box 7. The switching cam 11 has two side buttons that act on microswitches 12, 13. The two buttons of the switching cam 11 are in each case ramps, so that the switching cam 11 widens downward and the buttons run outward when the switching cam 11 moves upward. The two microswitches 12, 13 can switch the two heating circuits separately. A rotary knob 14 can be used to set whether no, one or both heating circuits of the heating device 4 are switched on when water is removed by means of the membrane 8.

All of the functional components described above that serve the function of the hot water heater are fastened to the upper container part 2, so that this forms a central assembly during the assembly of the hot water heater. Manufacturing, in particular in an assembly line, is simplified because the upper container part 2 can be guided through the assembly line from the start, and all subsequent assembly operations can be carried out on this upper container part 2.

The lower container part 1 also forms the rear wall of the hot water heater. For this purpose, the lower container part 1 has a flat extension at the edge which, together with the section of the container part 1 delimiting the container interior 3, essentially forms a surface with which the hot water heater can be mounted, for example, on a wall. For this purpose, the lower container part 1 has holes 18 or breakthrough possibilities which serve to fasten the lower container part 1 or the entire hot water heater. For example, the water heater can be attached with screws that are screwed into the wall through the holes 18.

Furthermore, the lower container part 1 has snap fastenings 17 with which a hood 6 can be fastened. The hood 6 can cover the container 1, 2 together with the functional components and together with the lower container part 1 form a housing of the hot water heater. The hood 6 has a recess for the rotary knob 14, so that the hood 6 can subsequently be attached to the lower container part 1 without the rotary knob 14 having to be removed beforehand. To assemble the hot water heater, it is first attached to the installation site without the hood 6 using the rear wall or the lower container part 1 and the fastening devices or holes 18 provided therefor, and the hood 6 is then snapped onto the lower container part 1.

A pressure relief valve 16 is additionally formed on the upper container part 2 and is set up in such a way that when an internal pressure exceeds a certain limit pressure pressure in the interior 3 of the container 1, 2 opens and excess pressure can escape from the interior 3.

The hot water heater shown in Fig. 2 is a water heater, which consists of two container parts 1, 2. The first container part 1 (not shown) is designed as a flat circular disk. The second container part 2 has a recess 25 which forms an annular interior for heating water. In the interior, which is delimited by the first container part 1 and the second container part 2, the heating device 4 is arranged in the form of two tubular heating elements 4a and 4b. Depending on the heating output, either only one tubular heating element 4a or both tubular heating elements 4a and 4b are in operation.

The hot water heater has a connecting flange 26 to which a water pipe, not shown, can be connected. The connecting flange 26 is molded directly onto the container part 2, which is preferably made of plastic. A venturi nozzle 24 is provided downstream of the connecting flange 26 in the flow direction of the water. A first branch duct 27, which is connected to a membrane socket 7, is arranged in the inlet region of the Venturi nozzle 24. The first branch duct 27 enters the upper space of the membrane box 7. A membrane 8, not shown, divides the interior of the membrane box 7 into an upper and a lower space. A second branch duct 28 is arranged at the outlet of the Venturi nozzle 24 and is connected to the membrane socket 7. The second branch duct 28 enters the lower space of the membrane box 7. Due to the pressure difference generated in the upper and lower space of the membrane box 7, the membrane 8 is moved. The membrane 8 is connected to at least one electrical switch (not shown), which switches the power supply to the heating device 4.

The water emerging from the outlet of the Venturi nozzle 24 reaches an inflow device 19 via a deflection channel 29. The deflection channel 29, together with the Venturi nozzle 24, is molded directly onto the container part 2. The deflection channel 29 (partially shown in broken lines) extends to the inflow device 19 and is delimited by the two container parts 1, 2. The inflow device 19 is formed as a depression in the container part 2 and forms a branch through which the water is divided into two partial flows. The annular recess 25, which forms the interior of the container 1, 2, is flowed through in two different directions. In the As shown, the water flows counterclockwise in the right side arm of the annular container and clockwise in the left side arm.

In the illustration shown, there is a drainage device 20 in an upper area of the annular interior. If the annular or toroidal container 1, 2 is fastened to a substantially vertical wall like a clock, it is particularly advantageous if this is done heating water from below, that is from an approx. 6 o'clock position, introduced into the annular or toroidal container 1, 2 (inflow device 19) and the outflow device 20 is provided at the top of the container, that is to say in an approx. 12 o'clock position , A suitable arrangement is given, in particular, if the drainage device 20 is provided at a point as high as possible, at least at a point that lies above the heating device 4.

3 shows a perspective view of the embodiment according to FIG. 2. The container part 2 is designed as a one-piece plastic injection molded part. It carries the essential functional components. The interior of the container is formed by the recess 25 in the container part 2. On the lower side in the position shown, the interior is closed by a circular disk-shaped container part 1 (not shown). On the container part 2, the membrane can 7, the Venturi nozzle 24 and an outlet 30 for the heated water are formed by integrally formed further depressions. In addition, a first fastening dome 31 for a power triac (not shown) and a second fastening dome 32 for a thermal sensor (not shown) are molded onto the container part 2. In this variant, the mounting holes 18 for mounting the water heater on a wall are not formed on the container part 1, but on the container part 2. Furthermore, a holding element 33 is molded onto the container part 2, to which a water inlet pipe (not shown) can be attached.

Claims

claims

1. Electric water heater with a container (1, 2), an electric

Heating device (4) for heating water in the container (1, 2) and additional functional components, the container being composed of at least two container parts (1, 2), characterized in that at least the essential functional components of the hot water heater are attached to one of the container parts (1 , 2) are mounted.

2. Hot water heater according to claim 1, characterized in that the heating device (4) is arranged at least partially within the container (1, 2) and at least the section of the heating device (4) arranged in the container (1, 2) is self-supporting.

3. Hot water heater according to claim 1 or 2, characterized in that the

Containers (1, 2) fastening devices (18) for mounting the water heater, in particular on a wall.

4. Hot water heater according to claim 3, characterized in that only one container part (1) has fastening devices (18) for mounting the hot water heater.

5. Hot water heater according to one of claims 1 to 4, characterized in that at least one container part (1) has a section which forms a section of a housing of the hot water heater.

6. Hot water heater according to one of claims 1 to 5, characterized in that the container (1, 2) has means (17) for fastening a device hood (6).

Hot water heater according to one of claims 1 to 6, characterized in that a container part (2), on which functional parts are mounted, in two Components plastic injection molding is performed and has seals for functional components connected to the container interior (3).

8. Hot water heater according to one of claims 1 to 7, characterized in that the interior of the container (1, 2) is annular.

9. Hot water heater according to claim 8, characterized in that the container (1, 2) has an inflow device (19) for water, which is arranged such that in the operating state of the hot water heater, the water (1, 2) substantially opposite the Flows through gravity.

10. A hot water heater according to claim 8 or 9, characterized in that the container (1, 2) has a drainage device (20) for water, which is arranged such that, in the operating state of the hot water heater, air bubbles rising against the force of gravity through the water from the container (1, 2) can be driven out.

11. Hot water heater in particular according to one of claims 8 to 10, characterized in that a branch is provided through which the one

Inflow device (19) incoming water can be divided into two partial flows, for flowing through a container (1, 2) in two different directions.

12. Hot water heater according to claim 11, characterized in that both partial flows are heated.

13. Hot water heater according to one of claims 8 to 12, characterized in that the functional components are arranged on a surface (23) of the container part (1, 2) which is surrounded by the annular interior of the container (1, 2).

14. Hot water heater according to one of claims 1 to 13, characterized in that the hot water heater has a membrane can (7) with two of one

Has membrane (8) separate pressure spaces, the pressure spaces being designed as depressions in two different container parts (1, 2) and the membrane (8) between these two container parts (1, 2) is held. Hot water heater according to one of claims 1 to 14, characterized in that a pressure relief valve (16) is arranged on that container part (1, 2) which is free of the essential functional components.