WO2011069288A1

WO2011069288A1 - Device for heating water and providing a hot water supply, and method for operating such a device

Info

Publication number: WO2011069288A1
Application number: PCT/CN2009/075400
Authority: WO
Inventors: Yanxin Li; Zhang Peng; Weiwei Wang; Markus Koch; Alexandros Zachos
Original assignee: Vorwerk & Co. Interholding Gmbh
Priority date: 2009-12-08
Filing date: 2009-12-08
Publication date: 2011-06-16
Also published as: TWI526657B; TW201139953A; CN102667358B; CN102667358A

Abstract

Device (1) for heating water and providing a hot water supply, with a water tank (2) and a heating means (6) assigned to the water tank (2) for heating a water supply present in the water tank, wherein the water tank (2) has a water supply (12) and a water outflow (10), wherein further the water outflow (10) is both a hot water outflow and a cold water outflow, characterised in that the pipe (11) for the water supply (12) discharges in the pipe (9) for the water outflow (10) and that by shutting off the water outflow (10) downstream of the discharge opening, the water tank (2) can be filled.

Description

DEVICE FOR HEATING WATER AND PROVIDING A HOT WATER SUPPLY, AND

METHOD FOR OPERATING SUCH A DEVICE

FIELD OF THE INVENTION

The invention relates first of all to a device for heating water and providing a warm water supply, having a water tank and a heating means assigned thereto for heating a water supply present in the water tank, wherein the water tank has a water supply and a water outflow, wherein the water outflow is additionally both a hot water outflow and a cold water outflow.

DESCRIPTION OF RELATED ART Devices of the type under discussion are known. These are used in particular in kitchen or bathroom areas to provide hot water, furthermore in particular in connection with a water tapping point, for example a kitchen sink or a wash basin. Devices of this kind comprise a water tank, which is supplied with cold water from the house main supply for providing hot water. The cold water held in the water tank is heated as a result of heating means acting indirectly or directly on the water supply in the water tank to a pre-determined temperature, where appropriate selected by the user. Devices of this kind are furthermore known in the form of so-called under sink water heaters. These essentially provide a hot water supply, wherein the water tank is always full and the heating means holds the water present in the water tank at the pre-determined temperature as a result of temperature detection. Such devices prove to be unfavourable, in particular with respect to their energy efficiency, because regular re-heating of the water present in the water tank takes place as appropriate over a period of hours, without this being needed. Other devices are accordingly designed such that the water tank is only heated when hot water is required. The heating means acting thereupon heats up the quantity of cold water matched to the requirements to a pre-determined temperature. The water tank of such a device is interposed in the standard cold water supply pipe, so that the tank itself more or less represents a part of the pipe. If only cold water is required in the system, this flows through the water supply into the water tank and out of this via the water outflow to the tapping point.

BRIEF DESCRIPTION OF THE INVENTION

With regard to the above described prior art, a technical problem to be addressed by the invention is to further improve a device of the type under discussion with due consideration to favourable energy efficiency.

This problem is solved first of all and essentially by the subject matter of Claim 1, which relies on the fact that the water supply pipe opens into the water outflow pipe and that the water tank can be filled by shutting off the water flow downstream of the discharge opening. The inflowing water flows through the water outflow pipe in the water circuit pipework in the direction of the discharge opening of this pipe. According to this arrangement, a device is created, which constitutes an improvement in terms of energy efficiency. Due to the fact that the water supply pipe opens out in the water outflow pipe, the cold water does not flow through the water tank, at least not directly, when only cold water is being drawn. Rather, this flows directly out of the water supply connected to the domestic water pipe in a bypass mode into the water outflow directly connected to the withdrawal site. By means of the shutoff provided downstream of the discharge opening of the water supply into the water outflow, the water tank can be filled following a corresponding activation of said shutoff. Heating of water and provision of a hot water supply accordingly takes place only when required, preferably by the shutoff being actuated by the user in a targeted manner. In a preferred arrangement this causes a back pressure of the cold water entering through the water supply into the water outflow to be obtained, which back pressure brings about the filling of the water tank. Preferably, after a corresponding heating of the water held in the water tank, following opening of the shutoff this is allowed to flow out via the hot water outflow that also serves as the cold water outflow, wherein the water tank is preferably completely emptied According to this configuration, the water tank is used exclusively on demand for heating a quantity of water preferably selected in advance by the user. This serves to counteract any microbial contamination in particular of the interior surfaces and base areas of the water tank. Further features of the invention are explained below as well as in the description of the figures, and often in their preferred association to the subject matter of Claim 1 or to features of other claims. They can however also be of importance only in association to individual features of Claim 1 or of the respective further claim or independently, respectively.

Thus a further preferred arrangement of the subject matter of the invention provides that the water supply pipe protrudes into the water outflow pipe, this being in such a way as to leave an opening cross-section forming the outflow opening between the water supply and water outflow pipes. In a further preferred arrangement, the water supply pipe protrudes to an axial extent into the water outflow pipe, which axial extent preferably corresponds to a factor of 0.5 to 3 times, more preferably a factor of 1 to 1.5 times that of the outside diameter of the water supply pipe. This further preferably guarantees that in when drawing only cold water this flows in a directed manner through the water supply into the water outflow and is passed via this to the tapping point (bypassing the water tank) . The opening cross-section that is formed between the pipes for the water supply and the water outflow, in a preferred configuration using tubular pipework, is circular in shape. In this case the opening cross-section is further selected in terms of its area such that filling of the water tank is effected via the outflow opening so defined, and furthermore, in such a manner that after appropriate activation of the shutoff the water tank is filled up to to a height to be pre-determined in a reasonable time. Accordingly, the opening cross-section is selected so that, as a result of back pressure, a through passage of water into the water tank with respect to the water flow quantity per unit time corresponds to a factor of 0.3 to 1, more preferably a factor of 0.5 to 0.7 times the water flow quantity per unit time when cold water alone is drawn. As a result, this arrangement facilitates a speedy filling of the water tank. Thus in this context it is further provided that the outside diameter of the water supply pipe opening into the water outflow pipe corresponds to 0.5 to 0.9 times, more preferably 0.7 to 0.8 times, that of the internal diameter of the water outflow pipe. In relation to this it is further preferred that the water supply pipe opens concentrically in the water outflow pipe, so that an annular shaped opening cross-section is formed between the pipes. The outflow opening of the water tank serves as an inlet port in the course of the filling process of said tank. Accordingly, the opening on the water tank side has a double function.

The water supply pipe passes through the water tank in a further preferred arrangement, more preferably with respect to an outline extent of the water tank in a central position. Accordingly, when the water tank is full and during the subsequent heating process, the water supply pipe is surrounded by the medium to be heated, as a result of which an exchange of heat takes place between the water column present in the water supply pipe and the quantity of water admitted into the water tank. Accordingly the water column present in the water supply pipe during the heating process is preferably also brought to the desired temperature at least up to the level of the water level within the water tank. In this case, the water supply pipe, in particular in the area where it penetrates the water tank, is preferably formed from a good heat-conducting material (for example from relatively thin-walled copper or plastic with a wall thickness of, e.g., 1 mm to 2 mm) .

In a further preferred configuration a stop valve is assigned to the water supply pipe. By means of this, the water supply for filling the water tank can be obtained after appropriate closure of the shutoff provided behind the outflow opening of the water tank in the flow direction, by the cold water supply being shut off. This stop valve also allows the corresponding supply to be regulated when only cold water is being drawn.

The additional shutoff downstream of the outlet of the water tank is further preferably formed likewise in the form of a stop valve. This serves, preferably in cooperation with the stop valve of the cold water supply, to fill the water tank and to empty it.

The invention further relates to a procedure for operating a device for heating water and providing a hot water supply, wherein the device has a water tank, a water supply and a water outflow, wherein further the water supply pipe discharges into the water outflow pipe, and a stop valve is provided in the water supply pipe before the discharge in the flow direction and in the water outflow pipe after the discharge opening in the flow direction.

In order to further improve a method of the type under discussion, it is proposed that a filling of the water tank is undertaken by back pressure of the supply water flowing beneath the flow opening into the water outflow pipe as a result of shutting off the water outflow pipe. Accordingly it is preferably provided that to fill the water tank the water outflow serving also as the cold water outflow is shut off, e.g. by appropriate activation of a stop valve. Two stop valves are preferably provided here, one for regulating the cold water supply and one for filling and emptying the water tank, which valves in a further preferred arrangement are coupled together, in particular with respect to the filling and emptying of the water tank. These can furthermore be electromagnetically activatable valves, wherein preferably the actuation of the stop valve causing the back pressure is coupled to an actuation of the stop valve regulating the cold water supply. It is further preferred that on reaching a maximally predefined water level in the water tank an automatic shutoff of the cold water supply is caused by shutting off the corresponding shutoff means. To this end, e.g. appropriate sensors are further provided in the water tank, moreover in a simpler configuration a sensor in the form of a float. The sensor is designed for generating a signal, which in a preferred configuration controls the stop valve in the cold water supply pipe. Moreover the stop valve in the water outflow pipe preferably remains in the closed position. After completion of a hot water or cold water extraction in the open position, hot water is preferably removed completely, so that thereafter the water tank is emptied. The shutoff, particularly in the case of the drawing of cold water, which takes place without rinsing of the water tank, is preferably achieved by closing off the valve arranged in the supply pipe. Accordingly, in a preferred configuration after a corresponding hot or cold water removal the system is in a dry state downstream of the cold water supply valve. No residual amounts of water therefore remain in the water tank, in the section of the supply pipe behind the associated stop valve or in the outflow pipe Alternatively the supply shutoff is effected by closure of both valves, with the valves furthermore preferably being under coupled control . Further features of the invention are explained below as well as in the description of the figures, and often in their preferred association to the subject matter of Claim 6 or to features of other claims. They can however also be of importance only in association to individual features of Claim 6 or the respective further claim or independently, respectively.

Thus, according to the method, it is further provided in a preferred construction that the outflow opening arranged in the water tank upstream of the discharge opening of the water supply pipe into the water outflow pipe is dimensioned such that when only supply water is passing through it, i.e. preferably cold water is passing through it, a suction effect is obtained with respect to the water tank. The cold water flowing through the water supply pipe into the water outflow pipe provides thus provides a so-called water jet pump effect. The water supply pipe in this arrangement protrudes into the water outflow, this being in such a way as to leave a preferably annular opening cross-section forming the outflow opening between the water supply and water outflow pipes. Through this preferably annular opening cross-section, as a result of the effect of negative pressure the flowing supply water drains residual moisture in particular out of the base area of the water tank. The respectively indicated numerical bands also include - unless otherwise indicated in an example - all intermediate values, namely restricted in particular in 1/10 steps from the lower and / or upper limit up to the respective other limit. "And" in this context means that both limits are shifted by one or more tenths towards the limit, i.e. they are curtailed.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention is clarified in more detail on the basis of the enclosed drawing, which represents only one exemplary embodiment. They show:

Fig. 1 in a partially section view a device of the type under discussion in a position with cold water flowing through;

Fig. 2 the enlarged area II in Fig. 1;

Fig. 3 the section along the line 111 - III in Fig. 2;

Fig. 4 a diagram corresponding to Fig. 1, but concerning an intermediate position in the course of filling a water tank;

Fig. 5 a sequential illustration to Fig. 3, concerning the filled position of the water tank;

Fig. 6 the device represented as in Fig. 1, but concerning the outflow of the water stored and heated in the water tank;

Fig. 7 a flow diagram to illustrate the method for operating the device.

List of reference codes:

1 Device

2 Water tank

3 Tank base

4 Tank wall

5 Tank cover

6 Heating means

7 Measurement sensor

8 Outflow opening

9 Pipe

10 Water outflow

11 Pipe

12 Water supply

13 Stop valve

14 Stop valve

15 Actuator unit

16 Level sensor 17 Ventilation opening

a Outside diameter

b Internal diameter

c Immersion distance

X Vertical axis

a angle

G Initial position

K Cold water selector

S choice

W Hot water selector

KW Cold water

WW Hot water

DETAILED DESCRIPTION OF THE INVENTION

Primarily presented and described with reference to Fig. 1 is a device 1 for heating water and providing a hot water supply.

The device 1 has first of all a water tank 2. This possesses a tank base 3 and a surrounding tank wall 4, extending perpendicular to the plane of the base. The latter bears a tank cover 5, spaced vertically apart from the tank base 3, which extends in a plane lying at right angles to the height extension of the tank wall 4.

The water tanks 2 a preferably has a concentric configuration, wherein a vertical axis x of the water tank 2 is aligned parallel to the vertical extent of the tank wall 4. Alternatively the water tank 2 has a polygonal outline, e.g a square .

The tank base 3 extends at an angle to the centre of the ground, this preferably subtending an angle a to a horizontal plain of about 5°. A heating means 6 is arranged on the underside of the tank base 3. In a preferred configuration this takes the form of an electric resistance headier. Further, the heating means 6 preferably has conductor tracks applied on a dielectric forming an isolation layer. These resistive conductor tracks are preferably applied on the dielectric using ceramic pastes by silk-screen printing, wherein further preferably a concentric arrangement of conductor tracks is provided with reference to the vertical axis x. The tank base 3 is further preferably a component of the heating means 6, for which purpose this is constructed of stainless steel plate, on the underside of which the dielectric with the conductor tracks is applied.

To provide temperature regulation, a measurement sensor 7 is further preferably provided in the form of an NTC element with a resistance of e.g. ΙΟ,ΟΟΟΩ. At the centre of the tank base 3 an outflow opening 8 is provided. This is formed by the free interior cross-section of a pipe 9 of a water outflow 10. This water outflow pipe 9 is joined in a sealed manner to the tank base 3 so as to leave the outflow opening 8, wherein a free end of the pipe 9 is flush with the surface of the tank base 3 facing into the tank interior.

The water outflow pipe 9 leads to a water tapping point site, not shown . Further, a pipe 11 is provided for a water supply 12. This pipe 11 is formed, as is also preferably the pipe 9, as a tube with a circular cross-section. The pipe 11 penetrates the water tank 2 centrally, accordingly the pipe axis with coincides with the vertical axis x of the water tank 2. The pipe 11 thus penetrates the tank cover 5 and with its free end facing vertically downwards is immersed into the pipe 9 of the water outflow 10. The outside diameter a of the pipe 11 of the water supply 12 corresponds in the embodiment shown of the pipe 9 of the water outflow 10 to about 0.8 times the free internal diameter. An annular opening cross-section is accordingly formed in the area of the outflow opening 8 in the case of a concentric discharge opening of the pipe 11 in the pipe 9.

The pipe 11 of the water supply 12 is immersed by an amount c into the pipe 9 of the water outflow 10, which amount c corresponds in the embodiment shown to about 1.3 times the outside diameter a of the pipe 11.

Furthermore, a stop valve 13 is provided in the pipe 11 of the water supply 12 in front of the outflow opening 8 in the flow direction. A further stop valve 14 of the same type is positioned downstream in the pipe of 9 the water outflow 10. Both valves in the embodiment shown are constructed as shutoff flaps, but can alternatively also be slider-style and / or adjustable valves for regulating flow rate quantities.

Both stop valves 13 and 14 are further preferably electrically controllable, in particular electromagnetically activated, for which purpose a corresponding actuator unit 15 is provided. This acts on a stop valve, further preferably on both stop valves, wherein the corresponding control can be effected automatically according to given parameters, or alternatively by user intervention . By reference to the flow chart shown in Fig. 7 the procedure for operating the device 1 is described in the following:

The device 1 is interposed between the building cold water supply and the tapping point site, the pipe 11 of the water supply 12 being directly connected to the building cold water supply. The device 1 is further designed so that from the tapping point site either supply water, i.e. usually cold water KW from the building cold water supply, or heated warm water WW in the water tank 2 can be taken from the tapping point site. In the initial position (in the flow chart according to Fig. 7 marked with G) the stop valve 13 and the stop valve 14 are both closed. Starting from this initial position G, the choice is made (symbolised in fig. 7 with S) whether cold or hot water is to be drawn via the tapping point, not shown. Accordingly, different flows are selected K (cold water) and/or W (hot water)

To draw the cold water KW, corresponding to the water flowing into the device 1 via the tapping point, both stop valves 13 and 14 of the pipe 11 for the water supply 12 and the pipe 9 for the water outflow 10 are opened in accordance with the illustration in Fig. 1. The opening of the stop valves 13 and 14 preferably takes place at the same time, due to coupling of the actuation devices acting on the valves, and further preferably via the actuation unit 15, for which the latter has e.g. a corresponding activation button "cold water" . Alternatively, the stop valves 13 and 14 can also be arranged so that these are arranged in proximity to each other, and in a further configuration of the same are e.g. free to be activated manually in the form of sliding valves.

To stop the drawing of cold water, both stop valves 13 and 14 are accordingly closed again. Hereafter the system returns to the initial position G.

To draw hot water WW from the device 1, heating of a pre-defined quantity of water in the device 1 is first of all necessary. To this end, the water tank 2 is first of all filled with inflowing water - here cold water KW . To this end, the stop valve 13 on the water supply side is first of all to be opened from its valve-locked initial position G, this preferably being controlled by the actuator unit 15, or alternatively manually by user intervention. Via the opened stop valve 13, water from the supply - cold water KW - flows through the pipe 11 for the water supply 12 into the pipe 9 for the water outflow 10, is dammed as a result of the closed stop valve 14 on the water outflow side and, upon a further flow of supply water through the annular outflow opening 8 in the base of the water tank 2, enters the tank. The water tank 2 is successively filled , up to a fill level desired by the user, further preferably up to a maximum height, which is monitored by a level sensor 16. If the water level in the water tank 2 reaches a maximum, then an appropriately generated signal from the level sensor 16 triggers a closure of the stop valve 13 on the water supply side.

The air displaced by the water flowing into the water tank 2 during the filling escapes to the outside through a ventilation opening 17 in the cover. The closure of the supply side stop valve 13 is followed by the heating of the water supply stored in the water tank 2 by means of the heating means 6 provided on the base. The temperature is monitored via the measurement sensor 7. If the water temperature that is preset or alternatively pre-selected by the user is reached, then an appropriately generated signal from the measurement sensor 7 leads to the heating means 6 being switched off, whereupon the warm water WW is ready to flow out.

This outflow takes place after opening of the stop valve 14 on the water outflow side. The stop valve 13 on the water supply side remains in the closed position.

The opening of the stop valve 14 can take place automatically, in a self -activated manner, depending on a signal generated by the measurement sensor 7, that the selected water temperature is reached. In a preferred configuration the opening of the water outflow side stop valve 14 takes place due to user intervention, this being done manually if the valve is configured as e.g. a slider valve, but more preferably automatically as a result of the pressing of a button or the like in the area of the actuator unit 15.

Owing to the tank base 3 being formed with a slope towards the outflow opening 8, after opening of the stop valve 14 the entire contents of the water tank 2 runs out, preferably leaving no residue, whereupon in order to attain the initial position G of the device 1 the stop valve 14 is finally closed off again.

Any remaining moisture within the water tank 2, in particular resting on the tank base 3, is removed as part of a subsequent drawing of cold water as a result of a suction effect. The water from the supply flowing through the pipe 11 for the water supply 12 into the pipe 9 for the water outflow 10 acts in this context in the manner of a water jet pump, wherein a negative pressure via the annular opening cross-section of the outflow opening 8 acts at least on the immediate surroundings of the base of the outflow opening 8.

All disclosed features are (per se) essential to the invention. The disclosure of the application hereby also incorporates by reference the disclosed content of the associated/enclosed prior art documents in full (copy of the advance application) , also for the purpose of jointly incorporating features of these documents into claims of the present application. The dependent claims characterise, in their optionally coordinated drafting, independent inventive extensions of the prior art, in particular in order to make partial applications based on these claims.

Claims

1. Device (1) for heating water and providing a hot water supply, with a water tank (2) and a heating means (6) assigned to the water tank (2) for heating a water supply present in the water tank, wherein the water tank (2) has a water supply (12) and a water outflow (10), wherein further the water outflow (10) is both a hot water outflow and a cold water outflow, characterised in that the pipe (11) for the water supply (12) discharges in the pipe (9) for the water outflow (10) and that by shutting off the water outflow (10) downstream of the discharge opening, the water tank (2) can be filled.

2. The device according to Claim 1 or in particular thereto, characterised in that the pipe (11) for the water supply (12) protrudes into the pipe (9) of the water flow (10) , in such a way as to leave an opening cross-section forming the outflow opening (8) between the pipes (9, 11) for the water supply (12) and the water outflow (10) .

3. The device according to one or more of the preceding claims or in particular thereto, characterised in that the pipe (11) for the water supply (12) ends concentrically in the pipe (9) for the water outflow (10) .

4. The device according to one or more of the preceding claims or in particular thereto, characterised in that the pipe (11) for the water supply (12) penetrates the water tank (2) .

5. The device according to one or more of the preceding claims or in particular thereto, characterised in that a stop valve (13) is assigned to the pipe (11) for the water supply (12) .

6. A method for operating a device (1) for heating water and providing a hot water supply, wherein the device has a water tank (2), a water supply (12) and a water outflow (10) , wherein further the pipe (11) for the water supply (12) discharges in the pipe (9) for the water outflow (10) and a stop valve (13) is provided in the pipe (11) for the water supply (12) before the discharge opening in the flow direction and a stop valve (14) in the pipe (9) for the water outflow (10) after the discharge opening in the flow direction, characterised in that filling of the water tank (2) is undertaken by back pressure of the supply water flowing beneath the outflow opening (8) into the pipe (9) of the water outflow as a result of shutting off the pipe (9) for the water outflow (10) . The method according to Claim 6 or in particular thereto, characterised in that the outflow opening (8) arranged downstream of the discharge of the pipe (11) for the water supply (12) into the pipe (9) for the water outflow (10) is dimensioned such that when only supply water is passing through it, a suction effect is obtained with respect to the water tank (2) .