EP2598809B1 - Protective device, instantaneous water heater and fluid reservoir - Google Patents

Description

The present invention relates to a protective device for a fluid-carrying device for protection against fluid leakage in the event of damage to a fluid-carrying device section, a water heater with such a protective device and a fluid reservoir, with such a protective device.

In continuous-wave heaters in bare-wire technology with a plastic-based heating block, water damage can occur, for example due to a bursting of the heating block. To protect against such damage therefore so-called protective devices are usually integrated into the respective fluid-carrying device. A known protective device is integrated, for example, in an electric instantaneous water heater in the DE 41 03 373 A1 shown. The water heater is designed in bare wire technology and has a heating block in which a meandering heating channel is formed, which communicates with a cold water inlet and a hot water drain. For heating the water, a plurality of electrical heating coils is installed in the heating channel, which are energized upon actuation of an electrical switch of the water heater and thereby emit the resulting heat to the water flowing around them. In order to prevent the heating coils from being energized in the event of damage to the electrical switch or triac, even though the switch should actually be in the "off" state, a protective device is provided which disconnects the heating coils or the continuous-flow heater from the power supply on all poles. This prevents the heater from causing a user-unrecognized short circuit, which can lead to corrosion and, after some time, to leaks in the heating block. A disadvantage of this protective device, however, is that it prevents water leakage only in so far as that corrosion is prevented. A water outlet from a burst but electrically functional heating block is not prevented.

Furthermore, from the WO99 / 51902A1 a shut-off valve system is known, which regulates a fluid supply line to a fluid reservoir. The shut-off valve system is controlled by a differential pressure between the fluid reservoir and the fluid supply line. A lower pressure in the fluid reservoir than in the fluid supply leads to the closing of the Shut-off valve system. In this case, however, for example, a temperature difference between the fluid reservoir and the supply line can lead to a pressure difference, which thus erroneously blocks the supply line.

This document discloses a protective device according to the preamble of claim 1.

The object of the present invention is to provide a protective device for a fluid-conducting device which eliminates the aforementioned disadvantages and effectively prevents fluid leakage in the event of damage or bursting of a fluid-conducting device section, a flow heater with such a protective device and a fluid reservoir with such a device To provide protection device.

This object is achieved by a protective device having the features of patent claim 1, by a water heater having the features of claim 10 and by a fluid reservoir having the features of claim 11. Advantageous embodiments and refinements which are individually or in combination replaceable are Subject of the respective dependent claims.

A protective device according to the invention for a fluid-carrying device for protection against fluid leakage in case of damage to a fluid-conducting device section has a shut-off valve for arrangement in the fluid inlet of the device, which is in a basic position in the closed position, a bypass line for establishing a fluid connection upstream of the shut-off valve from the fluid inlet to the fluid outlet of the Device parallel to the fluid-conducting device section, and a check valve for arrangement upstream of the bypass line in the fluid drain and prevents the outflow of the fluid from the bypass line in the direction of the damaged device section via the fluid drain.

The solution according to the invention prevents, especially in the unguarded and switched off or idle state of the device effectively and automatically a fluid outlet from the fluid-conducting device section to which the bypass line extends parallel, regardless of whether the device is energized or not. It can maximally escape the fluid that was in the damaged device section at the time of bursting. However, this amount is relatively low and thus leads to no significant fluid damage. In the case of a liquid fluid such as water, a water damage is thus prevented. In the case of a gaseous fluid thus the danger of poisoning, explosion, deflagration and drgl. Depending on the gas is prevented. In addition, the protection device has relatively few components, making it relatively susceptible to interference, low maintenance, easy to install and inexpensive.

In a preferred embodiment, the bypass line has a smaller passage area than the fluid inlet and the fluid outlet. This prevents that an excessive amount of the fluid is guided past the fluid-carrying device section in the fluid drain, which would, for example, adversely affect the heating performance of a water heater.

In a preferred embodiment, a switching unit for generating a switching signal for opening the shut-off valve is arranged in the bypass line. The arrangement of the switching unit in the cross-section tapered bypass line prevents occurring in the fluid inlet pressure fluctuations are detected by the switching unit and reported to the shut-off valve, which would then change its respective working position, so that the protection device is relatively robust.

In one embodiment, the switching signal is reported directly to the shut-off valve, whereby this embodiment is particularly simple and inexpensive to produce.

In another embodiment, the switching signal is processed via at least one installed electronics and then reported to the shut-off valve. The electronics can amplify the switching signal and thus increase the sensitivity of the protective device or, for example, act as a filter that detects faulty switching signals and does not forward them to the shut-off valve. For example, two electronics may be provided, wherein the switching unit passes the switching signal to a first electronics and this then forwards the switching signal to an electronics for switching the shut-off valve.

In another embodiment extends from the bypass line to the shut-off valve, a pressure signaling line for forwarding one in the bypass line occurring pressure drop to the shut-off valve. The pressure signaling line has a correspondingly small flow cross section and eliminates the use of the aforementioned switching unit.

A preferred shut-off valve is a solenoid valve. Solenoid valves are not susceptible to interference, correspondingly low maintenance and compact.

The check valve arranged in the fluid outlet is preferably a directional valve, in particular a non-return valve spring-biased in the direction of the heating block into its closed position. The check valve does not require a separate switching signal to the opening and is also maintenance-free. It is only interpreted the spring in terms of acting on its valve body opening pressure, which is generated by the effluent from the fluid-carrying device portion fluid.

A preferred instantaneous water heater is equipped with the protective device according to the invention. The shut-off valve is preferably arranged in the cold water inlet and the check valve in the hot water drain. The bypass line then extends parallel to the heating block, so that when the bursting of the heating block only the water that was in it was able to escape, since over the shut-off valve and the check valve, a subsequent flow of fresh water is prevented in the heating block.

A preferred fluid reservoir is a hot water tank, wherein the shut-off valve is preferably in the cold water inlet and the check valve in the hot water drain. The bypass line then extends parallel to the storage container, so that when the storage container bursts only the water can escape that was in it, as via the shut-off valve and the check valve, a subsequent flow of fresh water is prevented in the storage container.

The present invention is particularly suitable for the provision of a water heater or a domestic hot water storage in the unguarded and off state or rest state effectively and automatically prevents fluid leakage from the heating block or storage tank, regardless of whether the water heater or the Hot water tank is energized or not.

Other advantageous embodiments of the present invention are the subject of further subclaims. In the following, a preferred embodiment of the invention is explained in more detail with reference to a schematic representation. The only FIG. 1 shows a schematic structure of a flow heater according to the invention.

FIG. 1 shows a structure of a water heater 1 according to the invention for heating water, which is pressure-resistant and preferably carried out in bare-wire technology. It has a heating block 2 in which a meandering heating channel, not shown, is formed with a plurality of heating coils for heating the water. The water to be heated is supplied to the heating block 2 via a cold water inlet 4. The heated water is taken from the heating block 2 via a hot water drain 6, in which a hot water fitting 8 is arranged at a portion remote from the heating block 2, which is opened by an operator to remove the warm water.

According to the invention, the instantaneous water heater 1 has a protective device 10, by means of which it is prevented that water escapes from the heating block 2 in the event of damage, particularly in the unguarded and switched-off state. The protection device 10 has a cold water side check valve 12, a hot water side check valve 14, a bypass line 16, and a bypass line side switching unit 18.

The shut-off valve 12 is arranged in the cold water inlet 4 and preferably a solenoid valve, which is transferred via an actuating unit 20 from its basic position to a working position. In its basic position, which corresponds to its closed position, the solenoid valve 12 is closed and thus the cold water inlet 4 is controlled. In its working position, the shut-off valve 12 is opened and thus the cold water inlet 4 is turned on, so that water to be heated can flow into the heating block 2.

The check valve 14 is arranged in the hot water drain 6 and preferably a directional valve, in particular an automatic check valve. It has a valve body 22 which is biased by a spring 24 against a valve seat 26 to a home position. The check valve 14 is oriented in the cold water inlet, that in its basic position, which corresponds to a closed position, the hot water drain 6 is blocked in the direction of the heating block 2. Opened and thus transferred to its working position, the check valve 14 is generated via the voltage applied to the valve body 22 and generated by the effluent from the heating block 2 warm water opening pressure.

The bypass line 16 establishes a fluid connection between the cold water inlet 4 and the hot water outlet 6 parallel to the heating block 2. It engages upstream of the solenoid valve 12 and downstream of the check valve 14 to the cold water inlet 4 and the hot water drain 6 and has a flow cross-section which is substantially smaller than the cold water inlet 4 and the hot water drain 6.

The switching unit 18 is associated with the bypass line 12 and has a switch 28 and an unnumbered valve, which is arranged in the bypass line 12 via a spring 30 biased into its rest position valve body 32. The position of the valve body 32 is reported via a control line 34 from the valve to the switch 28, which generates a switching or opening signal and this passes on a signal line 36 to the actuator unit 20 for opening the solenoid valve 12.

In the off state of the water heater, the hot water fitting 8 is closed and the water in the bypass line 16 can not flow in the direction of the hot water fitting 8. Likewise, the water can not flow out through the check valve 14 in the direction of the heating block 2, since this blocks in the direction of the heating block 2. Thus, no flow can form in the bypass line 16 and the valve body 22 remains in its rest position. Consequently, the switch 28 does not generate a switching signal for the solenoid valve 12, so that this remains in its closed position and the cold water inlet 4 is not aufsteuert.

When the flow heater is switched on, the hot water fitting 8 is opened by the operator. The water in the bypass line 16 flows through the hot water fitting 8 and via the cold water inlet 4 fresh water flows into the bypass line 16. Consequently, a flow is formed in the bypass line 16, which causes the valve body 32 of the switching unit 18 is transferred against its spring bias from a rest position to its switching position. The switching position is over the control line 34 is signaled to the switch 28, which sends a corresponding switching signal to the actuating unit 20 via the signal line 36, whereupon the solenoid valve 12 is transferred to its open position and the cold water inlet 4 is opened in the direction of the heating block 2. Now, the fresh or to be heated water flows through the open solenoid valve 12 in the heating block 2, is heated there and exits through the hot water drain 6 from the heating block 2. It flows against the located in its closed position valve body 22 of the check valve 14 and acts on it with such pressure that it opens against its spring bias and thus the warm water flows through the check valve 14 through the heating water drain 6 in the direction of the hot water fitting 8 and there Flow heater 1 can be removed.

If there is now damage to the flow heater 1 in the form of a burst heating block 2, a cold water inlet section 38 arranged between the solenoid valve 12 and the heating block 2 or a hot water drain section 40 arranged between the heating block 2 and the check valve 14, the flow heater 1 occurs depending on the installation position located in this device area 2, 38, 40 downstream of the check valve 12 and upstream of the check valve 14 located water from the water heater 1 from. However, this amount of water is very low, so that there is no major water damage.

Is the water heater in case of damage in the unguarded idle state, the Heizwasserarmatur 8 is controlled. Likewise, the check valve 14 is locked in the direction of the heating block 2. Thus, no flow can form in the bypass line 16 and the solenoid valve 12 is not turned on. Thus, neither via the cold water inlet 4 still on the Heizwasserablauf 6 fresh water in the damaged equipment area 2, 38, 40 flow and exit there.

Is the water heater in case of damage in the on state or it is turned on despite damage, the Heizwasserarmatur 8 is opened and the water in the bypass line 16 flows through the Heizwasserarmatur 8. Fresh water flows via the cold water inlet 4, whereupon the valve body 32 is transferred from its rest position to its switching position and the switching unit 18 sends an opening signal to the actuating unit 20 of the solenoid valve 12, so that this opens the cold water inlet 4. Due to the damage, however, at least a certain amount of water to be warmed or heated water exits upstream of the check valve 12, whereby the removable at the Heizwasserarmatur 8 amount of water, for example, and / or not warmed to a set target temperature. The operator registers this and closes the Heizwasserarmatur 8, whereupon the flow in the bypass line 16 collapses, the solenoid valve 12 the cold water inlet 4 is heading and no fresh water in the damaged device area 2, 38, 40 flow and thus can escape from the water heater 1. Even assuming that the water pressure applied to the check valve 14 is sufficient to open it, the actual amount of water that can be taken out of the hot water fitting 8 does not correspond to the target amount of water. The operator notices this and also closes the hot water faucet.

Disclosed is a protective device for a fluid-carrying device for protection against fluid leakage in case of damage to a fluid-conducting device section, with a shut-off valve for placement in the fluid inlet of the device, which is in a basic position in the closed position, a bypass line for establishing a fluid connection upstream of the shut-off valve from the fluid inlet to Fluid flow of the device parallel to the fluid-conducting device section, and with a check valve upstream of the bypass line in the fluid drain and prevents leakage of the fluid from the bypass line in the direction of the damaged device section via the fluid drain, a water heater and a fluid reservoir, each having such a protection device.

LIST OF REFERENCE NUMBERS

1

Heater

2

heating block

4

Cold water supply

6

Hot water outlet

8th

fitting

10

guard

12

shut-off valve

14

check valve

16

bypass line

18

switching unit

20

operating unit

22

valve body

24

feather

26

valve seat

28

switch

30

feather

32

valve body

34

control line

36

signal line

38

Cold water inlet section

40

Heizwasserablaufabschnitt

Claims (11)

1. Protective device (10) for a fluid-conducting device (1) for protection against the escape of fluid in cases of damage to a fluid-conducting device section (2, 38, 40), wherein the protective device (10) has a cutoff valve (12) for arrangement in the fluid inflow (4) of the device (1), which is in the closed position in its normal position, and a line (16),
   and the protective device (10) through a stop valve (14) for arrangement upstream of the line (16) in the fluid outlet (6) and which prevents a dispersal of fluid from the line (16) in the direction of the damaged device section (2, 38, 40) via the fluid outlet (6), characterised in that
   the line (16) is a bypass line (16) for producing a fluid connection upstream of the cutoff valve (12) from the fluid inlet (4) to the fluid outlet (6) of the device (1) parallel to the fluid-conducting device section (2, 38, 40).
2. Protective device according to claim 1, wherein the bypass line (16) has a smaller pass-through cross section than the fluid inlet (4) and the fluid outlet (6).
3. Protective device according to claim 1 or 2, wherein a switch unit (18) for generating a switching signal for opening the cutoff valve (12) is arranged in the bypass line (16).
4. Protective device according to claim 3, wherein the switching signal can be reported to the cutoff valve (12) directly.
5. Protective device according to claim 3 or 4, wherein at least one electronic entity for directly reporting the switching signal to the cutoff valve (12) is provided.
6. Protective device according to claim 1 or 2, wherein a pressure alarm line (36) for transferring a drop in pressure in the bypass line (16) to the cutoff valve (12) extends from the bypass line (16) to the cutoff valve (12).
7. Protective device according to one of the preceding claims, wherein the cutoff valve (12) is a magnet valve.
8. Protective device according to one of the preceding claims, wherein the stop valve (14) is a direction valve, which is closed off in the direction of the fluid-conducting device section (2, 38, 40).
9. Protective device according to claim 8, wherein the stop valve (14) is a spring-pretensioned non-return valve.
10. Continuous flow heater (1) having a protective device (10) according to one of the preceding claims.
11. Fluid reservoir having a protective device (10) according to one of claims 1 to 9.

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