EP4105396B1 - Drinking and domestic water system - Google Patents

Description

The present invention relates to a drinking and service water system that is designed as a cold water system and has a connection to the public water supply network. At least one supply line leading to at least one consumer is fed with fresh water via the connection to the public water supply network. Unused water is returned in a circulation line and with a circulation pump assigned to the circulation line and cooled in a cooling device. To drain water from the drinking and service water system, a flushing valve is provided downstream of the consumer in the direction of flow.

Such a drinking and service water system, for example, is out DE 10 2019 217 903 A1 known. There is also a drinking water circulation device for cooling drinking water EP 3 712 337 A1 known.

Out of DE 100 57 578 A1 a device with solar collectors is known, which are installed on a flat roof of a house with a room to be air-conditioned. The solar collectors are connected by a flow line and a return line, which form a first heat transfer fluid circuit with a first circulation pump, to a solar heat exchanger, which releases the solar heat to a heat transfer medium in a heat storage. The heat storage is connected to a second heat transfer fluid circuit with a second circulation pump and an evaporative cooler, which is also arranged on the flat roof of the house. A third circulation pump conveys heating or cooling water from the heat storage through a wall heating and/or heating and cooling ceiling of the room to be air-conditioned. This is how the room should be heated or cooled. Furthermore, the DE 100 57 578 A1 proposes to use excess solar heat to distill seawater for the purpose of producing drinking water.

With that out DE 10 2019 217 903 A1 In the well-known drinking and industrial water system, in order to maintain drinking water hygiene, water is drained from the drinking and industrial water system via the flush valve in a time-controlled manner, depending on consumption or temperature, and is replaced by fresh water from the public water supply network. The drained water is disposed of through a sewer pipe.

The previously known provision of drinking and industrial water that is as germ-free as possible leaves room for improvement. The present invention aims to provide a drinking and service water system of the type mentioned at the beginning with reduced operating costs.

The present invention is based on the object of specifying a more efficient drinking and industrial water system for providing drinking and industrial water that is as germ-free as possible.

To solve this problem, the present invention proposes a drinking and service water system with the features of claim 1. This is characterized by the fact that the cooling device is designed to cool by evaporating water drained from the drinking and service water system. As a result, the water that was disposed of unused in the prior art is used for cooling the drinking water and electrical energy for cooling the drinking water is saved. The evaporation cold created during evaporation is used to cool the drinking water.

The circulation line of the drinking and service water system usually flows back into the supply line. In this way, the drinking water can circulate in the drinking and service water system when the consumer is not tapping and germ formation due to standing water can be avoided. The cooling device usually cools the water to temperatures below 25°C and preferably below 20°C in order to avoid the formation or proliferation of legionella and other germs, which is favored in a temperature range between 25°C and 55°C .

The circulation flow is generally lower than a supply flow triggered by a consumer's tapping process. The circulation line accordingly preferably has a nominal diameter that is at least one step smaller than the supply line. The circulation line can, for example, have a nominal diameter of DN 15 or smaller and the supply line can have a nominal diameter of DN 20 or larger.

Preferably, time-controlled, consumption or temperature-dependent water is drained from the drinking and service water system via the flushing valve and replaced with fresh water from the public water supply network. As a rule, a control unit is provided which is connected to the flushing valve in terms of control. The flushing valve is usually assigned to a flushing line branching off from the circulation line.

According to a preferred development of the present invention, the cooling device comprises a heat exchanger which is preferably arranged downstream of the branch to the flushing line in the flow direction and which is connected to a coolant circuit which communicates with an evaporation device in which the drained water removes heat from the coolant by evaporation. The heat dissipated in this way is released into the environment through the evaporated water.

The heat exchanger is usually provided with a return connection for the introduction of drinking water returned from the circulation line and a flow connection for the delivery of the cooled drinking water. The flow connection is connected directly or indirectly to the supply line. The supply line usually forms the circulation line and the cooling device has a drinking water circuit for circulating and cooling the drinking water. The heat exchanger usually has a separate return connection and a separate flow connection for the coolant. Preferably, the coolant circuit forms the primary circuit of the heat exchanger and the drinking water circuit forms the secondary circuit of the heat exchanger. The heat exchanger can be designed as a plate heat exchanger.

The evaporation device is preferably designed as a refrigeration machine based on evaporative cooling. Energy is removed from the coolant in the form of heat through the evaporation of the drained water.

In the drinking and service water system according to the invention, a water/glycol mixture is preferably used as a coolant. This ensures the functionality of the coolant in winter at temperatures below 0°C. Furthermore, an installer who puts the coolant circuit into operation does not need to have any special qualifications for handling coolants that are harmful to health or have an adverse effect on the environment (refrigerant certificate). In addition, glycol is in liquid class 3, so that the heat exchanger only has to separate the drinking water to be cooled from the coolant with a single wall. This reduces the size and the costs of manufacturing the heat exchanger. Furthermore, this improves the heat transfer between the coolant circuit and the drinking water circuit within the heat exchanger.

As a rule, the coolant circuit is assigned a coolant circulation pump for circulating the coolant between the heat exchanger and the evaporation device.

According to a further preferred development of the present invention, the evaporation device is arranged to release evaporated water into the environment. The water vapor created during evaporation is absorbed into the ambient air. The ambient air is preferably air from outside. In particular, the evaporation device can be provided outdoors or in a greenhouse.

According to a further preferred development of the present invention, the drinking and service water system comprises a water tank for temporarily storing drained water and a pump that pumps water from the water tank into the evaporation device.

The cooling requirements of drinking water are subject to natural fluctuations, particularly due to the different temperatures over the seasons. For example, the cooling requirement may be highest in summer, while there is usually little or no cooling requirement in winter. The water tank is preferably used primarily in summer in order to always have enough drained water available for the evaporation device and to meet the cooling needs. Under certain circumstances, the cooling requirement can even be greater in winter if the drinking water pipes are partially installed close to the heating pipes and the drinking water can heat up as a result. In winter, the coolant in the evaporation device can be cooled additionally or exclusively by cold air, preferably cold outside air. In particular, if the temperatures of the ambient air of the evaporation device reach or fall below approximately 0 ° C, no water is supplied to the evaporation device in order to avoid damage to the evaporation device due to icing.

The water tank preferably includes an additional connection for introducing rainwater. During or before a period of hot days, this connection can be opened to better cover peak cooling requirements. In winter, the mechanism for evaporating water in the evaporation device can be put out of operation and the water drained via the flush valve can be disposed of through a sewer pipe as is known in the art. If the drinking water needs to be cooled or is necessary in winter, the coolant can be cooled by the cold air from outside and due to the lower temperature of the outside air.

According to a further preferred development of the present invention, the drinking and service water system has a switching device for switching between a summer cooling mode, in which heat is removed from coolant by evaporation of drained water, and a winter cooling mode, in which coolant is cooled by cold outside air.

According to a further preferred development of the present invention, the drinking and service water system comprises a control unit connected to the flushing valve with a temperature-controlled flushing mode, in which a measured water temperature in the cold water system is used as a controlled variable to control the flushing valve, and/or with a flushing quantity-controlled Flushing mode, in which a measured amount of water drained from the cold water system via the flushing valve is used as a controlled variable to control the flushing valve, and/or with a time-controlled flushing mode, in which a specific time or a period of time is used as a controlled variable to control the flushing valve.

Several of the control unit modes mentioned can be activated at the same time. For example, the control unit can always control the flushing valve at a specific time of day or night when the time-controlled mode is activated. When the temperature-controlled flushing mode is activated, the control unit can control the flushing valve if or as soon as a measured water temperature of the cold water system falls below a predetermined target temperature. When the flushing quantity-controlled mode is activated, the control unit can control the flushing valve if or as soon as a value measured in a certain time interval by the The amount of water drained from the cold water system via the flushing valve falls below a predetermined target amount.

Fig. 1

eine schematische Darstellung eines ersten Ausführungsbeispiels und

Fig. 2

eine schematische Darstellung eines zweiten Ausführungsbeispiels.

Further details and advantages of the present invention result from the following description of exemplary embodiments in conjunction with the drawing. In this show:

Fig. 1

a schematic representation of a first exemplary embodiment and

Fig. 2

a schematic representation of a second exemplary embodiment.

The Figures 1 and 2 each show a drinking and service water system of a building 2 in a schematic representation. The drinking and service water system is designed as a cold water system and has a connection 4 to the public water supply network. A supply line 6 is fed with fresh drinking water via connection 4 to the public water supply network. The supply line 6 supplies a consumer 8 connected to it with fresh drinking water. The consumer 8 can be realized by a kitchen sink, a washbasin, a shower, a bathtub or a toilet.

The consumer 8 is connected to a circulation line 10 for returning unused drinking water. The circulation line 10 is assigned a cooling device 12 for cooling the unused drinking water and a circulation pump 14. The supply line 6, the circulation line 10, the cooling device 12 and the circulation pump 14 form a drinking water circuit. The circulation pump 14 circulates the drinking water in this drinking water circuit, while the cooling device 12 cools the drinking water.

The cooling device 12 includes a heat exchanger 16, the secondary circuit of which is formed by the drinking water circuit. The primary circuit of the heat exchanger 16 is formed by a coolant circuit 18 which communicates with an evaporation device 20. Water evaporates in the evaporation device 20 and is drained from the drinking and service water system by a flushing valve 22 which is downstream of the consumer 8 in the direction of flow and is assigned to a flushing line 21 branching off from the circulation line and is fed to the evaporation device 20 via a feed line 24. During evaporation, heat is removed from the coolant. The water vapor created during evaporation is absorbed into the ambient air.

The coolant circuit 18 is assigned a coolant circulation pump 26, which allows the coolant to circulate between the heat exchanger 16 and the evaporation device 20. The evaporation device 20 is here arranged outdoors.

The first and second embodiments differ in how the water drained through the flush valve 22 is supplied to the evaporation device 20.

According to the in Figure 1 First exemplary embodiment shown, the drinking and service water system includes a water tank 28 for temporary storage of the water through the flushing valve 22 drained water and a pump 30 that pumps water from the water tank 28 into the evaporation device 20. The pump 30 is operated predominantly in summer and only when outside temperatures are higher than 0°C, while the pump 30 is out of operation in winter when outside temperatures are approximately 0°C or less. A drain valve 32 of the water tank can remain open in winter. The drain valve 32 drains into a sewer line 34. This means that the water tank 28 can remain empty in winter. However, it can also remain filled and be automatically emptied from time to time. The flushing valve 22 and the drain valve 32 are each assigned a free outlet 36 above a drainage object in accordance with DIN EN 1717.

This in Figure 2 The second exemplary embodiment shown differs from the first exemplary embodiment in that the water drained through the flushing valve 22 is not temporarily stored. Instead, the flush valve 22 drains the water directly into the evaporation device 20. In the second exemplary embodiment, the flushing valve 22 is preferably designed as a two-way valve, so that the flushing valve 22 can also drain water directly into the wastewater line 34 if, for example, there is no need for cooling.

Reference symbol list

2

Building

4

Connection to the public water supply network

6

supply line

8th

consumer

10

Circulation line

12

Cooling device

14

Circulation pump

16

Heat exchanger

18

Coolant circuit

20

Evaporation device

21

Flushing line

22

Flush valve

24

feed line

26

Coolant circulation pump

28

water tank

30

pump

32

drain valve

34

sewer pipe

36

free outlet over a drainage object

Claims (8)

1. A potable and non-potable water system which is configured as a cold water system, having:

   a connection (4) to the public water supply mains, via which at least one supply line (6) which leads to at least one consumer (8) is fed with fresh water, a circulation line (10) and a circulation pump (14) arranged in the circulation line (10) for returning unconsumed water, a cooling means (12) for cooling the unconsumed water, and a flushing valve (22) which is located downstream from the consumer (8) in the direction of flow for discharging water from the potable and non-potable water system,

   characterised in that the cooling means (12) is configured to be adapted for cooling by evaporation of water discharged from the potable and non-potable water system.
2. A potable and non-potable water system according to claim 1, characterised in that the cooling means (12) comprises a heat exchanger (16) which is connected to a coolant circuit (18) which communicates with an evaporation device (20) in which the discharged water gives off heat to the surroundings by evaporation.
3. A potable and non-potable water system according to claim 2, characterised in that the flushing valve (22) is associated with a flushing line (21) which branches off from the circulation line (10), and in that the heat exchanger (16) is located downstream from the branch to the flushing line (21) in the direction of flow.
4. A potable and non-potable water system according to claim 1, 2 or 3, characterised in that the evaporation device (20) is arranged to give off evaporated water to the surroundings, in particular is arranged in the open or in a greenhouse.
5. A potable and non-potable water system according to one of claims 2 to 4, characterised by a water tank (28) for temporarily storing discharged water and a pump (30) which pumps water out of the water tank (28) into the evaporation device (20).
6. A potable and non-potable water system according to one of claims 2 to 5, characterised in that the coolant circuit carries a water/glycol mixture as coolant.
7. A potable and non-potable water system according to one of claims 2 to 6, characterised by a switching device for switching between a summer cooling mode, in which heat is dissipated from coolant by evaporation of discharged water, and a winter cooling mode, in which coolant can be cooled by cold external air.
8. A potable and non-potable water system according to one of the preceding claims, characterised by a control unit, connected for control purposes to the flushing valve, having a temperature-controlled flushing mode, in which a measured water temperature in the cold water system is used as a controlled variable for controlling the flushing valve, and/or having a flushing mode controlled by flushing quantities, in which a measured quantity of water discharged from the cold water system via the flushing valve is used as a controlled variable for controlling the flushing valve, and/or having a time-controlled flushing mode in which a specific time or a time interval is used as a controlled variable for controlling the flushing valve.

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