METHOD FOR OPERATING A RESIDENTIAL STATION AND A RESIDENTIAL STATION FOR THAT PURPOSE

Description

[0001] The invention relates to a method for operating a home station with connections for hot water, a heating circuit and a heating water circuit which is coupled to a central heat generation device, wherein the heating water flows through a heat exchanger to generate hot water and a hot water priority circuit switches off a heating circuit by means of a valve unit when hot water is drawn off, and to a home station for this purpose.

[0002] In multi-family buildings, there are essentially two different options for supplying individual apartments with heating and hot water. In conventional systems, the apartments are supplied directly from a central boiler and a drinking water heater (storage tank) via separate heating and hot water pipes. With an apartment station, there is central heat generation as well as a distribution line for heating and cold water. Hot water is prepared decentrally in the apartments in the apartment stations, which include a plate heat exchanger.

[0003] A familiar domestic hot water station is used to supply a residential unit, particularly in an apartment building, with hot water and heating water. The domestic hot water station is provided with a cold water inlet, a heating water inlet, and a heating water return for connection to a domestic supply network. The domestic hot water is heated using the flow principle via a heat exchanger, particularly a stainless steel plate heat exchanger, and a pressure-controlled proportional flow controller to provide priority for the hot water.

[0004] When hot water is requested by opening a tap, a pressure drop occurs at the proportional flow controller, and the pressure-controlled proportional flow controller switches to hot water priority mode. The heating water flows through the heat exchanger and the proportional flow controller in such a way that the cold water is heated and available as hot water. All of the thermal energy is available for hot water preparation. Once the tap has been closed, i.e., the domestic hot water is withdrawn, the proportional flow controller closes and prevents further heating of the heat exchanger. During heating operation, heating water flows via the heating water flow into the apartment's heating circuit flow, and the proportional flow controller opens the path of the heating circuit return to the heating water return.

[0005] The pressure-controlled proportional flow regulator is proving to be problematic because, due to its design, it is prone to calcification and leakage, thus causing malfunctions.

[0006] EP 0 060 011 A1 discloses a heating control unit for a central heating system and for the provision of hot water in an apartment.

[0007] The invention is based on the object of creating a method for operating a home station and a home station with a hot water priority circuit of the type mentioned above, which avoids the use of the disadvantageous proportional flow controller while maintaining the advantages mentioned.

[0008] According to the invention, the object of the method is achieved in that a return temperature is detected at the heat exchanger and, when a predetermined return temperature is reached at the valve unit, a heating return of the heating circuit is closed.

[0009] In a home station, the task is solved by assigning a temperature sensor to the heat exchanger, which is coupled to the valve unit in such a way that when a predetermined temperature in a heating return line is detected by the temperature sensor, the valve unit closes a heating return line of the heating circuit.

[0010] It has been determined that a temperature drop at the heat exchanger, which is detected on a return line of the heat exchanger and leads to the reaching of a predetermined temperature, which is also referred to as a limit temperature in the context of the present invention, indicates that hot water is being drawn off. When a larger amount of hot water is drawn off, the known hot water priority circuit is advantageous. This circuit ensures that all heating water from the heating water generator is directed through the heat exchanger to temper the hot water. During this time, the heating circuit, to which, for example, an underfloor heating system, at least one radiator, or the like is connected, is shut off so that no heating water flows through the heating circuit.Of course, it is possible for the flow rate of the return to be changed depending on the detected temperature, so that a small temperature change in the return is accompanied by either no or a small change in the flow cross-section, in order to thus also achieve a corresponding change in the thermal energy available for hot water preparation, which is provided or transported by the heating water to the heat exchanger.

[0011] In contrast to the conventional procedure, in which a pressure drop is detected at a proportional flow controller and the hot water priority is implemented at this proportional flow controller, the arrangement of the temperature-controlled valve block is less prone to failure. Furthermore, the arrangement of the valve unit with the associated temperature sensor represents an easy-to-install technology that is not prone to calcification or leaks, and is also essentially maintenance-free.

[0012] According to the invention, the temperature sensor coupled to the valve unit for the hot water priority circuit is assigned to the heating return of the heating circuit. Accordingly, the temperature in the heating return is recorded as a limit temperature, and upon reaching this limit temperature, the heating return of the heating circuit is closed. If the limit temperature is exceeded again, the heating return is also opened again, and regular heating operation resumes, which is unaffected by the withdrawal of a relatively small amount of hot water. The limit temperature is set using a thermostatic valve on the valve unit.

[0013] The subclaims represent advantageous embodiments of the invention.

[0014] Preferably, the tap temperature of the hot water is recorded as the temperature in the heat exchanger for controlling the valve unit. Accordingly, the temperature sensor assigned to the heat exchanger for recording the tap temperature can ensure a specific tap temperature or withdrawal temperature of the hot water. Of course, a corresponding heating water temperature must be present at the heat exchanger to allow the drinking water, also referred to as fresh water, to be heated to the minimum temperature in the heat exchanger.

[0015] Of course, the installed temperature sensors can be connected to the valve unit either via a wire or a wireless interface.

[0016] In one embodiment, the valve unit comprises a first thermostatic valve, at which a temperature of the hot water circuit can be adjusted, and a second thermostatic valve, at which a limit temperature for the hot water priority circuit can be adjusted. Both thermostatic valves are preferably formed in a common valve block of the valve unit.

[0017] It is understood that the features mentioned above and those to be explained below can be used not only in the respective combinations specified, but also in other combinations. The scope of the invention is defined solely by the claims.

[0018] The invention is explained in more detail below using an exemplary embodiment with reference to the accompanying drawing.

[0019] It shows: Fig. 1 a representation of a home station according to the invention, Fig. 2 a schematic representation of the home station according to Fig. 1and Fig. 3 an enlarged view of detail III according to Fig. 2 .

[0020] The apartment station 1 comprises a mounting frame 2 with a mounting plate 3 for attaching all components required for supplying an apartment, particularly in an apartment building, with water and heating water, as well as for distribution. Shut-off valves 4 are provided at the ends of pipes 5 for shut-off. Specifically, a hot water supply 6 and a hot water return 7 are connected to a heat exchanger 8 to provide hot drinking water for the apartment. This hot water can be drawn, for example, from faucets on washbasins, sinks, showers, and bathtubs and is pumped through the hot water circuit by a circulation pump 12.To provide drinking water, a cold water inlet 9 is coupled to the heat exchanger 8, with a water hammer damper 11 inserted into the corresponding pipe 5, which is connected to a cold water outlet 10 leading to the fittings, in order to dampen pressure peaks occurring in the pipe 9 to a certain level. Furthermore, two heating circuits are provided for connecting an underfloor heating system and for connecting radiators, which are to be operated at different temperature levels and each comprise a heating flow 13 and a heating return 14 as well as a circulation pump 17. To supply the apartment station 1 with central thermal energy in a heating water circuit, a heating water flow 15 and a heating water return 16 are provided. Both the heating circuits and the heating water circuit are routed via the heat exchanger 8.A differential pressure regulator 18 and a heat meter 19 are provided between the heating water flow 15 and the heating water return 16.

[0021] For temperature-controlled operation of an underfloor heating system, a temperature-controlled three-way mixing valve 27 is installed between the heating flow 13 and the heating return 14.

[0022] To ensure a specific hot water draw-off temperature, a hot water temperature sensor 21 is assigned to the heat exchanger 8 and coupled to the valve unit 20. The temperature of the hot water circuit, in particular the draw-off temperature, can be adjusted at a first thermostatic valve 22 of the valve unit 20.

[0023] In order to ensure reliable heating by the heating water flowing through the heat exchanger 8 when hot water is drawn off, even in larger quantities, a hot water priority circuit is provided within the apartment station, which comprises a temperature-controlled valve unit 20 with a temperature sensor 23, which is assigned to the heat exchanger 8 in a heating return 14 of the heating circuit for detecting a predetermined temperature, which is also referred to as the limit temperature.

[0024] The limit temperature is set on a second thermostatic valve 24 of the valve unit 20. When the limit temperature is reached, the hot water priority circuit is switched such that the heating return line 14 is closed. The heating water present at the heat exchanger 8 is then fully available for heating the hot water.

[0025] The two temperature sensors 21, 23 are connected by means of conductors 25 to the associated thermostatic valves 22, 24, which are formed or arranged in a common valve block 26 of the valve unit 20.

[0026] To fill the entire system or to enable flushing of the system, or at least the apartment station 1 or the heat exchanger 8, with water, even with water at a relatively high temperature, the second thermostatic valve 24 of the valve unit 20 has a position in which a flow channel in the heating return line 14 is permanently open. This valve position is also referred to as the service position. Reference symbol 1. Home station 15. Heating water flow 2. Mounting frame 16. Heating water return 3. Mounting plate 17. Circulation pump 4. shut-off valve 18. Differential pressure regulator 5. pipeline 19. Heat meter 6. Hot water flow 20. valve unit 7. Hot water return 21. Temperature sensor 8. heat exchanger 22. first thermostatic valve 9. Cold water inlet 23. Hot water temperature sensor 10. Cold water outlet 11. Water hammer arrester 24. second thermostatic valve 12. Circulation pump 25. Director 13. Heating flow 26. valve block 14. Heating return 27. Three-way mixing valve

Claims

1. Method for operating a home station (1) comprising connections for hot water, at least one heating circuit and a heating water circuit which is coupled to a central heat generation device, the heating water flowing through a heat exchanger (8) in order to generate hot water and a hot water priority circuit switching the heating circuit when hot water is drawn by means of a valve unit (20),a return temperature in a heating return (14) being recorded at the heat exchanger (8) and, when a predetermined return temperature is reached at the valve unit (20), the heating return (14) of the heating circuit being closed, characterized in that the return temperature of the heating circuit is recorded for controlling the valve unit (20), and a return temperature causing the opening or closing of the heating return (14) at the valve unit (20) is set at the valve unit (20).

2. Method according to claim 1, characterized in that the tapping temperature of the hot water is recorded as the temperature in the heat exchanger (8) for controlling the valve unit (20).

3. Home station comprising connections for hot water, a heating circuit and a heating water circuit which can be coupled to a central heat generation device, heating water flowing through a heat exchanger (8) in order to generate hot water, and comprising a valve unit (20), a temperature sensor (23), and a hot water priority circuit which switches a heating circuit when hot water is drawn by means of the valve unit (20), the temperature sensor (23) being assigned to the heat exchanger (8), which temperature sensor is coupled to the valve unit (20) such that at a predetermined temperature recorded by the temperature sensor (23), the valve unit (20) closes the heating return (14) of the heating circuit, characterized in that the temperature sensor (23) is assigned to the heating return (14) of the heating circuit.

4. Home station according to claim 3, characterized in that a hot water temperature sensor (21) is assigned to the heat exchanger (8), which hot water temperature sensor is coupled to the valve unit (20).

5. Home station according to either claim 3 or claim 4, characterized in that the temperature sensor (23) and / or the hot water temperature sensor (23) are coupled to the valve unit (20) via a wireless interface or a conductor (25).

6. Home station according to any of claims 3 to 5, characterized in that the valve unit (20) comprises a first thermostat valve (22) at which a temperature of the hot water circuit can be set, and a second thermostat valve (24) at which the temperature in the heating return (14) can be set as a limit temperature for the hot water priority circuit.

7. Home station according to any of claims 3 to 6, characterized in that the thermostat valve (22) and the thermostat valve (24) are arranged in a common valve block (26) of the valve unit (20).

8. Home station according to claim 6, characterized in that the second thermostat valve (24) of the valve unit (20) has a position in which a flow channel in the heating return (14) is permanently open.