Storage system for heating technology

Abstract

Storage system for heating technology, comprising: • a heating water storage tank with an internal potable water coil, which has an inlet for connecting a flow pipe of a heat generator and an outlet for connecting a return pipe of the heat generator, a heating water inlet for connecting a return pipe of a heat distribution system and a heating water outlet for connecting a flow pipe of the heat distribution system, a cold water inlet connected to the potable water coil for connecting a cold water supply and a preheated water outlet connected to the potable water coil, • a potable water storage tank with at least one electric heating element installed therein for heating the preheated potable water from the potable water coil to domestic hot water temperature,which has a preheated water inlet for preheated drinking water and a hot water outlet for connecting a hot water pipe, and • a hydraulic connection between the preheated water outlet of the heating water storage tank and the preheated water inlet of the drinking water storage tank.

Description

[0001] The invention relates to a storage system for heating technology with a heating water storage tank with an internal drinking water coil and a drinking water storage tank for reheating the drinking water.

[0002] Heating water storage tanks with an internal drinking water coil are used to heat and temporarily store heating water and drinking water. The heating water storage tank is a container into which heated water from a heat generator is fed at the top, and from which cooled water is drawn at the bottom and returned to the heat generator. Due to the temperature-dependent density of the water, the temperature of the water in the heating water storage tank decreases from top to bottom, and only minimal mixing of the water occurs.

[0003] For underfloor heating systems and other low-temperature heat distribution systems, heating water flow temperatures in the range of 30°C to 40°C are required. The term "drinking water" refers to domestic water, which includes both drinking water in the true sense of the word for human consumption, as well as water for bathing, showering, and dishwashing. The domestic hot water temperature should be at least 60°C to prevent legionella and other harmful germs from multiplying in the domestic hot water. Significantly higher drinking water temperatures should be avoided to prevent scalding. Therefore, the temperature of the drinking water at the tap should not exceed 60 to 65°C. Heating the heating water to 30°C to 40°C can be achieved using a heat pump. Heat pumps operate particularly efficiently in low temperature ranges and with small temperature differences between the flow and return lines.To achieve a drinking water temperature of at least 60 °C, the drinking water is either additionally heated using an electric heating element in the upper area of ​​the heating water storage tank or the heat pump is temporarily operated so that it supplies heated water at a higher temperature level.

[0004] Due to the low flow temperature of the heating water, the heat pump must provide the required heat output for the distribution system via a high volume flow of heated water. This high volume flow can lead to mixing in the upper section of the heating water storage tank, which reduces the efficiency of heating the heating water and the drinking water. Heating water storage tanks with baffles in the upper section to prevent mixing are already known.

[0005] The invention is based on the object of creating a storage system for heating technology which can be operated more efficiently with a low-temperature heating system and supplies heating water with a flow temperature in the range of 30 °C to 40 °C as well as domestic hot water with a flow temperature in the range of at least 60 °C.

[0006] The object is achieved by a storage system for heating technology according to claim 1. Advantageous embodiments of the storage system are specified in the subclaims and in the following description.

[0007] The storage system for heating technology according to the invention comprises: a heating water storage tank with an internal drinking water coil, which has an inlet for connecting a flow of a heat generator and an outlet for connecting a return of the heat generator, a heating water inlet for connecting a return of a heat distribution system and a heating water outlet for connecting a flow of the heat distribution system, a cold water inlet connected to the drinking water coil for connecting a cold water supply, and a preheating water outlet connected to the drinking water coil, a drinking water storage tank with at least one electric heating element inserted therein for heating the preheated drinking water from the drinking water coil to drinking water temperature,which has a preheating water inlet for preheated drinking water and a domestic hot water outlet for connecting a domestic hot water pipe and a hydraulic connection between the preheating water outlet of the heating water storage tank and the preheating water inlet of the drinking water storage tank.

[0008] The storage system according to the invention comprises, as central elements, a heating water storage tank with an internal drinking water coil and a drinking water storage tank with at least one electric heating element installed therein. The heating water storage tank is a container for storing heated heating water, and the drinking water storage tank is a container for storing heated drinking water. By means of a heat pump or another heat generator, the heating water in the heating water storage tank can be heated to a temperature in the range of 30°C to 40°C. Drinking water flowing through the drinking water coil is preheated in the process. The preheated drinking water enters the drinking water storage tank and is heated there by the electric heating element to the required temperature of at least 60°C. This does not require the heat generator to be temporarily operated at an elevated temperature.Furthermore, efficiency losses due to mixing in the upper area of ​​the heating water tank caused by high volume flows are reduced. Due to the hydraulic separation of the heating water from the heating of the drinking water to domestic hot water temperature, mixing in the heating water tank does not affect the heating of the drinking water, and the latter can be heated more efficiently to domestic hot water temperature. The heat generator can operate continuously at lower temperatures and is therefore more energy-efficient overall. It is also possible to supply the energy requirements of the electric heating element, at least temporarily, with surplus energy from a photovoltaic system.In addition, it is possible to equip the storage system with a smaller drinking water supply than with a conventional storage system because the temperature increase of the preheated drinking water in the drinking water storage tank can be controlled better and faster using the electric heating element than in a conventional heating water storage tank.

[0009] According to one embodiment of the invention, the heating water storage tank is a freestanding unit. This means that the vertical dimensions of the heating water storage tank are larger than its horizontal dimensions, allowing it to be installed in a space-saving manner by utilizing the height of a room. This is also advantageous for creating different temperature zones within the heating water storage tank.

[0010] According to another embodiment, the heating water storage tank is cylindrical, and the drinking water storage tank is cylindrical or spherical. This is advantageous for space-saving arrangement and low heat loss.

[0011] According to another design, the drinking water storage tank is located above or below the heating water storage tank. This is advantageous for a space-saving arrangement and facilitates the design of the storage system as a single unit.

[0012] In another design, the drinking water storage tank is attached to the heating water storage tank. This allows the storage system to be constructed as a single unit. This is advantageous for installation. The hydraulic connection between the heating water storage tank and the drinking water storage tank can be made at the factory. Transporting them separately to the installation site and assembling them at the site can facilitate installation in confined spaces.

[0013] According to another design, the drinking water coil spirals around a vertical axis, with the cold water inlet at the bottom and the preheating water outlet at the top of the heating water storage tank. Due to the higher temperatures in the upper area of ​​the heating water storage tank, this is advantageous for preheating the drinking water. In a design with the drinking water storage tank above the heating water storage tank, the hydraulic connection between the preheating water outlet of the heating water storage tank and the preheating water inlet of the drinking water storage tank can be kept short. The hydraulic connection can be implemented via a pipe or a line. In principle, the preheating water outlet can also be directly connected to the preheating water inlet.

[0014] According to another design, the heating element is arranged horizontally in the drinking water tank. For a drinking water tank with a larger horizontal than vertical dimension, the electric heating element can be designed with a horizontal orientation, providing a particularly large heat transfer surface. This also better ensures that the required domestic hot water temperature is maintained throughout the entire drinking water tank and that the required domestic hot water temperature is reached quickly.

[0015] According to one embodiment, only a single electric heating element is installed in the drinking water storage tank. According to another embodiment, several electric heating elements are installed in the drinking water storage tank. The several electric heating elements can be arranged next to one another and / or one above the other in one or more levels. In particular, several parallel electric heating elements can be arranged next to one another or one above the other in the drinking water storage tank. According to another embodiment, the electric heating element is straight or curved. According to another embodiment, the electric heating element is spiral or helical. The aforementioned designs and arrangements promote the maintenance of the required domestic hot water temperature throughout the drinking water storage tank and the rapid attainment of the domestic hot water temperature.

[0016] According to a further embodiment, a first temperature sensor is arranged in the heating water storage tank and / or in the heating water outlet. A control device is connected to the first temperature sensor and the heat generator and is designed to control the temperature and / or the volume flow of the hot water supplied by the heat generator such that the temperature in the heating water storage tank and / or in the flow of a heat distribution system maintains a specific value or range of values. This is advantageous for controlling the temperature in the heat distribution system.

[0017] According to a further embodiment, a second temperature sensor is arranged in the drinking water storage tank and / or in the domestic hot water outlet. A control device is connected to the second temperature sensor and an electrical power supply of the heating element and is designed to control the electrical power supply such that the temperature in the drinking water storage tank and / or in the domestic hot water supply line maintains a specific value or range of values. This enables particularly good control of the domestic hot water temperature.

[0018] According to another embodiment, the heat distribution system is underfloor heating or another surface heating system. Surface heating systems are preferably used for heating systems with a flow temperature in the range of 30°C to 40°C. However, the heat distribution system can also include large-area radiators or radiators with fan-assisted convection or other suitable systems.

[0019] According to a further embodiment, the heat generator is a heat pump. A heat pump can provide particularly efficient and sustained heated water at a temperature in the range of 30°C to 40°C for heating the heating water and preheating the drinking water. According to another embodiment, the heating system is operated with another low-temperature heat generator, for example, a solar thermal system or a condensing or low-temperature boiler. Hybrid designs comprising several different heat generators of the aforementioned type are also subject to the invention.

[0020] According to another embodiment, the heat pump is an air heat pump and / or a geothermal heat pump.

[0021] According to another embodiment, the electric heating element is powered by electrical power from the power distribution grid. According to another embodiment, the electric heating element is powered by electrical power from a photovoltaic system. According to another embodiment, the electric heating element is powered by electrical power from a power distribution grid and electrical power from a photovoltaic system.

[0022] According to another design, the heating water storage tank has a capacity of 200 to 300 liters, the drinking water coil has a capacity of 25 to 75 liters, and the drinking water storage tank has a capacity of 25 to 75 liters. The storage system with the specified volumes is particularly suitable for a four-person household in a single-family home with current energy standards, using a heat pump as the heat generator and underfloor heating as the heat distribution system. In another design, the heating water storage tank has a capacity of 250 liters, the drinking water coil has a capacity of 50 liters, and the drinking water storage tank has a capacity of 50 liters.

[0023] The attached drawing shows a storage system according to the invention in a rough schematic system diagram.

[0024] The storage system comprises a cylindrical heating water storage tank 1 that is vertically oriented. The heating water storage tank 1 has a cylindrical shell 2, a circular disc-shaped base 3, and a circular disc-shaped cover 4. A drinking water coil 5 is arranged in the heating water storage tank 1, which spirals around a vertical axis. The heating water storage tank 1 has an inlet 6 at the top for heated water from a heat generator in the form of a first pipe socket 7 projecting radially outward from the shell 2, and an outlet 8 at the bottom for connecting a return line for cooled water to the heat generator in the form of a further second pipe socket 9 projecting radially outward from the shell.

[0025] The drinking water coil 5 has a cold water inlet 10 at the bottom in the form of a third pipe socket 11 projecting radially outwards from the casing. At the top, the drinking water coil 5 has a preheating water outlet 12 in the form of a fourth pipe socket 13 projecting radially outwards from the casing.

[0026] The heating water tank 1 has, at the bottom and at the same level as the second pipe socket 9, a heating water inlet 14 in the form of a fifth pipe socket 15 projecting radially outwards from the circumference of the heating water tank 1. At the top, the heating water tank 1 has, at the same level as the first pipe socket 7, a heating water outlet 16 in the form of a sixth pipe socket 17 projecting radially outwards from the casing.

[0027] At the bottom, the heating water tank 1 has a drain nozzle 18 for emptying, which projects radially outwards from the casing and is closed with a first screw cap 19.

[0028] In the upper third, a first insertion nozzle 21, closed with a second screw cap 20, protrudes radially outwards from the casing of the heating water tank 1 for the optional insertion of an additional heating element.

[0029] A cylindrical base 22 with an outwardly projecting flange 23 for placing on a base projects downwards from the bottom 3 of the heating water tank 1.

[0030] A cylindrical drinking water tank 24 is arranged above the heating water tank 1. It has a cylindrical shell 25 and a circular disc-shaped base 26, as well as a circular disc-shaped cover 27.

[0031] The base 26 of the drinking water tank 24 is connected to the cover 4 of the heating water tank 1 via vertical connecting struts 28, for example by welding, soldering or screwing.

[0032] The drinking water storage tank 24 has a preheating water inlet 29 at the bottom in the form of a pipe 30 extending radially from the casing. Within the drinking water storage tank 24, the pipe 30 is curved downward, with its outlet opening 31 aligned with the center of the base 26. Outside the drinking water storage tank 24, the pipe 30 is curved downward and connected to the preheating water outlet 12 of the heating water storage tank 1.

[0033] The drinking water tank 23 has a hot water outlet 32 ​​at the top in the form of a seventh pipe socket 33 projecting radially outward from the casing 25. The hot water outlet 32 ​​is connected within the drinking water tank 24 to a pipe 34 whose inlet opening 35 is aligned with the center of the cover 27 of the drinking water tank 24.

[0034] In the lower third, a second inlet nozzle 36 protrudes radially outward from the casing of the drinking water storage tank 24, into which a heating rod 37 is sealingly inserted. The heating rod 37 is arranged with its heat transfer surface 38 within the drinking water storage tank 24 and has a heating rod section 39 protruding outward from the second inlet nozzle 24, with electrical connections for supplying electrical energy.

[0035] The heating water tank 1 and the drinking water tank 23 have insulation not shown in the figure.

[0036] A heat pump with its flow line 42 is connected to the inlet of the heating water storage tank 1 via a first connecting line 40.

[0037] A return line 45 of the heat pump 41 is connected to the outlet 8 via a second connecting line 43 with an integrated first circulation pump 44.

[0038] A return line 47 of an underfloor heating system 48 or another heat distribution system 49 is connected to the heating water inlet 14 via a third connecting line 46. A flow line 52 of the heat distribution system 48 is connected to the heating water outlet 16 via a fourth connecting line 50 with an integrated second circulation pump 51.

[0039] Warmed hot water circulates through the heating water tank 1 in the heat pump 41, forming a hot water column in the heating water tank 1, with the temperature decreasing from top to bottom. The hot water from the heating water tank 1 circulates through the heat distribution system 49, which transfers the heat to a building.

[0040] In the drinking water coil 5, cold water from a cold water network is preheated and heated in the drinking water storage tank 24 by means of the heating element 37 to a drinking water temperature of at least 60 °C. From there, it flows through a drinking water pipe 33 to the taps.

[0041] The storage system is particularly simple in its construction, space-saving and particularly energy-efficient. List of reference symbols:

[0042] 1Heating water tank 2Shell 3Circular disc-shaped base 4Circular disc-shaped cover 5Drinking water coil 6Inlet 7First pipe socket 8Outlet 9Second pipe socket 10Cold water inlet 11Third pipe socket 12Preheating water outlet 13Fourth pipe socket 14Heating water inlet 15Fifth pipe socket 16Heating water outlet 17Sixth pipe socket 18Drainage socket 19First screw cap 20Second screw cap 21Inlet socket 22Base 23Flange 24Drinking water tank 25Shell 26Circular disc-shaped base 27Circular disc-shaped cover 28Connecting strut 29Preheating water inlet 30Pipe 31Outlet opening 32Domestic hot water outlet 33Seventh Pipe socket 34 Pipe 35 Inlet opening 36 Second inlet socket 37 Heating rod 38 Heat transfer surface 39 Heating rod section 40 First connecting line 41 Heat pump 42 Flow 43 Second connecting line 44 First circulation pump 45 Return 46 Third connecting line 47 Return 48 Underfloor heating 49 Heat distribution system 50 Fourth connecting line51Second circulation pump 52Flow 53Hot water pipe

Claims

1. Storage system for heating technology, comprising: • a heating water storage tank with an internal drinking water coil, which has an inlet for connecting a flow of a heat generator and an outlet for connecting a return of the heat generator, a heating water inlet for connecting a return of a heat distribution system and a heating water outlet for connecting a flow of the heat distribution system, a cold water inlet connected to the drinking water coil for connecting a cold water supply and a preheating water outlet connected to the drinking water coil, • a drinking water storage tank with at least one electric heating element inserted therein for heating the preheated drinking water from the drinking water coil to drinking water temperature,which has a preheating water inlet for preheated drinking water and a domestic hot water outlet for connecting a domestic hot water pipe and • a hydraulic connection between the preheating water outlet of the heating water storage tank and the preheating water inlet of the drinking water storage tank., 2. Storage system according to claim 1, wherein the heating water storage tank is a floor-standing unit.

3. Storage system according to claim 1 or 2, wherein the heating water storage tank is cylindrical and the drinking water storage tank is cylindrical or spherical.

4. Storage system according to one of claims 1 to 3, wherein the drinking water storage tank is arranged above or below the heating water storage tank.

5. Storage system according to one of claims 1 to 4, wherein the drinking water storage tank is attached to the heating water storage tank.

6. Storage system according to one of claims 1 to 5, in which the drinking water coil extends spirally around a vertical axis and the cold water inlet is arranged at the bottom and the preheating water outlet is arranged at the top of the heating water storage tank.

7. Storage system according to one of claims 1 to 6, wherein the heating element is arranged horizontally in the drinking water storage tank.

8. Storage system according to one of claims 1 to 7, in which a first temperature sensor is arranged in the heating water storage tank and / or in the heating water outlet, a control device is connected to the first temperature sensor and the heat generator and is designed to control the temperature and / or the volume flow of the hot water supplied by the heat generator such that the temperature in the heating water storage tank and / or in the flow of a heat distribution system maintains a certain value or value range.

9. Storage system according to one of claims 1 to 8, in which a second temperature sensor is arranged in the drinking water storage tank and / or in the domestic hot water outlet, a control device is connected to the second temperature sensor and an electrical power supply of the heating element and is designed to control the electrical power supply so that the temperature in the drinking water storage tank and / or in the domestic hot water flow maintains a certain value or value range.

10. Storage system according to one of claims 1 to 9, wherein the heat distribution system is an underfloor heating system or other surface heating system.

11. Heating system according to one of claims 1 to 10, wherein the heat generator is a heat pump.

12. Heating system according to claim 11, wherein the heat pump is an air heat pump and / or a geothermal heat pump.

13. Storage system according to one of claims 1 to 12, wherein the electric heating element is operated with electrical power from a power distribution network.

14. Storage system according to one of claims 1 to 13, wherein the electric heating element is operated with electrical current from a photovoltaic system.

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