EP4310411A1 - Method for operating a hot water boiler, computer program, control device, hot water boiler and use of a pressurised gaseous fluid - Google Patents

Abstract

A method is proposed for adjusting a water capacity of a hot water storage tank (1), in which a pressurized gaseous fluid can be supplied to a gas volume (9) of the hot water storage tank (1) and a water volume (13) of the hot water storage tank (1) by increasing or reducing it the gas volume (9) can be adjusted. The gaseous fluid can be supplied through a first valve (5) arranged in the opening (4). This advantageously opens up the possibility of fully automated adjustment of the water capacity of a hot water tank (1), which can bring about a significant increase in user comfort.

Description

The invention relates to a method for operating and in particular for adjusting a water capacity of a hot water storage tank, a computer program, a regulating and control device and the use of a pressurized gaseous fluid.

Systems for providing hot water can have a hot water tank to store the heated water. Particularly when using renewable energies such as solar thermal energy, good conditions for heat generation and a demand for hot water can exist at different times. In order to be able to deliver the amount or temperature of water heated by solar thermal energy as requested by a user, hot water tanks are used to store the heated water until it is used. Depending on the expected scope of use (frequency, quantity, etc.) of the hot water, the water capacity of the hot water storage tank must generally be roughly estimated in advance and then (firmly) selected or installed. A water capacity that is too large can require long periods of time for heating and a water capacity that is too low can result in a low and possibly insufficient maximum amount of hot water being drawn, both of which lead to a loss of comfort.

This is explained in the CN108061379A a hot water tank with adjustable volume is proposed, the tank having a piston and a drive device for movement of the piston in the hot water tank and so a volume of the hot water tank can be adjusted.

The CN204128190U specifies a water tank with several fixed separators within the water tank, each connected to a water outlet. This allows a tank with several adjustable volumes to be created.

The solutions mentioned are complex in terms of production and maintenance. In addition, these are designed to be flexible and/or adaptable to usage requirements only to a limited extent.

Based on this, it is the object of the invention to propose a method for operating a hot water tank, a computer program, a control and control device and a use of a pressurized gaseous fluid, which at least partially overcome the described problems of the prior art. In particular, the method for setting a water capacity of a hot water storage tank should be simple and automated.

These tasks are solved by the features of the independent patent claims. Further advantageous embodiments of the solution proposed here are specified in the independent patent claims. It should be noted that the features listed in the dependent patent claims can be combined with one another in any technologically sensible manner and define further embodiments of the invention. In addition, the features specified in the patent claims are specified and explained in more detail in the description, with further preferred embodiments of the invention being presented.

A method for operating a hot water tank contributes to this, in particular for setting a (current or predeterminable) water capacity of the hot water tank, in which a gas volume (inside) of the hot water tank is changeable by means of a pressurized gaseous fluid and an (adjacent) water volume of the Hot water tank can be adjusted or adjusted by increasing or decreasing the gas volume. In other words, a consumed portion of the water volume of the hot water tank can be compensated at least temporarily by increasing or decreasing the gas volume, or the water volume can be increased, with the gas volume being reduced accordingly.

The hot water tank is a hot water tank for supplying hot water, for example to a building. The hot water tank can be designed as a buffer tank and/or layered tank. It can include a heat exchanger for transmitting a heat flow, for example for heat exchange with a heating circuit of a heating system. The heat exchanger can, for example, be designed as a pipe coil, which (in the assembled or assembled state) can usually be arranged in a (geodetically) lower area of the hot water tank. The hot water storage tank can comprise at least or exactly one volume of water in the interior or the storage space and (if necessary separated from the adjacent water volume by means of a, preferably variably arranged and/or flexible) separating layer) at least or exactly one volume of gas. The water volume corresponds to a predeterminable water capacity of the hot water tank. The gas volume can be adjusted by supplying or removing a gaseous fluid, possibly pressurized (negative or positive pressure), and thus also a water volume of the hot water tank. The gaseous fluid can be supplied and/or removed in a controlled manner and/or at predetermined conditions and times. In particular, the supply and/or removal can take place until a predetermined internal pressure in the hot water tank is set. By supplying and/or discharging the gaseous fluid, the volume fraction of the gas volume can be adjusted or adjusted.

In other words, this means in particular that a consumed or withdrawn portion of the water volume of the hot water tank can or will be compensated for at least temporarily by increasing or decreasing the gas volume. In this way, the (maximum) filling quantity of (cold) water in the hot water tank can be temporarily or permanently adjusted, i.e. limited, for example, if significantly less hot water is or will be called up by the user temporarily or permanently, and/or expanded, if, for example, after such a limitation, a greater need for hot water becomes apparent and needs to be kept available. The set gas volume can in particular limit a spatial and/or pressure-related limitation of the supply of (cold) water to the hot water tank and/or improve the thermal insulation of the stored water or the hot water tank from the environment.

The hot water tank can be set up to hold heated or to be heated drinking water or service water or to hold a heat transfer medium for the heating circuit.

The gaseous fluid can in particular be (ambient) air. Other gases, such as nitrogen, can also be used.

In the hot water tank, part of the gas volume can serve as an expansion area to compensate for volume fluctuations in the water absorbed by the hot water tank caused by temperature-related fluctuations in the density of water. Heating the water contained in the water volume can lead to an increase in its volume.

In order to refill the hot water that has been removed, hot water tanks usually have a cold water supply, i.e. a supply of fresh water, often combined with a domestic water system or a water network. The cold water supply is usually arranged in a lower area of the hot water tank in order to support the formation of temperature stratification in the water volume.

According to one embodiment, a first valve can be arranged in the cold water supply. To reduce the water capacity of the hot water tank, the first valve in the cold water supply can be closed while hot water is being withdrawn from the hot water tank, so that no more cold water can flow in. At the same time, the gas volume can be increased by supplying a gaseous fluid.

At least one (movable and/or deformable) separating element can be provided to divide the water volume and the gas volume.

The separating element can, for example, be arranged floating on the surface of the water volume. In particular, the separating element can be a flat three-dimensional structure. For example, the separating element can have a cylindrical shape with a low height, whereby the base area can largely correspond to the cross-sectional area of the receiving area of water in the hot water tank and thus ensure a largely complete separation from the surface of the water volume and the gas volume. The separating element can have a lower density than water and can therefore be mounted floating on the water volume.

According to another embodiment, the separating element can be an (at least partially) expandable element, for example a rubber bladder, which can form the gas volume when filled with a defined volume of the gaseous fluid. The expandable element can be arranged in particular in an upper region of the hot water tank. Hot water can be withdrawn, for example, through the expandable Element takes place and particularly warm water is taken from the upper area of the water volume due to the temperature stratification. To increase or decrease the gas volume formed by the expandable element, a pressure line can be assigned to it, which can lead through an opening in the wall of the hot water tank. The material of the expandable element should in particular be a material with a low heat capacity.

According to one embodiment, the gaseous fluid can be pressurized by a motor-operated and controllable pump and/or a pressure accumulator. For example, a device similar to a compressor with a pressure accumulator can provide the pressurized gaseous fluid.

According to one embodiment, the gaseous fluid can be supplied through an opening in the hot water tank. A gas valve can be arranged in the opening of the hot water tank.

In particular, the separating element can be a flat three-dimensional structure. Described differently, the separating element can have a cylindrical shape with a low height, whereby the base area can largely correspond to the cross-sectional area of the receiving area and thus ensure a largely full-surface separation of the water surface and the expansion area, and have a lower density than water, and thus floating on the water contained be.

For refilling the gaseous fluid, the hot water tank can have an opening in a wall of the hot water tank, which can be arranged in particular in a geodetically upper region of the hot water tank in the set-up position in order to avoid leakage of the water contained therein.

The at least one (openable and closable) opening can be provided in the area of the gas volume and penetrate the wall of the hot water tank. A pressure-tight and liquid-tight fluid line can be assigned to it.

According to one embodiment, the gaseous fluid can be supplied through an opening in the hot water tank. In particular, the opening can include a second valve. The second valve can in particular be controllable by a motor, so that an automated implementation of a method proposed here is made possible. Alternatively, several openings/second valves can also be provided, for example in such a way that the gaseous fluid can be supplied via an opening/second valve and the gaseous fluid can be removed/drained via a further opening/second valve.

According to one embodiment, a (current) water capacity of the hot water tank can be recorded. For this purpose, for example, a position of the separating element relative to the hot water tank can be recorded. Detection can be carried out, for example, by means of one or more magnetic sensors or one or more Hall sensors, which can be arranged in the area of the wall of the hot water tank. Detecting the water capacity can enable (automated) setting of a predetermined water capacity.

According to one embodiment, the fluid can be stored using a compressed gas container, for example a carbon dioxide or nitrogen container. The compressed gas container can, for example, be arranged interchangeably and be replaced regularly as required. The compressed gas container can also be filled with compressed air and, if necessary, filled with an (external) compressor.

According to one embodiment, in particular in the case of a separating element floating on the water surface, a line element of variable length can be used for removing Water from the hot water tank can be provided. The variable-length line element can (at least partially) penetrate the (variable) gas volume and can therefore bridge different lengths (from the separating element to the opening in the hot water tank). The possibility of changing the length can be created, for example, by a telescopic line element and/or by an elastic or (reversibly) deformable line element. A withdrawal of hot water through the separating element by means of a line element of variable length advantageously enables a withdrawal from an upper region of the water volume, which can have a high temperature when a temperature stratification is formed.

According to one embodiment, the water in the water volume can be heated by means of a heat exchanger, for example a coil, which can generally be arranged in the lower region of the hot water tank or the water volume. The water volume or the water capacity can be adjusted in such a way that it is largely limited to the area/height of the heat exchanger or the pipe coil. This allows the hot water to be heated particularly quickly and thus a high level of user comfort. For example, it is possible to respond to a high demand for hot water, with fully automated implementation being possible by automatically setting a corresponding water capacity.

According to one embodiment, a temperature of the hot water contained in the hot water tank can be recorded. In particular, multiple temperatures can be recorded at different heights of the water volume in order to enable temperature recording of the temperature stratification. Detecting the temperature of the water in the hot water tank can promote automated implementation of a method proposed here.

According to a further aspect, a computer program is also proposed which is set up to (at least partially) carry out a method presented here. In other words, this applies in particular to a computer program (product), comprising instructions which, when the program is executed by a computer, cause it to carry out a method proposed here.

According to a further aspect, a machine-readable storage medium on which the computer program is stored is also proposed. The machine-readable storage medium is usually a computer-readable data carrier.

According to a further aspect, a regulating and control device, for example a heater connected to the hot water tank, is also proposed, set up to carry out a method proposed here. For this purpose, the control and control device can, for example, have and/or have a processor. In this context, the processor can, for example, execute the method stored in a memory (of the control device). Advantageously, operating data and reference values for carrying out a method presented here can also be stored in the memory of the control device. The regulating and control device can in particular have an electrical connection with devices for detecting the water capacity of the hot water tank and/or a water temperature, and can thus carry out a method proposed here fully automatically. An electrical connection refers to a cable or wireless connection for transmitting data.

According to a further aspect, a hot water storage tank is also proposed, having a (variably) adjustable (maximum) water capacity, comprising a gas volume and a water volume, the gas volume being set up to increase its volume by supplying or discharging a pressurized, gaseous fluid change.

According to one embodiment, the hot water tank can comprise a line element of variable length, which is connected or connectable to a separating element floating on a surface of the water volume. In particular, hot water can be withdrawn from an upper region of the water volume of the hot water storage tank via the variable-length line element.

According to one embodiment, the hot water tank can have a regulating and control device proposed here.

According to a further aspect, the use of a gaseous fluid pressurized with (predefined) pressure for the (variable) setting of a (maximum) water capacity of a hot water storage tank is proposed.

The details, features and advantageous configurations discussed in connection with the method can also occur in the computer program presented here, the regulating and control device, the hot water tank and/or the use and vice versa. In this respect, full reference is made to the statements there regarding the more detailed characterization of the features.

As a precaution, it should be noted that the number words used here ("first", "second", ...) primarily serve (only) to distinguish between several similar objects, sizes or processes, i.e. in particular no dependency and/or order of these objects, sizes or prescribe processes to each other. If a dependency and/or sequence is required, this is explicitly stated here or it will be obvious to the person skilled in the art when studying the specifically described embodiment. To the extent that a component can occur multiple times ("at least one"), the description of one of these components can apply equally to all or part of the majority of these components, but this is not mandatory.

Here, a method for setting a water capacity of a hot water tank, a computer program, a regulating and control device, a hot water tank and a use are specified, which at least partially solve the problems described with reference to the prior art. In particular, the method and the hot water tank as well as the use at least contribute to realizing a simple and fully automated possibility for adjusting a water volume of a hot water tank. Advantageously, the ease of use of a hot water tank can be significantly reduced, since the advantages of a large or small water capacity of the hot water tank can be used in a targeted manner. Last but not least, aspects of effective energy use can also be taken into account for setting the water capacity of the hot water storage tank, for example by setting a low water capacity during periods of low hot water demand, and thus heat losses from the hot water storage tank can be reduced, since the heat transfer from the gas volume to the wall of the hot water storage tank is significant is less than the volume of water.

Fig. 1:

einen hier vorgeschlagenen Warmwasserspeicher.

The invention and the technical environment are explained in more detail below using the accompanying figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments given. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and combine them with other components and findings from the present description. In particular, it should be noted that the figures and in particular the proportions shown are only schematic. It shows:

Fig. 1:

a hot water tank suggested here.

Fig. 1 shows an example and schematic of a hot water tank 1 proposed here. This can have a receiving area 2, which is enclosed by a wall 3 becomes. The receiving area 2 can include a gas volume 9 in the upper area (in the set-up position) of the receiving area 2, in which a pressurized gas, in particular air, can be contained. The gas volume 9 can also include an expansion area to compensate for changes in the volume of water absorbed in a water volume 13 due to temperature fluctuations.

The receiving area 2 can separate the gas volume 9 from the water volume 13 by a separating element 11. The separating element 11 can in particular have a density that is lower than the density of water and can therefore float on the water contained or the water volume 13. A temperature sensor 16 for detecting a water temperature of the water volume can be provided in the separating element 11, electrically connected to a regulating and control device 7. The separating element 11 can also be connected to a length-variable line element 12, this being the separating element for removing hot water from the water volume 13 can penetrate. The variable-length line element 12 can bridge different heights of the gas volume 9 with different set water capacities of the hot water tank 1.

The hot water tank 1 can have an opening 4 with a first valve 5 in the wall 3 in the area of the gas volume 9, which can be connected to a pump 6. The pump 6 can pressurize a gaseous fluid, air in the present example, and supply it to the gas volume 9 via the first valve 5 in the opening 4.

The hot water tank 1 can also be connected to a heater 8, for example via a flow 19 and a return 20 of a heating circuit, which can heat the water volume 13 in the hot water tank 1 via a heat exchanger 18, which can in particular be designed as a pipe coil. Hot water can be taken from the hot water tank 1 via a withdrawal tube 10, with the withdrawal tube 10 being over the variable-length line element 12 opens into an upper region of the water volume 13 to take into account temperature stratification in the hot water tank 1 and the associated withdrawal of hot water at the highest possible temperature.

The hot water tank 1 can be connected to a cold water supply 15, for example a cold water connection of a water network. A second valve 14 can be arranged in the cold water supply 15, which can in particular be electrically controllable and can be connected to the regulating and control device 7 for this purpose.

In the wall 3 of the hot water tank 1 there can also be a device 17 for detecting the water capacity, by means of which the set water capacity can be detected based on a position of the separating element 11. The device 17 for detecting the water capacity can be electrically connected to the control and control device 7 and thus enable a fully automated implementation of a method proposed here. For this purpose, the separating element 11 can also have a detection device corresponding to the device 17 in an outer area near the wall 3 or the device 17 arranged there for detecting the water capacity, for example a permanent magnet.

When carrying out a method proposed here, the water volume 13 can be increased by opening the second valve 14 of the cold water supply 15. The water volume 13 can be reduced by no cold water being supplied from the cold water supply 15 when hot water is removed from the hot water tank 1 via the extraction pipe 10 and the variable-length line element 12. For this purpose, the control and control device 7 can keep the second valve 14 closed.

For rapid heating of the water contained in the water volume 13 of the hot water tank 1, the water capacity can also be adjusted in such a way that it is limited (to the height) of the heat exchanger 18 and thus particularly rapid heating can be made possible.

Reference symbol list

1

Hot water tank

2

Recording area

3

wall

4

opening

5

first valve

6

pump

7

Control and control device

8th

heater

9

Gas volume

10

sampling tube

11

Separator

12

length-variable line element

13

water volume

14

second valve

15

Cold water supply

16

Temperature sensor

17

Facility for recording water capacity

18

Heat exchanger

19

leader

20

Rewind

Claims (13)

Method for operating a hot water tank (1), in which a pressurized gaseous fluid can be supplied to a gas volume (9) of the hot water tank (1) and a water volume (13) of the hot water tank (1) by increasing or reducing the gas volume (9) is adjustable. Method according to claim 1, wherein the gaseous fluid is supplied through a first valve (5) arranged in an opening (4) of the hot water tank (1). Method according to one of the preceding claims, wherein water is removed from the hot water tank (1) via a variable-length line element (12) which extends at least partially through the gas volume (9), the variable-length line element (12) being connected to a the water volume (13) floating separating element (11) is immersed in the water volume (13). Method according to one of claims 1 or 2, wherein the gaseous fluid is supplied to an expandable element arranged in the water volume (13), which can increase and decrease the gas volume (9) forming within the water volume (13) to adjust the water capacity. Method according to one of the preceding claims, wherein the water capacity of the hot water tank (1) is recorded. Method according to one of the preceding claims, wherein a controllable second valve (14) is arranged in a cold water supply (15) of the hot water tank (1) and is closed to reduce the water volume (13) during withdrawal. Regulating and control device (7) of a hot water tank (1), set up to carry out a method according to one of claims 1 to 6. Hot water tank (1), comprising a gas volume (9) and a water volume (13), the gas volume (9) being variable by supplying and discharging a pressurized gaseous fluid. Hot water tank (1) according to claim 8, comprising a length-variable line element (12) connected to a separating element (11) floating on a surface of the water volume. Hot water tank (1) according to one of claims 8 or 9, having a regulating and control device (7) according to claim 7. Hot water tank (1) according to claim 10, comprising means adapted to carry out the steps of the method according to any one of claims 1 to 6. Computer program comprising instructions which cause the device of claim 11 to carry out the method steps according to one of claims 1 to 6. Use of a pressurized gaseous fluid to adjust the water capacity of a hot water tank (1).

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