DE102022000076A1 - Arrangement for heating a liquid - Google Patents

Abstract

The invention relates to an arrangement for heating a liquid. An energy unit (1) supplies a heat exchanger (2) with thermal energy. The heat exchanger (2) transfers the thermal energy to the liquid, which is held in a container (3). The container (3) has an opening (21). A pump (20) is connected to the opening (21) of the container (3) and to the heat exchanger (2) in such a way that it pumps liquid out of the opening (21) and/or from the heat exchanger (2).

Description

The present invention relates to an arrangement for heating a liquid. In addition, the arrangement is used to heat a gas, e.g. B. room air. The liquid is, for example, process water.

In the prior art it is known to gain thermal energy from the combustion of, for example, propane, butane or diesel fuel converted into the gaseous state, or by using electric power, and to transfer it via a heat exchanger (or: heat exchanger) to a liquid, e.g. B. to transfer domestic water. It is also known that such devices serve as a supplement as air heaters.

Normally devices for heating a liquid are operated in the manner of a water heater or a boiler. So either the heated water is output directly after passing through a heating section. Or water is heated in a container so that the user can remove it when needed. From the user's point of view, an instantaneous water heater is very convenient. In order to provide a large amount of warm water, however, a correspondingly high heating capacity is required. If a lower heat output is sufficient, a buffer storage tank - as with a boiler - is required for the warm water. However, the disadvantage of such buffer storage (or liquid containers) is that the heat source is usually installed below, so that the heating destroys a temperature stratification in the storage buffer. Furthermore, a significant proportion of the total volume must be heated before water of the desired temperature is available.

The invention is based on the object of proposing a way of providing heated liquid which departs from the known principles of flow heaters and boilers, and which therefore represents an alternative to the prior art. The possibility should preferably be distinguished by the fact that the disadvantages of a boiler are also avoided in the event that only a low heating capacity is available and is not sufficient for operation as a continuous-flow heater.

The invention solves the problem with an arrangement for heating a liquid, with an energy unit, a heat exchanger, a container and a pump, the energy unit supplying the heat exchanger with thermal energy, the heat exchanger transferring the thermal energy to the liquid, the container receives the liquid, the container having an opening, and the pump being connected to the opening of the container and to the heat exchanger in such a way that the pump delivers liquid from the opening and/or from the heat exchanger.

According to the invention, there is an arrangement which represents a combination of a flow heater and a boiler. A pump conveys liquid either in front of the heat exchanger (this would be the flow heater) or from a container for the liquid (this would be the boiler). If more liquid leaves the heat exchanger than is discharged from the pump, e.g. B. in the direction of a fitting as a dispensing point, is promoted, liquid passes through the opening into the container. If the pump conveys more liquid, it takes liquid from the container via the opening. If the pump conveys as much liquid as leaves the heat exchanger as heated liquid, the opening of the container and the container itself are thus bridged. The pump thus conveys in particular heated water away from the heat exchanger.

In the following, two teachings are discussed, which relate to particular configurations of the container: one with two openings, whereby the liquid can leave the container through one opening, and one with a variable volume of liquid. Both teachings can be applied to the aforementioned invention. The same applies to the configurations discussed below.

According to one embodiment, a further pump is present, with the further pump conveying liquid to be heated through the heat exchanger, and with the opening of the container being arranged between the heat exchanger and the pump. In one of the following configurations, the additional pump is referred to as a cold water pump. The other pump conveys the liquid through the heat exchanger, which heats it up. The flow rates of the pump and the additional pump are therefore decisive as to whether liquid gets into the container or is removed from it.

One embodiment provides that a temperature sensor is present for measuring a temperature of the liquid heated by the heat exchanger, and that a control device receives measured values from the temperature sensor and uses them to control the additional pump. In this embodiment, the temperature of the heated water is controlled.

One embodiment includes that the pump conveys heated liquid to a mixing section, with a cold water path being present which opens onto the mixing section, with a mixing temperature sensor for measuring a temperature of the liquid is present in the mixing section, and wherein a control device controls the pump and/or a cold water path pump for conveying the liquid in the cold water path based on measured values of the mixing temperature sensor and a predetermined temperature range. In this embodiment, the heated liquid is cooled to a predetermined temperature range. This is, for example, anti-scalding protection. For this purpose, the heated liquid is mixed with cold or unheated liquid in a mixing section. Based on the temperature of the liquid in this mixing section, at least one pump is regulated in terms of its delivery rate: This is either the pump that delivers the heated liquid or a cold water path pump that delivers the unheated liquid.

One embodiment provides that a ventilation/venting valve is present, with the ventilation/venting valve allowing air to be discharged from the arrangement, with a ventilation pump for discharging air and liquid through a return line being present, and with the return line upstream of the Ventilation valve and opens before the other pump. In this embodiment, air is removed from the heated liquid via a ventilation/venting valve, which in this context can be implemented as a pure venting valve. Furthermore, the ventilation valve is followed by a ventilation pump, which pumps air (or gas in general) and liquid into a return line. So that the air is discharged and can thus z. B. not get to the fitting. As the discharged liquid is already heated, it is introduced in front of the suction area of the further pump. The liquid is then pumped back through the heat exchanger and the thermal energy is not lost. The air in this liquid also reaches the ventilation valve again through the heat exchanger.

A further embodiment consists in that there is a component between the ventilation valve and the ventilation pump, which opens when a predetermined pressure difference is exceeded, so that the liquid can flow in the direction of the ventilation pump. There must therefore be a sufficient pressure difference between the two sides of the component. This pressure difference can also lead to air being released.

A supplementary embodiment provides that the ventilation valve is not only used for ventilation, but also allows air to penetrate into the line system of the arrangement. In this case, it is provided that the additional pump pumps air through the heat exchanger in one conveying direction and liquid through the heat exchanger in another conveying direction. The air penetrating from the outside via the ventilation valve, which in one embodiment consists of two separate units: one for ventilation and one for ventilation, serves to empty the heat exchanger.

One embodiment provides that a decalcifying device is present, the decalcifying device being arranged along the return line in such a way that it adds a decalcifying agent to the liquid conveyed by the venting pump. In this embodiment, a decalcifying agent is added to the returned liquid.

According to a first teaching, it is provided that there is an arrangement for heating a liquid, with an energy unit, a heat exchanger and a container, the energy unit supplying the heat exchanger with thermal energy, the heat exchanger transferring the thermal energy to the liquid, the Container that receives the liquid, wherein the container has at least two openings, and wherein there is a height difference between the two openings, so that a hydrostatic pressure difference is established.

The arrangement according to the invention comprises at least one energy unit, a heat exchanger and a container. The heat exchanger transfers the energy from the unit - z. B. by applying the electric current or by burning a fuel-air mixture - generated thermal energy on the liquid so that it is heated.

The container holds the liquid. It has two openings at different heights, so that there is a hydrostatic pressure difference between the two openings. One opening is thus higher in the direction of the earth's gravitational field than the other opening. This is accompanied by the fact that the liquid that is let in via the upper opening displaces the liquid already present in the container through the lower opening. This allows, for example, the container to be slowly filled with heated liquid via the upper opening, with the colder liquid flowing out through the lower opening due to the temperature-related density difference of the liquids. Conversely, it is possible, for example, to remove liquid via the upper opening, which can lead to automatic refilling via the lower opening. By filling and removing the liquid through an opening, the opposite process (i.e. emptying or filling) can be triggered.

Accordingly, the arrangement is in operation during use in such a way that both openings of the container are open, ie allow the passage of liquid. In particular, one - the upper - opening z. B. via hoses or pipes - connected to the other components. Preferably the other opening - e.g. B. also via at least one hose or pipe - connected to a cold water tank (z. B. a fresh water tank of a vehicle or caravan).

The container can thus be viewed with its openings as a type of hose (or tube) that has a larger capacity. The connection to the surrounding components (that is, pumps or normal liquid/air lines, etc.) is such that liquid is introduced into or removed from this container hose in both directions of flow. The imaginary tube is arranged in the gravitational field in such a way that one opening to this larger absorption volume is located above the other opening.

If the container is connected to atmospheric pressure via at least one opening, this has the advantage that no safety valve is required, as is the case with a pressurized container according to the prior art. In the arrangement, for example, the lower opening is connected to a tank which is open and thus at atmospheric pressure. In use, care should preferably be taken to ensure that the lower opening is connected to the tank via a hose or pipe and that this hose or pipe ends below the liquid surface of the tank. The end of the hose should therefore be submerged. This makes it possible to prevent the container from being emptied or being infiltrated by air from below, even if it is arranged above the tank.

Due to the nature and arrangement of the container and the way the container is used, there is no air pocket in the container. In normal operation, the container is thus completely filled with liquid. Since there is no air bubble in the container, its volume can accordingly be used completely for the provision of heated liquid, so that a small total volume is also possible as a result. If the liquid undergoes thermal expansion, this additional volume is discharged through the lower opening into the listed components, for example a fresh water tank. Compensation components, such as expansion tanks equipped with gas cushions, are therefore not required.

By draining the liquid from one opening of the container while filling takes place via the other opening, there is the advantage that z. B. the energy unit can be operated continuously. The thermal energy is continuously dissipated via the heat exchanger and the liquid, even if the liquid in the container is already fully heated. Therefore, the energy unit has to be started and switched off less frequently, e.g. B. the energy consumption when starting or the risk of a generally disadvantageous starting process can be avoided. It is omitted e.g. B. also a waiting time that may be required before a new start of the energy unit is possible. There are e.g. B. less flushing of the combustion chamber necessary to prepare the energy unit. This is a clear advantage, for example, when the energy unit z. B. burns a fuel such as diesel fuel to generate the thermal energy. It is also particularly advantageous to be able to operate the burner for a certain minimum burning time, even if the container is already completely filled with heated liquid. This reduction or avoidance of numerous start/stop processes of the energy unit that involve waiting times enables high hot water availability with a significantly smaller tank volume.

In one variant, the energy unit, the heat exchanger and the container belong to a heating device, which is used to heat the liquid and which is connected to other components to form an overall arrangement (alternative designation is system). The arrangement would then be the device plus other components in the periphery around the device. In one embodiment, the device therefore has corresponding interfaces in order to connect to the other components. In one embodiment, a further component is, for example, an additional container, which expands the capacity of the container. From a functional point of view, the combination of container and additional container can be viewed as a unit.

A control device is preferably additionally present, in which setpoint specifications are or can be stored, to which measured values are sent and which, based on the setpoint specifications and the measured values, controls components of the heating device and/or the arrangement. Control is generally understood as an intervention in another unit with regard to its settings or its mode of operation. Controlling is therefore used to specify what this unit does and to what extent. The term control can therefore include both control in the narrower sense and regulation.

According to a second teaching, it is provided that the arrangement for heating a liquid is provided with an energy unit, a heat exchanger, a container and a control device, with the energy unit supplying the heat exchanger with thermal energy, with the heat exchanger transferring the thermal energy to the liquid, wherein the container holds the liquid, wherein the container has an opening, and wherein the container has a variable volume of liquid. In this alternative teaching of the invention, the container preferably has only a single opening into which the liquid is introduced or from which the liquid is removed, and which is connected to other components of the arrangement. Such an opening is to be separated, for example, from a passage through which the liquid can pass from the actual container to an additional container or additional tank. Such an additional tank only increases the internal volume of the overall container arrangement made up of container and additional tank. In addition, the container has a variable liquid volume. The container can thus expand or contract according to a type of bubble, so that the amount of liquid that can be absorbed can lie between a minimum and a maximum value.

In one embodiment, the container is supplemented by an additional container or additional tank. The combination of container and additional tank has a total of only one opening to the other components of the arrangement or the periphery around the arrangement. There may be openings between the reservoir and the auxiliary tank, but the liquid only flows through them within the combination of the two.

What the two teachings according to the invention have in common is that the containers are used in such a way that only the liquid and no air are in them. This is done either - in the case of the first teaching - through the two openings in the container through which the liquid passes, or - in the case of the second teaching - through the variable possibility of the container to accommodate different amounts of liquid.

According to one embodiment of the second teaching of the invention, it is provided that the arrangement is designed according to one of the variants mentioned above or described below. The configurations also apply correspondingly to the arrangement according to the first teaching.

According to the above second teaching, the container has only one opening, but has a variable volume of liquid. As for the container with two openings, some of the following configurations also apply to this container, which has a variable volume of liquid, for example.

According to one embodiment, the container is made at least partially from a plastic. The use of plastic is possible because the container - apart from the usually negligible hydrostatic pressure - does not have to withstand any internal pressure. The material used is characterized by its low weight and almost any shape design option. Furthermore, the execution is usually inexpensive. A plastic or a kind of plastic is also used in the variable liquid volume container, for example.

• • Im Zusammenhang mit der - im Folgenden besprochenen - Ausgestaltung des Verbrühschutzes beispielsweise durch die Steuerung der Heißwasserpumpe bzw. der Kaltwasserpfad-Pumpe ist es möglich, Flüssigkeit mit einer hohen Temperatur im Behälter zu speichern.
• • Wenn die dem Wärmeübertrager konstant zugeführte Energie über eine konstant hohe Temperaturdifferenz der durch ihn geförderten Flüssigkeit abgeführt wird, so gibt es einen gleichbleibend kleinen Volumenstrom an erwärmter Flüssigkeit in den Behälter hinein. Eine solche kleine Strömungsgeschwindigkeit sorgt dafür, dass eine Temperaturschichtung im Behälter kaum gestört wird.
• • Da der Behälter - mit den zwei Öffnungen gemäß der ersten Lehre - über eine Öffnung im Druckausgleich mit der Atmosphäre steht und sich somit z. B. bei Erwärmung der Flüssigkeit kein innerer Überdruck in ihm aufbauen kann, ist keine Gasblase zur Druckbegrenzung erforderlich.
• • Wenn keine Luftblase vorhanden ist, verbessert dies die Schichtung, weil Verwirbelungen vermieden werden.
• • Das Behältervolumen bemisst sich nur an den Erfordernissen des Warmwasserbedarfs und muss kein zusätzliches Volumen beinhalten, um den Ansprüchen in Bezug auf eine Feuerung in der Energieeinheit als Wärmesenke (z. B. wegen Mindestlaufzeiten oder Wartezeiten) gerecht zu werden.

One embodiment provides that the container has the smallest possible volume. This reduction is possible because a large amount of heated liquid does not have to be stored, but a requirement for heated liquid that goes beyond the volume of the container is covered directly by the heating of additional liquid by the heat exchanger. Reasons for a small container volume are, for example, the following:

• • In connection with the configuration of the anti-scald protection - discussed below - for example by controlling the hot water pump or the cold water path pump, it is possible to store liquid at a high temperature in the container.
• • If the energy constantly supplied to the heat exchanger is dissipated via a constantly high temperature difference of the liquid conveyed through it, then there is a constantly small volume flow of heated liquid into the container. Such a low flow speed ensures that temperature stratification in the container is hardly disturbed.
• • Since the container - with the two openings according to the first lesson - is an opening in pressure equalization with the atmosphere and thus z. B. when the liquid is heated, no internal overpressure can build up in it, no gas bubble is required to limit the pressure.
• • The absence of an air bubble improves stratification because turbulence is avoided.
• • The volume of the tank is only based on the requirements of the hot water requirement and does not have to contain any additional volume in order to meet the requirements in relation to firing in the energy unit as a heat sink (e.g. due to minimum terms or waiting times).

According to one embodiment, the container is designed in such a way that an essentially complete emptying with regard to the liquid is possible. This is for reasons of hygiene, among other things. So there remains no liquid in which z. B. form germs after a long period of non-use. Residual emptying is also advantageous if decalcification or other chemical cleaning of the arrangement is to be carried out.

According to one embodiment, the container is connected or can be connected to a fresh water tank via an opening. The fresh water tank belongs, for example, to a vehicle, a caravan or mobile home or a boat in which the arrangement is installed as a system. The liquid, ie the water, which is to be heated is preferably removed from the fresh water tank. If the opening of the container is connected to the fresh water tank, through which the liquid leaves the container - heated at least during the operation of the system - active heating of the fresh water tank is possible and the risk of frost for the fresh water tank can be counteracted.

One configuration consists in that the heat exchanger is assigned a pump for conveying the liquid through the heat exchanger, with a temperature sensor for measuring a temperature of the liquid conveyed through the heat exchanger being present, and with the control device receiving measured values from the temperature sensor and for controlling the pump used. In this embodiment, regulation takes place so that the heated liquid has a predetermined setpoint temperature. To do this, the temperature of the liquid behind the heat exchanger is measured. Based on this actual value, the pump is then controlled so that the amount of liquid pumped is adjusted. In one of the following configurations, this pump is, for example, a cold water pump that is connected to a cold water tank, e.g. B. an on-board fresh water tank. Controlling the temperature of the heated liquid has the advantage that the volume of the container can be optimally used to store liquid at a consistently high temperature, regardless of the temperature of the cold liquid or the thermal energy supplied to the heat exchanger, i.e. the degree of heating that the heat exchanger can achieve based on this energy supply.

One embodiment consists in that a pump is present, that the pump is connected to one of the two openings of the container and to the heat exchanger, and that in the event that the pump takes liquid from the container via one opening, liquid via the other opening flows into the container. In this embodiment, there is a pump which can convey the liquid from the heat exchanger and/or from an opening in the container. It thus moves liquid heated by the heat exchanger and/or liquid that is in the container, for example in the direction of a fitting, via which the liquid can be removed from the system. If the liquid is now removed from the container via one of the two openings, liquid is refilled via the other of the two openings, preferably to the same extent. The container is thus not emptied, but it remains filled. In one embodiment, the liquid that flows in via the other opening is cold liquid and in particular not a liquid that has been heated by the heat exchanger. In one embodiment, the opening through which the pump removes the liquid from the container is the upper opening.

In one embodiment, in particular for the arrangement according to the second teaching with the variable liquid volume, it is provided that a pump is present, that the pump is connected to the opening of the container and to the heat exchanger, and that in the event that the pump is connected via the Opening the container removes liquid, the volume of liquid in the container decreases. The container thus contracts, for example, when liquid is removed from it.

In one of the following configurations, the pump for conveying the liquid from the heat exchanger and the container is referred to as a hot water pump, for example.

In one embodiment, a pump takes heated liquid from the container or pumps liquid that has been directly heated by the heat exchanger. If, in this embodiment, heated liquid is removed from the container over a period of time such that there is no longer any heated liquid in it, i.e. its usable heat capacity is exhausted, the pump (for example the hot water pump according to one embodiment) primarily draws liquid directly from the heat exchanger promoted and thus reaches the outflow of the arrangement, ie z. B. to a fitting. Therefore, the function of the continuous-flow heater helps in this case, so that in particular there is no sudden jump from temperature-controlled to cold liquid, as is possible with boilers.

According to one embodiment, it is provided that a ventilation/venting valve is present and that the ventilation/venting valve enables air to be supplied into the arrangement or gas to be discharged from the arrangement, depending on the application. In this component, gas (eg air) is discharged from the arrangement via a valve or a valve arrangement, or air (in particular ambient air from the area around the arrangement) is supplied. The removal of air also refers to gas that is released from the liquid when it is heated - for example due to reduced solubility. The supply of air allows at least parts of the arrangement to be emptied or deflated.

In one embodiment, the ventilation valve is a single component that performs the dual function. In an alternative embodiment, there are two separate components that are considered as one functional unit.

One embodiment provides that there is a ventilation valve, that there is a ventilation pump for removing gas and liquid, and that a return line is arranged in such a way that it opens in front of the ventilation valve and in front of a pump that Liquid promotes through the heat exchanger. When the liquid is heated, gases or z. B. escape air that are dissolved in the liquid. A ventilation valve is provided to prevent this air from getting to a fitting or to prevent the air from getting into the container. The ventilation valve is preferably connected to the line in which the liquid heated by the heat exchanger is conducted. There is also a bleed pump that can drain air and liquid. In one embodiment, the venting pump is arranged downstream of the ventilation/venting valve. Liquid that has already passed through the ventilation valve is thus also discharged by the ventilation pump. The liquid and thus also the air is guided through a return line, which opens in front of a pump and in front of the ventilation valve. The pump conveys liquid through the heat exchanger. This returned liquid thus again passes the ventilation/venting valve in order to discharge further air, if necessary. So that the venting effect is increased. Correspondingly, only the venting character is relevant for the ventilation/venting valve in the embodiment, so that the ventilation/venting valve can be reduced in particular to a pure venting valve in one embodiment. Furthermore, the recirculated liquid is passed through the heat exchanger again in order to take the same route as the liquid to be heated and not recirculated. The thermal energy that has already been transferred is therefore not lost, but is transferred to the liquid to be heated.

In one embodiment, the venting pump is also connected to an opening of the container, so that venting of the container is possible here.

In one embodiment, the function of the ventilation/venting valve is divided between two separate valves: one valve is used for venting, so that air escaping from the heated liquid is discharged from the arrangement. Another valve is used for ventilation in order to empty the heat exchanger through the air from the environment. Alternatively, a valve - as already mentioned above - fulfills both functions.

In one embodiment, the venting pump is not operated continuously, but rather intermittently. Investigations have shown that the pump's operation interrupted by pauses can increase the amount of air that can be discharged without the amount of liquid discharged during pumping increasing to the same extent. Significantly more gas can therefore be discharged.

According to a further embodiment, the return line opens out relative to a feed line of a pump, which conveys liquid to be heated to the heat exchanger. The orifice area and the effective pump performance of the venting pump and the pump are matched to one another in such a way that the recirculated liquid is essentially pumped more strongly by said pump in the direction of the heat exchanger than the venting pump brings the liquid into the supply line. In other words: The venting pump brings the returned liquid only so far in the return line to the feed line that the addressed pump takes over the further promotion. In one embodiment, the venting pump is designed in such a way that it delivers more, at least for a short time (this is associated with intermittent operation of the pump), than the pump for delivering the liquid to be heated. Due to the intermittent operation, the returned liquid does not reach one end of the feed line into which the venting pump delivers liquid and gas or air, but only in this direction. In this way, a “reservoir” of heated liquid is advantageously created, from which the pump takes liquid again when conveying the liquid to be heated. This option for the pump is based on the fact that the return line ends in front of the cold water pump. The short-term high pumping capacity of the vent pump is, as studies have shown, advantageous to the entrain gas bubbles. In one of the following configurations, the pump for conveying the liquid to be heated is referred to as a cold water pump.

In one embodiment, there is a component between the ventilation valve and the ventilation pump, which only opens when a predetermined pressure difference is exceeded, so that the liquid can flow in one direction. The direction of flow is away from the heat exchanger or towards the container. The component only allows the liquid to flow in one direction if there is a certain pressure difference. This component ensures that the tank does not fill with air via the ventilation valve due to the hydrostatic underpressure caused by its height and arrangement, and that the heated water escapes through the bottom end of the tank. This also applies in particular to an embodiment in which the container is arranged above the cold water tank. The pressure drop in the liquid caused by the flow through this component causes more gas to escape from the liquid, which can be discharged via the vent pump.

One embodiment provides that air can also be introduced into the arrangement via a component, which is preferably the ventilation valve, and that a pump (this is the cold water pump in one embodiment, for example) is present, which is introduced via this component Promotes air through the heat exchanger. This configuration—preferably in conjunction with the component mentioned above, which only opens when there is a pressure difference—allows the heat exchanger to be emptied without simultaneously emptying the container. This is relevant, for example, if the heat exchanger also transports air, e.g. B. to heat room air. In this case, emptying can prevent liquid from being heated and evaporating in the heat exchanger while the air is being heated. The air introduced is in particular ambient air from the space outside the arrangement. In one embodiment, the pump is operated until the heat exchanger has been emptied.

The aforementioned component for introducing the air is implemented as follows, for example: It is a sphere with a lower density than the heated liquid, e.g. B. water, present, which is pressed by the liquid up on a seal. As a result, the ball (or a suitably shaped float) closes an opening within the seal to the atmosphere. If there is no liquid under the sphere, because it is being pumped out in particular, the sphere falls down due to gravity and the opening is no longer closed. Therefore, air can flow in.

In one embodiment, the pump conveys the air through the heat exchanger in one direction and the liquid through the heat exchanger in another direction. In this embodiment, a pump (for example the cold water pump) is provided, which can deliver two different media (liquid and air) in two different directions. Alternatively, there is a pump for each medium and for each direction.

One embodiment provides that a pump conveys the heated liquid to a mixing section, that there is a cold water path that opens into the mixing section, and that a mixing temperature sensor is present for measuring a temperature of the liquid in the mixing section. In this configuration, the temperature of the heated liquid, which has therefore been heated by the passage through the heat exchanger, is reduced to a predeterminable mixed temperature. To do this, the heated liquid is mixed with cold, i.e. unheated, liquid in a mixing section. A temperature sensor is available for setting the temperature of the liquid in the mixing section. Controlling the temperature (e.g. by adjusting the flow rate of at least one pump that transports the heated/hot or cold liquid to the mixing section) in the mixing section means that liquid with a constant temperature, e.g. B. is issued at the fitting. In one embodiment, both the temperature of the heated liquid (e.g. via the control of the cold water pump) and the temperature of the mixed temperature are controlled. In one of the described configurations, the pump that conveys the heated liquid is referred to as a hot water pump. In one embodiment, tempering the liquid in the mixing section allows the liquid in the heat exchanger to initially be heated to a sufficiently high temperature, e.g. B. to kill germs, is heated and that there is still no scalding z. B. on a faucet or a shower head. For this protection against scalding, electronic components that serve to regulate the mixing are designed redundantly in one embodiment to increase the level of safety. As already mentioned, the regulation of the temperature of the heated liquid also has the advantage that the volume of the container can be optimally used to store liquid at a consistently high temperature - this is independent of the temperature of the cold liquid or that fed to the heat exchanger thermal energy.

In one embodiment, both the quantity of the heated liquid that is conveyed to the mixing section and the quantity of cold liquid that is conveyed that reaches the mixing section are regulated. The cold liquid, which originates from the cold water tank, for example, from which the liquid to be heated is taken, is conveyed in one embodiment by a cold water path pump. In one embodiment, the latter pump is also the vehicle pump of the vehicle in which the arrangement is installed.

In one embodiment, it is provided that the control device controls the pump and/or a cold water path pump for conveying the liquid in the cold water path based on measured values of the mixing temperature sensor in such a way that the temperature of the liquid in the mixing section changes at different pressure conditions in the mixing section and/or or in the area of the pump or the cold water path pump and/or with different flow rates of the liquid in the mixing section and/or in the area of the pump or the cold water path pump is essentially within a predetermined temperature range. Throughout the description, the control of a pump preferably refers to its flow rate. The temperature range is preferably a tolerance range around a setpoint. In other words: The temperature sensor, which measures the temperature of the liquid in the mixing section, allows the temperature of the liquid to be regulated. B. is issued as a warm liquid or specifically as warm water through a faucet. The temperature is kept essentially constant and this is preferably independent of pressure conditions and preferably also independent of flow rates that occur in the arrangement. In one embodiment, the flow rate relates to the flow rate in the mixing section and therefore also to the amount that is removed from the arrangement via a fitting.

In one embodiment, the pump, which delivers the heated liquid to the mixing section, is then activated when a removal of warm liquid z. B. takes place on a fitting. In one embodiment, this activation can take place via electrical contacts on the withdrawal fitting. In an alternative embodiment, the removal of a falling system pressure z. B. detected by a pressure switch. In both variants, the signal for removing warm liquid can also be used to control a pump (this is, for example, the cold water pump) for conveying cold liquid or liquid to be heated.

According to one embodiment, two pumps convey liquid to a mixing section, with the two pumps being active at the same time. Preferably, one pump delivers heated liquid and the other pump delivers cold liquid to the mixing section. It is provided that usually or always both pumps are active. This prevents, for example, only cold or only heated liquid from reaching a fitting. In one embodiment, the two pumps are the hot water pump and the cold water path pump.

One aspect is that there is a component for introducing air into the assembly and there is a pump that introduces air introduced via the component into the container through one of the two openings so that the liquid enters the container through the other opening leaves. This configuration allows the liquid container to be emptied or aerated.

In the embodiment, air is introduced into the container for emptying. The component for introducing the air z. B. room air from the environment around the arrangement or in particular around the liquid system, functions in one embodiment as an overflow valve. In one of the configurations described, the component is referred to as a branching check valve, for example. The component preferably allows a fluid (here the air) to flow in only one direction (namely in) and preferably only above a certain pressure difference. The required minimum pressure difference prevents the container from being automatically emptied due to the hydrostatic vacuum created by the two openings at different heights, in that air flows into the container via the aforementioned component for introducing air. Only the pump described, which in one embodiment runs backwards for this purpose, ensures the required pressure difference. In one embodiment, this pump is the hot water pump.

In one embodiment, the air is introduced into the container preferably via the opening through which heated liquid is introduced into the container. In one embodiment, heated liquid and air are introduced into the container via an opening and heated liquid is removed in different operating states. If air enters the container through one opening, the liquid flows out of the container through the other opening.

In a supplementary embodiment, the pump is the one that conveys the heated liquid away from the heat exchanger or out of the container. For example, this is the hot water pump.

According to one embodiment, there is a pump which is connected to one of the two openings of the container and to the heat exchanger in such a way that the pump delivers liquid from the opening and from the heat exchanger. In the appropriate configuration for the second teaching, the pump is connected to the opening of the container and to the heat exchanger, so that the pump delivers liquid from the opening and from the heat exchanger.

In a further development, the pump is connected to a hose or tube, which opens out onto the opening and onto the heat exchanger. Thus, if the pump pumps liquid out of this hose or pipe, then liquid from the container and/or out of the heat exchanger reaches the pump and thus the part of the arrangement which is connected to the pump. If a corresponding amount of liquid is heated by the heat exchanger, the function of a flow heater can be mapped. If this amount of liquid from the heat exchanger is not sufficient to meet current requirements, liquid is additionally or alternatively taken from the container. In this case, the function of a boiler results. Due to the direct connection between the pump - which can also be referred to as a hot water pump in one embodiment - and the heat exchanger and the associated flow heater function, it is possible to remove heated liquid with a start of heating. The heating is the process whereby the heat exchanger receives thermal energy from the energy unit.

In one embodiment, the two previous embodiments are combined in that only one pump is used for both purposes. According to the embodiment, it is provided that the pump conveys the liquid out of the container opening and from the heat exchanger in one conveying direction and the air into the container in another conveying direction. This one pump thus conveys air and liquid in two different directions. In one direction it promotes heated liquid z. B. to a fitting. In the other direction, it conveys air to the container and thereby empties it.

One configuration consists in that two pumps are present, that one pump of the two pumps conveys liquid to be heated to the heat exchanger, and that the other pump of the two pumps is located downstream of the heat exchanger and conveys air and liquid. In this embodiment, there are two pumps, one upstream and one downstream of the heat exchanger. The pumps thus convey liquid to be heated (or cold) or heated (or hot). In one embodiment, the upstream pump is referred to as a cold water pump. In one embodiment, the first-mentioned pump, which in one variant is located upstream of the heat exchanger, is designed in such a way that it can convey air and liquid. The downstream pump is designed in such a way that it not only conveys liquid but also air. This air is the air that escapes from the liquid during the heating of the liquid. The downstream pump thus allows the line behind the heat exchanger to be vented. In one embodiment, the downstream pump is designed as a venting pump. In an alternative embodiment, it is the hot water pump.

A more extensive embodiment provides that the other—that is, downstream—pump conveys air and liquid intermittently. This pump--which is preferably the aforementioned venting pump--is therefore not operated continuously, but only at certain time intervals of a definable duration and at definable time intervals. This is in contrast to the upstream pump (e.g. the cold water pump), which runs continuously during operation, i.e. during the heating phase of the liquid.

According to one embodiment, the container has a variable internal volume. In this embodiment, the container is not a rigid component with a fixed internal volume, but its internal volume can be changed. For example, the container is configured as a bladder around which a support structure, e.g. B. is a grid. The variable internal volume is implemented not only in the container with one opening for the arrangement according to the first teaching, but in one embodiment also in the container with two openings for the arrangement according to the first teaching.

In one embodiment, there are two pumps, one pump pumping the liquid through the heat exchanger and the other pump pumping the liquid from the heat exchanger and the liquid from the container, e.g. B. conveyed towards a fitting, and wherein an opening of the container is arranged between the two pumps. The arrangement of the connection points of both pumps (one behind the other) and the arrangement of the container opening (in between) ensures that the container automatically compensates for the difference in the two pump delivery rates. If the upstream pump conveys more than the downstream pump, the heated liquid enters the container through the opening between the two pumps. Promotes in the other case, the downstream pump more liquid than the upstream pump delivers, so the container through the Publ removed from the heated liquid. This also clearly shows the dual function of the upper opening of the container as access to and exit from the container. In view of the first teaching, the opening of the container is either the opening which is located higher than the other opening in the earth's gravitational field, or in the second teaching it is the only opening which is directly connected to the components for conveying the liquid. If the flow rate of both pumps is the same, the container is effectively bridged and the function of a continuous-flow heater results. In one embodiment, the upstream pump is the cold water pump. In an alternative or supplementary embodiment, the downstream pump is the hot water pump.

In one embodiment, the upstream pump is located in front of the heat exchanger, which in turn is followed by the opening of the container and then the downstream pump. For this constellation, the opening is located between the heat exchanger and the downstream pump.

In one embodiment, when the downstream pump (which is the hot water pump, for example) starts up, the supply of thermal energy to the heat exchanger and the upstream pump (correspondingly the cold water pump) are also started.

In one embodiment, at least one of the pumps used in the arrangement has a sufficiently large nominal flow rate, so that only a reduced flow rate is required in normal operation. This reduces noise during pumping.

According to a further embodiment, it is provided that an additional tank for storing the liquid is additionally present, and that the additional tank is arranged upstream, downstream or alongside the container with regard to filling with the liquid. In this embodiment, the storage volume of the container or of the arrangement as a whole is increased by an additional tank. Depending on the configuration, the container and the additional tank can be “connected in series” or “in parallel”. If the container has two openings and thus also the drain, the liquid flows through the drain into the additional tank and from there, depending on the design, into a fresh water tank or into a gray water tank. In this embodiment, the additional tank is therefore arranged downstream of the container. Alternatively, the container and additional tank are connected to the same pipeline, which comes, for example, from the heat exchanger and leads in the direction of the fitting or the hot water pump. In this case, the container and the additional tank are therefore juxtaposed or connected in parallel. In one embodiment, the additional tank is designed as a retrofit variant that can be subsequently connected to a tank that has already been installed. The additional tank is made of a plastic, for example, and is connected, for example, next to or below the container. If the additional tank has its own outlet, then this is preferably provided with a temperature sensor—in analogy to the temperature sensor behind the outlet of the container.

In one embodiment, the container and/or the additional tank is spatially separated from the other components of the arrangement. For example, the container and/or the additional tank is located in the space of a vehicle, whereas the other components are below the vehicle floor (the so-called underfloor). Alternatively, the container is in the vehicle and the auxiliary tank is outside of it.

One embodiment provides that a decalcification device is present and that the decalcification device is arranged between a first pump, which conveys the liquid to be heated to the heat exchanger, and a second pump, which conveys gas and liquid in the direction of the first pump, that it adds a descaler to the liquid delivered by the second pump. The decalcifying device takes up a decalcifying agent, for example, and releases it into the liquid. The second pump is, for example, the vent pump and is primarily used to pump air out of the heated liquid. In the process, heated liquid also enters a return path. Since the liquid is heated, the decalcification is promoted. The return path preferably opens out in front of an intake port of the first pump, which pumps the liquid to be heated, that is to say cold, to the heat exchanger and through it. For example, the first pump is the cold water pump. By conveying the liquid with the descaling agent in the direction of the first pump, the first pump can pump this liquid enriched by the agent through the heat exchanger and thus decalcify it.

• 1 eine prinzipielle Darstellung einer Vorrichtung zur Erwärmung einer Flüssigkeit,
• 2 eine Ausgestaltung der Komponenten eines Systems zur Abgabe von erwärmtem Wasser,
• 3 die Ausgestaltung der 2 ohne Bezugszeichen, jedoch mit der Andeutung von Funktionsblöcken,
• 4 eine alternative Ausgestaltung eines Teils des Systems der 2,
• 5 eine weitere Ausgestaltung eines Systems gemäß einer zweiten Lehre,
• 6 eine zusätzliche Ausgestaltung des Bereichs um den Behälter,
• 7 eine Detailansicht einer alternativen Anordnung der 2 und
• 8 eine Detailansicht einer weiteren alternativen Anordnung der 2.

In detail, there are a number of possibilities for designing and developing the arrangement according to the invention. For this purpose, reference is made on the one hand to the patent claims subordinate to patent claim 1 and on the other hand to the following description of exemplary embodiments in conjunction with the drawing. Show it:

• 1 a basic representation of a device for heating a liquid,
• 2 an embodiment of the components of a system for dispensing heated water,
• 3 the design of 2 without reference numerals, but with the indication of function blocks,
• 4 an alternative embodiment of a part of the system of 2 ,
• 5 a further embodiment of a system according to a second teaching,
• 6 an additional design of the area around the container,
• 7 a detailed view of an alternative arrangement of the 2 and
• 8th a detailed view of another alternative arrangement of 2 .

The 1 shows schematically the basic structure of a device for heating at least one liquid. In a variant, the device also heats air. Overall, the device thus serves to heat fluids. Since the liquid in the illustrations described is water, only water will be used in the following. As shown below, the device can be connected to further peripheral components in order to form an arrangement (or a system) for heating fluids overall. The arrangement is for example in a caravan, a mobile home or on a boat. The arrangement is therefore preferably arranged in or relative to a movable interior.

The thermal energy for heating is generated by the energy unit 1 by burning a fuel-air mixture and/or by electrical energy and is transferred to the liquid by the heat exchanger 2 . For this purpose, a cold water pump 11 pumps the cold water to be heated - e.g. B. from a fresh water tank of a vehicle or another cold water tank - through the heat exchanger 2 therethrough. The heated water is introduced into a hot water tank 3 and from there it reaches a fitting 5. The arrangement of the inflow and outflow courses is purely exemplary here.

Cold water is also fed to the fitting 5 through a cold water path 4, with a cold water path pump 12 being present. In one embodiment, the cold water comes from the cold water tank mentioned above. In the embodiment shown, the heated water and the cold water are brought together in a mixing section 30 so that water that has been heated to a desired temperature reaches the fitting 5 .

For the processes in the device, a control device 6 is also available, the z. B. acts on components of the device or the system described below based on measured values. In one variant, the control device 6 controls the energy unit 1 and thereby also the heat exchanger 2 or the heating process. In one variant, this is time-controlled. Alternatively or additionally, the heating process is started by a user. In a - not shown - execution triggers the user to start z. B. via a switch or an app functionality.

In the 2 a system is shown which makes heated service water available at the fitting 5 . The system can also be referred to as an arrangement. Although the system shown corresponds to the first teaching of the invention, the description largely also applies to the system according to the second teaching.

The system is described below, starting from a cold water tank 10 to the fitting 5. In the application shown here, all supply and discharge lines to and from the cold water tank (e.g. a fresh water tank of a vehicle or a mobile home, etc.) 10 open below the liquid level. Furthermore, the cold water tank 10 is open to the atmosphere so that it is always at atmospheric pressure.

The water leaves the cold water tank 10 via three paths: On the one hand, it is pumped into a hot water tank 3 via a cold water pump 11 and, on the other hand, it gets directly via the cold water path 4 to the cold water path pump 12, which is a vehicle pump, for example Tap 5 to allow the user to set the desired temperature. Furthermore, the water can get from the cold water tank 10 into the hot water tank 3 via the outlet 13 of the tank 3 .

Water enters the cold water tank 10 and thus out of the system via the already mentioned drain 13 from the hot water tank 3. The drain 13 is here in the bottom of the hot water tank 3 and is permanently open. Due to the position of the drain 13 at a low point of the hot water tank 3, the bottom layer of water flows out first, which is in particular the coldest layer of water.

As already indicated, water from the cold water tank 10 can also get into this lower area of the hot water tank 3 when the hot water pump 20 is actuated, depending on the flow rates of the pumps 11 and 19 . Connect for that det a hose or pipe the outlet 13 with the cold water tank 10, wherein the hose or the pipe opens below the liquid level in the cold water tank 10.

Between the drain 13 and the cold water tank 10 there is a water drain temperature sensor 14 which allows the temperature of the drained water to be measured. In an alternative embodiment—not shown—the water outlet temperature sensor 14 is integrated in the outlet 13 . Assuming that the coldest water is draining and that there is a target temperature for the warm water (see description below), the measured temperature can be used to determine what degree of filling with water that is at the desired temperature. In addition, the measured values of the water outlet temperature sensor 14 allow the control of the heat exchanger 2 or the associated energy unit 1.

First, the path of the water that leads through the hot water tank 3 is described.

A cold water temperature sensor 15 detects the temperature of the water that the cold water pump 11 delivers from the cold water tank 10 . In one configuration of the system, the cold water temperature sensor 15 allows the intelligent control of the cold water pump 11 by pilot control and/or predictive control. In the embodiment shown here, the cold water pump 11 is self-priming, for example a gear pump, so that it can also fill its intake line with water if it is arranged above the cold water tank 10, as indicated here.

The cold water pump 11 moves the water in a loop through the hot water tank 3 in the illustrated embodiment. The loop serves as a cooling section to protect the cold water pump 11 in the event that it is operated in reverse (see the following description of draining the heat exchanger 2). In an alternative embodiment - not shown here - the loop is omitted and the cold water pump 11 conveys the water directly to the heat exchanger 2.

In the heat exchanger 2, the water is heated by z. B. an electric heating element is used as the energy unit 1 or by the thermal energy of flue gas or other gases, z. B. hot room air, which has been heated heat exchanger - not shown here - is transferred.

Downstream from the heat exchanger 2 there is a hot water temperature sensor 16 which measures the temperature of the heated water. Based on the measured temperature, the flow rate of the cold water pump 11 is regulated (indicated by the dashed line), so that a predetermined setpoint temperature of the heated water is set. For example, if the water is too hot, the delivery rate is increased. If it is too cold, less water is pumped. In one embodiment, the temperature measurement by the cold water temperature sensor 15 is added to the regulation.

The scheme is by a - not shown here, but z. B. in the 1 indicated - control device 6 made. In one embodiment, the control device 6 performs further steps: If, for example, thermal energy is started to be supplied to the heat exchanger 2, the cold water pump 11 is started at the same time with a minimum flow rate in order to pump water through the heat exchanger 2 and thus also to the hot water temperature sensor 16 support financially.

In one embodiment, the target temperature of the water to be heated is variable. This makes it possible to reduce limescale deposits in the heat exchanger 2, which can be expected under certain circumstances, by reducing the temperature of the water to be heated and kept available.

In order to conserve resources, one embodiment provides that heating to the highest temperature is only carried out when the full nominal hot water capacity is to be called up soon, ie when the user opens the fitting 5 soon. The user can do this e.g. Communicate to the controller, for example, by pressing a button.

For the gas dissolved in the water, which forms bubbles when the water is heated, there is a ventilation valve 17 which automatically removes air bubbles from the line section behind the heat exchanger 2 by establishing a connection with the environment. The ventilation valve 17 is preferably located—like the connecting piece of the ventilation pump 19—at a high point in the liquid line.

In one embodiment - not shown here - the ventilation valve 17 consists of two components, each of which serves individual functions: there is a component for discharging the air (this is e.g. in the form of an automatic air vent with a float , as is usual in heating construction) and there is a component that allows air to enter the system when the cold water pump 11 runs backwards. The basic structure is as in 2 indicated: A floating body is formed by the Water pressed against an overhead opening in a seal. If there is no water, the floating body falls down due to gravity and opens up to the environment. Therefore air can penetrate.

The cold water pump 11 conveys the heated water from the heat exchanger 2 against an overflow valve 18, which in the embodiment shown is implemented similarly to a spring-loaded check valve, to a line area where the water either flows into the hot water tank 3 via an inlet 21 or through a hot water pump 20 is promoted further in the direction of the valve 5. The inlet 21 is located in an upper area of the hot water tank 3, so that the warm water also collects in an upper liquid layer and due to the water flowing in or the lower water layers flowing out through the outlet 13 - in the direction of gravity or in the direction the bottom of the hot water tank 3 - sinks.

The purpose of the overflow valve 18 results from the following context: The overflow valve 18 is designed in such a way that it remains closed until a certain differential pressure between the two line sides to which it is connected is exceeded. If—as shown here—the hot water tank 3 is higher than the cold water tank 10 , then there is a slight negative pressure along the hot water tank 3 , based on the height of the water column. If the overflow valve 18 were to open as a result of this small pressure difference, the hot water tank 3 would be filled with air via the ventilation valve 17 and in particular via its ventilation function. The overflow valve 18 is therefore designed in such a way or, in the case shown here, the spring is so strong that the overflow valve 18 remains closed even when the hot water pump 20 is running at full load and thus generates a greater negative pressure in the hot water tank 3 than is possible on its own would be set by the water column. Only the delivery pressure of the cold water pump 11 is able to overcome the spring force or generally open the overflow valve 18 and convey water to the hot water tank 3 .

The overflow valve 18 results in a pressure drop in the pumped water, so that further gas can escape from the water in the form of bubbles. This gas is discharged via the venting pump 19. The line sections between overflow valve 18, hot water pump 20 and outlet 21 are preferably designed in such a way that they form a high point to which the gas automatically flows, in that the supply/discharge lines rise steadily there. The venting pump 19 sucks off the gas preferably at this high point.

The venting pump 19 also functions as a check valve, so that in one embodiment—not shown here—two components form the venting pump 19 (one for the pump function and one for the function as a check valve). This additional function of the vent pump 19 is required so that the hot water pump 20 only draws in heated water and not water or gas that has been discharged via the vent pump 19 . In the exemplary embodiment, the venting pump 19 is designed as a membrane pump, which also fulfills the function of a check valve.

In one embodiment, the control device 6 automatically activates the venting pump 19 while thermal energy is being supplied to the heat exchanger 2 . In a further embodiment, the venting pump 19 is operated intermittently in order to improve the evacuation of gas and at the same time remove as little hot water as possible from the hot water tank 3 .

Since the process of pumping out gas is usually accompanied by the fact that water is also pumped out, the return line 31, which starts from the venting pump 19, opens out in front of the cold water pump 11. The gas is then discharged through the ventilation/venting valve 17. The water pumped out by the venting pump 19 mixes with the water from the cold water tank 10 in the suction line of the cold water pump 11 and is conducted through the heat exchanger 2 again. No thermal energy is lost by discharging the air.

The feeding area of the water returned by the venting pump 19 upstream of the cold water pump 11 is selected in one embodiment such that the water from the venting pump 19 enters the intake line of the cold water tank 10 but does not flow into it. In this embodiment, the recirculated water is thus moved again in the direction of the heat exchanger 2 by the cold water pump 11 . The venting pump 19 is in particular operated intermittently. The advantage of this is that a storage reservoir for warm liquid forms between the cold water pump 11 and the cold water tank 10 .

In one embodiment, the venting pump 19 is operated continuously. In an alternative embodiment, the venting pump 19 is operated intermittently, ie with interruptions. This has the advantage that the removal of air is promoted without too much heated water being removed.

The hot water pump 20 conveys the water in the direction of the fitting 5 and, if necessary, takes water from the hot water tank 3 via the inlet 21. Depending on the delivery rate of the cold water pump 11 and the hot water pump 20, the behavior of a boiler is therefore obtained (water is pumped out of the hot water tank 3 removed) or a flow heater (heated water goes directly to the fitting 5). If water is removed from the hot water tank 3 via the inlet 21 located above, water is refilled from below via the outlet 13 from the cold water tank 10 by the negative pressure generated by the hot water pump 20 . This ensures that there is no air in the hot water tank 3 .

Downstream from the hot water pump 20 are a branching check valve 22—also spring-loaded in the embodiment—and a first mixing path check valve 23. The branching check valve 22 is described below with reference to the emptying of the hot water tank 3.

The first mixing path non-return valve 23 ensures that the heated water only moves in the direction of a mixing section 30 which opens onto the fitting 5 . Furthermore, it ensures that the cold water path pump 12 cannot push cold water backwards into the hot water tank 3 via the hot water pump 20, regardless of its outlet pressure. This is relevant, for example, for the case—shown here—that the hot water pump is designed as a gear pump without a check valve functionality. In addition, it ensures that the pressure in the line system to fitting 5 is maintained when no water is drawn from there. This is particularly important when the chilled water path pump 12 is controlled by a pressure switch 26 (as in the illustrated embodiment).

In an alternative embodiment (not shown), a pressure reducer is provided, preferably directly after the cold water path pump 12 , which lowers the outlet pressure of the cold water path pump 12 to a pressure level similar to that of the hot water pump 20 . This prevents the two pumps 12, 20 from interfering with each other's operation.

To understand the mixing section 30, the cold water path 4 will now be described. The cold water path pump 12 conveys the water from the cold water tank 10 in the direction of the fitting 5. The cold water reaches the fitting 5 directly and also via a branch to the mixing section 30. In the branch line from the cold water path 4 to the mixing section 30 A second mixing path check valve 24 is present, which allows the cold water to flow onto the mixing section 30 only in this direction. It is thus ensured that when the outlet pressure from the cold water path pump 12 is low, no hot water is routed in the direction of the cold water tank 10 or the side of the cold water connection of the mixing fitting 5 . This is particularly true when the cold water path pump 12 allows a back flow of the pumped medium, as z. B. is the case with centrifugal or submersible pumps.

If the two pumps 12 and 20 are well matched to one another with regard to their delivery quantities and pressures, then in a further embodiment the two mixing path non-return valves 23 and 24 can be dispensed with (not shown). This applies in particular when the pumps 12 and 20 are not controlled via a pressure switch 26 but, for example, via an electrical switch integrated in the mixer fitting 5 (not shown).

The water that has been heated to a predetermined desired temperature and the cold water coming from the cold water tank 10 thus reach the mixing section 30 . The temperature of the mixed water is detected by a mixed temperature sensor 25 . Based on the measured temperature and a predetermined target mixed temperature - has a regulating effect on the flow rate of the hot water pump 20 - in the embodiment shown. This is with the aim of setting the specified target mixing temperature. This is therefore the maximum temperature that the water can have when it exits the fitting 5 . This provides the user with protection against scalding.

In a supplementary or alternative embodiment, the flow rate of the cold water path pump 12, which is a vehicle pump, for example, is acted upon: When the control of both pumps 12, 20 is combined, the control of the cold water path pump 12 results in the advantage for the cases that the hot water pump 20 is reaching its performance limit or that the water in the hot water tank 3 has only cooled down a little or has not been heated up that much, and that the mixed temperature has fallen below the target value in each case. Therefore, for example, the amount of water at the fitting 5 is reduced in favor of the water temperature remaining the same.

In one variant, the user can specify the target mixed temperature with which the measured values of the mixed temperature sensor 25 for controlling the hot water pump 20 are compared. If the user then adjusts the faucet 5 only to hot water, he receives water with the desired target mixed temperature.

In an alternative variant (not shown) there is no direct connection between the cold water tank 10 and the fitting 5. There is therefore no manual mixing by the user. This is replaced by the user specifying the desired mixing temperature and by controlling based on the temperature measured by the mixing temperature sensor 25 . For example, if the user wants the water to have a temperature of 38° C., the hot water pump 20 is controlled in such a way that it mixes the appropriate amount of hot water with the cold water pumped by the cold water path pump 20 .

In the cold water path 4 there is also a pressure switch 26. This detects the actuation of the fitting 5 and the resulting drop in pressure. Based on this, the hot water pump 20 and the cold water path pump 12 are started, so that water is available at the fitting 5 . Conversely, if the cold water path pump 12 is switched off, the hot water pump 20 is also switched off. In one embodiment, the cold water path pump 12 is a submersible pump (or centrifugal pump) which z. B. is switched on by a microswitch on the fitting 5, and so this microswitch also turns on the hot water pump 20 at the same time (or off accordingly). If the cold water path pump 12 is designed as a pressure pump (e.g. in the form of a diaphragm pump), the pressure switch 26 can be part of the pump 12 .

The relevant temperatures in the system are, for example, the following: The cold water has a temperature of 13 °C. The temperature of the heated water is 80 °C, so that germs in the water, e.g. B. legionella, are avoided. The temperature of the mixture of heated water and cold water is 50°C. If the user himself mixes a water temperature at the fitting 5, this can in principle be between 13° C. and 50° C. for these example values.

The following describes how the system allows the hot water tank 3 and the heat exchanger 2 to be emptied of water. For this purpose, the cold water pump 11 and the hot water pump 20 are designed in such a way that they can pump medium and also two different media (water as liquid and air as gas) in two directions. They are therefore self-priming. In one embodiment, the pumps 11, 20 (as shown) are designed as gear pumps. So far, the use of the forward direction has been described.

In order to empty the heat exchanger 2 of water, the cold water pump 11 is reversed in its conveying direction. The overflow valve 18, which is located between the heat exchanger 2 and the inlet 21 of the hot water tank 3 or the hot water pump 20, closes the line automatically. No water can therefore flow back from this side in the direction of the fitting 5 .

If the cold water pump 11 conveys backwards, then air from the environment flows through the ventilation valve 17 into the line and in particular through the line section which extends through the heat exchanger 2 . The line is thus emptied and the heat exchanger 2 cannot heat any liquid.

Emptying is z. B. relevant if the heat exchanger 2 is intended to heat not only liquid but also room air, and if it is provided in particular that there is a pure air mode in which only room air and no liquid is heated. Furthermore, in the air mode, thermal energy is supplied to and transferred from the heat exchanger 2, which energy can be associated with a temperature above the boiling point of water. The aim of emptying the line in the area of the heat exchanger 2 is to avoid noise or pressure shocks when the liquid evaporates. Therefore, the generally cold ambient air penetrating through the ventilation valve 17 entrains the water vapor produced when heat is introduced into the heat exchanger 2 before the above-mentioned disruptive phenomena occur.

In this operating mode, air and water vapor are pumped into the cold water tank 10 for emptying the heat exchanger 2, where they can escape again to the environment.

In order to reduce the risk of the cold water pump 11 being damaged by such a hot vapour/air mixture, in one embodiment it can be guided in a loop through the hot water tank 3 and cooled before it passes the cold water pump 11 (as shown). . The loop serves as a cooling section to protect the cold water pump 11.

If, for example, for the cold season or for a longer period of non-use or z. B. be emptied for cleaning purposes of the hot water tank 3, the hot water pump 20 is operated in the reverse direction. In addition, the cold water pump 11 does not deliver any water and the venting pump 19 is also not active.

If the hot water pump 20 conveys the water away from the fitting 5 in the direction of the inlet 21 of the hot water tank 3, then the first one closes Mixing path non-return valve 23 and via the branching non-return valve 22 air can enter the line from the environment around the arrangement and be conveyed by the hot water pump 20 in the direction of the hot water tank 3 .

The branching check valve 22 is designed in such a way that it does not open due to the slight negative pressure that occurs in the hot water tank 3 due to the difference in height between the outlet 13 or the cold water tank 10 and the inlet 21, but only when there is a correspondingly large negative pressure, such as it is generated by the hot water pump 20 in reverse direction operation on the check valve 22 side. In one embodiment, the check valve 22 is designed as a spring-loaded check valve or as an overflow valve.

The water flows out of the bottom of the hot water tank 3 through the outlet 13 and is displaced by the ambient air pumped into the top of the tank 3 until the hot water tank 3 is empty.

The filling of the heat exchanger 2 takes place in that the cold water pump 11 - self-priming - pumps liquid to the heat exchanger 2, as a result of which air is displaced there and leaves the arrangement into the environment via the ventilation valve 17. For this purpose, the line section between the heat exchanger 2 and the overflow valve 18 is preferably designed and arranged in such a way that the ventilation valve 17 is located at a high point between them.

Based on the previous description, two variants for filling the hot water tank 3 are described. This is done via the venting pump 19, with the cold water pump 11 being able to be dispensed with. Alternatively or additionally, the filling is done by the hot water pump 20, which is operated while the fitting 5 is open and the cold water path pump 12 is not active. In both cases, water is drawn from the cold water tank 10 into the hot water tank 3 via the outlet 13 .

The hot water tank 3 has a total of two openings: an upper 21 and a lower 13. In the description, the upper opening 21 is referred to as the inlet, insofar as the heated water enters the tank 3 via the inlet 21. However, the opening also serves as an outlet, since the hot water pump 20 can remove the heated water via it. The lower opening 13 is referred to as a drain insofar as the water flows out through it when warm water or air enters the container 3 via the inlet 21 . However, the opening also serves as an inlet for water from the cold water tank 10, e.g. B. when the hot water pump 20 takes water from the container 3 via the inlet 21 - which in this case acts as an outlet. Thus both openings 21, 13 could also be referred to as inlet/outlet openings.

Depending on the configuration, the system described here is composed of the components of a device for heating water and correspondingly associated peripheral components. In one embodiment, the system (alternative name: arrangement) is composed of such a device and the cold water tank 10, with the connection between the two being via a corresponding number of lines (ie hoses or pipes). In an alternative embodiment, the device does not include the fitting 5, so that the device is connected to the cold water tank 10 and the fitting 5 as external components. In an alternative embodiment, the cold water path pump 12 does not belong to the device, but is, for example, a vehicle pump, as z. B. is common in mobile homes. In this configuration, the device therefore includes corresponding interfaces for controlling the cold water path pump 12 or for detecting its operating state. Correspondingly, the fitting 5 can also be part of the periphery of the device here.

Is indicated in the 2 furthermore, a decalcifying device 7, which is located in the return line 31 between the vent pump 19 and the cold water pump 11. This is, for example, a device into which a decalcification agent can be introduced and which adds the decalcification agent to the returned liquid.

A decalcification process is described below, which is characterized in that as little decalcification agent as possible gets into the cold water tank 10 . The pumps 11, 19, 20 and the heat exchanger 2 are reliably descaled.

The ventilation pump 19 and the cold water pump 11 are in operation, with the energy unit 1 supplying only little thermal energy to the heat exchanger 2 . The flow rate of the cold water pump 11 is adjusted in such a way that the cold water temperature sensor 15 only measures the temperature of the water from the cold water tank 10 and not of the recirculated water. As a result, no recirculated water provided with descaling agent flows into the cold water tank 10. In addition, the water to which the descaling agent has been added is slightly heated, which speeds up the descaling process.

The cold water pump 11 is operated in such a way that it delivers more than the vent pump 19, so that water also reaches the tank 3. In order to prevent the descaler from getting into the cold water tank 10 via the drain 13, the hot water pump 20 is in operation when the fitting 5 is open. In addition, the cold water path pump 12, which is, for example, a vehicle pump, is preferably not in operation.

Based on the temperature measurements of the mixing temperature sensor 25, the control device 6 reverses the direction of action in contrast to normal operation by setting a larger flow rate of the hot water pump 20 if the temperature measured in the mixing section 30 is above the setpoint (in normal operation the flow rate can be reduced). In addition, a target value is set that is slightly lower than the measured value of the hot water temperature sensor 16 . As a result, the hot water pump 20 increases the flow rate by increasing its speed. As a result, it pumps a larger volume of water than hot water enters the container 3. It thus draws fresh water out of the cold water tank 10 via the container 3 . The outlet 13 of the container 3 thus allows filling from the downstream cold water tank 10 .

For the decalcification of the container 3 it is provided in one operating mode that the hot water pump 20 is not operated or is only operated with a low flow rate, so that the water provided with decalcifying agent and heated reaches the container 3 .

In a variant—not shown—there are sieves at various points in the line system, which collect lumps of lime before they render components such as valves or pumps unusable.

Insofar as the pumps used (hot water pump 20 and cold water pump 11) are gear pumps, their ability to convey air can be improved by conveying a little water at the same time. The water serves as a kind of "sealant" and reduces internal leakage and backflow of air. This increases the amount of air delivered and the delivery pressure. This in turn allows the pumps to be designed smaller or to be operated quietly, since a sufficient amount of air is conveyed. This is in contrast to a membrane pump, for example, as can be provided as a variant of the venting pump 19 .

• Die - hier nicht dargestellte - Anordnung ist dabei derart, dass es ein Gefälle der Flüssigkeitsleitung vor dem Zulauf der Pumpe 20 gibt. Fördert somit die Heißwasserpumpe 20 rückwärts und damit in Richtung des Behälters 3, so verdrängt sie zunächst Wasser, das nach oben geschoben wird. Die Leitung, die im Normalbetrieb Zuleitung zu der Pumpe 20 ist und die sich entgegen des Erdschwerefelds oberhalb der Pumpe 20 befindet, wird in der Regel ein paar Tropfen Wasser enthalten, welche in die Pumpe 20 zurückströmen, wenn sie kurzzeitig ausgeschaltet wird. Dann ist wieder „Dichtmittel“ da, und sie kann wieder besser Luft fördern. Daher wird die Heißwasserpumpe 20 für die Förderung von Luft intermittierend betrieben.
• In einer - nicht dargestellten - Ausgestaltung befindet sich oberhalb der Heißwasserpumpe 20 eine Rohrverdickung, sodass bei Stillstand der Pumpe 20 stets ausreichend Wasser zurück- bzw. nach unten in die Pumpe 20 läuft. Die Verdickung ist dabei groß genug, sodass die geförderte Luft das darin enthaltene Wasser nicht vollständig mitreißt.

For this purpose, the hot water pump 20 is considered first:

• The arrangement--not shown here--is such that there is a gradient in the liquid line in front of the inlet of the pump 20. Thus, if the hot water pump 20 promotes backwards and thus in the direction of the container 3, it first displaces water, which is pushed upwards. The line, which is the supply line to the pump 20 in normal operation and which is located above the pump 20 against the earth's gravitational field, will usually contain a few drops of water, which will flow back into the pump 20 if it is switched off for a short time. Then "sealant" is there again and it can pump air better again. Therefore, the hot water pump 20 is intermittently operated to feed air.
• In one embodiment--not shown--there is a thickened pipe above the hot water pump 20, so that when the pump 20 is at a standstill there is always sufficient water running back or down into the pump 20. The thickening is large enough so that the conveyed air does not completely entrain the water it contains.

• Für die Kaltwasserpumpe 11 ist eine Ausgestaltung vorgesehen, die in der 7 dargestellt ist. Die Rückführleitung, in welche die Entlüftungspumpe 19 die Luft und auch Wasser fördert, mündet an einem Bereich, der sich oberhalb des Ansaugstutzens der Kaltwasserpumpe 11 befindet. Zu diesem Ansaugstutzen gelangt entsprechend auch das Wasser aus dem Kaltwassertank 10, dessen Temperatur durch den Kaltwasser-Temperatursensor 15 erfasst wird.

The application for the cold water pump 11 is also considered:

• For the cold water pump 11, an embodiment is provided in the 7 is shown. The return line, into which the venting pump 19 conveys the air and also the water, opens out at an area which is located above the intake port of the cold water pump 11 . The water from the cold water tank 10 , the temperature of which is detected by the cold water temperature sensor 15 , also reaches this intake port accordingly.

The cold water pump 11 sucks water from the cold water tank 10 itself and bleeds the heat exchanger 2, which may have to be done each time before water is heated: If the heat exchanger 2 has been ventilated beforehand, air gets through the cold water pump 11 into the cold water tank 10.

Alternatively, according to the design of the 7 The following is provided: The venting pump 19 pushes small amounts of water at intervals via the return line in front of the intake port of the cold water pump 11. This means that the pump 11 always has enough "sealant" to suck in from the cold water tank 10 in order to suck efficiently. The upstanding suction port of the cold water pump 11 encourages water to run into it.

In the arrangement of 2 Three lines lead to the cold water tank 10: a line to take water that is to be heated, a line to take cold water for the faucet 5 or the mixing section 30, and a line to take water from the drain 13 of the container 3 enters the cold water tank 10. In order to enable these lines to be protected against frost, the lines are arranged next to one another in an embodiment--not shown here--so that there is a common hose with three channels. The end portions of the channels in the cold water tank 10 are sufficiently diverged to prevent water from flowing directly from one channel into another.

This design with the parallel lines allows an elegant way of heating the lines to prevent frost: In the event that the arrangement is not operated or that at least no hot water production takes place, the vent pump 19 is occasionally operated to a small amount of warm To feed water via the return line into the hose that connects the cold water tank 10 to the cold water pump 11, which is not active at these times. This warm water also heats up the neighboring hoses or channels. This process is temperature and/or time controlled. This prevents the hose from freezing.

In the 3 is the system of 2 shown again to describe the individual functional units separately. The individual reference symbols are omitted for clarity; it will rather be on the 2 referred. The description also applies accordingly to the arrangement according to the second teaching, as exemplified in 5 is shown.

The system includes a functional block A, in which regulation to the desired temperature of the heated water takes place.

For this purpose, the temperature of the water heated after contact with the heat exchanger is measured and based on this - here as an example - the cold water pump, which transports the water to be heated through the heat exchanger, is regulated accordingly. The pump flow rate is thus continuously regulated so that water at the desired temperature reaches the inlet of the hot water tank or further towards the tap. The heated water that flows into the hot water tank displaces the water in it, which is particularly cold. (As will be explained below, the arrangement according to the second teaching of the invention causes the tank 3 to expand.) The cold water flows out of the hot water tank and the hot water tank fills with the water which has the desired temperature and which can also be conveyed to the fitting. As already mentioned, the pumping function can be taken over by the cold water pump, the vent pump or the hot water pump.

The functional block B serves to discharge the air dissolved in the water, which is released when the water is heated. Furthermore, the air can be removed, z. B. is in the still empty hot water tank or the still empty heat exchanger before an initial filling.

This pursues the goal that no air can collect in the hot water tank, which would have a disruptive effect on the operation of the hot water pump and which would also lead to admixture of air at the extraction fitting. Air in the container would also have a negative impact on the usable heat capacity of the container.

The air that is released from the water when it is heated escapes from the pipe system via a ventilation valve. To the extent that air remains in the water downstream after passing through the vent valve, a pressure drop across a spill valve will cause it to escape from the water and be purged via a bleed pump. The air and the water that may be pumped along with it when it is pumped out are fed back into the pipework for heating the water before the heat exchanger. The air - now in an undissolved state - therefore reaches the ventilation valve again and is discharged there into the environment. The thermal energy of the water is not lost because the water is recycled.

It is not necessary to operate the cold water pump for the initial filling of the hot water tank; in this case, the air extracted by the bleed pump is discharged into the fresh water tank.

In the functional block C, a constant delivery temperature of the water is set, which does not exceed a maximum value limit. This block C is found in the arrangements of both teachings.

In the mixing block C, the heated water and the cold water are mixed in such a way that the water delivered via the faucet cannot be warmer than a maximum temperature. This prevents a user from being scalded and is also a convenience function. The maximum temperature is lower than the target temperature generated by the warm-up block A.

A mixing section is provided for this purpose, in which the heated water is introduced via a hot water pump and the cold water is introduced via a pump. A mixing temperature sensor records the temperature in the mixing section and the flow rate of the heated water is regulated based on the measured value. In one embodiment, the mixing block C allows you to set the temperature at which the water from the fitting, ie z. B. from the faucet or from a shower head. It is therefore not necessary for the user to regulate the temperature manually. He only has to enter a target value. In one embodiment, the flow rate of the cold water is regulated as an alternative or in addition.

In one embodiment, the mixing block C is a separate device which is connected to other components in the periphery via appropriate interfaces—in particular with regard to the conduction of liquid.

The functional block D is used to switch on the mixing block C.

If e.g. If, for example, a pressure switch or a microswitch integrated in the fitting determines that the fitting is open and water is draining, the pumps for the cold water and for the heated water are switched on. The mixing then also takes place through the mixing block C. The heated water comes directly from the heat exchanger and/or is taken from the hot water tank. After opening the faucet, water is immediately available to the user.

The functional tank drain block E is used to drain the hot water tank. This applies to the arrangement according to the first teaching. The emptying of the container 3 in an arrangement according to the second teaching is described below.

For emptying, the pump, which transports the heated water towards the fitting, is operated in reverse. This opens a check valve or overflow valve that is connected to the ambient air. The check valve only allows air to flow in one direction and only when there is a certain pressure differential. The pump thus first delivers water, which is in the line, and then air to the inlet of the hot water tank. The pumping also causes the mentioned pressure difference to let the air in via the check valve. During normal operation, the pump takes the water from the hot water tank via the inlet. Since the pump, which is active in the warm-up block A and there in normal operation conveys the cold and then the warmed-up water in the direction of the hot-water tank, is switched off, no new water flows from there in the direction of the inlet. In addition, the priming pump is switched off. The water flows out of the hot water tank via the drain and the reverse-running pump empties the hot water tank.

It may be necessary to prevent the water from being heated by the heat exchanger. This is e.g. This is the case, for example, when the heat exchanger is intended to heat air and not water in one operating mode. Remaining water in the line would evaporate and cause noise. Therefore, the functional heat exchanger drain block F is present. The block F can again be realized with both teachings.

In this function block F, the pump that delivers the water to be heated is operated backwards and thus draws the remaining water out of the area of the heat exchanger. The ventilation valve, which has already been described in connection with the ventilation block B and acts as a ventilation valve in this operating case, helps here. Air from the environment thus enters the line and pushes the remaining water in the direction of the reverse-running pump.

Another functional block—not shown for the sake of clarity—is used to decalcify pumps 11, 19 and 20 and heat exchanger 2. Reference is made here to the above description of FIG 2 .

4 shows part of a variant of the system described above. In this embodiment, the previously heated water from the hot water tank 3 flows out of the outlet 13 into a gray water tank 27, which is preceded by a gray water tank non-return valve 29. The valve 29 only allows flow in the direction of the gray water tank 27. The cold water flows from the cold water tank 10 via a cold water tank non-return valve 28 and through the outlet 13, which in this case serves as an inlet, into the lower area of the hot water tank 3 The outflow of water into the gray water tank 27 and the inflow of water from the cold water tank 10 are coordinated in such a way that no air flows into the hot water tank 3 . This variant prevents heated water from entering the cold water tank 10 .

In the 5 is an alternative to the variant of the 2 or. 3 shown. This is an example of the second teaching. Only the differences are discussed below. For those not discussed components, the explanations above apply.

The hot water tank 3 does not have a fixed, but a variable volume of liquid. This is indicated here by the bubble. Depending on the degree of filling, the container 3 can thus expand. A support structure, e.g. B. a grid.

Furthermore, the container 3 has only one opening 21, which can be located at any position and here only as an example at the top. The container 3 is designed in such a way that no air collects in it when it is filled with the liquid. For this purpose, the container 3 is, for example, designed to be correspondingly smooth and free of projections or areas of folds, etc.

In particular, the air is sucked off at a high point above the opening 21 by the ventilation pump 19 before it can reach the container 3 .

The two teachings agree that the container 3 is completely filled with liquid during the heating operation of the device or arrangement and that there is no air in it. This is achieved here, for example, in that the container 3 contracts when liquid is removed, instead of cold water flowing in from the cold water tank.

When arranging the 5 is accordingly no branching check valve 22 required, which in the arrangement of 2 it had made it possible to empty the local container with a fixed internal volume via the hot water pump 20 . Since this type of emptying of the container 3 is not necessary, it is sufficient if the hot water pump 20 delivers in the direction of the fitting 5 only. The pump 20 can therefore also be a diaphragm pump, for example.

• Hat der Behälter 3 sein maximales Innenvolumen erreicht, so kann kein weiteres Wasser von der Kaltwasserpumpe 11 hineingefördert werden. Daher muss entweder mit der Wasserentnahme über die Heißwasserpumpe 20 begonnen oder muss die Kaltwasserpumpe 11 gestoppt werden. Bei der zweiten Alternative wird ergänzend die Zufuhr von thermischer Energie zum Wärmeübertrager 2 beendet, da der Übertrager 2 sich sonst überhitzen könnte.
• Um den Behälter 3 - also beispielsweise die Blase - gezielt und vollständig zu entleeren, kann die Entlüftungspumpe 19 verwendet werden. Dabei muss die Kaltwasserpumpe 11 ausgeschaltet sein. Die Entlüftungspumpe 19 saugt den Behälter 3 leer und pumpt das Wasser über den Ansaugschlauch der Pumpe 11 zurück in den Frischwassertank 10.

By the container 3 does not have a second, permanently open opening as in the variant of 2 the operating behavior of the arrangement changes:

• If the container 3 has reached its maximum internal volume, no further water can be pumped in by the cold water pump 11 . Therefore, either the water extraction via the hot water pump 20 has to be started or the cold water pump 11 has to be stopped. In the second alternative, the supply of thermal energy to the heat exchanger 2 is additionally terminated, since the exchanger 2 could otherwise overheat.
• In order to empty the container 3 - for example the bladder - in a targeted and complete manner, the venting pump 19 can be used. The cold water pump 11 must be switched off. The venting pump 19 sucks the container 3 empty and pumps the water back into the fresh water tank 10 via the suction hose of the pump 11.

A fundamental difference between the two arrangements is that in the arrangement according to the second teaching of 5 in the event that the water in the bladder 3 has cooled down due to heat losses to the outside, it must first be pumped out if there is a need for warm water before the heat exchanger 2 and the cold water pump 11 can be put into operation. In the arrangement according to the first teaching of 2 With the two openings in the container, the heating of water via the heat exchanger 2 can be started immediately.

The 6 shows an embodiment according to the first teaching of the invention. The application to the second teaching is obvious.

Part of the arrangement around the container 3 is shown. You can see - not only in the drawing, but also in relation to the realized geometry - above the container 3 the overflow valve 18, the vent pump 19 and the hot water pump 20. In the direction of flow behind the outlet 13 of the container 3 there is an additional tank 3'. The auxiliary tank 3' is in particular arranged relative to the container 3 in such a way that the hydrostatic pressure in the container 3 remains unchanged. The additional tank 3' thus only increases the capacity. Therefore, the container 3 and the additional tank 3' could also be regarded as a unit for receiving the liquid. An outlet opening 13 ′ of the additional tank 3 ′ is coupled to the fresh water tank 10 . Thus, in this embodiment, the container 3 is connected indirectly to the fresh water tank 10 .

The variant of the arrangement of 6 can be transferred accordingly to the arrangement in the 5 is shown. However, the additional tank 3' then does not have an outlet opening 13'.

In addition to the water outlet temperature sensor 14, the additional tank 3' also has an additional tank temperature sensor 14', the measured values of which serve to control the arrangement.

In the 8th a connection of the arrangement to a fixed water connection 40 is shown. For the supply of the cold water tank 10 with water, a Float valve 41 provided that ensures automatic refilling.

In addition, the arrangement is designed in such a way that it is possible to dispense with the operation of the cold water path pump 12 . This is desirable, for example, when it is a vehicle pump that is designed as a pressure pump in order to reduce noise.

For this purpose, the fixed water connection 40 is not only connected to the cold water tank 10 via the float valve 41, but there is also a connection upstream of the valve 41 into the cold water path 4. The access opens out downstream behind the cold water path pump 12. After the fixed water connection 40 and before the branch to the cold water path 4 there is a first non-return valve which prevents water from being pumped into the water network. A second check valve is present downstream of the cold water path pump 12 and upstream of the access from the fixed water connection 40 and prevents the cold water tank 10 from being filled backwards via the cold water path pump 12 .

Preferably, the float valve 41 is automatically locked when the fixed water connection 40 is not connected to the arrangement. When the level in the cold water tank 10 is low, this prevents the cold water path pump 12 from pumping in the circuit only via the float valve 41 instead of building up pressure at the fitting 5 .

Reference List

1

energy unit

2

heat exchanger

3

hot water tank

3'

auxiliary tank

4

cold water path

5

fitting

6

control device

7

descaling device

10

cold water tank

11

cold water pump

12

Chilled Water Path Pump

13

indulgence

13'

exit port

14

Water outlet temperature sensor

14'

Auxiliary tank temperature sensor

15

Cold water temperature sensor

16

Hot water temperature sensor

17

ventilation valve

18

overflow valve

19

vent pump

20

hot water pump

21

inlet

22

branch check valve

23

first mix path check valve

24

second mix path check valve

25

Mixed temperature sensor

26

pressure switch

27

gray water tank

28

Cold water tank check valve

29

Gray water tank check valve

30

mixing section

31

return line

40

mains water connection

41

float valve

A

warm-up block

B

vent block

C

blend block

D

switch-on block

E

container emptying block

f

Heat exchanger drain block

Claims (8)

Arrangement for heating a liquid, with an energy unit (1), a heat exchanger (2), a container (3) and a pump (20), wherein the energy unit (1) supplies the heat exchanger (2) with thermal energy, wherein the heat exchanger (2) transfers the thermal energy to the liquid, wherein the container (3) receives the liquid, the container (3) having an opening (21), and the pump (20) being connected to the opening (21) of the container (3) and to the heat exchanger (2) in such a way that the pump (20) delivers liquid from the opening (21) and/or from the heat exchanger (2). . arrangement according to claim 1 , wherein a further pump (11) is present, wherein the further pump (11) liquid to be heated through the heat exchanger (2). transported, and wherein the opening (21) of the container (3) between the heat exchanger (2) and the pump (20) is arranged. arrangement according to claim 2 , wherein a temperature sensor (16) is present for measuring a temperature of the liquid heated by the heat exchanger (2), and wherein a control device (6) receives measured values from the temperature sensor (16) and uses them to control the further pump (11). Arrangement according to one of Claims 1 until 3 , wherein the pump (20) conveys heated liquid to a mixing section (30), there being a cold water path (4) which opens onto the mixing section (30), a mixing temperature sensor (25) for measuring a temperature of the liquid in of the mixing section (30), and wherein a control device (6), based on measured values from the mixing temperature sensor (25) and a predetermined temperature range, controls the pump (20) and/or a cold water path pump (12) for pumping the liquid in the cold water path (4) controls. Arrangement according to one of claims 2 until 4 there being a vent valve (17), the vent valve (17) allowing air to be evacuated from the assembly, there being an evacuation pump (19) for evacuating air and liquid through a return line (31). is, and wherein the return line (31) opens in front of the ventilation valve (17) and in front of the further pump (11). arrangement according to claim 5 , wherein there is a component (18) between the ventilation valve (17) and the ventilation pump (19) which opens when a predetermined pressure difference is exceeded so that the liquid can flow in the direction of the ventilation pump (19). arrangement according to claim 5 or 6 , the further pump (11) conveying air through the heat exchanger (2) in one conveying direction and liquid through the heat exchanger (2) in another conveying direction. Arrangement according to one of Claims 5 until 7 wherein a decalcification device (7) is present, and wherein the decalcification device (7) is arranged along the return line (31) in such a way that it adds a decalcification agent to the liquid delivered by the deaeration pump (19).

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