WO2024083998A1

WO2024083998A1 - Central heating system and method for operating and/or controlling and/or regulating a central heating system

Info

Publication number: WO2024083998A1
Application number: PCT/EP2023/079170
Authority: WO
Inventors: Peter Brecklinghaus
Original assignee: Peter Brecklinghaus
Priority date: 2022-10-20
Filing date: 2023-10-19
Publication date: 2024-04-25
Also published as: WO2024084000A1

Abstract

The invention relates to a central heating system (1) comprising at least one primary heat source (2) which can be operated with fuels, in particular a boiler and/or a gas heater, comprising at least one electrically operatable heat pump (3), at least one heat exchanger (4), preferably a heating element or a radiator for heating a building, and at least one service water reservoir (5). The invention also relates to a method for operating and/or controlling and/or regulating a central heating system (1). In particular, the fuel requirement for the primary energy source is minimized in a distributed manner over the year in that a temperature sensor (13.1) is arranged in a lower region of the service water reservoir (5), when viewed vertically, or adjacently to the lower region of the service water reservoir (5), when viewed vertically, in order to ascertain the actual service water temperature (TB1), and the temperature sensor (13.1) is connected to a heat pump control and/or regulating device (14) for control and/or signaling purposes and/or so as to transmit data. The heat pump (3) is connected to the heat pump control and/or regulating device (14) for control purposes, and the heat pump control and/or regulating device (14) is designed such that the heat pump (3) can be controlled and/or regulated on the basis of the ascertained actual service water temperature (TB1).

Description

Central heating system and method for operating and/or controlling and/or regulating a central heating system

The invention relates to a central heating system having the features of the preamble of patent claim 1 and a method for operating and/or controlling and/or regulating a central heating system having the features of the preamble of patent claim 16.

The central heating systems known in the prior art generally have at least one primary heat source that can be operated with the aid of fuels, in particular a boiler and/or a gas boiler. Some central heating systems also have an electrically operated heat pump, but at least one heat exchanger, preferably a heater or a radiator for heating a building, and/or a domestic water storage tank. A heat transfer fluid, in particular water, can be heated by means of the primary heat source and/or with the aid of the heat pump, wherein the heat transfer fluid, in particular previously heated, can be conveyed through the heat exchanger by means of a pipe system and by means of a heating pump. The heat transfer fluid can be conveyed by means of the pipe system, in particular with the aid of a circulating pump, for heating by the heat pump. By means of the pipe system and a storage pump, the heat transfer fluid can be conveyed to the domestic water storage tank for heating domestic water temporarily stored in the domestic water storage tank, in particular for heat transfer from the heat transfer fluid to the domestic water through or adjacent to the domestic water storage tank. The heat transfer fluid can be conveyed through or to the primary heat source by means of the heating pump, in particular the circulation pump, and/or the storage pump, wherein a central heating control and/or regulating device is connected to the primary heat source for control and/or regulation thereof.

DE 29 19 751 C2 describes a central heating system with a heat transfer fluid that can be heated or warmed with fuels in a boiler, wherein a heating circuit for heating radiators in a building is connected to the boiler and the heated heat transfer fluid flows through the heating circuit. The heating circuit has a heat exchanger inflow line, also called a flow line, via which the heat transfer fluid is fed to the heat exchangers designed as radiators. The heating circuit also has a heat exchanger outflow line, also called a return line, via which the Heat transfer fluid is then fed from the radiators back to the boiler. A boiler for domestic water heating is installed in the boiler. The heat transfer fluid can be fed to a heat pump from the heat exchanger inlet line of the heating circuit and then fed back at an increased temperature from the heat pump into the heat exchanger outlet line of the heating circuit. In addition to the usual temperature sensors for controlling the boiler, two temperature sensors are arranged in a heat pump inlet line leading to the heat pump, while another temperature sensor measures the temperature of the supply air that is fed to an evaporator of the heat pump. The heat pump and boiler can each be operated separately or simultaneously. The heat pump is not operated below an outside temperature of 3°C or 5°C for economic reasons. In a range around this 3°C or 5°C, the actual heat transfer fluid temperature at the boiler is kept at 55°C by means of the boiler, so that the heat pump is not switched on as often.

Boilers arranged in heating boilers for heating domestic water usually have only a small storage volume, so that the domestic water must be heated quickly, i.e. with high output, when the central heating system is operating. However, such high output requires the operation of the heating boiler, particularly in addition to the operation of the heat pump, so that there is a very high demand for fuels throughout the year. The fact that the heat pump is only operated above an outside temperature of 3°C or 5°C further increases the demand for fuels. Around the outside temperature range of 3°C or 5°C (or below), the heating boiler is preferably operated and the heat pump is only switched on when required and only rarely, so that heat is preferably provided by the fuels in the aforementioned temperature range.

DE 30 24 714 A1 shows another central heating system with a heat transfer fluid that can be heated or warmed up with fuels in a boiler. A heating circuit for heating a building using the heat transfer fluid flowing through the building's underfloor heating is connected to the boiler. The heat transfer fluid can also be used to heat domestic water in a domestic water storage tank, with the heat transfer fluid being pumped to the domestic water storage tank by means of a storage pump. The heating circuit has a heat exchanger inflow line, also called a flow line, through which the heat transfer fluid is fed to the underfloor heating. The heating circuit also has a heat exchanger outflow line, also called a return line, through which the heat transfer fluid is fed from the underfloor heating and then back to the boiler via the domestic water storage tank. The heat transfer fluid is connected to a heat pump from the The heat exchanger drain line can be fed from the heating circuit and from the domestic hot water tank, whereby after heating in the heat pump the heat transfer fluid can be returned from the heat pump to the boiler at an increased temperature. A temperature sensor is arranged directly in front of an inlet connection of the heat pump. By connecting the heat pump to the heat exchanger drain line, the heat transfer fluid, e.g. water, heated by the heat pump to 50-55°C, is always fed through the boiler, even when the heat pump is in pure operation. By means of the temperature sensor arranged in the heat exchanger drain line, an actual return temperature prevailing there is used as a kind of reference variable for the entire central heating system, in such a way that after specifying a certain target return temperature, which can be 45°C, for example, the required heating output of the heat pump, by means of which the heat transfer fluid is then to be heated by around 10°C, is then generated in such a way that the heat pump, which is present for this purpose as part of a priority control, always works or is temporarily put into operation as long as it is able to keep the actual return temperature above the target return temperature. The temperature sensor is used to check whether the heat pump can provide the necessary heating output and whether the actual return temperature remains above the target return temperature. If the actual return temperature is determined to be below the target return temperature, a time relay is used to give the heat pump the opportunity to raise the actual return temperature above the target return temperature for a predefined period of time, for example three to five minutes. If the heat pump does not manage to do this within this predefined period of time, the time relay switches the heat pump off and the boiler burner on for a specific period of time. This specific burner run time is set using a timer.

The control and/or regulation of the heat pump and the boiler described here is not yet optimal. Due to the specified time period of three to five minutes for operating the heat pump after the actual return temperature falls below the target return temperature, on the one hand it cannot be guaranteed that the actual return temperature will be raised above the target return temperature again, but on the other hand it is also conceivable that the actual return temperature will be raised too much, which is accompanied by an increased energy requirement. An analogous problem occurs during the subsequent operation of the boiler, which is operated for a certain period of time if the actual return temperature is not raised above the target return temperature by the heat pump within the specified time. The control and/or regulation described here is also due to The necessary time relays involve relatively high equipment expenditure and a high control effort.

DE 32 30 940 A1 shows another central heating system with a primary heat source designed as a boiler, a heat pump and a domestic hot water storage tank for domestic hot water heating, with each of these units being assigned a pump and a heating circuit. A heat transfer fluid can be fed to the heat pump via a heat pump inflow line, also called a return line, from, for example, an underfloor heating system. Several valves are provided so that different operating modes of the central heating system can be implemented using the boiler and the heat pump. The domestic hot water storage tank or the underfloor heating can be operated or heated using the heat pump alone. The domestic hot water storage tank or the underfloor heating can also be operated or heated using the boiler alone. It is also possible to operate the heat pump and boiler simultaneously in order to supply the underfloor heating with the appropriately heated heat transfer fluid using the heat pump and the boiler, with the heat transfer fluid heated by the heat pump then being supplied to the boiler. The heat pump and boiler are therefore connected in series in terms of flow using the valves. For economic reasons, the heat pump is not operated at outside temperatures below 5°C. 30-50% of the heat requirement can be generated using the heat pump. A ready-to-install coupling unit, i.e. a hydraulic module, is provided in which all the connection connections or connections for connecting the heating boiler to the heat pump and the associated heating circuits are arranged. The hydraulic module is either delivered fully connected and located directly on the back of the heating boiler, or the hydraulic module is delivered as a fully installed hydraulic module, which is then connected as a whole to the corresponding connections on the heating boiler.

In particular, the heating of the domestic water in the domestic water storage tank is not yet optimally designed. Simultaneous heating of the domestic water by the heat transfer fluid using the heat pump and the boiler is not possible using the valves and heating circuits described. This means that the domestic water is heated early on using fuels from the boiler alone, particularly since the heat pump is only designed for 30-50% of the heat requirement, so that the fuel requirement increases over the year or is correspondingly high. The invention is therefore based on the object of designing and/or further developing the central heating system or the method for operating and/or controlling and/or regulating the central heating system in such a way that in particular the necessary fuel requirement for the primary energy source is reduced over the year, in particular the design and/or control technology effort is reduced, and in particular the associated costs are also reduced.

This problem underlying the invention is now initially solved - for the central heating system - with the features of patent claim 1.

One aspect of the invention essentially lies in the fact that a temperature sensor is arranged in a - viewed vertically - lower area of the domestic water tank or adjacent to this - viewed vertically - lower area of the domestic water tank for determining the actual domestic water temperature. A further aspect of the invention is that the temperature sensor is connected to a heat pump control and/or regulating device in terms of control/signal/and/or data technology. A further aspect of the invention is that the heat pump is connected to the heat pump control and/or regulating device in terms of control technology. A further aspect of the invention is that the heat pump control and/or regulating device is designed and/or constructed in such a way that the heat pump can be controlled and/or regulated depending on the determined actual domestic water temperature.

In this way, the temperature of the domestic water can be controlled and/or regulated particularly well by means of the heat pump and the heat pump control and/or regulation device. By arranging the temperature sensor in the - viewed vertically - lower area of the domestic water tank, the heat pump can initially be controlled and/or regulated particularly quickly, in particular without a large time delay, especially when fresh and therefore cold or colder domestic water is fed back into the domestic water tank due to the removal of domestic water from the domestic water tank (e.g. for a domestic shower) by filling the domestic water tank with fresh domestic water. The - fresh - domestic water fed in flows around the temperature sensor before it mixes with the rest of the domestic water still present in the domestic water tank, some of which has already been heated. The - viewed vertically - lower area of the domestic water tank is formed or preferably forms in a lower third, in particular in a lower quarter, of the entire height of the domestic water tank. With regard to the term “domestic water storage tank”, it should be noted that this refers in particular to a water storage tank in which the water is heated. The “domestic water storage tank” can therefore also be referred to as a “hot water storage tank”. The heated water is/can then be taken from the domestic water storage tank, for example for a domestic shower or for domestic cooking or washing up, with new fresh water then being fed into the domestic water storage tank to refill it. The designation of this storage tank as a “domestic water storage tank” does not mean that already used/used and/or dirty water is stored in this tank, but rather that the water stored and/or saved here is used for subsequent “use”, for example for showering. In particular, drinking water is therefore stored, saved and heated in the domestic water storage tank. This should be noted.

In a preferred embodiment of the central heating system, the temperature sensor is arranged in or on a part of a domestic water inflow line formed between an inflow valve and an inflow connection of the domestic water storage tank, in particular by means of a T-piece.

By opening the inflow valve, fresh domestic water, especially drinking water, can be fed to the domestic water tank via the domestic water inflow line and the inflow connection. Up to the inflow valve (viewed from the domestic water tank), the domestic water inflow line is functionally assigned to the condensate tank, since the domestic water temperatures here are comparable to those at the same level within the domestic water tank. The temperature sensor can also be installed on the domestic water inflow line without great effort in terms of construction, since the domestic water tank itself does not have to be structurally modified and the temperature sensor can still be installed, especially with direct contact with the freshly supplied domestic water. In particular, a section of the domestic water inflow line can also be cut out and replaced in particular with a T-piece, in which case the temperature sensor is arranged in a branch of the T-piece and is preferably connected to the T-piece with a closure cap. On the other hand, the T-piece could also be interposed in the domestic water supply line in such a way that a part of the domestic water supply line is connected to the branch of the T-piece, so that the temperature sensor is also arranged on one of the two parallel connections of the T-piece and closes this connection and the The temperature sensor then preferably penetrates the T-piece completely. It is also conceivable and possible to arrange the temperature sensor on the outside or in a housing/jacket area of the domestic water storage tank or the domestic water supply line.

The aforementioned temperature sensor is preferably designed as a first temperature sensor for determining a first actual domestic water temperature, with a second temperature sensor being arranged in a middle or upper area of the domestic water tank - viewed vertically - for measuring a second, preferably average actual domestic water temperature. The second temperature sensor is connected to the central heating control and/or regulating device in terms of control/signal/and/or data technology. The central heating control and/or regulating device is designed and/or constructed in such a way that the primary heat source can be controlled and/or regulated depending on the second actual domestic water temperature. In general, it should also be pointed out at this point that the term "connected in terms of control technology" used here and elsewhere can and does always include a signal and/or data connection.

The middle or upper area of the domestic hot water tank - viewed vertically - is preferably formed in the upper two thirds, in particular in the upper half, of the entire height of the domestic hot water tank or is then formed accordingly there. The central heating control and/or regulating device and the heat pump control and/or regulating device are preferably designed separately from one another so that they do not directly influence one another and the controls and/or regulations carried out by means of the central heating control and/or regulating device and those carried out by means of the heat pump control and/or regulating device are independent of one another. This is particularly advantageous if the heat pump control and/or regulating device including the heat pump are subsequently integrated into the central heating system, since the central heating control and/or regulating device then does not have to be changed. On the other hand, it is also conceivable that the central heating control and/or regulating device and the heat pump control and/or regulating device are or will be combined in a common control and/or regulating device, which is advantageous if the entire central heating system is designed at the same time.

An optimal control and/or regulation of the entire central heating system, especially with regard to a minimized need for fuel for the Primary energy source and/or avoiding cost-intensive structural designs is therefore made possible in particular by the specific arrangement of the first temperature sensor relative to the second temperature sensor. The first temperature sensor is arranged - essentially viewed in the vertical direction - below the second temperature sensor, whereby due to a temperature stratification of the domestic water forming within the domestic water tank, not only can a lower actual domestic water temperature be determined using the first temperature sensor than using the second temperature sensor, but a change in the temperature, in particular a decrease in the temperature, can be determined earlier in time using the first temperature sensor than using the second temperature sensor. This also forms the basis, in particular, for optimally controlling the heat pump, in particular preferentially operating it, even in the case of an independently designed central heating control and/or regulating device or a heat pump control and/or regulating device, and for activating and/or operating the primary heat source only when the power or amount of heat provided by the heat pump is no longer sufficient, in particular to cover the need to heat the domestic hot water tank, so that the need for fuel for the primary heat source can thus be minimized or at least reduced.

In a further embodiment of the central heating system, the heat pump control and/or regulating device is designed and/or constructed such that the heat pump can be operated and/or activated with the aid of the heat pump control and/or regulating device to heat the heat transfer fluid when the first actual domestic water temperature measured, determined and/or calculated, in particular by the heat pump control and/or regulating device, with the aid of the first temperature sensor falls below a first limit temperature.

The central heating control and/or regulating device is designed and/or constructed such that the primary heat source can be operated and/or activated with the aid of the central heating control and/or regulating device to heat the heat transfer fluid when the second actual domestic water temperature measured, determined and/or calculated with the aid of the second temperature sensor falls below a second limit temperature.

By introducing the first and second limit temperatures, the heat pump can be operated preferentially in a particularly simple manner. To do this, the first and second limit temperatures are selected accordingly or set to a specific limit temperature. For example, the first limit temperature is lower than the second Limit temperature. On the other hand, the second limit temperature could also be lower than the first limit temperature, in which case the second limit temperature is in particular 43°C, in particular in the range from 41°C to 45°C, in which case the first limit temperature is in particular 48°C and in particular in the range from 46°C to 50°C. In particular, by appropriately selecting the respective limit temperatures, an indirect dependency of these two control and/or regulating devices on one another is achieved or realized between the central heating control and/or regulating device, which preferably operates or functions independently of one another, and the heat pump control and/or regulating device, or it can thereby also be selected and/or determined, for example, from when the primary heat source is connected to the heat pump or additionally activated.

In a preferred embodiment of the central heating system, the output of the heat pump is continuously adjustable, in particular between 0 kW and 25 kW, in particular between 1.5 kW and 7 kW, by means of the heat pump control and/or regulating device, in particular an inverter of the heat pump control and/or regulating device.

In this way, the heat pump can usually always provide exactly the amount of heat required for the entire central heating system, which has a very positive overall effect on the control and/or regulation of the central heating system. This means that a heat pump with a high maximum output can also be used sensibly, i.e. even if there is only a small heat requirement, the heat pump can provide this heat requirement and heat losses can be kept to a minimum. In the state of the art known to date, however, often only heat pumps were available that could either not be operated at all or only at maximum output, which then led to the heat pump being used less often. In order to enable the heat pump to be used more frequently, heat pumps with a lower output were used, for example. In addition to the performance ranges mentioned, it is also possible to use heat pumps with a maximum output of up to 1000kW or more, e.g. to supply heat to correspondingly large buildings such as residential or office complexes and their domestic water storage tanks.

In a preferred embodiment of the central heating system, the heat exchanger and the heat pump are fluidically connected in series with respect to the primary heat source and/or can be connected in series, which will be explained in more detail below. Preferably, an output connection of the heat pump is fluidically connected to an input connection of the primary heat source. The aforementioned fluidic series connection allows the entire heat transfer fluid heated by the heat pump to be fed to the primary heat source. This further reduces the fuel requirement of the primary heat source, since the primary heat source does not need to be activated and/or operated at all or only rarely due to the heat transfer fluid fed to the primary heat source at a relatively high temperature. Nevertheless, a desired target heat transfer fluid temperature specified within or in the area of the primary heat source can be achieved or implemented by heating the heat transfer fluid using the heat pump, which will be explained in more detail below.

Preferably, a heat exchanger inflow line of the line system is fluidically connected on the one hand to the primary heat source and on the other hand to the heat exchanger and/or connected accordingly in order to supply the heat transfer fluid to the heat exchanger by means of the heating pump through the heat exchanger inflow line. A heat pump inflow line of the line system is fluidically connected on the one hand to the heat exchanger and on the other hand to the heat pump and/or connected accordingly in order to supply the heat transfer fluid to the heat pump through the heat pump inflow line. A heat pump outflow line of the line system is fluidly connected on the one hand to the heat pump and on the other hand to the primary heat source and/or connected accordingly in order to supply the heat transfer fluid to the primary heat source through the heat pump outflow line.

Using the lines mentioned, the fluidic series connection of heat exchanger, heat pump and primary heat source can be implemented particularly easily. The lines described here can be formed easily and inexpensively using pipes and/or hoses and/or flow channels formed in housings.

In a further advantageous embodiment of the central heating system, the piping system has at least one valve, by means of which the heat transfer fluid can be directed and/or guided either from the primary heat source to the heat exchanger or past the heat exchanger to the heat pump.

Depending on the valve position, two different heating circuits can be implemented using the valve. In a first heating circuit, a flow of the heat transfer fluid from the primary heat source, via the valve, via the heating pump, via the heat exchanger, via the heat pump, via the circulation pump and back to the primary heat source. In a second heating circuit, a flow of the heat transfer fluid from the primary heat source, via the valve, via the heat pump, via the circulation pump and back to the primary heat source can be realized. In a third heating circuit, a flow of the heat transfer fluid from the primary heat source, via the or to the domestic hot water storage tank, via the storage pump and back to the primary heat source can then be generated or realized. In the primary heat source, there is preferably a distribution system for the heat transfer fluid, in particular flow channels through which the heat transfer fluid can flow are provided, to which the heating circuits are respectively connected. The heat exchanger inflow line and the heat pump outflow line, as well as a line leading to the domestic hot water storage tank and a line returning from the domestic hot water storage tank are connected to the primary heat source, in particular to such a distribution system, or are fluidically connected to the primary heat source, in particular a heating boiler.

The line system further preferably has two 3/2-way valves, each with three connections and two switching positions, namely a first 3/2-way valve, in particular arranged in the heat exchanger inflow line or interposed here, and a second 3/2-way valve, in particular arranged in the heat pump inflow line or interposed here. The first 3/2-way valve is fluidically connected to the primary heat source, the heat exchanger and the second 3/2-way valve or connected accordingly. The second 3/2-way valve is fluidically connected to the heat exchanger, the first 3/2-way valve and the heat pump or connected accordingly. The first 3/2-way valve enables the heat transfer fluid to flow optionally from the primary heat source to the heat exchanger or to the second 3/2-way valve. The second 3/2-way valve enables the heat transfer fluid to flow either from the heat exchanger or from the first 3/2-way valve to the heat pump.

The heating circuits described above can also be implemented using these two 3/2-way valves. The two 3/2-way valves are also inexpensive to purchase and easy to control and/or regulate. The two 3/2-way valves can preferably be switched from a basic position to a switching position by means of an electric actuator against a spring force applied by a mechanical spring when the actuator is energized. The two 3/2-way valves are then installed in such a way that during operation of the Central heating system, the two 3/2-way valves do not need to be energized for a longer period of time, so that energy is saved accordingly.

Advantageously, at least two elements and/or components and respective associated connections from the group of the heat exchanger inflow line at least in sections, the heat pump inflow line at least in sections, the heat pump outflow line at least in sections, the circulation pump and the valve, in particular the first 3/2-way valve and the second 3/2-way valve, are arranged and/or formed on a hydraulic module forming a common structural unit.

Using such a hydraulic module, the assembly and/or construction of the central heating system can be made much easier. Complex assembly can be avoided because the design of the hydraulic module predetermines certain arrangements of elements and/or components in relation to one another or makes them simple and easy for the fitter to recognize. The hydraulic module can then advantageously be pre-assembled, for example, in a factory or at a heating engineer's, so that the assembly time for an end customer who operates the central heating system can be greatly reduced.

In a preferred, alternative embodiment of the central heating system, the heat exchanger and the heat pump are connected in parallel in terms of flow with respect to the primary heat source or can be connected in parallel, which will also be explained below.

Such a parallel connection has the particular advantage that no valves are required to optionally supply the heat exchanger and/or the heat pump with heat transfer fluid from the primary heat source or to direct the heat transfer fluid accordingly. Only the heating pump and the circulation pump need to be controlled accordingly. In parallel connection, slightly modified first and second heating circuits are then obtained - in comparison to series connection - with the third heating circuit remaining essentially unchanged. In the first heating circuit, a flow of the heat transfer fluid from the primary heat source, via the heating pump, via the heat exchanger and back to the primary heat source can then be realized. In the second heating circuit, a flow of the heat transfer fluid from the primary heat source, via the heat pump, via the circulation pump and back to the primary heat source can then be realized. A third heating circuit is also realized corresponding to the embodiment shown in Fig. 1. Preferably, a heat exchanger inflow line of the piping system is then fluidically connected on the one hand to the primary heat source and on the other hand to the heat exchanger or is connected accordingly in order to supply the heat transfer fluid to the heat exchanger by means of the heating pump through the heat exchanger inflow line. A heat exchanger outflow line of the piping system is fluidically connected on the one hand to the heat exchanger and on the other hand to the primary heat source or is connected accordingly in order to return the heat transfer fluid to the primary heat source by means of the heating pump through the heat exchanger outflow line. A heat pump inflow line of the piping system is fluidly connected on the one hand to the heat exchanger inflow line and on the other hand to the heat pump or is connected accordingly in order to supply the heat transfer fluid to the heat pump by means of the circulation pump through the heat pump inflow line. A heat pump drain line of the piping system is fluidically connected on the one hand to the heat pump and on the other hand to the heat exchanger drain line or is connected accordingly in order to supply the heat transfer fluid to the primary heat source by means of the circulation pump through the heat pump drain line and in particular a part of the heat exchanger drain line. However, it would also be conceivable that in order to implement the parallel connection described, the heat pump inlet line and the heat pump drain line are fluidically connected directly to the primary heat source; this should also be noted.

By means of the lines mentioned, the fluidic parallel connection of heat exchanger and heat pump to the primary heat source can be implemented particularly easily.

A check valve is preferably integrated or arranged and/or interposed between the heat exchanger and a connecting piece arranged and/or formed between the heat exchanger discharge line and the heat pump discharge line in the heat exchanger discharge line in order to prevent a backflow of the heat transfer fluid from the heat pump to the heat exchanger via the heat exchanger discharge line. A backflow could lead to undefined flow conditions, which could disrupt the control and/or regulation of the heat pump and primary heat source as well as the pumps. Avoiding the backflow thus leads to an improvement in the control and/or regulation of the central heating system. Another connecting piece is preferably arranged between the heat exchanger inflow line and the heat pump. Inflow line is arranged and/or designed. The first and second heating circuits are then designed accordingly with the help of the connecting pieces when connected in parallel.

Further preferably, the heat pump control and/or regulating device is connected to the central heating control and/or regulating device for supplying energy to the heat pump control and/or regulating device and/or the heat pump control and/or regulating device is connected to the heating pump for control and/or regulating the heating pump and/or the heat pump control and/or regulating device is connected to the circulation pump for control and/or regulating the circulation pump and/or the heat pump control and/or regulating device is connected to the storage pump for control and/or regulating the storage pump and/or the heat pump control and/or regulating device is connected to an outside temperature sensor for determining an outside temperature for control/signal/and/or data purposes. The above applies in particular to a series and a parallel connection of the heat exchanger and the heat pump. In particular, the heat pump control and/or regulating device is also connected in terms of control technology to the at least one valve, in particular also to the two 3/2-way valves, in particular in order to control and/or switch these valves as well.

This means that essential elements and/or components of the central heating system can be controlled and/or regulated using the heat pump control and/or regulating device. These elements and/or components can then also be controlled and/or regulated themselves depending on the respective output of the heat pump. This takes into account in particular the fact that the heat pump can be operated primarily as a primary heat source and the primary heat source can only be activated and/or operated if the heat provided by the heat pump is no longer sufficient in a particular application to cover the heat requirements of the central heating system, in particular the heat requirements of the heat exchanger and/or the domestic hot water tank. The energy supply to the heat pump control and/or regulating device could then also be provided directly via a power grid, for example; this should also be noted.

The object underlying the invention is also achieved by a method for operating and/or controlling and/or regulating a central heating system with the features of patent claim 16. One aspect of the invention is then essentially that an actual domestic water temperature in a - viewed vertically - lower area of the domestic water storage tank is measured, determined and/or calculated, in particular by a heat pump control and/or regulating device, with the aid of a temperature sensor. A further aspect of the invention is then that the heat pump is controlled and/or regulated by means of a heat pump control and/or regulating device depending on the determined actual domestic water temperature.

In this way, the temperature of the domestic water is controlled and/or regulated particularly well by means of the heat pump and the heat pump control and/or regulation device. By arranging the temperature sensor in the - vertically viewed - lower area of the domestic water tank, the heat pump is controlled and/or regulated particularly quickly, in particular without a long time delay when fresh and therefore particularly cold domestic water is then fed back into the domestic water tank due to domestic water being withdrawn from the domestic water tank, for example for a shower, in particular because the domestic water fed in flows around the temperature sensor before it mixes with the rest of the domestic water still present in the domestic water tank.

The temperature sensor is preferably designed as a first temperature sensor for measuring and/or determining a first actual domestic water temperature. The first actual domestic water temperature is transmitted to a heat pump control and/or regulating device and/or determined and/or calculated by means of the heat pump control and/or regulating device. A second, preferably average, actual domestic water temperature is measured, determined and/or calculated by means of a second temperature sensor in a - viewed vertically - middle or upper area of the domestic water storage tank. The second actual domestic water temperature is transmitted to the central heating control and/or regulating device and/or determined and/or calculated by means of the central heating control and/or regulating device. The primary heat source is controlled and/or regulated by means of the central heating control and/or regulating device depending on the second actual domestic water temperature.

An optimal control and/or regulation of the entire central heating system is carried out or realized with regard to a minimized need for fuel for the primary heat source through the specific arrangement of the two temperature sensors. Due to the fact that the first temperature sensor is used due to the temperature stratification of the domestic water If a lower actual domestic water temperature is determined in the domestic water storage tank than by means of the second temperature sensor, the entire central heating system can be optimally controlled, even with central heating control and/or regulating devices or heat pump control and/or regulating devices that are designed independently of one another, with the heat pump being operated in particular preferably before the primary heat source. In this way, the need for fuel for the primary heat source can be minimized or reduced.

According to a particularly preferred embodiment of the method, the heat pump can be operated and/or activated with the aid of the heat pump control and/or regulating device to heat the heat transfer fluid, in particular when the first actual domestic water temperature measured, determined and/or calculated with the aid of the first temperature sensor falls below a first limit temperature. The primary heat source can be operated and/or activated with the aid of the central heating control and/or regulating device to heat the heat transfer fluid, in particular when the second actual domestic water temperature measured, determined and/or calculated with the aid of the second temperature sensor falls below a second limit temperature.

By introducing the first and second limit temperatures, the heat pump is preferentially operated in a particularly simple manner, whereby in particular the first and second limit temperatures are selected accordingly.

The first and the second limit temperature are further preferably selected such that the primary heat source is only operated and/or activated with the aid of the central heating control and/or regulating device for heating the heat transfer fluid when a heat requirement of the domestic hot water storage tank exceeds a quantity of heat that can be provided by the heat pump at maximum output of the heat pump or - to put it another way - the output of the heat pump alone is no longer sufficient to heat the domestic hot water to the desired temperature.

In this way, the performance of the heat pump is optimally utilized and the primary energy requirement for the primary heat source, namely the fuel requirement, of the central heating system is further reduced. The heat requirement of the domestic hot water storage tank is preferably determined indirectly by selecting the limit temperatures in relation to other relevant parameters such as the size of the domestic hot water storage tank. Preferably, when the domestic water storage tank is in operation, a vertical temperature stratification of the domestic water in the domestic water storage tank is established. The first actual domestic water temperature is measured in a lower, first temperature layer. The second actual domestic water temperature is measured in a middle or upper, second temperature layer. The first temperature layer forms vertically below the second temperature layer.

Central heating systems use domestic water storage tanks which have a particularly pronounced temperature stratification. For example, viewed vertically, the lowest temperature layer, which is in particular the first temperature layer, has a temperature of around 30°C. The top temperature layer then has a temperature of around 45°C, for example. The middle or upper, second temperature layer then has a temperature of around 40°C, for example. It would also be conceivable to operate the domestic water storage tank at higher temperatures, with the lowest temperature layer, which is in particular the first temperature layer, having a temperature of around 50°C, with the top temperature layer then having a temperature of around 60°C, for example, and the middle or upper, second temperature layer then having a temperature of around 56°C, for example.

The heating pump is advantageously controlled and/or regulated by the heat pump control and/or regulation device, in particular depending on an outside temperature measured by an outside temperature sensor. The building can thus be heated accordingly by means of the heat exchanger, in particular the heater or radiator, in particular with the help of several heaters, depending on the outside temperature. In winter, when outside temperatures are low, the building is heated more by the central heating system than in summer, which is accompanied by correspondingly high flow rates from the heating pump, which can drop to zero in summer in particular.

According to a further preferred embodiment of the method, the heating pump is switched off by means of the heat pump control and/or regulating device when the storage pump is operated and/or activated by means of the heat pump control and/or regulating device. This is particularly the case when the domestic water in the domestic water storage tank has to be heated due to the withdrawal of domestic water from the domestic water storage tank, for example for a shower, and when the domestic water storage tank is refilled with new domestic water (e.g. drinking water). It can also be said that the central heating system is used to heat either the building or the domestic water. This is advantageous because in this way the maximum output of the central heating system can be set somewhat lower than if the building and the domestic water were to be heated at the same time. During the times when the domestic water is being heated, the temperature of the building only drops very slightly if the residents of the building use it normally, so that only minor or imperceptible losses in comfort are to be expected from the "brief" shutdown of the heating pump. However, it is also conceivable that the building and the domestic water can be heated at the same time, which is also referred to as "parallel" operation of the central heating system. In this "parallel" operation, the heating pump and the storage pump in particular are then operated simultaneously.

Preferably, the heat pump and/or the circulation pump are controlled and/or regulated by means of the heat pump control and/or regulating device as a function of a first actual heat transfer fluid temperature formed at the outlet of the heat pump and/or as a function of a first target heat transfer fluid temperature predetermined for the outlet of the heat pump.

The heat pump has an internal fluid circuit through which a coolant flows, which evaporates at low pressure while adding heat and, after being compressed to a higher pressure, condenses again while releasing heat to the heat transfer fluid. For this process, the heat pump requires an evaporator, a compressor, a condenser and a throttle. The gaseous coolant is compressed in the compressor and in particular heats up in the process. The hot, compressed coolant then gives off its heat to the heat transfer fluid in the condenser. The compressed coolant cools down and in particular condenses at least partially to liquid coolant. When it then flows through the throttle, the coolant is expanded and in particular partially cooled further. The then cold coolant then flows through the evaporator - usually located outside the building. In the evaporator, the cold coolant is heated by groundwater or the outside air, for example, and evaporates in the process. The coolant is then fed back to the compressor and the process begins again. Preferably, the heat pump is designed as an air-water heat pump, in which the coolant in the evaporator is heated by means of the outside air. Further preferably, the evaporator, the compressor, the condenser and the throttle are designed as a common structural unit, wherein the heat pump inlet line and the Heat pump drain line is particularly connected to the heat pump condenser.

According to a particularly preferred embodiment of the method, the primary heat source is controlled and/or regulated by means of the central heating control and/or regulating device as a function of a second actual heat transfer fluid temperature - which forms within or in the region of the primary heat source - and/or a second target heat transfer fluid temperature - predetermined for the primary heat source.

This represents a simple way of controlling and/or regulating the primary heat source using the central heating control and/or regulating device. It is conceivable that a further temperature sensor is arranged inside or in the area of the primary heat source to determine the second actual heat transfer fluid temperature. Alternatively, it is even conceivable that the second actual heat transfer fluid temperature is determined, in particular calculated, using physical models stored in the central heating control and/or regulating device.

It can be very advantageous if the second target heat transfer fluid temperature is below the first target heat transfer fluid temperature or is set accordingly, so that the primary heat source is only operated and/or activated with the aid of the central heating control and/or regulating device for heating the heat transfer fluid when a heat requirement of the central heating system, in particular a heat requirement of the heat exchanger and/or the domestic hot water storage tank, exceeds an amount of heat that can be provided by the heat pump at maximum output of the heat pump.

The heat pump can therefore be operated as a primary heat source even when the domestic water in the domestic water storage tank is not being heated by the heat transfer fluid and the heat transfer fluid is not being pumped through the third heating circuit by the storage pump. Overall, in particular over the course of the year, the fuel requirement of the central heating system can thus be further reduced. The heat requirement of the central heating system, in particular of the heat exchanger and/or the domestic water storage tank, is preferably determined indirectly, in particular by selecting/setting the two target heat transfer fluid temperatures. Such a heat requirement of the heat exchanger is also dependent in particular on a desired room temperature of a room to be heated with the heat exchanger. It is It is conceivable that such a desired room temperature is selected by a user of the room to be heated and is then available in the heat pump control and/or regulation device for controlling and/or regulating the heat pump. One could also say that the first target heat transfer fluid temperature is then dependent on the desired room temperature. If the heat pump is controlled and/or regulated based on the desired room temperature, this is also referred to as modulating operation of the heat pump.

Preferably, the first target heat transfer fluid temperature and/or the first limit temperature are determined by means of a table and/or formula stored in the heat pump control and/or regulating device, in particular the first target heat transfer fluid temperature is also determined as a function of an outside temperature measured and/or determined by means of the outside temperature sensor and/or calculated as a function of a desired room temperature. In particular, the first target heat transfer fluid temperature is 55°C to 65°C, in particular 59°C to 61°C.

The central heating system is thus optimized for lower heat requirements at higher outside temperatures, namely by the first target heat transfer fluid temperature having lower values at higher outside temperatures. By using lower values for the first target heat transfer fluid temperature and/or the first limit temperature, operation of the primary heat source can be reduced or the efficiency of the entire system can be increased. The dependence of the first target heat transfer fluid temperature on the outside temperature is also referred to as the heating curve. The first target heat transfer fluid temperature can also be referred to as the target flow temperature. In particular, the first target heat transfer fluid temperature depends on both the outside temperature and the desired room temperature.

According to a further embodiment of the method, the second target heat transfer fluid temperature and/or the second limit temperature is determined by means of a table and/or formula stored in the central heating control and/or regulating device, in particular the second target heat transfer fluid temperature is also determined as a function of an outside temperature measured and/or determined by means of a preferably further outside temperature sensor and/or is calculated as a function of a desired room temperature. In particular, the second target heat transfer fluid temperature is 51°C to 53°C at an outside temperature between -1°C and +1°C. Thus, the central heating system is optimized in terms of its energy requirements, especially its fuel requirements.

To simplify the method, in particular the first and/or the second limit temperature are stored as constant values in the heat pump control and/or regulating device and/or in the central heating control and/or regulating device, so that the first and the second limit temperature are independent of the outside temperature. The first limit temperature is in particular set in the heat pump control and/or regulating device or is stored here, wherein in particular the second limit temperature is stored and/or set in the central heating control and/or regulating device.

There are now a number of possibilities for designing and developing the central heating system according to the invention and the method according to the invention for operating and/or controlling and/or regulating a central heating system in an advantageous manner. Reference may first be made to the claims subordinate to claim 1 and to the claims subordinate to claim 16. A preferred embodiment of the central heating system according to the invention and the method according to the invention for operating and/or controlling and/or regulating the central heating system is now explained or described in more detail below with reference to the following drawing and the associated description below. The drawing shows:

Fig.1 shows a schematic representation of a hydraulic circuit diagram of a first embodiment of the central heating system,

Fig.2a shows a schematic representation of a domestic water storage tank for use in the central heating system in an enlarged side view,

Fig.2b shows a schematic representation of the domestic hot water storage tank for use in the central heating system in an enlarged side view with a different temperature stratification compared to Fig.2a,

Fig.3 shows a schematic representation of a hydraulic circuit diagram of a second embodiment of the central heating system, Fig.4 shows a schematic flow chart for a method for operating and/or controlling and/or regulating a heat pump of the central heating system according to Fig.1 or Fig.3,

Fig.5 shows a schematic flow chart for a method for operating and/or controlling and/or regulating a primary heat source of the central heating system according to Fig.1 or Fig.3,

Fig.6a shows a schematic representation of a dependency of a first target heat transfer fluid temperature, a first limit temperature, a second target heat transfer fluid temperature or a second limit temperature on the outside temperature, wherein the first limit temperature is lower than the second limit temperature, and

Fig.6b shows a schematic representation of a dependency of a first target

Heat transfer fluid temperature, a first limit temperature, a second target heat transfer fluid temperature or a second limit temperature to the outside temperature, wherein the first limit temperature is greater than the second limit temperature.

The central heating system 1 shown in Fig. 1 and 3 has at least one primary heat source 2 that can be operated with the aid of fuels, in particular a heating boiler and/or a gas boiler, at least one electrically operated heat pump 3, at least one heat exchanger 4, preferably a heating element or a radiator for heating a building, and at least one domestic water storage tank 5. The heat exchanger 4 could also be designed by means of or as an underfloor heating system. It should also be pointed out here that the terms "primary heat source 2 that can be operated with fuels" or "heating boiler" include in particular an oil boiler that can be operated with oil or a gas boiler that can be operated with gas.

A heat transfer fluid 6, in particular water, can be heated by means of the primary heat source 2 and/or with the aid of the heat pump 3. The heat transfer fluid 6, in particular previously heated, can be conveyed through the heat exchanger 4 by means of a pipe system 7 and by means of a heating pump 8.

By means of the pipe system 7, in particular with the aid of a circulation pump 9, the heat transfer fluid 6 can be conveyed for heating by the heat pump 3. By means of the pipe system 7 and a storage pump 10, the heat transfer fluid 6 can be conveyed to the domestic water storage tank 5 for heating domestic water 11 temporarily stored in the domestic water storage tank 5, in particular for heat transfer from the heat transfer fluid 6 to the domestic water 11 through or adjacent to the domestic water storage tank 5.

Such a domestic water storage tank 5, which can be used both in the first embodiment of the central heating system according to Fig. 1 and in the second embodiment of the central heating system 1 according to Fig. 3, is shown schematically enlarged in Fig. 2a and Fig. 2b. The heat transfer from the heat transfer fluid 6 to the domestic water 11 takes place here in particular by means of a line running helically through the domestic water storage tank 5, through which the heat transfer fluid 6 can be passed. The line could also run in a different way, e.g. in an arc through the domestic water storage tank 5. The heat transfer fluid 6 can preferably be fed to an upper end of the line running helically through the domestic water storage tank 5 and can be discharged again from the domestic water storage tank 5 from a lower end of the line running helically through the domestic water storage tank 5. Alternatively, it is conceivable that a line, preferably running in a meandering shape, is arranged and/or formed in a wall of the domestic water storage tank 5 in order to enable the heat transfer from the heat transfer fluid 6 to the domestic water 11 by flowing through this line by means of the heat transfer fluid 6. Furthermore, lines for this heat transfer could be arranged on the outside of the wall of the domestic water storage tank 5, wherein these lines are then insulated in particular on a side facing away from the domestic water storage tank 5.

The heat transfer fluid 6 can therefore be conveyed to the domestic water storage tank 5 in order to flow in particular through the aforementioned line arranged within the domestic water storage tank 5, within the wall of the domestic water storage tank 5 and/or outside on the wall of the domestic water storage tank 5, so that the heat transfer fluid 6 then flows through or adjacent to the domestic water storage tank 5 and in the process heats the domestic water 11.

The heat transfer fluid 6 can be conveyed through the primary heat source 2 by means of the heating pump 8, in particular the circulation pump 9, and/or the storage pump 10. A central heating control and/or regulating device 12 is connected to the primary heat source 2 for the purpose of controlling and/or regulating it. It is conceivable that the heat exchanger 4 and the heat pump 3 are connected in such a way, in particular in series in terms of flow, that the heat transfer fluid 6 can be pumped by means of the heating pump 8 through both the heat exchanger 4 and the heat pump 3, so that the use of the circulation pump 9 is then not absolutely necessary.

The disadvantages mentioned at the beginning are now avoided in particular as follows: A temperature sensor 13.1 is arranged in a - viewed vertically - lower area of the domestic hot water tank 5 or adjacent to this - viewed vertically - lower area of the domestic hot water tank 5 to determine the actual domestic hot water temperature TBI. The temperature sensor 13.1 is connected to a heat pump control and/or regulating device 14 for control/signal/and/or data purposes. The heat pump 3 is connected to the heat pump control and/or regulating device 14 for control purposes. The heat pump control and/or regulating device 14 is designed and/or constructed such that the heat pump 3 can be controlled and/or regulated depending on the determined actual domestic hot water temperature TBI. This avoids the disadvantages mentioned at the beginning and achieves corresponding advantages, which can also be explained again below.

The temperature sensor 13.1 could penetrate a wall of the domestic water tank 5, so that a measuring range of the temperature sensor 13.1 is arranged within the domestic water tank 5 with direct contact to the domestic water 11.

In the preferred embodiment, however, the temperature sensor 13.1 - as can be seen in Fig. 2a and Fig. 2b - is arranged in or on a part of a domestic water inflow line 17 formed between an inflow valve 15 and an inflow connection 16 of the domestic water storage tank 5, in particular by means of a T-piece 18. The measuring range of the temperature sensor 13.1 is in direct contact with the domestic water 11. The T-piece 18 is interposed in the domestic water inflow line 17 according to Fig. 2a and Fig. 2b in such a way that a part of the domestic water inflow line 17 is connected to a branch of the T-piece 18, so that the temperature sensor 13.1 is also arranged on one of the two parallel connections of the T-piece 18 and closes this connection by means of a closure cap. The temperature sensor 13.1 preferably penetrates the T-piece 18 completely and, according to Fig.2a and Fig.2b, is arranged with its measuring range inside the domestic hot water tank 5 despite the arrangement on the T-piece 18. It would also be conceivable, however, that the measuring range of the Temperature sensor 13.1 is arranged within the service water inflow line 17, in particular within the T-piece 18.

In contrast, it would also be entirely conceivable for the temperature sensor 13.1 to be arranged on the outside of the wall of the domestic water storage tank 5 or on the outside of the domestic water inflow line 17, wherein when determining the actual domestic water temperature TBI by means of the heat pump control and/or regulating device 14, a temperature gradient occurring across the wall of the domestic water storage tank 5 or across a wall of the domestic water inflow line 17 is preferably taken into account.

The arrangement of the temperature sensor 13.1 symbolized in Fig.1 and Fig.3 basically includes all variants described above.

Fluidically adjacent to the inflow valve 15, a check valve 15.r is integrated and/or arranged in the service water inflow line 17 or interposed here in order to prevent a backflow of the service water 11 from the service water storage tank 5 into the service water inflow line 17 even when the inflow valve 15 is open.

The temperature sensor 13.1 is designed as a first temperature sensor 13.1 for determining a first actual domestic water temperature TBI, with a second temperature sensor 13.2 being arranged in a - viewed vertically - middle or upper area of the domestic water tank 5 for measuring a second, preferably average actual domestic water temperature T _B 2 . The second temperature sensor 13.2 is connected to the central heating control and/or regulating device 12 for control/signal/and/or data purposes. The central heating control and/or regulating device 12 is designed and/or constructed such that the primary heat source 2 can be controlled and/or regulated depending on the second actual domestic water temperature TB2.

The two temperature sensors 13.1 and 13.2 are referred to as the first and second temperature sensors only for the sake of clear assignment. The designation first and second temperature sensors therefore does not represent a dependency on one another and is not to be viewed as restrictive. Another clear designation for the two respective temperature sensors would also be conceivable.

The second temperature sensor 13.2 could also penetrate a wall of the domestic hot water tank 5, so that a measuring range of the second temperature sensor 13.2 within the Domestic water tank 5 with direct contact to the domestic water 11. In contrast, the second temperature sensor 13.2 could also be arranged on the outside of the wall of the domestic water tank 5.

The heat pump control and/or regulating device 14 is designed and/or constructed such that the heat pump 3 can be operated and/or activated with the aid of the heat pump control and/or regulating device 14 to heat the heat transfer fluid 6 when the first actual domestic water temperature TBI measured, determined and/or calculated with the aid of the first temperature sensor 13.1, in particular by the heat pump control and/or regulating device 14, falls below a first limit temperature TBIG. The central heating control and/or regulating device 12 is designed and/or constructed such that the primary heat source 2 can be operated and/or activated with the aid of the central heating control and/or regulating device 12 to heat the heat transfer fluid 6 when the second actual domestic water temperature T _B 2 measured, determined and/or calculated with the aid of the second temperature sensor 13.2 falls below a second limit temperature T _B2 G.

In principle, the control and/or regulation of the heat pump 3 and the primary heat source 2 takes place independently of one another, which means in particular that no parameters and/or measured values for the control of the primary heat source 2, such as a level of fuel supply, are then available in the heat pump control and/or regulation device 14. On the other hand, in particular no operating data and/or parameters of the heat pump 3 are available in the central heating control and/or regulation device 12. The control of the primary heat source 2 takes place, in particular exclusively with the aid of the central heating control and/or regulation device 12, with the control of the heat pump taking place, in particular exclusively with the aid of the heat pump control and/or regulation device 14. A particularly indirect dependency between the control and/or regulation of the heat pump 3 and the primary heat source 2 arises in particular only through the selection of the two limit temperatures TBIG, T _B2 G in relation to one another and through the specific arrangement of the associated two temperature sensors 13.1, 13.2 in relation to one another.

For example, the first limit temperature T _B I _G is smaller than the second limit temperature T _B2 G-

On the other hand, the second limit temperature T _B2G could also be lower than the first limit temperature T _B I _G , in which case the second limit temperature T _B2G could be in particular 43°C is, in particular in the range from 41 °C to 45°C, whereby the first limit temperature TBIG is then in particular 48°C and in particular in the range from 46°C to 50°C. In this case, the second limit temperature T _B 2G can then be set in particular 3°C to 7°C, in particular 5°C lower than the first limit temperature TBIG-

An output of the heat pump 3 can be continuously adjusted by means of the heat pump control and/or regulating device 14, in particular an inverter 19 of the heat pump control and/or regulating device 14, in particular between 0 kW and 25 kW, in particular between 1.5 kW and 7 kW.

The maximum output of the primary heat source 2 is, for example, 17 kW, whereby the output of the primary heat source 2 is preferably also continuously adjustable. For example, a primary heat source 2 with a maximum output of 15 kW is used in combination with a heat pump 3 with a maximum output of 7 kW, so that a maximum of 22 kW is available by means of the central heating system 1 when the primary heat source 2 and the heat pump 3 are operating simultaneously, which is also sufficient to supply typical residential buildings with heat.

In the first embodiment of the central heating system 1 according to Fig.1, the heat exchanger 4 and the heat pump 3 are fluidically connected in series with respect to the primary heat source 2 or can be connected in series.

For this purpose, a heat exchanger inflow line LWT, _ZU of the line system 7 is fluidically connected on the one hand to the primary heat source 2 and on the other hand to the heat exchanger 4 or is connected accordingly in order to supply the heat transfer fluid 6 to the heat exchanger 4 by means of the heating pump 8 through the heat exchanger inflow line LWT, _ZU . A heat pump inflow line LWP, _ZU of the line system 7 is further fluidically connected on the one hand to the heat exchanger 4 and on the other hand to the heat pump 3 or is connected accordingly in order to supply the heat transfer fluid 6 to the heat pump 3 through the heat pump inflow line LWP, _ZU . And a heat pump outflow line LWP, ab of the line system 7 is fluidically connected on the one hand to the heat pump 3 and on the other hand to the primary heat source 2 or is connected accordingly in order to supply the heat transfer fluid 6 to the primary heat source 2 through the heat pump outflow line LWP. Thus, the heat transfer fluid 6 preheated by means of the heat pump 3 can be completely supplied to the primary heat source 2.

According to Fig.1, the line system 7 has at least one valve 20, with the aid of which the heat transfer fluid 6 can be directed and/or guided either from the primary heat source 2 to the heat exchanger 4 or past the heat exchanger 4 to the heat pump 3. The valve 20 is initially shown in Fig.1 as a single valve 20 with dashed lines, but in particular in the very preferred embodiment, which is described in more detail below, two 3/2-way valves 21.1, 21.2 can be used or are present accordingly.

The line system 7 therefore has in particular (as an alternative to a single, in particular complexly designed valve 20) two 3/2-way valves 21.1, 21.2, each with three connections and two switching positions, namely a first 3/2-way valve 21.1, which is arranged or interposed in particular in the heat exchanger inflow line LWT, and a second 3/2-way valve 21.2, which is arranged or interposed in particular in the heat pump inflow line L _W p. The first 3/2-way valve 21.1 is fluidically connected or connected accordingly to the primary heat source 2, the heat exchanger 4 and the second 3/2-way valve 21.2. The second 3/2-way valve 21.2 is fluidically connected to the heat exchanger 4, to the first 3/2-way valve 21.1 and to the heat pump 3 or is connected accordingly. The first 3/2-way valve 21.1 enables the heat transfer fluid 6 to flow from the primary heat source 2 to the heat exchanger 4 or to the second 3/2-way valve 21.2. The second 3/2-way valve 21.2 enables the heat transfer fluid 6 to flow from the heat exchanger 4 or from the first 3/2-way valve 21.1 to the heat pump 3. The valve 20 or the 3/2-way valves 21.1 and 21.2 are connected in terms of control technology in particular to the heat pump control and/or regulating device 14 or the corresponding switching positions of the valve 20, in particular the switching positions of the 3/2-way valves 21.1 and 21.2, can be set or switched accordingly with the aid of the heat pump control and/or regulating device 14.

These described flow paths, which can be implemented by means of the two 3/2-way valves 21.1, 21.2, could also be implemented by means of a single valve 20 (visible as a dashed illustration in Fig. 1), whereby this one valve 20 is then designed in particular as a 4/2-way valve with four connections and two switching positions, whereby in the first switching position of the valve 20 a flow of the heat transfer fluid 6 from the Primary heat source 2 via the heat exchanger 4 to the heat pump 3 is made possible, and in a second switching position of the valve 20 a flow of the heat transfer fluid 6 from the primary heat source 2 past the heat exchanger 4 to the heat pump 3 is then made possible. The switching positions of the previously described valve 20 are then also controlled or switched accordingly, in particular with the aid of the heat pump control and/or regulating device 14.

From the group of the following elements or components, namely the heat exchanger inflow line LWT, ZU at least in sections, the heat pump inflow line L _W p, zu at least in sections, the heat pump outflow line L _W p, ab at least in sections, the circulation pump 9 and the valve 20, in particular the first 3/2-way valve 21.1 and the second 3/2-way valve 21.2, at least two elements and/or components and respective associated connections are arranged and/or formed on a hydraulic module 22 forming a common structural unit. The respective previously mentioned lines can also be formed in sections in this hydraulic module.

The hydraulic module 22 is symbolized here with dash-dotted lines according to Fig. 1, whereby in particular the one valve 20 or the two 3/2-way valves 21.1, 21.2 and the circulation pump 9 are also part of the hydraulic module 22. The hydraulic module 22 can preferably be pre-assembled in a factory and/or by a heating engineer, so that the assembly effort on site, in an end customer's building, can be reduced and simple and cost-effective assembly is possible.

In the second embodiment of the central heating system 1 according to Fig.3, the heat exchanger 4 and the heat pump 3 are connected in parallel in terms of flow with respect to the primary heat source 2.

For this purpose, a heat exchanger inflow line LWT, _ZU of the line system 7 is fluidically connected on the one hand to the primary heat source 2 and on the other hand to the heat exchanger 4 or connected accordingly in order to supply the heat transfer fluid 6 to the heat exchanger 4 by means of the heating pump 8 through the heat exchanger inflow line LWT, _ZU . A heat exchanger outflow line LWT, ab of the line system 7 is further fluidically connected on the one hand to the heat exchanger 4 and on the other hand to the primary heat source 2 or connected accordingly in order to supply the heat transfer fluid 6 to the primary heat source by means of the heating pump 8 through the heat exchanger outflow line LWT, ab 2. A heat pump inflow line L _W p, _zu of the pipe system 7 is connected on the one hand to the heat exchanger inflow line L _W T, _ZU and on the other hand to the heat pump

3 are fluidically connected or connected accordingly in order to supply the heat transfer fluid 6 _to the heat pump 3 by means of the circulation pump 9 through the heat pump inflow line L _W p, . Furthermore, a heat pump outflow line L _W p, ab of the line system 7 is fluidically connected or connected accordingly on the one hand to the heat pump 3 and on the other hand to the heat exchanger outflow line L _W T, ab in order to supply the heat transfer fluid 6 to the primary heat source 2 by means of the circulation pump 9 through the heat pump outflow line LWP, ab and a part of the heat exchanger outflow line LwT.ab.

Thus, during operation of the central heating system 1, the heat transfer fluid 6 preheated by means of the heat pump 3 is first mixed with heat transfer fluid 6 coming from the heat exchanger 4 before it is (re)led to the primary heat source 2 when the heating pump 8 is also in operation in addition to the circulation pump 9. In contrast to the first embodiment, valves are not absolutely necessary in the second embodiment. The flow of heat transfer fluid 6 to the heat exchanger 4 can be generated or implemented by means of the heating pump 8 and the flow of heat transfer fluid 6 to the heat pump 3 can be generated or implemented by means of the circulation pump 9. If the heat exchanger 4 or the heat pump 3 are not to be supplied with heat transfer fluid 6 or the respective flow in the respective circuit is not to be implemented, essentially only the associated respective pump 8 or 9 needs to be switched off or then switched off. However, a reduction in the efficiency of the central heating system 1 of the second embodiment is to be expected in contrast to the first embodiment due to the described mixture of the heat transfer fluid 6 and the resulting lower temperature of the heat transfer fluid 6 supplied to the primary heat source 2. It would therefore also be conceivable to directly connect the heat pump inlet line and the heat pump outlet line to the primary heat source in order to implement the previously described parallel fluid connection of heat exchanger 4 and heat pump 3.

In the second embodiment of the central heating system 1 according to Fig.3, in particular a check valve 23 can optionally be integrated and/or arranged in the heat exchanger drain line LwT.ab or interposed here between the heat exchanger 4 and a connecting piece 24 arranged and/or formed between the heat exchanger drain line LWT, ab and the heat pump drain line L _W p, ab in order to prevent a backflow of the heat transfer fluid 6 from the heat pump 3 to the heat exchanger 4 via the heat exchanger drain line L _W T, ab. In the primary heat source 2, a distribution system (shown in dashed lines in Fig. 1 and Fig. 3) for the heat transfer fluid 6 is preferably provided, i.e. corresponding flow channels through which the heat transfer fluid 6 can flow, to which the heating circuits are each connected. The heat exchanger inflow line L _W p, _in and the heat pump outflow line LWP, off, as well as a line leading to the domestic water storage tank 5 and a line returning from the domestic water storage tank 5, which each conduct or transport the heat transfer fluid 6, are connected to the primary heat source 2, in particular to such a distribution system, or are fluidly connected to the primary heat source 2, in particular a boiler. The heat transfer fluid 6 can therefore flow through the primary heat source 2, in particular the distribution system, so that the heat transfer fluid 6 is heated during this flow, possibly also with the help of the primary heat source 2. However, the primary heat source 2, in particular the distribution system, can also be flowed through by the heat transfer fluid 6 without the heat transfer fluid 6 being heated by the primary heat source 2 during this flow, in particular without the primary heat source 2 being actively operated.

The heat pump control and/or regulating device 14 is connected in particular to the central heating control and/or regulating device 12 in order to supply energy to the heat pump control and/or regulating device 14. A connection to a power grid is also conceivable. The heat pump control and/or regulating device 14 is connected to the heating pump 8 in terms of control technology in order to control and/or regulate the heating pump 8 and/or the heat pump control and/or regulating device 14 is connected to the circulation pump 9 in terms of control technology in order to control and/or regulate the circulation pump 9 and/or the heat pump control and/or regulating device 14 is connected to the storage pump 10 in terms of control technology in order to control and/or regulate the storage pump 10 and/or the heat pump control and/or regulating device 14 is connected to an outside temperature sensor 13. a for determining an outside temperature T _a in terms of control/signal/and/or data technology. Furthermore, the heat pump control and/or regulating device 14 is effectively connected to the first temperature sensor 13.1 in terms of control/signal and/or data technology. This applies to both the first and the second embodiment of the central heating system 1 according to Fig.1 and Fig.3. These connections are symbolized using the respective dashed lines. Preferably, in the first embodiment of the central heating system 1 according to Fig.1, the valve 20, in particular the two 3/2-way valves 21.1, 21.2, are also connected in terms of control technology to the heat pump control and/or regulating device 14, which is shown in particular with the aid of a dashed line.

If the shut-off valve 23 is provided in the second embodiment of the central heating system 1 according to Fig.3, the shut-off valve 23 could also be connected in terms of control technology to the heat pump control and/or regulating device 14.

In the following, the operation and/or control and/or regulation of the central heating system 1, in particular the central heating system 1 according to Fig.1 or Fig.3, is described in more detail.

During operation and/or during control and/or during regulation of the central heating system 1, in particular the central heating system 1 according to Fig.1 or Fig.3, a heat transfer fluid 6, in particular water, is heated by means of the primary heat source 2 and/or the heat pump 3.

The heat transfer fluid 6, in particular previously heated, is optionally conveyed by means of a heating pump 8 through part of a pipe system 7 and through the heat exchanger 4 in order to heat the environment adjacent to the heat exchanger 4, in particular, for example, the interior of a building, by means of heat exchangers designed as radiators.

The heat transfer fluid 6 is optionally conveyed, in particular by means of a circulation pump 9, through another part of the pipe system 7 and through the heat pump 3 in order to heat the heat transfer fluid 6 by means of the heat pump 3.

The heat transfer fluid 6 is optionally conveyed by means of a storage pump 10 through another part of the pipe system 7, in particular for a heat transfer from the heat transfer fluid 6 to the domestic water 11 through or adjacent to the domestic water storage tank 5, to the domestic water storage tank 5 in order to heat the domestic water 11 temporarily stored in the domestic water storage tank 5, in particular, for example, so that heated domestic water is available for a shower for the residents of a building. The heat transfer fluid 6 is conveyed through and/or to the primary heat source 2 by means of the heating pump 8, in particular the circulation pump 9, and/or the storage pump 10. The primary heat source 2 is controlled and/or regulated by means of a central heating control and/or regulating device 12.

The disadvantages mentioned at the beginning are now avoided or the corresponding advantages are now realized by using a temperature sensor 13.1 to measure, determine and/or calculate an actual domestic water temperature TBI in a - viewed vertically - lower area of the domestic water storage tank 5, in particular by the heat pump control and/or regulating device 14. The heat pump 3 is controlled and/or regulated by means of a heat pump control and/or regulating device 14 depending on the determined actual domestic water temperature TBI.

This leads to several advantages, firstly, it enables simple and cost-effective control of the system. The central heating control and/or regulating device 12 and the heat pump control and/or regulating device 14 can operate essentially independently of one another or control the entire central heating system 1 essentially independently of one another. A system which initially only has one primary heat source, for example, can be easily and cost-effectively retrofitted with a heat pump 3 and the heat pump control and/or regulating device 14.

Because the first temperature sensor 13.1 determines the first actual domestic water temperature TBI in the - vertically viewed - lower area of the domestic water tank 5, the heat pump 3 can be quickly controlled without a large time delay and without a large and complex control effort using the heat pump control and/or regulating device 14. This helps to initially avoid controlling the primary heat source 2, which in turn can save fuel.

The first actual domestic water temperature TBI is therefore transmitted to the heat pump control and/or regulating device 14 and/or determined and/or calculated by means of the heat pump control and/or regulating device 14. The second, preferably average, actual domestic water temperature TB2 is measured, determined and/or calculated by means of a second temperature sensor 13.2 in a - viewed vertically - middle or upper area of the domestic water storage tank 5. The second actual domestic water temperature T _B 2 is transmitted to the central heating control and/or regulating device 12 and/or determined by means of the Central heating control and/or regulating device 12 determines and/or calculates. The primary heat source 2 is controlled and/or regulated by means of the central heating control and/or regulating device 12 depending on the second actual domestic water temperature T _B 2 .

The heat pump 3 can be operated and/or activated with the aid of the heat pump control and/or regulating device 14 to heat the heat transfer fluid 6 when the first actual domestic water temperature TBI measured, determined and/or calculated with the aid of the first temperature sensor 13.1 falls below a first limit temperature TBIG. The heat pump 3 and/or the circulation pump 9 are further controlled and/or regulated by means of the heat pump control and/or regulating device 14, in particular additionally depending on a first actual heat transfer fluid temperature Twi that forms at the outlet of the heat pump 3. In particular, a first target heat transfer fluid temperature Twi,son is set for the heat pump 3, which should be present at the outlet of the heat pump 3 when the heat pump 3 is operating. In particular, the heat pump 3 is therefore to be controlled and/or regulated as a function of the first actual heat transfer fluid temperature Twi forming at the outlet of the heat pump 3 and/or as a function of the first target heat transfer fluid temperature Twi set for the heat pump 3. If the first actual heat transfer fluid temperature Twi at the outlet of the heat pump 3 falls or rises below or above the first target heat transfer fluid temperature Twi, then the heat pump 3 is controlled and/or operated in such a way that the corresponding first actual heat transfer fluid temperature Twi then approaches the first target heat transfer fluid temperature Twi, then again, in particular the corresponding desired first actual heat transfer fluid temperature Twi, then also as the actual heat transfer fluid temperature Twi is then actually reached or realized at the outlet of the heat pump 3.

The primary heat source 2 can be operated and/or activated with the aid of the central heating control and/or regulating device 12 to heat the heat transfer fluid 6 if the second actual domestic water temperature T _B2 measured, determined and/or calculated with the aid of the second temperature sensor 13.2 falls below a second limit temperature T _B2 G. The primary heat source 2 is further controlled and/or regulated by means of the central heating control and/or regulating device 12 as a function of a second actual heat transfer fluid temperature T _W 2 that develops within or in the area of the primary heat source 2. In particular, the primary heat source 2 is additionally controlled and/or regulated as a function of a second target heat transfer fluid temperature T _W 2 set for the primary heat source 2. If the temperature of the heat transfer fluid 6 measured within the primary heat source 2, i.e. the actual heat transfer fluid temperature T W 2, falls below the second limit temperature T _B2 G. the primary heat source 2 has the set target heat transfer fluid temperature T _W 2, then the primary heat source 2 is operated accordingly in order to heat the heat transfer fluid 6 accordingly. This is also implemented accordingly with the help of the central heating control and/or regulating device 12.

These processes for operating and/or controlling and/or regulating the heat pump 3 of the central heating system 1 according to Fig.1 or Fig.3 are explained in more detail here using a schematic representation of a flow chart according to Fig.4. Firstly, it is continuously checked whether the first actual domestic water temperature TBI is below the first limit temperature TBIG. If this is the case, the method step VWPI, namely the corresponding operation/control and/or activation of the heat pump 3, is carried out. The heat pump 3 is then operated in particular until the first actual domestic water temperature TBI is again above the first limit temperature TBIG. In contrast, it is also conceivable that a first switch-off limit temperature T _B I _G ' is provided, which is preferably 4°C to 6°C above the first limit temperature T _B I _G and the heat pump 3 is then operated in particular until the first actual domestic water temperature T _B I is above the first switch-off limit temperature T _B I _G '. If the first actual domestic water temperature TBI therefore exceeds the first limit temperature TBIG or the first switch-off limit temperature T _B I _G ', the process step V _W P2 is carried out, namely a different operating mode and/or even the deactivation of the heat pump 3. The process then starts again by checking whether the first actual domestic water temperature T _B I is below the first limit temperature TBIG. The process steps described here above are carried out in particular when domestic water is taken from the domestic water storage tank, e.g. for a shower, and new "colder" domestic water is then fed back into the domestic water. The third heating circuit, in particular the storage pump 10, is activated at the same time to heat the domestic water.

The processes for operating and/or controlling and/or regulating the primary heat source 2 of the central heating system 1 according to Fig.1 or Fig.3 are explained in more detail here using a schematic representation of a flow chart according to Fig.5. Here, it is first continuously checked whether the second actual domestic water temperature T _B 2 is below the second limit temperature T _B2G . If this is the case, the process step VPRI, namely the operation and/or activation of the primary heat source 2, is carried out. The primary heat source 2 is then operated in particular until the second actual domestic water temperature T _B2 is again above the second limit temperature T _B 2G. In contrast, it is also conceivable that a second switch-off limit temperature TB2G' is provided, which is preferably 4°C to 6°C above the second limit temperature T _B 2G and the primary heat source 2 is then operated in particular until the second actual domestic water temperature T _B 2 is above the second switch-off limit temperature TB2G'. If the second actual domestic water temperature T _B 2 therefore exceeds the second limit temperature T _B 2G or the second switch-off limit temperature TB2G', the method step VPR2, namely a different operating mode and/or the deactivation of the primary heat source 2, is carried out. The method then starts again by checking whether the second actual domestic water temperature T _B 2 is below the second limit temperature TB2G. The process steps described here are carried out in particular when domestic water is taken from the domestic water storage tank, for example for a shower, and new "colder" domestic water is then fed back into the domestic water. The third heating circuit, in particular the storage pump 10, is activated at the same time to heat the domestic water or has already been activated, since the process steps described in Fig. 4 take place in particular before the process steps described in Fig. 5. Simply put, the correspondingly implemented control ensures that the heat pump 3 is preferably controlled or used before the primary heat source 2 for heating the domestic water 11.

But even in a "normal heating operation" of the central heating system, i.e. when the domestic water 11 does not have to be heated and, for example, only the heat transfer fluid 6 has to be heated to operate the heat exchanger 4, the heat pump 3 in particular can and will always be used in preference to the primary heat source 2 to heat the heat transfer fluid 6 or activated and/or controlled accordingly; this should also be pointed out again.

The first and/or the second limit temperature TBIG, T _B 2G are in particular also selected such that the primary heat source 2 is only operated and/or activated with the aid of the central heating control and/or regulating device 12 for heating the heat transfer fluid 6 when a heat requirement of the domestic hot water storage tank 5 exceeds a quantity of heat that can be provided by the heat pump 3 at maximum output of the heat pump 3. This is particularly the case when the second actual domestic hot water temperature TB2 drops below the second limit temperature T _B 2G, in particular although the heat pump 3 is operating at full capacity. When the domestic water storage tank 5 is in operation, a vertical temperature stratification of the domestic water 11 in the domestic water storage tank 5 occurs. The first actual domestic water temperature TBI is measured - viewed vertically - in a lower, first temperature layer 25.1. The second actual domestic water temperature TB2 is measured - viewed vertically - in a middle or upper, second temperature layer 25.2. The first temperature layer 25.1 forms vertically below the second temperature layer 25.2.

This temperature stratification is shown in Fig.1, Fig.2a and Fig.3 with exemplary temperatures selected between 30°C in the first, lowest temperature layer 25.1 and 45°C in the uppermost temperature layer. This temperature stratification shown in Fig.2a between 30°C in the first, lowest temperature layer 25.1 and 45°C in the uppermost temperature layer occurs in particular when the first limit temperature TBIG is lower than the second limit temperature T _B 2G and then in particular T _B I _G = 30° C and T _B2 G < 40°C, in particular T _B2 G is then selected between 35°C and 38°C.

If the second limit temperature T _B2G is lower than the first limit temperature TBIG, in particular the second limit temperature T _B2G is in particular 43°C, in particular in the range from 41°C to 45°C, and the first limit temperature TBIG is in particular 48°C and in particular in the range from 46°C to 50°C, then in particular a temperature stratification shown in Fig.2b between 50° in the first, lowest temperature layer 25.1 and 60°C in the uppermost temperature layer is established. In particular, a temperature difference between the first limit temperature TBIG and the second limit temperature T _B2G is 3°C to 7°C, preferably 5°C.

The temperatures shown in the individual layers in Fig. 2a and 2b are in particular an average temperature for the respective layer.

The first actual domestic water temperature TBI therefore has lower values than the second actual domestic water temperature T _B2 when the domestic water 11 is at rest in the domestic water tank 5 for a certain period of time. The temperature stratification can change when domestic water 11 is taken from the domestic water tank 5, in particular in its upper area, and/or "new" domestic water 11 is then fed back into the domestic water tank 5, in particular in its lower area, whereby by means of a corresponding discharge and supply concept within the domestic water tank 5 In principle, an appropriate temperature stratification can be maintained.

The fact that the primary heat source 2 is only operated and/or activated with the aid of the central heating control and/or regulating device 12 for heating the heat transfer fluid 6 when, in particular, a heat requirement of the domestic water storage tank 5 exceeds a quantity of heat that can be provided by the heat pump 3 at maximum output of the heat pump 3 is further ensured by the fact that the first actual domestic water temperature TBI is measured below the second temperature layer 25.2, wherein the domestic water 11 can be supplied in the area of the first, lowest temperature layer 25.1, in particular as shown in Fig.2a and Fig.2b. If, in comparison to the already heated domestic water 11 present in the domestic water storage tank 5, fresh, cold domestic water 11 is now supplied to the domestic water storage tank 5, the first actual domestic water temperature TBI will initially drop over time. The second actual domestic water temperature TB2 will only drop later, when the fresh, cold domestic water 11 or its temperature has spread to the second temperature sensor 13.2. When cold domestic water 11 is supplied, with an appropriate selection of the values of the limit temperatures TBIG, T _B 2G in relation to one another, the first limit temperature TBIG will therefore always be undercut by the associated first actual domestic water temperature TBI before the second limit temperature T _B 2G is undercut by the second actual domestic water temperature TB2, so that the heat pump 3 is always operated preferentially, in particular before the primary heat source 2 is operated and/or activated. If the output of the heat pump 3 is then sufficient to cover the heat requirement of the domestic water storage tank 5, the second actual domestic water temperature T _B 2 will not drop below the second limit temperature TB2G and the primary heat source 2 does not have to be activated and therefore does not have to be operated while burning fuel. The values of the limit temperatures TBIG, T _B 2G are selected in particular so that these processes take place as described above and the primary heat source 2 is activated neither too early nor too late in order to save fuel and to ensure a comfortable temperature of the domestic water 11 taken from the domestic water storage tank 5.

The first limit temperature TBIG is either below the second limit temperature T _B 2G as shown in Fig.6a or the first limit temperature TBIG is above the second limit temperature T _B 2G as shown in Fig.6b, wherein in the case that TBIG<TB2G, the temperature stratification according to Fig.2a is established in particular and wherein in the case that TBIG>TB2G or T _B 2G<TBIG, the temperature stratification according to Fig.2b is established in particular In the above-mentioned first case, the first limit temperature TBIG is set in particular to 30° C and the second limit temperature T _B 2G to < 40° C, in particular to 35° C to 38° C. In the above-mentioned second case, the first limit temperature T _B IG is set in particular in the range from 46° C to 50° C, in particular to 48° C, and the second limit temperature T _B 2G is set in the range from 41° C to 45° C, in particular to 43° C, as partially described and/or explained above.

In order to set/initiate a particularly optimal temperature control and/or temperature regulation for heating the domestic water 11 of the domestic water storage tank 5, the following steps in particular are initially carried out: In particular after installation of the system and/or before operation of the system, the domestic water storage tank 5, which is then initially completely filled with “cold” domestic water 11, is initially “only” heated by means of the primary heat source 2, or the domestic water 11 is only heated here with the aid of the heat transfer fluid 6 heated by the primary heat source 2. The heat pump 3 remains switched off in this phase. Only after the desired second actual domestic water temperature T _B2 has been reached, i.e. only when the desired second actual domestic water temperature T _B 2 is determined by the second temperature sensor 13.2, is the heat pump 3 switched on or connected. At the time when the desired temperature of the domestic water 11 or the desired second actual domestic water temperature T _B2 has been reached or determined at the second temperature sensor 13.2, the current first actual domestic water temperature T _B I present at the first temperature sensor 13.1 is then measured. In order to control the heat pump 3 for the further operation of the system, the first target heat fluid temperature Twi, son for controlling and regulating the heat pump 3, is then set to a value that is essentially 5° C higher than the above-mentioned and determined first actual domestic water temperature value TBI. The second target heat transfer fluid temperature Tw2 is then set in particular to a value 7°C to 9°C, preferably 8°C lower than Twi. Such a setting of the system prevents unnecessary operation of the primary heat source 2, wherein in particular the heat pump 3, as already described above, is then sufficient to heat the domestic water 11 present in the domestic water tank 5 accordingly, without operation of the primary heat source 2 being necessary for this. The first and/or second limit temperatures TBIG and T _B2 G are then set in particular to be 2°C to 5°C lower than the respective corresponding determined or desired first and second actual domestic water temperatures T _B I and T _B 2 or are then automatically calculated accordingly by the heat pump control and/or regulating device 14. With particular reference to Fig. 2b, the following can now be stated again: It is also conceivable that the second limit temperature T _B 2G is set lower than the first limit temperature TBIG - for example, TBIG is set to 49° C and T _B2 G is set to 43° C. In particular, this then essentially results in temperature stratification, as shown in Fig. 2b. The domestic water tank 5 here reaches an outlet temperature of 60° C in the uppermost layer, which initially provides or implements protection against bacteria and legionella. Furthermore, the stratification shown in Fig. 2b also significantly increases the usable heated water quantity of the domestic water 11 in the domestic water tank 5 (in comparison to Fig. 2a), in particular because the domestic water 11 in the domestic water tank 5 is now essentially heated up accordingly down to the lowest layer and the domestic water 11 located here is or will be heated up accordingly. However, since the usable heated water quantity is now increased in Fig. 2b, for example in comparison to Fig. 2a, the heat pump 3 can be operated with a specific blocking time even if the first actual domestic water temperature TBI falls below the first limit temperature T _B I _G. Or, to put it another way, in particular only after a specific blocking time has elapsed is the domestic water 11 in the domestic water storage tank 5 heated again with the aid of the then active heat pump 3. This reduces the required timing of the heat pump 3. In particular, a setting of T _B2 G < T _B I _G also ensures that the primary heat source 2 only contributes to heating the domestic water 11 in the domestic water storage tank 5 when the second actual domestic water temperature T _B2 falls below the second limit temperature T _B2G , which is particularly only the case when a correspondingly large quantity of already heated domestic water 11 has been or is being taken from the domestic water storage tank 5, for example by a large number of showers taking place simultaneously in an apartment building. Specific blocking times for heat pump 3 may be between 15 and 30 minutes.

The heating pump 8 is controlled and/or regulated by means of the heat pump control and/or regulating device 14, in particular as a function of an outside temperature T _a measured by means of an outside temperature sensor 13. a.

The heating pump 8 is in particular initially operated and/or activated synchronously with the heat pump 3 when the storage pump 10 is switched off, in particular deactivated. The synchronous control is made possible in particular by the fact that both the heating pump 8 and the heat pump 3 are controlled and/or regulated by means of the heat pump control and/or regulation device 14. The heating pump 8 is switched off, in particular deactivated, by means of the heat pump control and/or regulating device 14 when the storage pump 10 is operated and/or activated by means of the heat pump control and/or regulating device 14, in particular due to the withdrawal of domestic water 11 from the domestic water storage tank 5. The domestic water 11 can thus be reheated more quickly with the aid of the heat transfer fluid 6 after domestic water 11 has been withdrawn from the domestic water storage tank 5 and after and/or during the supply of fresh, cold domestic water. Alternatively, the heating pump 8 and the storage pump 10 could also be operated at the same time, although in order to heat the domestic water 11 in the domestic water storage tank 5 in the same time, a correspondingly high output would then have to be provided by means of the heat pump 3 and/or the primary heat source 2.

The heat pump 3 and/or the circulation pump 9 are controlled and/or regulated by means of the heat pump control and/or regulating device 14, in particular additionally as a function of a first actual heat transfer fluid temperature Twi that forms at the outlet of the heat pump 3 and/or as a function of a first target heat transfer fluid temperature Twi,son that is predetermined at the outlet of the heat pump 3 or in the area of the outlet of the heat pump 3. The previously mentioned method step VWPI (see also Fig. 4), namely the operation and/or control of the heat pump 3, is thus also carried out as a function of this first actual heat transfer fluid temperature Twi and this first target heat transfer fluid temperature Twi,son, in particular in order to then heat the domestic water 11 accordingly. Different types of controls and/or regulation for the heat pump 3 and/or the circulation pump 9 can be used, which are implemented, for example, with the help of digital programs or with the help of analog circuits.

The primary heat source 2 is controlled and/or regulated by means of the central heating control and/or regulating device 12 as a function of a second actual heat transfer fluid temperature T _W 2 - which forms within or in the area of the primary heat source 2 - and/or as a function of a second target heat transfer fluid temperature Tw2,son specified for the area of the primary heat source 2. The previously mentioned method step V _PRi (cf. Fig. 5), namely the operation and/or control, in particular the activation of the primary heat source 2, is thus carried out as a function of this second actual heat transfer fluid temperature TW2 and this second target heat transfer fluid temperature T _W 2,son. Different types of controls and/or regulation can also be used for the heating pump 8 and/or the storage pump 10, which are or will be implemented, for example, with the aid of digital programs or with the aid of analog circuits.

The second target heat transfer fluid temperature T _W 2,son is in particular below the first target heat transfer fluid temperature Twi,son such that the primary heat source 2 is only operated and/or activated with the aid of the central heating control and/or regulating device 12 for heating the heat transfer fluid 6 when a heat requirement of the central heating system 1, in particular a heat requirement of the heat exchanger 4 and/or the domestic hot water storage tank 5, exceeds a quantity of heat that can be provided by means of the heat pump 3 at maximum output of the heat pump 3.

The heat transfer fluid 6 heated by the heat pump 3 is fed to the primary heat source 2 directly according to Fig.1 and, according to Fig.3, possibly mixed with heat transfer fluid 6 coming from the heat exchanger 4. While flowing through the heat pump discharge line Lwp.ab, a small heat loss will occur, which leads to a drop in the temperature of the heat transfer fluid 6. Any mixing of the heat transfer fluid 6 coming from the heat pump 3 with the heat transfer fluid 6 coming from the heat exchanger 4 will also lead to a drop in the temperature of the heat transfer fluid 6 coming from the heat pump 3.

However, if the output of the heat pump 3 is sufficient to cover the heat requirement of the central heating system 1, in particular the heat requirement of the heat exchanger 4 and/or the domestic hot water storage tank 5, then the heat transfer fluid 6 will reach the primary heat source 2 with an actual heat transfer fluid temperature above the second target heat transfer fluid temperature TW2, son, so that the second actual heat transfer fluid temperature T _W 2 then present in the primary heat source 2 is also above the second target heat transfer fluid temperature T _W 2, SOII and the primary heat source 2 therefore does not have to be activated and operated with the combustion of fuels.

The values of the target heat transfer fluid temperatures Twi, son, T _W 2, son are also selected in particular so that the processes take place as described above and the primary heat source 2 is activated neither too early nor too late in order to save fuel and to ensure a comfortable room temperature generated by means of the heat exchangers 4 and/or the domestic water 11 taken from the domestic water storage tank 5. The first target heat transfer fluid temperature Twi,son and/or the first limit temperature TBIG is determined by means of a table and/or formula stored in the heat pump control and/or regulating device 14 and/or, in particular, the first target heat transfer fluid temperature Twi.soii is determined as a function of an outside temperature T _a measured and/or determined by means of the outside temperature sensor 13.a and/or is calculated as a function of a desired room temperature. In particular, the first target heat transfer fluid temperature Twi.soii is 55°C to 65°C, in particular 59°C to 61°C.

In particular, at lower outside temperatures T _{a ,} higher first target heat transfer fluid temperatures Twi,son are selected, in particular in order to compensate for the higher heat losses to the environment that occur at lower outside temperatures T _a .

The second target heat transfer fluid temperature T _W 2, son and/or the second limit temperature T _B 2G is determined by means of a table and/or formula stored in the central heating control and/or regulating device 12, and/or in particular the second target heat transfer fluid temperature TW2, son is determined as a function of an outside temperature T _a measured and/or determined by means of a preferably further outside temperature sensor 13.b and/or is calculated as a function of a desired room temperature. In particular, the second target heat transfer fluid temperature T _W 2, son is 51 °C to 53 °C at an outside temperature between -1 °C and +1 °C.

In particular, at lower outside temperatures T _{a ,} higher second target heat transfer fluid temperatures TW2, son are selected, in particular to compensate for the higher heat losses to the environment that occur at lower outside temperatures T _a .

Fig.6a and Fig.6b show in a very simplified schematic representation a respective dependency of the first target heat transfer fluid temperature Twi. soii, the first limit temperature T _B IG, the second target heat transfer fluid temperature T _W 2, son or the second limit temperature T _B2 G on the outside temperature T _a , as these are stored, for example, in tabular form or as a formula in the heat pump control and/or regulating device 14 or in the central heating control and/or regulating device 12. Here in Fig.6a and Fig.6b, the respective graphs for the aforementioned temperature values are shown as examples and in a highly simplified schematic. The first and second limit temperatures T _B IG, T _B2 G are shown as horizontal lines parallel to the X-axis of the outside temperature T _a according to Fig.6a and Fig.6b. The first and second limit temperatures T _B IG, T _B2 G are thus in particular constant values. in the heat pump control and/or regulating device 14 or in the central heating control and/or regulating device 12, so that the first and second limit temperatures TBIG, T _B 2G are, for the sake of simplicity, independent of the outside temperature T _a .

A temperature difference between the first target heat transfer fluid temperature Twi,son and the second target heat transfer fluid temperature T _W 2,son is preferably 7°C to 9°C, in particular 8°C with T _W 2,son < Twi,son. The second limit temperature T _B 2G is smaller than the second target heat transfer fluid temperature T _W 2,son. In this way, in particular, effective heating of the domestic water 11 can be achieved by means of the primary heat source 2.

Finally, it should also be pointed out that the central heating control and/or regulating device 12 and/or the heat pump control and/or regulating device 14 can be designed as a computer and/or have corresponding microprocessors for implementing the desired calculations and/or control sequences. As already mentioned above, the central heating system 1 then has in particular a separate central heating control and/or regulating device 12 and a separate heat pump control and/or regulating device 14. In particular, when the central heating system 1 is retrofitted, the central heating control and/or regulating device 12 does not have to be adapted at all or - if - only to a very small extent. In particular, the central heating control and/or regulating device 12 and the heat pump control and/or regulating device 14 in the central heating system 1 therefore work essentially independently of one another, thereby avoiding more complex control effort and the associated costs.

List of reference symbols

1 central heating system

2 Primary heat source

3 Heat pump

4 heat exchangers

5 domestic hot water tanks

6 Heat transfer fluid

7 Pipeline system

8 Heating pump

9 Circulation pump

10 Storage pump

11 Domestic water

12 Central heating control and/or regulation device

13.1 first temperature sensor

13.2 second temperature sensor

13. a Outside temperature sensor

13. b Outside temperature sensor

14 Heat pump control and/or regulation device

15 Inflow valve

15. r Check valve

16 Inflow connection

17 Domestic water supply line,

18 T-piece

19 inverters

20 Valve

21.1 first 3/2-way valve

21.2 second 3/2-way valve

22 Hydraulic module

23 Shut-off valve

24 Connector

25.1 first temperature layer

25.2 second temperature layer

TBI first actual domestic water temperature

TB2 second actual domestic water temperature TBIG first limit temperature

TBIG‘ first switch-off limit temperature

T _B 2G second limit temperature

TB2G‘ second switch-off limit temperature

T _a outside temperature

Twi first actual heat transfer fluid temperature

TW2 second actual heat transfer fluid temperature

Twi . soii first target heat transfer fluid temperature

TW2, second target heat transfer fluid temperature

LWT, ZU heat exchanger inflow line

LWT, from heat exchanger drain line

LWP, to heat pump inlet line

LWP, from heat pump drain line

VWPI Operating and/or activating the heat pump 3

V _W P2 Deactivation of heat pump 3

VPRI Operating and/or activating the primary heat source 2

VPR2 Deactivating primary heat source 2

Claims

Patent claims

1. Central heating system (1) with at least one primary heat source (2) that can be operated with the aid of fuels, in particular a heating boiler and/or a gas boiler, with at least one electrically operated heat pump (3), with at least one heat exchanger (4), preferably a heating element or a radiator for heating a building, and with at least one domestic water storage tank (5), wherein a heat transfer fluid (6), in particular water, can be heated by means of the primary heat source (2) and/or with the aid of the heat pump (3), wherein the heat transfer fluid (6), in particular previously heated, can be conveyed through the heat exchanger (4) by means of a pipe system (7) and by means of a heating pump (8), wherein the heat transfer fluid (6) can be conveyed by means of the pipe system (7), in particular with the aid of a circulation pump (9), for heating it by the heat pump (3), wherein the heat transfer fluid (6) can be conveyed by means of the pipe system (7) and a storage pump (10) for heating water stored in the domestic water storage tank (5) temporarily stored domestic water (11), in particular for heat transfer from the heat transfer fluid (6) to the domestic water (11) through or adjacent to the domestic water storage tank (5), can be conveyed to the domestic water storage tank (5), wherein the heat transfer fluid (6) can be conveyed through or to the primary heat source (2) by means of the heating pump (8), in particular the circulation pump (9), and/or the storage pump (10), wherein a central heating control and/or regulating device (12) is connected to the primary heat source (2) for control and/or regulation thereof, characterized in that a temperature sensor (13.1) is arranged in a - viewed vertically - lower region of the domestic water storage tank (5) or adjacent to this - viewed vertically - lower region of the domestic water storage tank (5) for determining the actual domestic water temperature (TBI), wherein the temperature sensor (13.1) is connected to a heat pump control and/or regulating device (14) for control/signal/ and/or is connected for data purposes, wherein the heat pump (3) is connected for control purposes to the heat pump control and/or regulating device (14), and wherein the heat pump control and/or regulating device (14) is designed and/or constructed such that the heat pump (3) can be controlled and/or regulated as a function of the determined actual domestic water temperature (TBI).

2. Central heating system (1) according to claim 1, characterized in that the temperature sensor (13.1) is arranged in or on a part of a service water inflow line (17) formed between an inflow valve (15) and an inflow connection (16) of the service water storage tank (5), in particular by means of a T-piece (18).

3. Central heating system (1) according to claim 1 or 2, characterized in that the temperature sensor (13.1) is designed as a first temperature sensor (13.1) for determining a first actual domestic water temperature (TBI), wherein a second temperature sensor (13.2) is arranged in a - viewed vertically - middle or upper region of the domestic water tank (5) for measuring a second, preferably average actual domestic water temperature (TB2), wherein the second temperature sensor (13.2) is connected to the central heating control and/or regulating device (12) in terms of control/signal/and/or data technology, wherein the central heating control and/or regulating device (12) is designed and/or constructed such that the primary heat source (2) can be controlled and/or regulated as a function of the second actual domestic water temperature (TB2).

4. Central heating system (1) according to claim 3, characterized in that the heat pump control and/or regulating device (14) is designed and/or constructed such that the heat pump (3) can be operated and/or activated with the aid of the heat pump control and/or regulating device (14) to heat the heat transfer fluid (6) when the first actual domestic water temperature (TBI) measured, determined and/or calculated with the aid of the first temperature sensor (13.1) falls below a first limit temperature (TBIG), wherein the central heating control and/or regulating device (12) is designed and/or constructed such that the primary heat source (2) can be operated and/or activated with the aid of the central heating control and/or regulating device (12) to heat the heat transfer fluid (6) when the first actual domestic water temperature (TBI) measured, determined and/or calculated with the aid of the first temperature sensor (13.2) falls below a first limit temperature (TBIG), wherein the central heating control and/or regulating device (12) is designed and/or constructed such that the primary heat source (2) can be operated and/or activated with the aid of the central heating control and/or regulating device (12) to heat the heat transfer fluid (6) when the first actual domestic water temperature (TBI) measured, determined and/or calculated with the aid of the second temperature sensor (13.2) falls below a first limit temperature (TBIG). calculated second actual domestic water temperature (TB2) falls below a second limit temperature (T _B 2G).

5. Central heating system (1) according to one of the preceding claims, characterized in that a power of the heat pump (3) is continuously adjustable, in particular between 0 kW and 25 kW, in particular between 1.5 kW and 7 kW, by means of the heat pump control and/or regulating device (14), in particular an inverter (19) of the heat pump control and/or regulating device (14).

6. Central heating system (1) according to one of the preceding claims, characterized in that the central heating control and/or regulating device (12) and the heat pump control and/or regulating device (14) are designed separately from one another so that they do not directly influence each other and the controls and/or regulations carried out by means of the central heating control and/or regulating device (12) and those carried out by means of the heat pump control and/or regulating device (14) are independent of each other.

7. Central heating system (1) according to one of the preceding claims, characterized in that the heat exchanger (4) and the heat pump (3) are fluidically connected in series with respect to the primary heat source (2) or can be connected in series.

8. Central heating system (1) according to one of the preceding claims, in particular according to claim 7, characterized in that a heat exchanger inflow line (L _W T, _ZU ) of the line system (7) is fluidically connected on the one hand to the primary heat source (2) and on the other hand to the heat exchanger (4) in order to supply the heat transfer fluid (6) to the heat exchanger (4) by means of the heating pump (8) through the heat exchanger inflow line (LWT, ZU), wherein a heat pump inflow line (L _W p, zu) of the line system (7) is fluidically connected on the one hand to the heat exchanger (4) and on the other hand to the heat pump (3) in order to supply the heat transfer fluid (6) to the heat pump (3) through the heat pump inflow line (LWP, zu), wherein a heat pump outflow line (LWP, ab) of the line system (7) is fluidically connected on the one hand to the heat pump (3) and on the other hand to the primary heat source (2) in order to supply the Heat transfer fluid (6) is to be supplied to the primary heat source (2) through the heat pump discharge line (LWP, ab).

9. Central heating system (1) according to claim 8, characterized in that the line system (7) has at least one valve (20), by means of which the heat transfer fluid (6) can be directed and/or guided optionally from the primary heat source (2) to the heat exchanger (4) or past the heat exchanger (4) to the heat pump (3).

10. Central heating system (1) according to claim 8 or 9, characterized in that the line system (7) has two 3/2-way valves (21.1, 21.2), each with three connections and two switching positions, namely a first 3/2-way valve (21.1), which is arranged in particular in the heat exchanger inflow line (LWT, ZU) and/or is interposed therein, and a second 3/2-way valve (21.2), which is arranged in particular in the heat pump inflow line (LWP, ZU) and/or is interposed therein, wherein the first 3/2-way valve (21.1) is fluidically connected to the primary heat source (2), the heat exchanger (4) and to the second 3/2-way valve (21.2), wherein the second 3/2-way valve (21.2) is fluidically connected to the heat exchanger (4), to the first 3/2-way valve (21.1) and to the heat pump (3), wherein the first 3/2-way valve (21.1) selectively enables a flow of the heat transfer fluid (6) from the primary heat source (2) to the heat exchanger (4) or to the second 3/2-way valve (21.2), and wherein the second 3/2-way valve (21.2) selectively enables a flow of the heat transfer fluid (6) from the heat exchanger (4) or from the first 3/2-way valve (21.1) to the heat pump (3).

11. Central heating system (1) according to one of claims 8 to 10, characterized in that from the group of the following elements and/or components, namely the heat exchanger inflow line (LWT, ZU) at least in sections, the heat pump inflow line (L _W p, zu) at least in sections, the heat pump outflow line (Lwp,at>) at least in sections, the circulation pump (9) and the valve (20), in particular the first 3/2-way valve (21.1) and the second 3/2-way valve (21.2), at least two elements and/or components and respectively associated connections are arranged and/or formed on a hydraulic module (22) forming a common structural unit.

12. Central heating system (1) according to one of claims 1 to 6, characterized in that the heat exchanger (4) and the heat pump (3) are connected in parallel in terms of flow with respect to the primary heat source (2).

13. Central heating system (1) according to one of the preceding claims, in particular according to one of claims 1 to 6 and/or according to claim 12, characterized in that a heat exchanger inflow line (LWT, ZU) of the line system (7) is fluidically connected on the one hand to the primary heat source (2) and on the other hand to the heat exchanger (4) in order to supply the heat transfer fluid (6) to the heat exchanger (4) by means of the heating pump (8) through the heat exchanger inflow line (LWT, ZU), wherein a heat exchanger outflow line (LWT, ab) of the line system (7) is fluidically connected on the one hand to the heat exchanger (4) and on the other hand to the primary heat source (2) in order to return the heat transfer fluid (6) to the primary heat source (2) by means of the heating pump (8) through the heat exchanger outflow line (LWT, ab), wherein a heat pump inflow line (L _W p, zu) of the line system (7) is fluidically connected on the one hand to the Heat exchanger inflow line (LWT, ZU) and on the other hand is fluidically connected to the heat pump (3) in order to supply the heat transfer fluid (6) by means of the circulation pump (9) through the heat pump inflow line (L _W p, zu) to the heat pump (3), wherein a Heat pump drain line (Lwp,at>) of the line system (7) is fluidically connected on the one hand to the heat pump (3) and on the other hand to the heat exchanger drain line (LWT,ab) in order to supply the heat transfer fluid (6), in particular by means of the circulation pump (9), through the heat pump drain line (L _W p,ab) and part of the heat exchanger drain line (LWT,ab) to the primary heat source (2).

14. Central heating system (1) according to claim 13, characterized in that a check valve (23) is interposed between the heat exchanger (4) and a connecting piece (24) arranged and/or formed between the heat exchanger drain line (LWT, ab) and the heat pump drain line (L _W p, ab) in the heat exchanger drain line (LWT, ab) in order to prevent a backflow of the heat transfer fluid (6) from the heat pump (3) to the heat exchanger (4) via the heat exchanger drain line (LWT, ab).

15. Central heating system (1) according to one of the preceding claims, characterized in that the heat pump control and/or regulating device (14) for supplying energy to the heat pump control and/or regulating device (14) is connected to the central heating control and/or regulating device (12) and/or that the heat pump control and/or regulating device (14) for controlling and/or regulating the heating pump (8) is connected to the heating pump (8) in terms of control technology and/or that the heat pump control and/or regulating device (14) for controlling and/or regulating the circulation pump (9) is connected to the circulation pump (9) in terms of control technology and/or that the heat pump control and/or regulating device (14) for controlling and/or regulating the storage pump (10) is connected to the storage pump (10) in terms of control technology and/or that the heat pump control and/or regulating device (14) for controlling and/or regulating the valve (20), in particular the first and second 3/2-way valves (21.1 and 21.2 respectively), and/or that the heat pump control and/or regulating device (14) is connected in terms of control/signal/and/or data technology to an outside temperature sensor (13.a) for determining an outside temperature (T _a ).

16. Method for operating and/or controlling and/or regulating a central heating system (1), in particular a central heating system (1) according to one of claims 1 to 15, wherein the central heating system (1) comprises at least one primary heat source (2) operable with the aid of fuels, in particular a boiler or a gas boiler, at least one electrically operable heat pump (3), at least one heat exchanger (4), preferably a heating element or a radiator for heating a Building, and at least one domestic water storage tank (5), wherein a heat transfer fluid (6), in particular water, is heated by means of the primary heat source (2) and/or the heat pump (3), wherein the heat transfer fluid (6), in particular previously heated, can be and/or is selectively conveyed by means of a heating pump (8) through a part of a pipe system (7) and through the heat exchanger (4) in order to heat the environment adjacent to the heat exchanger (4) by means of the heat exchanger (4), wherein the heat transfer fluid (6) is selectively conveyed, in particular by means of a circulation pump (9), through a further part of the pipe system (7) and through the heat pump (3) in order to heat the heat transfer fluid (6) by means of the heat pump (3), wherein the heat transfer fluid (6) is selectively conveyed by means of a storage pump (10) through a further part of the pipe system (7), in particular for heat transfer from the heat transfer fluid (6) to the domestic water (11) by or adjacent to the domestic water storage tank (5), is conveyed to the domestic water storage tank (5) in order to heat the domestic water (11) temporarily stored in the domestic water storage tank (5), wherein the heat transfer fluid (6) is conveyed through or to the primary heat source (2) by means of the heating pump (8), in particular the circulation pump (9), and/or the storage pump (10), and wherein the primary heat source (2) is controlled and/or regulated by means of a central heating control and/or regulating device (12), characterized in that with the aid of a temperature sensor (13.1) an actual domestic water temperature (TBI) in a - viewed vertically - lower region of the domestic water storage tank (5) is measured, determined and/or calculated, in particular by a heat pump control and/or regulating device (14), and wherein the heat pump (3) is controlled and/or regulated by means of a heat pump control and/or regulating device (14) depending on the determined actual domestic water temperature (TBI).

17. Method according to claim 16, characterized in that the temperature sensor (13.1) is designed as a first temperature sensor (13.1) for measuring and/or determining a first actual domestic water temperature (TBI), wherein the first actual domestic water temperature (TBI) is transmitted to the heat pump control and/or regulating device (14) and/or is determined and/or calculated by means of the heat pump control and/or regulating device (14), wherein a second, preferably average, actual domestic water temperature (TB2) is measured, determined and/or calculated by means of a second temperature sensor (13.2) in a - viewed vertically - middle or upper region of the domestic water storage tank (5), wherein the second actual domestic water temperature (T _B 2) is transmitted to the central heating control and/or regulating device (12) and/or is determined and/or calculated by means of the central heating control and/or regulating device (12), and wherein the primary heat source (2) is controlled and/or regulated by means of the central heating control and/or regulating device (12) as a function of the second actual domestic water temperature (T _B 2).

18. Method according to claim 17, characterized in that the heat pump (3) is operated and/or activated with the aid of the heat pump control and/or regulating device (14) for heating the heat transfer fluid (6) when the first actual domestic water temperature (TBI) measured, determined and/or calculated with the aid of the first temperature sensor (13.1) falls below a first limit temperature (TBIG), and wherein the primary heat source (2) is operated and/or activated with the aid of the central heating control and/or regulating device (12) for heating the heat transfer fluid (6) when the second actual domestic water temperature (TB2) measured, determined and/or calculated with the aid of the second temperature sensor (13.2) falls below a second limit temperature (TBIG).

19. Method according to claim 18, characterized in that the first and the second limit temperature (TBIG, T _B 2G) are selected such that the primary heat source (2) is only operated and/or activated with the aid of the central heating control and/or regulating device (12) for heating the heat transfer fluid (6) when a heat requirement of the domestic water storage tank (5) exceeds a quantity of heat that can be provided by means of the heat pump (3) at maximum output of the heat pump (3).

20. Method according to one of claims 17 to 19, characterized in that during operation of the domestic water storage tank (5) a vertical temperature stratification of the domestic water (11) in the domestic water storage tank (5) is established, wherein the first actual domestic water temperature (TBI) is measured in a lower, first temperature layer (25.1), wherein the second actual domestic water temperature (TB2) is measured in a middle or upper, second temperature layer (25.2), wherein the first temperature layer (25.1) is formed vertically below the second temperature layer (25.2).

21. Method according to one of claims 16 to 20, characterized in that the heating pump (8), in particular as a function of an outside temperature (T _a ) measured by means of an outside temperature sensor (13.a), is controlled and/or regulated by means of the heat pump control and/or regulating device (14).

22. Method according to one of claims 16 to 21, characterized in that the heating pump (8) is switched off by means of the heat pump control and/or regulating device (14) when the storage pump (10), in particular due to a withdrawal of Domestic water (11) from the domestic water storage tank (5) is operated and/or activated by means of the heat pump control and/or regulating device (14).

23. Method according to one of claims 16 to 22, characterized in that the heat pump (3) and/or the circulation pump (9) are controlled and/or regulated by means of the heat pump control and/or regulating device (14), in particular additionally, as a function of a first actual heat transfer fluid temperature (Twi) forming at the outlet of the heat pump (3) and/or as a function of a first target heat transfer fluid temperature (Twi.soii) predetermined for the outlet of the heat pump (3).

24. Method according to one of claims 16 to 23, characterized in that the

Primary heat source (2) by means of the central heating control and/or regulating device (12) depending on a second actual heat transfer fluid temperature (T _W 2) - which develops within or in the area of the primary heat source (2) - and/or depending on a second target temperature - which is predetermined for the inner area of the primary heat source (2).

Heat transfer fluid temperature (TW2, SOII) is controlled and/or regulated.

25. Method according to claim 24, characterized in that the second target heat transfer fluid temperature (TW2, son) is below the first target heat transfer fluid temperature (Twi, son) in such a way that the primary heat source (2) is only operated and/or activated with the aid of the central heating control and/or regulating device (12) for heating the heat transfer fluid (6) when a heat requirement of the central heating system (1), in particular a heat requirement of the heat exchanger (4) and/or the domestic water storage tank (5), exceeds a quantity of heat that can be provided by means of the heat pump (3) at maximum output of the heat pump (3).

26. Method according to one of claims 23 to 25, characterized in that the first target heat transfer fluid temperature (Twi, son) and/or the first limit temperature (TBIG) are determined by means of a table and/or formula stored in the heat pump control and/or regulating device (14), in particular the first target heat transfer fluid temperature (Twi.soii) is determined as a function of an outside temperature (T _a ) measured and/or determined by means of the outside temperature sensor (13. a) and/or is calculated as a function of a desired room temperature, in particular wherein the first target heat transfer fluid temperature (Twi.soii) is 55°C to 65°C, in particular 59°C to 61°C.

27. Method according to one of claims 24 to 26, characterized in that the second target heat transfer fluid temperature (T _W 2, son) and/or the second limit temperature (T _B 2G) are determined by means of a table and/or formula stored in the central heating control and/or regulating device (12), in particular the second target heat transfer fluid temperature (TW2, SOII) is determined as a function of an outside temperature (T _a ) measured and/or determined by means of a preferably further outside temperature sensor (13.b) and/or is calculated as a function of a desired room temperature, in particular wherein the second target heat transfer fluid temperature (T _W 2, son) is 51°C to 53°C at an outside temperature (T _a ) between -1 °C and +1°C.

28. Method according to one of claims 16 to 27, characterized in that the control of the primary heat source (2) takes place exclusively with the aid of the central heating control and/or regulating device (12) and the control of the heat pump (3) takes place exclusively with the aid of the heat pump control and/or regulating device (14).