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

Abstract

The invention relates to a central heating system (1) comprising at least one primary heat source (2) which can be operated using fuels, at least one electrically operatable heat pump (3), at least one water-air heat exchanger (4), and at least one service water storage device (5) for temporarily storing service water (11). A heat exchanger supply line (LWT, zu) of the line system (7) is fluidically connected to the primary heat source (2) and to the water-air heat exchanger (4), and a heat pump discharge line (LWP, ab) of the line system (7) is fluidically connected to the heat pump (3) and to the primary heat source (2). The invention also relates to a method for operating and / or controlling and / or regulating such a central heating system (1). In particular, the fuel requirement for the primary energy source (2) is minimized in a distributed manner over the year in that – a first 3 / 2-way valve (21.1) is arranged in the heat exchanger supply line (LWT, zu), and – a first 3-way connecting piece (26.1) is arranged in the heat pump discharge line (LWP, ab) such that a branching flow circuit (KAB) of the line system (7) is formed by means of a branch of the 3 / 2-way valve (21.1) and a branch of the 3-way connecting piece (26.1), wherein the heat transfer fluid (6) can be pumped through the branching flow circuit (KAB) by means of the at least one pump (8, 9, 9b), and the service water (11) can be heated using the heat transfer fluid (6) flowing through the branching flow circuit (KAB).

Description

[0001] Central heating system and method for operating and / or controlling and / or regulating a central heating system

[0002] The invention relates to a central heating system having the features of the preamble of patent claim 1 or 2 and to a method for operating and / or controlling and / or regulating a central heating system having the features of the preamble of patent claim 21 or 22.

[0003] The central heating systems known in the prior art generally have at least one primary heat source operable with the aid of fuels, in particular a gas boiler or a heating boiler. Some central heating systems also have an electrically operated heat pump, but at least one water-air heat exchanger, preferably a heater or a radiator for heating a building, and / or at least one domestic hot water storage tank, in particular a boiler, for temporarily storing domestic hot water. A heat transfer fluid, in particular water, can be heated with the aid of the primary heat source and / or with the aid of the heat pump, wherein the heat transfer fluid can be conveyed by means of a piping system and with the aid of at least one pump, in particular a heat pump, a circulation pump, and / or a heat source pump, for heating the heat transfer fluid by the heat pump and / or, in particular, for heating the heat transfer fluid by the primary heat source.A heat exchanger inflow line of the piping system is fluidly connected and / or connected accordingly to the primary heat source on the one hand and to the water-air heat exchanger on the other hand, so that the heat transfer fluid can be fed to the water-air heat exchanger through the heat exchanger inflow line. A heat pump inflow line of the piping system is fluidly connected and / or connected accordingly to the water-air heat exchanger on the one hand and to the heat pump on the other hand, so that the heat transfer fluid can be fed to the heat pump through the heat pump inflow line. A heat pump outflow line of the piping system is fluidly connected and / or connected accordingly to the heat pump on the one hand and to the primary heat source on the other, so that the heat transfer fluid can be fed to the primary heat source through the heat pump outflow line.The water-to-air heat exchanger and the heat pump are thus connected in series and / or connectable in series in terms of flow technology with respect to the primary heat source. DE 29 19 751 C2 describes a central heating system with a heat transfer fluid that can be heated or warmed with fuel in a boiler. 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 inlet line, also called a flow line, through which the heat transfer fluid is fed to the water-to-air heat exchangers designed as radiators. The heating circuit also has a heat exchanger outlet line, also called a return line, through which the heat transfer fluid is then fed from the radiators back to the boiler.With the help of a four-way mixing valve installed in the flow and return lines and a heating pump assigned to the radiators, the proportion of heat transfer fluid flowing to the radiators can be adjusted. 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 returned at an elevated temperature from the heat pump to 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 a further temperature sensor measures the temperature of the supply air, which is fed to an evaporator of the heat pump. The heat pump and boiler can be operated separately or simultaneously. The heat pump is switched on when the outside temperature falls below 3°C or below 10°C.5°C for economic reasons. In a range around these 3°C or 5°C, the actual heat transfer fluid temperature at the boiler is maintained at 55°C by the boiler, so the heat pump is not activated as frequently.

[0004] However, such a central heating system is not yet optimally designed with regard to fuel savings potential, particularly because the heat pump is only operated above an outside temperature of 3°C or 5°C. At outside temperatures of 3°C or 5°C (or below), the boiler is preferably operated and the heat pump is only switched on when needed and rarely, so that heat is preferably provided by the fuels within the aforementioned temperature range. Furthermore, the control and / or regulation of the aforementioned four-way mixing valve is complex, particularly if the heat pump is retrofitted to an existing heating system. Control and / or regulation of the aforementioned four-way mixing valve using the heat pump is then not possible or only possible with major control and regulation modifications to the central heating system.Such four-way mixing valves or similar valves are often additionally installed in a boiler housing and are therefore inaccessible when retrofitting the heat pump. The invention is therefore based on the object of designing and / or 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 throughout the year, in particular the design and / or control complexity is reduced, and in particular the associated costs are also reduced.

[0005] This problem underlying the invention is now initially solved - for the central heating system - with the features of patent claim 1.

[0006] One aspect of the invention essentially lies in the fact that a first 3 / 2-way valve is arranged in the heat exchanger inlet line and / or is interposed therein. A first 3-way connector is arranged in the heat pump outlet line and / or is interposed therein, so that a branch flow circuit of the piping system is formed by means of a branch of the 3 / 2-way valve and a branch of the 3-way connector. The heat transfer fluid can be pumped through the branch flow circuit by means of the at least one pump, and the domestic water can be heated with the aid of the heat transfer fluid flowing through the branch flow circuit.

[0007] The problem underlying the invention is also solved - also for the central heating system - with the features of the independent and co-ordinate patent claim 2.

[0008] One aspect of the invention then essentially lies in the fact that a - first - 3-way connecting piece is arranged in the heat exchanger inflow line and / or is interposed here, wherein a - first - 3 / 2-way valve is arranged in the heat pump outflow line and / or is interposed here, so that by means of a branch of the 3-way connecting piece and a branch of the 3 / 2-way valve a branch flow circuit of the line system is formed, wherein the heat transfer fluid can be conveyed through the branch flow circuit by means of the at least one pump and the domestic water can be heated with the aid of the heat transfer fluid flowing through the branch flow circuit.

[0009] These two approaches create a structurally simple solution for heating domestic water, whereby this heating of the domestic water is then also easy to implement in terms of control / regulation, with only the activation of the respective 3 / 2-way valve having to be carried out accordingly. This design of the branch flow circuit is particularly useful if the heat pump is or will be retrofitted to an existing system. Such a branch flow circuit can be connected or integrated into an existing system without any major effort. The lines described here can be designed easily and cost-effectively using pipes and / or hoses and / or flow channels formed in housings.

[0010] It should be noted at this point that a 3 / 2-way valve can be designed, in particular, using a 3-way connector and a valve body, whereby two different flow paths can be realized through the 3-way connector by means of the valve body. In this respect, it is also conceivable to replace the respective - first - 3-way connector with another 3 / 2-way valve, which is then controlled accordingly to realize the respective flow paths.

[0011] With regard to the term “domestic water storage tank,” it should be briefly pointed out 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 can be drawn from the domestic water storage tank, for example, for showering at home, or for cooking or dishwashing at home, with new fresh water then being added to the domestic water storage tank to refill it. The designation “domestic water storage tank” therefore does not mean that previously used and / or contaminated water is stored in this tank, but rather that the water stored and / or saved therein 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.

[0012] Preferably, a heating line is arranged and / or formed within the domestic hot water storage tank, within a wall of the domestic hot water storage tank, and / or externally on the wall of the domestic hot water storage tank, so that when the heat transfer fluid flows through the heating line, the domestic hot water then present in the domestic hot water storage tank can be heated by the heat transfer fluid. A primary heat source drain line of the piping system is fluidly connected and / or connected accordingly to the primary heat source on the one hand and to the heating line on the other, so that the heat transfer fluid can be supplied to the heating line through the primary heat source drain line.A primary heat source inflow line of the piping system is fluidly connected to the heating line on the one hand and to the primary heat source on the other hand, and / or connected accordingly, so that the heat transfer fluid can be supplied to the primary heat source through the primary heat source inflow line. The heat exchanger inflow line is fluidly connected to the primary heat source outflow line and / or connected to the primary heat source outflow line. The heat pump outflow line is fluidly connected to the primary heat source inflow line and / or connected to the primary heat source inflow line, in particular by means of a primary heat source 3 / 2-way valve.

[0013] In this way, the overall effort required to set up the piping system is minimized, as the necessary pipe connections between each other or with valves are kept as small as possible.

[0014] In a preferred embodiment of the central heating system, a branch flow circuit inflow line of the branch flow circuit is fluidly connected to the primary heat source outflow line and / or connected to the primary heat source outflow line via the first 3-way connector or via the first 3 / 2-way valve and via a second 3-way connector arranged in the primary heat source outflow line and / or interposed therein. A branch flow circuit outflow line of the branch flow circuit is fluidly connected to the primary heat source inflow line and / or connected to the primary heat source inflow line via the first 3 / 2-way valve or via the first 3-way connector and via a third 3-way connector.

[0015] This further simplifies the subsequent integration of a heat pump into an existing central heating system. To create the aforementioned connections between the branch flow circuit drain line and the branch flow circuit inflow line with the primary heat source drain line and the primary heat source inflow line, only the second and third 3-way connectors need to be inserted into the primary heat source drain line and the primary heat source inflow line and fluidically connected to the branch flow circuit drain line and the branch flow circuit inflow line, respectively. This can be achieved with minimal manual effort. Further preferably, the primary heat source has a primary heat source housing, and the domestic hot water storage tank has a domestic hot water storage tank housing arranged at a distance from the primary heat source housing.The second and third 3-way connectors are located between the primary heat source housing and the domestic hot water storage housing.

[0016] In this case, when the primary heat source housing and the domestic hot water storage housing are arranged at a distance from each other, the primary heat source drain line and the primary heat source inlet line are at least partially accessible from the outside. This makes the installation of the 3-way connectors described above particularly easy, as no modifications to the primary heat source housing or the domestic hot water storage housing are required.

[0017] According to a preferred, alternative embodiment of the central heating system, a water-water heat exchanger, in particular a plate heat exchanger, is provided, in particular embodied as a separate component, wherein the branch flow circuit inflow line of the branch flow circuit is fluidly connected to and / or connected to a first side of the water-water heat exchanger, such that the heat transfer fluid can be supplied to the first side via the branch flow circuit inflow line. The branch flow circuit outflow line of the branch flow circuit is fluidly connected to and / or connected to the first side, such that the heat transfer fluid can be discharged from the first side via the branch flow circuit outflow line.A domestic water outlet line is fluidically connected and / or connected accordingly, on the one hand, to the domestic water storage tank and, on the other hand, to a second side of the water-to-water heat exchanger, so that the domestic water can be fed from the domestic water storage tank to the second side via the domestic water outlet line, in particular with the aid of a domestic water pump. A domestic water inlet line is fluidically connected and / or connected accordingly, on the one hand, to the domestic water storage tank and, on the other hand, to the second side, so that the domestic water can be fed from the second side via the domestic water inlet line. Preferably, a check valve opening towards the domestic water pump is fluidically arranged upstream of the domestic water pump.

[0018] The energy provided by the heat pump can be transferred to the domestic hot water via the water-to-water heat exchanger. The water-to-water heat exchanger can then be optimized to match the flow rates of the heat transfer fluid through the heat pump and through the first side of the water-to-water heat exchanger to ensure the best possible heat transfer to the domestic hot water.

[0019] Advantageously, a hot water pipe is fluidically connected to the domestic water drain line and / or connected to the domestic water drain line. A cold water pipe is preferably fluidically connected to the domestic water inlet line and / or connected to the domestic water inlet line.

[0020] Heated domestic water can be drawn from the hot water tank via the hot water pipe for subsequent use, such as showering. However, if the heated domestic water is not at the desired temperature, the domestic water that is still too cold is fed to the second side of the water-to-water heat exchanger, where it is heated using the energy provided by the heat pump. The domestic water heated in the second side of the water-to-water heat exchanger can then be fed back into the domestic water tank, possibly with the addition of fresh, cold domestic water supplied via the cold water pipe.

[0021] Further preferably, the primary heat source and the domestic hot water storage tank have a common integral housing, wherein the primary heat source outflow line and the primary heat source inflow line are arranged, in particular each completely, within the integral housing.

[0022] The above-described variant of the central heating system with the separate water-to-water heat exchanger is particularly suitable when the primary heat source and the domestic hot water storage tank share a common integral housing, and a subsequent connection of the heat pump between the primary heat source and the domestic hot water storage tank is not possible or only possible with disproportionate effort, i.e., modifications to such an integral housing. In other words, retrofitting a heat pump to a central heating system is possible even when the primary heat source and the domestic hot water storage tank share a common integral housing.

[0023] Preferably, the heating pump is assigned to the water-air heat exchanger, the circulation pump to the heat pump and the heat source pump to the primary heat source, namely arranged in a fluidically arranged area of ​​the pipe system assigned to the respective unit or in a partial pipe area having the respective unit.

[0024] Thus, the heat pump can be used to adjust the mass flow of heat transfer fluid conveyed through the water-to-air heat exchanger, the circulation pump can be used to adjust the mass flow of heat transfer fluid conveyed through the heat pump, and the heat source pump can be used to adjust the mass flow of heat transfer fluid conveyed through the primary heat source. However, the heat pump and the heat source pump, in particular, are optional, since, with the appropriate switching of the valves described above, the flow through the water-to-air heat exchanger and / or the primary heat source can also be generated, for example, solely by the circulation pump.

[0025] According to a further embodiment of the central heating system, a central heating control and / or regulating device is connected to the primary heat source for its control and / or regulation. A temperature sensor is arranged in a lower area of ​​the domestic hot water storage tank (viewed vertically) or adjacent to this lower area of ​​the domestic hot water storage tank (viewed vertically) for determining the actual domestic hot water temperature. The temperature sensor is connected to a heat pump control and / or regulating device for control, signal, and / or data transmission. The heat pump is connected to the heat pump control and / or regulating device (viewed vertically). The heat pump control and / or regulating device is designed and / or constructed such that the heat pump can be controlled and / or regulated depending on the determined actual domestic hot water temperature, which will be explained in more detail below.

[0026] In this way, the temperature of the domestic water can be controlled and / or regulated particularly well using 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 storage tank, the heat pump can initially be controlled and / or regulated particularly quickly, in particular without a significant time delay, especially when fresh and therefore cold or colder domestic water is fed back into the domestic water storage tank due to domestic water being drawn from the domestic water storage tank (e.g., for a domestic shower) by filling the domestic water storage tank with fresh domestic water. The supplied - fresh - domestic water flows around the temperature sensor before it mixes with the rest of the domestic water still present in the domestic water storage tank, some of which has already been heated.The lower area of ​​the domestic hot water tank, viewed vertically, is preferably formed in a lower half, in particular a lower third, in particular a lower quarter, of the total height of the domestic hot water tank. The first temperature sensor is then provided or arranged in particular in this previously mentioned or defined lower area of ​​the domestic hot water tank.

[0027] Preferably, 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.

[0028] By opening the inlet valve, fresh domestic water, especially drinking water, can be supplied to the domestic water storage tank via the cold water line, the domestic water inlet line, and the inlet connection. Adjacent to the domestic water storage tank, the domestic water inlet line is functionally assigned to the condensate storage tank, as the domestic water temperatures here are comparable to those at the same level within the domestic water storage tank. The temperature sensor can also be installed on the domestic water inlet line without great effort, as the domestic water storage tank itself does not require any structural modifications, and the temperature sensor can still be installed, especially with direct contact to the supplied domestic water.In particular, a section of the domestic water supply line can also be cut out and replaced, in particular, by a T-piece, in which case the temperature sensor is then arranged in a branch of the T-piece and preferably connected to the T-piece with a sealing cap. On the other hand, the T-piece could also be interposed in the domestic water supply line in such a way that a section of the domestic water supply line is connected to the branch of the T-piece, so that the temperature sensor is still arranged at one of the two parallel connections of the T-piece and closes this connection, and the temperature sensor then preferably penetrates the T-piece completely. On the other hand, it is also conceivable and possible to arrange the temperature sensor externally on or in a housing / jacket area of ​​the domestic water storage tank or the domestic water supply line.

[0029] The aforementioned temperature sensor is advantageously designed as a first temperature sensor for determining a first actual domestic water temperature, with a second temperature sensor arranged in a—vertically viewed—middle or upper region of the domestic water storage tank 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 for control, signal, and / or data transmission. The central heating control and / or regulating device is designed and / or constructed such 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 for control purposes” used here and elsewhere can and does always include a signal and / or data connection.

[0030] The middle or upper area of ​​the domestic hot water tank, viewed vertically, is preferably located in the upper half, the entire height of the domestic hot water tank, or is designed 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 the central heating control and / or regulating device and those carried out by 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, is subsequently integrated into the central heating system, since the central heating control and / or regulating device then does not need to be modified.On the other hand, it is also conceivable that the central heating control and / or regulation device and the heat pump control and / or regulation device are or will be combined in a common control and / or regulation device, which is advantageous if the entire central heating system is designed at the same time.

[0031] Optimal control and / or regulation of the entire central heating system, particularly with regard to minimizing fuel requirements for the primary energy source and / or avoiding cost-intensive structural designs, is therefore also made possible by the specific arrangement of the first temperature sensor relative to the second temperature sensor. The first temperature sensor is arranged below the second temperature sensor, essentially viewed vertically. Due to the temperature stratification of the domestic water that develops within the domestic water storage 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 temperature, in particular a decrease in 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 heat quantity provided by the heat pump is no longer sufficient, in particular to cover the demand for heating the domestic hot water storage tank, so that the fuel requirement for the primary heat source can be minimized or at least reduced. In particular, the first temperature sensor - viewed vertically - is located in the lower half of the domestic hot water storage tank and the second temperature sensor - viewed vertically - is located in the upper half of the domestic hot water storage tank, respectively, at the corresponding height or in the corresponding area (lower half orupper half) of the total vertical height of the domestic hot water tank.

[0032] Further preferably, the heat pump control and / or regulating device is designed and / or configured 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, in particular, calculated by the heat pump control and / or regulating device, falls below a first limit temperature. The central heating control and / or regulating device is designed and / or configured 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.

[0033] By introducing the first and second limit temperatures, the heat pump can be operated preferentially in a particularly simple manner. For this purpose, in particular the first and second limit temperatures are selected accordingly or set to a respective 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 selecting the respective limit temperatures accordingly, a distinction is made between the preferably independently implemented oroperating central heating control and / or regulating device and the heat pump control and / or regulating device, an indirect dependency of these two control and / or regulating devices on each other is then achieved or realized, or in particular it can also be selected and / or determined from when, for example, the primary heat source is switched on or additionally activated to the heat pump.

[0034] In a further advantageous embodiment of the central heating system, the output of the heat pump can be continuously adjusted, 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.

[0035] 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 low 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 to date, however, the only heat pumps available were those that could either not be operated at all or only at maximum output, which then led to the heat pump being used less frequently. In order to then enable the heat pump to be used more frequently, heat pumps with lower outputs 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 hot water storage tanks.

[0036] When the heat transfer fluid is fed to the primary heat source, the entire heat transfer fluid heated by the heat pump can also be fed to the primary heat source via the heat pump's drain line. This further reduces the fuel requirement of the primary heat source, as the primary heat source does not need to be activated and / or operated at all or only rarely due to the relatively high temperature of the heat transfer fluid fed to the primary heat source.

[0037] The piping system preferably comprises at least one 4 / 2-way valve arranged and / or functionally effective between the first 3 / 2-way valve or the first 3-way connector on the one hand and the water-air heat exchanger and the heat pump on the other, with the aid of which the heat transfer fluid can be directed and / or guided to the water-air heat exchanger or past the water-air heat exchanger to the heat pump. For example, a combination of a 3 / 2-way valve with a 3-way connector, which are each fluidically connected to one another via a connection, also functions functionally like the aforementioned 4 / 2-way valve. This latter combination or design then has four connections and two switching positions, namely of the 3 / 2-way valve, so that two different flow paths between the four connections can be realized accordingly.

[0038] By means of the aforementioned, particularly functionally designed 4 / 2-way valve and the first 3 / 2-way valve, different flow circuits or different flow paths for the heat transfer fluid can then be realized - depending on the respective valve position - in particular as follows:

[0039] Thus, in a branch flow circuit (shown in Fig. 1 a), a flow of the heat transfer fluid from the heat pump, via the circulation pump, via the first 3-way connecting piece, via the branch flow circuit inflow line, via the second 3 / 2-way connecting piece, via the domestic hot water tank or via the heating line, via the third 3-way connecting piece, via the branch flow circuit outflow line, via the first 3 / 2-way valve in its first switching position and via the 4 / 2-way valve and back to the heat pump can be realized. Furthermore, with the help of the branch flow circuit, a flow of the heat transfer fluid is also possible from the heat pump, via the circulation pump, via the first 3-way connecting piece, via the branch flow circuit inlet line, via the second 3-way connecting piece, via the domestic hot water tank orvia the heating line, via the third 3-way connector, via the branch flow circuit drain line, via the first 3 / 2-way valve in its first switching position, via the 4 / 2-way valve, via the water-air heat exchanger, and back to the heat pump. The flow paths described above depend in particular on the switching position of the 4 / 2-way valve, especially the second and third 3 / 2-way valves that form the 4 / 2-way valve.

[0040] In a further branch flow circuit (shown in Fig. 1 b), a flow of the heat transfer fluid from the heat pump, via the circulation pump, via the first 3 / 2-way valve in its first switching position, via the branch flow circuit inflow line, via the second 3-way connecting piece, via the domestic hot water storage tank or via the heating line, via the third 3-way connecting piece, via the branch flow circuit drain line, via the first 3-way connecting piece, as well as via the 4 / 2-way valve and back to the heat pump is possible. Furthermore, a flow of the heat transfer fluid from the heat pump, via the circulation pump, via the first 3 / 2-way valve in its first switching position, via the branch flow circuit inflow line, via the second 3-way connecting piece, via the domestic hot water storage tank orvia the heating line, via the third 3-way connector, via the branch flow circuit drain line, via the first 3-way connector, via the 4 / 2-way valve, via the water-air heat exchanger, and back to the heat pump. The previously described flow paths depend in particular on the switching position of the 4 / 2-way valve, especially the second and third 3 / 2-way valves that form the 4 / 2-way valve.

[0041] For a further branch flow circuit (shown in Fig. 2a), a flow of the heat transfer fluid from the heat pump, via the circulation pump, via the first 3-way connector, via the branch flow circuit inflow line, via the first side of the water-water heat exchanger, via the branch flow circuit outflow line, via the first 3 / 2-way valve in its first switching position, via the 4 / 2-way valve and back to the heat pump can be realized. Furthermore, with the help of the branch flow circuit, a flow of the heat transfer fluid from the heat pump, via the circulation pump, via the first 3-way connecting piece, via the branch flow circuit inflow line, via the first side of the water-water heat exchanger, via the branch flow circuit outflow line, via the first 3 / 2-way valve in its first switching position, via the 4 / 2-way valve, via the water-air heat exchanger and back to the heat pump can be realized.The flow paths described above depend in particular on the switching position of the 4 / 2-way valve, in particular the second and third 3 / 2-way valves forming the 4 / 2-way valve.

[0042] With the help of a further branch flow circuit (shown in Fig. 2b), a flow of the heat transfer fluid from the heat pump, via the circulation pump, via the first 3 / 2-way valve in its first switching position, via the branch flow circuit inflow line, via the first side of the water-water heat exchanger, via the branch flow circuit outflow line, via the first 3-way connecting piece, via the 4 / 2-way valve and back to the heat pump can be realized. Furthermore, with the help of the branch flow circuit, a flow of the heat transfer fluid from the heat pump, via the circulation pump, via the first 3 / 2-way valve in its first switching position, via the branch flow circuit inflow line, via the first side of the water-water heat exchanger, via the branch flow circuit outflow line, via the first 3-way connecting piece, via the 4 / 2-way valve, via the water-air heat exchanger and back to the heat pump can be realized.The flow paths described above depend in particular on the switching position of the 4 / 2-way valve, in particular the second and third 3 / 2-way valves forming the 4 / 2-way valve.

[0043] In a first heating circuit, a flow of the heat transfer fluid from the heat pump, via the circulation pump, via the first 3-way connecting piece (cf. Fig. 1a and 2a) or the first 3 / 2-way valve (cf. Fig. 1b and 2b), in particular via the primary heat source 3 / 2-way valve, via the primary heat source, via the first 3 / 2-way valve (cf. Fig. 1a and 2a) or the first 3-way connecting piece (cf. Fig. 1b and 2b), via the 4 / 2-way valve, via the water-air heat exchanger and back to the heat pump can be realized.

[0044] In a further, second heating circuit, in particular partly without the valves mentioned above, a flow of the heat transfer fluid from the primary heat source, via the domestic hot water storage tank or via the heating line, then in particular via the primary heat source 3 / 2-way valve, via the heat source pump, which is in particular then activated, and back to the primary heat source can be realized (cf. Fig.1a, Fig.1b, Fig.2a and Fig.2b).

[0045] According to a preferred embodiment of the central heating system, the piping system comprises a second and a third 3 / 2-way valve, each with three connections and two switching positions, namely a second 3 / 2-way valve, in particular arranged in the heat exchanger inflow line and / or interposed therein, and a third 3 / 2-way valve, in particular arranged in the heat pump inflow line and / or interposed therein. The second 3 / 2-way valve is fluidly connected to the first 3 / 2-way valve (cf. Figs. 1a and 2a) or the first 3-way connector (cf. Figs. 1b and 2b), the water-air heat exchanger, and the third 3 / 2-way valve. The third 3 / 2-way valve is fluidly connected to the water-air heat exchanger, the second 3 / 2-way valve, and the heat pump.The second 3 / 2-way valve enables the heat transfer fluid to flow either from the first 3 / 2-way valve or from the first 3-way connector to the water-air heat exchanger or to the third 3 / 2-way valve. The third 3 / 2-way valve enables the heat transfer fluid to flow either from the water-air heat exchanger or from the second 3 / 2-way valve to the heat pump. The second and third 3 / 2-way valves, as well as a corresponding 4 / 2-way valve, can be used to create the first and second branch flow circuits described above and the first heating circuit. 3 / 2-way valves are also inexpensive to procure and easy to control and / or regulate. The 3 / 2-way valves mentioned here 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 3 / 2-way valves are then installed in such a way that the 3 / 2-way valves do not need to be energized for a longer period of time during operation of the central heating system, thus also saving energy.

[0046] Preferably, at least two, in particular all of the aforementioned, elements and / or components from the group of the following elements and / or components, namely 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 4 / 2-way valve, in particular the second 3 / 2-way valve and the third 3 / 2-way valve, and the respective associated connections are arranged and / or formed on a first hydraulic module forming a common structural unit. In particular, the circulation pump could also be arranged outside the first hydraulic module, e.g., integrated into the heat pump, or additionally arranged in the first hydraulic module.

[0047] According to a further advantageous embodiment of the central heating system, at least two, in particular all of the above-mentioned, elements and / or components and respective associated connections from the group of the following elements and / or components, namely the heat exchanger inflow line at least in sections, the branch flow circuit inflow line at least in sections, the branch flow circuit outflow line at least in sections, the heat pump outflow line at least in sections, the first 3-way connecting piece and the first 3 / 2-way valve, are arranged and / or formed on a second hydraulic module forming a common structural unit.

[0048] According to a further, particularly preferred embodiment of the central heating system, at least two, in particular all of the above-mentioned, elements and / or components and respective associated connections from the group of the following elements and / or components, namely the branch flow circuit inflow line at least in sections, the branch flow circuit outflow line at least in sections, the water-water heat exchanger, the domestic water inflow line at least in sections, the domestic water outflow line at least in sections and the domestic water pump are arranged and / or formed on a third hydraulic module forming a common structural unit.

[0049] Using such hydraulic modules, the assembly and / or construction of the central heating system can be greatly simplified. Complex assembly can be avoided because the structural shape of the hydraulic modules predetermines certain arrangements of elements and / or components in relation to one another or makes them simple and easy for the installer to identify. The hydraulic module can then advantageously be pre-assembled, for example, in a factory or by a heating engineer, so that the assembly time for the end customer who operates the central heating system can be significantly reduced. The multiple hydraulic modules enable different configurations of the central heating system to be implemented, e.g. a variant with the primary heat source housing spaced apart from the domestic hot water storage tank housing, without a water-water heat exchanger, whereby this variant then has the first and second hydraulic module.A second variant of the central heating system, with the shared integral housing for the primary heat source and the domestic hot water storage tank, and with the water-to-water heat exchanger, preferably has all three hydraulic modules. Only the first hydraulic module can be used, for example, in a variant of the central heating system in which the domestic hot water storage tank is connected to the primary heat source via a separate heating circuit with a separate pump.

[0050] 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 heat pump for control and / or regulation of the heating pump and / or the heat pump control and / or regulating device is connected to the circulation pump for control and / or regulation of the heating pump and / or the heat pump control and / or regulating device is connected to the circulation pump for control and / or regulation of the heating pump and / or the heat pump control and / or regulating device is connected to the domestic water pump for control and / or regulation of the domestic water pump and / or the central heating control and / or regulating device is connected to the heat source pump for control and / or regulation of the heating source pump and / or the heat pump control and / or regulating device is connected to the heat source pump for control and / or regulation of the heating pumpof the first 3 / 2-way valve is connected for control purposes to the first 3 / 2-way valve and / or the central heating control and / or regulating device for controlling and / or regulating the primary heat source 3 / 2-way valve is connected for control purposes to the primary heat source 3 / 2-way valve and / or the heat pump control and / or regulating device for controlling and / or regulating the 4 / 2-way valve, in particular the second and third 3 / 2-way valve, is connected for control purposes to the 4 / 2-way valve and / or the heat pump control and / or regulating device is connected for control purposes, signal purposes and / or data purposes to an outside temperature sensor for determining an outside temperature.

[0051] Thus, essential elements and / or components of the central heating system can be controlled and / or regulated by means of the heat pump control and / or regulation device. These elements and / or components can then also be controlled and / or regulated accordingly depending on the respective output of the heat pump. This particularly takes into account the fact that the heat pump is primarily operated as a primary heat source and that the primary heat source can only be activated and / or operated when the heat provided by the heat pump is no longer sufficient in a particular application to cover the heat demand of the central heating system, in particular the heat demand of the water-air heat exchanger and / or the domestic hot water storage tank. The energy supply to the heat pump control and / or regulation device could then also be provided directly via an electrical grid, for example; this should also be noted.

[0052] 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 21.

[0053] One aspect of the invention then essentially lies in the fact that the first 3 / 2-way valve is switched to a first switching position, thus enabling a flow of the heat transfer fluid from the branch flow circuit outflow line to a region of the heat exchanger inflow line fluidically facing the water-to-air heat exchanger and / or the heat pump, in order to supply the heat transfer fluid to the water-to-air heat exchanger and / or the heat pump from a primary heat source inflow line or from the first side of the water-to-water heat exchanger, or that the first 3 / 2-way valve is switched to a second switching position, thus enabling a flow of the heat transfer fluid from a region of the heat exchanger inflow line fluidically upstream of the first 3 / 2-way valve to the region of the heat exchanger inflow line fluidically facing the water-to-air heat exchanger and / or the heat pump,to supply the heat transfer fluid to the water-to-air heat exchanger and / or the heat pump from a primary heat source discharge line and thus bypass the heating line and / or the water-to-water heat exchanger.

[0054] The object underlying the invention is also achieved by a method for operating and / or controlling and / or regulating a central heating system having the features of patent claim 22.

[0055] One aspect of the invention then essentially lies in the fact that the first 3 / 2-way valve is switched into a first switching position and thus a flow of the heat transfer fluid from a region of the heat pump discharge line in terms of flow upstream of the first 3 / 2-way valve into a branch flow circuit inflow line is enabled in order to supply the heat transfer fluid from the heat pump to a heating line or the first side of a water-water heat exchanger, or that the first 3 / 2-way valve is switched into a second switching position and thus a flow of the heat transfer fluid from the region of the heat pump discharge line in terms of flow upstream of the first 3 / 2-way valve to a primary heat source inflow line is enabled in order to supply the heat transfer fluid to the primary heat source and in particular thus to bypass the heating line and / or the water-water heat exchanger in terms of flow.

[0056] Whether the domestic water is heated using the energy provided by the heat pump can be implemented particularly easily in these two control methods, namely by switching the respective first 3 / 2-way valve to its first switching position. Preferably, the actuator of this respective first 3 / 2-way valve must then be energized. In its "de-energized" state, the first 3 / 2-way valve is preferably in its second switching position. Check valves are also provided in certain lines or flow connections to prevent backflow of the heat transfer fluid; this should also be noted. In this regard, particular reference is also made to the figures.

[0057] Preferably, the first actual domestic water temperature in a (vertically viewed) lower area of ​​the domestic water storage tank is measured, determined, and / or calculated using the first temperature sensor, in particular by a heat pump control and / or regulating device. The heat pump is controlled and / or regulated by a heat pump control and / or regulating device depending on the determined actual domestic water temperature.

[0058] In this way, the temperature of the domestic water is particularly effectively controlled and / or regulated by the heat pump and the heat pump control and / or regulation device. By arranging the temperature sensor in the lower area of ​​the domestic water storage tank (viewed vertically), the heat pump is activated and / or regulated particularly quickly, in particular without a significant time delay when fresh and therefore particularly cold domestic water is then fed back into the domestic water storage tank due to the withdrawal of domestic water from the domestic water storage tank, e.g., for a shower. This is particularly true because the supplied domestic water flows around the temperature sensor before it mixes or blends with the rest of the domestic water still present in the domestic water storage tank.

[0059] According to an advantageous embodiment of the method, the first actual domestic water temperature is transmitted to the heat pump control and / or regulating device and / or determined and / or calculated by means of the heat pump control and / or regulating device. The second, preferably average, actual domestic water temperature is measured, determined and / or calculated by means of the second temperature sensor in a - vertically viewed - 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.

[0060] The specific arrangement of the two temperature sensors ensures optimal control and / or regulation of the entire central heating system with a view to minimizing the fuel requirement for the primary heat source. Because the first temperature sensor determines a lower actual domestic water temperature than the second temperature sensor due to the temperature stratification of the domestic water in the domestic water storage tank, the entire central heating system can be optimally controlled, even with independently implemented central heating control and / or regulation devices and heat pump control and / or regulation devices, with the heat pump being preferably operated upstream of the primary heat source. This minimizes or reduces the fuel requirement for the primary heat source.In this case, the first temperature sensor - viewed vertically - is provided and / or arranged in particular in the lower half and the second temperature sensor - viewed vertically - in the upper half of the domestic hot water tank or in the corresponding lower or upper vertical area of ​​the total vertical height of the domestic hot water tank.

[0061] Further preferably, the heat pump is operated and / or activated with the aid of the heat pump control and / or regulating device for heating the heat transfer fluid and the first 3 / 2-way valve is switched into its first switching position with the aid of the heat pump control and / or regulating device 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 is operated and / or activated with the aid of the central heating control and / or regulating device for heating the heat transfer fluid and in particular the primary heat source 3 / 2-way valve is switched into a first switching position with the aid of the central heating control and / or regulating device for connecting the heating line to the primary heat source via the primary heat source inflow line and / or the heat source pump is operated and / or activated with the aid of the central heating control and / or regulating device 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.

[0062] 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.

[0063] Preferably, the first and the second limit temperature are 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, in particular the primary heat source 3 / 2-way valve is switched to its first switching position, and in particular the heat source pump is only operated and / or activated when a heat requirement of the domestic hot water storage tank exceeds a heat quantity 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 is no longer sufficient on its own to heat the domestic hot water to the desired temperature.

[0064] This ensures optimal utilization of the heat pump's performance, and the primary energy requirement for the central heating system's primary heat source—namely, the fuel requirement—is further reduced. The heat requirement of the domestic hot water storage tank is preferably determined indirectly by selecting the threshold temperatures in relation to other relevant parameters, such as the size of the domestic hot water storage tank.

[0065] Advantageously, the heat pump and / or the circulation pump are controlled and / or regulated by means of the heat pump control and / or regulation device, in particular additionally, 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.

[0066] The heat pump has an internal fluid circuit through which a refrigerant flows. This refrigerant evaporates at low pressure while heat is added. After being compressed to a higher pressure, it condenses again and releases heat to the heat transfer fluid. This process requires an evaporator, a compressor, a condenser, and a throttle. The gaseous refrigerant is compressed in the compressor and, in particular, heats up in the process. The hot, compressed refrigerant then releases its heat to the heat transfer fluid in the condenser. The compressed refrigerant cools down and, in particular, condenses at least partially into liquid refrigerant. As it subsequently flows through the throttle, the refrigerant is expanded and, in particular, further cooled partially. The then cold refrigerant then flows through the evaporator, which is usually located outside the building.In the evaporator, the cold refrigerant is heated, for example, by groundwater or the outside air, and evaporates in the process. The refrigerant is then fed back to the compressor, and the process begins, in particular, anew. Preferably, the heat pump is designed as an air-to-water heat pump, in which the refrigerant in the evaporator is heated by the outside air. Further preferably, the evaporator, the compressor, the condenser, and the throttle are designed as a single structural unit, with the heat pump inlet line and the heat pump outlet line being connected, in particular, to the heat pump condenser.

[0067] According to a preferred embodiment of the method, the primary heat source and / or the heat source pump 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 develops within or in the region of the primary heat source - and / or as a function of a second target heat transfer fluid temperature - which is predetermined for the inner region of the primary heat source.

[0068] 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 within or in the vicinity of the primary heat source to determine the second actual heat transfer fluid temperature. Alternatively, it is also 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.

[0069] Further preferably, the second target heat transfer fluid temperature is below the first target heat transfer fluid temperature or is set accordingly such that the primary heat source is operated and / or activated with the aid of the central heating control and / or regulating device for heating the heat transfer fluid only when a heat requirement of the central heating system, in particular a heat requirement of the water-air heat exchanger and / or the domestic hot water storage tank, exceeds a heat quantity that can be provided by means of the heat pump at maximum output of the heat pump.

[0070] This allows the heat pump to be preferentially operated as the primary heat source even when the domestic water in the domestic hot water tank is not being heated by the heat transfer fluid and the heat transfer fluid is flowing through the aforementioned first heating circuit. Overall, particularly 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 water-air heat exchanger and / or the domestic hot water tank, is preferably determined indirectly, particularly via the selection / setting of the two target heat transfer fluid temperatures. Such a heat requirement of the water-air heat exchanger also depends, in particular, on the desired room temperature of a room to be heated by the water-air heat exchanger.It is conceivable that such a desired room temperature is selected by a user of the room to be heated and is subsequently available in the heat pump control and / or regulating 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. There are now a multitude of possibilities for advantageously 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 this regard, reference is initially made to the patent claims 1 and 2, respectively, and to the patent claims subordinate to patent claims 21 and 22, respectively.In the following, several preferred embodiments of the central heating system according to the invention and of the method according to the invention for operating and / or controlling and / or regulating the central heating system will be explained and described in more detail with reference to the following drawing and the associated description. The drawing shows:

[0071] Fig.1a shows a schematic representation of a hydraulic circuit diagram of a first

[0072] Example of the central heating system,

[0073] Fig.1b shows a schematic representation of a hydraulic circuit diagram of a second

[0074] Example of the central heating system,

[0075] Fig.2a shows a schematic representation of a hydraulic circuit diagram of a third

[0076] Example of the central heating system,

[0077] Fig.2b shows a schematic representation of a hydraulic circuit diagram of a fourth

[0078] Example of the central heating system,

[0079] Fig.3a shows a schematic representation of a domestic hot water storage tank for use in the first or second embodiment of the central heating system in an enlarged side view,

[0080] Fig.3b shows a schematic representation of a domestic hot water storage tank for use in the third or fourth embodiment of the central heating system in an enlarged side view,

[0081] Fig.4 shows a schematic representation of a flow diagram for a method for operating and / or controlling and / or regulating a heat pump of the central heating system according to Fig.1a, Fig.1b, Fig.2a or Fig.2b, Fig.5 shows a schematic representation of a flow diagram for a method for operating and / or controlling and / or regulating a primary heat source of the central heating system according to Fig.1a, Fig.1b, Fig.2a or Fig.2b,

[0082] 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

[0083] 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 on the outside temperature, wherein the first limit temperature is greater than the second limit temperature.

[0084] Fig. 1a, Fig. 1b, Fig. 2a and Fig. 2b each show a central heating system 1 with at least one primary heat source 2 operable with the aid of fuels, in particular a gas boiler or a heating boiler, with at least one electrically operated heat pump 3, with at least one water-air heat exchanger 4, preferably a heater or a radiator for heating a building, and with at least one domestic hot water storage tank 5, in particular a boiler, for the temporary storage of domestic hot water 11. The water-air heat exchanger 4 could also be designed by means of or as an underfloor heating system. It should also be noted here that the term "primary heat source 2 operable with fuels" also includes, for example, a "heating boiler", in particular an oil-fired oil boiler or a gas boiler. Preferably, however, a commercially available, so-called gas boiler is considered here, such as this onein an apartment building, used separately in each apartment.

[0085] 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. By means of a pipe system 7 and with the aid of at least one pump 8, 9, 9b, in particular a heating pump 8, a circulation pump 9 and / or a heat source pump 9b, the heat transfer fluid 6 can be conveyed for heating by the heat pump 3 and / or, in particular, for heating by the primary heat source 2. A heat exchanger inlet line LWT, ZU of the pipe system 7 is fluidically connected and / or connected accordingly to the primary heat source 2 on the one hand and to the water-air heat exchanger 4 on the other hand, so that the heat transfer fluid 6 is supplied through the heat exchanger inlet line LWT, ZU can be fed to the water-air heat exchanger 4.

[0086] A heat pump inlet line L W p,zu of the pipe system 7 is fluidically connected and / or connected accordingly to the water-air heat exchanger 4 on the one hand and to the heat pump 3 on the other hand, so that the heat transfer fluid 6 is supplied through the heat pump inlet line L W p, zu can be fed to the heat pump 3.

[0087] A heat pump drain line L W p, ab of the pipe system 7 is fluidically connected and / or connected accordingly on the one hand to the heat pump 3 and on the other hand to the primary heat source 2, so that the heat transfer fluid 6 can be supplied through the heat pump discharge line LWP, ab the primary heat source 2.

[0088] In the first, second, third, and fourth exemplary embodiments of the central heating system 1 according to Fig. 1a, Fig. 1b, Fig. 2a, and Fig. 2b, the water-air heat exchanger 4 and the heat pump 3 are connected, or can be connected, in series with respect to the primary heat source 2, particularly in terms of flow. The heat transfer fluid 6 can be pumped through both the heat pump 3 and the water-air heat exchanger 4 by means of the circulation pump 9, so that the use of the heat pump 8 is not absolutely necessary. The heat pump 8 is therefore shown as optional with dashed lines. The same applies analogously to the heat source pump 9b, which is also shown as optional with dashed lines, since under certain circumstances one pump, namely in particular the circulation pump 9, is or can be sufficient to implement the relevant flow circuits, which will be explained in more detail later.

[0089] A - first - 3 / 2-way valve 21.1 is according to Fig.1 a and Fig.2a in the heat exchanger inlet line LWT, ZU arranged and / or interposed here. A first 3-way connector 26.1 is arranged and / or interposed here in the heat pump drain line LWP, as shown in Figs. 1a and 4, Fig. 2a.

[0090] The - first - 3-way connecting piece 26.1 is according to Fig.1 b and Fig.2b according to the embodiments shown there in the heat exchanger inflow line L W T, ZU arranged and / or interposed here. The first 3 / 2-way valve 21.1 is arranged in the heat pump drain line L according to Fig.1 b and Fig.2b. WP , arranged and / or interposed here.

[0091] A 3-way connector serves to fluidically connect three lines to one another and thus has three connections, one of which can also be referred to as a branch. A 3 / 2-way valve also has three connections, one of which can be referred to as a branch, whereby two different flow paths can also be realized through the 3 / 2-way valve by means of a 3 / 2-way valve. A 3 / 2-way valve can be switched into two switching positions. By means of a connection or branch of the first 3 / 2-way valve 21.1 and a connection or branch of the first 3-way connector 26.1, a branch flow circuit KAB of the line system 7 is or can be formed here, as shown in Fig. 1a, Fig. 1b, Fig. 2a and Fig. 2b.The heat transfer fluid 6 can be pumped through the branch flow circuit KAB by means of at least one pump 8, 9, 9b, and the domestic water 11 can be heated with the aid of the heat transfer fluid 6 flowing through the branch flow circuit KAB. In a first switching position of the first 3 / 2-way valve 21.1, the heat transfer fluid 6 can be pumped through the branch flow circuit KAB, and in a second switching position of the first 3 / 2-way valve 21.1, the flow of the heat transfer fluid 6 through the branch flow circuit KAB can be avoided, in particular at least partially. The flow path through the first 3 / 2-way valve 21.1 that can be realized in the first switching position of the first 3 / 2-way valve 21.1 is symbolized by the curved arrow and a Roman numeral I. The flow path through the first 3 / 2-way valve 21.1 that can be realized in the second switching position of the first 3 / 2-way valve 21.1 is symbolized by the straight arrow and a Roman numeral II.

[0092] A heating line LHZ is arranged and / or formed within the domestic hot water storage tank 5, within a wall of the domestic hot water storage tank 5 and / or externally on the wall of the domestic hot water storage tank 5, so that when the heat transfer fluid 6 flows through the heating line LHZ, the domestic hot water 11 then present in the domestic hot water storage tank 5 can be heated by means of the heat transfer fluid 6.

[0093] A primary heat source drain line L PQ , a b of the pipe system 7 is fluidically connected and / or connected accordingly to the primary heat source 2 on the one hand and to the heating line LHZ on the other hand, so that the heat transfer fluid 6 is discharged through the primary heat source discharge line L PQ , ab the heating line LHZ can be supplied A primary heat source supply line l_ PQ , zuof the pipe system 7 is fluidically connected on the one hand to the heating pipe LHZ and on the other hand to the primary heat source 2 and / or is connected accordingly, so that the heat transfer fluid 6 is supplied through the primary heat source inflow pipe LQ, ZU the primary heat source 2. A second heating circuit, already mentioned at the beginning, with a flow of the heat transfer fluid 6 from the primary heat source 2, via the domestic hot water tank 5, in particular via a primary heat source 3 / 2-way valve 21. G, via the heat source pump 9b and back to the primary heat source 2, is thus also connected in particular to the primary heat source discharge line LPQ, by means of the heating line LHZ and to the primary heat source inflow line L PQ , zu feasible.

[0094] The domestic hot water tank 5, which can be used in both the first embodiment of the central heating system 1 according to Fig. 1a and the second embodiment of the central heating system 1 according to Fig. 1b, is shown schematically enlarged in Fig. 3a. The domestic hot water tank 5, which can be used in both the third embodiment of the central heating system 1 according to Fig. 2a and the fourth embodiment of the central heating system 1 according to Fig. 2b, is shown schematically enlarged in Fig. 3b, but here with a slightly modified connection situation compared to Fig. 3a.

[0095] The heat transfer from the heat transfer fluid 6 to the domestic water 11 takes place here in particular by means of the heating line LHZ, which preferably runs in a helical shape through the domestic water tank 5 and through which the heat transfer fluid 6 can be passed. The heating line LHZ could also run in a different way, e.g. in a curved shape, through the domestic water tank 5. Alternatively, it is conceivable that a preferably meandering heating line is arranged and / or formed in a wall of the domestic water tank 5 in order to enable the heat transfer from the heat transfer fluid 6 to the domestic water 11 by the heat transfer fluid 6 flowing through this heating line. Furthermore, heating lines for this heat transfer could be arranged externally on the wall of the domestic water tank 5, wherein these lines are then insulated accordingly, in particular on a side facing away from the domestic water tank 5.

[0096] The heat exchanger inlet line LWT,zu is connected to the primary heat source drain line L PQ , ab fluidically connected and / or to the primary heat source discharge line LQ, a b connected fluidically. The heat pump drain line L W p, ab is connected to the primary heat source inflow line LQ, ZU fluidically connected and / or to the primary heat source inflow line L PQ , zufluidically connected, in particular with the aid of the primary heat source 3 / 2-way valve 21.G. By means of the primary heat source 3 / 2-way valve 21.G in a first switching position, the heat transfer fluid 6 coming from the domestic hot water tank 5 can be supplied to the primary heat source 2. By means of such a primary heat source 3 / 2-way valve 21.G in a second switching position, the heat transfer fluid 6 coming from the heat pump 3 can be supplied to the primary heat source 2. The above statements essentially apply to all embodiments of Fig. 1a, 1b, 2a and 2b. In a conventional central heating system 1 without a heat pump 3, in particular to which the heat pump 3 shown here has been retrofitted accordingly, the heat transfer fluid coming from a water-air heat exchanger can be supplied to the primary heat source by means of such a primary heat source 3 / 2-way valve in a second switching position. The first switching position of the primary heat source 3 / 2-way valve 21 .The flow path through the primary heat source 3 / 2-way valve 21. G that can be realized is symbolized by the straight arrow and a Roman numeral I. The flow path through the primary heat source 3 / 2-way valve 21. G that can be realized in the second switching position of the primary heat source 3 / 2-way valve 21. G is symbolized by the curved arrow and a Roman numeral II.

[0097] According to the first embodiment of the central heating system 1 of Fig.1 a, a branch flow circuit inflow line LSK, ZU of the branch flow circuit KAB via the first 3-way connector 26.1 and via a second 3-way connector 26.2 arranged in the primary heat source discharge line LPQ, ab and / or interposed therein with the primary heat source discharge line Lpo, a b fluidically connected and / or to the primary heat source discharge line L PQ , ab connected. A branch flow circuit outlet line LSK, from the branch flow circuit KAB is connected to the first 3 / 2-way valve 21.1 and via a third 3-way connector 26.3 to the primary heat source inlet line LPQ, ZU fluidically connected and / or to the primary heat source inflow line LP Q , ZU connected.

[0098] According to the second embodiment of the central heating system 1 from Fig.1 b, a branch flow circuit inflow line LSK, ZU of the branch flow circuit KAB via the first 3 / 2-way valve 21.1 and via a primary heat source discharge line LPQ, a b arranged and / or interposed second 3-way connector 26.2 with the primary heat source discharge line LPQ, a b fluidically connected and / or to the primary heat source discharge line LPQ, ab connected. A branch flow circuit outlet line LSK, from the branch flow circuit KAB is connected to the first 3-way connector 26.1 and via a third 3-way connector 26.3 to the primary heat source inlet line LPQ, ZU fluidically connected and / or to the primary heat source inflow line L PQ , ZU connected.

[0099] The mentioned connections of the branch flow circuit inflow line LSK, ZUand the branch flow circuit drain line LSK, ab are particularly easy to implement or can be implemented in a simple manner because the primary heat source 2 has a primary heat source housing 2.G and the domestic hot water storage tank 5 has a domestic hot water storage tank housing 5.G arranged at a distance from the primary heat source housing 2.G. The second and third 3-way connecting pieces 26.2, 26.3 are then arranged between the primary heat source housing 2.G and the domestic hot water storage tank housing 5.G (cf. Fig. 1a and 1b). In particular, a non-return valve (not further designated) is also arranged in the primary source drain line L between the second 3-way connecting piece 26.2 and the primary heat source 2. PQ , a b arranged.

[0100] According to the third and fourth exemplary embodiments of the central heating system 1 shown in Figs. 2a and 2b, a water-to-water heat exchanger 27, in particular a plate heat exchanger, is provided, particularly embodied as a separate component. The branch flow circuit inflow line LSK, ZU of the branch flow circuit KAB is fluidly connected to and / or connected to a first side 27.1 of the water-to-water heat exchanger 27, so that the heat transfer fluid 6 can be supplied to the first side 27.1 through the branch flow circuit inflow line LSK, ZU. The branch flow circuit drain line LSK, ab of the branch flow circuit KAB is fluidically connected to the first side 27.1 and / or connected here, so that the heat transfer fluid 6 can be discharged from the first side 27.1 through the branch flow circuit drain line LSK, ab.A domestic water outlet line LBW, ab is fluidically connected and / or connected accordingly on the one hand to the domestic water storage tank 5 and on the other hand to a second side 27.2 of the water-water heat exchanger 27, so that the domestic water 11 can be supplied from the domestic water storage tank 5 to the second side 27.2 via the domestic water outlet line LBW, ab with the aid of a domestic water pump 10. A domestic water inlet line LBW, ab. ZU is fluidically connected and / or connected accordingly on the one hand to the domestic water storage tank 5 and on the other hand to the second side 27.2, so that the domestic water 11 is supplied through the domestic water inflow line LBW, ZUThe hot water can be fed to the domestic water storage tank 5 from the second side 27.2. A hot water pipe 17a is then fluidically connected to the domestic water outlet pipe LBW, ab and / or to the domestic water outlet pipe LBW, ab. A cold water pipe 17b is connected to the domestic water inlet pipe LBW, ZU fluidically connected and / or to the domestic water inflow line LBW, ZU connected. Heated domestic water 11, e.g., for a shower, can be drawn from the domestic water storage tank 5 via the hot water line 17a. Fresh, "cold" domestic water 11 can be supplied to the domestic water storage tank 5 via the cold water line 17b, particularly during or after domestic water 11, e.g., for a shower, has been drawn from the domestic water storage tank 5, in order to refill the domestic water storage tank 5 via the cold water line 17b.

[0101] The domestic water 11 can be heated via the water-to-water heat exchanger 27, in particular with the help of the heat pump 3. The water-to-water heat exchanger 27 is used in particular when a "direct" connection of the heat pump 3 to the heating line LHZ of the domestic water storage tank 5 would not be possible or would only involve excessive effort. This is particularly the case when the primary heat source 2 and the domestic water storage tank 5 have a common integral housing 28, as shown in Fig. 2a and Fig. 2b. In this case, the heating line LHZ, the primary heat source drain line Lpo, a b and the primary heat source inflow line LPQ, ZU, in particular each completely, are arranged within the integral housing 28 and are therefore not readily accessible.

[0102] The heating pump 8 is assigned to the water-air heat exchanger 4, the circulation pump 9 to the heat pump 3, and the heat source pump 9b to the primary heat source 2, namely, they are fluidically arranged in a section of the piping system 7 assigned to the respective unit 2, 3, 4 or in a partial piping section comprising the respective unit 2, 3, 4. During operation, there is no splitting or combining of the flow of the heat transfer fluid 6 between the respective pump 8, 9, 9b and the respective unit 2, 3, 4, and no valve is fluidically arranged between the respective pump 8, 9, 9b and the respective unit 2, 3, 4.

[0103] In the following, the respective branch flow circuits KAB and the first and second heating circuits already mentioned at the beginning are described in more detail:

[0104] A branch flow circuit KAB according to the embodiment shown in Fig. 1a is designed such that a flow of the heat transfer fluid 6 from the heat pump 3, via the circulation pump 9, via the first 3-way connecting piece 26.1, via the branch flow circuit inflow line LSK. ZU, via the second 3-way connecting piece 26.2, via the domestic hot water tank 5 or via the heating line LHZ, via the third 3-way connecting piece 26.3, via the branch flow circuit outflow line LsK, at>, via the first 3 / 2-way valve 21.1 in its first switching position, as well as via the 4 / 2-way valve 20 and back to the heat pump 3 can be realized. With the help of the branch flow circuit KAB according to Fig. 1 a, a flow of the heat transfer fluid 6 is also possible from the heat pump 3, via the circulation pump 9, via the first 3-way connector 26.1, via the branch flow circuit inlet line LSK. ZU, via the second 3-way connector 26.2, via the domestic hot water tank 5 orvia the heating line LHZ, via the third 3-way connecting piece 26.3, via the branch flow circuit drain line LsK, at>, via the first 3 / 2-way valve 21.1 in its first switching position, via the 4 / 2-way valve 20, via the water-air heat exchanger 4 and back to the heat pump 3.

[0105] A branch flow circuit KAB according to the embodiment shown in Fig. 1 b is designed such that a flow of the heat transfer fluid 6 from the heat pump 3, via the circulation pump 9, via the first 3 / 2-way valve 21.1 in its first switching position, via the branch flow circuit inflow line LSK. ZU, via the second 3-way connecting piece 26.2, via the domestic hot water tank 5 or via the heating line LHZ, via the third 3-way connecting piece 26.3, via the branch flow circuit outflow line LsK. ab, via the first 3-way connecting piece 26.1, as well as via the 4 / 2-way valve 20 and back to the heat pump 3 can be realized. With the help of the branch flow circuit KAB according to Fig.1 b, a flow of the heat transfer fluid 6 from the heat pump 3, via the circulation pump 9, via the first 3 / 2-way valve 21.1 in its first switching position, via the branch flow circuit inflow line LSK, ZU, via the second 3-way connecting piece 26 is also possible.2, via the domestic hot water tank 5 or via the heating line LHZ, via the third 3-way connector 26.3, via the branch flow circuit drain line LsK., via the first 3-way connector 26.1, via the 4 / 2-way valve 20, via the water-air heat exchanger 4 and back to the heat pump 3.

[0106] A further branch flow circuit KAB according to the embodiment shown in Fig.2a is designed such that a flow of the heat transfer fluid 6 from the heat pump 3, via the circulation pump 9, via the first 3-way connecting piece 26.1, via the branch flow circuit inflow line LSK, ZU, via the first side 27.1 of the water-water heat exchanger 27, via the branch flow circuit outflow line LSK, ab, via the first 3 / 2-way valve 21.1 in its first switching position, via the 4 / 2-way valve 20 and back to the heat pump 3 can be realized. With the help of the branch flow circuit KAB according to Fig.2a, a flow of the heat transfer fluid 6 is also possible from the heat pump 3, via the circulation pump 9, via the first 3-way connecting piece 26.1, via the branch flow circuit inflow line LSK, ZU, via the first side 27.1 of the water-water heat exchanger 27, via the branch flow circuit outflow line LSK, ab, via the first 3 / 2-way valve 21.1 in its first switching position, via the 4 / 2-way valve 20, via the water-air heat exchanger 4 and back to the heat pump 3.

[0107] A further branch flow circuit KAB according to the embodiment shown in Fig.2b is designed such that a flow of the heat transfer fluid 6 from the heat pump 3, via the circulation pump 9, via the first 3 / 2-way valve 21.1 in its first switching position, via the branch flow circuit inflow line LSK, to, via the first side 27.1 of the water-water heat exchanger 27, via the branch flow circuit outflow line LSK, from, via the first 3-way connecting piece 26.1, via the 4 / 2-way valve 20 and back to the heat pump 3 can be realized. With the help of the branch flow circuit KAB according to Fig.2b, a flow of the heat transfer fluid 6 from the heat pump 3, via the circulation pump 9, via the first 3 / 2-way valve 21.1 in its first switching position, via the branch flow circuit inflow line LSK, ZU, via the first side 27 is also possible.1 of the water-water heat exchanger 27, via the branch flow circuit drain line LSK, via the first 3-way connecting piece 26.1, via the 4 / 2-way valve 20, via the water-air heat exchanger 4 and back to the heat pump 3.

[0108] By means of the respective branch flow circuit KAB according to Figs. 1a and 1b, the domestic water 11 can be heated "directly," in particular with the aid of the heating line. By means of the respective branch flow circuit KAB according to Figs. 2a and 2b, the domestic water 11 can be heated "indirectly," in particular, with the aid of the water-to-water heat exchanger 27. However, during operation, either the domestic water 11 or the water-to-air heat exchanger 4 is preferably heated by means of the central heating system 1. Only the heating of the water-air heat exchanger 4 is made possible by means of the formation of a first heating circuit, wherein in the first heating circuit a flow of the heat transfer fluid 6 from the heat pump 3, via the circulation pump 9, via the first 3-way connecting piece 26.1 according to Fig.1a or 2a or via the first 3 / 2-way valve 21.1 according to Fig.1b or 2b in its second switching position, in particular via the primary heat source 3 / 2-way valve 21.G in a second valve position, in particular via the heat source pump 9b, via the primary heat source 2, via the first 3 / 2-way valve 21.1 according to Fig. 1a or 2a in its second switching position or via the first 3-way connecting piece according to Fig. 1b or 2b, via the 4 / 2-way valve 20, via the water-air heat exchanger 4 and back to the heat pump 3. The heat transfer fluid 6 preheated by the heat pump 3 can thus be completely supplied to the primary heat source 2. The heat transfer fluid 6 can be heated by the heat pump 3 and the primary heat source 2. However, the heat transfer fluid 6 can also flow through the primary heat source 2 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.

[0109] In a further, second heating circuit, a flow of the heat transfer fluid 6 can be realized from the primary heat source 2, via the domestic hot water tank 5 or via the heating line LHZ, in particular via the primary heat source 3 / 2-way valve 21.G, via the heat source pump 9b, and back to the primary heat source 2. The heat source pump 9b is necessary to form the second heating circuit. The first heating circuit and the branch flow circuits KAB can also be realized solely using the circulation pump 9.

[0110] The respective branch flow circuit KAB and the second heating circuit can also be implemented at least partially simultaneously, in which case the domestic water 11 can be heated both by means of the heat pump 3 and by means of the primary heat source 2.

[0111] According to Fig.1 a and Fig.1 b, the respective branch flow circuit KAB and the second heating circuit run partially parallel with a division of the flow of the heat transfer fluid 6 in the third 3-way connecting piece 26.3 and a merging of the flow of the heat transfer fluid 6 in the second 3-way connecting piece 26.2. According to Fig.2a and Fig.2b, the respective branch flow circuit KAB and the second heating circuit, or the respective flow paths realized thereby, are in particular completely separated from one another.

[0112] According to Fig.1a and Fig.1b, as already explained above, theoretically further flow paths are conceivable, wherein a flow of the heat transfer fluid 6 from the heat pump 3, via the circulation pump 9, via the first 3-way connecting piece 26.1 according to Fig.1a or via the first 3 / 2-way valve 21.1 in its second switching position according to Fig.1b, in particular via the primary heat source 3 / 2-way valve 21.G, in particular via the heat source pump 9b, via the primary heat source 2, via the second 3-way connecting piece 26.2, via the domestic hot water storage tank 5 or via the heating line LHZ, via the third 3-way connecting piece 26.3, via the one branch flow circuit discharge line LsK.ab, via the first 3 / 2-way valve 21.1 in its first switching position according to Fig.1a or the first 3-way connecting piece 26.1 according to Fig.1b, via the 4 / 2-way valve 20 and back to the heat pump 3.It is also conceivable for the heat transfer fluid 6 to flow from the heat pump 3, via the circulation pump 9, via the first 3-way connecting piece 26.1 according to Fig.1a or via the first 3 / 2-way valve 21.1 in its second switching position according to Fig.1b, in particular via the primary heat source 3 / 2-way valve 21.G, in particular via the heat source pump 9b, via the primary heat source 2, via the second 3-way connecting piece 26.2, via the domestic hot water storage tank 5 or via the heating line LHZ, via the third 3-way connecting piece 26.3, via the one branch flow circuit drain line LSK, at>, via the first 3 / 2-way valve 21.1 in its first switching position according to Fig.1a or the first 3-way connecting piece 26.1 according to Fig.1b, via the 4 / 2-way valve 20, via the water-air heat exchanger 4 and back to the heat pump 3. The previously described flow paths depend in particular on the switching position of the 4 / 2-way valve 20 orthe second and third 3 / 2-way valves 21.2 and 21.3, which functionally form the 4 / 2-way valve.

[0113] To form specific branch flow circuits KAB or specific flow paths, however, targeted control of the primary heat source 3 / 2-way valve 21.G is necessary, whereas specific branch flow circuits KAB or specific flow paths can advantageously be implemented independently of the switching position of the primary heat source 3 / 2-way valve 21.G. The latter is particularly advantageous if the control of the primary heat source 3 / 2-way valve 21.G was developed for a central heating system 1 without the heat pump 3 and the heat pump 3 was only retrofitted later. As already described above, the heat transfer fluid 6 preheated by the heat pump 3 can then be supplied in particular in its entirety to the primary heat source 2. The heat transfer fluid 6 can then be heated by means of the heat pump 3 and the primary heat source 2.Here, too, the heat transfer fluid 6 can only flow through the primary heat source 2 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. With particular reference to Figs. 1a, 1b, 2a, and 2b, the following should be noted regarding the positioning and / or arrangement of the check valves provided and / or arranged here in the piping system 7 for implementing the previously described flow paths and / or flow circuits:

[0114] As shown in Figs. 1a, 1b, 2a, and 2b, all embodiments described in these figures comprise at least one first check valve 29, which is arranged in the branch flow circuit inlet line LSK, ZU. Additionally, in the embodiments shown in Figs. 1a and 1b, a second check valve 30 is arranged at the corresponding position shown in Figs. 1a and 1b in the primary heat source outlet line L PQ , a b arranged, in particular fluidically upstream of the second 3-way connecting piece 26.2 and fluidically downstream of the branch of the heat exchanger inlet line LWT, ZU from the primary source discharge line L PQ , ab2a and 2b, a second check valve 31 is also arranged in the service water discharge line LBW, ab, in particular in terms of flow upstream of the service water pump 10. The respective first and second check valves 29, 30 or 29 and 31 prevent a corresponding backflow of the heat transfer fluid 6 or the service water 11. The designation “first” or “second” check valve is not restrictive here, but this designation / numbering of the check valves merely serves to designate them in more detail, and this should also be noted.

[0115] A central heating control and / or regulating device 12 is connected to the primary heat source 2 for its control and / or regulation. A temperature sensor 13.1 is arranged in a - vertically viewed - lower area of ​​the domestic hot water tank 5 or adjacent to this - vertically viewed - lower area of ​​the domestic hot water tank 5 for determining 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 transmission. 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.

[0116] 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 with the domestic water 11. In the preferred embodiment, however, the temperature sensor 13.1 - as can be seen in Fig. 3a and Fig. 3b - is arranged in or on a part of a domestic water inflow line LBW formed between an inflow valve 15 and an inflow connection 16 of the domestic water tank 5, in particular by means of a T-piece 18. Here, 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 LBW, ZU according to Fig.3a and Fig.3b in such a way that a part of the domestic water inflow line LBW, ZU is connected to a branch of the T-piece 18, so that the temperature sensor 13.1 is arranged at one of the two parallel connections of the T-piece 18 and closes this connection by means of a cap. The temperature sensor 13.1 preferably penetrates the T-piece 18 completely and, according to Fig. 3a and Fig. 5b, despite being arranged on the T-piece 18, is arranged with its measuring range within the domestic hot water storage tank 5. It would also be conceivable, however, for the measuring range of the temperature sensor 13.1 to be arranged within the domestic hot water supply line LBW, ZU, in particular within the T-piece 18.

[0117] On the other hand, it would also be quite conceivable that the temperature sensor 13.1 is arranged on the outside of the wall of the domestic hot water storage tank 5 or on the outside of the domestic hot water inlet pipe LBW, in which case the actual domestic hot water temperature T BI by means of the heat pump control and / or regulating device 14, preferably a temperature gradient occurring across the wall of the domestic hot water storage tank 5 or across a wall of the domestic hot water inflow line LBW is taken into account.

[0118] The arrangement of the temperature sensor 13.1 symbolized in Fig.1a, Fig.1b, Fig.2a and Fig.2b basically includes all variants described above.

[0119] According to Fig. 1a and Fig. 1b, the domestic water inflow line LBW, ZU and the cold water line 17b are implemented with one and the same component, thus there is no difference between the domestic water inflow line LBW, ZU and the cold water line 17b. Likewise, according to Fig. 1a and Fig. 1b, the domestic water outflow line LBW, ab and the hot water line 17a are implemented with one and the same component, thus there is no difference between the domestic water outflow line LBW, ab and the hot water line 17a.

[0120] According to Fig. 2a and Fig. 2b, the cold water line 17b is connected to the domestic water inlet line LBW, in particular by means of a 3-way connector. Furthermore, the hot water line 17a is connected to the domestic water outlet line LBW, ZU connected, in particular by means of a 3-way connector.

[0121] Fluidically adjacent to the inlet valve 15, a check valve 15.r is integrated and / or arranged in the cold water line 17b or interposed therein in order to prevent a backflow of the domestic water 11 from the domestic water storage tank 5 into the cold water line 17b even when the inlet valve 15 is open.

[0122] The domestic hot water storage tank 5 according to Fig. 3a can be used in particular in the first and second exemplary embodiments of the central heating system 1 shown in Fig. 1a and Fig. 1b. The domestic hot water storage tank 5 according to Fig. 3b is intended for use in the third and fourth exemplary embodiments of the central heating system 1 shown in Fig. 2a and Fig. 2b. Here, domestic hot water 11 can be supplied to the T-piece 18 not only from the inlet valve 15, but also from the second side 27.2 of the water-water heat exchanger 27, in particular via a 3-way connector arranged between the T-piece 18 and the inlet valve 15 or interposed therein.

[0123] The temperature sensor 13.1 is designed as a first temperature sensor 13.1 for determining a first actual domestic water temperature TBI. A second temperature sensor 13.2 is arranged in a—vertically viewed—middle or upper region of the domestic water storage tank 5 for measuring a second, preferably average actual domestic water temperature TB2. The second temperature sensor 13.2 is connected to the central heating control and / or regulating device 12 for control, signal, and / or data transmission. 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.

[0124] The two temperature sensors 13.1 and 13.2 are referred to as the first and second temperature sensors for the sake of clarity. The designation "first" and "second" therefore does not represent a relationship between them and is not to be considered restrictive. Another unambiguous designation for the two temperature sensors would also be conceivable.

[0125] 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 would be located inside the domestic hot water tank 5 with direct contact with the domestic hot water 11. In contrast, the second temperature sensor 13.2 could also be arranged externally on the wall of the domestic hot water tank 5.

[0126] 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, in particular, calculated by the heat pump control and / or regulating device 14 with the aid of the first temperature sensor 13.1 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 a second limit temperature T B2 G is below.

[0127] In principle, the control and / or regulation of the heat pump 3 and the primary heat source 2 takes place independently of one another. This means, in particular, that no parameters and / or measured values ​​for controlling the primary heat source 2, such as a fuel supply level, 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, while the control of the heat pump takes 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 to each other as well as by the specific arrangement of the two associated temperature sensors 13.1, 13.2 to each other. The first temperature sensor 13.1 - viewed vertically - is arranged in particular in the lower half and the second temperature sensor 13.2 - viewed vertically - is arranged in the upper half of the domestic hot water tank 5 relative to the total vertical height of the domestic hot water tank 5, or the respective actual temperatures of the domestic hot water 11 are determined there.

[0128] For example, the first limit temperature T B I G less than the second limit temperature T B2 G- On the other hand, the second limit temperature T B2G is smaller than the first limit temperature TBIG. In this case, the second limit temperature T B2 G can then be set to 3°C to 7°C, especially 5°C lower than the first limit temperature TBIG-

[0129] The power of the heat pump 3 can be continuously adjusted, 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.

[0130] The maximum output of primary heat source 2 is, for example, 17 kW, whereby the output of primary heat source 2 is preferably 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 via the central heating system 1 with simultaneous operation of primary heat source 2 and heat pump 3, which is sufficient to supply heat to typical residential buildings.

[0131] The line system 7 has at least one 4 / 2-way valve 20 which is arranged and / or functionally effective in terms of flow between the first 3 / 2-way valve 21.1 according to Fig.1 a or Fig.2a or the first 3-way connecting piece 26.1 according to Fig.1 b or Fig.2b on the one hand and the water-air heat exchanger 4 and the heat pump 3 on the other hand, with the aid of which 4 / 2-way valve the heat transfer fluid 6 can be conducted and / or guided to the water-air heat exchanger 4 or past the water-air heat exchanger 4, in particular directly to the heat pump 3. The 4 / 2-way valve 20 is shown in Fig.1a, Fig.1b, Fig.2a and Fig.2b initially as a single 4 / 2-way 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 correspondingly present, in particular in order to then realize the functionally effective 4 / 2-way valve 20 accordingly.

[0132] The line system 7 therefore has in particular (alternatively to a single, in particular complexly designed 4 / 2-way valve 20) in the preferred embodiment two 3 / 2-way valves 21.2, 21.3 each with three connections and two switching positions, namely a second, in particular in the heat exchanger inflow line LWT, ZU arranged and / or interposed, 3 / 2-way valve 21.2 and a third, in particular in the heat pump inlet line L W p, zuarranged and / or interposed, a 3 / 2-way valve 21.3. The second 3 / 2-way valve 21.2 is fluidly connected to the first 3 / 2-way valve 21.1 according to Fig.1a or Fig.2a or to the first 3-way connector 26.1 according to Fig.1b or Fig.2b, the water-air heat exchanger 4, and the third 3 / 2-way valve 21.3. The third 3 / 2-way valve 21.3 is fluidly connected to the water-air heat exchanger 4, the second 3 / 2-way valve 21.2, and the heat pump 3. By means of the second 3 / 2-way valve 21.2, a flow of the heat transfer fluid 6 is optionally enabled from the first 3 / 2-way valve 21.1 according to Fig.1a or Fig.2a or with the first 3-way connecting piece 26.1 according to Fig.1b or Fig.2b to the water-air heat exchanger 4 or to the third 3 / 2-way valve 21.3. By means of the third 3 / 2-way valve 21.3, a flow of the heat transfer fluid 6 is optionally enabled from the water-air heat exchanger 4 or from the second 3 / 2-way valve 21.2 to heat pump 3.

[0133] The 4 / 2-way valve 20 or the 3 / 2-way valves 21.2 and 21.3 are connected in particular to the heat pump control and / or regulating device 14 in terms of control technology, or the corresponding switching positions of the 4 / 2-way valve 20, in particular the switching positions of the 3 / 2-way valves 21.2 and 21.3, can be set or switched accordingly with the aid of the heat pump control and / or regulating device 14.

[0134] These described flow paths, which can be implemented using the two 3 / 2-way valves 21.2, 21.3, could also be implemented using a single 4 / 2-way valve 20 (shown as a dashed line in Fig. 1a, 1b, 2a, 2b), whereby this one 4 / 2-way valve 20 has four connections and two switching positions. In the first switching position of the 4 / 2-way valve 20, a flow of the heat transfer fluid 6 via the water-air heat exchanger 4 to the heat pump 3 is enabled, whereby in a second switching position of the 4 / 2-way valve 20, a flow of the heat transfer fluid 6 past the water-air heat exchanger 4, in particular directly to the heat pump 3, is enabled. The switching positions of the previously described 4 / 2-way valve 20 are then also controlled or switched accordingly, in particular with the aid of the heat pump control and / or regulating device 14.Such a 4 / 2-way valve 20 could also be functionally effective using only a 3 / 2-way valve and a 3-way connector fluidically connected to this 3 / 2-way valve. It would therefore also be conceivable to replace one of the two 3 / 2-way valves 21.2 or 21.3 with a 3-way connector to form the 4 / 2-way valve 20. 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, to at least some sections of the heat pump drain line L Wp, from at least some sections of the 4 / 2-way valve 20, in particular the second 3 / 2-way valve 21.2 and the third 3 / 2-way valve 21.3, at least two, in particular all, elements and / or components and respective associated connections are arranged and / or formed on a first hydraulic module 22.1 forming a common structural unit. In this case, the respective aforementioned lines can also be formed in sections in this first hydraulic module 22.1.

[0135] From the group of the following elements and / or components, namely the heat exchanger inflow line LWT, ZU at least in sections, the branch flow circuit inflow line LSK, ZU at least in sections, the branch flow circuit outflow line LSK, ab at least in sections, the heat pump outflow line L Wp, at least in sections, of the first 3-way connector 26.1 and the first 3 / 2-way valve 21.1, at least two, in particular all, elements and / or components and respective associated connections are arranged and / or formed on a second hydraulic module 22.2 forming a common structural unit. Here, too, the respective aforementioned lines can be formed or become formed in sections in this second hydraulic module 22.2.

[0136] From the group of the following elements and / or components, namely the branch flow circuit inflow line LSK, to at least some sections, the branch flow circuit outflow line LSK, from at least some sections, the water-water heat exchanger 27, the domestic water inflow line L Bw, to at least some sections, the domestic water discharge line LBW, from at least some sections, and the domestic water pump 10, at least two, in particular all, elements and / or components and the respective associated connections are arranged and / or formed on a third hydraulic module 22.3 forming a common structural unit. Here, too, the respective aforementioned lines can now be formed in sections in this third hydraulic module 22.3.

[0137] The hydraulic modules 22.1, 22.2, 22.3 are symbolized by dash-dotted lines according to Fig. 1a, Fig. 1b, Fig. 2a and 2b. In particular, the one 4 / 2-way valve 20 or the two 3 / 2-way valves 21.2, 21.3 are also part of the first hydraulic module 22.1. The circulation pump 9 can in particular also be arranged outside the first hydraulic module 22.1, e.g., within / as part of the heat pump 3. The hydraulic modules 22.1, 22.2, 22.3 can preferably be pre-assembled in a factory and / or by a heating engineer, so that the assembly effort on site in the end customer's building can be reduced and simple and cost-effective assembly is enabled.

[0138] The heat pump control and / or regulating device 14 is connected to the central heating control and / or regulating device 12 to supply power 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 heat pump 8 for control and / or regulation of the heating pump 8 and / or the heat pump control and / or regulating device 14 is connected to the circulation pump 9 for control and / or regulation of the circulation pump 9 and / or the heat pump control and / or regulating device 14 is connected to the domestic water pump 10 for control and / or regulation of the domestic water pump 10 and / or the heat pump control and / or regulating device 14 is connected to the first 3 / 2-way valve 21 for control and / or regulation of the first 3 / 2-way valve 21.1.1 and / or the heat pump control and / or regulating device 14 is connected in terms of control technology to the 4 / 2-way valve 20 for controlling and / or regulating the 4 / 2-way valve 20, in particular the second and third 3 / 2-way valves 21 .2 and 21 .3, 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. aconnected for control / signal / and / or data purposes. Furthermore, the heat pump control and / or regulating device 14 is operatively connected for control / signal / and / or data purposes to the first temperature sensor 13.1. The central heating control and / or regulating device 12 is connected for control purposes to the heat source pump 9b for control and / or regulation, and / or the central heating control and / or regulating device 12 is connected for control purposes to the primary heat source 3 / 2-way valve 21.G for control and / or regulation. This applies to the first, second, third and fourth exemplary embodiments of the central heating system 1 according to Fig. 1a, Fig. 1b, Fig. 2a and Fig. 2b. These connections are symbolized by dashed lines, which are shown as broken lines.

[0139] The operation and / or control and / or regulation of the central heating system 1, in particular of the central heating system 1 according to Fig. 1a, Fig. 1b, Fig. 2a or Fig. 2b, will now be described in more detail: The 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, can be conveyed and / or is conveyed accordingly by means of the at least one pump 8, 9, 9b through part of a line system 7 and through the water-air heat exchanger 4 in order to heat the environment adjacent to the water-air heat exchanger 4 by means of the water-air heat exchanger 4. The heat transfer fluid 6 is optionally conveyed by means of at least one pump 8, 9, 9b through a further part of the line 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 can be selectively conveyed by means of the at least one pump 8, 9, 9b through a further part of the line system 7 and through the primary heat source 2 and / or is conveyed accordingly in order to heat the heat transfer fluid 6 by means of the primary heat source 2.

[0140] The first 3 / 2-way valve 21.1 is switched to a first switching position and thus, according to Fig.1 a or Fig.2a, a flow of the heat transfer fluid 6 from the branch flow circuit discharge line LSK, down to a region of the heat exchanger inflow line LWT, ZU that is fluidically facing the water-air heat exchanger 4 and / or the heat pump 3 is enabled in order to supply the heat transfer fluid 6 to the water-air heat exchanger 4 and / or the heat pump 3 from the primary heat source inflow line L Q , ZUor from the first side 27.1 of the water-water heat exchanger 27. Alternatively, the first 3 / 2-way valve 21.1 is switched to a second switching position and thus, according to Fig.1a, Fig.2a, a flow of the heat transfer fluid 6 is then enabled from a region of the heat exchanger inflow line LWT, to fluidically upstream of the first 3 / 2-way valve 21.1 to the region of the heat exchanger inflow line LWT, ZU fluidically facing the water-air heat exchanger 4 and / or the heat pump 3 in order to supply the heat transfer fluid 6 to the water-air heat exchanger 4 and / or the heat pump 3 from the primary heat source outflow line LPQ, and thus in particular to fluidically bypass the heating line LHZ and / or the water-water heat exchanger 27.

[0141] According to Fig. 1 b, Fig. 2b, when the first 3 / 2-way valve 21.1 is switched to a first switching position, a flow of the heat transfer fluid 6 from a region of the heat pump discharge line LWP, from fluidically upstream of the first 3 / 2-way valve 21.1 into the branch flow circuit inflow line LSK, ZU enables the heat transfer fluid 6 from the heat pump 3 to be supplied to the heating line LHZ or to the first side 27.1 of the water-water heat exchanger 27. Alternatively, the first 3 / 2-way valve 21.1 is switched to a second switching position and thus, according to Fig.1 b or Fig.2b, a flow of the heat transfer fluid 6 from the area of ​​the heat pump discharge line L Wp, from fluidically upstream of the first 3 / 2-way valve 21.1 to the primary heat source inflow line LPQ, ZU, enables the heat transfer fluid 6 to be supplied to the primary heat source 2 and, in particular, thus fluidically bypassing the heating line LHZ and / or the water-water heat exchanger 27. The bypassing of the heating line LHZ and the water-water heat exchanger 27 with the first 3 / 2-way valve 21.1 in the second switching position can be ensured according to the situation shown in Fig. 2b. According to Fig. 1b, at least partial flow through the heating line LHZ with the first 3 / 2-way valve 21.1 in the second switching position cannot be ruled out, but at least this flow through the heating line LHZ is then correspondingly small due to the flow resistance occurring here.

[0142] The central heating system 1 is therefore operated in particular by forming one of the four described branch flow circuits KAB or the described flow paths and / or one of the two described heating circuits.

[0143] With the aid of the temperature sensor 13.1, the first actual domestic hot water temperature TBI is measured, determined, and / or calculated in a—vertically viewed—lower area of ​​the domestic hot water storage tank 5, in particular by a heat pump control and / or regulating device 14. The heat pump 3 is controlled and / or regulated by a heat pump control and / or regulating device 14 depending on the determined first actual domestic hot water temperature TBI.

[0144] This leads to several advantages. Firstly, it allows for 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 independently of one another or control the entire central heating system 1 essentially independently of one another. The heat pump control and / or regulating device 14 is therefore not connected, in particular in terms of control technology, to the central heating control and / or regulating device 12. A system which, for example, initially only has a primary heat source 2 and the central heating control and / or regulating device 12 can therefore be easily and cost-effectively retrofitted with a heat pump 3 and the heat pump control and / or regulating device 14.1 determines the first actual domestic hot water temperature TBI in the - vertically viewed - lower area of ​​the domestic hot water storage tank 11, the heat pump 3 can be quickly controlled without a significant time delay and without extensive and complex control effort using the heat pump control and / or regulation device 14. This helps to avoid initially controlling the primary heat source 2, which in turn can save fuel.

[0145] The first actual domestic hot water temperature TBI is transmitted to the heat pump control and / or regulating device 14 and / or determined and / or calculated by the heat pump control and / or regulating device 14. The second, preferably average, actual domestic hot water temperature TB2 is measured, determined and / or calculated by the second temperature sensor 13.2 in a—vertically viewed—middle or upper region of the domestic hot water storage tank 5. The second actual domestic hot water temperature TB 2 is transmitted to the central heating control and / or regulation device 12 and / or determined and / or calculated by the central heating control and / or regulation device 12. The primary heat source 2 is controlled by the central heating control and / or regulation device 12 depending on the second actual domestic water temperature T B 2 controlled and / or regulated.

[0146] The heat pump 3 is operated and / or activated with the aid of the heat pump control and / or regulating device 14 to heat the heat transfer fluid 6 and the first 3 / 2-way valve 21.1 is switched into its first switching position with the aid of the heat pump control and / or regulating device 14 when the first actual domestic water temperature TBI measured, determined and / or calculated with the aid of the first temperature sensor 13.1 exceeds the first limit temperature T B IG falls below.

[0147] 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 regulation device 14, in particular additionally as a function of a first actual heat transfer fluid temperature Twi which forms at the outlet of the heat pump 3.

[0148] 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 during operation of the heat pump 3. In particular, the heat pump 3 is therefore 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,soii 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, son, 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, son again, in particular the corresponding desired first actual heat transfer fluid temperature Twi, son is then actually reached or realized as the actual heat transfer fluid temperature Twi at the outlet of the heat pump 3.

[0149] 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 and in particular the primary heat source 3 / 2-way valve 21.G is switched into a first switching position for connecting the heating line LHZ to the primary heat source 2 with the aid of the central heating control and / or regulating device 12 and / or the heat source pump 9b is operated and / or activated with the aid of the central heating control and / or regulating device 12 when the second actual domestic water temperature TB2 measured, determined and / or calculated with the aid of the second temperature sensor 13.2 exceeds the second limit temperature T B 2G, so that the second heating circuit is then realized.

[0150] The primary heat source 2 and / or the heat source pump 9b is further controlled and / or regulated by the central heating control and / or regulation device 12 as a function of a second actual heat transfer fluid temperature TW2 that develops within or in the area of ​​the primary heat source 2. In particular, the primary heat source 2 is additionally controlled as a function of a second target heat transfer fluid temperature T set for the primary heat source 2. W 2,son controlled and / or regulated. If the temperature of the heat transfer fluid 6 measured within the primary heat source 2, i.e., the actual heat transfer fluid temperature TW2, falls below the target heat transfer fluid temperature Tw2 set for the primary heat source 2, then the primary heat source 2 is operated accordingly to heat the heat transfer fluid 6 accordingly. This is also implemented accordingly using the central heating control and / or regulation device 12.

[0151] These sequences for operating and / or controlling and / or regulating the heat pump 3 of the central heating system 1 according to Fig.1a, Fig.1b, Fig.2a or Fig.2b are explained in more detail here using a schematic representation of a flow diagram according to Fig.4. First, it is continuously checked whether the first actual domestic hot water temperature TBI is below the first limit temperature TBIG. If this is the case, the method step VWPI is carried out, namely the corresponding operation / control and / or activation of the heat pump 3 and the switching of the first 3 / 2-way valve 21.1 to its first switching position and the operation and / or activation of the circulating pump 9. In the third and fourth embodiments from Fig.2a and Fig.2b, the domestic hot water pump 10 is then also operated / controlled and / or activated.The heat pump 3, the circulation pump 9, and in particular the domestic hot water pump 10 are then operated, in particular, until the first actual domestic hot water temperature TBI is again above the first limit temperature TBIG. In contrast, it is also conceivable that a first switch-off limit temperature TBIG' is provided, which is preferably 4°C to 6°C above the first limit temperature TBIG, and the heat pump 3, the circulation pump 9, and in particular the domestic hot water pump 10 are then operated, in particular, until the first actual domestic hot water temperature TBI is above the first switch-off limit temperature T. B IG'. If the first actual domestic hot water temperature TBI is the first limit temperature T B IG or the first switch-off limit temperature T B I G ', process step V WP2, namely a different operating mode and / or even the deactivation of the heat pump 3, the circulation pump 9 and especially the domestic hot water pump 10. The process then starts again by checking whether the first actual domestic hot water temperature T B I is below the first limit temperature TBIG. The process steps described above are carried out in particular when domestic water 11 is withdrawn from the domestic water storage tank 5, e.g., for a shower, and new, "colder" domestic water is then added to the domestic water.

[0152] 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 a, Fig. 1 b, Fig. 2a or Fig. 2b are illustrated in more detail here using a schematic representation of a flow chart according to Fig. 5. Here, first, a continuous check is carried out to determine whether the second actual domestic water temperature TB2 below the second limit temperature T B2 G' is located. If this is the case, the method step VPRI , namely the operation and / or activation of the primary heat source 2 and in particular the switching of the primary heat source 3 / 2-way valve 21.G into its first switching position to realize the second heating circuit and in particular the operation and / or activation of the heat source pump 9b, is carried out. It would also be conceivable to switch the primary heat source 3 / 2-way valve 21.G into its second switching position to realize in particular the third branch flow circuit K AB . The primary heat source 2 is then operated until the second actual domestic water temperature T B2 again above the second limit temperature T B2G It is also conceivable, however, that a second switch-off limit temperature TB2G' is provided, which is preferably 4°C to 6°C above the second limit temperature T B2G 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 hot water temperature T B 2 is the second limit temperature T B 2G or the second switch-off limit temperature TB2G', the process step VPR2 is carried out, namely a different operating mode and / or the deactivation of the primary heat source 2. The process then starts again with the check whether the second actual domestic hot water temperature T B2 is below the second limit temperature TB2G. The process steps described above are carried out in particular when domestic water is withdrawn from the domestic water storage tank, e.g., for a shower, and new, "colder" domestic water is then added back to the domestic water. The process steps described in Fig. 4 particularly occur before the process steps described in Fig. 5. Simply put, the correspondingly implemented control ensures that the heat pump 3 is activated or used preferentially before the primary heat source 2 for heating the domestic water 11.

[0153] But even in a "normal heating operation", namely when the first heating circuit of the central heating system is formed, i.e. when the domestic water 11 does not need to be heated and, for example, only the heat transfer fluid 6 needs to be heated to operate the water-air heat exchanger 4, the heat pump 3 in particular can and will always be used preferentially before 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.

[0154] The first and second limit temperatures TBIG, T B2G 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, in particular the primary heat source 3 / 2-way valve 21.G is switched to its first switching position, and in particular the heat source pump 9b is only operated and / or activated, when a heat demand of the domestic hot water storage tank 5 exceeds a heat quantity that can be provided by the heat pump 3 at maximum power of the heat pump 3. This is particularly the case when the second actual domestic hot water temperature TB2 falls below the second limit temperature T B2G drops, in particular although the heat pump 3 is operating at full capacity. The heat pump 3 and / or the circulation pump 9 are controlled and / or regulated by the heat pump control and / or regulation device 14, in particular additionally, as a function of a first actual heat transfer fluid temperature Twi, formed at the outlet of the heat pump 3 and / or as a function of a first target heat transfer fluid temperature Twi, son specified for the outlet of the heat pump 3. The previously mentioned method step V WPI (see also Fig. 4), namely, in particular, the operation and / or control of the heat pump 3 is then also carried out as a function of this first actual heat transfer fluid temperature Twi and this first target heat transfer fluid temperature Twi, in particular in order to then heat the domestic water 11 accordingly. Various 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, using digital programs or also using analog circuits.

[0155] The primary heat source 2 and in particular the heat source pump 9b are controlled by the central heating control and / or regulating device 12 as a function of a second actual heat transfer fluid temperature TW2, which develops within or in the area of ​​the primary heat source 2, and / or as a function of a second target heat transfer fluid temperature T, which is predetermined for the inner area of ​​the primary heat source 2. W 2, son controlled and / or regulated. The previously mentioned process step V PRi (see Fig.5), namely the operation and / or control, in particular the activation of the primary heat source 2 and in particular the operation and / or control, in particular the activation of the heat source pump 9b are 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 carried out.

[0156] Different types of controls and / or regulation can also be used for the heating pump 8, the circulation pump 9, the heat source pump 9b and / or the domestic hot water pump 10, which are or will be implemented, for example, using digital programs or analog circuits.

[0157] The second target heat transfer fluid temperature T W 2, son is below the first target heat transfer fluid temperature Twi, son such that 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 only when a heat requirement of the central heating system 1, in particular a heat requirement of the water-air heat exchanger 4 and / or the domestic hot water storage tank 5, exceeds a heat quantity that can be provided by means of the heat pump 3 at maximum output of the heat pump 3.

[0158] However, if the performance of the heat pump 3 is sufficient to cover the heat demand of the central heating system 1, in particular the heat demand of the water-air heat exchanger 4 and / or the domestic hot water storage tank 5, then the heat transfer fluid 6 becomes the primary heat source 2, in particular when implementing the first heating circuit with an actual heat transfer fluid temperature above the second target heat transfer fluid temperature T W 2, son reach, so that then also the second actual heat transfer fluid temperature Tw2 present in the primary heat source 2 is above the second target heat transfer fluid temperature T W 2, son, and the primary heat source 2 therefore does not need to be activated and operated with fuel combustion. These processes are particularly relevant when the first heating circuit is implemented, i.e., only the water-air heat exchanger 4 and, in particular, not the domestic water n is heated.

[0159] The values ​​of the target heat transfer fluid temperatures Twi, son, T W 2, are in particular also selected 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 the water-air heat exchanger 4 and / or the domestic water 11 taken from the domestic water storage tank 5.

[0160] 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 hot water storage tank 5 exceeds a heat quantity that can be provided by the heat pump 3 at maximum output is further ensured by the fact that the first actual domestic hot water temperature TBI - viewed vertically - is measured below the second actual domestic hot water temperature TB2, wherein the domestic hot water 11 can be supplied, in particular, as shown below in Fig. 3a and Fig. 5b, in the region of the measured first actual domestic hot water temperature TBI. If, in comparison to the already heated domestic hot water 11 present in the domestic hot water storage tank 5, fresh, cold domestic hot water 11 is supplied to the domestic hot water storage tank 5, the first actual domestic hot water temperature TBI will initially drop over time.The second actual domestic water temperature TB2 will only drop later, once the fresh, cold domestic water 11, or its temperature, has spread to the second temperature sensor 13.2. The first limit temperature TBIG is reached when cold domestic water 11 is supplied, depending on the appropriate selection of the limit temperatures TBIG and T. B 2G to each other, therefore, in particular, the corresponding first actual domestic water temperature TBI must always be undercut before the second limit temperature T B 2G by the second actual domestic water temperature T B 2, so that the heat pump 3 is always operated preferentially, especially 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 demand of the domestic hot water storage tank 5, the second actual domestic hot water temperature T B2 not below the second limit temperature T B2Gand primary heat source 2 does not need to be activated and therefore does not need to be operated with fuel combustion. The values ​​of the limit temperatures TBIG, T B2G 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 ensure a comfortable temperature of the domestic water 11 taken from the domestic water storage tank 5.

[0161] The first limit temperature T B I G is either below the second limit temperature T B2G as shown in Fig.6a or the first limit temperature T B I G is above the second limit temperature T B2G as shown in Fig.6b.

[0162] The heating pump 8 and / or the circulation pump 9 are, in particular depending on an outside temperature T measured by an outside temperature sensor 13. a a, controlled and / or regulated by means of the heat pump control and / or regulation device 14. The heat source pump 9b is, in particular, dependent on an outside temperature T measured by means of a further outside temperature sensor 13.b a , controlled and / or regulated by means of the central heating control and / or regulation device 12.

[0163] The heating pump 8 and / or the circulation pump 9 are, in particular, initially operated and / or activated synchronously with the heat pump 3. Synchronous control is made possible in particular by controlling and / or regulating both the heating pump 8 and / or the circulation pump 9 and the heat pump 3 by means of the heat pump control and / or regulating device 14.

[0164] Fig.6a and Fig.6b show in a very simplified schematic representation a respective dependence of the first target heat transfer fluid temperature Twi. soii, the first limit temperature T B I G, the second target heat transfer fluid temperature T W 2, son or the second limit temperature T B2G to the outside temperature T a , as they are stored, for example, in tabular form or as a formula in the heat pump control and / or regulation device 14 or in the central heating control and / or regulation device 12. Here, in Fig. 6a and Fig. 6b, the respective graphs are shown as examples and in a highly simplified schematic. The first and second limit temperatures T B IG, T B 2G are shown in Fig.6a and Fig.6b as horizontal lines parallel to the X-axis of the outside temperature T a The first and second limit temperatures TBIG, T B2 G are thus present in particular as constant values ​​in the heat pump control and / or regulation device 14 or in the central heating control and / or regulation device 12, so that the first and second limit temperatures TBIG, T B2G for simplicity independent of the outside temperature T a are.

[0165] 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, especially 8°C with T W 2, son < Twi, son- The second limit temperature T B2G is smaller than the second target heat transfer fluid temperature T W 2, son- In particular, effective heating of the domestic water 11 can be achieved by means of the primary heat source 2.

[0166] 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.

[0167] List of reference symbols

[0168] central heating system

[0169] Primary heat source .G Primary heat source housing

[0170] heat pump

[0171] Water-air heat exchanger

[0172] Domestic hot water storage tank .G Domestic hot water storage tank housing

[0173] Heat transfer fluid

[0174] piping system

[0175] heating pump

[0176] Circulation pump b Heat source pump 0 Domestic hot water pump 1 Domestic hot water 2 Central heating control and / or regulating device 3.1 First temperature sensor 3.2 Second temperature sensor 3. a Outside temperature sensor 3. b Outside temperature sensor 4 Heat pump control and / or regulating device 5 Inlet valve 5. r Check valve 6 Inlet connection 7a Hot water pipe 7b Cold water pipe 8 T-piece 9 Inverter 0 4 / 2-way valve 1.1 First 3 / 2-way valve 1.2 Second 3 / 2-way valve 1.3 Third 3 / 2-way valve 1. G Primary heat source 3 / 2-way valve 2.1 First hydraulic module 2.2 Second hydraulic module 2.3 Third hydraulic module

[0177] 26.1 first 3-way connector

[0178] 26.2 second 3-way connector

[0179] 26.3 third 3-way connector

[0180] 27 water-water heat exchangers

[0181] 27.1 First side of the water-water heat exchanger 27

[0182] 27.2 second side of the water-water heat exchanger 27

[0183] 28 integral housings

[0184] 29 Check valve

[0185] 30 Check valve

[0186] 31 Check valve

[0187] KAB branch flow circuit

[0188] TBI first actual domestic water temperature

[0189] TB2 second actual domestic water temperature

[0190] TBIG first limit temperature

[0191] TBI G ' first switch-off limit temperature

[0192] TB2G second limit temperature

[0193] TB2G' second switch-off limit temperature

[0194] T a Outside temperature

[0195] Twi first actual heat transfer fluid temperature

[0196] TW2 second actual heat transfer fluid temperature

[0197] Twi . soii first target heat transfer fluid temperature

[0198] TW2, second target heat transfer fluid temperature

[0199] LWT, ZU heat exchanger inflow line

[0200] LWP, to heat pump inlet line

[0201] LWP, from heat pump drain line

[0202] LHZ heating cable

[0203] LPQ, from primary heat source drain line

[0204] LPQ, ZU primary heat source inflow line

[0205] LSK, ZU branch flow circuit inflow line

[0206] LSK, from branch flow circuit drain line LBW, from service water drain line

[0207] LBW, ZU domestic water inflow line

[0208] VWPI Operating and / or activating the heat pump 3, switching the first 3 / 2-way valve 21 .1 to its first switching position and operating and / or activating the circulation pump 9

[0209] V W P2 Deactivation of heat pump 3 and circulation pump 9

[0210] VPRI Operating and / or activating the primary heat source 2

[0211] VPR2 Deactivation of primary heat source 2

Claims

Patent claims 1. Central heating system (1) with at least one primary heat source (2) operable with the aid of fuels, in particular a gas boiler or a heating boiler, with at least one electrically operable heat pump (3), with at least one water-air heat exchanger (4), preferably a heating element or a radiator for heating a building, and with at least one domestic water storage tank (5), in particular a boiler, for the temporary storage of domestic water (11), wherein a heat transfer fluid (6), in particular water, can be heated by means of the primary heat source (2) and / or by means of the heat pump (3), wherein the heat transfer fluid (6) can be conveyed by means of a piping system (7) and by means of at least one pump (8, 9, 9b), in particular a heating pump (8), a circulating pump (9) and / or a heat source pump (9b) for heating by the heat pump (3) and / or, in particular, for heating by the primary heat source (2),wherein a heat exchanger inflow line (LWT, ZU) of the line system (7) is fluidically connected and / or correspondingly connected on the one hand to the primary heat source (2) and on the other hand to the water-air heat exchanger (4), so that the heat transfer fluid (6) can be fed to the water-air heat exchanger (4) through the heat exchanger inflow line (LWT, ZU), wherein a heat pump inflow line (L, W p, zu ) of the pipe system (7) is fluidically connected and / or connected accordingly to the water-air heat exchanger (4) on the one hand and to the heat pump (3) on the other hand, so that the heat transfer fluid (6) can be fed to the heat pump (3) through the heat pump inlet pipe (LWP, to), wherein a heat pump outlet pipe (L Wp, 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) and / or is connected accordingly, so that the heat transfer fluid (6) can be fed through the heat pump outlet line (LWP, ab) to the primary heat source (2), characterized in that a - first - 3 / 2-way valve (21.1) is arranged in the heat exchanger inflow line (LWT, ZU) and / or is interposed therein, wherein a - first - 3-way connecting piece (26.1) is arranged in the heat pump outlet line (LWP, ab) and / or is interposed therein, so that by means of a branch of the 3 / 2-way valve (21.1) and a branch of the 3-way connecting piece (26.1 ) a branch flow circuit (KAB) of the line system (7) is formed, wherein the heat transfer fluid (6) can be conveyed through the branch flow circuit (KAB) by means of the at least one pump (8, 9, 9b) and the service water (11) can be heated with the aid of the heat transfer fluid (6) flowing through the branch flow circuit (KAB).

2. Central heating system (1) with at least one primary heat source (2) operable with the aid of fuels, in particular a gas boiler or a heating boiler, with at least one electrically operable heat pump (3), with at least one water-air heat exchanger (4), preferably a heating element or a radiator for heating a building, and with at least one domestic water storage tank (5), in particular a boiler, for the temporary storage of domestic water (11), wherein a heat transfer fluid (6), in particular water, can be heated by means of the primary heat source (2) and / or by means of the heat pump (3), wherein the heat transfer fluid (6) can be conveyed by means of a piping system (7) and by means of at least one pump (8, 9, 9b), in particular a heating pump (8), a circulating pump (9) and / or a heat source pump (9b) for heating by the heat pump (3) and / or, in particular, for heating by the primary heat source (2),wherein a heat exchanger inflow line (LWT, ZU) of the line system (7) is fluidically connected and / or connected accordingly on the one hand to the primary heat source (2) and on the other hand to the water-air heat exchanger (4), so that the heat transfer fluid (6) can be fed to the water-air heat exchanger (4) through the heat exchanger inflow line (LWT, ZU), wherein a heat pump inflow line (L, W p, zu ) of the pipe system (7) is fluidically connected and / or connected accordingly to the water-air heat exchanger (4) on the one hand and to the heat pump (3) on the other hand, so that the heat transfer fluid (6) can be fed to the heat pump (3) through the heat pump inlet pipe (LWP, to), wherein a heat pump outlet pipe (L Wp, 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) and / or is connected accordingly, so that the heat transfer fluid (6) can be fed through the heat pump outlet line (LWP, ab) to the primary heat source (2), characterized in that a - first - 3-way connecting piece (26.1) is arranged in the heat exchanger inflow line (LWT, zu) and / or is interposed here, wherein a - first - 3 / 2-way valve (21.1) is arranged in the heat pump outlet line (LWP, ab) and / or is interposed here, so that by means of a branch of the 3-way connecting piece (26.1) and a branch of the 3 / 2-way valve (21.1 ) a branch flow circuit (KAB) of the line system (7) is formed, wherein the heat transfer fluid (6) can be conveyed through the branch flow circuit (KAB) by means of the at least one pump (8, 9, 9b) and the service water (11 ) can be heated with the aid of the heat transfer fluid (6) flowing through the branch flow circuit (KAB).

3. Central heating system (1) according to claim 1 or 2, characterized in that inside the domestic water storage tank (5), inside a wall of the domestic water storage tank (5) and / or outside on the wall of the domestic water storage tank (5) a heating line (LHZ) is arranged and / or designed such that when the heat transfer fluid (6) flows through the heating line (LHZ), the service water (11) then present in the service water storage tank (5) can be heated by means of the heat transfer fluid (6), wherein a primary heat source discharge line (L PQ, ab) of the pipe system (7) is fluidically connected and / or connected accordingly to the primary heat source (2) on the one hand and to the heating pipe (LHZ) on the other hand, so that the heat transfer fluid (6) is discharged through the primary heat source discharge pipe (L PQ , ab) of the heating line (LHZ), wherein a primary heat source inflow line (L PQ , zu ) of the pipe system (7) is fluidically connected and / or connected accordingly to the heating pipe (LHZ) on the one hand and to the primary heat source (2) on the other hand, so that the heat transfer fluid (6) is supplied through the primary heat source inflow pipe (L PQ , zu ) of the primary heat source (2), wherein the heat exchanger inflow line (LWT, ZU) is connected to the primary heat source outflow line (L PQ , ab) fluidically connected and / or to the primary heat source discharge line (L PQ, ab) is fluidically connected, and the heat pump drain line (L WP , ab) with the primary heat source inflow line (LQ, ZU ) fluidically connected and / or connected to the primary heat source inflow line (L PQ , zu ) is fluidically connected, in particular by means of a primary heat source 3 / 2-way valve (21 .G).

4. Central heating system (1 ) according to claim 3, characterized in that a branch flow circuit inflow line (LSK, ZU) of the branch flow circuit (KAB) via the first 3-way connecting piece (26.1 ) or via the first 3 / 2-way valve (21.1 ) and via a primary heat source outflow line (L PQ , ab) arranged and / or interposed second 3-way connecting piece (26.2) with the primary heat source discharge line (L PQ , ab) fluidically connected and / or to the primary heat source discharge line (L PQ, ab), wherein a branch flow circuit discharge line (LSK, ab) of the branch flow circuit (KAB) is connected to the first 3 / 2-way valve (21.1 ) or to the first 3-way connecting piece (26.1 ) and via a third 3-way connecting piece (26.3) to the primary heat source inflow line (L P Q, ZU ) fluidically connected and / or connected to the primary heat source inflow line (L PQ , ZU ) is connected.

5. Central heating system (1) according to claim 4, characterized in that the primary heat source (2) has a primary heat source housing (2.G) and the domestic water storage tank (5) has a domestic water storage tank housing (5.G) arranged at a distance from the primary heat source housing (2.G), wherein the second and third 3-way connecting pieces (26.2, 26.3) are arranged between the primary heat source housing (2.G) and the domestic water storage tank housing (5.G).

6. Central heating system (1) according to one of claims 1 to 3, characterized in that a water-water heat exchanger (27), in particular a plate heat exchanger, is provided, in particular designed as a separate component, wherein a branch flow circuit inflow line (LSK, ZU) of the branch flow circuit (KAB) is fluidically connected to a first side (27.1) of the water-water heat exchanger (27) and / or is connected thereto, so that the heat transfer fluid (6) can be supplied to the first side (27.1) through the branch flow circuit inflow line (LSK, ZU), wherein a branch flow circuit outflow line (LSK, ab) of the branch flow circuit (KAB) is fluidically connected to the first side (27.1) and / or is connected thereto, so that the heat transfer fluid (6) through the branch flow circuit discharge line (LSK, ab) from the first side (27.1 ), whereby a service water discharge line (L Bw, ab) is fluidically connected and / or connected accordingly on the one hand to the domestic water storage tank (5) and on the other hand to a second side (27.2) of the water-water heat exchanger (27), so that the domestic water (11) can be fed through the domestic water discharge line (LBW, ab) from the domestic water storage tank (5) to the second side (27.2) with the aid of a domestic water pump (10), and wherein a domestic water inflow line (LBW, ZU) is fluidically connected and / or connected accordingly on the one hand to the domestic water storage tank (5) and on the other hand to the second side (27.2), so that the domestic water (11) can be fed through the domestic water inflow line (L B w, zu ) can be fed to the domestic hot water storage tank (5) from the second side (27.2).

7. Central heating system (1) according to claim 6, characterized in that a hot water pipe (17a) is connected to the domestic water drain pipe (L BW, ab) fluidically connected and / or to the domestic water discharge line (L BW , ab), whereby a cold water pipe (17b) is connected to the domestic water inlet pipe (L BW , to) and / or connected to the domestic water inlet pipe (L BW , ZU ) is connected.

8. Central heating system (1) according to claim 6 or 7, characterized in that the primary heat source (2) and the domestic water storage tank (5) have a common integral housing (28), wherein the primary heat source discharge line (L PQ , ab ) and the primary heat source inflow line (L PQ , zu ), in particular each completely, are arranged within the integral housing (28).

9. Central heating system (1) according to one of the preceding claims, characterized in that the heating pump (8) is connected to the water-air heat exchanger (4), the The circulation pump (9) is assigned to the heat pump (3) and the heat source pump (9b) is assigned to the primary heat source (2), namely it is arranged in a fluidically arranged region of the line system (7) assigned to the respective unit (2, 3, 4) or in a partial line region having the respective unit (2, 3, 4).

10. Central heating system (1) according to one of the preceding claims, characterized in that a temperature sensor (13.1) is arranged in a - viewed vertically - lower region of the domestic hot water storage tank (5) or adjacent to this - viewed vertically - lower region of the domestic hot water storage tank (5) for determining the actual domestic hot water temperature (TBI), wherein the temperature sensor (13.1) is connected to a heat pump control and / or regulating device (14) in terms of control, signaling and / or data technology, wherein the heat pump (3) is connected to the heat pump control and / or regulating device (14) in terms of control, 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 hot water temperature (TBI), in particular a central heating control and / or regulating device (12) is connected to the primary heat source (2) in terms of control for the purpose of controlling and / or regulating the same.

11. Central heating system (1) according to claim 10, characterized in that the temperature sensor (13.1) is arranged in or on a part of a domestic water inflow line (LBW. ZU) 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).

12. Central heating system (1) according to claim 10 or 11, 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 storage 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) for control / signal / and / or data purposes, 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).

13. Central heating system (1) according to claim 12, 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, in particular, calculated by the heat pump control and / or regulating device (14) 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, in particular, calculated by the heat pump control and / or regulating device (14) falls below a first limit temperature (TBIG),2) measured, determined and / or calculated second actual domestic hot water temperature (TB2) a second limit temperature (T. B 2G).

14. 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).

15. Central heating system (1) according to one of the preceding claims, characterized in that the line system (7) has at least one 4 / 2-way valve (20) which is arranged and / or functionally effective in terms of flow technology between the first 3 / 2-way valve (21.1) or the first 3-way connecting piece (26.1) on the one hand and the water-air heat exchanger (4) and the heat pump (3) on the other hand, with the aid of which the heat transfer fluid (6) can be conducted and / or guided to the water-air heat exchanger (4) or past the water-air heat exchanger (4) to the heat pump (3).

16. Central heating system (1) according to one of the preceding claims, characterized in that the line system (7) comprises a second and a third 3 / 2-way valve (21.2, 21.3) each with three connections and two switching positions, namely a second 3 / 2-way valve (21.2) arranged in particular in the heat exchanger inflow line (LWT, ZU) and / or interposed therein, and a third 3 / 2-way valve (21.2), arranged in particular in the heat pump inflow line (L W p, to) and / or interposed, 3 / 2-way valve (21.3), wherein the second 3 / 2-way valve (21.2) is connected to the first 3 / 2-way valve (21.1) or to the first 3-way connecting piece (26.1), the water-air Heat exchanger (4) and is fluidically connected to the third 3 / 2-way valve (21.3), wherein the third 3 / 2-way valve (21.3) is fluidically connected to the water-air heat exchanger (4), to the second 3 / 2-way valve (21.2) and to the heat pump (3), wherein by means of the second 3 / 2-way valve (21.2) a flow of the heat transfer fluid (6) from the first 3 / 2-way valve (21.1) or the first 3-way connecting piece (26.1) to the water-air heat exchanger (4) or to the third 3 / 2-way valve (21.3) is optionally possible, and wherein by means of the third 3 / 2-way valve (21.3) a flow of the heat transfer fluid (6) from the water-air heat exchanger (4) or from the second 3 / 2-way valve (21.2) to the heat pump (3).

17. Central heating system (1) according to one of the preceding claims, 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, to) at least in sections, the heat pump drain line (L W p, ab) at least in sections, of the circulation pump (9) and the 4 / 2-way valve (20), in particular of the second 3 / 2-way valve (21.2) and the third 3 / 2-way valve (21.3), at least two elements and / or components and respectively associated connections are arranged and / or formed on a first hydraulic module (22.1) forming a common structural unit.

18. Central heating system (1) according to one of the preceding claims, 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 branch flow circuit inflow line (LSK, ZU) at least in sections, the branch flow circuit outflow line (LSK, ab) at least in sections, the heat pump outflow line (L W p, ab) at least in sections, of the first 3-way connecting piece (26.1) and the first 3 / 2-way valve (21.1), at least two elements and / or components and respective associated connections are arranged and / or formed on a second hydraulic module (22.2) forming a common structural unit.

19. Central heating system (1) according to one of the preceding claims, characterized in that from the group of the following elements and / or components, namely the branch flow circuit inflow line (LSK, ZU) at least in sections, the branch flow circuit outflow line (LSK, ab) at least in sections, the water-water heat exchanger (27), the domestic water inflow line (LBW, ZU) at least in sections, the domestic water outflow line (LBW, ab) at least in sections and the Domestic water pump (10) at least two elements and / or components and respective associated connections are arranged and / or formed on a third hydraulic module (22.3) forming a common structural unit.

20. Central heating system (1) according to one of the preceding claims, characterized in that the heat pump control and / or regulating device (14) is connected to the central heating control and / or regulating device (12) for supplying energy to the heat pump control and / or regulating device (14) and / or that the heat pump control and / or regulating device (14) is connected to the heat pump (8) for controlling and / or regulating the heating pump (8) in terms of control technology and / or that the heat pump control and / or regulating device (14) is connected to the circulation pump (9) for controlling and / or regulating the heating pump (9) in terms of control technology and / or that the heat pump control and / or regulating device (14) is connected to the circulation pump (9) for controlling and / or regulating the domestic water pump (10) in terms of control technology and / or that the central heating control and / or regulating device (12) is connected to the domestic water pump (10) for controlling and / or regulating theHeat source pump (9b) is connected to the heat source pump (9b) for control purposes and / or that the heat pump control and / or regulating device (14) for controlling and / or regulating the first 3 / 2-way valve (21.1) is connected to the first 3 / 2-way valve (21.1) for control purposes and / or that the central heating control and / or regulating device (12) for controlling and / or regulating the primary heat source 3 / 2-way valve (21.G) is connected to the primary heat source 3 / 2-way valve (21.G) for control purposes, that the heat pump control and / or regulating device (14) for controlling and / or regulating the 4 / 2-way valve (20), in particular the second and third 3 / 2-way valves (21.2 and 21.3), is connected to the 4 / 2-way valve (20) for control purposes and / or that the heat pump control and / or regulating device (14) is provided with an outside temperature sensor (13.a) for determining an outside temperature (T a) is connected in terms of control, signaling and / or data technology.

21. Method for operating and / or controlling and / or regulating a central heating system (1) according to one of claims 1 or according to one of claims 3 to 20, wherein the 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, is selectively conveyable and / or is conveyed by means of the at least one pump (8, 9, 9b) through a part of a line system (7) and through the water-air heat exchanger (4) in order to heat the water-air heat exchanger (4) by means of the water-air heat exchanger (4). Air heat exchanger (4) to heat the environment adjacent to it, wherein the heat transfer fluid (6) is selectively conveyed by means of the at least one pump (8, 9, 9b) through a further part of the line 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 conveyable and / or is conveyed by means of the at least one pump (8, 9, 9b) through a further part of the line system (7) and through the primary heat source (2) in order to heat the heat transfer fluid (6) by means of the primary heat source (2), characterized in that the first 3 / 2-way valve (21.1) is switched into a first switching position and thus a flow of the heat transfer fluid (6) from a branch flow circuit outflow line (LSK, ab) to a region of the heat exchanger inflow line (LWT, ZU) which is fluidically facing the water-air heat exchanger (4) and / or the heat pump (3) is enabled in order to supply the heat transfer fluid (6) to the water-air heat exchanger (4) and / or the heat pump (3) from a primary heat source inflow line (L. PQ , zu) or from the first side (27.1) of a water-water heat exchanger (27), or that the first 3 / 2-way valve (21.1) is switched to a second switching position and thus a flow of the heat transfer fluid (6) from a region of the heat exchanger inflow line (LWT, zu) fluidically upstream of the first 3 / 2-way valve (21.1) to the region of the heat exchanger inflow line (LWT, ZU) fluidically facing the water-air heat exchanger (4) and / or the heat pump (3) is made possible in order to supply the heat transfer fluid (6) to the water-air heat exchanger (4) and / or the heat pump (3) from a primary heat source outflow line (LPQ, ab) and thus to fluidically bypass the heating line (LHZ) and / or the water-water heat exchanger (27).

22. A method for operating and / or controlling and / or regulating a central heating system (1) according to one of claims 2 to 20, wherein the 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, is selectively conveyable and / or is conveyed by means of the at least one pump (8, 9, 9b) through a part of a line system (7) and through the water-air heat exchanger (4) in order to heat the environment adjacent to the water-air heat exchanger (4) by means of the water-air heat exchanger (4), wherein the heat transfer fluid (6) is selectively conveyed by means of the at least one pump (8, 9, 9b) through a further part of the line system (7) and through the heat pump (3) in order to heat, wherein the heat transfer fluid (6) is selectively pumped by means of the at least one pump (8, 9,9b) is conveyable and / or is conveyed through a further part of the pipe system (7) and through the primary heat source (2) in order to convey the heat transfer fluid (6) by means of the, Primary heat source (2), characterized in that the first 3 / 2-way valve (21.1) is switched to a first switching position and thus a flow of the heat transfer fluid (6) from a region of the heat pump discharge line (LWP, ab) fluidically upstream of the first 3 / 2-way valve (21.1) into a branch flow circuit inflow line (LSK, ZU) is enabled in order to supply the heat transfer fluid (6) from the heat pump (3) to a heating line (LHZ) or the first side (27.1) of a water-water heat exchanger (27), or that the first 3 / 2-way valve (21.1) is switched to a second switching position and thus a flow of the heat transfer fluid (6) from the region of the heat pump discharge line (LWP, ab) fluidically upstream of the first 3 / 2-way valve (21.1) to a Primary heat source inflow line (L PQ , zu) is made possible in order to supply the heat transfer fluid (6) to the primary heat source (2) and in particular thus to bypass the heating line (LHZ) and / or the water-water heat exchanger (27) in terms of flow.

23. Method according to claim 21 or 22, characterized in that with the aid of the temperature sensor (13.1) the first 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) as a function of the determined first actual domestic water temperature (TBI).

24. Method according to claim 23, characterized in that 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 the second, preferably average, actual domestic water temperature (TBZ) is measured, determined and / or calculated by means of the 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 (TBZ) 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 (TBZ).

25. Method according to claim 24, characterized in that the heat pump (3) is controlled by the heat pump control and / or regulating device (14) to heat the Heat transfer fluid (6) is operated and / or activated, and wherein the first 3 / 2-way valve (21.1) is switched into its first switching position with the aid of the heat pump control and / or regulating device (14) 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 the first limit temperature (TBIG), and / or 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), and in particular the primary heat source 3 / 2-way valve (21.G) is switched into a first switching position for connecting the heating line (LHZ) to the primary heat source (2) by means of the central heating control and / or regulating device (12) and / or the heat source pump (9b) is operated and / or activated by means of the central heating control and / or regulating device (12) when the second actual domestic water temperature (T. B 2) the second limit temperature (T B 2G), in particular the heat pump control and / or regulating device (14) and the central heating control and / or regulating device (12) operate independently of one another and / or are not connected to one another in terms of control technology.

26. Method according to claim 25, characterized in that the first and second limit temperatures (TBIG, T B2G) 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), in particular the primary heat source 3 / 2-way valve (21. G) is switched to its first switching position, and in particular the heat source pump (9b) is only operated and / or activated, when a heat requirement of the domestic hot water storage tank (5) exceeds a heat quantity that can be provided by means of the heat pump (3) at maximum output of the heat pump (3).

27. Method according to one of claims 21 to 26, 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 regulation device (14), in particular additionally, as a function of a first actual heat transfer fluid temperature (Twi) formed at the outlet of the heat pump (3) and / or as a function of a first desired heat transfer fluid temperature (Twi.soii) predetermined for the outlet of the heat pump (3).

28. Method according to one of claims 21 to 27, characterized in that the primary heat source (2) and / or the heat source pump (9b) is / are controlled by means of the central heating control and / or regulating device (12) in dependence on a second - within or in the area of ​​the primary heat source (2) forming - actual heat transfer fluid temperature (TW2) and / or depending on a second - for the inner area of ​​the primary heat source (2) - predetermined target heat transfer fluid temperature (T W 2, son) controlled and / or regulated.

29. Method according to claim 28, 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 operated and / or activated with the aid of the central heating control and / or regulating device (12) for heating the heat transfer fluid (6) only when a heat requirement of the central heating system (1), in particular a heat requirement of the water-air heat exchanger (4) and / or the domestic hot water storage tank (5), exceeds a heat quantity that can be provided by means of the heat pump (3) at maximum output of the heat pump (3).

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