Retrofit kit for an existing central heating system, and method for retrofitting an existing central heating system using a retrofit kit

Abstract

The invention relates to a retrofit kit (1) for an existing central heating system (2) and to a method for retrofitting an existing central heating system (2) using a retrofit kit (1). The central heating system (2) has at least one primary heat source (3) which can be operated with fuels, in particular a boiler and / or a gas heater, at least one heat exchanger (4), preferably a heating element or a radiator for heating a building, and at least one service water reservoir (5), said retrofit kit (1) and / or central heating system (2) having at least one electrically operatable heat pump (11). The installation of the retrofit kit (1) and the integration thereof for control and / or regulating purposes are simplified in that the retrofit kit (1) has a temperature sensor (13.1) and a heat pump control and / or regulating device (14). The temperature sensor (13.1) is connected or can be connected to the heat pump control and / or regulating device (14) for control and / or signaling purposes and / or so as to transmit data. The heat pump (11) is connected or can be connected to the heat pump control and / or regulating device (14) for control purposes, and the heat pump control and / or regulating device (14) is designed such that the heat pump (11) can be controlled and / or regulated on the basis of the actual service water temperature (TB1), which is measured by means of the temperature sensor (13.1) in a lower region of the service water reservoir (5), when viewed vertically, or adjacently to the lower region of the service water reservoir (5), when viewed vertically.

Description

[0001] Retrofit kit for an existing central heating system and a method for retrofitting an existing central heating system using a retrofit kit

[0002] The invention relates to a retrofit kit for an existing central heating system having the features of the preamble of patent claim 1 and to a method for retrofitting an existing central heating system by means of a retrofit kit having the features of the preamble of patent claim 14.

[0003] The central heating systems currently in use and / or already known or already present in buildings typically comprise a primary heat source operable using fuel, in particular a boiler and / or a gas boiler, a heat exchanger, preferably a heater or radiator for heating a building, and a domestic hot water storage tank. A heat transfer fluid, in particular water, can be heated by means of the primary heat source. The heat transfer fluid, in particular previously heated, can be conveyed through or to the heat exchanger by means of a heating pump. The heat transfer fluid can be conveyed to the domestic hot water storage tank by means of a storage pump for heating domestic hot water temporarily stored in the domestic hot water storage tank, in particular for heat transfer from the heat transfer fluid to the domestic hot water through or adjacent to the domestic hot water storage tank.The primary heat source has a central heating control and / or regulation device for its control and / or regulation.

[0004] In order to save fuel during operation of the central heating system described above, such central heating systems can also be expanded to include an electrically operated heat pump. Thus, a retrofit kit and / or a correspondingly expanded central heating system can then comprise at least one electrically operated heat pump. The heat transfer fluid can then also be heated with the aid of the heat pump. The heat transfer fluid can then be conveyed to the heat pump for heating, in particular with the aid of a circulation pump, or is conveyed through / through the heat pump, in particular with the aid of the circulation pump. The heat transfer fluid can then also be conveyed through or to the primary heat source by means of the heating pump, in particular the circulation pump, and / or the storage pump, wherein the heat transfer fluid can also be heated accordingly by the primary heat source.DE 30 49 132 C2 shows a known, in this case oil-fired, central heating system with a boiler as the primary heat source and an integrated domestic hot water boiler. A line leads from the boiler to a connection of a four-way mixing valve (four-way cock). From another connection of the four-way mixing valve, a heat transfer fluid, heated, for example, by the boiler, can be fed to the heat exchangers / radiators for heating a building by means of a heating pump. Another line leads from the radiators back to the four-way mixing valve. This standard circuit of many central heating systems is now to be expanded with a heat pump, for example of the air / water type. The heat pump is installed as part of a retrofit kit in the central heating system, fluidically in series with the boiler.The retrofit kit features a mechanically or electromagnetically operated shut-off valve, which, when installed, can be used to bypass the heat pump. The heat pump can be easily and seamlessly connected to the existing central heating system. The existing four-way mixing valve can continue to be used. The retrofit kit also features a circulation pump, which, when installed, supplies the heat transfer fluid to the heat pump.

[0005] The domestic hot water boilers installed in boilers for heating domestic water typically have a small storage capacity, so the domestic water must be heated quickly, i.e., at high power, during operation of the central heating system. However, such high power requires the operation of the boiler, especially in addition to the heat pump, so that overall, there is still a high fuel demand throughout the year, which is disadvantageous and very costly.

[0006] DE 32 30 940 A1 shows a central heating system with a primary heat source designed as a boiler, a heat pump, and a domestic hot water storage tank for heating domestic hot water. Each of these units is assigned a pump and a heating circuit. A heat transfer fluid can be supplied to the heat pump via a heat pump inlet line, also called a return line, from, for example, an underfloor heating system. Several valves are provided so that different operating modes of the central heating system can be implemented using the boiler and the heat pump. The domestic hot water storage tank or the underfloor heating system can also be supplied with heated heat transfer fluid, in particular using the heat pump alone. The domestic hot water storage tank or the underfloor heating system can also be supplied with heated heat transfer fluid using the boiler alone.Simultaneous operation of the heat pump and boiler is also conceivable in order to supply the underfloor heating with heated heat transfer fluid using the heat pump and the boiler. In this case, the boiler is also supplied with the heat transfer fluid heated by the heat pump. The heat pump and boiler are thus connected in series via the valves. For economic reasons, the heat pump is not operated at outside temperatures below 5°C. 30-50% of the heat requirement can be generated by the heat pump. A ready-to-install coupling unit, i.e. a hydraulic module, is provided, in which all connection connections for linking the heating boiler with the heat pump and the associated heating circuits are located.The hydraulic module is either delivered fully connected and located directly on the back of the boiler or the hydraulic module is delivered as a fully installed hydraulic module, which is then connected as a whole to the corresponding connections on the boiler.

[0007] In particular, the heating of the domestic water in the domestic water storage tank is not yet optimally designed. Simultaneous heating of the domestic water by the heat pump and the boiler is not possible with the valves and heating circuits described above. In particular, even early on, especially since the heat pump is only designed to cover 30-50% of the heat demand, the domestic water is heated solely by the boiler using cost-intensive fuels, resulting in fuel requirements that increase throughout the year.

[0008] EP 2 322 880 B1 discloses a heat pump system for an apartment building with several residential units. Each residential unit has a heat pump. The heat pumps are supported by auxiliary heating devices. These auxiliary heating devices can be, for example, conventional natural gas condensing boilers, namely so-called gas boilers. The auxiliary heating devices are thus designed in particular as primary heat sources. The heat pumps can preheat a heat transfer fluid, which is then further heated in the serially connected auxiliary heating devices. By means of a heating circuit, the heat transfer fluid can be fed to a heat exchanger, in particular a radiator or heating element, for heating a residential unit. By means of a provided overflow valve, the heat transfer fluid can optionally be bypassed by the heat exchanger. As an alternative to serial connection, the auxiliary heating devices could also be connected in parallel to the heat pumps.Depending on the required heating output, the heat pump can be operated monovalently (without an additional booster heater) or bivalently (with an additional heater). In monovalent operation, the residential unit is supplied with heat via the heat exchanger(s) / radiators and with hot domestic water by the heat pump alone. If the required heating output is higher than the maximum heating output of the heat pump, the heat pump is operated bivalently. A distinction is made here between bivalent-alternative and bivalent-parallel operation. In bivalent-alternative operation, the heat pump covers the heating requirements of the residential unit alone up to a defined outside temperature. Below this defined outside temperature, the booster heater covers the heating requirements alone. In bivalent-parallel operation, the heat pump covers the required heating output up to a defined outside temperature alone.Below this outside temperature, the auxiliary heater is switched on, so that both heat generators (heat pump and auxiliary heater) supply the living unit with heat simultaneously. In general, the lower the outside temperature, the higher the auxiliary heater's share of the total heat supply. When using an air-to-brine heat pump, above a defined minimum outside temperature, the auxiliary heater supplies the living unit with heat alone, since it is not economically viable to absorb heat from the outside air. In this case, the heat pump is also designed as a connection bracket for the auxiliary heater, allowing a commercially available auxiliary heater to be mounted on the heat pump.

[0009] DE 26 13 967 A1 discloses an installation element / hydraulic module for a bivalent central heating system consisting of a heat pump and auxiliary heating (oil, gas, or electric heating). The auxiliary heating is thus designed, in particular, as a primary heat source. Several connections for the heat pump, the auxiliary heating, and a domestic hot water storage tank are arranged in or on the hydraulic module. Furthermore, several valves are arranged in or on the hydraulic module, e.g., a multi-way reversing valve for selectively supplying a heat exchanger for heating a building or another heat exchanger for heating domestic hot water. Furthermore, the piping for the components for the various heating circuits is arranged in or on the hydraulic module.

[0010] In the central heating systems known in the prior art, the heating of the domestic water in the domestic water storage tank is not yet optimally designed if both a primary heat source and / or a heat pump, especially a retrofitted one, are provided for heating the domestic water. As already described at the beginning, a large amount of fuel is required throughout the year, since the primary heat source must be operated for a long time to ensure that the actual domestic water temperature is above a certain limit temperature. Further problems arise, especially if a heat pump is to be retrofitted and this was not already planned as a component in the design of the central heating system. In this case, for example,Very complex modifications to a central heating control and / or regulation system are necessary in order to then be able to control and / or regulate the heat pump with this central heating control and / or regulation system. Furthermore, the control and / or regulation of the heat pump and the primary heat source must then be coordinated with each other, particularly in the central heating control and / or regulation system. This is very complex work, which must be carried out repeatedly, especially when a heat pump is to be retrofitted to an existing central heating system, since existing central heating systems often have significant specific differences from one another. Ultimately, therefore, retrofitting an existing central heating system is problematic as well as very labor-intensive and / or costly.

[0011] The invention is therefore based on the object of specifying a retrofit kit for an existing central heating system and / or a method for retrofitting an existing central heating system or of designing and / or further developing it in such a way that fuel consumption and the associated costs are reduced and / or that the retrofit kit can be easily and cost-effectively integrated into the existing central heating system in terms of control and / or regulation and / or retrofitting is possible without great effort and / or without great installation costs.

[0012] This problem underlying the invention is now solved - for the retrofit kit - initially by a retrofit kit for an already existing central heating system with the features of patent claim 1.

[0013] One aspect of the invention is, first and foremost, that the retrofit kit comprises a temperature sensor and a heat pump control and / or regulating device, wherein the temperature sensor is or can be connected to the heat pump control and / or regulating device in terms of control, signal, and / or data technology, wherein the heat pump is and / or can be connected to the heat pump control and / or regulating device in terms of control. A further aspect of the invention is that the heat pump control and / or regulating device is designed and / or constructed such that the heat pump can be controlled and / or regulated as a function of an actual domestic hot water temperature measured by means of the temperature sensor in a - viewed vertically - lower area of ​​the domestic hot water storage tank or adjacent to this - viewed vertically - lower area of ​​the domestic hot water storage tank.

[0014] Because the retrofit kit now initially features a separate heat pump control and / or regulation device for the heat pump, the central heating control and / or regulation device in particular does not need to be adapted at all, or if so, only to a very limited extent. In a preferred embodiment, the existing heat pump control and / or regulation device can, for example, be designed depending on a specific heat pump, so that, in particular, heat pumps of the same design and output can then also be retrofitted with the same heat pump control and / or regulation devices to a wide variety of existing central heating systems. This initially simplifies the assembly of the components of the retrofit kit and / or avoids adapting the heat pump control and / or regulation device to differently designed specific heat pumps, but the latter is nevertheless conceivable.

[0015] Saving fuel and simplifying the control integration of the components into the existing central heating system is now initially achieved with the help of the aforementioned temperature sensor. The desired temperature of the domestic hot water can then be controlled and / or regulated particularly well using the retrofitted or existing heat pump and the retrofitted heat pump control and / or regulation device. Because the temperature sensor is located in the - vertically viewed - lower area of ​​the domestic hot water tank or adjacent to this - vertically viewed - lower area of ​​the domestic hot water tank, the heat pump can then be controlled and / or regulated particularly quickly, in particular without a long time delay, when fresh and therefore cold orColder (new) domestic water is then fed back into the domestic water storage tank, particularly when domestic water is withdrawn from the domestic water storage tank (e.g., for a domestic shower), because the "new" domestic water flows around the temperature sensor before mixing with the remaining domestic water still present in the domestic water storage tank. The lower section of the domestic water storage tank, viewed vertically, is preferably located in a lower third, especially a lower quarter, of the total height of the domestic water storage tank, or is designed accordingly.

[0016] 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 is or can then be drawn from the domestic water storage tank, for example, for a domestic shower, cooking, or dishwashing process, with new fresh water then being added to the domestic water storage tank to refill it. The designation of this storage tank as a “domestic water storage tank” therefore does not mean that already 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.

[0017] In a highly preferred embodiment of the retrofit kit, the temperature sensor can be mounted, particularly by means of a T-piece, in or on a portion of a domestic water inlet line formed between an inlet valve and an inlet connection of the domestic water storage tank. Such a T-piece is then also part of the retrofit kit.

[0018] By opening the inlet valve, fresh domestic water can be supplied to the domestic water storage tank via the domestic water inlet line and the inlet connection. Up to the inlet valve (from 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. Installing the temperature sensor on the domestic water inlet line is particularly simple, as the domestic water storage tank does not require any structural modifications, and the temperature sensor can still be installed, especially with direct contact to the freshly supplied domestic water.In particular, a section of the domestic water supply line can also be cut out and replaced with a T-piece, in which case the temperature sensor is then arranged in the branch of the T-piece and preferably connected to the T-piece with a sealing cap. Alternatively, 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.In this case, the installation of a temperature sensor, which is to be arranged externally on or in a housing / shell area of ​​the domestic hot water storage tank or on the domestic hot water inlet line, would be particularly simple and quick to carry out.

[0019] In a preferred embodiment of the retrofit kit, the aforementioned temperature sensor is designed as a first temperature sensor for determining a first actual domestic water temperature. A second temperature sensor is 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 also include a signal and / or data connection.

[0020] The heat pump control and / or regulating device is now designed and / or constructed such that the heat pump can be operated and / or activated with the aid of the heat pump control and / or regulating device to heat the heat transfer fluid when the first actual domestic water temperature measured, determined and / or calculated, in particular by the heat pump control and / or regulating device, with the aid of the first temperature sensor falls below a first limit temperature.

[0021] The central heating control and / or regulating device is designed and / or constructed such that the primary heat source can be operated and / or activated with the aid of the central heating control and / or regulating device to heat the heat transfer fluid when the second actual domestic water temperature measured, determined and / or calculated with the aid of the second temperature sensor falls below a second limit temperature.

[0022] In a very preferred embodiment, the first and second limit temperatures are selected in particular such that the primary heat source can be 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 domestic hot water storage tank exceeds a heat quantity that can be provided by the heat pump at maximum output of the heat pump.

[0023] Therefore, no further complex and / or complicated adjustments are necessary to control the central heating system, in particular the heating circuit for heating domestic water. The central heating control and / or regulating device and the heat pump control and / or regulating device operate essentially independently of one another. In particular, the first limit temperature is entered on / in the heat pump control and / or regulating device or is already defined there, and / or the second limit temperature is entered on / in the central heating control and / or regulating device accordingly or is already defined there. The retrofit kit is therefore particularly quick to install and can be easily integrated into the central heating system in terms of control and / or regulating technology.

[0024] The central or upper section of the domestic hot water tank (vertically speaking) is preferably located in the upper two-thirds, particularly in the upper half, of the total height of the domestic hot water tank, or is designed accordingly. Furthermore, the clever or specific arrangement of the two temperature sensors enables optimal control and / or regulation of the entire central heating system with a view to minimizing fuel consumption for the primary energy source.The first temperature sensor is arranged - viewed essentially vertically - below the second temperature sensor. Due to the temperature stratification of the domestic water that develops within the domestic water storage tank, a lower actual domestic water temperature can be determined using the first temperature sensor than using the second temperature sensor. In fact, a change in temperature, in particular a decrease in temperature, can be determined earlier in time using the first temperature sensor than with the second temperature sensor. This provides the basis for optimally controlling the heat pump, in particular for preferential operation and for activating and / or operating the primary heat source only when the power or demand provided by the heat pump has been reached.The amount of heat is no longer sufficient, in particular to cover the demand for heating the domestic hot water storage tank, so that the demand for fuels for the primary heat source can be minimized or at least reduced.

[0025] The particularly fast controllability and / or regulation of the heat pump described above therefore also means in particular that the heat pump can be activated and / or operated before the primary heat source, provided that a corresponding heat requirement of the domestic hot water storage tank is determined using the first temperature sensor. A further heat requirement of the domestic hot water storage tank is only determined at a later time using the second temperature sensor. In particular, the first and second limit temperatures are selected and / or set accordingly. 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.

[0026] Preferably, the heat exchanger and the heat pump are connected and / or switchable in series with respect to the primary heat source.

[0027] Preferably, an output connection of the heat pump is fluidically connected and / or connectable to an input connection of the primary heat source. Due to the aforementioned fluidic series connection, the entire heat transfer fluid heated by the heat pump can then also be supplied to the primary heat source during operation of the installed and / or existing heat pump. This further reduces the fuel requirement of the primary heat source, since the primary heat source does not need to be activated and / or operated at all or only rarely due to the heat transfer fluid being supplied at a relatively high temperature. Therefore, a desired temperature of the heat transfer fluid can usually already be achieved within or in the vicinity of the primary heat source, namely by heating the heat transfer fluid by means of the heat pump, without the primary heat source having to be operated.

[0028] A heat exchanger inflow line is advantageously fluidically connected, or connectable and / or correspondingly connected, on the one hand, to the primary heat source and, on the other hand, to the heat exchanger in order to supply the heat transfer fluid to the heat exchanger by means of the heating pump through the heat exchanger inflow line, in particular wherein the heat exchanger inflow line is partly already present and partly part of the retrofit kit, in particular part of a hydraulic module. A heat pump inflow line is fluidly connected, or connectable and / or correspondingly connected, on the one hand, to the heat exchanger and, on the other hand, to the heat pump in order to supply the heat transfer fluid to the heat pump through the heat pump inflow line, in particular wherein the heat pump inflow line is partly already present and partly part of the retrofit kit, in particular part of the hydraulic module.A heat pump drain line is fluidically connected or connectable and / or connected accordingly to the heat pump on the one hand and to the primary heat source on the other hand in order to supply the heat transfer fluid to the primary heat source through the heat pump drain line, in particular wherein the heat pump drain line is partly already present and partly part of the retrofit kit, in particular part of a hydraulic module.

[0029] This allows for particularly easy integration of the retrofit kit into the existing central heating system. The various lines of the retrofit kit are pre-assembled as required. Using these lines, the fluidic series connection of the heat exchanger, heat pump, and primary heat source is particularly easy to achieve. The lines mentioned here can be formed using pipes and / or hoses and / or flow channels formed in housings.

[0030] In a further embodiment of the retrofit kit, the retrofit kit has at least one valve, by means of which the heat transfer fluid can be directed and / or guided either from the primary heat source to the heat exchanger or past the heat exchanger to the heat pump.

[0031] By means of the appropriately mounted valve, two different heating circuits can then be created depending on the valve position. In a first heating circuit, a flow of the heat transfer fluid from the primary heat source, via the valve, via the heating pump, via the heat exchanger, via the heat pump, via the circulation pump and back to the primary heat source can be realized. In a second heating circuit, a flow of the heat transfer fluid from the primary heat source, via the valve, via the heat pump, via the circulation pump and back to the primary heat source can be realized. In a third heating circuit, a flow of the heat transfer fluid from the primary heat source, via the domestic hot water storage tank, via the storage pump and back to the primary heat source can also be realized. In the primary heat source, a distribution system for the heat transfer fluid is preferably provided, in particular flow channels through which the heat transfer fluid can flow.to which the heating circuits are each connected and / or connectable. The heat exchanger inlet line and the heat pump outlet line, as well as a line leading to the domestic hot water storage tank and a line returning from the domestic hot water storage tank, are connected and / or connectable to the primary heat source, in particular to such a distribution system, or are fluidly connected to the primary heat source, in particular a boiler.

[0032] The retrofit kit further preferably comprises two 3 / 2-way valves, each with three connections and two switching positions, namely a first 3 / 2-way valve, which can be arranged or arranged and / or interposed in particular in the heat exchanger inflow line, and a second 3 / 2-way valve, which can be arranged or arranged and / or interposed in particular in the heat pump inflow line. The first 3 / 2-way valve is fluidically connectable to the primary heat source and to the heat exchanger, and is fluidically connectable or connected accordingly to the second 3 / 2-way valve. The second 3 / 2-way valve is fluidically connectable or connectable to the heat exchanger, is fluidically connectable or connectable or connected accordingly to the heat pump, and is fluidically connectable or connected accordingly to the first 3 / 2-way valve.When connected, the first 3 / 2-way valve allows the heat transfer fluid to flow either from the primary heat source to the heat exchanger or from the primary heat source to the second 3 / 2-way valve. When connected, the second 3 / 2-way valve allows the heat transfer fluid to flow either from the heat exchanger to the heat pump or from the first 3 / 2-way valve to the heat pump.

[0033] Using these two 3 / 2-way valves, the heating circuits described above can also be implemented. The two 3 / 2-way valves are also inexpensive to purchase and easy to control and / or regulate. The two 3 / 2-way valves can be switched from a basic position to a switching position, preferably by means of an electric actuator, counteracting the spring force applied by a mechanical spring when the actuator is energized. The two 3 / 2-way valves are then installed in such a way that the two 3 / 2-way valves do not need to be energized for an extended period during operation of the central heating system, thus also saving energy.

[0034] Preferably, at least two elements and / or components from the group of elements / 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 circulation pump, the heat pump control and / or regulating device and the valve, in particular the first 3 / 2-way valve and the second 3 / 2-way valve, but in particular the heat exchanger inflow line in sections, the heat pump inflow line in sections, the heat pump outflow line in sections, the first 3 / 2-way valve and the second 3 / 2-way valve, preferably all of the aforementioned elements and / or components, and respectively associated connections are arranged and / or formed on a hydraulic module forming a common structural unit.

[0035] Using such a hydraulic module, the installation of the retrofit kit on the central heating system can be greatly simplified. In particular, the otherwise common installation errors can be avoided, as the specific shape and / or design of the hydraulic module predetermines certain arrangements of elements and / or components. The hydraulic module is advantageously pre-assembled, for example, in a factory or at a heating engineer's, so that the installation time for the end customer who operates the central heating system and wishes to retrofit it accordingly can be significantly reduced.

[0036] In a further embodiment of the retrofit kit, the hydraulic module comprises a frame for connecting the hydraulic module to a building wall and / or the primary heat source. The hydraulic module, in particular the frame, is then preferably adapted to the specific design of the primary heat source, so that the hydraulic module, in particular the frame, can be easily mounted on the primary heat source or on a building wall.

[0037] In an advantageous embodiment of the retrofit kit, the part of the heat exchanger inflow line associated with the retrofit kit has a first connection for supplying the heat transfer fluid to the hydraulic module and a second connection for discharging the heat transfer fluid from the hydraulic module. The part of the heat pump inflow line associated with the retrofit kit has a third connection for supplying the heat transfer fluid to the hydraulic module and a fourth connection for discharging the heat transfer fluid from the hydraulic module. The part of the heat pump outflow line associated with the retrofit kit has a fifth connection for supplying the heat transfer fluid to the hydraulic module and a sixth connection for discharging the heat transfer fluid from the hydraulic module.Preferably, the part of the heat exchanger inlet line associated with the retrofit kit and / or the part of the heat pump inlet line associated with the retrofit kit and / or the part of the heat pump outlet line associated with the retrofit kit are each formed in the hydraulic module. The connections are aligned to each other in such a way that a simple, quick connection to the parts of the lines associated with the central heating system is possible.

[0038] The object underlying the invention is also achieved by a method for retrofitting an existing central heating system by means of the above-described retrofit kit according to patent claim 14.

[0039] One aspect of the invention then essentially lies in the fact that the first temperature sensor is mounted and / or arranged in a lower area of ​​the domestic hot water tank (viewed vertically) or adjacent to this lower area of ​​the domestic hot water tank (viewed vertically). With the help of this first temperature sensor, the actual domestic hot water temperature of the domestic hot water in the lower area of ​​the domestic hot water tank can be determined accordingly.

[0040] The retrofitting process is initially very easy to install. The arrangement of the temperature sensor in the lower (vertical) area of ​​the domestic hot water tank leads to a cost-effective, uncomplicated, and particularly simple control and / or regulation of the entire central heating system, as already described. Furthermore, due to this arrangement of the temperature sensor in the lower (vertical) area of ​​the domestic hot water tank, only minor adjustments and / or settings are necessary to the existing heat pump control and / or regulation device, as well as to the existing central heating control and / or regulation device. In particular, no further adjustments and / or settings are necessary to ensure optimal operation of the central heating system.

[0041] Preferably, the first temperature sensor is then connected to the heat pump control and / or regulating device for control, signal, and / or data purposes. The measured values ​​and / or signals determined by the first temperature sensor can then be transmitted to the heat pump control and / or regulating device. An actual domestic water temperature associated with the respective measured value / signal is determined and / or calculated either by means of the appropriately designed temperature sensor itself or by means of the heat pump control and / or regulating device. It is also conceivable, however, that the first temperature sensor in the retrofit kit is already connected to the heat pump control and / or regulating device for control, signal, and / or data purposes, in particular via a signal line. At this point, it should also be mentioned that corresponding wireless connections between the components are also conceivable.

[0042] Advantageously, if the heat pump is part of the existing central heating system, the heat pump is connected to the heat pump control and / or regulation device via the control system. Alternatively, if the heat pump is part of the retrofit kit, the heat pump is connected to the heat pump control and / or regulation device via the control system, or is already connected accordingly.

[0043] In particular, the heat pump control and / or regulating device could also be arranged on the hydraulic module. Furthermore, it is conceivable for the heat pump control and / or regulating device to be mounted separately, e.g., on a building wall. Alternatively, the heat pump and the heat pump control and / or regulating device could also be designed as a single structural unit.

[0044] In a further embodiment of the method, the storage pump is then connected to the heat pump control and / or regulating device for control purposes. Under certain circumstances, an existing control connection between the storage pump and the central heating control and / or regulating device is released and / or interrupted beforehand. The storage pump can then be controlled and / or regulated, in particular by means of the heat pump control and / or regulating device, so that, in particular, coordinated operation between the heat pump and the storage pump is possible. In particular, the heat pump and the storage pump can then be activated and / or operated simultaneously and deactivated again at the same time. In particular, the third heating circuit described above for heating the domestic water can then be operated accordingly, namely, in particular, a coordinated operation of the heat pump and the storage pump can take place.

[0045] Further preferably, the heat pump is also connected to the heat pump control and / or regulating device for control purposes. Under certain circumstances, an existing control connection between the heat pump and the central heating control and / or regulating device is previously disconnected and / or interrupted. The heat pump can then be controlled and / or regulated by means of the heat pump control and / or regulating device, thereby enabling coordinated operation between the heat pump and the heat pump. In particular, the heat pump and the heat pump can be activated and / or operated simultaneously and deactivated again simultaneously. In particular, coordinated operation, including coordinated operation of the respective heating circuits, is also enabled.

[0046] In a further embodiment of the method, the valve is connected to the heat pump control and / or regulating device for control purposes. In particular, if the valve and the heat pump control and / or regulating device are arranged on the hydraulic module, the control connection is already established in advance in a factory or at a heating engineer's, so that this assembly step does not need to be performed by the end customer.

[0047] In another highly preferred embodiment of the method, the first 3 / 2-way valve and the second 3 / 2-way valve are each connected to the heat pump control and / or regulating device for control purposes. In particular, if the first and second 3 / 2-way valves and the heat pump control and / or regulating device are arranged on the hydraulic module, the control connection is implemented beforehand in a factory or by a heating engineer, so that this assembly step does not need to be performed by the end customer.

[0048] In a preferred embodiment of the method, an outside temperature sensor is mounted in an outdoor area surrounding a building, wherein the outside temperature sensor is or will be connected to the heat pump control and / or regulation device for control, signal, and / or data purposes. Thus, the components connected to the heat pump control and / or regulation device can be controlled and / or regulated depending on the respective outside temperature.

[0049] In principle, when the central heating system is operated with the retrofit kit, more control and regulation tasks are carried out by means of the heat pump control and / or regulation device than with the central heating control and / or regulation device, whereby some control and regulation tasks are carried out by means of the heat pump control and / or regulation device which were carried out by means of the central heating control and / or regulation device before the integration of the retrofit kit.

[0050] Advantageously, the first limit temperature or a table and / or a formula for determining the first limit temperature is entered into the heat pump control and / or regulation device and / or is already stored there. The second limit temperature or a table and / or a formula for determining the second limit temperature is entered into the central heating control and / or regulation device and / or is already stored there.

[0051] In particular, by entering certain respective limit temperatures or by the presence of desired limit temperatures, a coordination of the control and / or regulation of the heat pump with the control and / or regulation of the primary heat source is achieved or realized.

[0052] To simplify the method, the first and / or second limit temperatures are stored as constant values ​​in the heat pump control and / or regulating device and / or in the central heating control and / or regulating device, so that the first and second limit temperatures are independent of the outside temperature. In particular, the first limit temperature is stored in the heat pump control and / or regulating device and / or is set there, while the second limit temperature is stored in the central heating control and / or regulating device and / or is set there.

[0053] In an advantageous embodiment of the method, the part of the heat exchanger inflow line belonging to the retrofit kit is connected to the existing part of the heat exchanger inflow line by means of the first and second connections of the hydraulic module. The part of the heat pump inflow line belonging to the retrofit kit is connected to the existing part of the heat pump inflow line by means of the third and fourth connections of the hydraulic module. The part of the heat pump outflow line belonging to the retrofit kit is connected to the existing part of the heat pump outflow line by means of the fifth and sixth connections of the hydraulic module. The heat transfer fluid can then be supplied to the heat exchanger via the heat exchanger inflow line. The heat transfer fluid can then also be supplied to the heat pump via the heat pump inflow line and to the primary heat source via the heat pump outflow line.Parts of flange connections, for example, are used as connections, which are connected, in particular screwed, to corresponding counterparts arranged and / or arrangeable on the existing parts of the lines. Alternatively, the lines of the retrofit kit could also be connected to the existing parts of the lines in another way, e.g. welded and / or soldered. There are now a multitude of possibilities for advantageously designing and developing the retrofit kit for an existing central heating system and the method for retrofitting an existing central heating system using a retrofit kit. In this regard, reference is initially made to the patent claims subordinate to patent claim 1 and the patent claims subordinate to patent claim 14.In the following, a preferred embodiment of the retrofit kit according to the invention for an existing central heating system and of the method according to the invention for retrofitting an existing central heating system using a retrofit kit will be explained and described in more detail with reference to the drawing and the associated description. The drawing shows:

[0054] Fig.1a shows a schematic representation of a hydraulic circuit diagram of a first embodiment of the retrofit kit for an existing central heating system and the existing central heating system,

[0055] Fig.1b shows a schematic representation of a hydraulic circuit diagram of a second embodiment of the retrofit kit for an existing central heating system,

[0056] Fig.1c shows a schematic representation of a hydraulic circuit diagram of a third embodiment of the retrofit kit for another existing central heating system and this existing central heating system,

[0057] Fig.2 shows a simplified schematic diagram of the hydraulic circuit diagram of the first, second or third embodiment of the retrofit kit with the existing central heating system in the assembled state,

[0058] Fig.3a shows a schematic representation of a domestic hot water storage tank for use in

[0059] Central heating system in a side view,

[0060] Fig.3b shows a schematic representation of a domestic hot water storage tank for use in

[0061] Central heating system in a side view, with a changed temperature stratification in contrast to Fig.3a, Fig.4 in schematic representation a flow diagram for a method for operating and / or controlling and / or regulating a heat pump in the mounted state of the retrofit kit on the already existing central heating system according to Fig. 2,

[0062] Fig.5 shows a schematic diagram of a process for operating and / or controlling and / or regulating a primary heat source in the installed state of the retrofit kit on the existing central heating system according to Fig. 2,

[0063] 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

[0064] 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.

[0065] Fig.1a to Fig.1c each show a schematic representation of a hydraulic circuit diagram of a first to third embodiment of the retrofit kit 1 for an already existing central heating system 2. Fig.1a and Fig.1c also show the already existing central heating system 2.

[0066] The central heating system 2 comprises at least one fuel-operated primary heat source 3, in particular a boiler and / or a gas boiler, at least one heat exchanger 4, preferably a heater or a radiator for heating a building, and at least one domestic hot water storage tank 5. It should also be noted here that the terms "fuel-operated primary heat source 3" or "boiler" include, in particular, an oil-operated oil boiler or a gas-operated gas boiler.

[0067] A heat transfer fluid 6, in particular water, which can be conveyed through the pipe system shown here can be heated by means of the primary heat source 3. The heat transfer fluid 6, in particular previously heated, can be conveyed through the heat exchanger 4 by means of a heating pump 7. The heat transfer fluid 6 can be conveyed to the domestic water storage tank 5 by means of a storage pump 8 for heating domestic water 9 temporarily stored in the domestic water storage tank 5, in particular for heat transfer from the heat transfer fluid 6 to the domestic water 9 through or adjacent to the domestic water storage tank 5. The primary heat source 3 has a central heating control and / or regulating device 10 for its control and / or regulation.

[0068] The retrofit kit 1 and / or the existing central heating system 2 has at least one electrically operated heat pump 11, wherein the heat transfer fluid 6 can be heated by means of the heat pump 11. The essential components of a respective retrofit kit 1 are shown in Fig. 1a to Fig. 1c, each outlined by dot-dash lines. According to the first and second embodiments of the retrofit kit 1 from Fig. 1a and Fig. 1b, the heat pump 11 is part of the respective retrofit kit 1. According to the third embodiment of the retrofit kit 1 from Fig. 1c, the heat pump 11 is already part of the existing central heating system 2.

[0069] The heat transfer fluid 6 can be conveyed to the heat pump 11 or through the heat pump 3 for heating, in particular with the aid of a circulation pump 12. The heat transfer fluid 6 can be conveyed to or through the primary heat source 3 by means of the heating pump 7, in particular the circulation pump 12, and / or the storage pump 8.

[0070] Such a circulation pump 12 is also designed as part of the retrofit kit 1 according to Fig. 1a to Fig. 1c. On the other hand, it would also be conceivable, especially if the heat pump 11 is already part of the existing central heating system 2, that the circulation pump 12 is also part of the central heating system 2; however, the latter is not shown here.

[0071] The retrofit kit 1 has a temperature sensor 13.1 and a heat pump control and / or regulating device 14, wherein the temperature sensor 13.1 is or can be connected to the heat pump control and / or regulating device 14 for control, signal, and / or data purposes. The heat pump 11 is and / or can be connected to the heat pump control and / or regulating device 14 for control purposes. According to Fig. 1b, the heat pump 11 in the retrofit kit 1 is already connected to the heat pump control and / or regulating device 14 for control purposes. According to Figs. 1a and 1c, the heat pump 11 is initially not yet 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 11 can be controlled in response to a temperature sensor 13.1, the actual domestic hot water temperature TBI measured 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, can be controlled and / or regulated. In particular, this avoids the disadvantages described above and achieves corresponding advantages.

[0072] In the assembled state of the retrofit kit 1 with the already existing central heating system 2 shown in Fig.2 and in the schematic representation of the domestic hot water tank 5 for use in the central heating system 1 in Fig.3a and Fig.5b, the position of the temperature sensor 13.1 is shown or represented in the - 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.

[0073] The temperature sensor 13.1 could - in the mounted state - penetrate a wall of the domestic hot water tank 5 - viewed vertically - in the lower area of ​​the domestic hot water tank 50, so that a measuring area of ​​the temperature sensor 13.1 is then arranged or positioned within the domestic hot water tank 5 with direct contact to the domestic water 9 in the lower interior area of ​​the domestic hot water tank 5.

[0074] The temperature sensor 13.1 can be mounted according to Fig. 3a and Fig. 3b, in particular by means of a T-piece 15, in or on a part of a domestic water inflow line 18 formed between an inflow valve 16 and an inflow connection 17 of the domestic water storage tank 5. Also according to Fig. 3a and Fig. 5b, the measuring range of the temperature sensor 13.1—in the mounted state—is in direct contact with the domestic water 9, which is located in the lower area of ​​the domestic water storage tank 5. According to Fig. 3a and Fig. 3b, the T-piece 15 is interposed in the domestic water supply line 18 in such a way that a portion of the domestic water supply line 18 is connected to a branch of the T-piece 15, so that the temperature sensor 13.1 is also arranged at one of the two parallel connections of the T-piece 15 and closes this connection with a cap. The temperature sensor 13.1 preferably penetrates the T-piece 15 completely and, according to Fig. 3a and Fig. 5b, is arranged with its measuring range within the domestic hot water storage tank 5 despite being arranged on the T-piece 15. In contrast, it would also be conceivable for the measuring range of the temperature sensor 13.1 to be arranged within the domestic hot water supply line 18, in particular within the T-piece 15. In contrast, it would also be conceivable for the temperature sensor 13.1 - in the assembled state - is arranged on the outside of the wall of the domestic hot water storage tank 5, there then in the lower area of ​​the domestic hot water storage tank 5, or also on the outside of the domestic hot water inflow line 18, wherein when determining the actual domestic hot water temperature TBI by means of the heat pump control and / or regulating device 14, a temperature gradient occurring across the wall of the domestic hot water storage tank 5 or across a wall of the domestic hot water inflow line 18 is then taken into account when determining the actual domestic hot water temperature.

[0075] Fluidically adjacent to the inlet valve 16, a check valve 16.r is integrated and / or arranged in the domestic water inlet line 18 or interposed therein in order to prevent a backflow of the domestic water 9 from the domestic water storage tank 5 into the domestic water inlet line 18 even when the inlet valve 16 is open.

[0076] The temperature sensor 13.1 is designed here as a first temperature sensor 13.1 for determining a first actual domestic hot water temperature TBI. A second temperature sensor 13.2 is arranged in a—vertically viewed—middle or upper area of ​​the domestic hot water storage tank 5 for measuring a second, preferably average, actual domestic hot water temperature TB2. The second temperature sensor 13.2 is connected to the central heating control and / or regulation device 10 for control, signal, and / or data purposes.

[0077] The central heating control and / or regulation device 10 is designed and / or constructed such that the primary heat source 3 can be controlled and / or regulated as a function of the second actual domestic water temperature TB2.

[0078] The heat pump control and / or regulating device 14 is designed and / or configured such that the heat pump 11 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, in particular when the first actual domestic water temperature TBI measured, determined, and / or calculated, in particular 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 heat pump 11 and / or the circulating pump 12 are further controlled and / or regulated by the heat pump control and / or regulating device 14, in particular additionally depending on a first actual heat transfer fluid temperature Twi, formed at the outlet of the heat pump 11. In particular, a first target heat transfer fluid temperature Twi,son is set for the heat pump 11, which should then be present at the outlet of the heat pump 11.If the first actual heat transfer fluid temperature Twi falls below or exceeds the desired or determined and / or set first target heat transfer fluid temperature Twi.soii, the heat pump 11 is controlled and / or regulated accordingly, so that the first actual heat transfer fluid temperature Twi then again approaches the target heat transfer fluid temperature Twi,son, in particular when the first actual heat transfer fluid temperature Twi then again corresponds to the first target heat transfer fluid temperature Twi,son, at the start of the heat pump 11. In particular, the heat pump 11 is therefore also controlled and / or regulated depending on a set and / or desired specific first target heat transfer fluid temperature Twi,son. In particular, the desired and / or determined target heat transfer fluid temperature Twi,son is determined depending on a particularly determined outside temperature T. aand / or a desired room temperature of a room to be heated with the heat exchanger 4 is set and / or calculated, which will be explained again below.

[0079] The central heating control and / or regulating device 10 is designed and / or constructed such that the primary heat source 3 can be operated and / or activated with the aid of the central heating control and / or regulating device 10 to heat the heat transfer fluid 6 when the second actual domestic water temperature T measured, determined and / or calculated with the aid of the second temperature sensor 13.2 B 2 a second limit temperature T B 2G. The primary heat source 3 is further controlled by the central heating control and / or regulation device 10 depending on a second actual heat transfer fluid temperature T, which develops within or in the area of ​​the primary heat source 3. W2 is controlled and / or regulated. In particular, the primary source 3 is additionally controlled depending on a desired and / or set second target heat transfer fluid temperature T W 2,son is controlled and / or regulated. In particular, with the aid of the central heating control and / or regulation device 10, a desired and / or specific second target heat transfer fluid temperature TW2,son is set for the area of ​​the primary source 3 and / or for its distribution system, wherein when the second actual heat transfer fluid temperature T W 2 below the desired and / or set second target heat transfer fluid temperature T W 2, SOII falls, then the primary heat source 3 is actively operated to reheat the heat transfer fluid 6 accordingly, in particular until the second actual heat transfer fluid temperature T W 2 then the desired second target heat transfer fluid temperature T W 2, SOII. The first and second limit temperatures TBIG, TB 2G are now selected in particular such that the primary heat source 3 can be operated and / or activated with the aid of the central heating control and / or regulating device 10 to heat the heat transfer fluid 6 only when a heat demand of the domestic hot water storage tank 5 exceeds a heat quantity that can be provided by the heat pump 11 at maximum output of the heat pump 11. Simply put, the heat pump 11 will, in particular, operate with priority for as long as possible, i.e., it will operate with priority over the primary heat source 3.

[0080] For example, the first limit temperature TBIG is smaller than the second limit temperature T B2 G-

[0081] On the other hand, the second limit temperature T B2 G less than the first limit temperature T B I G , where the second limit temperature T B2Gin particular 43°C, in particular in the range from 41°C to 45°C, in which case the first limit temperature T B I G in particular 48°C and in particular in the range from 46°C to 50°C.

[0082] The two temperature sensors are referred to as the first and second temperature sensors for the sake of clarity. The designation "first" and "second" respectively therefore does not represent a relationship between them and is not to be considered restrictive. Another unambiguous designation for the two temperature sensors would be conceivable.

[0083] The processes for operating and / or controlling and / or regulating the heat pump 11 with the aid of the retrofit kit 1 according to Fig.2 mounted on the central heating system 2 are illustrated in more detail using a schematic representation of a flow diagram according to Fig.4.

[0084] First, it is continuously checked whether the first actual domestic water temperature TBI is below the first limit temperature T B I G If this is the case, the process step VWPI, namely the corresponding operation / control and / or activation of the heat pump 11, is carried out. The heat pump 11 is then operated in particular until the first actual domestic hot water temperature TBI is again above the first limit temperature T B I G It is also conceivable that a first switch-off limit temperature T B -I G ' is provided, which is preferably 4°C to 6°C above the first limit temperature T B I G and the heat pump 11 is then operated in particular until the first actual domestic water temperature TBI is above the first switch-off limit temperature T B I G'. If the first actual domestic hot water temperature TBI therefore exceeds the first limit temperature TBIG or the first switch-off limit temperature TBIG', process step VWP2 is carried out, namely a different operating mode and / or even the deactivation of the heat pump 11. The process then begins again by checking whether the first actual domestic hot water temperature TBI is below the first limit temperature TBIG. The process steps described above are carried out in particular when domestic hot water is withdrawn from the domestic hot water storage tank, e.g. for a shower, and new, "colder" domestic water is then fed back into the domestic hot water. The third heating circuit, in particular the storage pump 8, is activated at the same time to heat the domestic hot water.

[0085] The processes for operating and / or controlling and / or regulating the primary heat source 3 with the aid of the retrofit kit 1 mounted on the central heating system 2 according to Fig.2 are further illustrated by a schematic representation of a flow diagram according to Fig.5.

[0086] Here, it is first continuously checked whether the second actual domestic water temperature T B 2 below the second limit temperature T B2 G'. If this is the case, the process step VPRI , namely the operation and / or activation of the primary heat source 3, is carried out. The primary heat source 3 is then operated in particular until the second actual domestic water temperature T B2 again above the second limit temperature T B2 G. It is also conceivable that a second switch-off limit temperature T B2 G' is provided, which is preferably 4°C to 6°C above the second limit temperature TB2 G and the primary heat source 3 is then operated in particular until the second actual domestic water temperature T B2 above the second switch-off limit temperature T B2 G'. If the second actual domestic water temperature T B2 i.e. the second limit temperature T B2 G or the second switch-off limit temperature T B2G ', the process step VPR2 is carried out, namely a different operating mode and / or the deactivation of the primary heat source 3. The process then starts again with the check whether the second actual domestic water temperature T B2 below the second limit temperature T B2G. The process steps described above are carried out in particular when domestic water is withdrawn from the domestic water storage tank 5, e.g. for a shower, and new, "colder" domestic water is then fed back into the domestic water storage tank 5. The third heating circuit, in particular the storage pump 8, is activated at the same time to heat the domestic water or has already been activated, since the process steps described in Fig. 4 take place in particular before the process steps described in Fig. 5. Simply put, the correspondingly implemented control ensures that the heat pump 11 is controlled or used preferentially before the primary heat source 3 for heating the domestic water 9.

[0087] But even in a "normal heating operation" of the central heating system 2, i.e. when the domestic water 9 does not need to be heated and, for example, only the heat transfer fluid 6 needs to be heated to operate the heat exchanger 4, the heat pump 11 in particular can and will always be used preferentially before the primary heat source 3 to heat the heat transfer fluid 6 or activated and / or controlled accordingly; this should also be pointed out again.

[0088] In the very preferred embodiment of the retrofitted central heating system 2, it is now ensured in particular that the primary heat source 3 is operated and / or activated with the aid of the central heating control and / or regulating device 10 for heating the heat transfer fluid 6 only when a heat requirement of the heat exchanger 4 and / or the domestic hot water storage tank 5 exceeds a heat quantity that can be provided by the heat pump 11 at maximum output of the heat pump 11. Such a heat requirement of the heat exchanger 4 is also dependent in particular on a desired room temperature of a room to be heated by the heat exchanger 4. 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 14 for controlling and / or regulating the heat pump 11.One could also say that the first target heat transfer fluid temperature Twi, son, is then dependent on the desired room temperature. If the heat pump 11 is controlled and / or regulated based on the desired room temperature, this is also referred to as modulating operation of the heat pump 11.

[0089] During operation of the domestic hot water storage tank 5, a vertical temperature stratification of the domestic hot water 9 occurs in the domestic hot water storage tank 5. The first actual domestic hot water temperature TBI is measured – viewed vertically – in a lower, first temperature layer. The second actual domestic hot water temperature T B2 is measured - viewed vertically - in a middle or upper, second temperature layer. The first temperature layer forms vertically below the second temperature layer. This temperature stratification is shown in Figs. 1 a, 1c and 2 and in Fig. 3a with exemplary temperatures between 30°C in the first, lowest temperature layer and 45°C in the uppermost temperature layer. This temperature stratification shown in Fig. 3a between 30°C in the first, lowest temperature layer and 45°C in the uppermost temperature layer occurs in particular when the first limit temperature TBIG is lower than the second limit temperature T B 2G and then especially T B I G = 30° C and T B2 G < 40° C, especially T B2 G is selected between 35°C and 38°C.

[0090] If the second limit temperature T B2G less than the first limit temperature T B I Gis, in particular the second limit temperature T B2G in particular 43°C, in particular in the range from 41°C to 45°C, and the first limit temperature T B I G in particular 48°C and in particular in the range from 46°C to 50°C, then in particular a temperature stratification shown in Fig.3b between 50° in the first, lowest temperature layer and 60°C in the uppermost temperature layer occurs.

[0091] The temperatures shown in Figs. 3a and 3b in the individual layers there are in particular an average temperature for the respective layer.

[0092] The first actual domestic water temperature TBI therefore has lower values ​​than the second actual domestic water temperature T B2, when the domestic water 11 is at rest in the domestic water storage tank 5 for a certain period of time. The temperature stratification can change when domestic water 9 is withdrawn from the domestic water storage tank 5, in particular in its upper area, and / or "new" domestic water 9 is then fed back into the domestic water storage tank 5, in particular in its lower area, whereby a corresponding respective temperature stratification can generally be maintained by means of a corresponding discharge and supply concept within the domestic water storage tank 5.

[0093] Due to the fact that a temperature stratification, which can be seen and seen in Fig. 1 a, 1c, 2 3a and 3b, is formed in the domestic hot water storage tank 5, it is essentially ensured that the first actual domestic hot water temperature TBI is below the second actual domestic hot water temperature T B2The domestic hot water 9, in particular as shown in Figs. 2, 3a and 3b, can be fed to the domestic hot water storage tank 5 in the area of ​​the first, lower temperature sensor 13.1. If, in comparison to the domestic hot water 9 present in the domestic hot water storage tank 5, fresh, cold domestic hot water 9 is now fed 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 hot water temperature T B2 will only decrease later, especially when the fresh, cold domestic water 9 or its temperature has spread to the second temperature sensor 13.2.

[0094] The first limit temperature TBIG is set for a supply of cold domestic water 9 with appropriate selection of the values ​​of the limit temperatures TBIG, T B 2G to each other must always be undercut by the corresponding first actual domestic water temperature TBI before the second limit temperature T B2G by the second actual domestic water temperature T B2 will be undershot, so that the heat pump 11 is always operated / controlled and / or activated before the primary heat source 3. If the output of the heat pump 11 is then sufficient to cover the heat demand of the domestic hot water storage tank 5, the second actual domestic hot water temperature T B 2 not below the second limit temperature T B2 G and the primary heat source 3 does not need to be activated and then 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 and the primary heat source 3 is activated neither too early nor too late in order to save fuel and ensure a comfortable temperature for the domestic water 9 taken from the domestic water storage tank 5.

[0095] The first limit temperature TBIG is either below the second limit temperature T B2G as shown in Fig.6a or the first limit temperature TBIG is above the second limit temperature T B2G as shown in Fig.6b, where in the case that T B IG <T B2G is, in particular then the temperature stratification according to Fig.3a is established and in the case that TBIG>T B2 G or T B2G <T B IG, in particular the temperature stratification according to Fig.5b is established. In the above-mentioned first case, the first limit temperature TBIG is in particular set to 30° C and the second limit temperature T B2G < 40° C, especially T B2G between 35°C and 38°C. In the second case mentioned above, the first limit temperature TBIG is set in the range of 46°C to 50°C, in particular to 48°C, and the second limit temperature T B2G in the range of 41 ° C to 45 ° C, in particular set to 43 ° C, as previously described and / or explained. In this case, the second limit temperature T B2G then in particular 3°C to 7°C, in particular 5°C lower than the first limit temperature T BIG-

[0096] To set / initiate a particularly optimal temperature control and / or temperature regulation for heating the domestic hot water 9 of the domestic hot water storage tank 5, the following steps are initially carried out: In particular, after installation of the system and / or before operation of the system, the domestic hot water storage tank 5, which is initially completely filled with “cold” domestic hot water 9, is initially heated “only” by means of the primary heat source 3, or the domestic hot water 9 is heated here only with the aid of the heat transfer fluid 6 heated by the primary heat source 3. The heat pump 11 remains switched off during this phase. Only after the desired second actual domestic hot water temperature TB2 has been reached, i.e. only when the desired second actual domestic hot water temperature TB2 is determined by the second temperature filler 13.2, is the heat pump 11 switched on or connected.At the time when the desired hot water temperature of the domestic water 9 or the desired second actual domestic water temperature TB2 has been reached or determined at the second temperature filler 13.2, the current first actual domestic water temperature TBI present at the first temperature filler 13.1 is measured. To control the heat pump 11 for the further operation of the system, the first target heat transfer fluid temperature Twi, for controlling and / or regulating the heat pump 11, is then set to a value that is essentially 5°C higher than the above-mentioned and determined first actual domestic water temperature value TBI . The second target heat transfer fluid temperature T. W2, is set in particular to a value 7°C to 9°C, preferably 8°C lower than Twi, such a setting of the system prevents unnecessary operation of the primary heat source 3, wherein in particular the heat pump 11, as already described above, is sufficient to heat the domestic hot water 9 present in the domestic hot water storage tank 5 accordingly, without the need for operation of the primary heat source 3. The first and / or second limit temperature TBIG or T B 2G is then in particular 2° C to 5° C lower than the respective corresponding determined or desired first and second actual domestic water temperature TBI or T B 2 or is then automatically calculated accordingly by the heat pump control and / or regulating device 14.

[0097] In particular with reference to Fig. 3b, the following may now be stated again: It is now also conceivable that the second limit temperature T B 2G is set lower than the first limit temperature TBIG- For example, TBIG is set to 49° C and T B2G is set to 43°C. In particular, this essentially results in a temperature stratification as shown in Fig. 3b. The domestic hot water storage tank 5 in particular reaches an outlet temperature of 60°C in the uppermost layer, whereby protection against bacteria and legionella is initially realized or provided. Furthermore, the stratification shown in Fig. 3b also significantly increases the usable heated water quantity of the domestic hot water 9 in the domestic hot water storage tank 5 (compared to Fig. 3a), in particular since the domestic hot water 9 of the domestic hot water storage tank 5 is now essentially heated down to the lowest layer or the domestic hot water 9 located here is or is being heated accordingly. However, since the usable heated water quantity is now, for example, higher in Fig.3b is then increased, the heat pump 11 can be operated with a specific blocking time, even if the first actual domestic hot water temperature TBI falls below the first limit temperature TBIG. Or, to put it another way, only after a specific blocking time has elapsed is the domestic hot water 9 of the domestic hot water storage tank 5 heated again by the then active heat pump 11. This reduces the required timing of the heat pump 11; in particular, a setting of T contributes to this. B 2G < TBIG also ensures that the primary heat source 3 only contributes to heating the domestic hot water 9 in the domestic hot water storage tank 5 when the second actual domestic hot water temperature TB2 exceeds the second limit temperature T B2G, which is particularly the case when a correspondingly large amount of already heated domestic water 9 has been or is being drawn from the domestic water storage tank 5, for example, due to a large number of simultaneous showers in an apartment building. A specific off-time for the heat pump 11 can be considered as a shut-off time of 15 to 30 minutes.

[0098] The heating pump 7 is, in particular, dependent 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 regulating device 14. The heating pump 7 is, in particular, initially operated and / or activated synchronously with the heat pump 11 when the storage pump 8 is switched off, in particular deactivated. The synchronous control is made possible in particular by the fact that both the heating pump 7 and the heat pump 11 are controlled and / or regulated by means of the heat pump control and / or regulating device 14.

[0099] The heating pump 7 is switched off, in particular deactivated, by means of the heat pump control and / or regulating device 14 when the storage pump 8 is operated and / or activated by means of the heat pump control and / or regulating device 14, in particular due to the withdrawal of domestic water 9 from the domestic water storage tank 5. Thus, the domestic water 9 can be reheated more quickly with the aid of the heat transfer fluid 6 after domestic water 9 has been withdrawn from the domestic water storage tank 5 and after and / or during the supply of fresh, cold domestic water 9. Alternatively, the heating pump 7 and the storage pump 8 could also be operated simultaneously; however, in order to heat the domestic water 9 in the domestic water storage tank 5 in the same time, a correspondingly high output would then have to be provided by the heat pump 11 and / or the primary heat source 3.The simultaneous operation of the heating pump 7 and the storage pump 8 is also referred to as "parallel" operation of the central heating system 2. "Parallel" operation then enables the simultaneous heating of the building and the domestic water 9.

[0100] The heat exchanger 4 and the heat pump 11 are connected or switchable in series with respect to the primary heat source 3 in terms of flow technology, in particular in series according to Fig.2 and / or connected or switchable in series according to Fig.1a to Fig.1c.

[0101] Thus, the heat transfer fluid 6 preheated by means of the heat pump 11 can then be completely supplied to the primary heat source 3 when the retrofit kit 1 is mounted on the central heating system 2.

[0102] A heat exchanger inlet line LWT, ZUis fluidically connectable or connected and / or connected accordingly to the primary heat source 3 on the one hand and to the heat exchanger 4 on the other hand in order to convey the heat transfer fluid 6 by means of the heating pump 7 through the heat exchanger inflow line LWT, ZU to the heat exchanger 4, in particular wherein the heat exchanger inflow line LWT, ZU partly already present and partly part of the retrofit kit 1 , in particular part of the hydraulic module 21. A heat pump inlet line L W p, zu is fluidically connectable or connected and / or connected accordingly to the heat exchanger 4 on the one hand and to the heat pump 11 on the other hand in order to convey the heat transfer fluid 6 through the heat pump inlet line LWP, ZU to the heat pump 11, in particular wherein the heat pump inlet line LWP, zupartly already present and partly part of the retrofit kit 1, in particular part of the hydraulic module 21. A heat pump drain line LWP, ab is fluidically connected on the one hand to the heat pump 11 and on the other hand to the primary heat source 3 or can be connected and / or connected accordingly in order to supply the heat transfer fluid 6 through the heat pump drain line LWP, ab to the primary heat source 3, in particular wherein the heat pump drain line LWP, ab is partly already present and partly part of the retrofit kit 1, in particular part of the hydraulic module 21.

[0103] In simple terms, the retrofit kit 1 comprises at least corresponding pipes and / or hoses by means of which the desired fluidic connections between the components of the retrofit kit 1 and the existing central heating system 2 can be created or implemented. In particular, the retrofit kit 1 comprises the aforementioned hydraulic module 21 for this purpose.

[0104] In the primary heat source 3, a distribution system (shown in dashed lines in Fig. 1 a, 1c and 2) for the heat transfer fluid 6, i.e., corresponding flow channels through which the heat transfer fluid 6 can flow, is preferably provided, to which the heating circuits are connected. The heat exchanger inlet line L W p, zuand the heat pump drain line LWP, as well as a line leading to the domestic hot water tank 5 and a line returning from the domestic hot water tank 5, which each conduct or transport the heat transfer fluid 6, are connected to the primary heat source 3, in particular to such a distribution system, or are fluidly connected to the primary heat source 3, in particular a boiler. The heat transfer fluid 6 can therefore flow through the primary heat source 3, in particular the distribution system, so that the heat transfer fluid 6 is heated during this flow, if necessary also with the help of the primary heat source 3. However, the heat transfer fluid 6 can also flow through the primary heat source 3, in particular the distribution system, without the heat transfer fluid 6 being heated by the primary heat source 3 during this flow, in particular without the primary heat source 3 being actively operated.

[0105] The retrofit kit 1 has at least one valve 19, by means of which the heat transfer fluid 6 can be directed and / or guided either from the primary heat source 3 to the heat exchanger 4 or past the heat exchanger 4 to the heat pump 11.

[0106] The valve 19 is shown in Fig.1 a to Fig.2 as a single valve 19 with dashed lines, since it can be used as an alternative to the combination of two 3 / 2-way valves 20.1, 20.2 also described below.

[0107] As an alternative to the single valve 19, the retrofit kit 1 has two 3 / 2-way valves, each with three connections and two switching positions, namely a first one, in particular in the heat exchanger inlet line LWT, ZU arrangable or correspondingly arranged and / or interposed, 3 / 2-way valve 20.1 and a second, in particular in the heat pump inlet line L W p, zuarrangable or correspondingly arranged and / or interposed, 3 / 2-way valve 20.2. The first 3 / 2-way valve 20.1 is fluidically connectable or connected and / or correspondingly connectable or connected to the primary heat source 3 and to the heat exchanger 4 and to the second 3 / 2-way valve 20.2. The second 3 / 2-way valve is fluidically connectable or connected and / or correspondingly connectable or connected to the heat exchanger 4, to the heat pump, and to the first 3 / 2-way valve 20.1. By means of the first 3 / 2-way valve

[0108] 20.1, when connected, enables the heat transfer fluid 6 to flow either from the primary heat source 3 to the heat exchanger 4 or to the second 3 / 2-way valve 20.2. The second 3 / 2-way valve 20.1, when connected, enables the heat transfer fluid 6 to flow either from the heat exchanger 4 or from the first 3 / 2-way valve 20.1 to the heat pump 11.

[0109] These described flow paths, which can be implemented by means of the two 3 / 2-way valves 20.1, 20.2, can also be implemented by means of the one, single valve 19, wherein this one valve 19 is then designed in particular as a 4 / 2-way valve with four connections and two switching positions, wherein in the first switching position of the valve 19 with the retrofit kit installed - i.e. in the connected state - a flow of the heat transfer fluid 6 from the primary heat source 3 via the heat exchanger 4 to the heat pump 11 is enabled, and wherein in a second switching position of the valve 19 with the retrofit kit installed, a flow of the heat transfer fluid 6 from the primary heat source 3 past the heat exchanger 4 to the heat pump 11 is enabled.

[0110] The previously mentioned valve 19, in particular the first and second 3 / 2-way valves 20.1 and 20.2 respectively.

[0111] 20.2 or a valve 19, which is designed as a 4 / 2-way valve, as mentioned above, is also connected, in particular in terms of control technology, to the heat pump control and / or regulating device 14, which is intended to be illustrated by a corresponding dashed line, particularly in Fig. 2. Or, to put it another way, the respective switching positions of the aforementioned valve 19 can be realized with the aid of the heat pump control and / or regulating device 14.

[0112] From the group of elements / components, namely the heat exchanger inlet line L W T, ZU at least in sections, the heat pump inlet line L W p, zu at least in sections, the heat pump drain line L Wp,ab at least in sections, of the circulation pump 12, the heat pump control and / or regulating device 14 and the valve 19, in particular the first 3 / 2-way valve 20.1 and the second 3 / 2-way valve 20.2, are at least two elements and / or components, in particular the heat exchanger inflow line LWT, ZU in sections, the heat pump inlet line L W p, zu in sections, the heat pump discharge line LWP, from in sections, the first 3 / 2-way valve 20.1 and the second 3 / 2-way valve 20.2, but preferably all elements and / or components, and respectively associated connections are arranged and / or formed on a hydraulic module 21 forming a common structural unit.

[0113] According to Fig. 1 a and Fig. 1 c, the heat pump control and / or regulating device 14 is not connected to the hydraulic module 21. According to Fig. 1 b, the heat pump control and / or regulating device 14 is connected to the hydraulic module 21 or integrated therein. For the sake of clarity, the heat pump control and / or regulating device 14 is shown in Fig. 2 next to the hydraulic module 21. However, Fig. 2 shows the assembled state for all three exemplary embodiments according to Fig. 1 a to Fig. 1 c, so that according to Fig. 2, the heat pump control and / or regulating device 14 could also be connected to the hydraulic module 21; this should be noted.

[0114] The central heating system 2 is typically arranged inside a building. The heat pump 11, in particular an air-to-water heat pump 11 designed as a compact structural unit, can be arranged both inside a building and outside the building. When arranged inside the building, the heat pump 11, after its installation, is connected to the outside environment of the building via air vents. The hydraulic module 21 is preferably designed to be mounted adjacent to the central heating system 2 inside the building, so that the flow paths to be implemented can be particularly short, and the components / elements connected to the hydraulic module 21 can be protected from the effects of the weather by the building.

[0115] The hydraulic module 21 has, in particular, a frame 22 for connecting the hydraulic module 21 to a building wall and / or to the primary heat source 3. The frame 22 could, for example, be designed as a welded construction. However, the frame 22 could also be arranged or mounted on a floor of the building.

[0116] The part of the heat exchanger inlet line LWT belonging to retrofit kit 1, ZU has a first connection 23.1 for supplying the heat transfer fluid 6 to the hydraulic module 21 and a second connection 23.2 for discharging the heat transfer fluid 6 from the hydraulic module 21. The part of the heat pump inflow line L belonging to the retrofit kit 1 W p, zuhas a third connection 23.3 for supplying the heat transfer fluid 6 to the hydraulic module 21 and a fourth connection 23.4 for discharging the heat transfer fluid 6 from the hydraulic module 21. The part of the heat pump drain line Lwp.ab associated with the retrofit kit 1 has a fifth connection 23.5 for supplying the heat transfer fluid 6 to the hydraulic module 21 and a sixth connection 23.6 for discharging the heat transfer fluid 6 from the hydraulic module 21.

[0117] The connections 23.1 to 23.6 are spatially arranged on the hydraulic module 21 or formed in the hydraulic module 21 in such a way that a particularly simple and rapid connection to the parts of the corresponding lines belonging to the central heating system 2 is possible. Furthermore, the spatial arrangement of the connections 23.1 to 23.6 and the lines is optimized accordingly, in particular with regard to the short flow paths to be realized, designed with low flow resistance.

[0118] In the following, a method for retrofitting an existing central heating system 2 using the retrofit kit 1 described above will be described in more detail:

[0119] The retrofitting procedure is carried out in order to get from the separated state of retrofit kit 1 and central heating system 2 shown in Fig.1a to Fig.1c to the assembled state of retrofit kit 1 and central heating system 2 shown in Fig.2.

[0120] The - first - temperature sensor 13.1 is mounted and / or 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.

[0121] The first temperature sensor 13.1 is mounted either with direct contact of the measuring range of the first temperature sensor 13.1 to the brewing water 9 or in or on a wall of the domestic hot water tank 5 or the domestic hot water inflow line 18 - viewed vertically - at the lower area of ​​the domestic hot water tank 5.

[0122] The first temperature sensor 13.1 is connected to the heat pump control and / or regulating device 14 for control, signal, and / or data purposes. In particular, a cable from the first temperature sensor 13.1 is connected to the heat pump and / or regulating device 14 for control, signal, and / or data purposes using a plug connection. Alternatively, a wireless connection, e.g., by radio, in particular Bluetooth, would also be conceivable and would then be set up accordingly. If the heat pump 11 is part of the existing central heating system 2, the heat pump 11 is connected to the heat pump control and / or regulating device 14 for control purposes. Or, if the heat pump 11 is part of the retrofit kit 1, the heat pump 11 is connected to the heat pump control and / or regulating device 14 for control purposes or is already connected.

[0123] The storage pump 8 is connected to the heat pump control and / or regulation device 14 for control purposes.

[0124] The heating pump 7 is connected to the heat pump control and / or regulation device 14 for control purposes.

[0125] If the valve 19 is provided, the valve 19 is connected to the heat pump control and / or regulating device 14 for control purposes.

[0126] As an alternative to the valve 19, the first 3 / 2-way valve 20.1 and the second 3 / 2-way valve 20.2 are each connected to the heat pump control and / or regulating device 14 for control purposes.

[0127] All of these control connections are created using a cable and / or wirelessly, in particular by radio.

[0128] An outside temperature sensor 13.a is mounted in an outside area, wherein the outside temperature sensor 13.a is or will be connected to the heat pump control and / or regulation device 14 in terms of control, signal and / or data technology.

[0129] The outside temperature sensor 13.a is in particular adapted to the heat pump control and / or regulation device 14, so that a correct determination of the outside temperature in the external environment of a building is then possible.

[0130] The first limit temperature TBIG or a table and / or a formula for determining the first limit temperature TBIG is entered into the heat pump control and / or regulation device 14 and / or is already stored there. The second limit temperature T B 2G or a table and / or a formula for determining the second limit temperature T B2G is entered into the central heating control and / or regulation device 10 and / or is already stored there. When using the formula, it is particularly conceivable that certain parameters for this formula are also entered.

[0131] The limit temperature TBIG or the table and / or the formula for determining the first limit temperature TBIG is entered, for example, on a control panel of the heat pump control and / or regulating device 14. Alternatively, it would be conceivable to couple an input unit, preferably a computer, to the heat pump control and / or regulating device 14 and to make the input using this input unit. This also applies analogously to the second limit temperature T B2G and the central heating control and / or regulating device 10. In the highly preferred embodiment, however, the heat pump and / or regulating device 14 is designed as a computer and / or has a corresponding microprocessor for implementing the respective calculations and / or desired control sequences. Analogously, the central heating control and / or regulating device 10 can also be designed as a computer or have a microprocessor.

[0132] It is conceivable that a further outside temperature sensor is connected to the central heating control and / or regulation device 10 for control / signal / and / or data purposes, so that the outside temperature T a can also be determined by means of this additional outside temperature sensor and the central heating control and / or regulation device 10.

[0133] Fig.6a and 6b show a schematic representation of the first limit temperature TBIG and the second limit temperature TB2 G with reference to the outside temperature T a , as these are entered or stored, for example, in tabular form or as a formula in the heat pump control and / or regulation device 14 or the central heating control and / or regulation device 10. In particular, Figs. 6a and 6b also show the settings of the first and second target heat transfer fluid temperatures Twi, son and T W 2, depending on a corresponding outside temperature T a .

[0134] The first and second limit temperatures TBIG, T B2 G 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 B2Gare 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 10, so that the first and second limit temperatures TBIG, T B2G for the sake of simplicity, independent of the outside temperature T a Regarding the setting / initiation of the target heat transfer fluid temperature Twi, son or T W 2,son and the respective first and second limit temperatures TBIG and T B 2G, reference may be made to the above statements. However, it may be added at this point that a temperature difference between the first target heat transfer fluid temperature Twi. soii and the second target heat transfer fluid temperature T W 2, preferably 7° C to 9° C, especially 8° C with T W2,son < Twi,son. In other words, the second target heat transfer fluid temperature Tw2,son is set at a value 7°C to 9°C lower than the first target heat transfer fluid temperature Twi,son. The second limit temperature T B2 G is in particular smaller than the second target heat transfer fluid temperature TW2, SOII, preferably at least 2° C to 5° C smaller, preferably 3° C to 4° C smaller. Thus, in particular, effective heating of the domestic water 9 can also be achieved by means of the primary heat source 3.

[0135] The part of the heat exchanger inlet line L belonging to retrofit kit 1 W T, zu is connected to the already existing part of the heat exchanger inlet line L by means of the first and second connection 23.1 , 23.2 W T, ZU connected. The part of the heat pump inlet line LWP belonging to retrofit kit 1, zuis connected to the existing part of the heat pump inlet line LWP by means of the third and fourth connection 23.3, 23.4, ZU The section of the heat pump drain line LWP, ab belonging to retrofit kit 1 is connected to the existing section of the heat pump drain line LWP, ab using the fifth and sixth connections 23.5, 23.6. This can be easily accomplished using the appropriately designed hydraulic module 21.

[0136] Finally, it should be pointed out again that the central heating control and / or regulating device 10 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. In particular, the central heating control and / or regulating device 10 and the heat pump control and / or regulating device 14 are preferably designed separately from one another so that they do not directly influence one another and the controls and / or regulations carried out by means of the central heating control and / or regulating device 10 and those carried out by means of the heat pump control and / or regulating device 14 are independent of one another. In this case, the control and / or regulation of the heat pump 11 and the primary heat source 3 takes place independently of one another.However, this means in particular that no parameters and / or measured values ​​for the control of the primary heat source 3, such as a level of fuel supply, are then available in the heat pump control and / or regulating device 14. On the other hand, in particular no operating data and / or parameters of the heat pump 11 are available in the central heating control and / or regulating device 10. The control of the primary heat source 3 takes place, in particular exclusively with the aid of the central heating control and / or regulating device 10, wherein the control of the heat pump 11 takes place, in particular exclusively with the aid of the heat pump control and / or regulating device 14. A particularly indirect dependency between the control and / or regulating of the heat pump 11 and the primary heat source 3 arises, in particular, only through the selection of the two limit temperatures TBIG and T. B2G to each other and by the specific arrangement of the two temperature sensors 13.1, 13.2 to each other. This is particularly advantageous if the heat pump control and / or regulating device 14 including the heat pump 11 is integrated into an existing central heating system during retrofitting, since then the central heating control and / or regulating device 10 does not have to be modified. The heat pump control and / or regulating device 14 is connected in particular only to the central heating control and / or regulating device 10 for the purpose of supplying energy to the heat pump control and / or regulating device 14, which is also symbolized in particular by a dashed line, in particular in Fig. 2. A connection of the heat pump control and / or regulating device 14 to the power grid is also conceivable. As a result, simple and cost-effective control of the system can be achieved.The central heating control and / or regulating device 10 and the heat pump control and / or regulating device 14 can operate essentially independently of one another or can then control the central heating system 2, particularly retrofitted with the retrofit kit 1, essentially independently of one another. A system that initially has only one primary heat source 3, for example, can therefore be easily and cost-effectively retrofitted with a heat pump 11 and the heat pump control and / or regulating device 14. This should be emphasized again.

[0137] After connecting / using the retrofit kit 1, all desired fluidic and / or control connections are realized, and the correspondingly retrofitted central heating system 2 can then be easily controlled and / or operated, particularly as described above, with the previously explained advantages.

[0138] 1 Retrofit kit 2 Central heating system 3 Primary heat source 4 Heat exchanger 5 Domestic hot water storage tank 6 Heat transfer fluid 7 Heating pump 8 Storage pump 9 Domestic hot water 10 Central heating control and / or regulation device

[0139] 1 1 Heat pump 12 Circulation pump

[0140] 13.1 First temperature sensor 13.2 Second temperature sensor 13. a Outside temperature sensor 14 Heat pump control and / or regulation device 15 T-piece 16 Inlet valve 16. r Check valve 17 Inlet connection 18 Domestic hot water inlet line 19 Valve

[0141] 20.1 First 3 / 2-way valve 20.2 Second 3 / 2-way valve 21 Hydraulic module 22 Frame 23.1 First connection 23.2 Second connection 23.3 Third connection 23.4 Fourth connection 23.5 Fifth connection 23.6 Sixth connection

[0142] TBI first actual domestic water temperature TB2 second actual domestic water temperature

[0143] TBIG first limit temperature

[0144] TBI G' first switch-off limit temperature

[0145] TB2G second limit temperature

[0146] TB2G' second switch-off limit temperature

[0147] T a Outside temperature

[0148] Twi first actual heat transfer fluid temperature

[0149] TW2 second actual heat transfer fluid temperature

[0150] Twi.soii first target heat transfer fluid temperature

[0151] TW2, second target heat transfer fluid temperature

[0152] LWT, ZU heat exchanger inflow line

[0153] LWP, to heat pump inlet line

[0154] LWP, from heat pump drain line

[0155] VWPI Operating and / or activating the heat pump 3

[0156] V W P2 Deactivation of the heat pump 3

[0157] VPRI Operating and / or activating the primary heat source 2

[0158] VPR2 Deactivation of primary heat source 2

Claims

Patent claims 1. Retrofit kit (1) for an existing central heating system (2), wherein the central heating system (2) comprises at least one primary heat source (3) operable with the aid of fuels, in particular a boiler and / or a gas boiler, at least one heat exchanger (4), preferably a heating element or a radiator for heating a building, and at least one domestic hot water storage tank (5), wherein a heat transfer fluid (6), in particular water, can be heated by means of the primary heat source (3), wherein the heat transfer fluid (6), in particular previously heated, can be conveyed to and / or through the heat exchanger (4) by means of a heating pump (7), wherein the heat transfer fluid (6) can be conveyed to the domestic hot water storage tank (5) by means of a storage pump (8) for heating domestic hot water (9) temporarily stored in the domestic hot water storage tank (5), in particular for heat transfer from the heat transfer fluid (6) to the domestic hot water (9) through or adjacent to the domestic hot water storage tank (5),wherein the primary heat source (3) has a central heating control and / or regulating device (10) for controlling and / or regulating the same, wherein the retrofit kit (1) and / or the central heating system (2) has at least one electrically operated heat pump (11), wherein the heat transfer fluid (6) can be heated by means of the heat pump (11), wherein, in particular with the aid of a circulating pump (12), the heat transfer fluid (6) can be conveyed to and / or through the heat pump (11) for heating thereof, and wherein the heat transfer fluid (6) can be conveyed to and / or through the primary heat source (3) by means of the heating pump (7), in particular the circulating pump (12), and / or the storage pump (8), characterized in that the retrofit kit (1) has a temperature sensor (13.1) and a heat pump control and / or regulating device (14),wherein the temperature sensor (13.1) is connected or connectable to the heat pump control and / or regulating device (14) in terms of control, signaling, and / or data technology, wherein the heat pump (11) is connected and / or connectable to the heat pump control and / or regulating device (14) in terms of control, signaling, and / or data technology, wherein the heat pump control and / or regulating device (14) is designed and / or constructed such that the heat pump (11) is controllable and / or regulatable as a function of an actual domestic water temperature (TBI) measured by means of the temperature sensor (13.1) in a - viewed vertically - lower region of the domestic water storage tank (5) or adjacent to this - viewed vertically - lower region of the domestic water storage tank (5).

2. Retrofit kit (1) according to claim 1, characterized in that the temperature sensor (13.1) can be mounted by means of a T-piece (15), in particular in or on a part of a domestic water inflow line (18) formed between an inflow valve (16) and an inflow connection (17) of the domestic water storage tank (5).

3. Retrofit kit according to claim 1, characterized in that the temperature sensor (13.1) can be arranged on the wall of the domestic water storage tank (5) in the - vertically viewed - lower area of ​​the domestic water storage tank (5).

4. Retrofit kit (1) according to one of claims 1 to 3, 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 - vertically viewed - middle or upper region of the domestic water storage tank (5) for measuring and / or determining 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 (10) for control / signal / and / or data purposes, wherein the central heating control and / or regulating device (10) is designed and / or constructed such that the primary heat source (3) is controlled as a function of the second actual domestic water temperature (T B2) is controllable and / or regulatable, wherein the heat pump control and / or regulating device (14) is designed and / or constructed such that the heat pump (11) can be operated and / or activated with the aid of the heat pump control and / or regulating device (14) to heat the heat transfer fluid (6) when the first actual domestic water temperature (TBI) measured, determined and / or calculated, in particular 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).

5. Retrofit kit (1) according to one of claims 1 to 4, characterized in that the central heating control and / or regulating device (10) is designed and / or constructed such that the primary heat source (3) can be operated and / or activated with the aid of the central heating control and / or regulating device (10) to heat the heat transfer fluid (6) when the second actual domestic water temperature (T B 2) a second limit temperature (T B 2G).

6. Retrofit kit according to claim 5, characterized in that the first and second limit temperatures (TBIG, T B2G) are selected such that the primary heat source (3) can only be operated and / or activated with the aid of the central heating control and / or regulating device (10) for heating the heat transfer fluid (6) 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 (11) at maximum output of the heat pump (11).

7. Retrofit kit (1) according to one of the preceding claims, characterized in that the heat exchanger (4) and the heat pump (11) are fluidically connected in series with respect to the primary heat source (3) and / or can be connected in series.

8. Retrofit kit (1) according to one of the preceding claims, in particular according to claim 7, characterized in that a heat exchanger inflow line (LWT, ZU) is fluidically connectable or connected and / or correspondingly connected to the primary heat source (3) on the one hand and to the heat exchanger (4) on the other hand in order to supply the heat transfer fluid (6) to the heat exchanger (4) by means of the heating pump (7) through the heat exchanger inflow line (LWT, ZU), in particular wherein the heat exchanger inflow line (LWT, ZU) is partly already present and partly part of the retrofit kit (1), wherein a heat pump inflow line (L W p, to) on the one hand fluidically connectable to the heat exchanger (4) and on the other hand to the heat pump (11) or connected and / or connected accordingly in order to convey the heat transfer fluid (6) through the heat pump inflow line (L Wp, to) to the heat pump (11), in particular wherein the heat pump inflow line (L W p, to) is partly already present and partly part of the retrofit kit (1), whereby a heat pump drain line (L W p, ab) is fluidically connectable or connected and / or connected accordingly to the heat pump (11) on the one hand and to the primary heat source (3) on the other hand, in order to convey the heat transfer fluid (6) through the heat pump discharge line (L W p, ab) to the primary heat source (3), in particular wherein the heat pump discharge line (L W ,ab) is partly already present and partly part of the retrofit kit (1 ).

9. Retrofit kit (1) according to claim 8, characterized in that the retrofit kit (1) has at least one valve (19) by means of which the heat transfer fluid (6) can be directed and / or guided either from the primary heat source (3) to the heat exchanger (4) or past the heat exchanger (4) to the heat pump (11).

10. Retrofit kit (1) according to claim 8 or 9, characterized in that the retrofit kit (1) comprises two 3 / 2-way valves, each with three connections and two switching positions, namely a first one, in particular in the heat exchanger inlet line (L W T, ZU ) and / or arranged or interposed, 3 / 2-way valve (20.1 ) and a second, in particular in the heat pump inlet line (L Wp, to) and / or arranged or interposed, 3 / 2-way valve (20.2), wherein the first 3 / 2-way valve (20.1) is fluidically connectable or connected and / or correspondingly connected to the primary heat source (3), to the heat exchanger (4) and to the second 3 / 2-way valve (20.2), wherein the second 3 / 2-way valve is fluidically connectable or connected and / or correspondingly connected to the heat exchanger (4), to the heat pump (11) and to the first 3 / 2-way valve (20.1), wherein by means of the first 3 / 2-way valve (20.1) - in the connected state - optionally a flow of the heat transfer fluid (6) from the primary heat source (3) to the heat exchanger (4) or to the second 3 / 2-way valve (20.2) is enabled, and by means of the second 3 / 2-way valve (20.1 ) - when connected - optionally a flow of the heat transfer fluid (6) from the heat exchanger (4) or from the first 3 / 2-way valve (20.1 ) to the heat pump (11 ) is possible.

11. Retrofit kit (1) according to one of claims 8 to 10, characterized in that from the group of elements / components, namely the heat exchanger inflow line (L W T, ZU ) at least in sections, of the heat pump inlet line (L W p, to) at least in sections, of the heat pump discharge line (L W p, ab) at least in sections, the circulation pump (12), the heat pump control and / or regulating device (14) and the valve (19), in particular the first 3 / 2-way valve (20.1) and the second 3 / 2-way valve (20.2), at least two elements and / or components, but in particular the heat exchanger inflow line (L W T, ZU ) in sections, the heat pump inlet line (L W p, z U) in sections, the heat pump drain line (L W p, ab) in sections, the first 3 / 2-way valve (20.1) and the second 3 / 2-way valve (20.2), but preferably all elements and / or components, and respectively associated connections are arranged and / or formed on a hydraulic module (21) forming a common structural unit.

12. Retrofit kit (1) according to claim 11, characterized in that the hydraulic module (21) has a frame (22) for fastening and / or arranging the hydraulic module (21) with a building wall and / or the primary heat source (3).

13. Retrofit kit (1) according to claim 11 or 12, characterized in that the part of the heat exchanger inflow line (LWT, ZU) belonging to the retrofit kit (1) has a first connection (23.1) for supplying the heat transfer fluid (6) to the hydraulic module (21) and a second connection (23.2) for discharging the heat transfer fluid (6) from the hydraulic module (21), wherein the part of the heat pump inflow line (LWP, zu) belonging to the retrofit kit (1) has a third connection (23.3) for supplying the heat transfer fluid (6) to the hydraulic module (21) and a fourth connection (23.4) for discharging the heat transfer fluid (6) from the hydraulic module (21), wherein the part of the heat pump outflow line (LWP, ab) belonging to the retrofit kit (1) has a fifth connection (23.5) for supplying the Heat transfer fluid (6) to the hydraulic module (21) and a sixth connection (23.6) for discharging the heat transfer fluid (6) from the hydraulic module (21).

14. Method for retrofitting an existing central heating system (2) by means of a retrofit kit (1) according to one of the preceding claims, characterized in that the - first - temperature sensor (13.1) is mounted and / or 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).

15. Method according to claim 14, characterized in that the first temperature sensor (13.1) is connected to the heat pump control and / or regulating device (14) in terms of control, signal and / or data.

16. Method according to claim 14 or 15, characterized in that, in the event that the heat pump (11) is part of the already existing central heating system (2), the heat pump (11) is connected in terms of control technology (14) to the heat pump control and / or regulating device, or in the event that the heat pump (11) is part of the retrofit kit (1), the heat pump (11) is already connected or is connected in terms of control technology to the heat pump control and / or regulating device (14).

17. Method according to one of claims 14 to 16, characterized in that the storage pump (8) is connected to the heat pump control and / or regulating device (14) for control purposes.

18. Method according to one of claims 14 to 17, characterized in that the heating pump (7) is connected to the heat pump control and / or regulating device (14) for control purposes.

19. Method according to one of claims 14 to 18, characterized in that the valve (19) is connected to the heat pump control and / or regulating device (14) for control purposes.

20. Method according to one of claims 14 to 19, characterized in that the first 3 / 2-way valve (20.1) and the second 3 / 2-way valve (20.2) are each connected for control purposes to the heat pump control and / or regulating device (14).

21. Method according to one of claims 14 to 20, characterized in that an outside temperature sensor (13.a) is mounted in an outside area, wherein the outside temperature sensor (13.a) is or becomes connected to the heat pump control and / or regulating device (14) in terms of control, signal and / or data technology.

22. Method according to one of claims 14 to 21, characterized in that the first limit temperature (TBIG) or a table and / or a formula for determining the first limit temperature (TBIG) is input into the heat pump control and / or regulating device (14) and / or is already stored there, wherein the second limit temperature (TB2G) or a table and / or a formula for determining the second limit temperature (T B 2G) is entered into the central heating control and / or regulation device (10) and / or is already stored there.

23. Method according to one of claims 14 to 22, characterized in that the part of the heat exchanger inflow line (LWT, ZU) belonging to the retrofit kit (1) is connected to the already existing part of the heat exchanger inflow line (LWT, ZU) by means of the first and the second connection (23.1, 23.2), wherein the part of the heat pump inflow line (LW p, to) is connected to the already existing part of the heat pump inflow line (LwP, to) by means of the third and fourth connection (23.3, 23.4), wherein the part of the heat pump outflow line (L W p,at>) by means of the fifth and sixth connection (23.5, 23.6) to the already existing part of the heat pump drain line (L W p, ab), in particular wherein the hydraulic module 21 is connected to the existing central heating system 2 for its retrofitting.

24. Method according to one of claims 14 to 23, characterized in that the central heating control and / or regulating device (10) and the heat pump control and / or regulating device (14) operate independently of one another, in particular the first limit temperature (TBIG) is entered at / in the heat pump control and / or regulating device (14) or is already defined there and / or the input of the second limit temperature (T B 2G) is entered on / in the central heating control and / or regulation device (10) or is already defined there.

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