Heating system and heating device, in particular hybrid heating device

Abstract

A heating system (10a; 10b; 10c) is proposed, comprising a heating device (12a; 12b; 12c), in particular a hybrid heating device comprising at least two heating units (14a, 16a; 14b, 16b; 14c, 16c), and an alternative heating unit (18a; 18b; 18c), which is in particular designed as an electric heating block.

Description

State of the art

[0001] Hybrid heating systems comprising a heat pump and a gas heating block are already known. These are designed to provide heat energy for a household's central heating system and a household hot water system. The heat pump supplies energy up to a certain temperature, depending in particular on the refrigerant used in the heat pump, for example, up to a temperature of 55°C. If the heating system and the hot water system require a higher temperature and thus a greater amount of energy, the gas heating block is switched on. Disclosure of the invention

[0002] A heating system is proposed comprising a heating device, in particular a hybrid heating device, which has at least two heating units, and an alternative heating unit, which is designed in particular as an electric heating block. A "hybrid heating device" in this context refers to heating devices with at least two heating units based on two different energy conversion principles, such as, in particular, a principle in which a fuel, in particular a fossil fuel, is burned to generate thermal energy, and a principle in which electrical energy is converted into thermal energy. An "alternative heating unit" in this context refers to a heating unit that differs from at least one and preferably from both of the at least two heating units of the heating device, in particular in its energy conversion principle.Various configurations that would appear appropriate to those skilled in the art are conceivable. However, the alternative unit is particularly advantageously designed as an electric heating block, preferably with resistance heating elements, so that the heating system, in particular, can be operated entirely electrically. Furthermore, at least one heating unit of the heating device and / or the alternative heating unit can be designed as a hydrogen heating unit.

[0003] The alternative heating unit can already be at least partially pre-installed and thus be provided, in particular, as a replacement for at least one of the heating units of the hybrid heating unit. Alternatively, however, at least one of the two heating units of the heating device is preferably provided for replacement with the alternative heating unit, particularly preferably by an end customer. "Provided" in this context is understood to mean specially equipped, specially designed, and / or specially programmed. Plug connections are preferably provided, by means of which the alternative heating unit can be easily installed electrically and preferably also in terms of control technology, thus achieving a so-called plug-and-play solution. The heating unit to be replaced can be deactivated only or deactivated and removed.

[0004] Through appropriate design, a particularly high degree of flexibility can be achieved with regard to the use of fuel and electricity, as well as with regard to required energy demand and temperatures within the system, especially after installation. It is particularly advantageous to respond to changes such as lower energy demand due to newly installed thermal insulation, changes in availability (e.g., due to the installation of a PV system, hot water collectors), changes in the price of electricity, fuel, etc.

[0005] The heating device can comprise various heating units that a person skilled in the art deems appropriate. However, one heating unit is particularly advantageously designed as a fuel heating block, in particular a gas heating block, and / or at least as a heat pump. The heat pump can be designed for replacement. However, the fuel heating block is particularly advantageously designed for replacement, allowing for particularly flexible response to expected changes.

[0006] In a further embodiment, it is proposed that the heating system comprise a housing, wherein the at least two heating units of the heating device are each arranged at least partially within the housing, such as advantageously a burner of a heating unit designed as a fuel heating block and an in-house unit of a heating unit designed as a heat pump. Particularly advantageously, a hydraulic unit of the heating system, which is preferably designed at least partially in one piece with a hydraulic unit of the heating unit designed as a heat pump, is also arranged within the housing, such as advantageously a pump for circulating water within a household, valves such as pressure equalization valves, expansion tanks and / or degassing units, etc.

[0007] In principle, it is also conceivable for the person skilled in the art to arrange other sub-units of the at least two heating units within the housing that appear appropriate. An advantageously compact and cost-effective unit can be achieved, in particular if the alternative heating unit is also arranged within the housing, either after pre-installation, upon delivery, or at least after replacement, and is intended to be arranged within the housing. An installer can carry out the replacement with minimal effort, in particular CO2-free. During the replacement, a space that was previously occupied by the heating unit of the heating device to be replaced can advantageously be used, such as preferably the heating unit designed as a fuel heating block, or an area specifically provided for this purpose within the housing can be used, such as preferably an area adjacent to the fuel heating block.

[0008] It is further proposed that the heating system comprise a control and / or regulating unit designed to control and / or regulate the alternative heating unit, thereby saving components and costs. Particularly advantageously, the control and / or regulating unit is also arranged within the housing. A provided electronic unit advantageously remains unchanged.

[0009] Advantageously, a hydraulic unit of the heating system also remains unchanged when one of the heating units of the heating device is deactivated and the alternative heating unit is activated.

[0010] In addition, components and installation effort can be saved if the alternative unit is designed to process a signal from at least one of the heating units, particularly advantageously a signal for controlling a fan.

[0011] It is further proposed that the heating system comprise a primary circuit which comprises at least one internal heat exchanger, different from the heating units and / or the alternative heating unit, for heating domestic and / or drinking water. Preferably, the heating units or at least one of the heating units and the alternative heating unit are fluidically integrated in the primary circuit. The primary circuit is preferably provided for circulating a heat transfer medium, in particular heating water, in order to transfer heat from the heating units or one of the heating units and the alternative heating unit to consumers, such as space heating and / or hot water preparation. The internal heat exchanger is preferably provided for hot water preparation. The internal heat exchanger is preferably arranged in the housing of the heating device. The internal heat exchanger is preferably designed as a continuous-flow heater.Alternatively or in addition to the internal heat exchanger, the heating system can have a hot water tank, in particular outside the housing of the heating device, for storing hot water, which is fluidically integrated into a secondary circuit of the heating system. In a configuration with a hot water tank, the heating device has, for example, fluid connections for integrating an external heat exchanger of the hot water tank, in particular instead of the internal heat exchanger or fluidically connected in parallel to the internal heat exchanger. The configuration according to the invention makes it possible to provide an advantageously space-saving heating system. In particular, an additional hot water tank can be dispensed with.

[0012] It is further proposed that the heating system has at least one buffer tank which is arranged in the primary circuit or is intended to be arranged in the primary circuit. In at least one embodiment of the heating device, this has the buffer tank, in particular independently of the heating unit or alternative heating unit used. In an alternative embodiment of the heating device, this has at least one mounting location for attaching the buffer tank, so that it can be integrated into the primary circuit, in particular when one of the heating units is replaced by the alternative unit. When arranged in the primary circuit, the buffer tank is preferably fluidically integrated into a heat exchanger flow of the primary circuit leading to the heat exchanger.The buffer tank is preferably provided to supply the heat exchanger with heat, particularly at the start of a secondary-side water withdrawal, until a combination of the heating units and / or alternative heating unit can cover a heat demand associated with the water withdrawal. The at least two heating units comprise, for example, a first heating unit, in particular the fuel heating block, and at least one further heating unit, in particular the in-house unit of the heat pump. Depending on a configuration of the heating device and depending on a heat demand, a combination of the heating units and / or alternative heating unit can be, for example, only the first heating unit, only the further heating unit, only the alternative heating unit, the first heating unit and the further heating unit, or the alternative heating unit and the further heating unit.The inventive design advantageously allows the reliability of hot water preparation to be maintained independently of the heating units or alternative heating units used. In particular, a heating unit with a burner can be replaced by an electric alternative heating unit, in particular by an electric alternative heating unit with an advantageously low rated output, thereby advantageously resulting in minimal loss of comfort for a user with regard to hot water preparation. In particular, advantageously reliable hot water preparation can be achieved even with an electric alternative heating unit with a rated output between 3.5 kW and 9 kW.

[0013] It is further proposed that the heating system has a housing, in particular the housing already mentioned, wherein the at least two heating units together with the at least one buffer tank are at least partially arranged in the housing or wherein the alternative heating unit together with the at least one buffer tank are provided for at least partial arrangement in the housing. In an advantageously conversion-friendly embodiment of the heating device, the latter is provided to accommodate an assembly module of the heating system, on which the alternative heating unit and the buffer tank are pre-assembled and, in particular, fluidically connected to one another. The embodiment according to the invention allows the heating device to be kept advantageously compact. In particular, piping can be advantageously kept short and a pressure drop within the primary circuit can be advantageously kept small.In particular, an existing piping outside the housing can advantageously be retained unchanged when retrofitting the heating device with the buffer tank.

[0014] It is further proposed that the heating system comprise at least one fluid control element for selectively flowing through or at least partially bypassing the at least one buffer tank, the heat exchanger and / or at least one of the heating units or the alternative heating unit. The fluid control elements are preferably provided to adjust whether heat is stored in the buffer tank, in particular bypassing the heat exchanger, whether heat is extracted from the buffer tank, in particular bypassing one of the heating units and / or the alternative heating unit, and / or whether the buffer tank is bypassed, in particular for heat transfer from a combination of the heating units and / or the alternative heating unit to the heat exchanger. The at least one fluid control element is preferably designed as a valve, in particular as a 3-way valve, check valve, or continuous valve.The heating system preferably comprises at least one first fluid control element for adjusting whether or with which proportion of a total volume flow the buffer tank flows. The heating system preferably comprises at least one further fluid control element for determining a flow direction of the heat transfer medium through the buffer tank. If the heating device has the buffer tank, the heating device preferably also comprises the at least one fluid control element. Alternatively, the fluid control systems are intended to be installed together with the buffer tank in the heating device, in particular by pre-assembly on the assembly module. The design according to the invention advantageously allows a charging state of the buffer tank to be changed flexibly. In particular, the buffer tank can be controlled specifically depending on a duration until operation of one of the heating units and / or the alternative heating unit begins.In particular, the buffer tank's capacity can be advantageously kept small. In particular, the buffer tank's recharging time can be advantageously kept short.

[0015] It is further proposed that the at least one buffer tank comprises at least one warm fluid inlet and one warm fluid outlet for supplying the heat exchanger with heat, and a charging fluid connection for changing a charging state of the at least one buffer tank. The buffer tank is preferably fluidically integrated into the heat exchanger flow line by means of the warm fluid inlet and the warm fluid outlet. The warm fluid inlet is preferably provided for receiving the heat transfer medium from a combination of the heating units and / or the alternative heating unit. The warm fluid outlet is preferably provided for discharging the heat transfer medium to the heat exchanger. The buffer tank preferably has an alignment axis which, for operation of the buffer tank, is provided to be aligned at least substantially parallel to the earth's gravity."Substantially parallel" is understood here to mean, in particular, an alignment of a direction relative to a reference direction, in particular in a plane, wherein the direction has a deviation from the reference direction of, in particular, less than 8°, advantageously less than 5°, and particularly advantageously less than 2°. A plane running perpendicular to the alignment axis divides the buffer tank into a ceiling half and a floor half. The warm fluid outlet and the warm fluid inlet are preferably arranged in the ceiling half. A vertical distance running parallel to the alignment axis between the warm fluid outlet and the warm fluid inlet is particularly preferably less than 33%, preferably less than 25%, particularly preferably less than 15% of a maximum vertical extent of the buffer tank parallel to the alignment axis.A direct fluid path from the warm fluid inlet through the buffer tank to the warm fluid outlet preferably bypasses a large part of the buffer tank's receiving volume, in particular so that an inlet temperature of the heat transfer medium at the warm fluid inlet is at least substantially the same as an outlet temperature of the heat transfer medium at the warm fluid outlet, in particular up to a temperature difference of less than 3 K, preferably less than 1 K, particularly preferably less than 0.5 K. The charging fluid connection is preferably arranged in the bottom half of the buffer tank. A fluid path from the charging fluid connection through the buffer tank to the warm fluid outlet is preferably provided for removing heat from the buffer tank. A fluid path from the warm fluid inlet through the buffer tank to the charging fluid connection is preferably provided for storing heat in the buffer tank.The additional fluid control element is preferably connected to the charging fluid connection in order to adjust the flow direction of the heat transfer medium through the charging fluid connection. The inventive design advantageously allows the buffer tank to be recharged quickly. In particular, periods during which the buffer tank cannot adequately bridge a short-term heat demand from an additional secondary-side water withdrawal can be advantageously kept to a minimum.

[0016] Furthermore, it is proposed that a distance between the warm fluid outlet and the charging fluid connection be designed depending on the operating time of at least one of the heating units and / or the alternative heating unit. Preferably, a large portion, preferably at least 50%, particularly preferably more than 75%, in particular at least 90%, of the storage volume of the buffer tank is arranged between the charging fluid connection and the warm fluid outlet. After initiation of a secondary-side water withdrawal at the heat exchanger, a combination of the heating units and / or the alternative heating unit requires a operating time to reach an operating point that can cover the heat demand of the secondary-side water withdrawal. The buffer tank is preferably designed to store sufficient heat to bridge the maximum operating time required by the combination of the heating units and / or the alternative heating unit.The buffer tank can be designed to fully compensate for a lack of heat supply through the combination of the heating units and / or the alternative heating unit, so that the heat demand of the secondary-side water extraction is fully covered. Alternatively, the buffer tank is designed to maintain at least a specified minimum temperature of the extracted water at the heat exchanger during the initial operation period at a specified maximum water extraction rate. The distance is particularly preferably designed depending on a heating output and / or a start-up time of the second heating unit, depending on a heat capacity of the primary circuit, in particular the entire primary circuit, and / or depending on the desired comfort level, in particular the minimum temperature to be achieved.The design according to the invention advantageously allows for a high level of user comfort, particularly regardless of the type of heating unit and / or alternative heating unit used. In particular, comfort losses when switching from a heating unit with a burner to an electric alternative heating unit can be advantageously minimized.

[0017] Furthermore, a method for operating a heating system according to the invention in an embodiment with at least one buffer tank is proposed, wherein in at least one method step, service and / or drinking water is heated by means of the at least one buffer tank. The method is preferably triggered by a secondary-side water withdrawal at the heat exchanger. At the start of the secondary-side water withdrawal, the control and / or regulating unit directs the heat transfer medium within the primary circuit by means of the at least one fluid control element, preferably through the charging fluid connection to the warm fluid outlet and from there to the heat exchanger. In particular, a relatively cold heat transfer medium flows through the charging fluid inlet, displacing the relatively warm heat transfer medium already present in the buffer tank through the warm fluid outlet.At the start of the secondary-side water withdrawal, the control and / or regulating unit preferably operates a combination of the heating units and / or the alternative heating unit to cover a heat demand associated with the secondary-side water withdrawal. When the combination of the heating units and / or the alternative heating unit is ready for operation, the control and / or regulating unit directs the heat transfer medium, by means of the at least one fluid control element, through the combination of the heating units and / or the alternative heating unit to the warm fluid inlet. To cover the heat demand, the control and / or regulating unit preferably prefers the at least one additional heating unit to the first heating unit and / or the alternative heating unit.In particular, the control or regulating unit only puts the first heating unit or the alternative heating unit into operation when heat provision by the at least one further heating unit at a designated operating point of the further heating unit is insufficient to cover the heat demand. The buffer tank is preferably designed such that the combination of heating units and / or the alternative heating unit is ready for operation before the relatively cold heat exchanger reaches the warm fluid outlet. When the heat transfer medium enters through the warm fluid inlet, a flow of the heat transfer medium preferably bypasses at least a large part of the buffer tank and flows through the warm fluid outlet directly to the heat exchanger. Heat distribution within the buffer tank is essentially maintained during supply of the heat exchanger by means of the combination of heating units and / or alternative heating unit, apart from a thermalization process.After the secondary-side water withdrawal has ended, the control or regulating unit directs the heat transfer medium by means of the at least one fluid control element, preferably through the combination of heating units and / or the alternative heating unit to the warm fluid inlet to the charging fluid outlet, such that a relatively warm portion of the heat exchanger displaces a relatively cold portion of the heat exchanger from the buffer tank through the charging fluid outlet. Once the buffer tank is sufficiently charged with heat, the control or regulating unit preferably terminates operation of the combination of heating units and / or the alternative heating unit. The control or regulating unit can determine whether sufficient heat is stored in the buffer tank, for example, depending on a temperature sensor at the charging fluid outlet or within the buffer tank and / or depending on the duration of time for which the relatively warm heat transfer medium was fed into the buffer tank.The design according to the invention makes it possible to achieve an advantageously high level of user comfort, particularly regardless of the type of heating unit and / or alternative heating unit used. In particular, any loss of comfort when switching from a heating unit with a burner to an electric alternative heating unit can be advantageously kept to a minimum. Furthermore, the start-up time of a heating unit designed as a heat pump can advantageously be buffered, so that in many situations the heat pump can advantageously be used even without the support of the other heating unit, in particular one designed as a fuel heating block, to cover an advantageously large, in particular the entire, heat requirement, in particular without any loss of comfort. Furthermore, the heating unit designed as a heat pump can advantageously be designed to be small, particularly without any loss of comfort.Furthermore, an advantageously high ratio of annually used renewable energy to used fossil energy can be achieved.

[0018] In a further embodiment of the invention, a heating device, in particular a hybrid heating device, is proposed, which has a housing, a heating unit designed as a heat pump, and a heating unit designed as a fuel heating block, in particular as a gas heating block, which are each arranged at least partially within the housing. In at least one embodiment, the heating device has the heat exchanger, which is preferably arranged within the housing. Alternatively or additionally, the heating device has the fluid connections for an external heat exchanger of the hot water storage tank. In an embodiment with a heat exchanger, the heating device preferably has the buffer tank and / or a mounting point provided for arranging the buffer tank, wherein the buffer tank and / or the mounting point are preferably arranged within the housing.By means of a corresponding design, a particularly compact and flexible heating device can be created, in particular if one of the heating units is intended for replacement.

[0019] The heating system according to the invention, the method according to the invention, and the heating device according to the invention are not intended to be limited to the application and embodiment described above. In particular, the heating system according to the invention, the method according to the invention, and the heating device according to the invention may have a number of individual elements, components, units, and method steps that differs from the number stated herein to fulfill a function described herein. Drawings

[0020] Further advantages will become apparent from the following description of the drawings. The drawings illustrate three exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0021] It shows: Fig. 1 is a schematic representation of a heating system according to the invention with a heating device according to the invention and with an alternative heating unit that can be added interchangeably to the heating device according to the invention, Fig. 2 is a schematic representation of an alternative embodiment of a heating system according to the invention with a heating device according to the invention without an internal buffer tank, which is designed in particular as a flow heater and for which no external hot water tank is provided, Fig. 3 is a schematic hydraulic plan of the heating device according to the invention Figure 2 in a configuration with a first heating unit, Fig. 4 a schematic hydraulic diagram of the heating device according to the invention Figure 2in a configuration with an alternative heating unit, Fig. 5 a schematic flow diagram of a method according to the invention, Fig. 6 a schematic representation of a further alternative embodiment of a heating system according to the invention with a heating device according to the invention with an internal buffer tank and Fig. 7 a schematic hydraulic plan of the heating device according to the invention from Figure 6 . Description of the embodiment

[0022] The Figure 1 shows a schematic representation of a heating system 10a. The heating system 10a has a heating device 12a. The heating device 12a is designed as a hybrid heating device. The heating device 12a is intended to cover the heat demand of a residential building 24a. The heat demand of the residential building 24a is formed at least predominantly by a living space temperature control and by a service and / or drinking water temperature control.

[0023] The heating device 12a has a first heating unit 14a. The first heating unit 14a is designed as a fuel heating block. The first heating unit 14a is designed as a gas heating block. The heating device 12a has a second heating unit 16a. The second heating unit 16a is designed as at least part of a heat pump. The second heating unit 16a is designed as an indoor unit of a heat pump. The indoor unit is connected to an outdoor unit 26a of the heat pump, which is arranged outside the residential building 24a. The second heating unit 16a is intended to provide temperatures up to 55°C. The first heating unit 14a is intended to provide temperatures above 55°C. Therefore, if temperatures, e.g. service and / or drinking water temperatures of more than 55°C, are required in the residential building 24a, the first heating unit 14a supports the second heating unit 16a.The first heating unit 14a can also provide support in particularly cold outside temperatures.

[0024] The residential building 24a includes a space heating system 28a. The space heating system 28a is embodied, for example, as underfloor heating. However, alternative space heating systems are of course also conceivable. The heating device 12a is provided for operating the space heating system 28a. The residential building 24a includes a hot water tank 30a. The heating device 12a is provided for heating the domestic and / or drinking water in the hot water tank 30a.

[0025] The heating system 10a, in particular the heating device 12a, has a housing 20a. The first heating unit 14a is arranged in the housing 20a. The second heating unit 16a is at least partially arranged in the housing 20a. The indoor unit of the heat pump is arranged in the housing 20a. The heating system 10a, in particular the heating device 12a, has an electronic control and / or regulating unit 22a. The control and / or regulating unit 22a is arranged within the housing 20a. The control and / or regulating unit 22a is provided at least to control and / or regulate the first heating unit 14a. The control and / or regulating unit 22a is provided at least to control and / or regulate the second heating unit 16a. The heating system 10a, in particular the heating device 12a, has a user interface 32a. The user interface 32a allows adjustment of the control and / or regulating unit 22a, the first heating unit 14a and / or the second heating unit 16a.The user interface 32a can be accessed or operated via a surface of the housing 20a. Alternatively, wireless operation via a remote control or another mobile device (e.g., a smartphone) is also conceivable. The heating system 10a, in particular the heating device 12a, has a hydraulic system 34a. The hydraulic system 34a is arranged at least partially, preferably predominantly or entirely, in the housing 20a. The control and / or regulating unit 22a is provided at least to control and / or regulate the hydraulic system 34a.

[0026] The heating system 10a has an alternative heating unit 18a. The alternative heating unit 18a is designed as an electric heating block. The alternative heating unit 18a could alternatively be designed as a hydrogen heating block. The alternative heating unit 18a is intended to provide temperatures above 55°C. The alternative heating unit 18a is intended to be arranged within the housing 20a. The first heating unit 14a, designed as a fuel heating block, is intended for replacement. The first heating unit 14a is intended to be replaced with the alternative heating unit 18a. The alternative heating unit 18a can replace the first heating unit 14a in the heating device 12a. The alternative heating unit 18a can be mounted in the housing 20a instead of the first heating unit 14a. In this case, it may be necessary to remove the first heating unit 14a from the housing 20a.The control and / or regulating unit 22a is provided at least to control and / or regulate the alternative heating unit 18a. The alternative heating unit 18a is compatible with the hydraulic system 34a of the heating system 10a. The alternative heating unit 18a is compatible with the user interface 32a of the heating system 10a. The alternative heating unit 18a is compatible with the hot water tank 30a. The alternative heating unit 18a is compatible with the space heater 28a. The alternative heating unit 18a is compatible with the second heating unit 16a. The alternative heating unit 18a is provided to process a signal from at least one of the heating units 14a, 16a, in particular the second heating unit 16a, of the heating device 12a. Replacing the first heating unit 14a with the alternative heating unit 18a is a plug-and-play process.

[0027] It is conceivable that after replacement or installation of the alternative heating unit 18a, it is electrically connected to a signal line that was previously intended to control a fan of the first heating unit 14a replaced by the alternative heating unit 18a, in particular a fan of the gas heating block. The power supply of the fan of the gas heating block can thus advantageously be reused to power the electronic heating block, in particular at least one control board of the electronic heating block. Furthermore, a particularly simple conversion can advantageously be enabled, which in particular has a minimal impact on a control design or a wiring harness of the heating system 10a.

[0028] In the Figures 2 to 7Two further embodiments of the invention are shown. The following descriptions and the drawings are essentially limited to the differences between the embodiments, whereby with regard to components with the same designation, in particular with regard to components with the same reference numerals, reference is also made to the drawings and / or the description of the other embodiments, in particular to the Figure 1 , can be referred to. To distinguish the embodiments, the letter a is added to the reference numerals of the embodiment in the Figure 1 In the examples of the Figures 2 to 7 the letter a is replaced by the letters b to c.

[0029] Figure 2shows a heating system 10b with a heating device 12b. The heating device 12b is designed, in particular, as a hybrid heating device. The heating device 12b comprises at least a first heating unit 14b and a second heating unit 16b. The first heating unit 14b is preferably designed as a fuel heating block, in particular a gas heating block, and the second heating unit 16b preferably comprises a heat exchanger of a heat pump. The heating system 10b comprises an alternative heating unit 18b, which is designed, in particular, as an electric heating block. The heating device 12b is preferably designed such that the first heating unit 14b is interchangeable with the alternative heating unit 18b.

[0030] The heating system 10b comprises a primary circuit. The primary circuit comprises at least one heat exchanger 36b, which is different from the heating units 14b, 16b and / or the alternative heating unit 18b, for heating domestic and / or drinking water. The heat exchanger 36b is preferably designed as a continuous-flow heater, in particular at least when operated with the first heating unit 14b. The heating system 10b can in particular be connected to the hot water tank 30a of Figure 1For operation with the alternative heating unit 18b, which in particular has a lower heating output and / or a longer operating time than the first heating unit 14b, the heating system 10b comprises a buffer tank 38b, which is intended to be integrated into the heating device 12b when the alternative heating unit 18b is installed. Such a configuration allows the already installed heat exchanger 36b to be used with the full range of functions even with the alternative heating unit 18b, with advantageously low retrofitting costs.

[0031] Figure 3 and Figure 4 each show a hydraulic diagram of the heating device 12b, 12b'. In Figure 3 the heating device 12b is shown in a configuration with the first heating unit 14b. In Figure 4The heating device 12b' is shown in a configuration in which the first heating unit 14b has been replaced by the alternative heating unit 18b. To distinguish the configurations, the reference numerals of the Figure 4 an apostrophe is added.

[0032] The primary circuit preferably comprises a fluid conveying unit 56b, 56b', in particular a pump, for circulating a heat transfer medium, in particular heating water, within the primary circuit. The primary circuit preferably comprises the first heating unit 14b or the alternative heating unit 18b' and the second heating unit 16b, 16b'. The heating unit 14b or the alternative heating unit 18b' is preferably arranged downstream of the fluid conveying unit 56b, 56b'. The second heating unit 16b, 16b' is arranged, for example, upstream of the fluid conveying unit 56b, 56b'. In particular, the second heating unit 16b, 16b' and the first heating unit 14b or the alternative heating unit 18b' are fluidically connected or switchable in series. The primary circuit preferably comprises a heat exchanger flow 66b, 66b' connected to a fluid outlet of the first heating unit 14b or the alternative heating unit 18b'.The heat exchanger flow 66b, 66b' is preferably connected to a fluid inlet of the heat exchanger 36b, 36b'. The primary circuit preferably comprises a heat exchanger return 68b, 68b', which is connected to a fluid outlet of the heat exchanger 36b, 36b' and to a fluid inlet of the second heating unit 16b, 16b'. The heat exchanger 36b, 36b' preferably comprises a secondary side with a water source connection 64b, 64b' for receiving, in particular untempered, drinking and / or service water and a water outlet connection 62b' for discharging the drinking and / or service water at a predetermined target temperature. To heat the drinking and / or service water to the target temperature and, if necessary, additionally to operate a space heater 28b (cf. Fig. 2 ) a heat requirement is required, which is to be provided by a combination of the heating units 14b, 16b, 16b' and / or the alternative heating unit 18b'.

[0033] Preferably, the primary circuit comprises at least one heating flow 58b, 58b' branching off from the heat exchanger flow 66b, 66b' for supplying the space heating 28b with the heat transfer medium (cf. Fig. 2). A heating return 60b, 60b' of the primary circuit preferably opens into the heat exchanger return 68b'. The heating system 10b preferably comprises at least one heating fluid control element 54b, 54b' for adjusting a distribution of a total volume flow in the primary circuit to at least the space heater 28b, 28b' and the heat exchanger 36b, 36b'. The heating fluid control element 54b, 54b' is arranged here, for example, in the heat exchanger flow 66b, 66b', or alternatively in the heat exchanger return 68b, 68b'. The heating device 12b, 12b' preferably comprises a housing 20b, 20b', in which the first heating unit 14b or the alternative heating unit 18b', the second heating unit 16b, 16b', the fluid conveying unit 56b, 56b' and the heat exchanger 36b, 36b' and in particular the heat exchanger flow 66b, 66b', the heat exchanger return 68b, 68b' and the heating fluid actuating element 54b are arranged together.

[0034] In the configuration of the heating device 12b' for operation with the alternative heating unit 18b', the buffer tank 38b' is arranged in the primary circuit. The buffer tank 38b' is preferably integrated into the heat exchanger flow 66b', preferably downstream of the heating fluid actuator 54b'. The buffer tank 38b' comprises a warm fluid inlet 44b' and a warm fluid outlet 46b' for supplying the heat exchanger 36b' with heat. The warm fluid inlet 44b' is arranged within the heat exchanger flow 66b', preferably upstream of the warm fluid outlet 46b'. The warm fluid inlet 44b' is preferably connected to a section of the heat exchanger flow 66b' connected to the alternative heating unit 18b'. The warm fluid outlet 46b' is preferably connected to a section of the heat exchanger flow 66b' connected to the heat exchanger 36b'.The warm fluid inlet 44b' and the warm fluid outlet 46b' are preferably both arranged in a top half of the buffer tank 38b'. The buffer tank 38b' comprises a charging fluid connection 48b' for changing a charging state of the buffer tank 38b'. The charging fluid connection 48b' is preferably arranged in a bottom half of the buffer tank 38b'. The charging fluid connection 48b' is preferably fluidically connected to the heat exchanger return 68b' and / or the heating return 60b' by means of a charging line of the heating system 10b. The charging fluid connection 48b' is preferably connected to a fluid outlet of the fluid delivery unit 56b' by means of a discharge line of the heating system 10b. The discharge line preferably branches off upstream of the alternative heating unit 18b' from a supply line of the primary circuit, which leads from the fluid conveying unit 56b' to the alternative heating unit 18b'.A distance between the warm fluid outlet 46b' and the charging fluid connection 48b' is designed depending on an operating time of the second heating unit 16b' and / or the alternative heating unit 18b'.

[0035] The heating system 10b comprises at least one fluid control element 40b', 42b' for selectively flowing through or at least partially bypassing the buffer tank 38b', the heat exchanger 36b', and / or the alternative heating unit 18b'. The heating system 10b here comprises, for example, a first fluid control element 40b', which is designed in particular as a 3-way valve. The first fluid control element 40b' is preferably connected to the charging fluid connection 48b' and is provided to fluidically connect the charging fluid connection 48b' selectively to the charging line or the discharging line. The heating system 10b comprises, for example, a further fluid control element 42b'. The further fluid control element 42b' is preferably arranged in the supply line between the fluid delivery unit 56b' and the alternative heating unit 18b' and is provided to fluidically connect the fluid delivery unit 56b' optionally to the alternative heating unit 18b' or to the charging line.

[0036] The buffer tank 38b', the fluid control elements 40b', 42b', the charging line and the discharging line are preferably arranged together in the housing 20b', in particular together with the aforementioned components already arranged in the housing 20b'.

[0037] Figure 5 shows a method 50b for operating the heating system 10b in the Figure 4shown configuration. In at least one method step of method 50b, the service and / or drinking water is heated by means of the buffer tank 38b'. Method 50b is preferably triggered by a water withdrawal on the secondary side of the heat exchanger 36b'. Method 50b preferably comprises a buffer step 70b. In buffer step 70b, the control or regulating unit 22b takes temperature or at least a minimum temperature. In buffer step 70b, the control and / or regulating unit 22b uses the fluid control elements 40b', 42b' to conduct the heat transfer medium from the fluid conveying unit 56b' via the discharge line to the charging fluid connection 48b' in the buffer tank 38b'. The heat transfer medium stored in the buffer tank 38b', in particular the relatively warm one, is displaced and conducted through the heat exchanger 36b' via the warm fluid outlet 46b'.The heat transfer medium is preferably passed through the heat exchanger 36b' and preferably through the second heating unit 16b' back to the fluid delivery unit 56b'. In the buffer step 70b, the alternative heating unit 18b' is preferably bypassed or fluidically connected in parallel to the buffer tank 38b' by means of the further fluid control element 42b' for simultaneous supply of the space heater 28.

[0038] The method 50b preferably includes a regular output 72b, which is initiated by the control or regulating unit 22b when the second heating unit 16b' is ready for operation, in particular when it has reached a predetermined operating point. At the start of the regular output 72b, the control or regulating unit 22b directs the heat transfer medium by means of the fluid control elements 40b', 42b', preferably from the fluid delivery unit 56b' through the alternative heating unit 18b' to the warm fluid inlet 44b' and, in particular bypassing a large part of a receiving volume of the buffer tank 38b', via the warm fluid outlet 46b' to the heat exchanger 36b'. The heat transfer medium is preferably guided through the heat exchanger 36b' and preferably through the second heating unit 16b' back to the fluid delivery unit 56b'. In the regular output 72b, the alternative heating unit 18b' can be switched on or off, in particular depending on the heat demand to be covered.In particular, the control or regulating unit 22b only operates the alternative heating unit 18b' when the heating output of the second heating unit 16b is insufficient to meet the heat demand and / or when increasing the heating output of the second heating unit 16b would be less efficient relative to the electrical energy demand than operating the alternative heating unit 18b'. Preferably, the control or regulating unit 22b closes the charging fluid connection 48b' in the regular outlet 72b by means of the fluid control elements 40b', 42b'.

[0039] The method 50b preferably includes a recharging step 74b, which is carried out after the water withdrawal on the secondary side of the heat exchanger 36b' has ended. In the recharging step 74b, the control or regulating unit 22b uses the fluid control elements 40b', 42b' to direct the heat transfer medium from the fluid delivery unit 56b' through the alternative heating unit 18b to the warm fluid inlet 44b'. The heat transfer medium located in the buffer tank 38b', in particular the relatively cold heat transfer medium, is displaced via the charging fluid connection 48b' and guided via the charging line back into the heat exchanger return 68b' and / or into the heating return 60b'. The heat transfer medium is preferably guided through the second heating unit 16b' back to the fluid delivery unit 56b'.At the end of the recharging step 74b, particularly when the buffer tank 38b' is sufficiently filled with heat, the control and / or regulating unit 22b preferably closes the charging fluid connection 48b' by means of the first fluid control element 40b' and / or the warm fluid connection by means of the heating fluid actuating element 54b'. Depending on a further heat requirement of the space heater 28b, the control or regulating unit 22b can switch off the second heating unit 16b', the alternative heating unit 18b' and / or the fluid delivery unit 56b', place them into standby mode, or continue to operate them, particularly at a different operating point.

[0040] Figure 6 and Figure 7show a heating system 10c with a heating device 12c. The heating device 12c is designed in particular as a hybrid heating device. The heating device 12c preferably comprises a first heating unit 14c, which is designed, for example, as a fuel heating block. The heating device 12c comprises a second heating unit 16c, which is designed, for example, as an in-house unit of a heat pump. The heating system 10c comprises an alternative heating unit 18c, which is designed, in particular, as an electric heating block. The heating device 12c is preferably designed such that the first heating unit 14c is interchangeable with the alternative heating unit 18c. The heating system 10c comprises at least one heat exchanger 36c and a buffer tank 38c, which are integrated into a primary circuit of the heating device 12c. The heating system 10c comprises a housing 20c.The at least two heating units 14c, 16c or the second heating unit 16c and the alternative heating unit 18c are arranged together with the buffer tank 38c at least partially in the housing 20c.

[0041] In a configuration with buffer tank 38c and with a first heating unit 14c designed as a fuel heating block, a Figure 4A method analogous to the method 50b shown can be carried out, wherein in all method steps described above, depending on the configuration, the first heating unit 16c and the alternative heating unit 18c are interchangeable as desired. In particular, in a regular version of the method, the first heating unit 14c is preferably only put into operation by a control and / or regulating unit 22c of the heating system 10c when the heating output of the further heating unit 16c is insufficient to cover a predetermined heat requirement. By means of such a configuration, the consumption of fossil energy sources by the heating device 12c can advantageously be kept low in relation to the use of electrical power, in particular to the use of renewable energy sources. In particular, the buffer tank 38c can advantageously keep user comfort high during commissioning of the second heating unit 16c even without the use of the first heating unit 14c.

Claims

1. Heating system (10a; 10b; 10c) with a heating device (12a; 12b; 12c), in particular a hybrid heating device, which has at least two heating units (14a, 16a; 14b, 16b; 14c, 16c), and with an alternative heating unit (18a; 18b; 18c), which is designed in particular as an electric heating block.

2. Heating system (10a; 10b; 10c) according to claim 1, characterized in that at least one of the at least two heating units (14a, 16a; 14b, 16b; 14c, 16c) of the heating device (12a; 12b; 12c) is provided for exchange with the alternative heating unit (18a; 18b; 18c).

3. Heating system (10a; 10b; 10c) according to one of the preceding claims, characterized in that the heating device (12a; 12b; 12c) has a heating unit (14a; 14b; 14c) designed as a fuel heating block, in particular a gas heating block.

4. Heating system (10a; 10b; 10c) according to one of the preceding claims, characterized in that the heating device (12a; 12b; 12c) has a heating unit (16a; 16b; 16c) designed as a heat pump.

5. Heating system (10a; 10b; 10c) at least according to claim 2 and 3, characterized in that the fuel heating block is intended for replacement.

6. Heating system (10a; 10b; 10c) according to one of the preceding claims, characterized by a housing (20a; 20b; 20c), wherein the at least two heating units (14a, 16a; 14b, 16b; 14c, 16c) of the heating device (12a; 12b; 12c) are each arranged at least partially within the housing (20a; 20b; 20c).

7. Heating system (10a; 10b; 10c) according to claim 6, characterized in that the alternative heating unit (18a; 18b; 18c) is arranged within the housing (20a; 20b; 20c) or is intended to be arranged within the housing (20a; 20b; 20c).

8. Heating system (10a; 10b; 10c) according to one of the preceding claims, characterized by a control and / or regulating unit (22a; 22b; 22c) which is intended to control and / or regulate the alternative heating unit (18a; 18b; 18c).

9. Heating system (10a; 10b; 10c) according to one of the preceding claims, characterized in that the alternative heating unit (18a; 18b; 18c) is provided to process a signal from at least one of the heating units (14a, 16a; 14b, 16b; 14c, 16c) of the heating device (12a; 12b; 12c).

10. Heating system (10b; 10c) according to one of the preceding claims, characterized by a primary circuit which comprises at least one heat exchanger (36b; 36c) different from the heating units (14b, 16b; 14c, 16c) and / or the alternative heating unit (18b; 18c) for heating domestic and / or drinking water.

11. Heating system (10b; 10c) according to claim 10, characterized by at least one buffer tank (38b; 38c) which is arranged in the primary circuit or is intended to be arranged in the primary circuit.

12. Heating system (10b; 10c) according to claim 11, characterized bya housing (20b; 20c), wherein the at least two heating units (14b, 16b; 14c, 16c) together with the at least one buffer tank (38b; 38c) are arranged at least partially in the housing (20b; 20c) or wherein the alternative heating unit (18b; 18c) together with the at least one buffer tank (38b; 38c) are provided for an at least partial arrangement in the housing (20b; 20c).

13. Heating system (10b; 10c) according to one of claims 11 or 12, characterized by at least one fluid control element (40b, 42b; 40c, 42c) for selectively flowing through or at least partially bypassing the at least one buffer tank (38b; 38c), the heat exchanger (36b; 36c) and / or at least one of the heating units (14b; 14c) or the alternative heating unit (18b; 18c).

14. Heating system (10b; 10c) according to one of claims 11 to 13, characterized in thatthe at least one buffer tank (38b; 38c) comprises at least one warm fluid inlet (44b; 44c) and one warm fluid outlet (46b; 46c) for supplying the heat exchanger (36b; 36c) with heat and a charging fluid connection (48b; 48c) for changing a charging state of the at least one buffer tank (38b; 38c).

15. Heating system (10b; 10c) according to claim 14, characterized in that a distance between the warm fluid outlet (46b; 46c) and the charging fluid connection (48b; 48c) is designed depending on an operating time of at least one of the heating units (14b; 14c) and / or the alternative heating unit (18b; 18c).

16. Method (50b) for operating a heating system (10b; 10c) according to one of claims 11 to 15, wherein in at least one method step, domestic and / or drinking water is heated by means of the at least one buffer tank (38b; 38c).

17. Heating device (12a; 12b; 12c) for a heating system (10a; 10b; 10c) according to one of claims 1 to 15.

18. Heating device (12a; 12b; 12c), in particular hybrid heating device, preferably according to claim 17, characterized by a housing (20a; 20b; 20c), a heating unit (16a; 16b; 16c) designed as a heat pump and a heating unit (14a; 14b; 14c) designed as a fuel heating block, in particular a gas heating block, which are each arranged at least partially within the housing (20a; 20b; 20c).

19. Alternative heating unit (18a; 18b; 18c) of a heating system (10a; 10b; 10c) according to one of claims 1 to 15.

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