Hybrid heater and use of deflector

Abstract

A hybrid heating appliance (1) is proposed, comprising a boiler (3) configured for the combustion of a fuel, and an air / water heat pump (4) with an evaporator (8), wherein the boiler (3) and heat pump (4) are arranged within a common housing (2) and are configured to draw in a supply air flow (23) from a common supply air connection (29), and an exhaust gas flow (22) from the boiler (3) is directed to the evaporator (8) of the heat pump (4), wherein a deflector (6) is arranged and configured within the housing (2) such that the supply air flow (23) entering the housing (2) from the supply air connection (29) is guided past the boiler (3) on a first air path (25) in such a way that there is no thermal contact between the first air path (25) or the supply air flow (23) and the boiler (3), and subsequently to the evaporator (8). and / or is supplied to the boiler (3).The invention enables energy-efficient operation of the hybrid heating device (1) in conjunction with a simple and compact design.

Description

[0001] The invention relates to a hybrid heating device and the use of a deflector.

[0002] With the increasing focus on sustainable energy sources for heating buildings and providing hot water, hybrid heating systems have been developed that combine a heat pump, usually an air-to-water heat pump, with a conventional boiler. This allows for energy-saving reductions in the boiler's operating time, and particularly during transitional seasons or periods of low heating demand, the system can be powered solely by the heat pump. When heating demand is high, for example, due to cold weather or a high hot water requirement, the boiler can quickly and reliably provide a high heat output to meet all heating needs.

[0003] Such a hybrid heating system is described in EP 2 868 984 A1. It comprises an air / liquid heat pump and a boiler for heating domestic hot water. The heat pump's condenser can be divided into two sections, with the first section carrying incoming cold domestic hot water. A disadvantage of this type of heating system, in conjunction with an air supply for the boiler and heat pump, is the considerable installation effort and space required.

[0004] EP 2 273 203 A2 presents a hybrid heating appliance that can be housed in a single unit, thus featuring a compact design. This appliance comprises an air-to-water heat pump supplied by the boiler's intake air and a boiler. A disadvantage is the low energy efficiency of this heating system. EP 2 926 059 B1 also describes a similar hybrid heating appliance with energy efficiency that could be improved.

[0005] It is therefore an object of the invention to at least partially alleviate or solve the problems described with reference to the prior art. In particular, a hybrid heating device is to be provided that operates with exceptional energy efficiency and has a simple design. Furthermore, it is desirable that the hybrid heating device has a compact design and can be arranged in a casing or housing.

[0006] These problems are solved by the features of the independent claims. Further advantageous embodiments of the solution proposed here are specified in the independent claims. It should be noted that the features listed in the dependent claims can be combined with one another in any technologically meaningful way and define further embodiments of the invention. Furthermore, the features specified in the claims are further specified and explained in the description, which also presents further preferred embodiments of the invention.

[0007] This is achieved using a hybrid heating unit comprising a boiler designed for burning fuel and an air-to-water heat pump with an evaporator. The boiler and heat pump are housed within a common casing and draw air from a shared intake. Exhaust gas from the boiler is directed to the heat pump's evaporator. A deflector is positioned within the casing such that air flowing into the casing from the intake is guided along a first air path past the boiler in such a way that there is no thermal contact between this first air path or the intake air flow and the boiler. The air is then subsequently directed to the evaporator and / or the boiler.

[0008] The hybrid heating unit can supply a building with heating and / or hot water and can be installed either freestanding or, in particular, wall-mounted. Specifically, the heating unit can deliver a heat output of up to 50 kilowatts.

[0009] The boiler of the hybrid heating appliance can be a conventional fuel-burning boiler. The boiler can add a mass flow of fuel, corresponding to a predetermined combustion air ratio (lambda, air-fuel ratio), to the combustion airflow drawn in by a secondary conveying device. The resulting combustion mixture can be fed via a mixture channel to a burner in the boiler, from where it exits into a combustion chamber of the heating appliance and is combusted. For this purpose, the boiler can include an ignition device to ignite the combustion mixture at the burner. At least one heat exchanger can be designed to transfer the heat generated during fuel combustion in the combustion chamber to a heat transfer medium circulating in a heating circuit. The hybrid heating appliance can also include a circulation pump for the heating circuit.

[0010] The exhaust gas stream, or combustion products, is fed from the combustion chamber to the heat pump's evaporator via an exhaust gas inlet. The evaporator's first conveying unit can draw in the exhaust gas stream from the exhaust gas inlet and / or an intake air stream from the first air path. For this purpose, the first conveying unit can be located downstream of the evaporator in the direction of airflow. After passing through the evaporator, the airflow or exhaust gas stream can be discharged into the building's exhaust system via an exhaust port on the housing. The evaporator is thus located outside the exhaust gas inlet and outside the exhaust duct within the housing and can advantageously have a large heat exchange surface.

[0011] The boiler can be specifically designed to burn a fuel gas. This fuel gas can be, for example, a fossil gas such as natural gas or hydrogen. The boiler can be designed, for instance, to burn a fuel gas with a (pure) hydrogen content of at least 80 percent, 90 percent, or 95 percent, or even pure hydrogen. In particular, the boiler can be a condensing boiler or a condensing gas boiler, which is designed to cool the exhaust gas to such an extent that the water vapor it contains condenses, thus making the heat of condensation usable.

[0012] The boiler can have a gas valve to control the mass flow of fuel gas, which typically includes a gas safety valve and a gas control valve. The gas control valve can be, in particular, a stepper motor valve capable of setting a defined mass flow of fuel gas. Alternatively, the gas control valve can also deliver a mass flow of fuel gas according to a transmitted control pressure. This control pressure can be measured in a Venturi device and serve as a measure of the delivered mass flow of combustion air. This configuration is also known as a pneumatic gas-air system. The safety valve is designed to prevent the escape of unburned hydrogen and, for example, during the boiler's start-up process, is only released after the supply system has been activated to a suitable starting power. The aforementioned components can be any part of the boiler itself.

[0013] The boiler can adjust its burner output to the demand, a process also known as "modulation." Upon detecting a change in heat demand, for example, by taking into account the flow and return temperatures of the heating circuit connected to the hybrid boiler, a control unit of the hybrid boiler can adjust the output of the secondary heating system, and thus the mass flow of the supply air used by the boiler as combustion air, to the heat demand or the heat output of the heat pump. Simultaneously, a control system adjusts the fuel mass flow to the changing supply air flow.

[0014] The heat pump can be a conventional heat pump in which a refrigerant circulates in a refrigeration cycle and transfers heat. The heat pump comprises an evaporator, which can absorb heat from the supply air stream and / or the exhaust gas stream of the boiler, and a condenser, designed to transfer heat to the heat transfer fluid circulating in the heating circuit. For this purpose, a first circulation system of the heat pump may be provided, which supplies air to the evaporator or circulates air through it. Viewed in the direction of flow of the heat transfer fluid in the heating circuit, the condenser can be located upstream of at least one heat exchanger that is in operative communication with the boiler. In the evaporator, the refrigerant can change from a liquid phase to a gaseous phase, thereby extracting heat from the supply air stream and / or the exhaust gas stream of the boiler.In the condenser, the refrigerant can transition from the gaseous to the liquid phase and transfer heat to the heat transfer fluid of the heating circuit. A compressor and an expansion valve can be located on opposite sides between the evaporator and condenser to establish suitable pressure conditions for the phase transitions.

[0015] The hybrid heating unit can also include the provision of hot water (heated domestic hot water). For this purpose, a hot water heat exchanger can be arranged in a bypass between the flow and return of the heating circuit, and a three-way valve can be used to initiate flow through this hot water heat exchanger.

[0016] The hybrid heating unit can comprise a single housing in which the heat pump and the boiler are located together. In other words, all components of the hybrid heating unit can be housed within a single casing. The air intake can be connected to the housing in such a way that the supply air flow from the intake is directed into the interior of the housing. The first pump of the heat pump and the second pump of the boiler draw air from the first air passage located inside the housing. Additionally, when the boiler is switched on, its exhaust gas is directed to the evaporator via the exhaust gas inlet. Downstream of the evaporator, an exhaust gas duct can lead to the exhaust gas connection of the housing.

[0017] The hybrid heating unit can include a control and monitoring device that regulates and controls its operation. This device can be electrically or electronically connected to at least the first and / or second pumping unit, the heat pump or its components, and the boiler.

[0018] The deflector of the hybrid heating appliance can also be understood as an air guide device and is arranged and configured to direct the supply air flow drawn in from the supply air connection past the boiler via a first air path, to which a first supply air flow is assigned. "Bypassing" in this context means that there is virtually no thermal contact between the first air path or supply air flow and the boiler or combustion chamber, and consequently, heat transfer from the boiler or combustion chamber to the first air path or supply air flow is either not possible or virtually non-existent. This advantageously prevents heat losses from the boiler to the first supply air flow and increases the efficiency of the hybrid heating appliance.

[0019] This results in a first air path, to which a first supply air stream is assigned, passing by the boiler or combustion chamber. The first conveying device and / or the second conveying device can draw supply air from the first air path. The deflector is designed to direct the supply air flowing from or drawn in from the supply air connection into the first air path. The first air path can be limited by the deflector and / or components of the hybrid heating unit and may be a section of the interior of the housing. It is understood that further deflectors or air guide devices may also be provided to limit the first air path.

[0020] The evaporator typically requires a very high airflow to operate efficiently, often in the range of 200 cubic meters per hour. Such a large airflow would cause significant heat loss from the boiler or combustion chamber if the (first) supply air stream were in thermal contact with the boiler or combustion chamber. The deflector is specifically designed to direct the (first) supply air stream directly to the evaporator, thereby minimizing / reducing thermal contact between the first supply air stream and the boiler, and thus reducing heat losses and increasing the efficiency of the hybrid heating system.

[0021] According to one embodiment, the housing of the hybrid heating appliance can have a front and a back, with the back being designed for mounting the hybrid heating appliance on a wall, and the first air path adjoining the back of the housing. In this respect, the first supply air flow can be arranged between a rear wall forming the back of the housing and the boiler or combustion chamber. At least one (actively adjustable) component of the heat pump, in particular the compressor, the condenser, and / or the evaporator, can be arranged in the area of ​​the back of the hybrid heating appliance. At least one component of the boiler, in particular the burner and / or the associated heat exchanger and / or the gas valve, can be arranged on or in the area of ​​the front.

[0022] According to one embodiment, the deflector can be configured to split the supply air flow entering the housing from the air intake into a first and a second air path. A predetermined portion of the supply air flow is drawn in by the second conveying device and flows around the outside of the boiler via the second air path for cooling. This embodiment enables targeted cooling of the boiler or combustion chamber and prevents damage due to overheating. The division of the supply air flow into the first and second air paths can be such that the second air path is sufficient to prevent damage due to overheating of the boiler and thus limit heat losses to the level necessary for cooling.

[0023] According to one embodiment, a third airflow can be supplied to the boiler as combustion air via a third air path, originating from the first air path or supply air flow. If the first air path adjoins the rear of the housing, the third air path can lead from the rear of the housing towards the front of the housing and an intake opening of the boiler located there.

[0024] According to one embodiment, the boiler can include a gas valve and / or an electronic component in the area of ​​the third air path, arranged such that the gas valve and / or the electronic component are cooled by the air flowing in the third air path. The electronic components can, for example, be a control and regulation unit for the heating appliance or heat pump and / or the boiler. The electronic components can be arranged in a so-called E-box, which is positioned in or on the third air path in such a way that the E-box is surrounded or flowed through by the third supply air stream, thus allowing the electronic components to be cooled.

[0025] According to one embodiment, the air intake connection of the hybrid heating appliance housing can be arranged coaxially with the exhaust gas connection for drawing in ambient air or the supply air stream. Such systems are also referred to as air-exhaust systems, in which the supply air stream is guided around the exhaust gas stream, thus advantageously promoting heat transfer from the exhaust gas stream to the supply air stream. In particular, the supply air stream can enter the housing of the hybrid heating appliance, and the conveying device can draw the supply air stream from inside the housing. A deflector designed for this purpose can include an annular area that collects the supply air stream from the supply air connection.

[0026] The proposed hybrid heating appliance thus enables at least three operating modes. In the first mode, pure heat pump operation, the entire initial supply air flow is drawn in by the first conveying unit and passed through the evaporator. In the second mode, combined operation, both the boiler and the heat pump are in operation, and the initial supply air flow is distributed proportionally between the evaporator and the boiler. The portion of the initial supply air flow supplied to the boiler as combustion air can be routed through the third air path, advantageously preventing waste heat from the boiler from damaging electronic components and / or the gas valve. In the third mode, only the boiler can be in operation, and its exhaust gases are fed through the evaporator to the exhaust outlet. Given the potential utilization of the heat from the exhaust gas flow, the third mode will typically only occur in the event of a heat pump malfunction.

[0027] According to another aspect of the invention, the use of a deflector in a hybrid heating appliance with a boiler and an air-to-water heat pump with a common supply air connection is proposed for the targeted division with predetermined proportions of an airflow from the supply air connection onto a first air path that passes by the boiler and a second air path that specifically flows around and cools the boiler.

[0028] The details, features, and advantageous designs discussed in connection with the hybrid heating appliance can also occur in the application presented here, and vice versa. In this respect, full reference is made to the explanations provided there for a more detailed characterization of the features.

[0029] It should be noted as a precaution that the numerical terms used here ("first", "second", etc.) primarily serve (only) to distinguish between several similar objects, quantities, or processes, and thus do not necessarily dictate any dependency and / or sequence between these objects, quantities, or processes. Should a dependency and / or sequence be required, this is explicitly stated here, or it will be obvious to a person skilled in the art upon studying the specific configuration described. Where a component can occur multiple times ("at least one"), the description of one of these components may apply equally to all or some of the multiple components, but this is not mandatory.

[0030] This document describes a hybrid heating unit and the use of a deflector, which at least partially solve the problems described with reference to the state of the art. In particular, the hybrid heating unit and its use contribute to providing a simple and compact hybrid heating unit that enables energy-efficient operation with low heat losses. Furthermore, the hybrid heating unit can be housed in a single enclosure, which can also be wall-mounted.

[0031] The invention and its technical context are explained in more detail below with reference to the accompanying figures. It should be noted that the invention is not intended to be limited by the exemplary embodiment shown. In particular, unless explicitly stated otherwise, it is also possible to extract aspects of the facts illustrated in the figures and combine them with other elements and findings from the present description. It should be emphasized that the figures, and especially the depicted dimensions, are only schematic. They show: Fig. 1: a hybrid heating device proposed here and Fig. 2: a deflector of the hybrid heating device.

[0032] Fig. 1 Figure 1 shows an exemplary and schematic representation of a proposed hybrid heating appliance 1. This appliance can comprise a boiler 3 and a heat pump 4, which are arranged in exactly one housing 2. The hybrid heating appliance 1, or rather its housing 2, has a front 38 and a back 39.

[0033] The heat pump 4 has a refrigeration circuit 15 in which a refrigerant can circulate and evaporate in an evaporator 8 and condense in a condenser 21. A compressor 9 and an expansion valve 16 can also be present in the refrigeration circuit 15, enabling pressure adjustment within the evaporator 8 and condenser 21. The components of the heat pump 4, or the heat pump 4 itself, are visibly arranged, particularly in the area of ​​the rear 39 of the housing 2. An exhaust gas duct 5 can be connected to the evaporator 8, through which a supply air flow and / or exhaust gas flow 22 passing through the evaporator can be fed to an exhaust gas connection 24 of the housing 2 and from there to a building's exhaust system. A first conveying device 7 can be arranged in or upstream of the exhaust gas duct 5, which draws a supply air flow and / or an exhaust gas flow 22 through the evaporator.

[0034] The boiler 3 can be configured to burn a fuel gas, such as natural gas or hydrogen. An exhaust gas stream 22 from the boiler 3 can be fed to the evaporator 8 via an exhaust gas inlet 34 and flow through it in a flow direction 32 of the evaporator 8. The boiler 3 can include a gas valve 36 and electronic components 37, such as a control and regulating unit. The components of the boiler 3 are particularly visible in the area of ​​the front 38 of the housing 2. Heat generated during the combustion of the fuel gas can be transferred via a heat exchanger 10 to a heat transfer fluid circulating in a heating circuit 20 by a circulation pump 17. The heating circuit 20 has a supply line 14 through which heated heat transfer fluid can be supplied to consumers such as radiators or underfloor heating systems, and a return line 11 through which the heat transfer fluid can be returned from the consumers.A hot water heat exchanger 35 is arranged between the flow 14 and return 11. This heat exchanger can heat a volume flow of potable or domestic hot water from a cold water connection 12 and supply it to a hot water outlet 13. For this purpose, heat transfer fluid from the flow 14 can be routed through the hot water heat exchanger 35 via a three-way valve 19. The boiler 3 includes a second pumping device 18 that can draw combustion air from the housing 2.

[0035] The housing 2 includes an air inlet 29 through which ambient air can be drawn in. A deflector 6 is arranged inside the housing 2, which directs the supply air flow 23 drawn in through the air inlet 29 past the boiler 3 via a first air path 25 as the first supply air flow 26, such that there is no or virtually no thermal contact between the first supply air flow 26 and the boiler 3. Therefore, no or only minimal heat is transferred from the outside of the boiler 3 to the first supply air flow 26.

[0036] The deflector 6 can further be configured to supply a second supply air stream 28 to a second air path 27, which is directed in such a way as to achieve targeted cooling of the boiler. The deflector 6 is configured to separate a predetermined second supply air stream 28, required for cooling the boiler 3, from the first supply air stream 26 and supply it to the second air path 27. This enables sufficient cooling of the boiler 3 while simultaneously limiting heat loss.

[0037] Furthermore, a third supply air stream 31 can be routed via a third air path 30. This third air path is arranged such that the third supply air stream 31 cools electronic components 37 and the gas valve 36, thus protecting them from overheating due to waste heat from the boiler 3. The second supply air stream 28 and the third supply air stream 31 are primarily initiated by the second conveying device 18, particularly when the boiler 3 is in operation.

[0038] Fig. 2 Figure 1 shows, by way of example and schematically, a deflector 8 configured for an air supply connection 29 that coaxially surrounds an exhaust gas connection 24. For this purpose, the deflector 8 has an annular area 33 that collects the air supply flow 23 from the air supply connection 29 and feeds it to the first air path 25. Reference symbol list

[0039] 1 Hybrid heating unit 2 Casing 3 Boiler 4 Heat pump 5 Flue gas duct 6 Deflector 7 First pumping unit 8 Evaporator 9 Compressor 10 Heat exchanger 11 Return 12 Cold water inlet 13 Hot water outlet 14 Flow 15 Refrigeration circuit 16 Expansion valve 17 Circulation pump 18 Second pumping unit 19 Three-way valve 20 Heating circuit 21 Condenser 22 Flue gas flow 23 Air intake flow 24 Flue gas connection 25 First air path 26 First air intake flow 27 Second air path 28 Second air intake flow 29 Air intake connection 30 Third air path 31 Third air intake flow 32 Flow direction evaporator 33 Annular area 34 Flue gas inlet 35 Hot water heat exchanger 36 Gas valve 37 Electronic components 38 Front 39 Back

Claims

1. Hybrid heating appliance (1) comprising a boiler (3) configured for the combustion of a fuel, and an air / water heat pump (4) with an evaporator (8), wherein the boiler (3) and the heat pump (4) are arranged within a common housing (2) and are configured to draw in a supply air flow (23) from a common supply air connection (29) and to direct an exhaust gas flow (22) from the boiler (3) to the evaporator (8) of the heat pump (4), wherein a deflector (6) is arranged and configured within the housing (2) such that the supply air flow (23) entering the housing (2) from the supply air connection (29) is guided past the boiler (3) on a first air path (25) in such a way that there is no thermal contact between the first air path (25) or the supply air flow (23) and the boiler (3), and then to the evaporator (8) and / or the is supplied to the boiler (3).

2. Hybrid heating device (1) according to claim 1, wherein the housing (2) of the hybrid heating device (1) has a front and a back, the back is designed for mounting the hybrid heating device (1) on a wall, and the first air passage (25) adjoins the back of the housing (2).

3. Hybrid heating appliance (1) according to one of the preceding claims, wherein a first conveying device (7) supplies air from the first air path (25) to the evaporator (8) of the heat pump (4), and a second conveying device (18) supplies air from the first air path (25) to the boiler (3) as combustion air.

4. Hybrid heating appliance (1) according to one of the preceding claims, wherein the deflector (6) is configured to divide the supply air flow (23) flowing from the supply air connection (29) into the housing (2) into the first air path (25) and a second air path (27), and a predetermined proportion of the supply air flow (23) on the second air path (27) flows around the boiler (3) for cooling.

5. Hybrid heating appliance (1) according to claim 4, wherein air is supplied to the boiler (3) via a third air path (30) from the first air path (25) to the boiler (3).

6. Hybrid heating appliance (1) according to claim 5, wherein the boiler (3) comprises a gas valve (36) and / or an electronic component (37) in the area of ​​the third air path (30), arranged such that the gas valve (36) and / or the electronic component (37) are cooled by the air flowing on the third air path (30).

7. Hybrid heating appliance (1) according to one of the preceding claims, wherein the boiler (3) is a condensing gas heating appliance.

8. Hybrid heating appliance (1) according to one of the preceding claims, wherein the air supply connection (29) is arranged coaxially to an exhaust gas connection (24).

9. Use of a deflector (8) in a hybrid heating appliance (1) with a boiler (3) and an air-to-water heat pump (4) with a common supply air connection (29) for targeted distribution with predetermined proportions of a supply air flow (23) from the supply air connection (29) onto a first air path (25) which passes by the boiler (3) and a second air path (27) which specifically flows around and cools the boiler (3).

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