HVAC equipment, method for operating an HVAC equipment, computer program and use of a ferrofluid

Abstract

A proposed HVAC device (1) comprises a refrigeration circuit (12) with a compressor (2), wherein the compressor (2) has a bearing within the HVAC device (1) that includes at least one damper (17, 18) containing a ferrofluid (22). This allows the damping constant of the damper (17, 18) to be set, thereby reducing the noise emissions and / or operating vibrations of the HVAC device (1). Furthermore, a method for operating the HVAC device (1), a computer program (13), and the use of a ferrofluid (22) are proposed.

Description

[0001] The invention relates to an HVAC device, a method for operating an HVAC device, a computer program and the use of a ferrofluid.

[0002] The term "HVAC" stands for "Heating, Ventilation and Air Conditioning," which refers to systems like heat pumps or air conditioners. These systems can be connected to a refrigeration cycle that transports heat using a refrigerant. The refrigerant evaporates in an evaporator of the refrigeration cycle, absorbing heat, and then condenses in a condenser, releasing the absorbed heat. Such HVAC systems often include an outdoor unit designed for heat exchange with an ambient medium, such as ambient air, geothermal energy, or groundwater. An indoor unit can be configured to transfer heat from the refrigeration cycle to a heat transfer circuit within the building, or vice versa, for cooling purposes.In addition, HVAC units, particularly heat pumps, are also known in monoblock design, in which the refrigeration circuit is located within a single unit, which is usually designed for installation outside a building. To create the necessary conditions for the phase transition of the refrigerant in the evaporator and condenser, the refrigeration circuit includes a compressor and an expansion valve. During operation, the compressor can generate significant vibrations, which cause noise emissions. These can be perceived as disturbing by people in the vicinity, especially with the increasing use of heat pumps for heating buildings. It is also known that prolonged exposure to noise can have adverse health effects.

[0003] Accordingly, there are efforts to minimize the noise emissions emanating from compressors of HVAC equipment.

[0004] For example, DE 11 2017 000 0915 T5 discloses a method for minimizing noise generated during the operation of an air conditioning system, in which interfering frequencies are detected by means of a vibration sensor or a microphone, and operating points with high noise emissions are avoided or quickly traversed by a processor. However, such a method disadvantageously limits the application range of the HVAC device.

[0005] Furthermore, it is known to use dampers to reduce vibration transmission from the compressor via its bearings. For example, dampers for air conditioning compressors containing a magnetorheological fluid are described in CN 114 151 497 A and CN 211 398 402 A. A disadvantage of magnetorheological fluids is their tendency to sediment due to particle size, necessitating regular mixing or the use of additives. Therefore, a proposed damper using a magnetorheological fluid is either not usable long-term or only with considerable effort.

[0006] 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, an HVAC device and a method for operating an HVAC device are to be proposed that enable a permanent and robust reduction of the noise emissions and operating vibrations occurring during operation, especially those caused by the compressor of the refrigeration circuit.

[0007] 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.

[0008] This is achieved by an HVAC unit that includes a refrigeration circuit with a compressor and in which the compressor has a bearing in the HVAC unit that contains at least one damper and a ferrofluid.

[0009] An HVAC system can be designed, for example, to change the temperature and / or humidity of a building or of one or more rooms within a building. An HVAC system is a device and / or component, or a combination thereof, that can provide the user with a solution tailored to one or more of the following tasks: • Heating • Ventilation • Air conditioning (cooling) • Hot water preparation • Electricity production • Energy management.

[0010] The HVAC unit preferably includes a heat pump. The heat pump is designed to extract heat from an ambient medium, such as ambient air, the ground, or groundwater, and make it available for use. For this purpose, the heat pump may include a refrigeration cycle. The refrigeration cycle circulates a refrigerant that undergoes a phase change in a compressor and a condenser to transfer heat. To control the phase change, the refrigeration cycle also includes a compressor and an expansion valve. The heat pump may have an indoor unit located inside the building being served and an outdoor unit located outside the building. Alternatively, the heat pump may also be a monobloc unit. The heat pump can also be an air conditioner that can operate a refrigeration cycle to cool a room or building.

[0011] The HVAC unit can be a modulating unit, adjusting its output, particularly continuously, to meet heating or cooling demands. Depending on the output, a mechanical device or component, such as one or more fans in the outdoor unit of a heat pump for heat exchange with ambient air, and / or a compressor in the refrigeration circuit of a heat pump, etc., is typically operated at different speeds. Operating at varying output levels can indicate different operating states or points.

[0012] The compressor in question is specifically a compressor of a refrigeration circuit within an HVAC unit, designed to compress the refrigerant. For this purpose, the compressor has a compressor mechanism driven by an electric motor. During operation, both the compressor mechanism and the electric motor can generate mechanical vibrations. At least one bearing is arranged between the compressor and the HVAC unit, for example, a support within the HVAC unit, to prevent the transmission of vibrations occurring at the compressor through the bearing. This bearing includes at least one damper containing a ferrofluid. The bearing is located within the HVAC unit, which in other words means, in particular, that the bearing is located within a housing of the HVAC unit.The HVAC unit can have exactly one housing in which the compressor of the refrigeration circuit and the compressor's bearings are located.

[0013] A ferrofluid is a liquid consisting of small magnetic particles, typically 5 to 10 nanometers in size, colloidally suspended in a carrier fluid. The particles can be made of materials such as iron, magnetite, or cobalt and are smaller than the magnetic domain (Weiss region) of the material. The carrier fluid can be, in particular, an oil. n-Decane or heptane have proven to be suitable carrier fluids, and suitable nanoparticles can be ferrites or cobalt-substituted magnetite ferrofluids (Co₂). x Fe 1-x Fe2O4), magnetite (e.g. Fe2O4), garnets (substances from the garnet group), or also y-Fe2O3, Fe2O3, Fe3O4, CoFe2O4 and / or NiFe2O4.

[0014] According to one embodiment, the at least one damper of the bearing can include a device for generating a variable magnetic field. The device for generating a variable magnetic field is thus configured to generate a magnetic field in a region where the ferrofluid is arranged, wherein the magnetic field strength can be adjusted by controlling the device for generating the magnetic field. The device for generating the magnetic field can include at least one electromagnet. The magnetic field generated by the device for generating the variable magnetic field acts on the particles of the ferrofluid, thereby changing the damping constant of the damper. This allows the damper to be adjusted to different frequencies and amplitudes of compressor oscillations.The adjustment can consist of the strength of the magnetic field generated by the device for generating a variable magnetic field. A change in the magnetic field can be achieved, in particular, by changing the current flow in an electromagnet used as a device for generating a variable magnetic field.

[0015] The assembly can comprise at least one damper; in particular, it can comprise three or four dampers containing a ferrofluid and a device for generating a variable magnetic field. The assembly can also comprise multiple damper stages, in particular damper stages arranged in series.

[0016] According to one embodiment, the compressor can be mounted on a bearing element by means of at least one first damper containing a ferrofluid and a device for generating a variable magnetic field, and the bearing element can be mounted on or in the HVAC unit by means of at least one second damper, also containing a ferrofluid and a device for generating a variable magnetic field. The bearing element can be a support plate or the like. Other components, such as a liquid separator, the condenser, and / or piping of the refrigeration circuit, can also be arranged on the support plate. Preferably, three or four first dampers and three or four second dampers are provided.Therefore, the at least one first damper could be understood as the first damping stage and the at least one second damper as the second damping stage, with the first and second damping stages connected in series. In this sense, the first and second damping stages can also be understood as a vibration system, with the first and second damping stages influencing each other.

[0017] According to one embodiment, the at least one damper can comprise a cylinder containing the ferrofluid, in which at least one piston is movably mounted. The cylinder has a surface around which a winding of a coil for generating an electromagnetic field is arranged. In this respect, the cylinder and the at least one piston are located in the region of the core of the coil for generating the electromagnetic field. It is understood that several dampers can also be used in parallel or in series.

[0018] According to a further aspect of the invention, a method for operating an HVAC device is proposed in which an operating point of the HVAC device and / or an operating point of one or more components of the HVAC device is assigned a setting of the device for generating a variable magnetic field of the at least one damper and is stored in a characteristic curve or in a characteristic map, and when an operating point of the HVAC device and / or one or more components is reached, the setting of the device for generating a variable magnetic field assigned to the corresponding characteristic curve or characteristic map is set.

[0019] The method can be performed continuously and permanently during operation of the HVAC equipment. It serves to reduce the noise emissions of the HVAC equipment and can therefore also be understood as a method for reducing the operating noise of an HVAC device. The method can be executed fully automatically by a control unit of the HVAC equipment. For this purpose, the control unit can be connected electronically to at least one device for generating a variable magnetic field. "Electronically" here means that the strength of the magnetic field can be adjusted by the device performing the method, in particular the control unit of the HVAC equipment.

[0020] The characteristic curve or map thus assigns a strength of the magnetic field of at least one first and / or second damper to an operating point of the HVAC device and / or one of its components, in particular the compressor, and can, for example, be stored in the memory of a computer performing the process. The characteristic curve or map may have been determined in advance for the at least one damper during tests on a reference HVAC device.

[0021] According to one embodiment, the HVAC device can include a vibration detection device that, during operation, detects the noise emissions of the HVAC device and allows the HVAC device and / or its components to be operated in such a way as to minimize the detected noise emissions. One component of the HVAC device can be, in particular, a compressor. Thus, the settings of the at least one device for generating a variable magnetic field can be optimized with regard to the noise emissions, for example, within the framework of a control system.

[0022] One or more vibration detection devices may be provided. In particular, a device may be provided for detecting the vibrations of the first damping stage and a second damping stage and / or further damping stages. The vibration detection device may be any type of vibration sensor, in particular a microphone or an accelerometer.

[0023] According to one design, the characteristic map and / or curve can be adapted based on the recorded vibrations. This allows changes in vibration behavior to be detected and the characteristic curve and / or map to be adjusted accordingly. This can be done using a machine learning algorithm. Artificial intelligence can also be used to analyze the recorded vibrations and adjust the characteristic curve or map accordingly.

[0024] According to one embodiment, the HVAC device can include a control unit configured to regulate and control the refrigeration circuit of the HVAC device and to execute a procedure proposed herein. For this purpose, the control unit can, for example, include and / or have a processor. In this context, the processor can, for example, execute the procedure stored in a memory (of the control unit). Advantageously, parameters, such as one or more characteristic curves or maps, can also be stored in the memory of the control unit.

[0025] According to another aspect, a computer program product is also proposed, which is configured to carry out a procedure presented here. In other words, this specifically concerns a computer program (product) comprising instructions that, when executed by a computer, cause it to execute a procedure proposed here. According to a further aspect, a machine-readable storage medium on which the computer program is stored is also proposed. The machine-readable storage medium is typically a computer-readable data carrier.

[0026] Another aspect proposes the use of a ferrofluid to adjust the damping characteristics of at least one damper in a compressor of an HVAC unit. For this purpose, the compressor can be mounted on or within the HVAC unit on a bearing that includes at least one damper. The damper can incorporate a device for generating a variable magnetic field to alter its damping characteristics, particularly its damping constant. Multiple damping levels can also be provided.

[0027] The details, features, and designs discussed in connection with the HVAC device can also occur in the method, computer program, and use proposed here, and vice versa. In this respect, the features relating to the HVAC device can also be used to characterize the method, the computer program, and the use, and vice versa.

[0028] 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.

[0029] This document describes an HVAC device, a method for operating an HVAC device, a computer program, and the use of a ferrofluid, which at least partially solve the problems described with reference to the prior art. In particular, the HVAC device, the method, the computer program, and the use contribute significantly to reducing the noise emissions of an HVAC device. The use of a ferrofluid in the at least one damper enables particularly long-term stable and precise damping, especially since a ferrofluid does not tend to sediment. The method allows the damping of the at least one damper to be adjusted to changes in vibration behavior, for example, caused by component wear or the accumulation of foreign substances.

[0030] Furthermore, the invention is very well suited for retrofitting existing heating devices and can often be achieved by simply replacing the dampers of a compressor in an HVAC device.

[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 embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the situations described in the figures and combine them with other components 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: one HVAC device suggested here, Fig. 2: a sectional view of an HVAC device proposed here, and Fig. 3: a damper suggested here.

[0032] Fig. Figure 1 shows an exemplary and schematic representation of an HVAC unit 1 presented here, implemented as a heat pump for supplying a building 7 with thermal energy. The HVAC unit 1 can comprise an outdoor unit 6, which extracts heat from the ambient air, and an indoor unit 8 for transferring the absorbed heat into the building 7. A refrigerant can be circulated in a refrigeration circuit 12, which can evaporate in an evaporator 3 of the refrigeration circuit 12 and liquefy in a condenser 4 of the refrigeration circuit 12. Furthermore, a compressor 2 (also referred to as a compressor unit) and an expansion valve 5 can be provided in the refrigeration circuit 12, with the compressor 2 being driven by an electric motor. The expansion valve 5 can have an adjustable opening width, which can be controlled by a motor, for example, a stepper motor.The refrigerant can be transported in the refrigeration circuit 12 in a flow direction 11 from the evaporator 3 via the compressor 2 to the condenser 4 and further via the expansion valve 5 back to the evaporator 3.

[0033] The HVAC unit 1 includes a control unit 10, configured to regulate and control the operation of the refrigeration circuit 12. The control unit 10 is also configured to execute a procedure proposed herein. For this purpose, a computer program 13, which causes the control unit 10 to execute a procedure proposed herein, may be stored in a memory of the control unit 10.

[0034] Fig. Figure 2 shows an exemplary and schematic cross-sectional view of an HVAC unit 1 presented here. The HVAC unit 1 includes at least one fan 15, which is configured to supply ambient air 14 to the heat exchanger 9. The compressor 2 is mounted on a support element 16 by means of four first dampers 17. The support element 16 is mounted relative to the HVAC unit 1, for example, a support for the housing of the HVAC unit 1, by means of four second dampers 18. The first dampers 17 can be considered the first damping stage and the second dampers 18 the second damping stage. The HVAC unit 1 also includes mounting dampers 19, which dampen the HVAC unit 1 relative to a foundation or the ground at the installation site. The mounting dampers 19 can also be filled with a ferrofluid 22 and include a device for generating a variable magnetic field, and can thus be considered a third damping stage.The HVAC device 1 also includes a first vibration detection device 27, which detects vibrations of the bearing element 16 and thus of the first damping stage, and a second vibration detection device 28, which detects vibrations of the support of the bearing element 16 and thus of the second damping stage.

[0035] Fig.Figure 3 shows an exemplary and schematic cross-sectional view of a first damper 17 and / or second damper 18. This damper comprises a cylinder 25 filled with a ferrofluid 22. A first piston 23 and a second piston 24 are movably arranged within the cylinder 25 in the direction of a set vibration amplitude 26. Windings 20 of a coil 21 are arranged around a surface of the cylinder 25 to generate a variable magnetic field, such that a current flow in the windings 20 of the coil 21 generates a magnetic field in the region of the cylinder 25 and thus of the ferrofluid 22.

[0036] According to a method proposed here, the control unit 10 can detect an operating point of the HVAC device 1 and assign a setting to be made to the first dampers 17 and / or second dampers 18 based on a characteristic curve or map stored in the memory of the control unit 10. This setting can be implemented by the control unit 10 by adjusting the current flow in the coils 21 of the first dampers 17 and / or in the coils 21 of the second dampers 18. The current flow in a coil 21 of a damper 17, 18 causes a change in the magnetic field generated by the coil 21, and thus a change in the viscosity of the ferrofluid 22. This change in the viscosity of the ferrofluid 22 causes a change in the damping constant of the damper 17, 18.

[0037] According to one embodiment of the method, the control unit 10 can use signals from the first vibration detection device 27 and / or the second vibration detection device 28 to optimize the settings of the dampers 17, 18. According to a further embodiment, the control unit 10 can be configured to adapt the characteristic curve or map to a change in vibration behavior detected by one or more vibration detection devices 27, 28.

[0038] The procedure can be carried out continuously or permanently during the operation of HVAC device 1. Reference symbol list 1 HVAC unit 2 compressor 3 evaporators 4 liquefiers 5 Expansion valve 6 Outdoor part 7 buildings 8 Inner part 9 heat exchangers 10 Control and monitoring unit 11 Flow direction 12 Refrigeration cycle 13 Computer program product 14 Ambient air 15 blowers 16 bearing element 17 first dampers 18 second dampers 19 dampers 20 windings 21 coil 22 Ferrofluid 23 first piston 24 second piston 25 cylinders 26 Vibration amplitude 27 first device for detecting vibrations 28 second device for detecting vibrations QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 11 2017 000 0915 T5

[0004] CN 114 151 497 A

[0005] CN 211 398 402 A

[0005]

Claims

[1] HVAC device (1) comprising a refrigeration circuit (12) with a compressor (2), wherein the compressor (2) has a bearing in the HVAC device (1) comprising at least one damper (17, 18) containing a ferrofluid (22). [2] HVAC device (1) according to claim 1, wherein the at least one damper (17, 28) comprises a device for generating a variable magnetic field. [3] HVAC device (1) according to any of the preceding claims, wherein the HVAC device (1) comprises a heat pump. [4] HVAC device (1) according to one of the preceding claims, wherein the at least one damper (17,18) comprises a cylinder (25) containing the ferrofluid (22) and in which at least one piston (23, 24) is movably mounted, wherein the cylinder (25) has a lateral surface around which a winding (20) of a coil (21) for generating an electromagnetic field is arranged. [5] HVAC device (1) according to one of the preceding claims, wherein the compressor (2) is mounted on a bearing element (16) by means of at least one first damper (17) and the bearing element (16) is mounted on the HVAC device (1) by means of at least one second damper (18). [6] HVAC device (1) according to any one of claims 2 to 5, wherein the HVAC device (1) comprises a control and regulating device (10) which is connected to the device for generating a variable magnetic field via data technology. [7] Method for operating an HVAC device (1) according to claim 6, wherein at an operating point of the HVAC device (1) and / or an operating point of one or more components of the HVAC device (1) a setting of the device for generating a variable magnetic field is assigned and stored in a characteristic curve or in a characteristic map, and when an operating point of the HVAC device (1) and / or one or more components is reached, the assigned setting of the device for generating a variable magnetic field is set. [8] Method according to claim 7, wherein the HVAC device (1) comprises a vibration detection device (27, 28) which detects the noise emissions and / or vibrations of the HVAC device (1) during operation and operates the HVAC device (1) and / or components thereof in such a way as to reduce the detected noise emissions. [9] Method according to claim 8, wherein the characteristic curve or map is adapted based on a signal from the vibration detection device (27, 28). [10] Computer program product (13) comprising commands that cause an HVAC device (1) according to claim 6 to execute a method according to any one of claims 7 to 9. [11] Use of a ferrofluid (22) to adjust the damping properties of a damper (17, 18) of a compressor (2) of an HVAC device (1).

Images