Fan ring nozzle and heat pump

Abstract

The invention relates to a fan ring nozzle (20) for a fan (14), in particular of an evaporator (20), comprising a hollow cylindrical nozzle body (22) made of plastic and an electric heating element (24). The heating element (24) is integrated into the nozzle body (22). The invention further relates to a heat pump (2).

Description

[0001] The invention relates to a fan ring nozzle for a fan, comprising a hollow cylindrical nozzle body made of plastic. The invention also relates to a heat pump with a fan that includes a fan ring nozzle.

[0002] Heat pumps are increasingly being used for heating buildings. These systems have a refrigerant circuit with a compressor driven by an electric motor. The compressor compresses a gaseous refrigerant, usually supplied through pipes, which is then fed to a first heat exchanger. This heat exchanger is, for example, thermally connected to another component of the heating system. Heat energy is extracted from the refrigerant there, causing it to cool and liquefy. The liquefied refrigerant is then directed to an expansion valve, which reduces the pressure, causing some of the liquid refrigerant to evaporate. The cooled refrigerant is then fed to a second heat exchanger, also known as an evaporator, which, in the case of an air-to-water heat pump, is typically exposed to ambient air.Heat is extracted from the surroundings and used to reheat the refrigerant. The refrigerant is then returned to the compressor.

[0003] To enable the evaporator to transfer a relatively large amount of energy, it is usually designed with a relatively large surface area. The evaporator is also typically located outside the building, ensuring a relatively high flow of ambient air through it. This improves the transfer of energy from the ambient air to the refrigerant within the evaporator. To assist this airflow, a fan is usually present, featuring a fan wheel driven by a separate electric motor. To properly direct the airflow generated by the fan wheel, a fan ring nozzle is typically used. This nozzle usually surrounds the fan wheel on the outside and is attached to the evaporator.

[0004] At relatively low ambient temperatures, condensation can form on the evaporator, which has cooled down due to operation, and consequently also in the area of ​​the fan ring nozzle. This water can freeze at low ambient temperatures, especially below 0°C, which can cause the fan impeller to freeze to the fan ring nozzle. Subsequent operation is then prevented, preventing airflow and thus impairing energy exchange via the evaporator, thereby reducing the heat pump's efficiency. Since this occurs primarily at relatively low ambient temperatures, it is even possible that the building will no longer be adequately heated. Even if the fan impeller does not freeze, it is possible that it will scrape against the ice during operation, leading to damage or at least unwanted noise.

[0005] To remedy this, a heating element is typically attached to the outer side of the fan ring nozzle, facing away from the fan wheel. If the fan wheel is detected freezing to the fan ring nozzle, or before each start of the electric motor associated with the fan wheel, the heating element is energized, thus warming the fan ring nozzle. As a result, any ice that may have accumulated there is melted, and the fan wheel is released again if necessary. In a further development, the heating element is energized under certain critical operating conditions and / or operated according to a characteristic curve in such a way that freezing of the fan wheel cannot occur.

[0006] The heating element is typically ribbon-shaped and wrapped around the hollow cylindrical fan ring nozzle, which is designed as a rotationally symmetrical hollow body. The two ends of the heating element are connected by a spring, ensuring a positive fit between the heating element and the fan ring nozzle. This guarantees secure contact between the heating element and the outside of the fan ring nozzle. Even if, for example, the heating element is slightly separated from the fan ring nozzle due to a loss of spring elasticity, the operation of the heat pump is not affected. However, the area between the two ends of the heating element, where the spring is located, remains unheated. Therefore, a relatively high energy input into the fan ring nozzle is required to reliably melt any ice adhering to it.

[0007] The invention is based on the objective of providing a particularly suitable fan ring nozzle for a fan and a particularly suitable heat pump, wherein assembly is expediently facilitated and / or a load is reduced, and wherein energy requirements are preferably reduced.

[0008] With regard to the fan ring nozzle, this problem is solved according to the invention by the features of claim 1, and with regard to the heat pump by the features of claim 10. Advantageous further developments and embodiments are the subject of the respective dependent claims.

[0009] The fan ring nozzle is for a fan. In other words, the fan ring nozzle is particularly suitable, and preferably designed and configured, to form a component of the fan. The fan is suitably designed with an electric motor and preferably includes an electric motor. Furthermore, the fan has a fan wheel, which is driven, in particular, by the electric motor. When the electric motor is operating, the fan wheel is rotated about an axis of rotation, which expediently corresponds to the axis of rotation of the electric motor. Suitably, the fan wheel is directly connected and attached to the electric motor, which increases compactness.

[0010] The fan wheel is preferably an axial fan wheel. Advantageously, the fan wheel has a hub to which the electric motor is attached. The hub is preferably arranged on the axis of rotation. Several fan blades are suitably arranged on the radial outer side of the hub, extending at least partially radially outwards with respect to the axis of rotation. For example, the radially outer ends of the fan blades are straight, or they may be bent. Alternatively, an outer ring is attached to them, which is preferably arranged concentrically to the axis of rotation. The outer ring suitably stabilizes the fan blades relative to each other.

[0011] The fan ring nozzle has a hollow cylindrical nozzle body. Consequently, the nozzle body has a cylindrical axis along which it extends. Preferably, the nozzle body is provided essentially by means of a wall. The thickness of the wall is, for example, between 0.5 mm and 1 cm or between 1 mm and 5 mm. The wall thickness is, for example, essentially 3 mm. The wall is bounded, in particular, by a radial inner surface and a radial outer surface.

[0012] Advantageously, in the assembled state, the nozzle body is arranged concentrically to the axis of rotation of the fan wheel, so that the axis of rotation corresponds to the cylinder axis. In this configuration, the fan wheel is circumferentially surrounded by the nozzle body, with any fan blades, for example, spaced apart from the inside of the nozzle body. Alternatively, the outer ring, for example, engages with a corresponding structure of the fan ring nozzle, thus preventing the formation of leakage air. Alternatively, another type of seal, such as a brush seal, is arranged between the outer ring and the inside of the nozzle body.

[0013] The nozzle body is suitable, and in particular designed and configured, to shape and / or direct the resulting airflow when the fan wheel arranged within it rotates. For example, the nozzle body has a substantially uniform cross-section perpendicular to the cylinder axis along its entire length. Alternatively, this cross-section is variable, and in particular continuously enlarged in the axial direction parallel to the cylinder / rotation axis, so that the nozzle body is widened, especially on one discharge side. This also enables the intake of a comparatively large volume of air, while reducing the formation of undesirable turbulence on the discharge side.

[0014] The nozzle body is made of a plastic. In other words, the nozzle body consists of the plastic. For example, polypropylene (PP) or acrylonitrile butadiene styrene copolymer (ABS) is used as the plastic. Fiber-reinforced plastic, for example with glass fibers, is particularly preferred. Specifically, PP G40 is used as the plastic. The nozzle body is manufactured using a plastic injection molding process. This reduces manufacturing costs.

[0015] The fan ring nozzle further comprises an electric heating element, also referred to simply as the heating element. The electric heating element is designed such that it heats up when energized, particularly when an electrical voltage is applied, and heat is advantageously transferred to the surroundings of the heating element, preferably into the nozzle body. For this purpose, the electric heating element has two connections. For example, the heating element comprises one or more Peltier elements or, advantageously, ohmic resistors. Alternatively or in combination, the heating element is designed such that heating occurs due to an applied electrical resistance. In summary, the heating element advantageously has no moving parts.

[0016] The heating element is integrated into the nozzle body. In other words, the heating element is permanently connected to the nozzle body, and these are designed as a single unit. In summary, the heating element and the nozzle body appropriately form a single assembly. Consequently, removing the heating element from the nozzle body is not possible, at least not without damaging it. Alternatively, or in combination with this, it is not possible to clearly distinguish which individual areas / components of the fan ring nozzle belong to the heating element and which belong to the nozzle body. In other words, individual components of the assembly cannot be assigned solely or exclusively to the heating element and / or the nozzle body.

[0017] In particular, the heating element is designed such that when current is applied, the nozzle body is heated, preferably at least on its inner side. This releases the fan wheel if it is frozen in place, allowing it to rotate freely. The heating element is particularly suitable, expediently designed, and configured for this purpose. Alternatively or in combination with this, the heating element is suitable, expediently designed, and configured to prevent the fan wheel from freezing, for which purpose it is also supplied with a suitable current.

[0018] Consequently, separate mounting of the heating element and the fan ring nozzle to other fan components is unnecessary, thus simplifying assembly. Furthermore, the heating element cannot detach from the fan ring nozzle, preventing detachment even under relatively high loads and / or extended use, which could, for example, lead to a blockage of the fan wheel surrounded by the fan ring nozzle. The integration also improves heat transfer between the heating element and the nozzle body, preventing or at least reducing heat loss in unwanted directions. This reduces the energy required to heat the fan ring nozzle. The necessary local heating is comparatively low to heat the nozzle body evenly to a relatively high temperature.In other words, localized excessive heating of the nozzle body, which can lead to embrittlement of the plastic and thus to premature aging, is avoided. Consequently, the service life of the fan ring nozzle is extended, and aging effects are reduced.

[0019] Due to the integration of the heating element into the nozzle body, it is also possible to selectively heat specific areas of the nozzle body where, for example, ice formation is most prevalent. This allows for targeted heat application to critical areas, while other parts of the nozzle body, where ice formation is minimal or nonexistent, are heated to a lesser degree. This results in more efficient operation and reduced energy consumption.

[0020] Furthermore, the design as a single unit improves the visual appearance, thus increasing user acceptance. In particular, the integration also provides a comparatively smooth inner and outer surface for the fan ring nozzle, preventing the adhesion of foreign particles. This also simplifies cleaning.

[0021] The fan, which includes the fan ring nozzle, is advantageously a component of an evaporator. The evaporator is, in particular, a heat exchanger. The evaporator is advantageously a component of a heat pump, for example, an outdoor unit of the heat pump. The heat pump serves, for example, for cooling and, when installed, is particularly a component of an air conditioning system. Preferably, however, the heat pump is a component of a heating system. The heat pump serves, in particular, to heat a building, for example, a single-family home, an apartment building, or a factory building. In particular, the heat pump has a nominal heating output between 2.6 kW and 15 kW or up to 60 kW. The heat pump is particularly suitable, advantageously designed, and configured for this purpose. In particular, the heat pump is a so-called air-to-water heat pump.

[0022] The heat pump preferably comprises a compressor driven by an associated electric motor. The electric motor is, in particular, a brushless direct current (BLDC) motor. The compressor suitably serves to compress a refrigerant in the heat pump's refrigerant circuit. The compressor, for example, the compressor head, is expediently connected to a heat exchanger via a fluid connection, particularly by means of a pipe. For example, the heat exchanger is either an integral part of the heat pump or separate from it. The heat exchanger is expediently connected to an expansion valve via a fluid connection, which in turn is preferably connected to an evaporator, which also forms a heat exchanger. This evaporator is connected to the compressor, thus creating a refrigerant circuit. In particular, the refrigerant circuit is filled with a refrigerant.

[0023] For example, only the heating element is integrated into the nozzle body. Preferably, the connections of the heating element are led out of the nozzle body so that suitable current can be supplied. Advantageously, the connections exit the nozzle body on its radial outer side so that the operation of the fan wheel is not affected. This also allows for subsequent electrical contacting, especially after the fan wheel has already been mounted.

[0024] In a further development, electronics are integrated into the nozzle body, primarily for controlling the power supply to the electric heating element. For example, the electronics regulate or at least adjust the current to the heating element according to specific requirements. In this design, the heating element's connections are fully integrated into the nozzle body and electrically connected to the electronics. The electronics also have additional connections that extend from the nozzle body, preferably on the radial outer surface. Thanks to the electronics, a modular unit is provided, and the operation of the fan ring nozzle, particularly the heating element, requires only a connection to a power supply, with operation being entirely controlled by the electronics integrated into the nozzle body.This further simplifies installation, and, for example, makes it possible to retrofit an existing heat pump or similar device with such a fan ring nozzle.

[0025] For example, a temperature sensor or similar device is also assigned to the nozzle body and preferably integrated into it. The temperature sensor is preferably connected to the electronics via a signal connection. In this case, for example, the heating element is energized depending on the temperature measured by the temperature sensor.

[0026] For example, the nozzle body has one or more cavities or the like into which the heating element is inserted. This allows, in particular, for the nozzle body to be manufactured independently of the heating element. Preferably, however, the heating element is embedded in the plastic. In other words, this creates a material-bonded connection between the heating element and the plastic. Alternatively, or preferably in combination with this, they are also positively connected. As a result, a comparatively robust attachment of the heating element to the plastic is achieved. For example, the plastic is locally deformed for embedding, for which it is temporarily liquefied or converted into a paste-like state. Preferably, however, the embedding of the heating element takes place in a single step with the manufacture of the nozzle body.The nozzle body is suitably manufactured using a plastic injection molding process, and the plastic is injected onto the heating element. This injection molding process creates a material-bonded and form-fitting connection between the heating element and the nozzle body, resulting in a robust assembly.

[0027] For example, the heating element formed at least a portion of the surface of the fan ring nozzle or at least of the assembly provided by the nozzle body and the heating element. In particular, a groove or recess on the inside of the nozzle body is filled by the heating element. This allows for visual inspection of the heating element. Furthermore, it enables relatively effective heating of the fan wheel located in the fan ring nozzle.

[0028] However, the heating element is particularly advantageous when it is overmolded with plastic. Consequently, the heating element is essentially invisible and completely surrounded by the plastic. The plastic thus serves primarily as electrical insulation, which is why the insulation requirements for the heating element itself are comparatively low. This reduces manufacturing costs. Furthermore, this design prevents mechanical damage to the heating element should, for example, foreign matter be drawn in through the fan ring nozzle. This increases its robustness. Damage to the heating element during the installation of the fan ring nozzle on other components of the heat pump or during the installation of the fan wheel is also prevented. For example, the heating element is positioned essentially centrally within the wall formed by the nozzle body.However, it is more practical to position the heating element closer to the inside, so that the fan wheel is heated more efficiently.

[0029] Preferably, the heating element is designed in a ribbon shape. This makes it particularly flexible and allows for increased extension in one direction. Consequently, storage, suitable positioning, and / or attachment to the plastic are facilitated, thus simplifying the production of the fan ring nozzle. The heating element advantageously has a path extending at least tangentially. The tangential direction is defined here, in particular, by the cylinder axis. Due to the tangential path, it is possible to heat a larger area along which the fan blades are guided. Advantageously, the heating element is arranged such that it overlaps the fan wheel, at least partially, in the axial direction (i.e., parallel to the cylinder axis) when assembled, and thus covers it.Consequently, a relatively precise heat input into the fan wheel and any ice located between them is possible.

[0030] Preferably, the heating element is guided once around the cylinder axis. This makes it possible to heat the entire circumference of the fan wheel using the heating element. It also ensures that any frozen fan wheel is released when the heating element is energized. For example, the heating element is designed to describe a 360° circle. This results in a comparatively small amount of material being required. However, it is particularly preferred that the heating element overlaps in the tangential direction. Consequently, a larger angle than 360° is achieved using the heating element, with, for example, the overlapping ends being spaced apart radially. Due to the overlap, the length of the heating element is increased, and there are no areas in the tangential direction that are not heated or are only heated minimally when the heating element is energized.This ensures that any ice present is melted, while requiring comparatively little energy. This also prevents localized excessive heating of the nozzle body.

[0031] For example, the overlapping ends are simply offset radially outwards. However, the heating element is particularly preferably arranged in a helical shape, i.e., both tangentially and axially. In this way, a comparatively large area of ​​the nozzle body is penetrated by the heating element and heated when the heating element is in operation, leading to a relatively rapid melting of any ice that may be present. It is also possible to choose a relatively narrow or small diameter for the heating element, which simplifies storage and manufacturing of the fan ring nozzle. Alternatively, or in combination with this, the heating element is laid out in a meandering pattern, at least in sections. This also makes it possible to penetrate a large area of ​​the nozzle body with the heating element.

[0032] For example, the heating element is a separate component that is inserted into and / or attached to the plastic or a cavity formed by the plastic to manufacture the fan ring nozzle. In other words, a clear distinction between the plastic and the heating element is possible. The heating element is, for example, designed as a graphite strip.

[0033] In another alternative, the heating element is at least partially integrated with the nozzle body. In other words, the heating element is at least partially formed by the plastic of the nozzle body. Thus, the boundaries between the heating element and the nozzle body are not clearly defined. In summary, the nozzle body at least partially forms the heating element, and they are at least partially made of the same material.

[0034] Thus, the heating element is at least partially formed using plastic. Consequently, the number of different materials and the number of required manufacturing steps for the fan ring nozzle are reduced, which lowers production costs. Furthermore, the development of mechanical stresses during heating is avoided, as essentially only a coefficient of thermal expansion is present.

[0035] Advantageously, the heating element comprises two (electrical) conductors. These two conductors are, for example, guided through the nozzle body (i.e., the plastic) or at least in contact with it, preferably directly. The two conductors are spaced apart from each other so that, in particular, there is no direct mechanical contact. The two conductors are, in particular, at least partially, and preferably completely, uninsulated. For example, the two conductors are made of the same material or of different materials. Preferably, the conductors are made of aluminum (i.e., pure aluminum or an aluminum alloy), copper (i.e., pure copper or a copper alloy), graphite, or iron. Advantageously, the conductors are provided by means of an uninsulated wire or a wire that is at least partially uninsulated. This reduces manufacturing costs.

[0036] The plastic between the conductors is electrically conductive. In other words, the nozzle body is electrically conductive in the area between the two conductors. Thus, the two conductors are electrically connected to each other via the electrically conductive plastic, preferably directly. Consequently, an electric current flow (current absorption) between the two conductors is possible through the plastic. In particular, the areas of the fan ring nozzle to be heated are defined by the arrangement of the electrical conductors and / or the plastic.

[0037] Due to this design, only the two conductors and the plastic are required to manufacture the fan ring nozzle, thus reducing production costs. It is also possible to route the two conductors with relative flexibility, enabling targeted heating of specific areas of the nozzle body. For example, the conductors can be arranged axially offset from each other and run in a helical pattern. Alternatively, the conductors can be radially offset from each other.

[0038] The plastic is specifically designed to have a comparatively high (electrical / ohmic) resistance. When an electrical voltage is applied to the two conductors, i.e., when the heating element is energized, the electrically conductive plastic is heated, and this plastic forms at least part of the nozzle body.

[0039] Advantageously, the two conductors are mechanically connected to each other by means of the electrically conductive plastic, preferably directly. Suitablely, the conductors are overmolded with the (electrically conductive) plastic, which simplifies manufacturing.

[0040] To provide electrical conductivity, the plastic, for example polypropylene or ABS, is mixed with carbon. For instance, only part of the nozzle body is made of the electrically conductive plastic, while other components are made of a different plastic or have reduced electrical conductivity. This prevents unintentional short circuits with other components. In one such case, the nozzle body is made of a two-component plastic. Alternatively, the entire nozzle body is electrically conductive, simplifying manufacturing. Another alternative uses conductive ink to provide electrical conductivity.

[0041] In this advanced training, the electrical resistance of the plastic is temperature-dependent, and the assembly thus provides a type of PTC element. In other words, a plastic with temperature-dependent electrical resistance is used. Consequently, the temperature of the fan ring nozzle can be determined from the electrical current flowing through the heating element when a specific voltage is applied, eliminating the need for an additional temperature sensor. When the temperature is sufficiently high to prevent icing, the electrical resistance is so high that essentially no current flows. Conversely, as the temperature drops, the electrical resistance decreases, and an electrical current flows, leading to the heating of the nozzle body. This enables a self-regulating electrical circuit.Alternatively, the temperature can be determined in a different operating mode in which, in particular, no heat is introduced into the nozzle body by means of the heating element.

[0042] In summary, the current draw of the heating element is limited by the material due to its temperature-dependent electrical resistance. This eliminates the need for a separate temperature control. Specifically, the plastic is selected such that current is only drawn at temperatures where icing is theoretically possible, meaning the electrical current flows between the conductors through the plastic. At higher temperatures, there is essentially no current draw. For example, the plastic material is chosen such that current draw occurs at temperatures between 0°C and 10°C, or between 2°C and 7°C, and essentially at 5°C. During operation, and particularly during continuous operation, an electrical voltage is conveniently applied to the conductors.However, the (electrical) current only flows if icing occurs or can occur.

[0043] Furthermore, the icing state of the fan ring nozzle can be determined based on the electrical resistance / current consumption. Preferably, the plastic is selected such that the time of defrosting can be determined. In particular, the plastic is selected such that, when icing is present, the current consumption is essentially constant, or at least greater than a certain limit. In other words, a performance plateau exists when icing is present. When defrosting is complete, the performance plateau is preferably followed by a, in particular rapid, drop in performance, i.e., a drop in the conducted electrical current, even if the applied electrical voltage is constant. No performance plateau exists, and in particular, the current consumption is lower than a further limit, which is suitably comparatively low, when no icing is present, i.e., when the fan ring nozzle is not iced up.Thus, the current state of the fan ring nozzle can be determined based on the electrical current, which occurs particularly during operation. In this process, a virtually constant electrical voltage is always applied.

[0044] In particular, the area immediately between the two conductors, through which the smallest gap runs, consists of the electrically conductive plastic. In an alternative embodiment, the two conductors run essentially in the axial direction and, optionally, in the tangential direction. Here, the distance between the two conductors is advantageously relatively small, and the electrical conductivity in this area is low or nonexistent. For this purpose, the plastic may, for example, contain ceramic particles. The rest of the nozzle body, however, exhibits a higher electrical conductivity. Thus, the electric current flows tangentially around the cylinder axis, resulting in a comparatively large-area heating of the nozzle body when an electrical voltage is applied to the two conductors. Advantageously, the two conductors overlap in the tangential direction. This ensures that the entire nozzle body is heated.

[0045] For example, the fan ring nozzle, with the exception of the nozzle body, has no other components that define its outer contour. Alternatively, another ring is arranged on one end face of the nozzle body. This ring is designed, for example, as an inlet ring, and air is drawn into the nozzle body through this ring when the fan is operating. In particular, the inlet ring is comparatively widened on the side facing away from the nozzle body, thus reducing the formation of unwanted air turbulence. Alternatively, an outlet ring is arranged on one end face, through which the air passed through the nozzle body exits. In particular, this outlet ring is designed to direct the air into a specific area.

[0046] The inlet ring and the outlet ring are advantageously arranged concentrically to the nozzle body and / or are aligned with the nozzle body on the inside. Preferably, the inlet ring and / or the outlet ring are attached to the nozzle body and, for example, joined to it. For instance, they are glued together or connected by means of a bayonet fitting or screw connection. For example, the inlet ring and / or the outlet ring are made of the same material as the nozzle body, and in particular of plastic. Alternatively, the materials may differ. In this way, it is possible to design the inlet ring and / or the outlet ring to be relatively flexible, whereas the nozzle body is designed to be relatively rigid.If the heating element has two spaced-apart conductors, with the plastic between the conductors being electrically conductive, then, for example, the entire nozzle body is electrically conductive. The inlet ring and outlet ring, on the other hand, are made of a non-conductive plastic, thus improving electrical insulation.

[0047] Preferably, both the inlet ring and the outlet ring are present and arranged on opposite end faces of the nozzle body. In other words, the nozzle body is thus arranged axially between the inlet ring and the outlet ring.

[0048] Due to the inlet and outlet rings, the fan ring nozzle can be adapted to the specific evaporator / heat pump being used, while the nozzle body remains the same. Adaptation to existing conditions and / or attachment to other components is achieved using the appropriate inlet or outlet ring. It is also possible to adjust the inlet or outlet ring for different air volumes to be conveyed. Since the nozzle body is always the same, inventory management is simplified and manufacturing costs are reduced.

[0049] In its installed state, the heat pump is, for example, a component of a heating system or an air conditioning system. Specifically, the heat pump comprises a compressor driven by an associated electric motor, a heat exchanger, and an evaporator. Advantageously, the heat pump includes an expansion valve. Advantageously, a refrigerant circuit is formed by the compressor, the expansion valve, the heat exchanger, and the evaporator. The evaporator preferably has a cooling core through which the refrigerant flows during operation, changing its state of matter. Advantageously, the cooling core is covered by a housing to which a fan is attached. When the fan is operating, ambient air is drawn or blown through the cooling core. In particular, a fan nozzle is attached to other components of the housing.The fan also features a fan wheel driven by an associated electric motor. The fan wheel is conveniently located within the fan ring nozzle. The fan ring nozzle comprises a hollow cylindrical nozzle body made of plastic and an electric heating element. The heating element is integrated into the nozzle body.

[0050] The invention further relates to a fan with such a fan ring nozzle and an evaporator comprising a corresponding fan ring nozzle, preferably the fan itself. In particular, the evaporator has a frame by means of which a cooling core of the evaporator or the like is covered, and which includes the fan ring nozzle. Preferably, the fan ring nozzle is attached to other components of the frame, for example, permanently or, more preferably, detachably.

[0051] The further training and advantages explained in connection with the fan ring nozzle can also be applied analogously to the heat pump / the fan / the evaporator as well as to each other and vice versa.

[0052] Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. The drawing shows: Fig. 1 schematically a heat pump with a fan which has a fan ring nozzle, Fig. 2 schematically in a sectional view a section of the fan ring nozzle, which includes a nozzle body in which a heating element is integrated, Fig. 3. Schematic perspective view of the fan ring nozzle, with the nozzle body shown transparently. Fig. 4 in a representation according to Fig. 3. Further development of the fan ring nozzle, Fig. 5-7 each schematically in a sectional view show further alternatives of the fan ring nozzle in excerpts, and Fig. 8 schematically, in perspective, a final alternative of the fan ring nozzle.

[0053] Corresponding parts are marked with the same reference symbols in all figures.

[0054] In Fig. Figure 1 schematically simplifies a heat pump 2, which is a component of a residential building's heating system. The heat pump 2 has a refrigerant circuit 4 with a compressor 6. During operation, the compressor 6 compresses and thus heats a refrigerant. The heat is transferred via a heat exchanger (not shown) downstream of the compressor 6 to a fluid in the heating system (not shown). The cooled refrigerant is then fed to an expansion valve 8, which reduces the refrigerant pressure back to its original value, thus cooling the refrigerant. The cooled refrigerant is then directed to an evaporator 10. This evaporator has a cooling core 12 in which the refrigerant-carrying pipes are embedded. The cooling core 12 provides a relatively large surface area, thereby improving heat absorption from the surroundings.The refrigerant is then directed to compressor 6, which performs a further compression.

[0055] To improve heat exchange, a fan 14, comprising a fan wheel 16, is attached to the evaporator 10. This fan wheel 16 is driven by an electric motor (not shown) so that it rotates about an axis of rotation 17. The fan wheel 16, designed as an axial fan wheel, is arranged such that when the electric motor is operating, an airflow is generated, by means of which air is drawn or blown through the cooling core 12. To prevent the air from flowing around the edge of the cooling core 12, the fan 14 has a frame 18, which is attached to the cooling core 12. A fan ring nozzle 20 is attached to the frame 18, circumferentially surrounding the fan wheel 16. Thus, when the fan wheel 16 is operating, air is drawn in through the fan ring nozzle 20 and, due to the frame 18, can only escape through the cooling core 12.When the fan wheel 16 is operated in reverse, air is discharged from the space formed between the frame 18 and the cooling core 12 via the fan ring nozzle 20. Air can then only flow in through the cooling core 12.

[0056] In Fig. 2 is shown in part in a sectional view along the axis of rotation 17 and schematically simplified in Fig. Figure 3 shows the fan ring nozzle 20. The fan ring nozzle 20 has a hollow cylindrical nozzle body 22, which is arranged around the axis of rotation 17 and which is funnel-shaped and which is Fig. 3 shown transparently. The nozzle body 22 is made of a plastic, in the example shown, polypropylene (PP).

[0057] Furthermore, the fan ring nozzle 20 has a heating element 24, which is designed as a graphite strip. The heating element 24 is designed such that it heats up when energized, i.e., when an electrical voltage is applied to the terminals of the heating element 24. The heating element 24 is integrated into the nozzle body 22 and embedded in the plastic from which the nozzle body 22 was manufactured by injection molding. During manufacturing, the heating element 24 is overmolded with the plastic. Thus, the heating element 24 is completely enclosed within the nozzle body 22 and is not visible. The strip-shaped heating element 24 is guided once around the axis of rotation 17, which corresponds to the axis of the cylindrical nozzle body 22. Consequently, the heating element 24 has a tangential orientation.

[0058] The two ends of the heating element 24 overlap tangentially and are spaced apart axially. The terminals located at opposite ends of the heating element 24 are electrically connected to an electronics unit 26, which is also embedded in the nozzle body 22 and overmolded with plastic. The electronics unit 26, in turn, has further terminals 28 that protrude from the radial outer surface of the nozzle body 22 and, in the assembled state, are connected to a controller of the heat pump 2.

[0059] If icing is present inside the fan ring nozzle 20 and / or on the cooling core 12, preventing the fan wheel 16 from rotating, the heating element 24 is energized by the electronics 26, thus heating it and consequently the nozzle body 22. As a result, any ice that may have accumulated there is thawed, allowing the fan wheel 16 to rotate freely again. Since the heating element 24 is completely enclosed within the nozzle body 22, it is protected from damage. It is also prevented from detaching from the nozzle body 22, which could otherwise lead to a blockage of the fan wheel 16. Furthermore, it is ensured that the heat provided by the heating element 24 is used to heat the nozzle body 20 and does not escape into the environment.Due to the tangential overlap of the heating element 24, the formation of an area in which the fan wheel 16 can freeze to the inside of the fan ring nozzle 20 without this area being directly heated is avoided.

[0060] In Fig. 4 is a further training course in Fig. Figure 3 shows the fan ring nozzle 20. The nozzle body 22 is unchanged and remains hollow cylindrical, arranged around the axis of rotation 17, and is made of the same material. The electronics 26, not shown in detail, are also embedded in the nozzle body 22. Only the heating element 24 is now extended and looped several times around the axis of rotation 17. The heating element 24 has a helical shape. Thus, when the heating element 24 is operated, a comparatively large area of ​​the nozzle body 22 is heated, and there are hardly any areas where direct heating does not occur.

[0061] In Fig. 5 is according to the Fig. Figure 2 shows another alternative of the fan ring nozzle 20. Here, too, the nozzle body 22, made of plastic, is present, in which the electronics 26 with the additional connections 28 are embedded. These connections protrude from the radially outer side of the nozzle body 22. The heating element 24 is also unchanged; however, it extends to the radial inner side of the nozzle body 22 and is therefore not completely encased in the plastic. During the manufacturing of the nozzle body 22, the plastic is injection-molded onto the heating element 24, so that a material-bonded and form-fitting connection between the plastic forming the nozzle body 20 and the heating element 24 is maintained, which is thus embedded in the plastic. With such an arrangement, damage to the heating element 24 is possible, especially if foreign particles are drawn in through the fan ring nozzle 20.However, a comparatively effective transfer of heat to the inside of the nozzle body 22 and the fan wheel 16 located there is possible.

[0062] In Fig. Figure 6 shows another embodiment of the fan ring nozzle 20. The shape of the nozzle body 22 remains unchanged, and the electronics 26 are embedded within it. These electronics have additional connections 28, which extend out of the nozzle body 22. The heating element 24 is now modified and has two conductors 30 running parallel to each other and spaced apart axially, i.e., parallel to the axis of rotation 17. Each conductor is formed by an uninsulated wire. These conductors are overmolded with the plastic of the nozzle body 22. The nozzle body 22 has an electrically conductive area 32 in which the two conductors 30 are located. For this purpose, carbon is added to a portion of the polypropylene, namely the portion located between and around the conductors 30.As a result, an electric current flow is possible between the two conductors 30, even if they are spaced apart from each other and there is no direct mechanical contact between them.

[0063] The path of the conductors 30 is essentially the same as that of the ribbon-shaped heating element 24 in the previous embodiments. However, the heating element 24 is no longer sharply distinguishable from the nozzle body 22. Rather, the heating element 24, namely the electrically conductive area 32, is integral with the nozzle body 22, and the electrically conductive area 32 is both a part of the nozzle body 22 and a part of the heating element 24. In summary, the heating element 24 thus comprises the two spaced-apart conductors 30, which are arranged in the nozzle body 22, with the plastic between the two conductors 30 being electrically conductive.

[0064] In Fig. Figure 7 shows another embodiment of the fan ring nozzle 20. This embodiment has the same shape as the previous embodiments; however, the external appearance is now formed not only by the nozzle body 22, but only a part of it. The two conductors 30 are still embedded in the nozzle body 22, and the complete nozzle body 22 is formed by the electrically conductive area 32. In other words, the nozzle body 22 has a constant electrical conductivity. Furthermore, the fan ring nozzle 20 has an inlet ring 34 and an outlet ring 36, which are manufactured from a different plastic by injection molding and are arranged on opposite end faces of the nozzle body 22 and attached to it. The inlet ring 34, the nozzle body 22, and the outlet ring 36 together define the external shape of the fan ring nozzle 20.With this design, the manufacture of the nozzle body 22 is simplified, and adaptation to different heat pumps 2 is possible, for which the inlet ring 34 and / or the outlet ring 36 are modified accordingly. These are attached to the opposite end faces of the hollow cylindrical nozzle body 22, in particular by screwing them in place.

[0065] In Fig.Figure 8 schematically simplifies a final variant of the fan ring nozzle 20, which has the hollow cylindrical nozzle body 22. The two conductors 30 have an axial and slightly tangential orientation with respect to the axis of rotation 17, the tangential orientation being chosen such that the conductors 30 slightly overlap. In the region of smallest distance between the conductors 30, there is an electrically non-conductive area 38, and the electrically conductive area 32 represents the remainder of the nozzle body 22. Thus, when an electrical voltage is applied to the conductors 30, the electric current flows essentially around the axis of rotation 17, so that the nozzle body 22 is heated over a large area.

[0066] The invention is not limited to the embodiments described above. Rather, other variants of the invention can also be derived by those skilled in the art without departing from the subject matter of the invention. In particular, all individual features described in connection with the individual embodiments can also be combined with one another in other ways without departing from the subject matter of the invention. Reference symbol list 2 Heat pump 4 Refrigerant circuit 6 Compressor 8 Expansion valve 10 evaporators 12 Cooling core 14 fans 16 fan wheel 17 Rotation axis 18 frame 20 fan ring nozzle 22 nozzle bodies 24 heating elements 26 Electronics 28 more connections 30 ladders 32 electrically conductive area 34 Inlet ring 36 exhaust ring 38 electrically non-conductive area

Claims

[1] Fan ring nozzle (20) for a fan (14), in particular of an evaporator (20), comprising a hollow cylindrical nozzle body (22) made of plastic and an electric heating element (24), wherein the heating element (24) is integrated into the nozzle body (22). [2] Fan ring nozzle (20) according to claim 1, characterized by , that the heating element (24) is embedded in the plastic. [3] Fan ring nozzle (20) according to claim 2, characterized by , that the heating element (24) is overmolded with the plastic. [4] Fan ring nozzle (20) according to one of claims 1 to 3, characterized by , that the heating element (24) is designed in a ribbon shape and has a course at least in the tangential direction. [5] Fan ring nozzle (20) according to claim 4, characterized by , that the heating element (24) overlaps in the tangential direction. [6] Fan ring nozzle (20) according to claim 5, characterized by , that the heating element (24) has a helical shape. [7] Fan ring nozzle (20) according to one of claims 1 to 6, characterized by , that the heating element (24) is at least partially integral with the nozzle body (22). [8] Fan ring nozzle (20) according to claim 7, characterized by , that the heating element (24) has two conductors (30) spaced apart from each other, which are arranged in the nozzle body (22), wherein the plastic between the conductors (30) is electrically conductive. [9] Fan ring nozzle (20) according to one of claims 1 to 8, characterized by , that an inlet ring (34) and an outlet ring (36) are arranged on the opposite end faces of the nozzle body (22). [10] Heat pump (2) with an evaporator (10) to which a fan (14) with a fan ring nozzle (20) according to one of claims 1 to 9 is attached.

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