Air heat pump heat source unit

Abstract

The heat source unit (1) of the air heat pump includes a casing (10), a fan (22) accommodated in the casing (10) and rotatable about a central axis (30), a bellmouth (32) having an opening (32), and grills (40, 42) covering the opening (32). The grills (40, 42) include a plurality of longitudinal first louvers (46). Each of the first louvers (46) has an inlet portion (66) facing the fan (22), and at least the inlet portion (66) is inclined with respect to the central axis (30) of the fan (22). The angle of inclination (α) varies along the longitudinal direction of each first louver (46).

Description

[Technical Field]

[0001] The present disclosure relates to a heat source unit of an air heat pump, and in particular to the configuration of the grill thereof. [Background technology]

[0002] Generally, in its simplest form, a heat pump consists of a refrigerant circuit that connects a user-side heat exchanger, a compressor, a heat source-side heat exchanger, and an expansion valve, and the refrigerant circulates through the refrigerant circuit to transport heat or cold from the heat source-side heat exchanger to the user-side heat exchanger.

[0003] The heat source unit of such a heat pump is usually installed outdoors and has a heat source heat exchanger for exchanging heat between outside air and a refrigerant. For this reason, the heat source unit includes a casing, a fan housed in the casing and rotatable about a central axis, and a bell mouth having an opening centered on the central axis of the fan so that the airflow induced by the fan passes through the heat source heat exchanger.

[0004] To comply with industry standards and regulations, a grill or fan guard is provided which covers the bellmouth opening and therefore the fan blades of the fan.

[0005] Such a heat source unit is disclosed, for example, in European Patent Application Publication No. 3705732 (EP3705732A1). The grille is composed of a plurality of horizontal louvers that have a considerable depth in a direction parallel to the central axis of the fan, which visually conceals the fan when the grille is viewed at a certain angle relative to the central axis of the fan, resulting in an improved appearance.

[0006] However, the greater depth creates greater obstructions to the airflow induced by the fan, which creates more vortices, which can create noise that can be perceived as annoying, especially if the heat source unit is installed near a window. summary In consideration of the above, an object of the present disclosure is to provide a heat source unit for an air heat pump that is quieter during operation while maintaining maximum airflow and making the fan less visible.

[0007] This object is achieved by a heat source unit as defined in claim 1. Further embodiments of the heat source unit are defined in the dependent claims.

[0008] For this purpose, the present invention can be defined as a heat source unit for an air heat pump, the heat source unit comprising: a casing; a fan housed in the casing and rotatable about a central axis; a bell mouth having an opening centered on the central axis of the fan for passing airflow induced by the fan; and a grill covering the opening, the grill comprising a plurality of longitudinal first louvers having a first end, a second end opposite the first end, and a center between the first end and the second end, each of the first louvers having an inlet portion facing the fan, at least the inlet portion being inclined with respect to the central axis of the fan, the angle of inclination varying in the longitudinal direction of each first louver, the angle of inclination decreasing from a positive maximum angle toward the first end and the center in the first portion between the first end and the center, and / or increasing from a negative maximum angle toward the center and the second end in the second portion between the center and the second end.

[0009] In a first aspect, a heat source unit of an air heat pump includes a casing and a fan housed within the casing and rotatable about a central axis. The heat source unit further includes a bellmouth having an opening centered on the central axis of the fan, through which the airflow induced by the fan passes. The heat source unit may further include the heat source heat exchanger of the heat pump described above, where the airflow induced by the fan passes through the opening in the bellmouth and then passes through the heat source heat exchanger to exchange heat / cold with the refrigerant flowing through the heat source heat exchanger. To comply with industrial standards and regulations, such as finger safety, the opening in the bellmouth is covered with a grill. The grill, or at least a portion thereof corresponding to the bellmouth opening, includes a plurality of first longitudinal louvers. In this context, the term "first" is intended to distinguish between first and second louvers within this disclosure, but does not necessarily mean that two types of louvers exist. In this context, the "first louvers" may also be referred to as guide louvers, in the sense that they are intended to guide the airflow induced by the fan.

[0010] The first louvers are elongate having a longitudinal extension / direction defined between a first end and a second end opposite the first end. A center can be defined between the first and second ends. The first louvers also have a depth, which is a dimension perpendicular to the longitudinal extension and parallel to the central axis of the fan, and a height, which is a dimension perpendicular to the longitudinal extension and the central axis of the fan.

[0011] Each of the first louvers has an inlet portion facing the fan in its depth direction. In other words, the inlet portion extends from the fan end facing the fan toward the outside of the heat source unit. At least the inlet portion is inclined with respect to the central axis of the fan. In this context, "at least the inlet portion" includes an embodiment in which only a portion of the first louver in the depth direction is inclined, and an embodiment in which the entire first louver in the depth direction is inclined.

[0012] On the first surface, the angle of inclination varies along the length of each first louver. The angle of inclination may vary continuously or gradually along the length of each first louver. Optionally, the angle of inclination may vary in steps.

[0013] The angle of inclination decreases from a positive maximum angle in a first portion between the first end and the center toward the first end and the center. In other words, the angle of inclination is maximum at a position between the first end and the center and decreases from that position toward the first end and the center. The angle of inclination can decrease continuously or gradually from the positive maximum angle in the first portion.

[0014] Alternatively or additionally, the angle of tilt increases from a maximum negative angle in a second portion between the center and the second end toward the center and the second end. In other words, the angle of tilt is minimum at a position between the center and the second end and increases from that position toward the center and the second end. The angle of tilt can increase continuously or gradually from the maximum negative angle in the second portion.

[0015] In other words, each first louver twists longitudinally from a first end at a first angle (e.g., 0°) relative to the central axis of the fan in a first rotational direction to a maximum angle (most positive angle) relative to the central axis of the fan, and then twists from the maximum angle (most positive angle) back to a second angle (e.g., 0°) in a second rotational direction opposite the first rotational direction; and / or twists from a center at a second angle (e.g., 0°) in a second rotational direction to a maximum angle (most negative angle), and then twists from the maximum angle (most negative angle) in the first rotational direction back to the first angle (e.g., 0°) at the second end.

[0016] The absolute values ​​of the maximum positive angle and maximum negative angle can be the same for the same first louver, and can be different between two different first louvers (see below).

[0017] On the first side, the first louvers are at least partially inclined. It is assumed that the airflow vector varies depending on the radial position relative to the center of the fan, particularly in the airflow region of the fan defined between two concentric circles. Therefore, the angle of inclination varies along the longitudinal direction of the first louvers. Therefore, the angle of inclination can correspond to the direction of the airflow (airflow vector) induced by the fan at each position of the first louvers. In particular, the angle of inclination can be substantially adapted to the airflow direction (airflow vector) at each position of the first louvers.

[0018] As a result, the louvers do not obstruct the airflow, but rather guide it from the fan edge to the outer edge, reducing vortex generation. This results in less noise. Because the first louver does not obstruct the airflow, the fan can also operate at a lower RPM (revolutions per minute) while achieving the same airflow, further reducing noise. This results in a quieter heat source unit.

[0019] On the second surface, the angle of inclination is 0° at the first and second ends and / or the center. In other words, the first louvers extend such that their depth is parallel to the central axis of the fan at the first and second ends and / or the center.

[0020] In a third aspect, the first louvers extend from one side of the grill to the other opposite side of the grill. In one embodiment, the first louvers can extend linearly from one side of the grill to the other opposite side of the grill. The grill can be a front grill of a trunk-type heat source unit. In this case, the first louvers can extend horizontally (from left to right) or vertically (from bottom to top) from one side to the other. It is also conceivable that both the horizontal and vertical louvers include the first louvers according to the present disclosure. However, for ease of manufacturing, it is preferable that either the horizontal or vertical louvers include the first louvers. In this context, depending on the direction of rotation of the fan, the maximum positive angle can be located on one side (left / right or top / bottom) and the maximum negative angle can be located on the other side (right / left or bottom / top), i.e., the first end can be the left / right end or the top / bottom end, and the second end can be the right / left end or the bottom / top end. Optionally, the grill can be a top grill of a top-blow type heat source unit. In this case, the first louver can extend horizontally from one side to the other. Also, in this case, the first louver can extend horizontally from front to rear and / or from left to right. Also, here, the maximum positive angle can be located on one side (left / right or front / rear) and the maximum negative angle can be located on the other side (right / left or rear / front), i.e., the first end can be the left / right end or the front / rear end, and the second end can be the right / left end or the rear / front end.

[0021] On the fourth surface, the first louvers are arranged parallel to one another, and the maximum positive and maximum negative angles differ between the first louvers in the direction of the louvers. In the case of a trunk-type heat source unit, when the first louvers are horizontal, the direction of the louvers is sometimes referred to as the stacking direction.

[0022] In a fifth aspect, the grille further comprises non-tilted longitudinal secondary louvers. As detailed above, the term "second" is used solely to distinguish the secondary louvers from the primary louvers. The secondary louvers may also be referred to simply as non-tilted louvers. In particular, the grille may have areas where there is little or no airflow, eliminating the need for a tilt angle. Rather, the secondary louvers have a depth that extends parallel to the central axis of the fan and are therefore non-tilted.

[0023] In a sixth aspect, the inclination angle (tilt angle) of the first louvers of the grille is symmetrical with respect to a first line passing through the central axis of the fan and extending perpendicular to the central axis of the fan, and / or with respect to a second line passing through the central axis of the fan and extending perpendicular to the central axis of the fan and the first line. The airflow induced by the fan is assumed to be symmetrical as well as the airflow vector. As previously indicated, the inclination angle corresponds to each airflow direction (airflow vector). Therefore, it is preferable that the inclination angle of the first louvers is also symmetrical.

[0024] In an optional aspect, the first louvers are radially extending louvers that pass through the central axis of the fan. In particular, the grille can be a circular grille or have a circular portion on which the first louvers are provided. Also, in this context, radially extending includes first louvers that are longitudinally curved but radiate outward from the center. The grille can have an even number of first louvers. In this case, the first louvers can be straight or curved, extending diametrically from one outer periphery to the opposite outer periphery, through the center, with one side having a maximum positive angle and the other side having a maximum negative angle. This grille can also have identical first louvers arranged radially, each extending from the center toward the outer periphery. In this case, the angle of inclination of the first louvers decreases from a maximum positive angle between the first end and the center toward the first end and the center. In other words, the angle of inclination is maximum at a position between the first end and the center and decreases from that position toward the first end and the center. The angle of inclination can decrease continuously or gradually from the maximum positive angle in the first portion. Therefore, the grille can have an odd number of first louvers.

[0025] In an eighth aspect, the first louvers have a depth perpendicular to their longitudinal direction and parallel to the central axis of the fan of at least 15 mm, preferably at least 20 mm, and more preferably at least 25 mm. Thus, the first louvers have a depth large enough to, on the one hand, visually conceal the fan when the grille is viewed at an angle to the central axis of the fan, and, on the other hand, to guide the airflow and avoid the creation of vortices and, therefore, noise. In this context, a balance must be struck between a large depth that is useful for guiding the airflow and a short depth that does not create an obstruction.

[0026] In a ninth aspect, the first louver has an outer edge facing the outside of the heat source unit and an opposite fan edge facing the fan, the fan edge being wavy when viewed parallel to the central axis of the fan and / or the outer edge being straight when viewed parallel to the central axis of the fan. The wavy shape of the fan edge makes it easy to match the angle of inclination to the respective airflow vectors at each position, while also enabling injection molding of the grille. The straight outer edge also improves the appearance of the grille. The straight, for example parallel (horizontal) or concentric relative positional relationship of the outer edges further promotes parallel laminar airflow, which reduces the generation of turbulence and therefore noise.

[0027] In a tenth aspect, the first and / or second louvers have, in a cross section perpendicular to their longitudinal direction, curved fan edges facing the fan, which are less obstructive than flat surfaces facing the fan and reduce vortex generation and therefore noise.

[0028] In an eleventh aspect, the first and / or second louvers have a curved outer edge facing the outside of the heat source unit in a cross section perpendicular to the longitudinal direction thereof, the curved outer edge reducing turbulence at the outer edge and thereby reducing noise generation.

[0029] In a twelfth aspect, the radius of curvature of the curved fan edge is equal to or greater than the radius of curvature of the curved outer edge. As a result, the first and second louvers exhibit a drop or airfoil shape in a cross section parallel to the central axis of the fan and perpendicular to the longitudinal extent of the first and second louvers. This drop shape reduces turbulence and provides a quieter heat source unit.

[0030] In the thirteenth aspect, the grille has a central portion centered on the central axis of the fan, the central portion having a closed guide portion facing the fan, the guide portion being dome-shaped toward the fan. The dome shape guides the central airflow toward the first louver, thereby avoiding a central dead zone. Furthermore, the closed guide portion conceals the central portion (hub) of the fan. Furthermore, the closed guide portion prevents re-entry of the airflow, which may cause excessive turbulence within the casing.

[0031] In a fourteenth aspect, the first louver has, in a cross section perpendicular to its longitudinal direction and parallel to the central axis of the fan, an inlet portion where the first louver is inclined with respect to the central axis of the fan, and an outlet portion where the first louver is parallel to the central axis of the fan.

[0032] In the fifteenth aspect, the first louver is curved in a cross section perpendicular to its longitudinal direction and parallel to the central axis of the fan, i.e., the inlet portion is connected to the outlet portion via a curved surface.

[0033] In the sixteenth aspect, the fan is a propeller fan. Propeller fans are distinguished from turbofans and centrifugal fans. A propeller fan is a simple type of fan, typically made of sheet metal or plastic, with an impeller with three to six blades, driven directly by a motor mounted in the air stream or flow. [Brief explanation of the drawings]

[0034] Embodiments of the present disclosure are described below with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 is a perspective view of a heat source unit according to a first embodiment. [Figure 2] FIG. 2 is a perspective view of the fan side of the grill of the first embodiment. [Figure 3] FIG. 2 is a front view of the grill of the first embodiment. [Figure 4] FIG. 2 is a rear view of the grille of the first embodiment. [Figure 5A] 5A is a cross-sectional view of the heat source unit of the first embodiment taken along line 5A-5A in FIG. [Figure 5B] 5B is a cross-sectional view of the heat source unit of the first embodiment taken along line 5B-5B in FIG. [Figure 5C] 5C is a cross-sectional view of the heat source unit of the first embodiment taken along line 5C-5C in FIG. [Figures 6A-6C] 5B is a cross-sectional view of the grille of FIGS. 5A to 5C in isolation. FIG. [Figure 7] FIG. 10 is a perspective front view of a grille according to a second embodiment. [Figure 8] FIG. 8 is a side view of the grill of FIG. 7. [Figure 9] FIG. 10 is a front view of the grill of the second embodiment. [Figure 10]10 is a rear view of the grille of the second embodiment. DETAILED DESCRIPTION In the following description and drawings, the same reference numerals are used throughout the embodiments to refer to the same or similar features.

[0035] FIG. 1 shows a trunk-type heat source unit 1 of an air heat pump. Note that the present disclosure can also be embodied in a top-blow heat source unit. The heat source unit 1 includes a housing (casing) 10 that houses components of the refrigerant circuit of the air heat pump, such as the heat source heat exchanger 20 (shown in FIG. 5) described above. Other components of the refrigerant circuit and / or the air heat pump, such as a compressor, expansion valve, controller, etc. (not shown), can also be housed within the casing 10.

[0036] The casing 10 includes a top plate 12, a bottom plate 14, and a right side plate 16. The plates 12, 14, and 16 can be formed from sheet metal. The casing 10 can further include a back plate (not visible in the figure) that covers a portion of the back side of the heat source unit 1, particularly the portion corresponding to the machine compartment where other components of the refrigerant will be accommodated.

[0037] The heat source heat exchanger 20 may be L-shaped in top view, covering the side of the heat source unit opposite the side panel 16 (the shorter leg of the "L") and the remainder of the back side of the heat source unit 1 (the longer leg of the "L"). In use, a refrigerant flows through the heat source heat exchanger 20, exchanging heat / cold with the air. In this context, the term "heat" with respect to the heat source heat exchanger 20 is used in a thermodynamic sense. That is, "heat" is the amount of energy that flows spontaneously from one object to another due to a temperature difference between them, whether "heat" is transferred from the air to the refrigerant during heating operation or vice versa during cooling operation.

[0038] To force air through the heat source heat exchanger 20, the casing 10 houses a fan 22, which in this embodiment is a propeller fan. A propeller fan is a relatively simple type of fan, typically made from sheet metal or plastic, with an impeller having 3 to 6 blades driven directly by a motor attached to the air stream or flow.

[0039] The fan 22 includes a hub 24 connected to a motor 26 (see FIG. 5). A plurality of fan blades 28 are connected to the hub 24. The fan 22 can rotate around a central axis 30 (rotation axis) by operation of the motor 26.

[0040] Furthermore, a bell mouth 32 is disposed in front of the fan 22 so that the fan 22 is disposed between the bell mouth 32 and the heat source heat exchanger 20. The bell mouth 32 has an opening 34, preferably a circular opening, centered on the central axis 30 of the fan 22.

[0041] Airflow is induced by the rotation of the fan 22. Specifically, in this embodiment, air is drawn into the casing 10 to pass through the heat source heat exchanger 20 and then blown out of the casing 10 through the opening 34 in the bell mouth 32.

[0042] To meet industry standards and regulations, it is important to keep hands or fingers out of the way of the fan, so the front of the casing 10 is provided with a grill 40 which covers the opening 34 in the bellmouth 32. The grill 40 can be made of plastic and can be formed using an injection molding process.

[0043] In this embodiment, the grill 40 comprises a fan portion 42 that extends across the entire front of the casing 10 for aesthetic purposes and is configured to allow air to pass through the grill 40, and a machine compartment portion 44 that does not allow air to pass through and has a closed surface that is provided primarily for design purposes. This disclosure is directed specifically to the configuration of the fan portion 42. Therefore, in this disclosure, when referring to the grill 40, it is the fan portion 42 of the grill that is meant.

[0044] Grille 40 includes a plurality of first louvers 46 (also referred to as guide louvers or angled louvers) and a plurality of second louvers 48 (also referred to as non-angled louvers).

[0045] In this embodiment, the first louvers 46 and the second louvers 48 extend from one side 50 (here, the left side) of the grille 40, which in this particular embodiment is the fan portion 42, to the other opposite side 52 (here, the right side) of the grille 40, which in this particular embodiment is the fan portion 42. In this embodiment, the first and second louvers 46, 48 extend horizontally. The first and second louvers 46, 48 are arranged parallel to each other in the arrangement direction (here, the stacking direction from bottom to top). The distance between adjacent louvers 46, 48 can be between 20 mm and 40 mm, or 25 mm to 35 mm.

[0046] The first and second louvers 46, 48 have a fan edge 56 facing the fan 22 and an outer edge 58 facing the outside of the heat source unit 1 (casing 10). When viewed in cross section in the depth direction (longitudinal extension, i.e., a direction perpendicular to the length and height), the first and second louvers 46, 48 can have a curved fan edge 56 and a curved outer edge 58. The radii of curvature of the curved fan edge 56 and the curved outer edge 58 can be the same. Optionally, the radius of curvature of the curved fan edge 56 can be larger than the radius of curvature of the curved outer edge 58. As a result, the first and second louvers 46, 48 can have a cross-sectional shape similar to a drop or airfoil.

[0047] Additionally, the outer edges 58 of the first louvers 46 and the second louvers 48 can be surfaces, i.e., the outer edges are positioned on a common plane (e.g., a plane perpendicular to the central axis 30 of the fan 22, a curved surface such as the sheath of a cylinder or the surface of a sphere, etc.) for aesthetic purposes.

[0048] The first and second louvers 46, 48 are longitudinal, with their length L being the largest dimension compared to their depth D and height H. Because the first and second louvers 46, 48 are flat or plate-like, their height H (thickness) is less than their depth D. The depth D, perpendicular to their longitudinal direction and parallel to the central axis 30 of the fan 22, can be at least 15 mm, at least 20 mm, or at least 25 mm. Meanwhile, the depth D must be 55 mm, 45 mm, or 35 mm or less. The height H can be 8 mm or less, 6 mm or less, or 5 mm or less. The height varies depending on the depth. In particular, the height H can be greater at the edge of the fan than at the outer edge.

[0049] Three distinct zones of airflow A1, A2, and A3 are defined by concentric rings when viewed parallel to the central axis 30 of the fan 22. The outer zone A1 has little or only a relatively low airflow velocity, while the central zone A3 has little to no airflow. In contrast, the middle zone A2 has a high airflow velocity or a relatively high airflow velocity. Zones A1 through A3 are shown schematically in FIG. 4.

[0050] The first louvers 46 are disposed primarily in the region that crosses the opening 34 of the bellmouth 32, and therefore in the region of air flow where the air flow velocity is significantly high. In other words, the first louvers 46 are disposed primarily in the intermediate zone A2. Note that, because the first louvers 46 extend horizontally from one side of the grille 40 to the other side of the grille 40 (here, from left to right), some of the first louvers 46 also cross the central zone A3.

[0051] The first louver 46 has, along its longitudinal direction (length L), a first end 60, a second end 62 opposite the first end 60, and a center 64 between the first end 60 and the second end 62. The center 64 may be centered on the central axis 30 of the fan 22.

[0052] Each of the first louvers 46 has, in the depth direction, an inlet portion 66 facing the fan 22 and an outlet portion 68 facing the outside of the heat source unit 1 / casing 10.

[0053] In an embodiment not shown, the first louvers 46 can be flat or plate-like and can be angled relative to the central axis 30 of the fan 22. In other words, the line connecting the tip of the fan edge 56 to the tip of the outer edge 58 is straight but angled relative to the central axis 30 of the fan 22.

[0054] It should be noted that in the present disclosure, at least the inlet portion 66 is inclined relative to the central axis 30 of the fan 22 .

[0055] It will also be appreciated that the direction in which the airflow approaches the fan edge 56 of the first louver 46 within the intermediate zone A2 will be different within this intermediate zone A2.

[0056] First, the airflow velocity decreases toward the boundary with the outer zone A1 and the boundary with the central zone A3, and the angle at which the airflow approaches the fan edge 56 is greatest halfway between the boundary with the outer zone A1 and the boundary with the central zone A3. As a result, the angle at which the airflow approaches the fan edge 56 varies depending on the longitudinal direction of each first louver 46.

[0057] Second, the angle at which the airflow approaches the fan edge 56 can be varied depending on the orientation of the louvers. That is, the angle at which the airflow approaches the fan edge 56 at a specific longitudinal position of each louver can be varied when considering an adjacent louver at the same specific longitudinal position. Furthermore, the maximum angle at which the airflow approaches the fan edge 56 can be varied depending on the orientation of the louvers, i.e., between adjacent louvers.

[0058] One basic idea of ​​the present disclosure is to angle at least the inlet portion 66 of each first louver 46 so that the angle at which the airflow approaches the fan edge 56 matches the angle of inclination α of each first louver 46 at each position along its length.

[0059] In this embodiment, the angle of slope α varies (here continuously or gradually, but optionally stepped) along the length of each first louver 46. In particular, the angle of slope α decreases from a positive maximum angle toward the first end 60 and the center 64 in a first portion 70 between the first end 60 and the center 64. In a second portion 72 between the center 64 and the second end 62, the angle of slope α increases from a negative maximum angle toward the center 64 and the second end 62.

[0060] In this embodiment, the angle of inclination α is 0° at the first end 60, the second end 62, and the center 64. In other words, the first louver 46 is flat or plate-like with its depth (inlet and outlet portions 66, 68) parallel to the central axis 30 of the fan 22 at the first end 60, the second end 62, and the center 64.

[0061] The absolute value of the maximum positive angle and the absolute value of the maximum negative angle range between 24° and 60°, preferably between 35° and 55°.

[0062] The angle of inclination α varies continuously along the length of each first louver 46, so that the fan edge 56 has a wavy shape when viewed parallel to the central axis 30 of the fan 22 (see FIG. 4).

[0063] To improve appearance, it is advantageous for the outer edge 58 of each first louver 46 to be straight (here horizontal) when viewed parallel to the central axis 30 of the fan 22 .

[0064] As previously indicated, the angle at which the airflow approaches the fan edge 56 can also be varied depending on the orientation of the first louvers 46. That is, the angle at which the airflow approaches the fan edge 56 at a particular longitudinal position of each first louver 46 can be varied when considering an adjacent first louver 46 at the same particular longitudinal position. To adapt the angle of inclination α to the respective angles at which the airflow approaches the fan edge 56, the maximum positive and negative angles are different between first louvers 46, such as adjacent first louvers 46 in the orientation of the first louvers 46.

[0065] Furthermore, it will be appreciated that due to the symmetry of the fan 22, the angle at which the airflow approaches each fan edge 56 is also symmetrical, particularly in the intermediate zone A2. Thus, the configuration of the first louvers 46 is symmetric in terms of the angle of inclination α with respect to a first line L1 that passes through the central axis 30 of the fan 22 and extends in a first direction perpendicular to the central axis 30 of the fan 20, and / or with respect to a second line L2 that passes through the central axis 30 of the fan 22 and extends in a second direction perpendicular to the central axis 30 of the fan 22 and the first direction (see FIG. 4). In this embodiment, the configuration of the first louvers 46 is symmetrical with respect to both the first line L1 and the second line L2.

[0066] The configuration of the first louvers 46, and their angled inlet portions 66, match the direction of the airflow approaching the fan edge 56, thereby minimizing turbulence and vortices, thereby reducing noise generation. Additionally, the first louvers 46 of the present disclosure are less obstructive, thereby allowing the fan 22 to operate at a lower RPM to achieve the same airflow through the heat source heat exchanger 20, thereby helping to provide a quieter heat source unit 1.

[0067] In this embodiment, only the inlet portion 66 of the first louver 46 is inclined, while the first louver 46 is parallel to the central axis 30 of the fan 22 in the depth direction at the outlet portion 68. As a result, the outer edge 58 of the first louver 46 and the second louver 48 are linear (here horizontal) and parallel to each other.

[0068] To enable the first louvers 46 to perform a useful airflow guiding function, the first louvers are curved in a cross section perpendicular to the longitudinal and height directions (see FIG. 6). In other words, the inlet portion 66 and the outlet portion 68 are connected by a curved portion 78.

[0069] As mentioned above, there is little or no airflow toward the grill 40 in the central zone A1. To prevent air from re-entering the casing 10 through the grill 40 in this central zone A1, the grill 40 (here, the fan portion 42) has a central portion 74 centered on the central axis 30 of the fan 22. The central portion 74 may be circular when viewed in a direction parallel to the central axis 30 of the fan 22.

[0070] The central portion 74 has a closed surface that prevents air from passing through the central portion 74. As a result, the middle portion (hub 24) of the fan 22 is hidden and not visible from the outside.

[0071] The central portion 74 also has a dome-shaped guide portion 76 facing the fan 22 to guide the air toward the opening in the grille 40. This effectively prevents dead zones and turbulence between the front surface of the hub 24 and the guide portion 76.

[0072] The second louvers 48 are mainly disposed in the area outside the openings 34 at the top and bottom of the grille 40 when viewed in a direction parallel to the central axis 30 of the fan 22 (in a front view here). Furthermore, the second louvers 48 may also be provided in the area of ​​the openings 34 at the top and bottom of the grille 40 where the airflow speed is relatively low when viewed in a direction parallel to the central axis 30 of the fan 22 (in a front view).

[0073] The second louvers 48 are flat or plate-like and extend such that their depth is parallel to the central axis 30 of the fan 22 and their length (longitudinal direction) is perpendicular to the central axis 30 of the fan 22. The depth of the second louvers 48 can be the same as the depth of the first louvers 46.

[0074] The grill 40 further includes a third louver 54 extending perpendicular to the first and second louvers 46, 48 (here, in a direction from the bottom panel 14 toward the top panel 12). In this embodiment, the third louver 54 extends vertically. The third louver 54 has a smaller depth than the first and second louvers 46, 48. Furthermore, in this embodiment, the third louver 54 is not angled but is flat or plate-like. The main purpose of the third louver 54 is to provide finger and child finger safety, i.e., to prevent people from reaching the fan 22 with their fingers.

[0075] In the above-described embodiment, only the first louvers 46 (horizontal louvers) are inclined, i.e., provided with an inclined inlet, thereby maintaining ease of manufacture in the injection molding process.

[0076] Alternatively or additionally, some of the third louvers 54 may have the same configuration as the first louvers 46 in the above embodiment. In other words, the configuration of the first louvers 46 may be rotated 90 degrees and applied to the third louvers 54.

[0077] A second embodiment of the present disclosure, shown in FIGS. 7 to 10, is applied to a circular grille 40.

[0078] In this embodiment, the first louvers 46 extend radially. As the radial first louvers 46 are shown as straight, the first louvers 46 can extend radially, or they can be curved, as shown, for example, in EP 3705732 A1. Unlike the first embodiment, the absolute values ​​of the maximum positive angle and maximum negative angle can be the same for all of the first louvers 46 because the radial positioning of the first louvers 46 ensures that the respective positions along the length L of each first louver 46 relative to the fan 22 and the corresponding airflow direction induced by the fan 22 are the same.

[0079] The first louvers extending in the radial direction are further connected by concentric third louvers 54 .

[0080] The rest of the second embodiment is similar or the same as the first embodiment described above with respect to FIGS. List of reference numbers Heat source unit 1 Casing 10 Top plate 12 Bottom plate 14 Side panel 16 Heat source heat exchanger 20 Fan 22 Hub 24 Fan motor 26 Fan Blades 28 Central axis (rotation axis) 30 Bellmouth 32 Opening 34 Grill 40 Fan part 42 Machine room part 44 1st louver 46 Second louver 48 One side of the grill 50 Other side of the grill 52 3rd louver 54 Fan edge 56 Outer edge 58 First end 60 Second end 62 center 64 Entrance part 66 Exit part 68 Part 1 70 Part 2 72 central part 74 Information section 76 Curved section 78 Length L Depth D Height H Outer Zone A1 Intermediate Zone A2 Central Zone A3 1st straight line L1 2nd straight line L2 [Prior art documents] [Patent documents]

[0081] [Patent Document 1] European Patent Application Publication No. 3705732

Claims

1. A heat source unit (1) of an air heat pump, the heat source unit (1) comprising: A casing (10); a fan (22) accommodated in the casing (10) and rotatable around a central axis (30); a bell mouth (32) having an opening (34) centered on the central axis (30) of the fan (22) for passing an airflow induced by the fan (22); a grill (40, 42) covering the opening (34), the grill (40, 42) comprising a plurality of first longitudinal louvers (46); Each of the first louvers (46) has an inlet portion (66) facing the fan (22), and at least the inlet portion (66) is inclined with respect to the central axis (30) of the fan (22); The angle of inclination (α) varies along the length of each first louver (46); Each of the first louvers (46) a first portion (70) in which the angle of inclination (α) between the first end (60) of each of the first louvers (46) and a center (64) of the fan (22) about the central axis (30) decreases from a positive maximum angle toward the first end (60) and the center (64); and / or A heat source unit having a second portion (72) in which the angle of inclination (α) between the center (64) and the second end (62) of each of the first louvers (46) increases from a maximum negative angle toward the center (64) and the second end (62).

2. 2. The heat source unit (1) according to claim 1, wherein the angle of inclination (α) is 0° at the first end (60) and / or the second end (62) and / or the center (64).

3. The heat source unit (1) according to claim 1 or 2, wherein the first louver (46) extends from one side (50) of the grill (40, 42) to the other opposite side (52) of the grill (40, 42).

4. A heat source unit (1) according to any preceding claim, wherein the first louvers (46) are arranged in parallel, and the maximum positive angle and the maximum negative angle are different between the first louvers (46) in the arrangement direction of the first louvers (46).

5. 10. The heat source unit (1) according to any of the preceding claims, wherein the grill (40, 42) further comprises non-inclined longitudinal second louvers (48).

6. A heat source unit (1) according to any of the preceding claims, wherein the inclination angle (α) of the first louvers (46) of the grill (40, 42) is symmetrical with respect to a first line (L1) that passes through the central axis (30) of the fan (22) and extends perpendicular to the central axis (30) of the fan (22), and / or with respect to a second line (L2) that passes through the central axis (30) of the fan (22) and extends perpendicular to the central axis (30) of the fan (22) and the first line (L1).

7. The heat source unit (1) according to claim 1 or 2, wherein the first louvers (46) extend in a radial direction passing through the central axis (30) of the fan (22).

8. A heat source unit (1) according to any one of the preceding claims, wherein the first louvers (46) have a depth (D) perpendicular to their longitudinal direction and parallel to the central axis (30) of the fan (22) of at least 15 mm, preferably at least 20 mm, and more preferably at least 25 mm.

9. The first louver (46) has an outer edge (58) facing the outside of the heat source unit (1) and an opposite fan edge (56) facing the fan (22), A heat source unit (1) according to any preceding claim, wherein the fan edge (56) is wavy when viewed parallel to the central axis (30) of the fan (22), and / or the outer edge (58) is straight when viewed parallel to the central axis (30) of the fan (22).

10. A heat source unit (1) according to any one of the preceding claims, wherein the first and / or second louvers (46, 48) have, in a cross section perpendicular to their longitudinal direction, a curved fan edge (56) facing the fan (22).

11. A heat source unit (1) according to any preceding claim, wherein the first and / or second louvers (46, 48) have, in a cross section perpendicular to their longitudinal direction, a curved outer edge (58) facing the outside of the heat source unit (1).

12. 12. The heat source unit (1) according to claim 10 or 11, wherein the radius of curvature of the curved fan edge (56) is equal to or greater than the radius of curvature of the curved outer edge (58).

13. A heat source unit (1) as described in any of the preceding claims, wherein the grill (40, 42) has a central portion (74) centered on the central axis (30) of the fan (22), the central portion (74) having a closed guide portion (76) facing the fan (22), the guide portion (76) being dome-shaped toward the fan (22).

14. A heat source unit (1) according to any of the preceding claims, wherein the first louvers (46), in a cross section perpendicular to their longitudinal direction, have an inlet portion (66) in which the first louvers (46) are inclined with respect to the central axis (30) of the fan (22), and an outlet portion (68) in which the first louvers (46) are parallel to the central axis (30) of the fan (22).

15. The heat source unit (1) according to claim 14, wherein the first louver (46) is curved in a cross section perpendicular to its longitudinal direction.

16. The heat source unit (1) according to any of the preceding claims, wherein the fan (22) is a propeller fan.

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