Cross-flow fan unit, utilization unit, and air conditioning system

Abstract

This suppresses noise in cross-flow fan units. [Solution] The cross-flow fan unit (10) comprises a cross-flow fan (20) and a casing (30) that houses the fan (20). The casing (30) has a first passage (40) located downstream (Fb) of the fan (20) in the fluid (A) flow direction (F), and a second passage (60) located downstream (Fb) of the first passage (40) in the flow direction (F) and having a larger passage area (S) than the first passage (40). A step (71) is formed at the boundary (70) between the first passage (40) and the second passage (60). The casing (30) is provided with a hollow structure (80) in which a space (E) is formed inside (81). The wall portion (40a) constituting the first passage (40) is provided with an opening (82) that communicates with the space (E).

Description

Technical Field

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[0001] The present disclosure relates to a cross-flow fan unit, a utilization unit, and an air conditioner.

Background Art

[0002] Various techniques for cross-flow fan units have been disclosed. Cross-flow fan units have a drawback in that noise is likely to occur due to the number of fan blades and the rotational speed. In the cross-flow fan unit disclosed in Patent Document 1, by arranging a Helmholtz resonator near the fan, noise caused by the number of fan blades and the rotational speed is reduced.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a cross-flow fan unit, a step for varying the passage area may be formed in a passage on the downstream side of the fan in the fluid flow direction. In this case, sound waves may be reflected by the step and resonate in the passage, resulting in noise. Noise caused by resonance in the passage due to reflection of sound waves by such a step cannot be effectively suppressed simply by arranging a Helmholtz resonator near the fan. <00T00026>

[0005] An object of the present disclosure is to suppress noise in a cross-flow fan unit.

Means for Solving the Problems

[0006] A first aspect of this disclosure relates to a cross-flow fan unit (10). The cross-flow fan unit (10) comprises a cross-flow fan (20) and a casing (30) housing the fan (20). The casing (30) has a first passage (40) located downstream (Fb) of the fan (20) in the fluid (A) flow direction (F), and a second passage (60) located downstream (Fb) of the first passage (40) in the flow direction (F) and having a larger passage area (S) than the first passage (40). A step (71) is formed at the boundary (70) between the first passage (40) and the second passage (60). The casing (30) is provided with a hollow structure (80) having a space (E) formed inside (81). The wall portion (40a) constituting the first passage (40) is provided with an opening (82) that communicates with the space (E).

[0007] According to the first embodiment, a step (71) is formed at the boundary (70) between the first passage (40) and the second passage (60) to vary the passage area (S). Sound waves may resonate in the second passage (60) when they reflect off the step (71), potentially generating noise.

[0008] Therefore, an opening (82) is provided in the wall portion (40a) of the first passage (40) located near the second passage (60), which communicates with the space (E) inside (81) of the hollow structure (80). The hollow structure (80) functions as a Helmholtz resonator.

[0009] Resonance in the second passage (60) due to sound wave reflection at the step (71) can be suppressed. As a result, noise can be suppressed in the cross-flow fan unit (10).

[0010] A second aspect of this disclosure relates to a cross-flow fan unit (10) according to the first aspect. In this cross-flow fan unit (10), the opening (82) faces the second passage (60).

[0011] According to the second embodiment, the noise suppression effect can be enhanced by positioning the opening (82) that communicates with the space (E) inside (81) of the hollow structure (80) facing the second passage (60), which is a noise source.

[0012] A third aspect of this disclosure relates to a cross-flow fan unit (10) according to the first or second aspect. In this cross-flow fan unit (10), the opening (82) is located downstream (Fb) of the central portion (44) of the wall portion (40a) in the flow direction (F).

[0013] According to the third embodiment, the noise suppression effect can be enhanced by bringing the opening (82) that communicates with the space (E) inside (81) of the hollow structure (80) closer to the second passage (60), which is a noise source.

[0014] A fourth aspect of this disclosure relates to a cross-flow fan unit (10) according to any one of the first to third aspects. In this cross-flow fan unit (10), the opening (82) is not located upstream (Fa) of the central portion (44) of the wall portion (40a) in the flow direction (F).

[0015] According to the fourth embodiment, by moving the opening (82) away from the fan (20), it is possible to suppress the flow of fluid (A) sent by the fan (20) into the opening (82).

[0016] A fifth aspect of the present disclosure relates to a cross-flow fan unit (10) according to any one of the first to fourth aspects. In this cross-flow fan unit (10), the casing (30) is provided with a tongue portion (50), the wall portion (40a) includes a first wall portion (41) located on the tongue portion (50) side when viewed in the axial direction (X) of the fan (20), and the opening (82) is provided in the first wall portion (41).

[0017] According to the fifth embodiment, the opening (82) can be suitably arranged.

[0018] The sixth aspect of the present disclosure is directed to the cross-flow fan unit (10) according to any one of the first to fifth aspects. In this cross-flow fan unit (10), the casing (30) is provided with a tongue portion (50), and the wall portion (40a) includes a second wall portion (42) on the side opposite to the tongue portion (50) when viewed in the axial direction (X) of the fan (20), and the opening (82) is provided in the second wall portion (42).

[0019] According to the sixth aspect, the opening (82) can be preferably arranged.

[0020] The seventh aspect of the present disclosure is directed to a utilization unit (3, 113). This utilization unit (3, 113) includes a cross-flow fan unit (10) according to any one of the first to sixth aspects and a heat exchanger (90) disposed in the second passage (60) in the cross-flow fan unit (10).

[0021] According to the seventh aspect, by arranging the heat exchanger (90) in the second passage (60) having a large through-sectional area (S), the layout of the heat exchanger (90) becomes easy.

[0022] The eighth aspect of the present disclosure is directed to an air conditioner (1, 111). This air conditioner (1, 111) includes a utilization unit (3, 113) according to the seventh aspect and a heat source unit (2, 112).

Brief Description of the Drawings

[0023] [Figure 1] FIG. 1 shows an air conditioner (1) according to the first embodiment. [Figure 2] FIG. 2 shows a cross-flow fan unit (10) according to the first embodiment. [Figure 3] FIG. 3 shows a fan (20) according to the first embodiment. [Figure 4] FIG. 4 shows the mechanism of noise generation in the cross-flow fan unit (10) according to the first embodiment. [Figure 5]FIG. 5 shows a hollow structure (80) according to the first embodiment. [Figure 6] FIG. 6 shows a hollow structure (80) according to the second embodiment. [Figure 7] FIG. 7 shows a hollow structure (80) according to the third embodiment. [Figure 8] FIG. 8 shows an air conditioner (111) according to the fourth embodiment.

Embodiments for Carrying Out the Invention

[0024] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below, and various modifications are possible without departing from the technical idea of the present disclosure. Since each drawing is for conceptually explaining the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for easy understanding.

[0025] <First Embodiment> (Air conditioner) The first embodiment will be described. FIG. 1 shows an air conditioner (1). The air conditioner (1) includes a water heater (2), a fan convector (3), and a hot water pipe (4). Since FIG. 1 is merely a conceptual diagram, the shapes and the like of the respective components may be different from those of other figures.

[0026] The water heater (2) is an example of a heat source unit. The water heater (2) is, for example, a gas water heater or an electric water heater. The water heater (2) heats water to make hot water (W) at a predetermined temperature. The water heater (2) is arranged outdoors (101).

[0027] The fan convector (3) is an example of a unit used. The fan convector (3) comprises a cross-flow fan unit (10) and a heat exchanger (90). The fan convector (3) is located inside a room (102). The room (102) has a floor (102a). The outside (101) and the inside (102) are separated by a wall (103). The fan convector (3) is mounted on the wall (103) on the inside (102) side. The fan convector (3) is a so-called wall-mounted type.

[0028] The hot water piping (4) is connected to the water heater (2) and the heat exchanger (90) of the fan convector (3). The hot water piping (4) penetrates the wall (103). The hot water piping (4) includes a supply pipe (4a) and a return pipe (4b). The supply pipe (4a) sends hot water (W) from the water heater (2) to the heat exchanger (90) of the fan convector (3). The return pipe (4b) returns the hot water (W) from the heat exchanger (90) of the fan convector (3) to the water heater (2).

[0029] In the fan convector (3), air (A) sent by the fan (20) described later in the cross-flow fan unit (10) passes through the heat exchanger (90). The air (A) exchanges heat with the hot water (W) flowing through the heat exchanger (90). The air (A) is heated and its temperature rises. The heated warm air (A) is sent to the room (102). The hot water (W) flowing through the heat exchanger (90) exchanges heat with the air (A). The hot water (W) is cooled and its temperature drops. The cooled hot water (W) is returned to the water heater (2) and heated again by the water heater (2).

[0030] (Cross-flow fan unit) Figure 2 shows a cross-sectional view of the cross-flow fan unit (10). Figure 3 shows the fan (20). The cross-flow fan unit (10) comprises the fan (20) and the casing (30). In the following description, using Figure 2 as a reference, the front of the page is referred to as the rear, the back of the page as the front, left as left, right as right, top as top, and bottom as bottom. Figure 2 is a cross-sectional view of the cross-flow fan unit (10) seen from the rear. The cross-flow fan unit (10) shown in Figure 1 is viewed from the front.

[0031] The fan (20) is a cross-flow fan. The fan (20) is formed in a roughly cylindrical shape. The axis (O) of the fan (20) extends in the front-rear direction. The direction in which the axis (O) extends is called the axial direction (X). The side away from the axis (O) is called the radial direction (R) outer circumference (Ro). The side approaching the axis (O) is called the radial direction (R) inner circumference (Ri). The direction of rotation around the axis (O) and the opposite direction are called the circumferential direction (T). In the drawing, an arrow is shown indicating the direction of rotation within the circumferential direction (T). The fan (20) is formed with its longitudinal side in the axial direction (X) and its shortened side in the radial direction (R).

[0032] The fan (20) has a plurality of partition plates (21), a plurality of blades (22), and two shafts (23). The partition plates (21) are roughly disc-shaped. The plurality of partition plates (21) are arranged side by side with spacing in the axial direction (X).

[0033] The blades (22) are stretched between the outer peripheries of adjacent partition plates (21) in the axial direction (X). Multiple blades (22) are arranged side by side with spacing in the circumferential direction (T). The blades (22) extend longitudinally in the axial direction (X) and transversely in the radial direction (R) and circumferential direction (T). Note that in Figure 2, the number of blades (22) is reduced for clarity.

[0034] The shaft portion (23) is located in the center of two partition plates (21) positioned at both ends in the axial direction (X). The shaft portion (23) protrudes outward from the partition plates (21) in the axial direction (X). One of the shaft portions (23) is connected to an electric motor (not shown). The other shaft portion (23) is supported by a support shaft portion (not shown) provided in the casing (30).

[0035] The casing (30) includes a fan housing (31), an intake port (32), an outlet passage (40), a tongue portion (50), a duct (60), and a hollow structure (80).

[0036] The fan housing section (31) of the casing (30) houses the fan (20). Within the fan housing section (31), the fan (20) extends in the axial direction (X) and rotates counterclockwise in the circumferential direction (T) (when viewed from the rear).

[0037] The intake port (32) is located to the left or below the outer periphery (Ro) of the fan housing (31). The intake port (32) opens to the left or downward.

[0038] The discharge passage (40) is an example of a first passage. The discharge passage (40) is located above the outer periphery (Ro) of the fan housing (31). The discharge passage (40) extends vertically. More specifically, the discharge passage (40) extends diagonally, moving to the left as it goes upwards. The lower end of the discharge passage (40) is connected to the fan housing (31). The upper end of the discharge passage (40) is connected to the duct (60) described later.

[0039] The cross-section perpendicular to the direction in which the discharge passage (40) extends is approximately rectangular. The discharge passage (40) is composed of four wall sections (40a). The wall sections (40a) that make up the discharge passage (40) include a left wall section (41), a right wall section (42), a rear wall section (not shown), and a front wall section (43). The left wall section (41) is an example of a first wall section. The right wall section (42) is an example of a second wall section.

[0040] The left wall (41) is positioned to the left and faces diagonally upward to the right. The right wall (42) is positioned to the right and faces diagonally downward to the left. The rear wall is positioned at the rear and faces forward. The front wall (43) is positioned at the front and faces rear. The left wall (41) and the right wall (42) face each other diagonally in the left-right and up-down directions. The rear wall and the front wall (43) face each other in the front-back direction. The right wall (42) has a spiral volute shape when viewed in the axial direction (X) and is also called the back scroll.

[0041] The tongue portion (50) is provided between the fan housing portion (31) and the discharge passage (40) in the casing (30). The tongue portion (50) is positioned between the upper end of the fan housing portion (31) and the lower end of the left wall portion (41) of the discharge passage (40). The tongue portion (50) has a tongue-like shape that protrudes diagonally downward to the right. The tongue portion (50) is the starting point of a spiral volute between the fan housing portion (31) and the discharge passage (40).

[0042] The left wall portion (41) of the air outlet passage (40) is on the tongue portion (50) side when viewed in the axial direction (X) of the fan (20). The right wall portion (42) of the air outlet passage (40) is on the opposite side from the tongue portion (50) when viewed in the axial direction (X) of the fan (20).

[0043] The duct (60) is an example of a second passage. The duct (60) is located above the outer periphery (Ro) of the discharge passage (40). The duct (60) extends vertically. The lower end of the duct (60) is connected to the upper end of the discharge passage (40). An outlet (64) is provided at the upper end of the duct (60).

[0044] The cross-section of the duct (60) perpendicular to the direction in which it extends is approximately rectangular. The duct (60) is composed of four wall sections (60a). The wall sections (60a) that make up the duct (60) include a left wall section (61), a right wall section (62), a rear wall section (not shown), and a front wall section (63).

[0045] The left wall section (61) is positioned to the left and faces to the right. The right wall section (62) is positioned to the right and faces to the left. The rear wall section is positioned at the rear and faces forward. The front wall section (63) is positioned at the front and faces rear. The left wall section (61) and the right wall section (62) face each other from left to right. The rear wall section and the front wall section (63) face each other from front to back.

[0046] The duct (60) has a larger passage area (S) than the discharge passage (40). The discharge passage (40) has a first passage area (S1) as the passage area (S). The first passage area (S1) is the area of ​​the cross-section perpendicular to the direction in which the discharge passage (40) extends. The duct (60) has a second passage area (S2) as the passage area (S). The second passage area (S2) is the area of ​​the cross-section perpendicular to the direction in which the duct (60) extends. The second passage area (S2) of the duct (60) is larger than the first passage area (S1) of the discharge passage (40).

[0047] The duct (60) has a greater left-right passage width (H) than the discharge passage (40). The discharge passage (40) has a first passage width (H1) as its passage width (H). The first passage width (H1) is the left-right width of the discharge passage (40). The duct (60) has a second passage width (H2) as its passage width (H). The second passage width (H2) is the left-right width of the duct (60). The second passage width (H2) of the duct (60) is greater than the first passage width (H1) of the discharge passage (40).

[0048] The lower end of the left wall portion (61) of the duct (60) is in almost the same position in the left-right direction as the upper end of the left wall portion (41) of the discharge passage (40) (in this example, this portion is the opening (82) described later). The lower end of the right wall portion (62) of the duct (60) is positioned to the right (protruding to the right) of the upper end of the right wall portion (42) of the discharge passage (40) when viewed in the axial direction (X).

[0049] A step (71) is formed at the boundary (70) between the discharge passage (40) and the duct (60). The step (71) connects the upper end of the right wall (42) of the discharge passage (40) and the lower end of the right wall (62) of the duct (60). The step (71) extends to the left and right. The step (71) faces the discharge outlet (64) of the duct (60).

[0050] A heat exchanger (90) is located in the duct (60) of the casing (30) of the cross-flow fan unit (10). The heat exchanger (90) is, for example, a fin-and-tube type. Hot water piping (4) is connected to the heat exchanger (90) (see Figure 1). In this example, the heat exchanger (90) is large and cannot be accommodated in the discharge passage (40), but it can be accommodated in the duct (60).

[0051] (Airflow) This section describes the flow of air (A) in the cross-flow fan unit (10). Air (A) is an example of a fluid. In the following description, the direction in which air (A) flows is referred to as the flow direction (F). The upstream side of the flow direction (F) is sometimes simply called the upstream side (Fa). The downstream side of the flow direction (F) is sometimes simply called the downstream side (Fb).

[0052] Air (A) flows into the fan housing (31) through the intake port (32). At this time, the air (A) flows from left to right, or from bottom to top. In the fan housing (31), the direction of flow (F) of the air (A) is changed by the fan (20) so that it flows from bottom to top and flows into the discharge passage (40). The flow of air (A) becomes swirling at the tongue (50) between the fan housing (31) (fan (20)) and the discharge passage (40).

[0053] Air (A) flows from bottom to top through the discharge passage (40) (more specifically from diagonally lower right to diagonally upper left) and into the duct (60). As air (A) flows from bottom to top through the duct (60), it passes through the heat exchanger (90). Air (A) is heated and its temperature rises through heat exchange with the hot water (W) flowing through the heat exchanger (90). Air (A) is then blown out into the room (102) through the outlet (64) of the duct (60).

[0054] The discharge passage (40) is located downstream (Fb) of the fan (20) (housed in the fan housing (31)) in the direction (F) of air (A). The tongue portion (50) is located between the fan (20) and the discharge passage (40) in the direction (F) of air (A) (downstream (Fb) of the fan (20) and upstream (Fa) of the discharge passage (40). The duct (60) is located downstream (Fb) of the discharge passage (40) in the direction (F) of air (A).

[0055] (noise) Figure 4 shows the mechanism of noise generation in the cross-flow fan unit (10). In the cross-flow fan unit (10), a step (71) is formed at the boundary (70) between the discharge passage (40) and the duct (60) downstream (Fb) of the fan (20) in the direction (F) of air flow (A), in order to change the passage area (S).

[0056] Sound waves (P) resonate in the duct (60) due to reflection off the step (71), resulting in noise. For example, the sound waves (P) become standing waves in the duct (60). Noise caused by resonance in the duct (60) due to the reflection of sound waves (P) at the step (71) cannot be effectively suppressed by simply placing a Helmholtz resonator near the fan (20).

[0057] (Hollow structure) Figure 5 shows the hollow structure (80). The hollow structure (80) functions as a Helmholtz resonator. In a Helmholtz resonator, the air inside a hollow container with an opening acts as a spring and resonates. This resonance of air absorbs sound energy, resulting in sound dampening.

[0058] The hollow structure (80) is provided in the casing (30). More specifically, the hollow structure (80) is provided to the left of the discharge passage (40) in the casing (30). The hollow structure (80) has a space (E) formed inside (81). Air is contained in the space (E).

[0059] An opening (82) is provided in the wall portion (40a) that constitutes the discharge passage (40). More specifically, the opening (82) is provided in the left wall portion (41) of the wall portion (40a) that constitutes the discharge passage (40).

[0060] The opening (82) communicates with the space (E) inside (81) of the hollow structure (80).

[0061] The opening (82) faces diagonally upward to the right. At least a portion of the opening (82) faces the duct (60). In this example, the entire opening (82) faces the duct (60). A straight line (L) extending vertically from at least a portion of the opening (82) intersects a cross-section perpendicular to the vertical direction in which the duct (60) extends.

[0062] The opening (82) is located downstream (Fb) of the central portion (44) in the flow direction (F) of the left wall portion (41) (wall portion (40a)). More specifically, the entire opening (82) is located downstream (Fb) of the central portion (44) in the flow direction (F) of the left wall portion (41) (wall portion (40a)). The opening (82) is not located upstream (Fa) of the central portion (44) in the flow direction (F) of the left wall portion (41) (wall portion (40a)). The central portion (44) is the midpoint between the tongue portion (50) and the boundary portion (70).

[0063] (Effects and Benefits) A step (71) is formed at the boundary (70) between the discharge passage (40) and the duct (60) to vary the passage area (S). Sound waves (P) may resonate in the duct (60) when reflected off the step (71), potentially resulting in noise.

[0064] Therefore, an opening (82) is provided in the wall portion (40a) (left wall portion (41)) that constitutes the discharge passage (40) near the duct (60), which communicates with the space (E) inside (81) of the hollow structure (80). The hollow structure (80) functions as a Helmholtz resonator.

[0065] Resonance in the duct (60) due to the reflection of sound waves (P) at the step (71) can be suppressed. As a result, noise can be suppressed in the cross-flow fan unit (10).

[0066] By positioning the opening (82) that communicates with the space (E) inside (81) of the hollow structure (80) facing the duct (60), which is the source of the noise, the noise suppression effect can be enhanced.

[0067] The opening (82) is located downstream (Fb) of the central part (44) in the flow direction (F) of the wall section (40a) (left wall section (41)). By bringing the opening (82), which communicates with the space (E) inside (81) of the hollow structure (80), closer to the duct (60), which is the noise source, the noise suppression effect can be enhanced.

[0068] The opening (82) is not located upstream (Fa) of the central part (44) in the flow direction (F) of the wall (40a) (left wall (41)). By moving the opening (82) away from the fan (20), it is possible to suppress the flow of air (A) supplied by the fan (20) into the opening (82).

[0069] The opening (82) is provided in the left wall portion (41) on the tongue portion (50) side. The opening (82) can be positioned appropriately. Furthermore, it becomes easier to position the opening (82) facing the duct (60).

[0070] By placing the heat exchanger (90) in a duct (60) with a large passage area (S), the layout of the heat exchanger (90) becomes easier.

[0071] <Second Embodiment> A second embodiment will now be described. In the following description, components similar to those in the above embodiment will be denoted by the same reference numerals, and detailed descriptions will be omitted. Figure 6 shows the hollow structure (80).

[0072] The hollow structure (80) is located to the right of the discharge passage (40) in the casing (30). The opening (82) is located in the right wall portion (42) of the wall portion (40a) that constitutes the discharge passage (40). The right wall portion (42) is located on the opposite side from the tongue portion (50) when viewed in the axial direction (X) of the fan (20).

[0073] The other configurations are the same as in the first embodiment.

[0074] The opening (82) can be positioned appropriately.

[0075] <Third Embodiment> A third embodiment will now be described. In the following description, components similar to those in the above embodiments will be denoted by the same reference numerals, and detailed descriptions will be omitted. Figure 7 shows the hollow structure (80).

[0076] The hollow structure (80) is provided to the left of the discharge passage (40) in the casing (30). The hollow structure (80) is provided to the right of the discharge passage (40) in the casing (30). The opening (82) is provided in the left wall portion (41) of the wall portion (40a) that constitutes the discharge passage (40). The opening (82) is provided in the right wall portion (42) of the wall portion (40a) that constitutes the discharge passage (40).

[0077] The other configurations are the same as those of the first and second embodiments.

[0078] An opening (82) communicating with the space (E) inside (81) of the hollow structure (80) is provided on both the left wall (41) on the tongue-shaped portion (50) side and the right wall (42) on the opposite side of the tongue-shaped portion (50). This is advantageous in enhancing the noise suppression effect.

[0079] <Fourth Embodiment> A fourth embodiment will now be described. In the following description, components similar to those in the above embodiments will be denoted by the same reference numerals, and detailed explanations will be omitted. Figure 8 shows an air conditioning system (111). Figure 8 is merely a conceptual diagram, and the shapes of each component may differ from those in the other figures.

[0080] The air conditioning system (111) comprises an outdoor unit (112) and an indoor unit (113). The outdoor unit (112) is an example of a heat source unit. The indoor unit (113) is an example of a utilization unit.

[0081] The outdoor unit (112) comprises a compressor (114), an outdoor heat exchanger (115), and a pressure reducing mechanism (116). The pressure reducing mechanism (116) includes an expansion valve and a capillary tube. The indoor unit (113) comprises a cross-flow fan unit (10) and an indoor heat exchanger (90).

[0082] The compressor (114), the outdoor heat exchanger (115), the pressure reducing mechanism (116), and the indoor heat exchanger (90) constitute a refrigerant circuit (111a) through which the refrigerant (C) circulates. The refrigerant circuit (111a) performs, for example, a vapor compression type refrigeration cycle. The air (A) blown by the cross-flow fan unit (10) undergoes heat exchange with the refrigerant (C) as it passes through the indoor heat exchanger (90), and is then sent into the room.

[0083] <Other Embodiments> In the casing (30), the discharge passage (40) and the duct (60) may be formed as a single unit or as separate components.

[0084] The cross-sections of the discharge passage (40) and the duct (60) are not limited to a roughly rectangular shape, but may be circular, for example.

[0085] The fluid (A) is not limited to air.

[0086] The fan convector (3) may be placed on the floor (102a) (it may be a so-called floor-standing type).

[0087] Although embodiments have been described above, it will be understood that various modifications to the form and details are possible without departing from the spirit and scope of the claims. The above embodiments, modifications, and elements of other embodiments may be combined or substituted as appropriate.

[0088] The designations "1st," "2nd," "3rd," etc., mentioned above are used to distinguish between the terms to which these designations are attached, and do not limit the number or order of those terms. [Explanation of symbols]

[0089] X-axis direction F flow direction Fa upstream side Fb downstream side S aisle area A. Air (fluid) P sound waves E space 1. Air conditioning system 2. Water heater (heat source unit) 3. Fan Convector (Usage Unit) 10 Cross-flow fan units 20 Fans 30 Casing 40 Outlet passage (1st passage) 40a wall 41 Left wall section (first wall section) 42 Right wall section (second wall section) 44 Central part 50 Tongue 60 Duct (Second Passage) 70 Boundary 71 steps 80 Hollow structure 81 Inside 82 Aperture 90 Heat exchanger 111 Air conditioning system 112 Outdoor unit (heat source unit) 113 Indoor unit (used unit)

Claims

1. Cross-flow type fan (20), The fan (20) is housed in a casing (30), The casing (30) is A first passage (40) is located downstream (Fb) of the fan (20) in the flow direction (F) of the fluid (A), The system includes a second passage (60) located downstream (Fb) of the first passage (40) in the flow direction (F) and having a larger passage area (S) than the first passage (40), A step (71) is formed at the boundary (70) between the first passage (40) and the second passage (60). The casing (30) is provided with a hollow structure (80) in which a space (E) is formed inside (81). A cross-flow fan unit is provided in which an opening (82) communicating with the space (E) is provided in the wall portion (40a) that constitutes the first passage (40).

2. The cross-flow fan unit according to claim 1, wherein the opening (82) faces the second passage (60).

3. The cross-flow fan unit according to claim 1 or 2, wherein the opening (82) is located downstream (Fb) of the central portion (44) in the flow direction (F) of the wall portion (40a).

4. The cross-flow fan unit according to claim 1 or 2, wherein the opening (82) is not located upstream (Fa) of the central portion (44) in the flow direction (F) of the wall portion (40a).

5. The casing (30) is provided with a tongue portion (50), The wall portion (40a) includes a first wall portion (41) located on the tongue portion (50) side when viewed in the axial direction (X) of the fan (20), The cross-flow fan unit according to claim 1 or 2, wherein the opening (82) is provided in the first wall portion (41).

6. The casing (30) is provided with a tongue portion (50), The wall portion (40a) includes a second wall portion (42) that is on the opposite side from the tongue portion (50) when viewed in the axial direction (X) of the fan (20), The cross-flow fan unit according to claim 1 or 2, wherein the opening (82) is provided in the second wall portion (42).

7. A cross-flow fan unit (10) according to claim 1 or 2, A utilization unit comprising a heat exchanger (90) disposed in the second passage (60) of the cross-flow fan unit (10).

8. The utilization unit (3,113) described in claim 7, An air conditioning system comprising a heat source unit (2,112).

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