TWI623715B - Air conditioner - Google Patents

Abstract

An object of the present invention is to provide an air conditioner that can stably supply air even under the operating conditions where the ventilation resistance of an air duct becomes large, such as when dust is accumulated on an air filter or a heat exchanger.

The air conditioner (100) for solving the problem is an indoor unit (2). The air conditioner (100) includes a cross flow fan (9) configured by axially connecting a plurality of fan elements, and a cross flow fan (9) arranged along the axial direction of the cross flow fan (9). The front nose (28), the opposite surface (28Aa ~ 28Ca) opposite to the crossflow fan (9) of the front nose (28) is on both ends of the crossflow fan (9), and has a crossflow fan (9) The length of the peripheral direction is longer than the central portion of the crossflow fan (9). The projection (28Ce) is longer, and the area of the axial projection of the crossflow fan (9) is wide (W). When the diameter is (D), 0.08 ≦ W / D ≦ 0.32 is satisfied.

Description

air conditioner

The present invention relates to an air conditioner.

An example of the structure of an indoor unit provided in a conventional air conditioner is shown in FIG. 2 of Patent Document 1 (Japanese Patent Application Laid-Open No. 2009-127875). The indoor unit of the air conditioner is constituted by housing an indoor heat exchanger, a cross-flow fan, an air filter, and the like inside the housing of the indoor unit in which the inlet and the outlet are formed. In addition, a front nose portion and a rear nose portion are arranged around the cross-flow fan so that the suction port and the blowing port are separated. In addition, the length of the rotation axis direction (left-right direction) of the cross-flow fan is limited, and the left and right side walls restrict the air duct.

When the cross-flow fan rotates, as shown in FIG. 8 of Patent Document 1, a circulating vortex is generated inside the cross-flow fan. The negative pressure of the circulating vortex draws indoor air from the suction port, and the indoor air drawn by the indoor heat exchanger and Heat exchange is performed between the refrigerants to generate conditioned air, and the conditioned air is drawn from the air outlet to perform indoor air conditioning.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2009-127875

[Invention Summary]

As described above, the cross-flow fan supplies air by circulating vortexes generated inside the cross-flow fan during operation, but the side wall portion is disturbed by the influence of wall surface friction and becomes unstable. In addition, in the portion where the motor shaft and the hub for the cross-flow fan are combined, the ventilation resistance inside the cross-flow fan increases, and the air supply is liable to become unstable.

Due to these factors, with the use of the air conditioner, if the air filter or heat exchanger of the air conditioner accumulates dust, and the ventilation resistance of the air duct becomes large, the shaft from the cross flow fan will be lost. The air supply to the end is stable, and there is a sound such as a flutter and a so-called surge phenomenon caused by backflow.

Therefore, the present invention has an object to provide an air conditioner that can stably supply air even under the operating conditions where the ventilation resistance of an air duct becomes large even when dust is accumulated on an air filter or a heat exchanger.

In order to solve the above-mentioned problems, the air conditioner according to the present invention is an indoor unit, and includes a cross flow in which a plurality of fan elements are axially connected. The fan and the front nose portion arranged along the axial direction of the cross-flow fan are characterized in that the opposite sides opposite to the cross-flow fan of the front nose are at both ends of the cross-flow fan and have the above-mentioned features. The length of the cross-flow fan in the circumferential direction is longer than the central portion of the cross-flow fan. The width W of the cross-section fan in the axial direction of the projection is formed when the diameter of the cross-flow fan is D. Meet 0.08 ≦ W / D ≦ 0.32.

According to the present invention, it is possible to provide an air conditioner that can stably supply air even under the operating conditions in which dust is accumulated on an air filter or a heat exchanger and the ventilation resistance of the air duct is increased.

1‧‧‧ outdoor unit

2‧‧‧ indoor unit

3‧‧‧compressor

4‧‧‧ four-way valve

5‧‧‧ outdoor heat exchanger

6‧‧‧ spiral fan

7‧‧‧Expansion valve

8‧‧‧ indoor heat exchanger

9‧‧‧ Cross Flow Fan

9a‧‧‧End plate

9b‧‧‧axis

9c‧‧‧fan element

9d‧‧‧fan element

9e‧‧‧End plate

9f‧‧‧ Wheel

10‧‧‧Piping

11‧‧‧Indoor fan motor

11a‧‧‧Motor shaft

12‧‧‧ set screw

20‧‧‧Indoor unit frame

21‧‧‧Indoor unit frame

22‧‧‧Front wing

23‧‧‧Suction port

24‧‧‧air filter

25‧‧‧air filter frame

26‧‧‧ Blow Out

27‧‧‧ Up and down wind direction control panel

28, 28A, 28B, 28C ‧‧‧ front nose

28Aa, 28Ba, 28Ca‧‧‧ facing

28Ab, 28Bb, 28Cb

28Ac, 28Bc, 28Cc ‧‧‧ connecting surface

28Cd‧‧‧Base

28Ce‧‧‧ protrusion

28Cf, 28Cg ‧‧‧ side

29‧‧‧ front case

30‧‧‧ rear nose

31‧‧‧ rear case

32‧‧‧ sidewall

33‧‧‧Electric component box

100‧‧‧ Air Conditioner

F‧‧‧Spit Out

S‧‧‧ opening

FIG. 1 is a configuration diagram of an air conditioner according to this embodiment.

FIG. 2 is a diagram showing that an indoor unit of an air conditioner according to the present embodiment includes a cross flow fan and an indoor fan motor.

Fig. 3 is a cross-sectional view of an air conditioner including an indoor unit according to the embodiment.

Fig. 4 is a bottom view of the air conditioner according to the embodiment including an indoor unit.

Fig. 5 is a side cross-sectional view and a streamline diagram near the blow-out port of the indoor unit in the A-A cross section.

Fig. 6 is a side cross-sectional view near the blow-out port of the indoor unit in the B-B cross section And streamline diagram.

Fig. 7 is a side cross-sectional view and a streamline diagram near the blow-out port of the indoor unit of the C-C cross section.

Fig. 8 is a perspective view showing the shape of the nose portion before being displayed from the axial center side of the cross flow fan.

Fig. 9 is a perspective view of a component including a nose portion before both ends.

Fig. 10 is a characteristic diagram showing an example of the relationship between the air volume and the static pressure of the cross-flow fan.

FIG. 11 is a graph illustrating the relationship between the reduction area of the blowing wind speed and W / D.

Fig. 12 (a) is a schematic diagram of the air duct of the indoor unit, and Fig. 12 (b) is a diagram showing the wind speed distribution of the air outlet of the indoor unit.

FIG. 13 is a diagram illustrating the characteristics of the cross-flow fan according to this embodiment and a conventional example.

Fig. 14 is a diagram comparing the fan input of the air conditioner of this embodiment and the conventional example.

FIG. 15 is a graph showing the maximum fluctuation value of the rotation speed of the cross flow fan when the static pressure at the inlet increases in the air conditioner of this embodiment and the conventional example.

Hereinafter, the form for implementing this invention (henceforth "embodiment") is demonstrated in detail, referring an illustration suitably. In addition, in the drawings, common parts are given the same reference numerals, and redundant descriptions are omitted.

《Air Conditioner 100》

The air conditioner 100 according to this embodiment will be described using FIG. 1. FIG. 1 is a schematic configuration diagram of the air conditioner 100 according to the embodiment.

As shown in FIG. 1, the air conditioner 100 according to the present embodiment includes an outdoor unit 1 and an indoor unit 2. The outdoor unit 1 includes a compressor 3 for compressing the refrigerant, a four-way valve 4 for switching the flow direction of the refrigerant, an outdoor heat exchanger 5 for exchanging heat between the refrigerant and outdoor air, and a device for drawing outdoor air into the outdoor unit 1. An internal spiral fan 6 and an expansion valve 7 for expanding the refrigerant. The indoor unit 2 includes an indoor heat exchanger 8 for heat exchange between the refrigerant and the indoor air, and a cross-flow fan 9 for sucking indoor air into the interior of the indoor unit 2. In addition, the compressor 3, the four-way valve 4, the outdoor heat exchanger 5, the expansion valve 7, and the indoor heat exchanger 8 are connected by a pipe 10, and the refrigerant can be circulated. The refrigerant may be a refrigerant such as R410A or R32.

When the cold room of the air conditioner 100 is operating, the four-way valve 4 is connected as shown by the solid line in FIG. 1, and the refrigerant discharged from the compressor 3 is in the order of the outdoor heat exchanger 5, the expansion valve 7, and the indoor heat exchanger 8. Flow and circulate again to compressor 3 (see the solid arrow in Figure 1). On the other hand, in the warm room operation of the air conditioner 100, the four-way valve 4 is connected as indicated by the dotted line in FIG. 5 flows in sequence and circulates to compressor 3 again (see the dotted arrow in Fig. 1).

The outdoor air is sucked into the outdoor unit 1 by the spiral fan 6 (see the thick solid arrow in FIG. 1). The inside of the outdoor unit 1 passes through the outdoor heat exchanger 5 through the sucked outdoor air, so that heat can be exchanged between the refrigerant and the outdoor air. In addition, the indoor air is drawn into the interior of the indoor unit 2 by the cross-flow fan 9 (see the thick solid line arrows in FIG. 1). The inside of the indoor unit 2 passes the indoor heat exchanger 8 through the sucked indoor air, so that heat can be exchanged between the refrigerant and the indoor air. Then, the conditioned air of the heated or cooled indoor air is blown out from the indoor unit 2 into the room by heat exchange with the refrigerant, thereby performing indoor air conditioning.

FIG. 2 is a diagram showing that the indoor unit 2 of the air conditioner 100 according to this embodiment includes a cross flow fan 9 and an indoor fan motor 11. FIG. 2 is a diagram showing a direction (radial direction of the cross-flow fan 9) perpendicular to the axial direction (left-right direction) of the cross-flow fan 9.

As shown in Fig. 2, the cross-flow fan 9 is composed of: one end plate 9a; a shaft 9b provided on the end plate 9; a plurality of fan elements 9c; a fan element 9d; the other end plate 9e; 9e consists of a hub 9f. Incidentally, the number of fan elements of the cross-flow fan 9 of this embodiment is composed of a total of nine fan elements 9c (a part is omitted in the second figure) and one fan element 9d.

A motor shaft 11 a of the indoor fan 11 is inserted into a hub 9 f of the cross-flow fan 9, and is fastened with a fixing screw 12. In addition, the fan element 9d is disposed adjacent to the end plate 9e. A hub 9f is disposed at the center of the shaft. When the hub 9f and the motor shaft 11a are fastened with the set screw 12, a part of the fan fin can be detached by inserting a tool Point and fan components 9c is different.

FIG. 3 is a cross-sectional view of the air conditioner 100 according to the embodiment including the indoor unit 2. In addition, FIG. 3 is a cross-sectional view showing a surface that is perpendicular to the axis of the cross-flow fan 9 and is approximately the center of the axial length of the cross-flow fan 9 (see the A-A cross-sectional view of FIG. 4 described later). In addition, in FIG. 3, the front and back and up and down directions indicate the front and back direction and the up and down direction of the indoor unit 2. The same applies to FIGS. 5 to 7 to be described later.

As shown in FIG. 3, the indoor unit 2 is configured by including an indoor heat exchanger 8 and a cross-flow fan 9 in a space surrounded by the indoor unit housing 20 and the indoor unit housing 21. In addition, the indoor heat exchanger 8 is a so-called cross-fin type heat exchanger in which a plurality of aluminum fins are passed through the heat transfer tubes. The cross-flow fan 9 is rotated clockwise in FIG. 3. A front flap 22 is disposed on the front side of the indoor unit housing 20.

An air cleaner 24 is provided on the upstream inlet 23 of the indoor heat exchanger 8 to prevent dust from entering the interior of the indoor unit 2. The air cleaner 24 is supported by an air cleaner frame 25. Further, an up-and-down airflow direction control board 27 is arranged at the blow-out port 26 on the downstream side of the cross-flow fan 9.

A front nose portion 28 is formed in the indoor unit housing 20 so as to face the cross-flow fan 9 and separate the downstream side and the upstream side of the cross-flow fan 9. Further, a front case 29 is formed on the downstream side of the front nose portion 28 to constitute an air duct on the downstream side of the cross-flow fan 9. On the other hand, a rear nose 30 is formed in the indoor unit housing 21 so as to face the cross-flow fan 9 and separate the downstream side and the upstream side of the cross-flow fan 9. A rear case 31 is formed on the downstream side of the rear nose 30 to form an air duct on the downstream side of the cross-flow fan 9.

The indoor air is sucked into the inside of the indoor unit 2 from the suction port 23 above the indoor unit 2 by the flow of air generated by the rotation of the cross-flow fan 9. After passing through the air filter 24, the sucked air is heated or cooled by the indoor heat exchanger 8, and passes through the cross-flow fan 9 through the air duct formed by the front case 29 and the rear case 31, and is discharged from the indoor unit 2 The lower outlet 26 is supplied into the room. This allows air conditioning in the room.

<Front Nose 28>

Next, the shape of the front nose portion 28 of the air conditioner 100 according to this embodiment will be further described with reference to FIG. 4. FIG. 4 is a bottom view of the air conditioner 100 including the indoor unit 2 according to this embodiment.

As shown in FIG. 4, the shape of the front nose portion 28 is different depending on the axial position (left-right direction) of the cross-flow fan 9. Hereinafter, the shape (cross-sectional shape) of the nose portion 28 before each position will be further described using FIGS. 5 to 7.

Fig. 5 is a side cross-sectional view and a streamline diagram of the vicinity of the air outlet 26 of the indoor unit 2 in the A-A section (hereinafter, referred to as the first central portion) of Fig. 4.

As shown in FIG. 5, the front nose portion 28A of the first central portion includes an opposing surface 28Aa facing the cross-flow fan 9, an air channel surface 28Ab provided on the air channel side, and a connection surface 28Ac.

The opposing surface 28Aa is a surface opposed to the cross-flow fan 9, in other words, a surface closest to the cross-flow fan 9 at the front nose portion 28A. The air duct surface 28Ab is a surface opposed to the rear case 31, and the downstream side and the front of the indoor unit housing 20 The case 29 is connected. The connecting surface 28Ac is an arc-shaped curved surface connecting the opposing surface 28Aa and the air duct surface 28Ab.

Here, the opposing surface 28Aa of the first central portion is configured as a plane. In other words, the cross-section is substantially linear as shown in FIG. 5. With the shape as described above, it is possible to reduce interference with the cross-flow fan 9 and reduce noise.

Fig. 6 is a side sectional view and a streamline diagram of the vicinity of the outlet 26 of the indoor unit 2 in a B-B cross section (hereinafter, referred to as a second central portion) of Fig. 4.

As shown in FIG. 6, the front nose portion 28B of the second central portion includes an opposing surface 28Ba facing the cross-flow fan 9, an air duct surface 28Bb provided on the air duct side, and a connection surface 28Bc.

The opposing surface 28Ba is a surface opposed to the cross-flow fan 9, in other words, a surface closest to the cross-flow fan 9 at the front nose portion 28B. The air duct surface 28Bb is a surface opposed to the rear case 31, and is connected to the front case 29 of the indoor unit housing 20 on the downstream side. The connecting surface 28Bc is an arc-shaped curved surface connecting the opposing surface 28Ba and the air duct surface 28Bb.

Here, the opposing surface 28Ba of the second central portion is formed as a curved surface, and a circulating vortex flow generated along the inside of the cross-flow fan 9 during operation. Specifically, the cross-section is formed in a circular arc shape with the axis of the cross-flow fan 9 as the center as shown in FIG. 6. In other words, the opposing surface 28Ba of the cross-flow fan 9 and the front nose portion 28B is in a concentric circle relationship. The opposing surface 28Ba opposed to the cross-flow fan 9 is formed in a curved surface, whereby the flow can be stabilized along the shape (oval shape) of the circulating vortex. In addition, let the opposing surface 28Ba The shape of the concentric circle with the cross-flow fan 9 makes the front nose portion 28B close to the circulating vortex, which can stabilize the flow.

Fig. 7 is a side sectional view and a streamline diagram of the vicinity of the blowout port 26 of the indoor unit 2 in a C-C cross section (hereinafter, referred to as both end portions) in Fig. 2.

As shown in FIG. 7, the front nose portions 28C at both ends include an opposing surface 28Ca opposite to the cross-flow fan 9, an air channel surface 28Cb provided on the air channel side, and a connection surface 28Cc.

The opposing surface 28Ca is a surface opposed to the cross-flow fan 9, in other words, a surface closest to the cross-flow fan 9 at the front nose portion 28C. The air duct surface 28Cb is a surface opposed to the rear case 31 and is connected to the front nose portion 29 of the indoor unit casing 20 on the downstream side. The connecting surface 28Cc is an arc-shaped curved surface connecting the opposing surface 28Ca and the air duct surface 28Cb.

Here, the opposing surface 28Ca at both end portions is the same as the opposing surface 28Ba (see FIG. 6), and is formed by a curved surface, and flows along a circulating vortex generated inside the cross-flow fan 9 during operation. Specifically, its cross section is formed in a circular arc shape with the axis of the cross flow fan 9 as the center as shown in FIG. 7. In other words, the opposing surface 28Ca of the cross-flow fan 9 and the front nose portion 28C is in a concentric circle relationship. The opposing surface 28Ca opposed to the cross-flow fan 9 is formed by a curved surface, whereby the flow can be stabilized along the shape (oval shape) of the circulating vortex. In addition, the opposing surface 28Ca and the cross-flow fan 9 are formed in a concentric circle shape, so that the front nose portion 28C approaches the circulating vortex, and the flow can be more stabilized.

In addition, the opposing surface 28Ca at both end portions constitutes the opposing surface 28Aa or the opposing surface of the second central portion with the length in the peripheral direction. In comparison with 28Ba, the direction opposite to the rotation direction (clockwise direction in FIG. 7) of the cross-flow fan 9 becomes longer (counterclockwise direction in FIG. 7). In other words, the opposing surface 28Ca is a discharge opening F constituting the cross-flow fan 9 toward the blowing air duct (the air duct formed by the front nose portion 29 and the rear case 31), and is narrower than the opposing surface 28Aa or the opposing surface 28Ba.

Here, as compared with the central part (the first central part and the second central part), the frictional resistance of the wall surface or the influence of the hub 9f of the cross-flow fan 9 or the fixing screw 12 has a large ventilation resistance. There is no static pressure in the vicinity of 28 and the outlet 26. Therefore, the circulating vortex formed near the front nose portion 28 becomes larger at both ends (see Fig. 7) than at the center (see Figs. 5 and 6), and the wind velocity from the outlet 26 becomes slower. The susceptibility to countercurrent is also generally known.

In response to the problems described above, the air conditioner 100 according to the present invention is configured at both end portions where the circulating eddy current becomes larger so that the peripheral direction of the opposing surface 28Ca is longer than the central portion, and the front nose portion is also at both end portions (near the side wall) A static pressure difference between the vicinity of 28 and the blowout port 26 can stabilize the flow of the circulating vortex and is difficult to generate a countercurrent. In addition, since the outlet F of the cross-flow fan 9 is narrowed, it also has the effect of blocking the backward flow and the effect of increasing the wind speed from the air outlet 26, which makes the generation of the backward flow more difficult.

The connecting surfaces 28Cc at both ends are arc-shaped, and the radius is smaller than the arc-shaped radii of the connecting surfaces 28Ac and 28Bc of the central portions (the first central portion and the second central portion). With the above shape, even if the front nose portion 28C is extended in the surrounding direction, the opening S of the air duct is not made too narrow, and the fan input caused by the shrinkage can be reduced. increase.

FIG. 8 is a perspective view showing the shape of the nose portion 28 before being displayed from the axial center side of the cross flow fan 9. In addition, in FIG. 8, the cross-flow fan 9 is in a detached state. The left, right, front, and up and down directions in FIG.

As shown in FIG. 8, the front nose portions 28C at both ends are connected to the side wall 32. In addition, the front nose portion 28 shown in FIG. 8 is a component that integrates the front nose portion 28B of the second central portion and the front nose portion 28C of both ends, and the front nose portion 28A of the first central portion is configured as In addition, these components constitute the front nose 28.

Fig. 9 is a perspective view of the component including the nose portion 28C before both ends.

In the front nose portion 28C at both ends, the peripheral direction length of the curved surface (opposing surface 28Ca, see FIG. 8) facing the cross-flow fan 9 is approximately proportionally longer from the center portion to the both end portions.

In other expressions, the front nose portion 28 is a front nose portion 28C at both ends, and includes a base having the same curved surface as the facing surface 28Ba (see FIG. 8) of the front nose portion 28B in the center portion. The part 28Cd and the protruding part 28Ce which protrudes from this base part 28Cd toward the discharge port F (refer FIG. 6) of the cross flow fan 9 are comprised.

The protruding portion 28Ce is shown from the axial center side of the cross flow fan 9 and has a side 28Cf and a side 28Cg. Here, the side 28Cg on the axial end side of the protruding portion 28Ce is closest to the side wall 32 (see FIG. 8). The extending direction of the side 28Cg is the same as that of the cross-flow fan 9. On the other hand, the extending direction of the axial center-side edge 28Cf of the protruding portion 28Ce is inclined with respect to the peripheral direction of the cross-flow fan 9, and the direction is opposite to the rotation direction of the cross-flow fan 9 (see FIG. 6). Counterclockwise), and extends in a direction in which the distance between the side 28Cf and the side 28Cg becomes shorter.

In other words, the protruding portion 28Ce is shown from the axial center side of the cross flow fan 9 and has a substantially triangular shape, and the narrower the forward (rear) width (the axial width of the cross flow fan 9) of the configuration becomes.

With the above configuration, the protruding portion 28Ce of the front nose portion 28C is near the side wall 32 (see FIG. 8) where the cyclic vortex flow becomes the most unstable, and the length of the protruding portion 28Ce in the peripheral direction can be increased to improve the flow. The stability. In addition, the axial length of the crossflow fan 9 is gradually restored (shortened) in the peripheral direction of the protruding portion 28Ce. The expansion of the outlet F of the crossflow fan 9 (see FIG. 6) is suppressed to suppress the ventilation resistance. The increase leads to deterioration of the input.

In addition, as shown in FIG. 9, the length in the peripheral direction of the opposite surface 28Ba (see FIG. 8) of the front nose 28B (the length in the peripheral direction of the base 28Cd of the front nose 28C) is LB. The length in the peripheral direction of the opposing surface 28Ca (see FIG. 8) is LC, and the length in the peripheral direction of the protrusion 28Ce of the front nose portion 28C is L (= LC-LB). The axial length (length from the side wall 32) of the protruding portion 28Ce of the front nose portion 28C is W.

Here, with respect to the diameter (fan diameter) D of the cross-flow fan 9 The relationship with the axial length W of the protruding portion 28Ce is described with reference to FIGS. 10 and 11. FIG. 10 is a characteristic diagram showing an example of the relationship between the air volume and the static pressure of the cross-flow fan 9.

In the example of FIG. 10, the solid line indicates the experimental results when the fan diameter D is 125 mm and the rotation speed is 900 rpm. The dotted line indicates a case where the fan diameter D is similarly reduced to 100 mm, and indicates the calculation result when the rotational speed is set at the same operating point as the solid line example (the rotational speed is 1220 rpm).

As shown in FIG. 10, when the diameter of the fan D is small (see the dotted line), the larger the diameter of the fan D (see the solid line), the smaller the static pressure difference from the operating point to the maximum static pressure point. This is because dust is accumulated on the air filter 24 (see FIG. 3) or the indoor heat exchanger 8 (see FIG. 3), and when the ventilation resistance is increased (the operating static pressure is increased), the fan diameter D becomes larger. The more likely it is to cause backflow. That is, as the fan diameter D becomes larger, the flow becomes unstable, and the area where the air volume on the wall surface side decreases becomes larger.

FIG. 11 is a graph illustrating the relationship between the reduction area of the blowing wind speed and W / D. In addition, FIG. 11 is used for explaining the area where the air volume is reduced on the side of the wall surface. It does not include the protruding portion 28Ce (see FIG. 9) of this embodiment, and the shape of the front nose portion 28 in the central portion reaches the side wall 32 (see (Figure 8) Experimental results of air conditioners. In the experimental conditions of the example in FIG. 11, the fan diameter D of the cross-flow fan 9 is 125 mm, and the rotation speed of the cross-flow fan 9 is 900 rpm.

As shown in FIG. 10, since the larger the diameter D of the fan, The wider the area where the flow is unstable (the area where the blowing wind speed decreases), the horizontal axis of the graph shown in FIG. 11 is the ratio of the distance W from the side wall 32 (see FIG. 8) to the fan diameter D of the cross-flow fan 9. W / D display. In addition, the vertical axis indicates the blowing wind speed.

■ (The four corners are blacked out.) The drawing shows the blowing wind speed, the area with small W / D (near the side wall 32, the wall surface side), the ventilation resistance of the indoor heat exchanger 8 or the air duct, and the friction resistance of the wall surface. Reduce the blowing wind speed from the center side.

In addition, the (circle blacked out) drawing is a distribution of wind speed when the ventilation resistance of the indoor heat exchanger 8 is reduced, in other words, when the resistance on the wall surface side has a strong influence. In addition, in FIG. 11, a graph showing four modes according to the ventilation resistance of the indoor heat exchanger 8 is shown. The lower the resistance, the higher the wind speed.

Due to the influence of the resistance on the wall surface side, the blow-out wind speed is extremely reduced until W / D <0.08. Therefore, in this region, the front nose 28 extends toward the surroundings, and the flow field can be stabilized. In addition, in the area where the blowing wind speed is slow, the increase in the ventilation resistance of the front nose portion 28 extending in the peripheral direction is reduced, and the minimum effect on energy saving can be suppressed.

In addition, until W / D ≦ 0.32, the wind speed is greatly reduced compared to the center side. Therefore, in this area, the stabilization of the air supply caused by the front nose portion 28 extending in the peripheral direction is very effective. On the other hand, in the case where W / D> 0.32, the effect of stabilizing the air supply is extended more than the effect of the front nose portion 28 extending in the peripheral direction on the energy-saving effect of increasing the ventilation resistance.

Therefore, FIG. 9 shows the protrusion 28Ce of the front nose 28 The axial length W is preferably “0.08 ≦ W / D ≦ 0.32” from the point of balance between the stability of air supply and energy saving.

In this embodiment, as shown in FIGS. 5 to 7, the shape of the front nose portion 28 is changed in three steps. When the ventilation resistance between the indoor heat exchanger 8 and the air duct is large, the influence of the frictional resistance of the wall surface on the unstable supply air is transmitted to the axial center of the cross-flow fan 9. Therefore, it is preferable that the width WB from the side wall 32 to the center-side end portion of the front nose portion 28B is WB / D ≦ 0.72. Thereby, the air supply stability can be improved. Here, even if the curved portion connecting the front nose portion 28B and the front nose portion 28A is outside the range of WB / D ≦ 0.72, the air supply stability can be improved.

Returning to FIG. 9, the ratio W: L of the lengthwise extension L of the peripheral direction of the curved surface of the front nose portion 28 facing the cross-flow fan and the width W of the center region can be adjusted to be suitable for both ends. The changing shape of the three-dimensional flow near the center further improves the air supply stability.

When the length L in the peripheral direction is smaller than the length W in the axial direction (L / W <1), a sufficient effect of stabilizing the air supply cannot be obtained. In addition, when L / W> 5, the shape change with respect to the flow change becomes large, and there is a case where a wind-cut sound is heard from the air outlet 26.

Therefore, FIG. 9 shows the relationship between the length L (= LC-LB) and the axial length W of the protruding portion 28Ce of the nose portion 28 before. The setting is “1 ≦ L / W ≦ 5” (W ≦ L ≦ 5W ) Is better. Thereby, the wind-cut sound from the air outlet 26 is not heard, and the air supply stability can be improved.

<Effects>

The operation and effect of the air conditioner 100 according to this embodiment will be described with reference to FIGS. 12 to 15.

FIG. 12 (a) is a schematic diagram of the air conditioner 100 according to this embodiment including an air duct of an indoor unit.

An air cleaner 24 and an indoor heat exchanger 8 are disposed on the upstream side of the cross-flow fan 9 in the same shape as the axial direction of the cross-flow fan 9. Moreover, since the side wall 32 is arrange | positioned at the both ends of the cross flow fan 9, the influence of wall friction increases ventilation resistance. The air duct on the indoor fan motor 11 side (the right side in FIG. 12) has an electrical component box 33 arranged at the suction port 23 to increase the ventilation resistance.

FIG. 12 (b) is a diagram of the air velocity distribution of the air conditioner 100 according to the embodiment including the air outlet 26 of the indoor unit. In addition, the horizontal axis represents the axial position of the cross-flow fan 9, and the vertical axis represents the blowing wind speed distribution. In addition, let the vertical axis | shaft be the average blown-out wind speed when dust is not deposited on the air cleaner 24, and 100%. In addition, V0 is the air velocity distribution when the dust is not deposited on the air filter 24, V1 is the air velocity distribution when the dust is accumulated on the air filter 24 of this embodiment, and V2 is the air filtration when dust is accumulated on the conventional example The air velocity distribution of the blower at 24 o'clock.

When dust does not accumulate on the air cleaner 24, as shown in the blowing wind speed distribution V0, even if the wind speed drops slightly at both ends, no backflow occurs.

On the other hand, when dust is accumulated on the air cleaner 24, the blowing wind speed is reduced as a whole. In addition, the indoor fan motor 11 side, which was originally large in ventilation resistance, was unstable. Therefore, the conventional blowing wind speed points In cloth V2, a backflow occurs on the indoor fan motor 11 side. In contrast, in this embodiment, the flow at both ends can be stabilized and the backflow can be suppressed. Therefore, as shown by the blowing wind speed distribution V1, the wind speed can be increased.

FIG. 13 is a diagram illustrating the characteristics of the cross-flow fan 9 according to this embodiment and a conventional example. FIG. 13 shows that the cross-flow fan 9 is mounted only on the indoor unit housing 20, the indoor unit housing 21, the front nose portion 28, the front case 29, and the upper and lower sides except for the indoor heat exchanger 8 or the air cleaner 24. Characteristics of the state of the wind direction control board 27. Thereby, only the characteristics of the cross-flow fan 9 can be confirmed.

As shown in FIG. 13, in comparison with a conventional cross-flow fan shown by a dotted line, the present embodiment shown by a solid line can increase the static pressure in the same air volume. In addition, in the conventional example, before the maximum static pressure is reached, that is, the current starts to flow backward from both ends, and the fluttering sound can be heard, and as the flow at both ends is stabilized, the area where the fluttering sound is not heard can be enlarged.

Fig. 14 is a diagram comparing the fan input of the air conditioner of this embodiment and the conventional example.

The air conditioner 100 of this embodiment and the air conditioner of the conventional example which does not have the protrusion part 28Ce in the front nose part 28 are controlled so that the air volume of the air outlet 26 may become the same. At this time, when the input of the cross-flow fan 9 of the known example is 100%, the input of the cross-flow fan 9 of the air conditioner 100 of this embodiment is 100.3%. As described above, in the air conditioner 100 of this embodiment, the increase in the fan input is extremely small compared with the conventional example.

FIG. 15 shows the maximum fluctuation value of the rotation speed of the cross-flow fan 9 when the static pressure at the inlet increases in the air conditioner of this embodiment and the conventional example. Chart. In addition, this embodiment is shown by a solid line, and a conventional example is shown by a broken line.

Assuming that the rotation speed of the cross-flow fan 9 is 900 rpm, the static pressure at the inlet is increased (that is, the ventilation resistance is increased), which indicates the maximum fluctuation value of the rotation speed of the cross-flow fan 9 when the air volume is reduced. As shown in FIG. 15, in the present embodiment, even if the air flow is reduced to an unstable state, the variation of the rotation speed of the cross-flow fan 9 is smaller than that in the conventional example, and the cross-flow fan 9 can stably rotate. In other words, it can be seen that even when the air volume is reduced, it is difficult to cause backflow, and the cross-flow fan 9 can be stably rotated.

As described above, according to the air conditioner 100 of this embodiment, even in the case where the dust accumulates on the air filter or the heat exchanger, and the like, and the operation condition that the ventilation resistance of the air duct becomes large, the increase of the fan power can be suppressed while The minimum limit, and to suppress the backflow phenomenon caused by surge, can provide stable air supply.

"Modification"

The air conditioner 100 according to this embodiment is not limited to the configuration of the above embodiment, and various changes can be made without departing from the scope of the present invention.

The air conditioner 100 according to this embodiment is shown in FIG. 7, and the front nose portion 28 is directed to: the front nose portion 28A (first central portion) whose flat surface is opposite; the front nose portion 28B (second portion whose flat surface is opposite) The center portion); and the front nose portion 28C (both ends) having a curved surface and a protruding portion 28Ce have been described, but are not limited thereto. For example, the front nose portion 28A (first center portion) whose flat surface is opposite to the flat surface and the opposite surface may be curved. The front nose portion 28C (both ends) having the protruding portion 28Ce, or the front nose portion 28B (the second central portion) having a curved surface on the opposite surface and the front nose portion 28C (two surfaces) having a curved surface on the opposite surface End). That is, the shape of the central portion of the front nose portion 28 may be either the shape of the first central portion or the shape of the second central portion.

The air conditioner 100 according to the present embodiment has been described with reference to FIGS. 7 and 8, and the protruding parts 28Ce are formed as components constituting the front nose parts 28B and 28C, but the present invention is not limited thereto. For example, the front nose portion 28C may be formed on the side wall 32. Alternatively, only the protruding portion 28Ce is formed on the side wall 32, and the components constituting the front nose portion 28B are mounted on the side wall 32 to constitute the front nose portions 28B and 28C.

The air conditioner 100 according to the present embodiment has been described with reference to FIG. 8. The side 28Cf is substantially straight and the shape of the protrusion 28Ce is substantially triangular. For example, the shape of the protruding portion 28Ce may be substantially trapezoidal. In addition, although the side 28Cf has been described as being substantially straight, it is not limited to this, and it may be a curve (for example, a curve represented by a monotonic function), and the width becomes narrower toward the tip of the protrusion 28Ce.

Claims (5)

An air conditioner is connected to an indoor unit. The air conditioner includes a cross-flow fan, a plurality of fan elements are connected in a direction around the shaft, and a front nose portion is arranged along the direction around the shaft of the cross-flow fan. The opposing surface of the nose portion opposite to the cross-flow fan has a long protruding portion that gradually narrows from the side of the cross-flow fan toward the end side in the direction of the shaft along the end side of the cross-flow fan. When the diameter of the cross-flow fan is D, the widest area width W of the protruding portion in the direction around the axis of the cross-flow fan satisfies 0.08 ≦ W / D ≦ 0.32. According to the air conditioner described in claim 1, wherein the facing surface of the front nose portion is formed so that the length of the facing surface with respect to the direction of the cross-flow fan becomes closer to the end side of the cross-flow fan. For example, if the maximum length of the length of the protruding portion relative to the peripheral direction of the cross-flow fan is L, the air conditioner described in item 1 or 2 of the scope of patent application satisfies 1 ≦ L / W ≦ 5. form. The air conditioner according to item 1 or 2 of the scope of patent application, wherein the facing surface connecting the front nose portion and the connecting surface connected to the air duct surface on the side opposite to the facing surface of the front nose portion. It has a circular arc shape, and the radius of the circular arc shape is such that both end sides are shorter than the center side. According to the air conditioner described in claim 1 or claim 2, the opposing surfaces of the front nose portion on both end sides are formed to have a relationship of concentric circles with the cross flow fan.