JP2001107892A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner with a high efficiency and a low noise by enhancing a discharge pressure of turbo fan and inhibiting a peeling off of flow generated at a negative pressure surface at the time of low flow rate to enhance efficiency. SOLUTION: In respective blade cross section perpendicular to a motor rotation axis of turbo fan of an air conditioner, an outlet angle β2a on the pressure surface side, i.e., a blade surface on the rotation direction side of the blade is made larger than an outlet angle β2b on the negative pressure surface side, i.e., a blade surface on the reverse rotation direction side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an air conditioner using a turbo fan as a blower.

[0002]

2. Description of the Related Art Conventionally, turbo fans have been widely used as air blowers for air conditioners. In recent years, however, there has been a strong demand for higher performance, higher efficiency, and lower noise. Japanese Patent Application Publication No. 7-4389 discloses a method for improving performance by improving the blade shape.

FIG. 24 shows the shape of this conventional turbofan.
Shown in In this turbofan, as shown in the enlarged view of FIG. 25, the blade 23 has a cross section perpendicular to the motor rotation axis,
It has an inflection point 13 near the blade trailing edge 9, and has an airfoil from the blade leading edge to the inflection point 13 in the fan rotation direction 6. The portion up to the portion 9 has a shape substantially perpendicular to the fan rotation direction 6. Therefore, the blade exit angle β
2 increases, and the discharge pressure can be increased.

[0004]

However, the small size,
In order to increase the efficiency, the above configuration is not efficient because the air flow separation 27 occurs on the negative pressure surface 11 side of the blade trailing edge 9 particularly in a small flow rate region as shown in FIG. Had a point.

In view of the above problems, it is an object of the present invention to maintain or increase the outlet angle on the pressure surface side necessary for maintaining or increasing the discharge pressure of the turbofan, and to increase the air pressure on the negative pressure surface side. An object of the present invention is to provide a high-efficiency, low-noise air conditioner by suppressing the occurrence of flow separation, thereby improving the performance and efficiency of a turbofan in the sense of reducing motor input.

[0006]

Means for Solving the Problems To achieve the above object, an air conditioner according to the present invention is characterized by what is described in each claim of the claims. An air conditioner according to the first aspect of the present invention is an air conditioner comprising: a blower that sucks and discharges air; and a heat exchanger that is disposed on a suction side or a discharge side of the blower and that cools or heats the air. The blower is a disc-shaped boss provided with a hole for attaching a motor rotation shaft on a center axis, a hub disposed in contact with an outer peripheral edge of the boss, and the motor mounted on a surface of the hub. An impeller comprising a plurality of blades arranged in a circumferential direction around a rotation axis and a shroud arranged on the side facing the hub with the blades interposed therebetween, and a motor rotation axis fixed to the boss. A module for rotating the impeller In an air conditioner using a turbo fan composed of a turbo fan, in each blade section perpendicular to the motor rotation axis of the turbo fan, an outlet angle of a pressure surface side of a front surface in a rotation direction side of the blade is It is characterized in that it has a shape that is larger than the exit angle on the negative pressure surface side, which is the blade surface on the back surface. An air conditioner according to the invention according to claim 7 as an independent claim is a blower that sucks and discharges air, and a heat exchanger that is disposed on a suction side or a discharge side of the blower and cools or heats the air. An air conditioner comprising: a blower, a disc-shaped boss provided with a hole for mounting a motor rotation shaft on a central axis,
A hub arranged in contact with the outer peripheral edge of the boss, a plurality of blades arranged on a surface of the hub in a circumferential direction around the motor rotation axis, and a side opposed to the hub with the blades interposed therebetween An air conditioner using a turbo fan composed of an impeller made of a shroud disposed on the boss and a motor rotating the impeller with a motor rotating shaft fixed to the boss, wherein the motor of the turbo fan is used. The cross-sectional shape of each blade perpendicular to the rotation axis is characterized in that the outlet angle on the pressure surface side of the blade is continuously increased from the hub side to the shroud side, and the suction surface is shaped like an airfoil. Things.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a turbofan used in an air conditioner according to the present invention will be described below with reference to FIGS.

FIG. 1 is a partially cutaway plan view of a turbofan of an air conditioner according to a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view. This turbofan has a disk-shaped boss 2 provided with a hole for mounting a motor rotation shaft on a center axis,
A hub 3 arranged in contact with the outer peripheral edge of the hub 3, a plurality of blades 4 arranged on a surface of the hub 3 in a circumferential direction around the motor rotation axis, and the hub 3 sandwiching the blades 4 therebetween. 1 and a motor 7 that fixes the motor rotation shaft 8 to the boss 2 and rotates the impeller, and is indicated by an arrow in FIG. 1. It is rotationally driven by the motor 7 in the rotational direction 6.

FIG. 3 is an enlarged view of the trailing edge portion 9 of the blade. The intersection between the pressure surface 10 of the blade 4 and the outer periphery 1 of the turbofan (hereinafter referred to as “the trailing edge on the pressure surface 10 side”) is shown in FIG.
An angle (hereinafter referred to as “pressure”) between the straight line 24a connecting the center of the motor rotation shaft 8 and the straight line 25a at the rear edge of the pressure surface 10 and the pressure surface 10 at the rear edge of the pressure surface 10 The exit angle on the surface 10 side) is β2
a, Suction surface 11 of blade 4 and outer periphery 1 of turbo fan
(Hereinafter referred to as “the trailing edge on the suction surface 11 side”), a straight line 24b connecting the center of the motor rotation shaft 8 to a straight line 25b orthogonal to the trailing edge on the suction surface 11 side, and the suction surface 11 (hereinafter referred to as “the exit angle on the suction surface 11 side”) is β2b. At this time, in a cross section of the blade 4 cut by a plane perpendicular to the motor rotation axis 8, as shown in FIG. 3, the outlet angle β2a on the pressure surface 10 side is larger than the outlet angle β2b on the negative pressure surface 11 side. The blade 4 was formed.

In the present embodiment, the outlet angle β on the suction surface 11 side
By making 2b smaller than the outlet angle β2a on the pressure surface 10 side, separation 27 of the air flow on the negative pressure surface 11 side is less likely to occur, and the efficiency can be improved. On the other hand, the outlet angle β2a on the pressure surface 10 side is the outlet angle β of the suction surface 11.
2b, the discharge pressure at the fan outlet can be increased.

FIG. 4 is a longitudinal sectional view of an indoor unit of an air conditioner equipped with the turbo fan 29 shown in FIG. The illustrated indoor unit includes a box-shaped cabinet 28 having an open surface, and a turbo fan 2 fixed to an opening of the cabinet 28.
9 and a heat exchanger 30 arranged around the outlet of the turbofan 29. A bell mouth 31 is disposed at an inlet of the impeller, and the bell mouth 3
A suction grille 33 provided with a filter 32 is mounted below 1. Further, a panel 34 having an air outlet 35 is disposed downstream of the heat exchanger 30.

In the indoor unit having the above-described structure, air passes through the suction grille 33 and the filter 32 from the room and passes through the bellmouth 3.
While being rectified by 1, it is sucked into the turbo fan 29. The air discharged from the turbo fan 29 is cooled or heated by the heat exchanger 30 and blown into the room through the air outlet 35 of the panel 34.

FIG. 5 shows a blower outlet of FIG.
3A is an enlarged cross-sectional view taken along line BB of portion A of FIG. As shown in FIG. 5, the outlet angle β2a on the pressure surface 10 side is larger than the outlet angle β2b on the negative pressure surface 11 side.

In the indoor unit of the air conditioner of the present invention, the efficiency of the turbofan 29 is high, so that the power consumption can be suppressed low. In addition, since the discharge pressure is large, the number of revolutions of the fan for producing the same air volume can be suppressed. .

The present embodiment shows an example in which the turbo fan 29 is applied to an indoor unit of an air conditioner installed on the indoor ceiling, but can also be applied to an outdoor unit. Further, in this example, the heat exchanger 30 is provided on the discharge side, but the heat exchanger 30 may be provided on the suction side.

FIG. 6 is a partially broken plan view of a turbofan 29 of an air conditioner according to a second embodiment of the present invention.
FIG. 7 is an enlarged view of the blade trailing edge 9. The difference from the first embodiment is that the shape of the pressure surface 10 has an inflection point 13 near the trailing edge 9 of the blade on a cross section perpendicular to the motor rotation axis 8, and the inflection point 13 13, the shape of the pressure surface 10 forms an airfoil in the fan rotation direction 6, and from the inflection point 13 to the blade trailing edge 9, a concave or vertical curve is formed in the fan rotation direction 6. That is, it is configured so that On the other hand, the suction surface 11
The shape of the side is airfoil toward the fan rotation direction 6 over the entire length of the blade 12. In the second embodiment, the loss due to the separation 27 of the air flow on the suction surface side can be suppressed in the same manner as in the first embodiment, and the outlet angle β2a on the pressure surface 10 side can be increased to almost vertical. As a result, a turbo fan having a higher discharge pressure at the fan outlet can be obtained as compared with the first embodiment, so that the fan speed of the air conditioner can be further reduced, and the blowing noise can be reduced.

In this embodiment, the shape of the pressure surface 10 extends from the blade leading edge to the inflection point 13 in the fan rotation direction 6.
Although an example in which an airfoil is formed is shown in FIG.

FIG. 8 is a partially broken plan view of a turbofan 29 of an air conditioner according to a third embodiment of the present invention.
FIG. 9 is an enlarged view of the blade trailing edge 9. The difference from the second embodiment is that the blade trailing edge portion 9 is branched into two, a pressure surface side blade trailing edge 15 and a suction surface side blade trailing edge 16. Since the shapes of the pressure surface 10 and the suction surface 11 are the same as those of the second embodiment, the blowing performance of the turbo fan 29 is the same as that of the second embodiment, but the wall pressure at the blade trailing edge 9 is reduced. This has the advantage that the material can be reduced.

Comparing the turbo fan 29 shown in FIG. 8 with the conventional turbo fan 29 shown in FIG. 24, the discharge pressure is almost the same, and the efficiency is 3 to 5% in the use range of the air conditioner.
To a degree. When this turbofan is installed in the indoor unit of the air conditioner shown in FIG. 4, the power consumption of the indoor unit is 3 to 5
%.

FIG. 10 is a partially cutaway plan view of a turbofan 29 of an air conditioner according to a fourth embodiment of the present invention, and FIG. 11 is an enlarged view of a trailing edge portion 9 of the blade. This embodiment differs from the third embodiment in that a through hole 19 is provided at the trailing edge 15 of the pressure surface side blade from the pressure surface 10 side toward the intermediate portion 17. The first to third
In the embodiment, since the distance between the pressure surface 10 and the suction surface 11 is large at the blade trailing edge 9, for example, in the third embodiment, as shown in FIG. Due to the pressure difference between the trailing edge 16 and the intermediate portion 17, a vortex 26 is generated from the leading end of the trailing edge 15 of the pressure-side blade and the trailing edge 16 of the suction-side blade, which may cause turbulent noise. On the other hand, in the fourth embodiment, the through hole 1
When air flows from the pressure-surface-side blade trailing edge 15 to the intermediate portion 17 through 9, the pressure in the intermediate portion 17 can be increased. Therefore, the trailing edge 15 of the pressure side blade and the trailing edge 16 of the negative pressure side blade and the intermediate portion 17
13, the generation of large vortices at the trailing edge 15 of the pressure side blade and the trailing edge 16 of the suction side blade can be suppressed as shown in FIG. Flow noise can be reduced, and an air conditioner with high efficiency and low noise can be provided.

FIG. 14 is a partially cutaway plan view of a turbofan 29 of an air conditioner according to a fifth embodiment of the present invention.
5 is a longitudinal sectional view, and FIGS. 16 to 18 are enlarged views of the blade trailing edge 9 in AA section, BB section, and CC section perpendicular to the motor rotation shaft 8 in FIG. 15, respectively. It is.
This embodiment differs from the first to fourth embodiments in that the outlet angle β2a on the pressure surface side of the blade trailing edge 9 has a different blade shape depending on the height. That is, on the CC section shown in FIG. 18, the outlet angle β2a on the pressure surface 10 side is a conventional shape smaller than the outlet angle β2b on the negative pressure surface 11 side, but goes from the hub 3 side to the shroud 5 side. As a result, the cross-sectional shape changes continuously, and the outlet angle β2a on the pressure surface side 10 gradually increases.
Therefore, in the fifth embodiment, the effect of increasing the discharge pressure increases from the hub 3 side to the shroud 5 side, and as a result, the pressure distribution in the height direction at the fan outlet 21 can be improved, and the shroud 5 side The separation 27 of the air flow in the air is suppressed, and the velocity distribution of the blown air between the hub 3 and the shroud 5 is made uniform. That is, the efficiency and the discharge pressure can be improved, and the maximum speed at the outlet can be suppressed small, so that the fluid noise can be reduced.

FIG. 19 is a partially cutaway plan view of a turbofan 29 of an air conditioner according to a sixth embodiment of the present invention.
0 is a longitudinal sectional view, and FIGS. 21 to 23 are AA cross sections and BB perpendicular to the motor rotation shaft 8 in FIG. 20, respectively.
It is an enlarged view of the blade trailing edge part 9 in a cross section and a CC cross section. As in the fifth embodiment, the shape changes from the hub 3 side to the shroud 5 side, but the outlet angle β2a on the pressure surface side between the hub 3 and the shroud 5 is constant, and the blade pressure surface Inflection point 13 from hub side 3 to shroud 6
It is shaped so as to move away from the blade trailing edge 9 toward the side. That is, the closer to the shroud 5, the higher the effect of increasing the discharge pressure, and the same effect as in the fifth embodiment can be expected.

[0023]

The air conditioner according to the present invention includes a turbofan that sucks and discharges air, and a heat exchanger that is disposed on the suction side or the discharge side of the turbofan and that cools or heats the air. In the turbo fan, in each blade section perpendicular to the motor rotation axis, the outlet angle of the blade on the pressure surface side is larger than the outlet angle on the suction surface side. Therefore, the discharge pressure can be increased by increasing the outlet angle on the pressure surface side, and the separation of the air flow on the negative pressure surface side can be suppressed, so that the efficiency can be increased.

Further, the number of rotations for obtaining the same pressure can be kept low. Therefore, an air conditioner with low blowing sound and high efficiency can be obtained. When the air conditioner is mounted on an indoor unit, the power consumption of the indoor unit of the air conditioner is reduced by 3
About 5%.

[Brief description of the drawings]

FIG. 1 is a partially broken plan view of a turbo fan according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the turbo fan according to the first embodiment of the present invention.

FIG. 3 is an enlarged view of a trailing edge of a blade of the turbofan according to the first embodiment of the present invention.

FIG. 4 is a sectional view of an indoor unit of an air conditioner to which a turbofan according to an embodiment of the present invention is attached.

FIG. 5 is an enlarged view of a trailing edge portion of the blade in a BB cross section of a portion A in FIG. 4;

FIG. 6 is a partially cutaway plan view of a turbofan according to a second embodiment of the present invention.

FIG. 7 is an enlarged view of a trailing edge of a blade of a turbofan according to a second embodiment of the present invention.

FIG. 8 is a partially broken plan view of a turbofan according to a third embodiment of the present invention.

FIG. 9 is an enlarged view of a trailing edge of a blade of a turbofan according to a third embodiment of the present invention.

FIG. 10 is a partially broken plan view of a turbofan according to a fourth embodiment of the present invention.

FIG. 11 is an enlarged view of a trailing edge of a blade of a turbofan according to a fourth embodiment of the present invention.

FIG. 12 is a schematic diagram illustrating a flow at a trailing edge of a blade of a turbofan according to a third embodiment of the present invention.

FIG. 13 is a schematic diagram showing a flow at a trailing edge of a blade of a turbofan according to a fourth embodiment of the present invention.

FIG. 14 is a partially broken plan view of a turbofan according to a fifth embodiment of the present invention.

FIG. 15 is a longitudinal sectional view of a turbo fan according to a fifth embodiment of the present invention.

16 is an enlarged view of a trailing edge portion of the blade in the AA cross section in FIG. 15;

FIG. 17 is an enlarged view of a trailing edge portion of the blade in a BB section in FIG. 15;

18 is an enlarged view of a trailing edge portion of the blade in a cross section taken along line CC in FIG.

FIG. 19 is a partially broken plan view of a turbofan according to a sixth embodiment of the present invention.

FIG. 20 is a vertical sectional view of a turbofan according to a sixth embodiment of the present invention.

FIG. 21 is an enlarged view of a trailing edge portion of the blade in an AA section in FIG. 20;

FIG. 22 is an enlarged view of a trailing edge portion of the blade in a BB section in FIG. 20;

FIG. 23 is an enlarged view of a trailing edge portion of the blade in a section taken along line CC in FIG. 20;

FIG. 24 is a partially broken plan view of an example of a conventional turbofan.

FIG. 25 is an enlarged view of a trailing edge of a blade in an example of a conventional turbofan.

FIG. 26 is a schematic view showing a flow at a trailing edge of a blade in an example of a conventional turbofan.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Turbo fan outer periphery 2 ... Boss 3 ... Hub 4 ... Blade 5 ... Shroud 6 ... Rotation direction 7 ... Motor 8 ... Motor rotation shaft 9 ... Blade trailing edge 10 ... Pressure surface 11 ... Negative pressure surface 12 ... Blade 13 ... Inflection Point 14: Blade 15: Trailing edge of pressure side blade 16: Trailing edge of suction side 17: Intermediate portion 18: Blade 19: Through hole 20: Blade 21: Fan outlet 22: Blade 23: Blade 24a: Straight line 24b Straight line 25a Straight line 25b Straight line 26 Vortex 27 Separation of air flow 28 Cabinet 29 Turbo fan 30 Heat exchanger 31 Bell mouth 32 Filter 33 Suction grill 34 Panel 35 Air outlet β2a Pressure surface side outlet angle β2b ... Negative pressure surface side outlet angle

Continued on the front page (72) Inventor Ryoji Sato 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Inside Hitachi Air Conditioning Systems Shimizu Production Headquarters (72) Inventor Hiroyasu Yoneyama 390 Muramatsu, Shimizu-shi Shizuoka Prefecture Hitachi Shimizu Engineering Co., Ltd. (72) Inventor Tetsushi Kishitani 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture F-term in Hitachi Air Conditioning Systems Shimizu Production Headquarters (reference) 3H033 AA02 AA18 BB02 CC02 DD03 EE19

Claims (9)

[Claims] 1. An air conditioner comprising: a blower for sucking and discharging air; and a heat exchanger disposed on a suction side or a discharge side of the blower for cooling or heating air. A disk-shaped boss provided with a hole for mounting a motor rotating shaft on a center axis, a hub arranged in contact with an outer peripheral edge of the boss, and a circumferential direction centered on the surface of the hub around the motor rotating shaft. A plurality of blades disposed in the impeller and a shroud disposed on the side facing the hub sandwiching the blades, and a motor that rotates the impeller by fixing a motor rotation shaft to the boss In an air conditioner using a turbo fan composed of: In each blade cross section perpendicular to the motor rotation axis of the turbo fan, the outlet angle of the pressure surface side of the front surface in the rotation direction side of the blade is the back surface. On the wing surface An air conditioner characterized in that it forms a shape larger than the exit angle of the negative pressure surface side that. 2. The air conditioner according to claim 1, wherein the shape of the pressure surface side in each of the blade cross sections perpendicular to the motor rotation axis of the turbo fan is an airfoil. 3. The cross section of each of the blades perpendicular to the motor rotation axis of the turbofan, wherein the shape on the pressure surface side has an inflection point at an arbitrary radius around the motor rotation axis, The air conditioner according to claim 1, wherein the shape of the pressure surface forms a concave curve or a vertical straight line toward the fan rotation direction from the inflection point to the blade trailing edge. 4. The cross section of each of the blades perpendicular to the motor rotation axis of the turbo fan, wherein the shape of the pressure surface has an inflection point at an arbitrary radius centered on the motor rotation axis; The shape of the surface forms an airfoil in the direction of fan rotation from the leading edge of the blade to the inflection point, and forms a concave curve or a vertical straight line from the inflection point to the blade trailing edge. 2. The air conditioner according to 1. 5. The blade of the turbofan according to claim 1, wherein the trailing edge of the blade is reduced in thickness, and the trailing edge of the blade is divided into two and branched into a pressure surface side and a suction surface side. Item 5. The air conditioner according to any one of Items 1 to 4. 6. A through-hole is provided between an intermediate portion between a trailing edge of a blade on the pressure surface side and a trailing edge of a blade on the suction surface side and a trailing edge of the blade on the pressure surface side. The air conditioner according to claim 5, characterized in that: 7. An air conditioner comprising: a blower for sucking and discharging air; and a heat exchanger disposed on a suction side or a discharge side of the blower for cooling or heating air. A disk-shaped boss provided with a hole for mounting a motor rotating shaft on a center axis, a hub arranged in contact with an outer peripheral edge of the boss, and a circumferential direction centered on the surface of the hub around the motor rotating shaft. A plurality of blades disposed in the impeller and a shroud disposed on the side facing the hub sandwiching the blades, and a motor that rotates the impeller by fixing a motor rotation shaft to the boss In the air conditioner using a turbo fan composed of: The cross-sectional shape of each blade perpendicular to the rotation axis of the motor of the turbo fan is such that the outlet angle on the pressure surface side of the blade is directed from the hub side to the shroud side. Or Continuously made large As the negative pressure surface is an air conditioner which is characterized in that a shape is an airfoil. 8. A cross section of each blade perpendicular to the motor rotation axis of the turbo fan, wherein an outlet angle on the pressure surface side of the blade is smaller than an outlet angle on the suction surface side on the hub surface,
The outlet angle on the pressure side of the blade is continuously increased from the hub side to the shroud side, and the outlet angle on the pressure side is larger than the outlet angle on the suction side on the shroud side. Item 7. The air conditioner according to Item 7. 9. An air conditioner comprising: a blower for sucking and discharging air; and a heat exchanger disposed on a suction side or a discharge side of the blower for cooling or heating air. A disk-shaped boss provided with a hole for mounting a motor rotating shaft on a center axis, a hub arranged in contact with an outer peripheral edge of the boss, and a circumferential direction centered on the surface of the hub around the motor rotating shaft. A plurality of blades disposed in the impeller and a shroud disposed on the side facing the hub sandwiching the blades, and a motor that rotates the impeller by fixing a motor rotation shaft to the boss In an air conditioner using a turbo fan composed of: A cross section of each blade perpendicular to the motor rotation axis of the turbo fan has a pressure surface at a position of an arbitrary radius around the motor rotation axis. Inflection point The blade has an airfoil from the blade leading edge to the inflection point in the direction of rotation of the fan, forms a concave curve or a vertical straight line from the inflection point to the blade trailing edge, and an exit angle on the pressure surface side. Wherein the distance between the inflection point and the trailing edge of the blade is increased from the hub surface toward the shroud surface, and the suction surface is an airfoil.