US20150219348A1

US20150219348A1 - Air conditioning apparatus

Info

Publication number: US20150219348A1
Application number: US14/429,491
Authority: US
Inventors: Takashi Ikeda; Kazuhiko Kawai; Yuki Mochizuki; Ippei Shinoda; Yuichi Yata
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2013-09-09
Filing date: 2013-09-09
Publication date: 2015-08-06
Also published as: EP3045827A1; JPWO2015033467A1; EP3045827A4; WO2015033467A1; CN104755848A; CN104755848B; EP3045827B1; JP5823064B2

Abstract

Provided is an air conditioning apparatus, including a unit main body in which a heat exchanger and at least one blower fan are provided. The heat exchanger is arranged on an upstream side of the blower fan. The blower fan includes an impeller, a motor, and a fan casing. The impeller is a turbofan that sucks air from an upper portion thereof and blows out the air radially outward. A rotation axis of the impeller is directed to a unit height direction. The fan casing has a fan air inlet formed in an upper surface thereof, and has a fan air outlet formed in a lower surface thereof. An impeller air outlet of the impeller is covered by side surfaces of the fan casing.

Description

TECHNICAL FIELD

The present invention relates to an air conditioning apparatus.

BACKGROUND ART

Patent Literature 1 and Patent Literature 2 disclose air conditioning apparatus of a downward-blowing type, which are used for air-conditioning a computer room and the like. Patent Literature 1 and Patent Literature 2 disclose the air conditioning apparatus each having such a configuration that a V-shaped or inverted V-shaped heat exchanger is arranged on an upstream side of a blower fan. The blower fan includes a plurality of impellers, a plurality of volute fan casings arranged around the corresponding impellers, and a motor for driving the impellers. Each of the impellers is arranged so that a rotation axis thereof is directed to a horizontal direction. Further, air inlets of the blower fan are directed sideways, and air outlets of the blower fan are directed downward. The plurality of impellers are driven by one motor.
In each of the air conditioning apparatus, the air is sucked from a unit air inlet formed in an upper surface of a unit, and the air that is conditioned into a desired state is blown out from a unit air outlet formed in a lower surface of the unit, toward an underfloor space in which the air conditioning apparatus is placed. The air passes through the underfloor space and gradually flows out upward from a surface of a floor, and thus a computer and a room are subjected to an air-conditioning effect.
Further, Patent Literature 3 discloses an air conditioning apparatus in which two heat exchangers are arranged in an inverted V-shape so that lower portions of the heat exchangers are spaced apart from each other. Side block plates are arranged on both side surfaces of the two heat exchangers, and an upper block plate is arranged on upper portions of the two heat exchangers. Drain pans for collecting dew condensation water are arranged below the heat exchangers, respectively. A blower fan, which is arranged inside a unit, sucks the air from a unit air inlet formed in a lower portion of the unit. After the blower fan causes the sucked air to pass through the heat exchangers arranged in an inverted V-shape as described above, and then subjects the sucked air to desired heat exchange, the blower fan blows out the air from a unit air outlet formed in an upper portion of the unit, and blows out the air toward an air outlet duct provided to the unit air outlet. Further, the blower fan is configured so that a fan air inlet thereof is directed to a side surface of the unit and a fan air outlet thereof is directed to an upper surface of the unit.

CITATION LIST

Patent Literature

[PTL 1] JP 6-12465 Y2 (pp. 1 and 2, FIG. 2)
[PTL 2] JP 2011-202821 A (pp. 5 to 7, FIG. 2)
[PTL 3] JP 9-273801 A (pp. 2 and 3, FIGS. 1)

SUMMARY OF INVENTION

Technical Problems

However, the above-mentioned related-art air conditioning apparatus have the following problems.
First, in the air conditioning apparatus disclosed in Patent Literatures 1 and 2, there is a problem in that, when an airflow blown out from the impellers collides with the underfloor space, airflow resistance is high particularly in a place where a height of the underfloor space is low, and hence power consumption of the motor is increased. Further, the blown-out airflow may stir up dust underneath the floor.
Further, in the air conditioning apparatus disclosed in Patent Literature 3, there is a problem in that, when an airflow blown out from the impeller flows into and collides with the air outlet duct provided to the unit air outlet, airflow resistance is high, and hence power consumption of a motor is increased.
The present invention has been made in view of the above-mentioned problems, and has an object to provide an air conditioning apparatus capable of reducing power consumption of a motor along with reduction in airflow resistance.

Solution to Problems

In order to achieve the above-mentioned object, according to one embodiment of the present invention, there is provided an air conditioning apparatus, including: a unit main body; a heat exchanger; and at least one blower fan. The heat exchanger is arranged on an upstream side of the blower fan. The blower fan includes an impeller, a motor, and a fan casing. The impeller is a turbofan that sucks air from an upper portion thereof and blows out the air radially outward. A rotation axis of the impeller is directed to a unit height direction. The fan casing has a fan air inlet formed in an upper surface thereof, and has a fan air outlet formed in a lower surface thereof. An impeller air outlet of the impeller is covered by side surfaces of the fan casing.
The blower fan may be arranged below the heat exchanger.
The impeller may include a plurality of blades, a side plate having a ring shape, and a main plate, the side plate may be positioned on the fan air inlet side, the main plate may be positioned on the fan air outlet side, and an outer diameter φDs of the side plate may be larger than an outer diameter φDm of the main plate.
An outer diameter φDb1 of each of the blades on the side plate side may be larger than an outer diameter φDb2 of each of the blades on the main plate side.
The blower fan may include a plurality of blower fans.
The plurality of blower fans may be arranged with an interval in a widthwise direction.
The plurality of blower fans may be controlled so as to have mutually different numbers of revolutions of the fans.
The fan casing may include a frame body, and at least one side wall surface removably mounted to the frame body.
The blower fan may include a motor support for supporting the motor, and the motor support may be positioned closer to a side on which the fan air outlet is formed than the main plate of the impeller.
The side surfaces of the fan casing may include at least one flat surface.
The fan casing may include at least one chamfered portion that, with reference to a rectangular shape of the fan casing in plane view, at a portion corresponding to a corner of the rectangular shape.
The heat exchanger may have a shape including at least one bent portion.
The heat exchanger may have an inverted V-shape or an M-shape.

Advantageous Effects of Invention

According to the one embodiment of the present invention, reduction in power consumption of the motor along with reduction in airflow resistance can be achieved.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an external perspective view illustrating an air conditioning apparatus according to a first embodiment of the present invention.

FIG. 2 is a side longitudinal cross-sectional view illustrating the air conditioning apparatus of FIG. 1.

FIG. 3 is a front longitudinal cross-sectional view illustrating the air conditioning apparatus of FIG. 1.

FIG. 4 is a perspective view illustrating a blower fan of the air conditioning apparatus of FIG. 1.

FIG. 5 is a cross-sectional view taken along the line V-V of FIG. 2.

FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. 5.

FIG. 7 is a view schematically illustrating an airflow formed inside the blower fan of FIG. 4.

FIG. 8 is a view illustrating a second embodiment of the present invention and corresponding to FIG. 5.

FIG. 9 is a view illustrating a third embodiment of the present invention and corresponding to FIG. 2.

FIG. 10 is a view illustrating a modified example of the third embodiment and corresponding to FIG. 3.

FIG. 11 is a view illustrating the modified example of the third embodiment and corresponding to FIG. 2.

DESCRIPTION OF EMBODIMENTS

Now, an air conditioning apparatus according to embodiments of the present invention is described with reference to the accompanying drawings. Note that, in the drawings, the same reference symbols represent the same or corresponding parts. The air conditioning apparatus according to the embodiments of the present invention can be used for, as an example, a computer room in which air cleaning, dehumidifying, and air-cooling are performed.

First Embodiment

FIG. 1 is an external perspective view illustrating an air conditioning apparatus according to a first embodiment of the present invention. FIG. 2 is a side longitudinal cross-sectional view illustrating the air conditioning apparatus of FIG. 1, and FIG. 3 is a front longitudinal cross-sectional view illustrating the air conditioning apparatus of FIG. 1.
In FIGS. 1 to 3, a contour of a unit main body 100 is formed in such a manner that a main body top plate 100 a having a unit air inlet 101 formed in an upper surface of the main body, main body side plates 100 b, and a main body bottom plate 100 c having a unit air outlet 102 formed in a lower surface of the main body are mounted to a main body frame 100 d. Each of the main body side plates 100 b is divided so as to have a configuration capable of being dismounted separately for maintenance of an inside of the main body.
Further, the unit main body 100 is arranged between a ceiling 121 and a floor 118 of a room 117, that is, placed on the floor 118. In many cases, the unit main body 100 is arranged along a wall 120. The floor 118 has double flooring structure. An opening hole 118 a is formed in the floor 118 so as to be communicated to an underfloor space 119.
Inside the unit main body 100, an air cleaning filter 103 is removably mounted to the unit air inlet 101.
The floor 118, on which the unit main body 100 is placed, has a plurality of opening portions formed in portions thereof on a downstream side of a flow of the air-conditioned air. The air-conditioned air is supplied, through the opening portions, to a computer storage rack and an air conditioning apparatus that is separately placed, and thus computers are cooled. That is, in the entire room, there is formed a circulating flow including an airflow flowing upward from below around an object to be cooled.
On a downstream side of the unit air inlet 101, a heat exchanger 104, a drain pan 114 for collecting condensed water, and two blower fans 107 are arranged. The drain pan 114 for collecting condensed water is arranged below the heat exchanger 104, and the blower fans 107 are arranged below the drain pan 114.
The heat exchanger 104 includes two heat exchanger forming sections 104 a each having a flat-plate-like shape, and is supported by a bracket 104 b. The heat exchanger forming sections 104 a are arranged in a V-shape so that an interval between end port ions of the heat exchanger forming sections 104 a on a unit upper side is larger than an interval between end portions of the heat exchanger forming sections 104 a on a unit lower side. A coupling plate 105 is mounted between the end portions of the pair of heat exchanger forming sections 104 a on the unit upper side, and fixing plates 106 are mounted to the pair of heat exchanger forming sections 104 a on both sides of the unit (on both front and back sides of the drawing sheet of FIG. 2). With this, the air sucked into the unit is accelerated to reach the blower fans 107 after flowing through the heat exchanger forming sections 104 a.
The heat exchanger 104 is connected, through a refrigerant pipe, to an outdoor unit (not shown) including a compressor arranged therein. Further, on a downstream side portion of each of the heat exchanger forming sections 104 a, a plurality of sub-drain pans 113 are arranged. With this, even if dew condensation water drips down from the heat exchanger 104, drops of water are collected in the sub-drain pans 113, and can be discharged into the drain pan 114.
As illustrated in FIG. 3, the blower fans 107 each include an impeller 108, a motor 109, a fan casing 110, and a motor support 111. The two blower fans 107 are arranged with an interval in a widthwise direction. More specifically, the two blower fans 107 are arranged so that adjacent fan casings 110 described later are separated from each other. Further, as an example, the two blower fans are controlled so as to have mutually different numbers of revolutions of the fans. Note that, in a specific example of the first embodiment, the two blower fans are provided, but this embodiment and the present invention are not limited thereto. Three or more blower fans may be provided.
Next, details of the blower fans are described. FIG. 4 is a perspective view illustrating one of the blower fans of the air conditioning apparatus of FIG. 1. FIG. 5 is a cross-sectional view taken along the line V-V of FIG. 2. FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. 5. FIG. 7 is a view schematically illustrating an airflow formed inside the blower fan of FIG. 4.
The impeller 108 is a turbofan that sucks the air from an upper portion thereof and blows out the air radially outward. Specifically, the impeller 108 includes a plurality of blades 108 a, a side plate 108 b having a ring shape, and a main plate 108 c. As illustrated in FIG. 2, the impeller 108 is arranged so that a rotation axis thereof is directed to a height direction H (an up-and-down direction, or a vertical direction) of the unit. The impeller 108 is arranged so that the side plate 108 b, the plurality of blades 108 a, and the main plate 108 c are provided in the stated order from the unit upper side.
Each of the plurality of blades 108 a is formed so that not a radially inner portion but a radially outer portion thereof is positioned at the rear in a fan rotation direction RO. The plurality of blades 108 a extend in the height direction between the side plate 108 b and the main plate 108 c.
The side plate 108 b is positioned on an upstream side of the plurality of blades 108 a, that is, on a fan air inlet 107 a side in the impeller 108. The side plate 108 b has a ring shape having an opening formed in a center thereof in plan view, and functions as a wall through which the air is sucked and guided. On the other hand, the main plate 108 c is positioned on a fan air outlet 107 b side in the impeller 108, and is connected to and astride lower ends of the plurality of blades 108 a. A rotation shaft 109 a of the motor 109 for rotationally driving the impeller 108 is fixed to the main plate 108 c.
An outer diameter φDs of the side plate 108 b of the impeller 108 is larger than an outer diameter φDm of the main plate 108 c of the impeller 108. Further, regarding an outer diameter of each of the blades 108 a, an outer diameter φDb1 on the side plate side in an extending direction of the rotation shaft 109 a is larger than an outer diameter φDb2 on the main plate side.
The fan casing 110 includes a frame body 110 a formed into a substantially rectangular parallelepiped shape, a bell-mouth 112 mounted to the frame body 110 a, and four side wall surfaces 110 b. The bell-mouth 112 is mounted to an upper portion of the frame body 110 a, and has the fan air inlet 107 a formed therein so as to be communicated to an impeller air inlet 108 d. The four side wall surfaces 110 b are removably mounted to corresponding side portions of the frame body 110 a, respectively.
With this, it can be considered that an upper surface of the fan casing 110 having a substantially rectangular parallelepiped shape is formed by the bell-mouth 112, and that four side surfaces of the fan casing 110 are formed by the four side wall surfaces 110 b. A further radially outer side of an impeller air outlet 108 e of the impeller 108 is covered by side surfaces of the fan casing 110, and the side surfaces of the fan casing 110 can be opened and closed through mounting and dismounting of the side wall surfaces 110 b.
Further, an opening is formed in a region corresponding to a bottom surface of the fan casing 110, which also serves as a surface opposed to the bell-mouth 112. The opening functions as the fan air outlet 107 b. As illustrated in FIG. 2, the fan air outlet 107 b is formed so as to be communicated to the unit air outlet 102. That is, the fan casing 110 has the fan air inlet 107 a formed in an upper surface thereof, and has the fan air outlet 107 b formed in a lower surface thereof.
Note that, the motor support 111 is positioned on the fan air outlet 107 b side of the main plate 108 c of the impeller.
In the air conditioning apparatus configured as described above, when the impeller 108 is rotationally driven by the motor 109 about a rotation center O, the air in the room 117 is sucked into the air conditioning apparatus through the unit air inlet 101. The air, from which dust is removed by the air cleaning filter 103, is cooled and dehumidified by the heat exchanger 104, guided to the bell-mouth 112 serving as the fan air inlet 107 a of the blower fan 107, and sucked toward the impeller 108 from above. As illustrated in FIG. 7, the sucked air is subjected to actions of the plurality of blades 108 a, and thus is blown out from sides of the impeller 108, that is, from the impeller air outlet 108 e. In addition, the sucked air is deflected downward by the side wall surfaces 110 b of the fan casing 110. That is, the air sucked toward the impeller 108 is once blown out toward the sides different from the fan air outlet 107 b, and is deflected to the fan air outlet 107 b under the actions of the side wall surfaces 110 b of the fan casing 110. Then, the sucked air flows through the unit air outlet 102 into the underfloor space 119.
According to the air conditioning apparatus of the first embodiment configured as described above, the following excellence can be obtained. First, in the air conditioning apparatus according to the first embodiment, the air sucked toward the impeller is once blown out toward the sides different from the fan air outlet, and is deflected to the fan air outlet under the actions of the side wall surfaces of the fan casing, to thereby be sent from the unit air outlet. Accordingly, as compared to a case where the air is directly blown out from the impeller toward the unit air outlet, velocity of the air flowing out from the unit air outlet is satisfactorily reduced in the first embodiment. Accordingly, velocity of the air flowing into the underfloor space is low, and hence the air is prevented from colliding with a bottom surface of the underfloor space while keeping a high-velocity flow. Thus, airflow resistance can be reduced, and particularly in a property that does not allow a long distance to the bottom surface of the underfloor space and has a small-height underfloor space, an effect of reducing airflow resistance can be significantly obtained, which is effective. Accordingly, finally, power consumption of the motor can be reduced, and energy saving can be achieved. Further, the blown-out air flows at low velocity, and hence it is possible to reduce a problem in that the blown-out air stirs up dust underneath the floor. That is, it is possible to obtain an energy-saving, silent, and high-quality air conditioning apparatus.
In addition, according to the first embodiment, in a mode in which each of the blower fans is arranged below the heat exchanger, the fan air inlet is formed in the upper surface of the fan casing. Accordingly, unlike a case where the fan air inlet is formed in a side surface of the fan casing, it is possible to prevent local concentration of the airflow. Therefore, when the air is sucked from the heat exchanger arranged above the fan air inlet, wind velocity is equalized over the fan air inlet, and is not increased locally. Accordingly, reduction in noise level can be achieved.
Further, the outer diameter φDs of the side plate of the impeller is larger than the outer diameter φDm of the main plate of the impeller. Thus, when the airflow from the impeller air outlet is deflected by the side wall surfaces of the fan casing, an airflow path is enlarged on the main plate side of the impeller, and hence the airflow is easily deflected. With this, airflow resistance can be further reduced, and power consumption of the motor can be further reduced.
Further, the outer diameter φDb1 of each of the blades on the side plate side is larger than the outer diameter φDb2 of each of the blades on the main plate side, and hence an air blowing amount in a side-plate-side region of each blade can be increased as compared to an air blowing amount in a main-plate-side region of each blade. Thus, the airflow is easily deflected toward the fan air outlet. As a result, it is possible to reduce power consumption of the motor, and it is possible to reduce noise caused when the airflow collides with wall surfaces when deflected. That is, also with this, it is possible to obtain an air conditioning apparatus capable of saving energy and reducing noise level.
Further, the plurality of blower fans are provided, and hence the air can be sucked in a large range. Even when the heat exchanger has an elongate body, a wind velocity distribution in the heat exchanger can be equalized. Accordingly, the heat exchanger can be employed effectively, and it is not necessary to increase an air blowing amount uselessly. Also with this, power consumption of the motor can be reduced, and reduction in noise level can be achieved.
Further, the plurality of blower fans are arranged with an interval in the widthwise direction, and hence it is possible to prevent the adjacent fans from scrambling for the airflow toward the fan air inlets. With this, airflow resistance can be reduced, and the airflow can be sucked into the heat exchanger in a large range. Also with this, reduction in power consumption of the motor and reduction in noise level can be achieved.
In a case where the plurality of blower fans are controlled so as to have mutually different numbers of revolutions of the fans, it is possible to suppress beat noise between adjacent fans caused in a case where the fans are controlled so as to have the same number of revolutions (for example, in a case where the plurality blower fans are driven by one motor), and hence audibility can be enhanced. Further, in a case where an installation position is set to a corner section of a room so that an air outlet space for one of the blower fans is narrow and an air outlet space for another one of the blower fans is wide, when the fans are controlled so as to have the same number of revolutions, there is a fear in that airflow resistance of one of the blower fans becomes extremely high, to thereby cause increase in power consumption of the motor. However, the fans are controlled so as to have mutually different numbers of revolutions of the fans, and thus airflow resistance can be adjusted. Further, power consumption of the motor can be reduced.
The fan casing includes the frame body and at least one side wall surface removably mounted to the frame body, and hence a side surface of the fan casing can be opened and closed. Accordingly, there is an advantage in that replacement work is easily performed even if the impeller or the motor is broken or damaged. Further, strength can be ensured owing to the frame body, and hence the fan casing does not need to be thick entirely. Thus, weight and an amount of a material can be reduced. In addition, a material for a part of wall surfaces forming the fan casing can be changed or varied from a material for the frame body and the other wall surfaces. For example, when a reinforced transparent resin is employed as a material for a part of wall surfaces, an operation state of the fan can be easily checked only through removal of a side plate of the main body, and hence a construction property and a maintenance property can be enhanced.
Further, the motor support is positioned closer to the side on which the fan air outlet is formed than the main plate of the impeller. That is, this leads to separation of the motor support from the fan air inlet, and thus it is possible to obtain a mode in which the air passes around the motor support at a stage where the wind velocity is reduced in a route of the airflow from the fan air inlet to the fan air outlet. Also with this, reduction in airflow resistance and suppression of degradation of noise level can be achieved. Further, the airflow toward the fan air outlet can be deflected by the motor support toward the fan air outlet. That is, the motor support can exert a function of supporting the motor, and a function as an air guiding plate.
Further, side surfaces of the fan casing include at least one flat surface. As an example of the fan casing, in the first embodiment, the fan casing exhibits a rectangular shape in plan view. Regarding this, for example, in a case where the fan casing has a cylindrical shape and a side wall surface of the fan casing exhibits a circular shape in plan view, the airflow circles, and hence the airflow is not smoothly deflected toward the fan air outlet by the side wall surface of the fan casing. As a result, there is a fear in that an air blowing amount is reduced, and thus power consumption of the motor may be deteriorated. On the other hand, in the first embodiment, as described above, the fan casing exhibits a rectangular shape in plan view, and hence four surfaces and four corners are secured on the side surfaces of the fan casing. The airflow blown out from the impeller air outlet is prevented from circling, and is effectively and reliably deflected toward the fan air outlet by large flat surfaces serving as the side wall surfaces. Accordingly, also with this, it is possible to obtain an effect of reducing power consumption of the motor.
Further, the heat exchanger has a V-shape, that is, has a shape including at least one bent portion. Thus, an area of the heat exchanger can be enlarged, and heat transferring performance is enhanced. Accordingly, even in a case of the same air blowing amount, a heat exchange amount can be increased. Therefore, in a case of the same heat exchange amount, an air blowing amount can be further reduced, and power consumption of the motor can be reduced.

Second Embodiment

Next, an air conditioning apparatus according to a second embodiment of the present invention is described. FIG. 8 is a view illustrating the second embodiment and corresponding to FIG. 5. Note that, the second embodiment has the same configuration as that of the above-mentioned first embodiment except for components to be described below.
A fan casing 210 of a blower fan 207 according to the second embodiment includes a pair of rounded portions 223 a and a pair of chamfered portions 233 b at portions thereof corresponding to corners of a rectangular shape with reference to the rectangular shape of the fan casing 110 in plan view.
Also in the second embodiment, the same advantage as that of the first embodiment can be obtained. Further, also in the second embodiment, the side surfaces of the fan casing include at least one flat surface, and hence similarly to the first embodiment, the airflow blown out from the impeller air outlet is prevented from circling, and is effectively and reliably deflected toward the fan air outlet by large flat surfaces serving as side wall surfaces. In addition, in the second embodiment, at least one chamfered portion is formed at a portion of the fan casing corresponding to a corner of a rectangular shape with reference to the rectangular shape of the fan casing 110 in plan view. Accordingly, piping and wiring can be provided in a space formed outside the chamfered portion of the fan casing, and upsizing of a dimension of the unit can be suppressed. That is, it is possible to obtain an air conditioning apparatus that is easily downsized while realizing reduction in power consumption of the motor along with reduction in airflow resistance.

Third Embodiment

Next, an air conditioning apparatus according to a third embodiment of the present invention is described. FIG. 9 is a view illustrating the third embodiment and corresponding to FIG. 2. Note that, the third embodiment has the same configuration as that of the above-mentioned first or second embodiment except for components to be described below. As an example, FIG. 9 illustrates a case where the third embodiment is implemented in combination with the above-mentioned first embodiment.
In the third embodiment, a heat exchanger 304 includes the two heat exchanger forming sections 104 a arranged in an inverted V-shape. Below a lower end of each of the heat exchanger forming sections 104 a, a drain pan 314 is provided.
Also in the third embodiment, the same advantage as that of the corresponding first or second embodiment can be obtained. In addition, in the third embodiment, the heat exchanger has an inverted V-shape, and hence it is possible to realize such a layout that the fan air inlet is arranged in a space on a side of an interval between the heat exchanger forming sections. The drain pan is not positioned near the fan air inlet nor directly above the fan air inlet, with the result that reduction in airflow resistance and suppression of a drift are accelerated. Also with this, reduction in power consumption of the motor and reduction in noise level can be achieved.
Further, the above-mentioned feature of the third embodiment is not limited to forming the heat exchanger into an inverted V-shape. FIG. 10 is a view illustrating a modified example of the third embodiment and corresponding to FIG. 3, and FIG. 11 is a view illustrating the modified example of the third embodiment and corresponding to FIG. 2.
As the third embodiment, a heat exchanger 404 includes four heat exchanger forming sections 104 a arranged in an M-shape. Below a lower end of each of the heat exchanger forming sections 104 a, a drain pan 414 is provided. Note that, the above-mentioned M-shape is viewed from a lateral side orthogonal to such an aligning direction of the blower fans that the plurality of blower fans appear to overlap each other.
Also in this modified example, similarly to a case where the heat exchanger having an inverted V-shape illustrated in FIG. 9 is provided, the drain pan is not positioned near the fan air inlet nor directly above the fan air inlet, and thus reduction in airflow resistance and suppression of the drift can be achieved.
Although the details of the present invention are specifically described above with reference to the preferred embodiments, it is apparent that persons skilled in the art may adopt various modifications based on the basic technical concepts and teachings of the present invention. For example, a single blower fan may be used.

REFERENCE SIGNS LIST

- 100 unit main body, 104, 304, 404 heat exchanger, 104 a heat exchanger forming section, 107, 207 blower fan, 107 a fan air inlet, 107 b fan air outlet, 108 impeller, 108 a blade, 108 b side plate, 108 c main plate, 108 d impeller air inlet, 108 e impeller air outlet, 109 motor, 110, 210 fan casing, 110 a, 210 a frame body, 110 b side wall surface, ill motor support.

Claims

1. An air conditioning apparatus, comprising:

a unit main body;

a heat exchanger; and

at least one blower fan,

wherein the heat exchanger is arranged on an upstream side of the blower fan,

wherein the blower fan comprises an impeller, a motor, and a fan casing,

wherein the impeller comprises a turbofan that sucks air from an upper portion thereof and blows out the air radially outward,

wherein a rotation axis of the impeller is directed to a unit height direction,

wherein the fan casing has a fan air inlet formed in an upper surface thereof, and has a fan air outlet formed in a lower surface thereof, and

wherein an impeller air outlet of the impeller is covered by side surfaces of the fan casing,

wherein the impeller comprises a plurality of blades, a side plate having a ring shape, and a main plate,

wherein the side plate is positioned on the fan air inlet side, and the main plate is positioned on the fan air outlet side, and

wherein an outer diameter (φDs) of the side plate is larger than an outer diameter (φDm) of the main plate.

2. An air conditioning apparatus according to claim 1, wherein the blower fan is arranged below the heat exchanger.

3-4. (canceled)

5. An air conditioning apparatus according to claim 1, wherein the air conditioning apparatus comprises a plurality of blower fans.

6. An air conditioning apparatus according to claim 5, wherein the plurality of blower fans are arranged with an interval in a widthwise direction.

7. An air conditioning apparatus according to claim 5, wherein the plurality of blower fans are controlled so as to have mutually different numbers of revolutions of the fans.

8. An air conditioning apparatus according to claim 1, wherein the fan casing comprises a frame body, and at least one side wall surface is removably mounted to the frame body.

9. An air conditioning apparatus according to claim 1,

wherein the blower fan comprises a motor support, and

wherein the motor support is positioned on the fan air outlet side of the main plate of the impeller.

10. An air conditioning apparatus according to claim 1, wherein the side surfaces of the fan casing comprise at least one flat surface.

11. An air conditioning apparatus according to claim 10, wherein the fan casing comprises at least one chamfered portion, with reference to a rectangular shape of the fan casing in plane view, at a portion corresponding to a corner of the rectangular shape.

12. An air conditioning apparatus according to claim 1, wherein the heat exchanger has a shape comprising at least one bent portion.

13. An air conditioning apparatus according to claim 1, wherein the heat exchanger has an inverted V-shape or an M-shape.

14. An air conditioning apparatus, comprising: