JPH02166323A - Airconditioning device - Google Patents

Abstract

PURPOSE:To substantially improve air conditioning capacity, to reduce the generation of noise and a consumption power, and to prevent the generation of rasping noise by a method wherein the outer diameter of the side plate of an impeller or an outer plate is increased to a value higher than that of a blast blade. CONSTITUTION:An outer peripheral edge 4a of a main plate 4 is extended over the outer diameter of the blade of an impeller 7, and is bent toward the upper end side of a heat exchanger 13. Meanwhile, a side plate 5 is also extended in a similar manner described above and curved toward the lower end side of the heat exchanger 13. Thereby, a free jet boundary line of discharge air formed to the back of the main plate 4 and the side plate 5 of the impeller is prevented from extending across only the central part of the heat exchanger 13. As a result, velocity of flow distribution of air introduced to the heat exchanger 13 is improved, an air flow rate is increased resulting from a decrease in draft resistance, and heat exchange efficiency is also improved. Further, simultaneously, since a low blast amount suffices for operation of a device, the generation of noise is reduced, and a drive power can be also saved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an air conditioner equipped with a blower consisting of a centrifugal fan.

(Prior art) Centrifugal fan-type blowers that are generally equipped with rotor blades use the lift of the rotor blades to achieve the ventilation function, which transfers kinetic energy to fluids such as air. It has extremely high transmission and conversion efficiency, and has been widely used as a blower for air conditioners, for example.

Recently, ceiling-embedded type air conditioners have become increasingly popular due to their advantages in terms of installation space and freedom in indoor design. In this type of air conditioner, for example, as shown in Japanese Patent Application Laid-Open No. 62-194128, among various types of blowers, centrifugal fans such as those mentioned above or a mixed flow fan, which is a type of them, are generally used from the viewpoint of the air direction conversion function. A fan is usually used.

However, among the air blowers, centrifugal fans, mixed flow fans, and the like have a drawback that their air blowing capacity is relatively lower than that of normal axial fans.

The problem will be explained below by taking as an example the case of a conventional air conditioner equipped with a centrifugal fan as shown in FIG.

In the figure, the reference numeral 30 includes a main plate 31 and a side plate 32, and between the main plate 31 and the side plate 32, a plurality of air blowing blades 33, 33...
This is a centrifugal fan composed of impellers 35 arranged radially. The centrifugal fan 30 is rotated in a horizontal direction at a predetermined rotational speed by a fan driving electric motor 36.

On the other hand, reference numeral 37 is an external casing that houses the centrifugal fan 30 in the center and supports a heat exchanger 38 around the outer periphery of the impeller 35. 39, and an air outlet 40 is formed at the outer peripheral edge of the lower side.

When the centrifugal fan 30 is rotated by the electric motor 36, the air sucked in at the air suction port 39 by the action of the impeller 35 flows as shown by the arrow and is supplied to the heat exchanger 38. After the heat is exchanged in the heat exchanger 38, the air is blown into the room from the air outlet 40.

(Problem to be Solved by the Invention) By the way, in the ceiling-embedded air conditioner configured as described above, the height H3 of the heat exchanger 38 (see Fig. 5) is equal to the given vertical fan space. In this case, the height Hl of the heat exchanger 38 is necessarily larger than the height H2 of the blades 33 of the impeller 35. becomes.

On the other hand, in such a centrifugal fan, noise reduction can be achieved by increasing the diameter of the impeller 35 to reduce the required number of revolutions; The outer ends are extremely close to each other.

As a result, the free jet boundary line FL of the blown air formed behind the main plate 31 and side plate 32 of the impeller 35 crosses the center of the heat exchanger 38 as shown in the figure, and is directed to the heat exchanger 38. There is a problem that the wind speed (flow speed) distribution of the wind speed (flow speed) deteriorates. This deterioration of the wind speed distribution is due to the fact that each blower blade is 33.33
(Fig. 6) and between the upper and lower ends of the blower blade 33 (7th
This occurs in combination with the deterioration of the wind speed distribution that also occurs in Figure). If the wind speed distribution deteriorates, the ventilation resistance will eventually increase, and the heat exchange amount of the heat exchanger 38 will decrease, so if you try to obtain a constant heat exchange amount, you will have no choice but to further increase the air flow, and the consumption will increase. This causes inconveniences such as increased power and noise.

In terms of noise, in the above configuration, a particularly large wind speed distribution as shown in FIG. Since it is blown out, it tends to interfere with the resistor behind it and produce harsh sounds (NZ, 2NZ, etc.) with large discrete frequencies.

(Problems to be Solved by the Invention) The present invention has been made for the purpose of solving the above-mentioned problems. For example, as shown in FIGS. 1 to 3, a multiple air blowing blades6.6.
- A centrifugal fan 8 that has an impeller 7 and blows air in a direction perpendicular or substantially perpendicular to the rotating shaft 9, and an air conditioning heat exchanger 13 disposed around the outer periphery of the impeller 7 of the centrifugal fan 8.
In an air conditioner comprising: an outer diameter of the side plate 5 or the main plate 4 of the impeller 7, the outer diameter of the side plate 5 or the main plate 4 of the impeller 7 is
It is characterized by being formed larger than the outer diameter of...

(Function) In the configuration of the air conditioner of the present invention, the outer diameter of the side plate 5 or main plate 4 of the impeller 7 constituting the centrifugal fan 8 is larger than the outer diameter of the blower blades 6,6, etc. of the impeller 7. Since the extension part is formed with a large extension, it is possible to realize the Coander effect of the air flow, and the flow velocity distribution of the blown air flow supplied to the heat exchanger is made uniform. be able to.

(Effect of the invention) Therefore, according to the air conditioner of the present invention, the centrifugal fan,
The air conditioning ability of an air conditioner using a mixed flow fan or the like can be substantially improved, and the noise and power consumption can be lower than that of conventional devices.

Further, since the generation of noise of discrete frequency components is suppressed, particularly harsh sounds are not generated.

(Embodiment) FIGS. 1 to 3 show, for example, a ceiling-embedded cassette type air conditioner according to an embodiment of the present invention.

First, FIG. 1 shows the overall structure of the ceiling-embedded air conditioner cassette body 10, and reference numeral 1 in the figure indicates an external casing of the ceiling-embedded air conditioner cassette body 10.

On the central lower surface of the outer casing l, there are a plurality of backward curved air blowers formed by radially bending the inlet side in the rotational direction between the upper main plate 4 and the lower side plate (shroud) 5. A centrifugal fan 8 equipped with an impeller 7 configured by disposing blades 6, 6, . . . is suspended via an electric motor 9 for driving the fan. The centrifugal fan 8 has a fitting part 4b for connection with the rotating shaft 9a of the driving electric motor 9 at the center of the main plate 4 side, and is fitted with the rotating shaft 9a of the electric motor 9 at the fitting part 4b. connected. As a result, when the electric motor 9 is driven, the impeller 7 of the centrifugal fan 8 rotates in the horizontal plane direction, sucking air in the direction of arrow (A) and causing the blower blades 6.
The lift generated in the part 6... sends it out in the centrifugal direction shown by the arrow (b).

On the other hand, the external casing 1 has an opening 11 of a predetermined size located at the air suction portion, and the opening 2 is configured as an air suction grill. Air outlet ports 12 and 12 are provided at the lower edge of the outer periphery of the outer casing 1 so as to be inclined in the diffusion direction.

Further, reference numeral 13.13 is a heat exchanger disposed around the outer periphery of the centrifugal fan 8 and supported on the bottom wall i4 of the outer casing 3. The airflow pushed out in the radial direction by the action of centrifugal force from the impeller 7 is heat exchanged in the heat exchanger 13, and then flows from the outlet 12.12 in the direction indicated by the arrow (
C) The air is blown out in the outward direction.

Incidentally, in this case, the upper surface 14a of the donut-shaped bottom wall portion 14 of the outer casing l is partitioned into an inner region 16a and an outer region 16b by a locking edge 15 that stands upward at a predetermined angle. The heat exchanger 13 is installed with a predetermined drain space 17 in the drain space 16b. The extending end 15a of the locking edge I5 corresponds to the outer peripheral extension 5a of the side plate 5 described above, and the air flow passage 18 continuous with the extension 5a is directed toward the air inlet of the heat exchanger 13. It is supposed to form.

Therefore, in the case of the configuration of this embodiment, the outer peripheral edge 4 of the main plate 4
a is extended longer than the outer diameter of the blades of the impeller 7 and is curved toward the upper end of the heat exchanger 13, and the side plate 5 is also extended in the same way to form the lower end of the heat exchanger 13. curved laterally.

Therefore, it is possible to give a sufficient coander effect to the airflow pushed out in the centrifugal direction by the above-mentioned upper and lower extensions, and if the heat exchanger I3 in the outer casing 1 of the air conditioner main body 10 is Even when the height of the blower blade 6 of the impeller 7 is smaller than the height H, the air flow pushed out from the impeller 7 can be spread over the entire area from the upper end to the lower end of the heat exchanger 13. This allows the material to be fed evenly and efficiently. Then, the flow velocity distribution between the respective blower blades 6, 6 (FIG. 2) and the flow velocity distribution between the upper and lower ends of the blower blade 6 (FIG. 3) are also made equal, which is greatly improved.

For this reason, it is no longer necessary to increase the outer diameter of the blades 6 and bring the blades 6 closer to the heat exchanger 13 as in the past, and the blades 6 are formed behind the main plate 4 and side plate 5 of the impeller. The free jet boundary line FL (see FIG. 5) of the blown air no longer crosses only the center of the heat exchanger 13. As a result, the flow velocity distribution of the air introduced into the heat exchanger 13 is improved, the ventilation resistance is reduced, the air flow rate is increased as shown in FIG. 4, and the heat exchange efficiency is also improved.

Furthermore, as a result, the amount of air blown can also be reduced, reducing noise and saving driving power.

Although the above embodiment has been explained using a centrifugal fan as an example, it goes without saying that the above effects can be achieved in exactly the same way even in the case of a mixed flow fan, a sirocco fan, etc. . In short, all types of centrifugal fans can achieve similar effects.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing the configuration of an air conditioner according to an embodiment of the present invention, FIGS. The figure is a graph showing the effect of improving air blowing capacity when using the structure of the embodiment shown in Fig. 1, Fig. 5 is a longitudinal sectional view showing the structure of a conventional air conditioner, and Figs. 6 and 7 are the same. FIG. 6 is an explanatory diagram similar to FIGS. 2 and 3, showing the effects of the configuration of the conventional air conditioner shown in FIG. 5; l... No. 4... 4a...- 5...◆ 5a...- 6... ・External casing, main plate, main plate extension, side plate, side plate extension, blower blade 7 ・ ・ 8・ ・ 9 ・ ・ 9a ・ 10 ・ 1 ・ 2 ・ 3 ・ 4 ・ 5 ・ a b 7 ・ Impeller Centrifugal fan drive electric motor Rotating shaft Air conditioner body opening Air outlet Heat exchanger Bottom wall retaining edge inside Area outside area drain space Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. It has an impeller (7) consisting of a plurality of blowing blades (6), (6), etc. arranged between the main plate (4) and the side plate (5), and is perpendicular or substantially perpendicular to the rotation axis (9). A centrifugal fan (8) that blows air in the direction and the impeller (7) of the centrifugal fan (8)
) and an air conditioning heat exchanger (13) disposed around the outer periphery of the impeller (7).
The outer diameter of the side plate (5) or main plate (4) of the impeller (7)
An air conditioner characterized in that the outer diameter of the blower blades (6), (6), etc. is larger than that of the air conditioner.