JPS6122177Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a ceiling-suspended type with a built-in mixed flow fan, etc.
This invention relates to a ceiling-mounted air conditioner that is installed on the ceiling.

Generally, as a fan used in an air conditioner, due to the difference in the direction of accelerating the sucked air,
There are three types: axial flow fans, mixed flow fans, and centrifugal fans.

When designing an air conditioner, these three
The criterion for selecting which type of fan to use is determined by the value of specific speed (ηs) required for the air conditioner. However, specific speed (η _S ) = (N・Q〓/H〓) N (rpm): Fan rotation speed Q (m ³ /min): Air volume H (m): Head (=P _T /γ) In other words, As is clear from the relationship between the specific speed (η _S ), total pressure efficiency (η _T ), and specific noise shown in Figure 4, when the specific speed (η _S ) is 600 or less, the centrifugal It is best to use a diagonal flow fan indicated by a broken line b when the number is 800 to 1200, and an axial flow fan indicated by a solid line c when the number is 1200 or more.

However, recently, in order to meet the demands for higher efficiency, thinner profile, and lower noise, both indoor and outdoor air conditioners have been increasing in specific speed (η _S ) from 800 to 1200. As a result, the use of mixed flow fans is being considered. In particular, in the case of ceiling-mounted devices, there is a noticeable trend toward thinner devices because they are required to reduce the feeling of pressure.

For this reason, an air conditioner incorporating a mixed flow fan has been proposed (see Japanese Utility Model Application Publication No. 51748/1983). In this device, a mixed flow fan is disposed in the air passageway between the suction port and the blowout port on the side surface of the casing, facing the blowout port, and a heat exchanger is placed upstream of the mixed flow fan. .

However, in the proposed method, since the mixed flow fan is simply placed downstream of the heat exchanger and facing the outlet, the movement of the suction air near the impeller outlet is lower than in the case of an axial flow fan. The pressure is large, and as a result, the static pressure efficiency decreases and the air volume decreases, and in order to obtain a predetermined air volume, it is necessary to increase the shaft power, and there is a problem that a large amount of noise is generated. In addition, for this reason, in order to ensure the performance of the mixed flow fan, it is possible to form a dynamic pressure recovery section toward the front of the outlet of the air conditioner, but in this case, the thickness will increase and the structure will become thinner. will not be possible.

The present invention has been made in view of this point, and by using a diagonal flow fan having a radius transition type diffuser at the impeller outlet, recovery of the static pressure of the dynamic pressure of the suction air is promoted, and the diagonal flow fan is improved. By reducing the required shaft power of the flow fan and reducing noise, furthermore, by arranging a heat exchanger around the periphery of the diffuser, a substantially uniform wind speed can be achieved after the static pressure is restored. This ceiling-mounted type allows air to flow through the heat exchanger to further reduce noise and improve heat exchange efficiency, while also making it thinner and allowing air to be blown out in a nearly horizontal direction to improve airflow distribution. The aim is to provide air conditioners.

That is, the present invention has a built-in mixed flow fan having an impeller in which a plurality of blades that produce mixed flow acceleration are planted on the peripheral wall surface of a truncated conical hub, and the mixed flow fan is mounted on the front surface of the hub. The differential user has a suction port facing the impeller, and an omnidirectional open path is formed between the front plate and the rear plate located behind the impeller, which is parallel or expands toward the outer circumference. At the same time, a heat exchanger is disposed around the peripheral edge of the diff user, and the air sucked by the mixed flow fan is blown out in multiple directions in the radial direction through the diff user.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

1 and 2 show a ceiling-suspended indoor unit A of a separate type air conditioner according to an embodiment of the present invention, 1 is a casing, and inside the casing 1 is a truncated conical hub 3. A mixed flow fan 6 having an impeller 5 in which a plurality of blades 4, 4, . The blade 5 is attached to the center of the inner surface of the rear plate 1a of the casing 1 in close proximity to the front of the rear plate 1a.

A front plate 8a and a rear plate 1 of the casing 1 are located downstream of the outlet of the impeller 5 of the mixed flow fan 6.
A differential user 8 consisting of a rear plate 8b which also serves as a
is installed. The differential user 8 has a circular suction port 9 facing the impeller 5 of the mixed flow fan 6 in the center of its front plate 8b, and a hub of the impeller 5 from the peripheral edge of the suction port 9. 3. An inclined part 9a that is inclined parallel to the circumferential wall surface (that is, in the diagonal flow direction) is formed, and an omnidirectional open passage 10 that is open parallel to the radial direction is formed between the front plate 8a and the rear plate 8b. Therefore, the mixed flow fan 6 is configured to blow out the air sucked in from the suction port 9 in multiple directions in the radial direction. Further, the omnidirectional open path 10 of the differential user 8 is formed to expand toward the outer circumference, and a fin coil such as a cross fin coil or a wind fin coil is provided at the periphery of the differential user 8. A heat exchanger 2 is provided which performs a heat exchange function.

Therefore, in the above embodiment, the air sucked by the diagonal flow fan 6 is accelerated in a diagonal flow manner, and then
Since air is blown out in multiple radial directions from the outlet of the impeller 5 through a diffuser 8 having an omnidirectional open passage 10 parallel to the radial direction, even if the dynamic pressure of the sucked air becomes large near the outlet of the impeller 5 of the diagonal flow fan 6, the static pressure recovery of the dynamic pressure is promoted as the air passes through the omnidirectional open passage 10, thereby increasing the static pressure efficiency and enhancing the scenery, reducing the driving force required for the diagonal flow fan 6, and reducing noise.

Moreover, the omnidirectional open path 1 of the differential user 8
Since the air that has passed through 0 is blown out in multiple radial directions and in a substantially horizontal direction, it is possible to improve airflow distribution by blowing out in a substantially horizontal direction, which is required for ceiling-mounted models, and also to reduce the depth dimension. It is possible to achieve a thinner design. In addition, when installing indoor unit A along the ceiling surface, casing 1
There is no need to create a gap between the rear panel 1a and the ceiling to make it easier for air to blow out, and it can be installed in close contact with the ceiling, saving space. .

Furthermore, by arranging the heat exchanger 2 at the peripheral edge of the differential user 8, the depth dimension of the indoor unit A is increased by the thickness of the heat exchanger 2 and the distance between the heat exchanger 2 and the mixed flow fan 6. This makes it possible to further reduce the thickness and space, and is particularly effective for ceiling-mounted types where it is desired to reduce the feeling of pressure. Moreover, since the air flows through the heat exchanger 2 at a substantially uniform wind speed after the static pressure is restored,
It is possible to further reduce noise and improve the efficiency of heat exchange.

Specifically, we measured changes in shaft power and noise with respect to changes in air volume for a conventional mixed flow fan without a differential user and a mixed flow fan according to the present invention, which can obtain the same air volume with the same static pressure value. death,
The results are shown in FIG. As is clear from FIG. 3, the mixed flow fan according to the present invention indicated by the solid line A is
It can be seen that the shaft power and noise can be significantly reduced compared to the conventional mixed flow fan shown by the broken line B. In addition, the dashed line C in FIG. 3 shows the relationship between static pressure and air volume when the rotation speed of the conventional mixed flow fan is the same as the rotation speed of the mixed flow fan according to the present invention. By comparing the dashed-dotted line C and the solid line A, it can be seen that the mixed flow fan according to the present invention can significantly increase the air volume compared to the conventional mixed flow fan.

In the case of the above embodiment, the air blown from the outlet of the impeller 5 passes through the differential user 8 and reaches the heat exchanger 2 while drawing a logarithmic spiral. Although it depends on the degree of expansion, since the air blown out at an angle in the circumferential direction with respect to the radial direction passes through the heat exchanger 2, the fine-coil type of the heat exchanger 2 has a cross-sectional shape to reduce collision loss. A wound fin coil is preferable to a fin coil.

Furthermore, in the above embodiment, the indoor unit of a separate type air conditioner was described, but recent outdoor units of separate type air conditioners are designed to have a thin trunk shape in order to save space. is increased, and the specific speed is 800 to 1200 compared to the conventional approximately 2500.
Therefore, it can of course be applied to outdoor units as well.

Further, in the embodiment described above, the rear plate 1b of the casing 1 also serves as the rear plate 8a of the differential user 8, but it goes without saying that these may be formed separately.

As explained above, according to the present invention, a diagonal flow fan having a built-in impeller formed of a plurality of blades that generate diagonal flow acceleration is planted on the peripheral wall surface of a truncated conical hub, and The face plate has a suction port facing the impeller of the mixed flow fan, and the omnidirectional open passage is parallel to or widens in the outer circumferential direction between the front plate and a rear plate located behind the impeller. In addition to providing a differential user formed with
A heat exchanger is disposed around the periphery of the diff user, and the air sucked in by the mixed flow fan is blown out in multiple radial directions through the diff user, thereby achieving high efficiency by reducing the required driving force. In addition, it is possible to reduce the noise level, reduce the thickness, save space, and improve the airflow distribution.
Furthermore, by arranging the heat exchanger at the peripheral edge of the diffuser, air flows through the heat exchanger at a substantially uniform air speed after the static pressure is restored, further reducing noise and improving heat exchange efficiency. In addition, it is possible to further reduce the thickness of the heat exchanger by the thickness of the heat exchanger, and thus it is particularly effective for ceiling installation type.

[Brief explanation of the drawing]

1 to 4 show an embodiment according to the present invention, FIGS. 1 and 2 are respectively a perspective view and a vertical sectional view of an indoor unit of the embodiment, and FIG. 3 is a change in shaft power and noise with respect to air volume. Measurement result diagram showing 4th
The figure is an explanatory diagram showing optimal fins depending on specific speed. 2... Heat exchanger, 3... Hub, 3a... Peripheral wall surface, 4... Vane, 5... Impeller, 6... Mixed flow fan, 8... Diff user, 8a... Front plate, 8b
... Rear plate, 9 ... Suction port, 10 ... Omnidirectional open path.

Claims (1)

[Scope of utility model registration request] A mixed flow fan 6 having an impeller 5 in which a plurality of blades 4, 4, . Impeller 5 of mixed flow fan 6
An omnidirectional open passage 10 is formed between the front plate 8a and a rear plate 8b located behind the impeller 5, which is parallel or expands toward the outer circumference. A diff user 8 is provided, and a heat exchanger 2 is installed around the periphery of the diff user 8.
A ceiling-mounted air conditioner characterized in that the air sucked by the mixed flow fan 6 is blown out in multiple radial directions via the differential fan 8.