WO2016095838A1

WO2016095838A1 - Fan housing

Info

Publication number: WO2016095838A1
Application number: PCT/CN2015/097810
Authority: WO
Inventors: 狄义波; 孙卫亮; 靳杰
Original assignee: 特灵空调系统(中国)有限公司; 特灵国际有限公司
Priority date: 2014-12-19
Filing date: 2015-12-18
Publication date: 2016-06-23
Also published as: CN204553343U; CN107208656A

Abstract

A fan housing (10), comprising: an air intake volute housing (11) for air intake, a hollow wheel unit (14) provided at the center of the air intake volute housing (11), and a diffusion tube (12) connected to the air intake volute housing (11) and used for air outflow; and at least the width of the air intake volute housing (11) in the fan housing (10) is continuously variable. Compared to an air conditioning indoor unit employing a traditional fan housing, the air conditioning indoor unit employing said fan housing (10) effectively reduces rotational speed of the fan and noise.

Description

Fan housing

Technical field

The utility model relates to a fan casing for diffusing air, and more particularly to a centrifugal fan used in an indoor unit of an air conditioner.

Background technique

Multi-blade centrifugal fans are widely used in variable coolant flow (VRF) products, especially in indoor units of air conditioners. It provides enough air to exchange heat with the coils and then cool or heat the various living places. The fan has the advantages of small volume, large air volume, high pressure, low noise, compact structure and convenient installation, so it is especially suitable for ventilation and ventilation places with strict noise requirements and large air volume variation.

Figure 1 illustrates the configuration of a conventional centrifugal fan in an indoor unit of an air conditioner. A large capacity air conditioner or heat pump typically requires more than one fan to be used in an indoor unit to provide improved airflow fluid flow characteristics. Centrifugal fans generally include components such as a fan casing, an impeller, an air inlet, and an outer rotor motor. As can be seen in Figure 1, the width W1 of the fan casing is a fixed value. In other words, the fan casing (especially its volute portion) has a constant width W1 along its length or along its axis of rotation.

2 is a schematic view showing the comparison between the width W1 of the fan casing and the width W2 of the coil. Although only two fan casings are shown, the outlet only covers a small portion of the coil width W2. In other words, if the ratio of W1/W2 is used to represent the ratio of the fan outlet area to the upstream area of the coil, it is clear that the ratio is within a small range. This results in a large mixing loss when the cross section of the fan is expanded, and the air flow velocity distribution on the coil is not uniform, so it is necessary to provide sufficient pressure to compensate for the above loss. However, this in turn leads to an increase in the fan speed and an increase in noise, which cannot meet the requirements for use.

Therefore, there is a need to design an improved fan casing such that the air conditioner indoor unit employing the improved fan casing can effectively reduce the fan speed and reduce the noise level as compared with the air conditioner indoor unit using the conventional fan casing.

Utility model content

The object of the present invention is to provide an improved fan casing. The air conditioner indoor unit adopting the improved fan casing can effectively reduce the fan speed and reduce the noise level compared with the air conditioner indoor unit adopting the conventional fan casing.

The utility model provides a fan casing, comprising: an inlet volute for airflow entering, a hollow wheel portion at the center of the inlet volute; and a diffusion pipe, the diffusion pipe is connected with the inlet volute and the airflow flows out Wherein at least the width of the inlet volute is continuously varied in the fan casing.

In a preferred embodiment, the width of the inlet volute may gradually increase as its outer circumference extends in the direction of the helix. Alternatively, the widths of the intake volute and the diffuser may gradually increase as their outer circumference extends. In the latter case, the ratio d2/d1 of the width of the fan casing at the second position to the width of the fan casing at the first position is 1.05-1.30, wherein the first position is the starting position of the intake volute The second position is a position reached after the intake volute extends 360° from the first position in the spiral direction.

Further, the ratio d3/d2 of the width of the fan casing at the third position to the width of the fan casing at the second position is 1.05-1.30, wherein the third position is the outlet position of the diffuser.

In addition, the width of the fan casing is gradually increased in a linear manner, and the spiral along which the outer periphery of the inlet volute extends forms an inclination angle α with the longitudinal direction of the fan casing, wherein the inclination angle α may be 5-30°.

In another aspect, the fan casing forms a C-shaped throat having a first radius R1 at both sides of the fan casing and a second radius R2 at an intermediate position of the fan casing 10, wherein the second radius and the first radius The ratio R2/R1 can be 1.5-2.5.

In another preferred embodiment, the outer edge of the intake volute may be chamfered to 1/8 to 1/10 of the diameter of the hollow wheel portion of the intake volute.

In still another preferred embodiment, the length L of the outer circumferential edge of the diffuser tube may be 0.7 to 1.2 times the diameter of the hollow wheel portion of the intake volute.

Compared with the conventional fan casing, the fan casing of the present invention has the following advantages:

Since at least the width of the inlet volute portion of the fan casing is continuously increased, the outlet area of the fan volute is increased, thereby increasing the ratio W1/W2 of the width W1 of the fan casing to the width W2 of the coil, thereby saving More dynamic pressure.

In addition, the applicant has designed the widths d1, d2, and d3 of the first, second, and third positions of the fan casing to be d2/d1=1.05-1.30 and d3/d2=1.05-1.30 through a number of experiments. With the above design, the distribution of the gas flow in the vicinity of the coil can be optimized to the utmost without minimizing the flow separation, and the average speed and noise generated at the outlet of the casing can be minimized.

DRAWINGS

In order to further explain the structure of the fan casing of the present invention and its technical effects, the following will be combined with the accompanying drawings. The present invention is described in detail with reference to specific embodiments, wherein:

Figure 1 shows the configuration of a conventional centrifugal fan in an indoor unit of an air conditioner;

Figure 2 is a schematic view showing the comparison between the width of the fan casing of Figure 1 and the width of the coil;

Figure 3 is a front elevational view of the fan casing of the present invention;

Figure 3a is a cross-sectional view taken along line A-A of Figure 3;

Figure 4 is a plan view of the fan casing of Figure 3;

Figure 5 is a left side view of the fan casing of Figure 3;

Figure 6 shows the width dimensions of the fan casing having a variable width in a first position, a second position, and a third position;

Figure 7 shows the width of the gap at the throat of the fan casing;

8a and 8b are schematic cross-sectional views showing a fan speed and an air volume flow rate tested in an air flow test using an air conditioner indoor unit of the present invention, and a conventional air conditioner indoor unit;

Figures 8c and 8d show schematic bar graphs of the noise and fan speeds tested in the noise test of the air conditioner indoor unit using the fan casing of the present invention and the conventional air conditioner indoor unit.

detailed description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the fan casing of the present invention will be described with reference to Figs. 3, 3a, 4-7, 8a-8d, wherein the same reference numerals denote the same components.

3 is a front view of the fan casing 10 of the present invention, and FIGS. 4 and 5 are a plan view and a left side view, respectively, of the fan casing of FIG. As shown in Fig. 3, the fan casing 10 is composed of an intake volute 11 for air inflow and a diffuser pipe 12 for air outflow. As can be seen from Fig. 3, the intake volute 11 has a shape similar to a snail shell, and is provided with a hollow wheel portion 14 at its center, the outer circumference of which surrounds the circumference of the wheel portion 14 along a spiral (for example, Archimedes spiral or The logarithmic spiral line extends in the direction. The diffuser tube 12 has a flare-like shape with its outer periphery extending tangentially at the junction with the inlet volute 11. In Fig. 3, the length of the tangential extension of the outer circumference of the diffuser tube 12 is indicated by L. In order to increase the exit area, L may be designed to be 0.7-1.2 times the diameter of the hollow wheel portion 14 of the intake volute 11.

The above is merely a brief introduction to the shape design of the intake volute 11 and the diffuser tube 12. It will be understood by those skilled in the art that any known variations on the shape design of the intake volute and the diffuser should fall within the present specification. The scope of protection of utility models.

The main feature of the fan casing of the present invention is different from the conventional fan casing: in the fan casing At least 10 of the inlet volutes 11 have a continuously varying width. In a preferred embodiment of the present invention, the width of the inlet volute 11 of the fan casing 10 gradually increases as its outer circumference extends in the direction of the helix. In another preferred embodiment of the present invention, the widths of the inlet volute 11 and the diffuser tube 12 of the fan casing 10 gradually increase as their outer circumference extends.

Referring to Figure 6, there is shown the width dimension of the fan casing 10 in the first position (a, a'), the second position (b, b') and the third position (c, c'). It can be seen that the fan casing 10 has the smallest width at the first position and the largest at the third position.

Specifically, the "first position (a, a')" as defined in the present application means the initial position of the intake volute 11, that is, the position where the outer peripheral edge of the spiral of the intake volute 11 has the maximum curvature. The "second position (b, b')" as defined in the present application refers to a position reached after the intake volute 11 extends 360 degrees in the spiral direction around the center of the wheel portion 14 from the first position. The second position substantially coincides with the first position at the throat 13 of the fan casing 10. The "third position (c, c')" as defined in the present application refers to the exit position of the diffuser tube 12.

As can be clearly seen from Fig. 6, if the width dimension of the fan casing 10 at the first position (a, a') is defined as d1, the width dimension of the fan casing 10 at the second position (b, b') is defined as D2, and positioning the distance between the first position and the second position (such as a and b) along the width of the fan casing as d', then d2>d1 and d2=d1+2d' can be obtained. It has been found through experiments that the ratio of d2/d1 is preferably between 1.05 and 1.30.

If the width dimension of the fan casing 10 in the second position (b, b') is defined as d2 and the width dimension of the fan casing 10 in the third position (c, c') is defined as d3, d3 > d2 can be obtained. It has also been found through experiments that the ratio of d3/d2 is also preferably between 1.05-1.30.

In addition, as shown in FIG. 5, since the width d1 of the fan casing 10 at the first position is gradually increased in a linear manner to the width d2 at the second position, the spiral of the outer circumference of the intake volute 11 is extended. An inclination angle α is formed with the longitudinal direction of the fan casing 10. In the present embodiment, the value of the inclination angle α ranges from 5 to 30°. Of course, it is well known to those skilled in the art that the width d1 of the fan casing 10 at the first position can be gradually increased in a quadratic function to the width d2 at the second position, and these variations will fall into the present application. New range of protection.

Referring to Figure 3a, a cross-section of the fan casing taken along line A-A of Figure 3 is shown. It can be seen that the throat 13 has a C-shaped end face structure which exhibits a mid-high and low-end configuration along the width of the fan casing (also visible in Figure 6).

Returning to Figure 3, it can be seen that the C-shaped end throats 13 have different radii on both sides and intermediate portions of the fan casing 10. Specifically, the C-shaped end face throat 13 has a minimum radius R1 at both sides of the fan casing 10 and a maximum radius R2 at the intermediate position of the fan casing 10, wherein the ratio of R2/R1 falls within the range of 1.5-2.5. .

FIG. 7 shows the gap width t between the throat 13 of the fan casing 10 and the hollow wheel portion 14. It will be understood by one of ordinary skill in the art that if the gap width t between the wheel portion 14 and the throat portion 13 is too large, the average velocity of the airflow at the cross-section of the throat will be reduced. Although various modifications have been made to the shape of the throat 13 in the prior art to reduce separation and/or backflow of airflow in the throat region, the above average speed is still inevitably lowered and causes an increase in noise. By using the C-shaped end face throat of the fan casing of the present invention, it is possible to reduce the rotational impact of the airflow in the throat region, especially the intermediate portion of the throat along the width direction of the fan casing, thereby reducing the noise generated thereby.

In still another preferred embodiment of the present invention, the outer edge of the fan casing 10 may be chamfered such that both side surfaces of the fan casing 10 become curved. By the above improvement, it is possible to reduce the loss of the guide air flowing into the air conditioner indoor unit and passing over the fan casing 10. It has been experimentally found that the outer edge of the intake volute 11 can be chamfered to be 1/8 to 1/10 of the diameter of the hollow wheel portion 14 of the intake volute 11.

In order to determine whether the technical effect obtained by the fan casing 10 of the present invention is significantly higher than that of the conventional fan casing, the applicant applies the air conditioner indoor unit of the fan casing 10 of the present invention under the same conditions of the outlet static pressure of 30 Pa. Air flow testing and noise testing were performed with an air conditioner indoor unit using a conventional fan casing. In Figures 8a to 8d, the comparison results of the above tests are shown, respectively.

It can be seen that in the air flow test shown in Figures 8a and 8b, the air conditioner indoor unit using the fan casing 10 of the present invention has a larger air volume flow rate (compared to an air conditioner indoor unit using a conventional fan casing) Increased rotation speed of 23 m ³ /hr or more) and lower by 54 rpm or more compared to an air conditioner indoor unit using a conventional fan casing. In the noise test shown in Figures 8c and 8d, the air conditioner indoor unit using the fan casing 10 of the present invention has a lower noise level (a reduction of 1.6dBA or more compared to an air conditioner indoor unit using a conventional fan casing) ) and lower rotational speed (70 rpm or more compared to an air conditioner indoor unit using a conventional fan casing). In the above test, the motor input energy consumed by the air conditioner indoor unit using the fan casing 10 of the present invention is substantially the same level (about 52-54 W) as compared with the air conditioner indoor unit using the conventional fan casing.

In addition, the applicant also prototyped two other larger air conditioner indoor units and conducted noise tests, which showed lower noise levels (1.6dBA and 2.3dBA or more, respectively).

It can be seen that by replacing the conventional fan casing used in the indoor unit of the air conditioner with the improved fan casing of the utility model, the noise can be effectively reduced, thereby meeting the demand of users with high requirements for environmental quietness. .

Although the structure and technical effects of the fan casing of the present invention have been further described above in connection with a number of embodiments, those skilled in the art will appreciate that the above examples are for illustrative purposes only and are not intended to be useful. New restrictions. Therefore, the present invention may be modified within the spirit and scope of the claims, and these modifications are intended to fall within the scope of the appended claims.

Claims

A fan casing (10) comprising:

An intake volute (11) for airflow entering, the center of the intake volute (11) being provided with a hollow wheel portion (14);

a diffuser tube (12) connected to the inlet volute (11) for airflow

It is characterized in that at least the width of the intake volute (11) in the fan casing (10) is continuously varied.
A fan casing (10) according to claim 1, characterized in that the width of the inlet volute (11) gradually increases as its outer circumference extends in the direction of the helix.
The fan casing (10) according to claim 2, wherein the width of the intake volute (11) and the diffuser (12) gradually increase as the outer circumference thereof extends.
The fan casing (10) according to claim 3, wherein a width (d2) of the fan casing (10) at the second position and a width of the fan casing (10) at the first position ( The ratio (d2/d1) of d1) is 1.05-1.30, wherein the first position is a starting position of the intake volute (11), and the second position is the intake volute (11) a position reached after extending 360° in the spiral direction from the first position.
The fan casing (10) according to claim 4, wherein a width (d3) of the fan casing (10) at the third position and a width of the fan casing (10) at the second position ( The ratio (d3/d2) of d2) is 1.05-1.30, wherein the third position is the exit position of the diffusion tube (12).
A fan casing (10) according to claim 2, wherein said fan casing (10) has a width that increases gradually in a linear manner, and a spiral along which the outer periphery of said inlet volute (11) extends An oblique angle (α) is formed with the longitudinal direction of the fan casing (10).
The fan casing (10) according to claim 6, wherein said inclination angle (α) is 5-30°.
The fan casing (10) according to claim 6, wherein said fan casing (10) forms a C-shaped throat (13), and said throat (13) is in said fan casing (10) The side position has a first radius (R1) having a second radius (R2) at an intermediate position of the fan casing (10), wherein the ratio of the second radius to the first radius (R2/R1) is 1.5-2.5.
The fan casing (10) of claim 1 wherein said intake volute (11) The outer edge is chamfered to 1/8 to 1/10 of the diameter of the hollow wheel portion (14) of the intake volute (11).
The fan casing (10) according to claim 1, wherein a length (L) of a tangential extension of an outer circumference of the diffuser pipe (12) is a hollow wheel portion of the intake volute (11) ( 14) 0.7 to 1.2 times the diameter.