JPH11173646A - Air conditioning outlet grill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioning outlet grill capable of increasing the quantity of circulating air without increasing the air outlet opening area of the outlet grill and consumed power or noise. SOLUTION: A multiple-perforated plate 2 has a plurality of holes 21 with diameter d at regular hole pitches p. From the holes, a plurality of jets diverge at prescribed diverging angle A. A honeycomb core 3 is provided in the downstream side of the injecting direction of the plate 2 with a space dimension L from the plate 2 in a casing. The space dimension L is obtained by L=(p-d)/(2.tan A) so that the interference between the jets is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air-conditioning blow-out grill used for air-conditioning equipment.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, a blow grill 100 comprises a housing 101, a blade 102, and a damper or shutter 103 (hereinafter referred to as a damper 103). Are supplied continuously. The blowing direction can be changed by appropriately tilting and adjusting the direction of the blade 102. The amount of the blown air can be adjusted by the damper 103. The damper 103 is a multi-blade damper that rotates at a fulcrum 105 for pressure loss adjustment.
The damper 103 can be a parallel type, an opposing type with a smaller pressure loss (see FIG. 5), or a closed state. In addition, instead of the damper 103, a ventilation resistor (not shown) such as a perforated plate may be used for a ventilation portion in the blowout grill 100. As shown in FIG. 6, the net amount of air blown from the outlet grill 100 is set in consideration of the property that the air 106 discharged from the outlet grill 100 is drawn into and circulates through the circulating air 107 in the air conditioning area.

[0003]

However, when the required amount of air circulation is large, the opening area of the air outlet of the outlet grill 100 becomes large, and the power consumption of the air circulation fan of the air conditioning equipment increases. Further, there is a problem that noise and the like accompanying the increase. The present invention has been made in view of such a situation, and an object of the present invention is to provide an air-conditioning blowout grill that can increase the amount of air circulation without causing such a problem.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and has a perforated plate in which a plurality of holes having a diameter d are formed at a hole pitch p, and is disposed downstream of the perforated plate. Rectifying grid. The distance L between the perforated plate and the rectifying grid is L ≦ (p−d) / (2 · tan A). A is the spread angle, that is, the angle at which the fluid flow ejected from the hole spreads. The air-conditioning blowout grill further includes a perforated plate having a plurality of first holes formed therein, and a second air intake port for taking in air around a fluid flow ejected from the first holes.
The hole may be formed on the downstream side of the perforated plate.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an air-conditioning outlet grill according to the present invention will be described with reference to the drawings.
A first embodiment is shown in FIGS. FIG. 1 shows a blow-out grill 1 for air conditioning, and FIG.
FIG. 2B is an end view of the suction side 11, and FIG. 2 is a partially enlarged view of FIG. The blowout grill 1 includes a housing 12, a perforated plate 2, a honeycomb core 3 as a rectifying grid, and a blade 1.
3 is comprised. As shown in FIG. 1, air is blown out, and air 41 having a predetermined flow rate is continuously supplied to the blowout grill 1 from a duct (not shown).

[0006] A perforated plate or a punching plate 2 (hereinafter referred to as
It is called a perforated plate 2. In FIG. 1), as shown in FIGS. 1B and 2A, a plurality of holes 21 having a diameter d are regularly formed at a hole pitch p. Air from the duct is supplied into the blowout grill 1 through the holes 21 of the perforated plate 2.
From this hole 21, air 41 is jetted into the blow grill 1 at high speed, and as shown by broken lines in FIGS. 1A and 2A, a plurality of jets 42 (jets) having a circular cross section are formed. It spreads at a constant spread angle A (see FIG. 2A).

The honeycomb core 3 is disposed inside the housing 12 and downstream of the perforated plate 2 in the ejection direction 43 at a certain distance from the perforated plate 2. 42 are provided over the entire surface of the passage (see FIG. 1A). And a small hole 31 of regular hexagon
2 (see FIG. 2A), and the hole 31 is directed in the ejection direction 43. The honeycomb core 3 straightens the jet 42 by the holes 31. The opposite side b of the hole 31
Is smaller than the diameter dj of the jet 42.

[0008] The jet 42 is ejected from the perforated plate 2 while entraining the air in the surrounding space outside the outlet grill 1 in the ejection direction 4.
3 and reaches the honeycomb core 3, communicates with some of the holes 31, and further ejects in the ejection direction 43 (FIG. 1).
(A)). The flow of the entrained air is
This is a secondary flow called (or entrained flow). While the flow velocity of the jet 42 decreases as it goes downstream, the jet 42 mixes with the accompanying flow 44, so that the flow rate of the jet 42 increases. The accompanying flow 44 passes through several holes 31 in the honeycomb core 3 corresponding to the region 32 through which the jet 42 does not pass (see FIG. 2B) in the direction opposite to the ejection direction 43, and the perforated plate 2 And the honeycomb core 3 are supplied to the space 45.

Since the flow rate of the accompanying flow 44 is proportional to the diameter dj of the jet 42 at the upstream end face 33 of the honeycomb core 3, the jet 42 from the perforated plate 2 must be adjusted so that the accompanying flow 44 has the maximum flow rate. It is better to develop as much as possible. However, on the other hand, if the adjacent jets 42 interfere with each other, the accompanying flow 44 is restricted. Therefore, the ejection direction 4 is larger than the position where the jets 42 interfere with each other.
By disposing the honeycomb core 3 on the upstream side of the honeycomb 3, interference between the jets 42 can be prevented. The position at which the jets 42 interfere with each other is based on the generally known jet 42.
Can be easily predicted from the spread angle A of. As described above, in addition to the entrainment after the blowing (the circulating air 107 in FIG. 6) used in the related art, the net blowing air volume can be increased by the flow rate of the accompanying flow 44. That is, the hydrodynamic characteristics of the jet 42 are used to increase the amount of blown air.

[0010] Between the perforated plate 2 and the honeycomb core 3 (space 4
5) is separated by the interval dimension L. The flow rate of the accompanying flow 44 has a correlation with the interval dimension L. The case where the flow rate of the accompanying flow 44 is optimally designed to be maximum will be described below. That is, the interval dimension L is a value calculated by L = (pd) / (2 · tan A) (1). Here, d is the hole 21 of the perforated plate 2
, P is the hole pitch of the holes 21 of the perforated plate 2, and A is the spread angle of the jet 42 (see FIG. 2). The spread angle A is
It can be determined in advance. In the present embodiment, 10
Degrees to about 15 degrees. The process of deriving Equation (1) will be described. Jet 4 at upstream end face 33 of honeycomb core 3
2 is dj = d + 2 · L · tan A (2). When the diameter dj is equal to the hole pitch p of the perforated plate 2, the flow rate of the accompanying flow 44 becomes maximum. Therefore, d + 2 · L · tan A = p (3). When this equation (3) is solved for the spacing dimension L, the following equation is obtained.
Obtain (1).

The distance L between the porous plate 2 and the honeycomb core 3
FIG. 3 shows the results of an actual experiment on the correlation between the flow rate and the flow rate. In the graph of FIG. 3, the vertical axis represents the flow rate as a relative value, and the horizontal axis represents the interval L in units of mm. Each flow rate was measured when the interval dimension L was set to each value of 26.1 mm (circled in the figure), 31.8 mm (regular triangle in the figure) and 35.7 mm (square in the figure), and the results were plotted on a graph. When connected, the result is as shown in the figure. Comparing the case where the value of the interval dimension L is reduced and the case where the value is increased from the position where the flow rate is maximized, when the flow rate decreases, the latter rate is larger due to interference between the jets 42. . The diameter d of the hole 21 of the perforated plate 2 is 8.6 m.
m, the hole pitch p is 23.3 mm, and the flow rate was measured 50 mm from the downstream end face 34 of the honeycomb core 3 (see FIG. 1A).
Only at a distance. According to equation (1),
When the spread angle A = 12.5 degrees, L = (23.3−8.6) / (2 · tan12.5) (4) = 33.2 mm (5) It was expected to be the maximum, and in fact, similar results could be obtained with the graph of FIG. However, since the divergence angle A of the jet 42 depends on the finishing of the holes 21 of the perforated plate 2, the Reynolds number, and the like,
It is desirable to make a rough check in Equation (1) and confirm it experimentally.

By setting the distance L to the value given by the equation (1), the honeycomb core 3 can be installed at a position where the adjacent jets 42 do not interfere with each other. And
In the space 45 sandwiched between the perforated plate 2 and the honeycomb core 3, the flow rate of the jet 42 can be maximized, and an optimal design can be performed. In addition, the blowing direction can be appropriately adjusted by the blade 13. Further, when the perforated plate 2 or the honeycomb core 3 is movable along the ejection direction 43 and the interval dimension L is variable, the amount of blown air can be adjusted by utilizing the suppression of the accompanying flow 44 due to the interference between the jets 42. Is also applicable.

Next, a second embodiment is shown in FIG. Second
This embodiment is an application of the principle of the first embodiment, and FIG. 4 shows a part of a blow-out grill 5 for air conditioning in cross section. The blowout grill 5 has the first basic configuration.
This is almost the same as that of the first embodiment, and comprises a housing 51, a perforated plate 6, and a blade 52. In the second embodiment, no honeycomb core is provided. As in the first embodiment, a perforated plate or a punching plate 6
From a hole 61 (first hole) of the perforated plate 6 (hereinafter, referred to as a perforated plate 6), air 71 is jetted at a high speed into the blowout grill 1, and as shown by broken lines in FIG. It spreads at a constant spread angle A. A hole 53 (second hole) is formed around the side surface portion of the housing 51 downstream of the perforated plate 6, and the accompanying flow 74 is taken in through the hole 53. Therefore, the accompanying flow 74 is mixed with the jet 72, and the amount of the blown air can be increased by the flow rate of the accompanying flow 74. In the present embodiment, the holes 53 are provided on the four sides. In addition, the holes 53 are provided to be inclined in the ejection direction 73 so that the jets 72 and the accompanying flows 74 can be smoothly mixed.

[0014]

According to the present invention, in addition to entrainment of the circulating air in the air-conditioning area after the air is blown out, the circulating flow in the air-conditioning area is increased before the air is blown out by the accompanying flow in the blow-out grill. Thus, the net blowing air volume can be increased.

[Brief description of the drawings]

FIG. 1 is a view showing a first embodiment of an air-conditioning outlet grill according to the present invention, wherein FIG. 1 (a) is a cross-sectional view and FIG. 1 (b) is an end view on the suction side.

FIGS. 2A and 2B are partially enlarged views of FIG. 1, in which FIG. 2A is a sectional view, and FIG. 2B is an end view on the suction side.

FIG. 3 is a graph showing a result of an actual experiment of a correlation between a gap size between a perforated plate and a honeycomb core and a flow rate;
The vertical axis is the flow rate, and the horizontal axis is the interval size.

FIG. 4 is a view showing a second embodiment of an air-conditioning outlet grill according to the present invention.

FIG. 5 is a cross-sectional view illustrating a conventional air-conditioning outlet grill.

FIG. 6 is a diagram showing the flow of blown air and the entrainment of circulating air.

[Explanation of symbols]

 1, 5 blow-off grill 2, 6 perforated plate 3 honeycomb core 11 suction side 12, 51 case 13, 52 blade 21, 31, 53, 61 hole 32 area 33 upstream end face 34 downstream end face 41, 71 air 42, 72 jet 43 , 73 Jetting direction 44, 74 Associated flow 45 Space A Spread angle b Opposite side d, dj Diameter L Interval dimension p Hole pitch

Claims (2)

[Claims] 1. A perforated plate in which a plurality of holes having a diameter d are formed at a hole pitch p, and a rectifying grid arranged downstream of the perforated plate, wherein a fluid flow ejected from the holes spreads at a spreading angle A. Sometimes, the distance L between the perforated plate and the rectifying grid is L ≦ (p
(D) / (2 · tan A). 2. A perforated plate having a plurality of first holes formed therein, and a second hole for taking in air around a fluid flow ejected from the first holes is formed downstream of the perforated plate. An air-conditioning outlet grille characterized by being made.