JPH01142354A - Ceiling blow-off structure for air-conditioning room - Google Patents

Abstract

PURPOSE:To uniformize air speed distribution in a room by a method wherein a plurality of perforated plates are provided on a the air blow-off surface of the ceiling of an air-conditioning room to provide air with main blow-off surface resistance and provided the dynamic pressure of airflow, blown into a ceiling chamber, with a proper resistance at the blow-off surface of the ceiling. CONSTITUTION:A perforated plate 11, having a small opening rate, is provided with openings 11a with a hole pitch P1. Another perforated plate 12 is provided with openings 12a with a pitch P2 smaller than the hole pitch P1 of the perforated plate 11. The perforated plates 11, 12 constitute a double-plate ceiling so as to keep an interval (l) capable of diffusing the airflow of blow-off air. Accordingly, the dynamic pressure of the airflow, blown into the ceiling chamber 10 by an air conditioner 3 through ducts 8, 9, is provided with main blow-off surface resistance by the plurality of perforated plates 11, 12 having small opening rates; then, the air flows into the area of space between the perforated plates 11, 12 and the airflow is diffused. The diffused airflow is blown off into the room 1 from the whole surface of the ceiling with an uniform air speed distribution; therefore, air is conditioned without any unevenness and the post-conditioning air is sucked into a floor chamber 14 through the opening of a floor 13.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a ceiling blowout structure for an air conditioned room, and particularly to a ceiling blowout structure for an air conditioned room suitable for uniformizing the wind speed distribution on the indoor side of the air conditioned room. It's about structure.

[Conventional technology]

First, a conventional general air conditioning system having a ceiling-wide outlet structure will be explained with reference to FIG.

FIG. 2 is a schematic configuration diagram showing, as an example, an air conditioning system for a conventional constant temperature room having a floor suction structure.

In FIG. 2, reference numeral 1 indicates a constant temperature room for the air-conditioned room, 2 a chiller unit, 3 an air conditioner, a cooler 4, a heater 5. It is equipped with a blower 6. Reference numeral 7 denotes a cold water pipe connecting the chiller unit 2 and the cooler 4, and these air conditioning equipment such as the air conditioner 3 and the chiller unit 2 are placed outside.

8 is a ventilation duct that sends conditioned air blown by the blower 6 into the ceiling chamber 10; 9 is a floor chamber 14;
This is a blower duct that connects the air conditioner 3 and the air conditioner 3.

The ceiling of the constant temperature room 1 is separated from the ceiling chamber 10 by a perforated plate 15, and has a ceiling-wide blowout structure in which conditioned air is blown out from the openings of the perforated plate 15. Further, the floor 13 of the constant temperature room 1 has a large number of openings for sucking conditioned air into the floor chamber 14.

In the equipment shown in Fig. 2, the dynamic pressure of the air flow blown into the ceiling chamber 10 as shown by the arrow is the main cause of uneven air velocity distribution toward the indoor side, so there is resistance inside the ceiling chamber 10. It was necessary to take measures such as installing additional members or increasing the height of the ceiling chamber 10 sufficiently. However, in reality, it is difficult to increase the height of the ceiling chamber due to limited equipment space, and it is not easy to obtain a highly accurate distribution of the wind speed blown into the constant temperature room 1.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, when providing sufficient resistance to the air outlet surface of the ceiling of the thermostatic chamber 1 shown in FIG. In order to obtain sufficient resistance, a material with a fairly small aperture ratio is required. In other words, a material with a considerably small ratio of hole diameter to hole pitch is required.

However, reducing the hole diameter of a perforated plate requires processing technology,
There is a limit in terms of processing cost, and it is also quite conceivable that maintenance efforts will increase due to clogging due to dust. The same problem of clogging due to dust occurs when a filter material such as fibrous material is used as the resistance member, for example.

Furthermore, increasing the pitch of the holes in the perforated plate was not effective because it increased the variation in wind speed directly below the blowing surface.

The present invention has been made in order to solve the problems of the prior art described above, and can provide an appropriate resistance to the dynamic pressure of the air flow blown into the ceiling chamber at the ceiling blowing surface, thereby making it possible to equalize the indoor wind speed distribution. The purpose is to provide a ceiling blowout structure for an air conditioned room.

[Means for solving problems]

In order to achieve the above object, the configuration of the ceiling blowing structure for an air conditioned room according to the present invention includes at least an air conditioning device and a ventilation duct outside the air conditioned room, and blows air into the room from the ceiling of the air conditioned room to the floor or In a device that circulates conditioned air by sucking air from near the floor, the air blowing surface of the ceiling is formed by a first porous plate with a small aperture ratio that provides the main blowing surface resistance, and the first porous plate and the opening. It is composed of a plurality of perforated plates with the same or larger aperture ratio, and a perforated plate on the indoor side with a larger aperture ratio than those perforated plates.

More specifically, the plurality of perforated plates are arranged at intervals that allow the air flow of the blown air to be diffused.

It should be noted that the present invention is characterized in that the resistance capable of making the wind speed distribution in the room uniform is obtained by providing multiple perforated plates at appropriate intervals.

[Effect]

The dynamic pressure of the air flow blown into the ceiling chamber from the outdoor air conditioner through the air duct is mainly given resistance by the multiple perforated plates with small opening ratios, and Inflow.

That airflow is diffused. The diffused air flow finally passes through a perforated plate on the indoor side with a large aperture ratio and a small hole pitch, and is blown into the room from the entire surface of the ceiling with a uniform wind speed distribution. Therefore, indoor air conditioning is performed evenly,
The conditioned air is sucked into the floor chamber through the opening in the floor, returns to the outdoor air conditioning equipment, and is then circulated.

This allows the constant temperature room to maintain the required temperature and cleanliness.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIG. 1 and FIGS. 3-4.

Fig. 1 is a schematic configuration diagram showing the air conditioning equipment of a constant temperature room having a ceiling blowing structure according to an embodiment of the present invention, and Fig. 3 is a diagram showing the relationship between the resistance of the blowing surface and the blowing wind speed distribution. , FIG. 4 is a schematic partial view showing the double perforated plate configuration of the ceiling of FIG.

, Components in FIG. 1 with the same reference numerals as those in FIG. 2 are the same parts as in the prior art, so their explanation will be omitted.

The difference between the thermostatic chamber of this embodiment shown in FIG. 1 and the conventional thermostatic chamber shown in FIG. 2 is the structure of the ceiling that serves as the air blowing surface.
The ceiling air blowing structure of this embodiment has a double plate structure in which a first and a second perforated plate are arranged at a certain interval.

In FIGS. 1 and 4, 11 is a first porous plate with a small aperture ratio, and has openings 11a with a hole pitch PL. 12
is a second perforated plate having a larger aperture ratio than the first perforated plate 11, and this second perforated plate 12 has openings 12a with a hole pitch P2 smaller than the hole patch PI of the first perforated plate 11. There is. The first perforated plate 11 and the second perforated plate 12 constitute a double plate ceiling so as to maintain a distance that allows the air flow of the blown air to be diffused. These perforated plates are made of asbestos to suit the indoor environment or architectural conditions of the conditioned room.

Any material such as wood, metal, or plastic may be used.

The concept of setting the double-plate ceiling blowout structure shown in FIG. 4 will be explained with reference to FIG. 3 in addition to FIGS. 1 and 4.

There is an equipment-specific correlation between the resistance of the air blowing surface of the ceiling and the wind speed distribution of the blowing air flow, as shown in FIG.

In FIG. 3, the horizontal axis is the ratio (dimensionless value) of the air blowing surface resistance ΔP of the air blowing surface of the ceiling and the dynamic pressure Pv of the ceiling blowing part where air is blown from the air duct 8 to the ceiling chamber 10, and the vertical axis is The axis shows the variation δV (actually measured value) in the wind speed of conditioned air blown into the room from the ceiling, and the relationship is linear as shown by the solid line. Therefore, in order to make the blown air flow in the constant temperature room 1, which is an air-conditioned room, a desired wind speed distribution, a certain necessary resistance value may be selected. In this embodiment, the necessary blowout surface resistance is obtained using a double perforated plate shown in FIG.

The first perforated plate 11 shown in FIG. 4 is placed on the upstream side of the air flow, and is a perforated plate with a small aperture ratio that produces the main blowout surface resistance of the entire double perforated plate. The second perforated plate 12 disposed downstream has a smaller hole pitch than the first perforated plate.

The first perforated plate 11 on the upstream side and the second perforated plate 12 on the downstream side
The distance Q between the first perforated plate 11 and the first perforated plate 11 is such that the air flow blown out from the first perforated plate 11 can be sufficiently diffused.

Here, d: Hole diameter of the upstream perforated plate (diameter of opening 11a) β: Open area ratio of the upstream perforated plate
α31, June 1986, "Resistance of consecutively installed apertures and their interference" by Hisayoshi Kado and three others.

2nd report - Interference between two perforated plates''. - The above document discusses the interference between two perforated plates, but the subject is related to water flow measurement in circular pipes such as pump equipment, etc.
This system uses interference by reducing the distance between two perforated plates to provide resistance to the water flow inside the pipe without causing cavitation, and is completely different from the ceiling blowout structure of an air-conditioned room like the present invention. However, there is no disclosure of a technical idea such as making the wind velocity distribution uniform from the ceiling airflow surface.

In the present embodiment shown in FIG. 1, in order to obtain the required wind speed distribution for a constant temperature room air conditioning equipment.

ΔP > 0, requires 22 rm A q,
A resistance coefficient K>360 is required.

Note that here, the resistance coefficient is defined as shown in equation (2).

Pvc Here, ΔP: Resistance on the outlet surface Pvc: Dynamic pressure of the average wind speed on the outlet surface, and the dynamic pressure Pvc of the average wind speed on the outlet surface is defined as follows.

g Here, γ: Specific weight vc: Average wind speed on the blowing surface g: Acceleration of gravity In the example of FIG.
If the hole diameter d of a is 3 m and the hole pitch P1 is 10 m, the resistance coefficient will be K4335, and the hole diameter of the opening 12a of the second perforated plate 12 will be 3 m.

If the hole pitch Pz is 6+n+++, the resistance coefficient is K4
It becomes 35. At this time, although detailed calculations are not shown, if the distance Ω between the double plates is set to Q''55 mm from equation (1), then
Diffusion of the air flow of the blown air is possible.

With such a double perforated plate blowout surface, ΔP=0.23m
The blowout surface resistance of Aq is obtained, and the required wind speed distribution is obtained.

In the above-mentioned embodiment, an example of a constant temperature room was explained as an air-conditioned room, but this room can be widely applied to an environmental test room, a computer room, or a clean room where precision production technology is handled.

In addition, in the above numerical example, the opening of the upstream perforated plate is φ3
XP10. Although the openings of the downstream perforated plate had the same hole diameter of φ3XP6, there is no problem even if the opening hole diameters of both the perforated plates are different.

・Furthermore, in the above-mentioned embodiment, an example of a double plate configuration including a first perforated plate on the upstream side and a second perforated plate on the downstream side (indoor side) was explained, but the present invention has a double plate configuration. It is not limited to those of. Although not shown or explained, a first perforated plate with a small aperture ratio that should provide the main blowout surface resistance;
multiple perforated plates with the same or larger aperture ratio than the perforated plate,
In addition, it is also possible to adopt a multi-plate configuration of perforated plates on the indoor side that have a larger exit ratio than those perforated plates, and to maintain intervals between these multi-perforated plates so that the airflow of the blown air can be diffused. . The key point is that the multiple perforated plates on the upstream side provide the main resistance to the dynamic pressure of the air flow blown into the ceiling chamber, adjusting the turbulence of the wind speed distribution, and the air flow diffused between the multiple plates is transferred to the porous holes on the indoor side. The aperture ratio of each perforated plate may be made different so that the air can be blown into the room through the plate with a uniform velocity distribution.

〔Effect of the invention〕

As described above, the present invention provides a ceiling blowout structure for an air-conditioned room that can provide an appropriate resistance to the dynamic pressure of the air flow blown into the ceiling chamber on the ceiling blowout surface and can even out the indoor wind speed distribution. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an air conditioning system for a constant temperature room having a ceiling blowout structure according to an embodiment of the present invention. Figure 2 is a schematic configuration diagram showing the air conditioning equipment of a conventional constant temperature room;
FIG. 3 is a diagram showing the relationship between the resistance of the blowing surface and the blowing air velocity distribution, and FIG. 4 is a schematic partial diagram showing the structure of the double perforated plate of the ceiling in FIG. 1. DESCRIPTION OF SYMBOLS 1... Constant temperature room, 2... Chiller unit, 3... Air conditioner, 8.9... Air duct, 10... Ceiling chamber, 11... First perforated plate, 12... - Second perforated plate, 11a. 12a...opening, 13...floor.

Claims (1)

[Scope of Claims] 1. In a device that is equipped with at least an air conditioner and a ventilation duct outside the air-conditioned room, and circulates the conditioned air by blowing air into the room from the ceiling of the air-conditioning room and sucking air from the floor or near the floor. , the air blowing surface of the ceiling is formed by a first perforated plate with a small aperture ratio that provides the main blowing surface resistance;
A ceiling blowout structure for an air conditioned room, comprising a plurality of perforated plates having the same or larger aperture ratio than the first perforated plate, and a perforated plate on the indoor side having a larger aperture ratio than the first perforated plate. 2. A ceiling blowout structure for an air conditioned room according to claim 1, wherein the plurality of perforated plates are arranged at intervals that allow the air flow of the blown air to be diffused.