JPS613933A - Controlling system of air conditioning of special working room - Google Patents

Abstract

PURPOSE:To prevent the deterioration of control performance by a method wherein a pressure difference between ambient pressures is compared by a door between high-pressure chamber and low-pressure chamber to control the rotating speed of an exhaust fan and the opening or closing if a damper, in the control of air conditioning of a super LSI manufacturing chamber or the like. CONSTITUTION:When a door 14 is opened, the computer 13 received the opening signal, both of clean rooms 1, 1' are handled as an integral room, the pressure difference between an indoor pressure and the ambient pressure is compared with the allowable value, and the value, and the rotating speed of an air supplying fan 7 is increased to make the pressure difference same as the allowable value in case the pressure difference is lower than the allowable value. On the other hand, when the pressure difference is within the allowable value, the follow-up property of the damper 5 for the high-pressure chamber 1 is increased while the same property of the damper 5' for the low-pressure chamber 1' is reduced by the control of the opening and closing of the dampers 5, 5'. According to this constitution, the fluctuation of chamber pressures may be restrained into minimum, restoring time may be shortened and the deterioration of control performance may be prevented evenif through pass is generated by the opening and closing of the door.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to air conditioning control of so-called clean rooms where special operations such as ultra-LSI manufacturing, precision machinery assembly, or biotechnology experiments involving unknown microorganisms are performed. Regarding the method.

[Prior art and its problems]

In order to prevent dust from entering from the outside world and maintain an ultra-clean environment, it is necessary to maintain positive pressure indoors, and to prevent bacteria and harmful substances from leaking to the outside world, it is necessary to maintain negative pressure indoors. need to be controlled.

In response to these demands, a control method has been proposed that maintains a constant air volume and room pressure indoors, and uses variable air volume operation of the fan to save power for fans in air supply and exhaust spaces. A conventional example of such a system will be explained, thereby clarifying the object of the present invention.

Figure 3 is a block diagram showing a conventional example.
1' is equipped with a circulation duct 3゜3' having circulation fans 2, 2'' to maintain the desired pressure inside the room, respectively.
An ultra-high performance filter (
A HEPA filter) 4.4' is installed.
- An air supply duct 6 provided with a damper 5°5' is connected to the circulation fans 2 and 2', and an air supply fan 7 is provided on the inflow side of the air supply duct 6. Depending on the detection result of the installed differential pressure gauge 8.8', the controller 9
, 9 degrees, the dampers 5 and 5' are controlled to open and close.

Further, a plurality of draft chambers 10, 10' are placed in the chrysorooms 1 and 11, and the draft chambers 10 and 10'
, an exhaust fan 1 is connected to the exhaust duct 11 connected to the
2 is provided.

In the figure, reference numeral 13 denotes a control microcomputer. The computer 13 receives output from the draft chamber 10.degree. 10', detects the number of devices in use, and controls the rotational speed of the exhaust fan 12 based on the detection result. If fluctuations occur in the clean room 1, 1', use a differential pressure gauge 8.8.
' detects this and the dampers 5, 5 are activated by the controllers 9, 9''.
゛Control opening and closing. By the way, if the desired pressure cannot be obtained even if the dampers 5, 5'' are fully opened, the dampers 5, 5''
' inputs a full open signal to the computer 13 via a limit switch (not shown) provided therein, and the computer 13 receives this full open signal and controls the air supply fan 7 to increase its rotational speed. .

By performing the two-step control of opening/closing the dampers 5 and 5' and controlling the rotation speed of the air supply fan 7 in this way, fine-grained control can be carried out, and the rotation speed of the air supply fan 7 can be controlled inadvertently. This makes it possible to realize power-saving operation without increasing the (For the above constant air volume constant room pressure control system, see the June 1983 issue of the magazine "Kinsou") By the way, the clean room 1.1' is configured such that 1 is a high pressure room and 1 is a low pressure room. If they are connected to each other through a door 14, when the door 14 is opened, air flows from room 1 to room 1', a so-called through path, and the constant air volume and stationary air flow set for each room occur. This results in a value that deviates significantly from the target value of pressure control. Further, even if the door 14 is closed, it takes a long time to restore the door to its original state.

[Purpose of the invention]

The purpose of the present invention is to eliminate the disadvantages of the conventional example, to minimize fluctuations caused by the formation of through paths between rooms, and to enable recovery in a short time after the through path is lost. An object of the present invention is to provide an air conditioning control method for a special work room that can prevent a decline in control performance.

[Key points of the invention]

However, according to the present invention, the purpose of the lever is to detect the number of draft chambers in use and have the computer control the rotation speed of the exhaust fan, and to detect room pressure fluctuations to open and close the damper and control the rotation speed of the supply air fan. In a constant air volume constant room pressure control system that performs two-stage air supply control, the damper can be opened and closed by a computer, and an open/close detector is installed on the door between the consecutive high-pressure chambers and low-pressure chambers. If the open signal is received, the combiator determines whether the differential pressure with the surroundings is within the allowable value, and if it is below the allowable value, increases the rotation speed of the air supply fan; For example, this can be achieved by increasing the followability of the damper in the high pressure chamber and reducing the followability of the damper in the low pressure chamber.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart, and FIG.
Figures and illustrations - Components have been given the same reference numerals.

That is, the draft chambers 10.10' in the clean room 1.11 of the high-pressure room and the low-pressure room send drive signals to the microcomputer 13. Upon receiving this signal, the computer 13 determines the number of draft chambers 10.10' to be used. The rotation speed of the exhaust fan 12 is controlled accordingly. In the present invention, the differential pressure gauges 8, 8 disposed within the room 1.1°
' is introduced into the computer 13, an opening/closing control signal from the computer 13 is introduced into the dampers 5, 5' provided on the inflow side to the circulation fan 2.2', and the computer 13 controls the dampers 5, 51. Controlled opening/closing. As a result, the adjustment needle 9.9° (
(see Fig. 3) is no longer required, and the opening/closing state of the dampers 5, 5' is determined by the opening/closing control signal (see Fig. 3) generated by the computer 13 itself.
Since the detection can be made by directly converting the digital value) into the damper opening degree, limit switches and wiring provided on the dampers 5 and 51 can be omitted.

On the other hand, it is the same as before that the rotation speed is controlled by the computer 13 by giving a rotation control signal to the air supply fan, and the computer 13 can simultaneously detect the air volume of the air supply fan 7 by issuing this rotation control signal. become.

In this way, the dampers 5 and 5' are opened and closed, and the air supply hood 7 is opened and closed.
Two-stage control is performed, and the high-pressure room clean room 1 and the low-pressure room clean room 11 are connected to
An open/close detector 15 using a limit switch is provided in the fl14, and the output signal of the open/close detector 15 is sent to the computer 13.
I decided to introduce it to .

("°1゛""ゞ"゛゛゛""6""""'''The door open signal is input to the computer 13 (step), and the computer 13 stops executing the control program that has been running so far. Then, treat both clean rooms 1 and 11 as one unit and determine whether the differential pressure between the room and the surroundings is within or below the allowable value.If it is below the allowable value, turn on the air supply fan. 7 to ensure the necessary differential pressure with respect to the surroundings (Step C).

In addition, if it is within the allowable value, chrysoroom 1, which is a hyperbaric chamber,
The followability of the damper 5 on the side is improved, and the followability of the damper 51 on the 1° side of the chrysoroom, which is a low pressure chamber, is decreased (Step 2). Note that improving followability means increasing the proportionality constant of the damper, that is, increasing the operating sensitivity.

When the door 14 opens, a through path is formed and the clean room 1
The damper 5 opens as the pressure decreases, and the amount of air flowing into the room 1 is accordingly increased to ensure air flow from the room 1 to the room 1', that is, from the high pressure chamber to the low pressure chamber. On the other hand, in the clean room 11 as a low-pressure room, the damper 5' tried to close, but the pressure increases when the damper 5'' is close to being fully closed, so this damper 5'
There is no need to close 1. Rather, consideration was given to reducing the followability as described above so as to improve the recovery speed after the door 14 is closed and there is no through path.

By the way, when the door 14 is closed, the opening/closing detector 15
The computer 13 determines whether the door 14 has been open until now based on the time when the door open signal is sent from the computer 13 (Snapshot). Then, immediately after the door 14 is closed, the followability of the dampers 5, 5° is improved in order to further speed up the recovery after the through path disappears (go to step). Also,
If the door 14 has been open/closed for a long time, the opening degree of the dampers 5, 5' is controlled so as to perform normal constant volume constant room pressure control (step).

〔Effect of the invention〕

As described above, in the air conditioning control system for a special work room of the present invention, the computer detects the number of draft chambers in use and controls the rotation speed of the exhaust fan, and detects room pressure fluctuations to open and close the damper and air supply. In a constant volume, constant room pressure control system that performs two-stage air supply control of fan rotation speed control, even if the clean rooms are connected by doors and through-passes occur due to the opening and closing of the doors, the fluctuations caused by this can be kept to a minimum. This also makes it possible to recover quickly after the door is closed and the through path disappears, and as a result, it is possible to prevent a decline in control performance.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the air conditioning control method for a special work room of the present invention, FIG. 2 is a flowchart showing the embodiment, and FIG. 3 is a block diagram showing a conventional method. 1.1'...Clean room 2,21...Circulation fan 3.3'...Circulation duct 4.4'...Ultra high performance filter 5.5'...Damper 6...Supply air duct 7・
...Air supply fan 8,8"...Slight differential pressure gauge9.
91...Adjusting needle 10.10'...Draft chamber 11...Exhaust duct 12...Exhaust fan 13...Microcomputer 14...Door 15...Opening/closing detector ratio L R A construction , company i

Claims (1)

[Claims] The computer detects the number of draft chambers in use and controls the rotation speed of the exhaust fan, and detects room pressure fluctuations to perform two-step air supply control: opening and closing the damper and controlling the rotation speed of the air supply fan. In the room pressure control system, the damper can be controlled to open and close by a computer, and an open/close detector is installed on the door between the consecutive high-pressure and low-pressure chambers.When a door open signal is received from the detector, the computer If the differential pressure is within the allowable value, the rotation speed of the air supply fan is increased, and if it is within the allowable value, the follow-up performance of the damper in the high pressure chamber is improved. , an air conditioning control system for special work rooms that is characterized by reducing the followability of dampers in low-pressure rooms.