JPH0648102B2 - Indoor air pressure control air conditioning ventilation equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an indoor air pressure control air conditioning ventilating facility in which the room pressure is always precisely controlled to a wide range of set room pressure even if the atmospheric pressure changes due to a meteorological phenomenon. Regarding

(Prior Art) For example, in a chamber for microfabrication using optical equipment such as semiconductor manufacturing, when the chamber pressure changes, the air density changes and the refractive index of light also changes, which is not preferable. In order to reduce the fluctuation of room pressure as much as possible, the room air pressure control air conditioning ventilation equipment is required.

As equipment for performing such atmospheric pressure control, the applicant of the present application has previously described an air conditioner for inhaling return air from a room and supplying the air to the room, an outside air passage for supplying outside air to the air conditioner, and the outside air passage. An air conditioner, an air volume adjusting damper and an outside air fan, an exhaust path for exhausting the exhaust gas of the chamber to the outside of the system, an exhaust fan and a pressure adjusting damper installed in the exhaust path. And an air flow detector in the outside air passage, and a barometer is installed in the chamber, respectively, and a control computer for inputting detection signals from the air flow detector and the barometer and the air flow of the exhaust fan and the exhaust fan A proposal has been made in which the opening of the air volume adjusting damper and the pressure adjusting damper are arithmetically controlled so that the fluctuation of the atmospheric pressure does not affect the room pressure and the room pressure is always 760 mmHg (JP-A-61). -217641 gazette).

(Problems to be solved by the invention) However, the above-mentioned proposal is made by the control computer in the start mode in the control mode (at the time of steady control) after the start mode of the air volume adjusting damper and the pressure adjusting damper. Predetermined opening with good control sensitivity (for example, approx.
50%), start the outside air fan and the exhaust fan in one of the patterns shown in Fig. 4, and set the rotation speed of the outside air fan at the output of the air volume detector so that the amount of outside air introduced becomes the predetermined air volume. When the air volume reaches a specified level, it goes into control mode independently of the exhaust fan, and the rotation speed of the exhaust fan is 760 mmHg in the room by the output of the barometer.
Until it reaches 760 mmHg, and when it detects 760 mmHg, it switches to the control mode independently of the outside air fan.In other words, the rotation speed of the outside air fan and the rotation speed of the exhaust fan are set to the same target value. With this startup mode, the chamber pressure is constantly increased to 760 mmH.
When it is set to a value lower than g, for example, it is necessary to use an exhaust fan with a torque larger than that of the outside air fan. Due to this imbalance, too much room pressure at the end of startup as shown by line A in Fig. 6 However, in the beginning of the next control mode, the rotational speed of the exhaust fan must be controlled to correct this overshoot, and there is the inconvenience that the normal control mode cannot be operated from the beginning of the control mode. It was

Further, according to the previously proposed, when the room pressure is set to a value higher or lower than 760 mmHg, the opening degree of the air flow rate adjustment damper and the pressure adjustment damper, which are butterfly valves, is set to the control sensitivity in the control mode. Good predetermined opening (about 40 ~
70% range), and set the outside air fan and exhaust fan,
When starting with each pattern of a predetermined increase rate, there is a limit to the upper limit of the frequency of the inverter unit that determines the rotation speed of the outside air fan or exhaust fan, so the rotation of the outside air fan or exhaust fan corresponding to the set room pressure It cannot be increased to a certain number, and in order to compensate for it, the opening of the air volume adjusting damper or the pressure adjusting damper is controlled to be larger than the predetermined opening. Therefore, when the start mode is changed to the control mode, the opening positions of the air volume adjusting damper and the pressure adjusting damper are set to positions outside the positions with good control sensitivity. Therefore, in the control mode, there is an inconvenience that these dampers cannot precisely control the chamber pressure to a set value higher or lower than 760 mmHg.

(Means for Solving the Problems) The present invention is intended to provide equipment capable of smoothly shifting from the operation in the start mode to the normal operation in the control mode and capable of controlling the set room pressure in a wide range in the control mode. An air conditioner that inhales the return air of the room and supplies the air to the room,
An outside air passage for supplying outside air to the air conditioner, an outside air conditioner interposed in the outside air passage, an air volume adjusting damper and an outside air fan, and an exhaust passage for discharging the exhaust air of the chamber to the outside of the system, An exhaust fan and a pressure adjusting damper provided in the exhaust passage are provided, an air flow detector is installed in the outside air passage, and a barometer is installed in the chamber, respectively, and detection signals from the air flow detector and the barometer are provided. In the indoor air pressure control air-conditioning ventilation equipment, the air volume of the outside air fan and the exhaust fan and the opening degree of the air volume adjusting damper and the pressure adjusting damper are arithmetically controlled by an input control computer. Each of them is equipped with a volume damper, and at the time of startup, the openings of the pressure adjusting damper and the air volume adjusting damper are set to predetermined opening with good control sensitivity, and the opening of the volume damper is set to the measurement chamber at the time of starting. Pressure and set room pressure The opening is set according to the difference, and the air volume of the exhaust fan or the outside air fan is controlled to increase according to the deviation between the measurement chamber pressure and the set chamber pressure, and during steady control, the opening of the air volume adjustment damper is set. Controlling the opening degree of the pressure adjusting damper from the predetermined opening degree so that the outside air flow rate always becomes a predetermined blowing rate, and controlling the opening degree of the pressure adjusting damper from the predetermined opening degree so that the room pressure becomes a predetermined room pressure. It is characterized by doing so.

(Operation) The present invention has the above-described configuration. According to this, in the start-up mode, as in the previously proposed facility, the air flow rate adjustment damper and the pressure adjustment damper have a predetermined opening degree with good control sensitivity. For example, in the case of a negative pressure chamber, when the external air fan is operated in the pattern shown in FIG. 5, both volume dampers are initially activated by the control computer that inputs the detection signal from the air flow detector and the barometer. Is set to an opening degree according to the deviation between the measured chamber pressure and the set chamber pressure, and the exhaust fan is set to a rotational speed according to the deviation between the measured chamber pressure and the set chamber pressure for each sampling time as shown in FIG. 5, for example. Controlled.

Since the opening of both volume dampers is controlled to the opening according to the deviation between the measured chamber pressure and the set chamber pressure at the time of starting as described above, the opening of the air volume adjusting damper and the pressure adjusting damper in the starting mode. However, the set chamber pressure can be set only by controlling the rotation of the exhaust fan while maintaining a predetermined opening with good control sensitivity. Therefore, in the control mode, the air volume adjusting damper can control the outside air volume to a predetermined air volume, and the pressure adjusting damper can precisely control the set room pressure over a wide range.

Further, since the exhaust fan is controlled to the number of revolutions according to the deviation between the measured chamber pressure and the set chamber pressure, there is almost no overshoot of the chamber pressure at the end of startup as shown by line B in FIG. The pressure can be set, and the control mode can be smoothly shifted to the next control mode.

For example, in the case of a positive pressure chamber, contrary to the case of a negative pressure chamber, the air volume of the exhaust fan is operated in the pattern shown in FIG. 5, and the air volume of the outside air fan is measured until it reaches a predetermined air volume. Increase according to the deviation between the room pressure and the set room pressure.

(Example) Next, the Example of this invention is described based on drawing.

In FIG. 1, (1) shows a chamber that requires indoor air pressure control for performing microfabrication using optical equipment.
A suction port (2), an air supply port (3) and an exhaust port (4) are provided in the.

The suction port (2) is connected to the air conditioner (6) through the ventilation duct (5), and the air supply conditioned by the air conditioner (6) is supplied through the air supply duct (7). It is blown into the chamber (1) from (3).

The exhaust port (4) is connected to an exhaust duct (9) which is an exhaust passage in which an exhaust fan (8) is interposed, and the exhaust gas in the chamber (1) is driven by the exhaust fan (8) to form the exhaust duct. It is discharged to the outside of the system via (9).

The air conditioner (6) is connected to an outside air duct (12) that is an outside air passage in which an outside air conditioner (10) and an outside air fan (11) are interposed, and the outside air is set by the outside air conditioner (10). The outside air fan (1
The air conditioner (6) is driven through the outside air duct (12) by driving 1).
Sent to.

In the exhaust duct (9), a pressure adjusting damper (13) is further provided upstream of the exhaust fan (8), and in the outside air duct (12), the air volume is further adjusted downstream of the outside air fan (11). Damper (14)
Is installed.

The air volume in the outside air duct (12) is detected by an air volume detector (15) installed therein, and the air pressure in the chamber (1) is detected by a barometer (16) installed therein.

As the exhaust fan (8) and the outside air fan (11) shown in the figure, a variable air volume control fan is used.
(8) The variable air volume control of (11) is performed by the inverter units (17) and (18) that can freely control the rotation speed of the fan motor.

Detection signals from the air flow detector (15) and the barometer (16) are input to the control computer (19), and the control computer
The input value is calculated from (19) and the opening control signals of the pressure adjusting damper (13) and the air flow adjusting damper (14) and the control signals to the inverter units (17) and (18) are put in other words, the exhaust fan.
The air volume control signals of (8) and the outside air fan (11) are output.

Although the above-mentioned configuration is not particularly different from the previously proposed facility, in the present invention, the volume dampers (20) (21) are provided in the outside air duct (12) serving as the outside air passage and the exhaust duct (9) serving as the exhaust passage, respectively.
The control computer (19) adjusts the opening of both volume dampers (20) and (21) to the opening according to the deviation between the measured room pressure and the set room pressure at the time of startup when the air conditioning ventilation equipment is started. The air volume of the exhaust fan (8) is arithmetically controlled to the air volume corresponding to the deviation between the measured chamber pressure and the set chamber pressure.

The start-up mode and control mode by the control computer (19) will be described below.

[Starting Mode] For example, when the control computer (19) is operated after the initial opening of the air volume adjustment damper (14) and the pressure adjustment damper (13) is set to 60%, the control computer (19) Immediately the barometer
The opening of both volume dampers (20) and (21) is determined by calculating the deviation between the measured chamber pressure and the set chamber pressure at the time of startup detected by (16). For example, when the measurement chamber pressure is 1013 mb and the set chamber pressure is 993 mb, the opening of the volume damper (20) is set to 40% by the opening control signal from the control computer (19),
The opening of the volume damper (21) is set to 60%.

When the rotation speed of both fans (8) and (11) is raised in this state, the room pressure gradually decreases. Starting both fans (8) and (11) gradually increases the output frequency of the inverter units (17) and (18) by the control computer (19) and increases the rotation speed, and asymptotically without overshooting the set target value. Adopt bumpless start. Explaining this in more detail, the outside air fan (11) linearly increases the number of revolutions up to the set air volume in the same manner as the previously proposed one, and the exhaust fan (8)
For example, the number of revolutions is increased every one second so that the air volume corresponds to the deviation between the measured chamber pressure detected by the barometer (16) and the set chamber pressure. That is, when the deviation is large, the exhaust fan
The rate of increase of the number of rotations in (8) is increased, and conversely, when the deviation is small, the number of rotations is increased in a curvilinear manner so as to reduce the rate of increase of the number of rotations. By such a correction operation of the exhaust fan (8), the overshooting amount of the room pressure at the end of startup is reduced as much as possible, and a smooth transition to the next control mode is possible.

FIG. 2 is a flowchart in the starting mode of this embodiment.

First, the measurement chamber pressure Pls at the time of startup measured by the barometer (16)
Computer (19) for controlling the deviation εs between the pressure and the set room pressure Po
Is calculated (step S1), the opening signal of the volume dampers (20), (21) corresponding to this deviation is output from the computer (19) (step S2), and the opening is controlled. After calculating the deviation ε between the measured chamber pressure Pl and the set chamber pressure Po in step S3, the rotation speed Zsf of the outside air fan (11) is calculated in step S4 as Zsf = Zsfo · Qsfo · (t / T1) where T1: set air volume Arrival time setting time, Qsfo:
It is calculated from the equations of set air volume, Zsfo: proportional constant, t: elapsed time (step S4), and a signal corresponding to the rotational speed Zsf is supplied to the inverter unit (18) (step S5). In step S6, the rotation speed Zef of the exhaust fan (8)
Zef = Zefo [Qsfo (t / T1) + As.ε] where Zefo: proportional constant As: parameter that governs control sensitivity is calculated from the equation of the rotational speed Zef and the signal corresponding to the rotational speed Zef is calculated by the inverter unit (17). (Step S7).

In step S8, the air volume of the outside air fan (11) is set to the set air volume Qsf.
It is judged whether or not o has occurred, and if not, the process returns to step S3 again. When the set air volume is reached, the start-up mode ends, so the process moves to the next control mode.

In the negative pressure chamber as in the above embodiment, the rotation speed of the exhaust fan (8) is controlled as a curved gradient, and the rotation speed of the outside air fan (11) is controlled as a linear gradient. (11)
, It is necessary to use a motor with a torque greater than that of the exhaust fan (8) to increase the rotation speed of the exhaust fan (8) at the end of the startup mode, so that the normal control mode operation is performed from the beginning of the control mode. For exhaust fan (8)
The rotational speed of is controlled as a linear gradient, and the rotational speed of the outside air fan (11) is controlled as a curved gradient.

[Control mode] Outside air volume detected by the air volume detector (15) and barometer (16)
By taking in the measurement chamber pressure detected by the control computer (19), the control computer (19) controls the opening of the air volume adjusting damper (14) so that the outside air volume is always a predetermined air volume, and Independent of outside air volume, room pressure is always
The opening of the pressure adjusting damper (13) is controlled so as to be 993 mb.

Incidentally, the control signals, that is, the control states of the air volume adjusting damper MD1 (14), the pressure adjusting damper MD2 (13), the volume damper VD1 (20) and the volume damper VD2 (21) in each mode are as shown in FIG. .

If there is a forced local exhaust facility in the room (1) due to handling harmful substances, etc., the operating number of this facility is monitored by scanning, and the exhaust air volume is controlled by the control computer (19). The static pressure corresponding to the exhaust air volume is calculated, and the exhaust fan (8) is calculated from this air volume and static pressure.
After calculating the rotation speed of the inverter unit (17) (18)
The control signal may be sent to the.

(Effects of the Invention) As described above, according to the present invention, there is almost no overpressure of the chamber pressure at the end of startup, and the control mode can be smoothly shifted to the next control mode. It has the effect of controlling the pressure in a wide range.

[Brief description of drawings]

FIG. 1 is a device arrangement system diagram showing an example of the embodiment of the present invention, FIG. 2 is a flow chart in the starting mode of the embodiment of FIG. 1, FIG. 3 is a control characteristic diagram of the embodiment of FIG. FIG. 4 is a diagram showing an example of the starting patterns of the outside air fan and the exhaust fan of the previously proposed equipment, FIG. 5 is a diagram showing an example of the starting patterns of the outside air fan and the exhaust fan of the present invention, and FIG. It is a figure which shows the control state of the room pressure of the proposed equipment and the equipment of this invention. (1) …… Room (6) …… Air conditioner (8) …… Exhaust fan (9) …… Exhaust duct (exhaust path) (10) …… Outdoor air conditioner (11) …… Outside air fan (12)… … Outside air duct (outside air passage) (13) …… Pressure adjusting damper (14) …… Air volume adjusting damper (15) …… Air volume detector (16) …… Barometer (19) …… Control computer (20) ) (21) …… Volume damper

Claims (1)

[Claims] 1. An air conditioner (6) for inhaling return air from a room (1) and supplying the same to the room (1), and an outside air passage (12) for sending outside air to the air conditioner (6).
An external air conditioner (10), an air volume adjusting damper (14) and an external air fan (11) installed in the external air passage (12), and an exhaust air for exhausting the exhaust gas from the chamber (1) to the outside of the system. An exhaust passage (9), an exhaust fan (8) interposed in the exhaust passage (9) and a pressure adjusting damper (13), and an air flow detector (15) in the outside air passage (12), A barometer (16) is installed in each of the chambers (1), and the air flow detector (15) and the barometer (16) are installed.
A control computer (19) for inputting a detection signal from the computer calculates the air volume of the outside air fan (11) and the exhaust fan (8) and the opening degree of the air volume control damper (14) and the pressure control damper (13). In the indoor air pressure control air conditioning ventilation equipment that is controlled, volume dampers (20) and (21) are provided in the outside air passage (12) and the exhaust passage (9) respectively, and at the time of startup, a pressure adjusting damper (13) Also, the opening of the air volume adjusting damper (14) is set to a predetermined opening with good control sensitivity, and the volume damper is
Set the opening of (20) and (21) to the opening according to the deviation between the measured chamber pressure and the set chamber pressure at the time of startup, and then set the exhaust fan (8)
The air volume of (11) is controlled so as to increase according to the deviation between the measurement chamber pressure and the set room pressure, and during steady control, the opening of the air volume adjustment damper (14) is set so that the outside air air volume is always the predetermined air volume. Control from the predetermined opening so that the pressure adjustment damper (1
An indoor air pressure control air conditioning / ventilation facility characterized in that the opening degree of 3) is controlled from the predetermined opening degree so that the room pressure becomes a predetermined room pressure.