JPH10292943A - Air conditioning control method of clean room - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically perform the energy-saving operation of a clean room by operating a refrigerator at the temperature of the cooling water necessary for the operation of external and internal air conditioners to calculate the temperature of the cooling water based on the measurement result of the outside air condition. SOLUTION: When the enthalpy (i) of the outside air is compared with the enthalpy im in a clean room and im<i, the temperature of the cooling water necessary for the differential enthalpy Δi required for the dehumidifying operation of an external air conditioner is calculated. When im>=i, the temperature To of the outside air is compared with the supply air set temperature T1 from the external air conditioner, and T1<To, the temperature of the cooling water necessary for the heat exchange differential temperature ΔTo required by the external air conditioner is calculated to be A, and when T1>To, the supply air operation is performed by the external air conditioner. The temperature Ti in the clean room is compared (step 3) with the supply air set temperature T2 from the internal air conditioner, and the temperature A of the cooling water is compared (step 4) with the temperature B of the cooling water of the internal air conditioner required for the differential temperature ΔTi, and the lower temperature is the temperature condition of the coldest cooling water in the clean room.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling air conditioning in a clean room. More specifically, the present invention relates to a technology that considers outside air conditions in air conditioning control of a clean room and performs energy-saving operation of the air conditioner based on the conditions.

[0002]

2. Description of the Related Art For example, when a production environment condition has a great influence on product quality as represented by a semiconductor factory, the production equipment is placed in a so-called clean room and cut off from the external environment, so that a desired production environment is obtained. Temperature, humidity, pressure and cleanliness.

FIG. 1 shows a typical device configuration of a clean room system in a semiconductor factory. FIG.
As shown in FIG. 1, the clean room system generally purifies, humidifies, and controls the temperature of the atmosphere flowing into the clean room 10 by using the external conditioner 20 and the internal conditioner 30. That is, the heat generated in the clean room 10 partially guides the air in the clean room to the internal conditioner 30 and removes the heat by the cooler 31 in the internal conditioner. Exhaust gas generated during product manufacturing is discharged to the outside of the clean room system.
0, the dust is removed by an air filter 21 in the external controller, the purified air is once cooled by a cooler 22 and dehumidified, and the dehumidified air is heated to a desired temperature by a heater 23, Further, the air heated to the desired temperature is supplied to the humidifier 24.
Humidified to the desired humidity, sent out to the clean room side, mixed with the heat-removed air sent out from the cooler 31 of the internal conditioner, and finally into the clean room as the target temperature and humidity. I'm blowing. A high-performance filter is provided in the air blowing section 11 of the clean room to remove dust, and the internal pressure is kept constant and higher than that outside the system to ensure cleanliness.

A refrigerator 40 for controlling the cooler 22 of the external conditioner 20 and a cooler 31 of the internal conditioner 30 and a heater 23 for controlling the cooler 22 of the external conditioner 20 are provided. Boilers 50 are respectively connected.

In order to save energy in a clean room in such a semiconductor factory, for example,
JP-A-6-159751, JP-A-7-18087
As disclosed in Japanese Patent Application Publication No. 1 (1999), it has been proposed to reduce the running cost by saving space and reducing the amount of circulating air.

In Japanese Patent Application Laid-Open No. 4-327439, it is proposed that energy saving operation of an air conditioner having a heat storage tank in a general air conditioner is controlled by starting and stopping the operation of a refrigerator by applying fuzzy logic. Have been.

[0007]

However, as described above, not only is there a limit to the energy saving by reducing the space and the amount of circulating air, but there is a possibility that the production environment may be deteriorated. The method of operating the machine by controlling the start and stop of the machine with the set temperature of the machine constant does not have the problem of frequent start and stop, instead of frequent start and stop, resulting in increased energy consumption and higher cost due to the necessity of dilution operation at startup and shutdown. In fact, when operated by such a method, energy saving cannot be achieved as expected.

Accordingly, it is an object of the present invention to provide a novel clean room air conditioning control method. Another object of the present invention is to provide an air conditioning control method capable of automatically performing energy saving operation of a clean room.

[0009]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, have concluded that energy saving can be further achieved by considering outside air conditions in air conditioning control of a clean room. Have reached the present invention.

[0010] That is, the present invention for solving the above-mentioned problems,
(1) An air-conditioning control method for a clean room, in which outside air conditions are measured, a coolant temperature required for operation of an external controller and an internal controller is calculated based on the measurement result, and the refrigerator is operated at the temperature. It is characterized by doing.

In the present invention, (2) the outside air condition is measured, and the enthalpy of the outside air calculated from the result of the measurement is compared with the enthalpy of the set condition in the clean room. The present invention relates to a clean room air conditioning control method according to the above (1), which calculates a coolant temperature required for the operation of the controller and controls the operation of the refrigerator at the temperature.

Further, in the present invention, (3) measurement of the outside air condition is continuously performed, the measurement result is sequentially sent to an automatic arithmetic unit, the coolant temperature is calculated, and an operation command to the refrigerator is set to the temperature. Is performed continuously by the automatic processing device to automatically control the operation of the refrigerator. The method of controlling air conditioning of a clean room according to the above (1) or (2), is shown.

[0013]

As described above, in controlling the temperature and humidity of the clean room, first, (i) the outside air is once cooled and dehumidified by a cooler, and then (ii) the outside air is heated to a target temperature by a heater, and (iii) The operation of humidifying to the target humidity is performed in the external controller.

In the prior art, the set temperature of the refrigerator is fixed irrespective of the outside air condition. However, the enthalpy of the outside air is low during a period when the outside air temperature is low or a period when the humidity is low such as in winter. Therefore, the load on the cooler required to dehumidify to a predetermined humidity in the step (i) is reduced, and the dehumidification itself may not be necessary. Therefore, by making the operation set temperature of the refrigerator variable based on the measurement results of such outside air conditions, for example, compared to a case where the set temperature of the refrigerator is fixed and energy saving control is performed by starting and stopping the refrigerator, Furthermore, energy saving can be achieved.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail based on specific embodiments.

FIG. 2 is a block diagram showing a series of flows of operation control of the refrigerator in one embodiment of the air conditioning control method for a clean room according to the present invention.

As shown in FIG. 2, in the present invention, in the air conditioning control of the clean room, the outside air condition, that is, the outside air temperature To and the outside air humidity ho are measured by, for example, a sensor installed outside the room. Find the enthalpy i of the outside air. The enthalpy is obtained by measuring the measured temperature To and the humidity ho in a psychrometric chart as schematically shown in FIG.
Can be easily calculated by applying For example, when the temperature is A (° C.) and the humidity is a (%), the enthalpy is B (kcal / kg).
(° C) and humidity a (%) have an enthalpy of F
(Kcal / kg) (B <F), and as is well known, the higher the temperature and humidity, the higher the enthalpy. Actually, such data of the psychrometric chart is digitized and incorporated in an automatic arithmetic device such as a microcomputer, and the temperature To and the humidity h measured by the sensor are used.
The enthalpy i is automatically calculated by inputting o as an electric signal to the automatic operation device.

Next, the calculated enthalpy of outside air i
Is compared with the enthalpy im at the desired set temperature Tm and set humidity Hm in the clean room room (FIG. 2).
In the judgment step 1), according to the comparison result, judgment is divided into (a) im <i and (b) im ≧ i. The clean room set temperature Tm is, for example, 22 to 25 ° C., and the clean room set humidity is 4
It is about 0 to 50%.

Here, (a) When im <i, generally, the outside air condition is high in temperature and humidity as in summer, and cooling water for cooling the outside air with an external air conditioner to dehumidify it. The temperature is the lowest cooling water temperature condition in air conditioning. Therefore, the enthalpy difference Δi = ii required for the dehumidifying operation of the outside air conditioner.
m, and is required for this enthalpy difference Δi,
That is, the temperature of the cooling water required for dehumidifying the external conditioner is calculated.

On the other hand, when (b) im ≧ i, the outside air condition is generally low in temperature and humidity as in winter. In this case, the outside air temperature To is further blown out from the outside air conditioner to the clean room. The temperature is compared with the set temperature T1 (judgment step 2 in FIG. 2). Based on the result of the comparison, it is determined whether (b1) T1 <To or (b2) T1 ≧ To. The set temperature of the air blown from the external controller is, for example, about 10 to 20 ° C.

(B1) When T1 <To, that is, when the outside air temperature is higher than the set temperature for blowing air from the external control device to the clean room, it is necessary to perform a heat exchange operation with the external control device. The difference ΔTo = To−T1 is calculated, and the cooling water temperature required for the temperature difference ΔTo, that is, the cooling water temperature required for the heat exchange of the external controller is calculated, and this temperature is stored as A. Thereafter, the process proceeds to the next determination step (determination step 3 in FIG. 2).

On the other hand, if (b2) T1 ≧ To, that is, if the outside air temperature is lower than the set temperature for blowing air from the air conditioner to the clean room, the air conditioner may perform the air blowing operation. Since this does not become a factor in determining the minimum cooling water temperature required for the clean room system, the process directly proceeds to the next determination step (determination step 3 in FIG. 2).

Next, in the case of (b), in the judgment step 3, the temperature Ti in the clean room measured by a sensor or the like provided in the clean room and the set temperature T2 for blowing air from the inner conditioner into the clean room are further determined. Compare. The set temperature T2 of the blowout from the internal adjuster is, for example, about 20 to 23 ° C. If there is a temperature difference between the two, it is necessary to perform a heat exchange operation with the internal adjuster, calculate a temperature difference ΔTi = Ti−T2 in the heat exchange, and calculate the temperature difference ΔTi. The cooling water temperature required for replacement is calculated, and this temperature is stored as B.

In the case of (b), in the final judgment step 4, the cooling water temperature A required for the heat exchange of the external controller and the heat exchange required for the internal controller are determined as described above. The cooling water temperature B is the lowest cooling water temperature condition in the clean room air conditioning.

With such a control program, the temperature of the cooling water required for air-conditioning the clean room is calculated based on the measurement result of the outside air condition, and the refrigerator is instructed to operate at this temperature.

The control operation uses the same automatic calculation device as that used for the enthalpy calculation or a separate automatic calculation device, and continuously calculates the cooling water temperature based on continuously measured outside air conditions. By giving an instruction to the refrigerator, the operation of the refrigerator can be automatically controlled.

The control program used in the clean room air-conditioning control method according to the present invention is not limited to the one shown in the embodiment shown in FIG. Based on the measurement result, the cooling water temperature required for the operation of the external controller and the internal controller is calculated, and any device may be used as long as it can be instructed to operate the refrigerator at the temperature. . For example, in the control program as exemplified above, depending on the outside air condition, the configuration is such that the cooling water temperature necessary for heat exchange in the internal conditioner is taken into account,
Generally, the cooling water temperature required for dehumidifying or heat exchanging the outside air in the external conditioner is lower than the cooling water temperature required for exchanging the internal air in the internal conditioner, and Since the set temperature is almost determined by the load condition of the outside air conditioner, it is simpler to directly calculate the set temperature of the refrigerator by the enthalpy of the outside air calculated from the measured outside air temperature and humidity. It is also possible to use a simple control program.

The air-conditioning system used in the clean room control method according to the present invention is not particularly limited. At least, as shown in FIG. This is a system for controlling the humidity and temperature (and cleaning) of the atmospheric air flowing into the clean room by the air conditioner 30. The coolers 2 of the external conditioner 20 and the internal conditioner 30
The cooling liquid circulating through 2 and 31 is controlled to a desired temperature by a refrigerator, and the refrigerator can increase or decrease the degree of compression according to an indicated temperature (load), thereby changing the required power. Any configuration may be used as long as. Also, as the cooling liquid used,
Not limited to water, various cooling media can be used.

In the refrigerating compressor, the required power can be changed by changing the degree of compression. For example, various capacity control devices such as an unloading mechanism in a reciprocating compressor, a damper control in a centrifugal compressor, etc. , Vane control, bypass control, pre-rotation vane control, slide valve system in screw compressors, and various types of electric drive type compressors, such as speed control for controlling the number of revolutions of the electric motor. home,
An electric motor having a speed control mechanism is desirable because the power (electricity consumption) can be reduced most efficiently with respect to a reduction in load.

[0030]

As described above, according to the present invention, the outside air condition is measured, the required coolant temperature is calculated based on the result of the measurement, and the refrigerator is set so that the coolant has the temperature. Since the operation of the refrigerator is controlled, the refrigerator can be operated efficiently, and the work load on the compressor is reduced due to the performance characteristics of the refrigerator, and as a result, the amount of electricity used is reduced. Even in comparison with the case where the operation of the refrigerator is controlled by starting and stopping, it is possible to further save energy by making the operating conditions variable in this way. By taking this into consideration, the load on the refrigerator can be reduced, and the amount of electricity used can be reduced. .

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a typical apparatus configuration of a clean room system in a semiconductor factory.

FIG. 2 is a block diagram showing a series of flow of operation control of the refrigerator in one embodiment of the clean room air conditioning control method according to the present invention;

FIG. 3 is a schematic psychrometric chart.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Clean room 11 Clean room air blow-off part (filter) 20 External controller 21 Air filter 22 External controller cooler 23 External controller heater 24 External controller humidifier 30 Internal controller 31 Internal controller cooler 40 Refrigerator 50 Boiler

Claims (3)

[Claims] An air conditioning control method for a clean room, comprising measuring outside air conditions, calculating a coolant temperature required for operation of an external controller and an internal controller based on a result of the measurement, and calculating a refrigerator temperature at the temperature. A method for controlling the air conditioning of a clean room, comprising: 2. An outside air condition is measured, and the enthalpy of the outside air calculated from the measurement result is compared with an enthalpy of a set condition in a clean room. 2. The air conditioning control method for a clean room according to claim 1, wherein the coolant temperature is calculated and the operation of the refrigerator is controlled to the calculated temperature. 3. The measurement of the outside air condition is continuously performed, the measurement result is sequentially sent to an automatic operation device, and the calculation of the coolant temperature and the operation command for the refrigerator to the temperature are continuously performed in the automatic operation device. The air conditioning control method for a clean room according to claim 1 or 2, wherein the operation of the refrigerator is automatically controlled by performing the operation in an appropriate manner.