JPH05196258A - Air-conditioning facility - Google Patents

Abstract

PURPOSE:To permit easy cooling with cooling water having a high temperature by a method wherein return air, cooled through sensitive heat cooling, is mixed with outdoor air, whose temperature and humidity are regulated optimally, to supply it into a clean room. CONSTITUTION:Air, passed through a heat exchanger 61 provided in an air- conditioning unit 6 and cooled through sensitive heat cooling, is sent into a garret 44 by a fan 63 through a conduit 64. Air, regulated by an outdoor air regulating device 7 introducing outdoor air through an outdoor air intake 76 and regulating it so as to have optimum temperature and humidity, is supplied into the garret 44 through the conduit 74 by a fan 3. Both of the cooled air and regulated air, which are sent into the garret 44, are mixed with each other and is supplied into a clean room 43 through a clean room module 5. The temperature of air, cooled through sensitive heat cooling, is high in such a manner whereby cooling water, having higher temperature than the same so far, can be used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner which can save energy and is useful for air conditioning in clean rooms and constant temperature and humidity chambers.

[0002]

2. Description of the Prior Art The air conditioning equipment shown in FIGS. 5 and 6 is edited and published by the Society for Air Conditioning and Sanitary Engineering, Handbook of Air Conditioning and Sanitary Engineering, 2nd edition, published December 1, 1987, 〓-818. It is disclosed on the page. As shown in FIGS. 5 and 6, this is, for example, 25 ° C. after passing through the clean room 1.
Return air is discharged to the return plenum 11 under the floor. On the other hand, the outside air that has taken in the amount necessary to obtain the amount of supply air passes through the filters F1 and F2 in the outside air regulator 2 and then in the summer season, the temperature is 32 ° C and RH (relative humidity) is 70%. Has passed through CC21 and is below the dew point temperature of 11
Dehumidified by cooling to ° C, -2 ° C x RH50% in winter
Low temperature dry outside air passes through the HC 22 and the humidifier 23
It is heated and humidified to a temperature of 1 ° C and almost 100% RH, and is adjusted to air with a constant temperature and humidity throughout the year.

After the temperature and humidity have been adjusted to an appropriate level by the outside air regulator, the air is heated to a temperature of, for example, 12 ° C. by the fan 24, and the return plenum 1 under the clean room is used.
It is sent to 1. 25 ° above for return plenum 11
The mixed air is mixed with the return air of C, and the mixed air is sensiblely cooled at, for example, 22.5 ° C. to CC22 of another cooler 3 to, for example, 22 ° C. outlet air without dehumidification. , Juan 32 to the ceiling 12 of the clean room 1. The air sent to the attic 12 is air at 23 ° C and RH 45%, which is the design condition of the clean room.
It is supplied into the clean room 1 through the filter 13. It is such an air conditioning equipment.

[0004]

The change in state of the conventional air conditioning equipment is represented by the moist air diagram shown in FIG. Here, the SHF (sensible heat ratio) is approximately 1.0, and the absolute humidity is 0.
008 (Kg-water vapor / Kg-dry air) is almost constant. The return air at 25 ° C and the air at 12 ° C after the temperature and humidity of the outside air have been adjusted and passed through the fan 24 are mixed to obtain mixed air at 22.5 ° C. If the amount is taken from the outside air, then 12 × a + 25 × (1−a) = 22.
The expression 5 holds and a = 0.192. That is, the necessary intake amount of outside air in the moist air diagram of FIG. 6 is about 19.2% of the supply air amount.

That is, 80.8% of return air and 19.2% of air whose temperature and humidity have been adjusted are mixed to obtain 22.5 ° C.
Air is obtained, and then it is cooled to 22 ° C by CC31 of the cooler 3 and sent to the back of the ceiling to become the supply air of 23 ° C. That is, in the above-mentioned conventional air conditioning equipment, the cooler 3 is used for 22.
Sensible cooling of mixed air at 5 ° C to 22 ° C.

Since the cooler 3 cools the mixed air of 22.5 ° C. to 22 ° C., cooling water of 22 ° C. or lower is required. Practically, the temperature is about 15 ° C. considering the temperature variation. You need water. Usually, in order to obtain water at 15 ° C in a cooling tower, it cannot be obtained unless the wet-bulb temperature of the outside air is 13 ° C or lower, and if the humidity temperature of the outside air is higher than that, a refrigerator must be used. Therefore, the operating period of the refrigerator becomes long and consumes a lot of energy. The present invention solves the above-mentioned problems and provides an energy-saving type air conditioning equipment capable of easily cooling even high-temperature cooling water.

[0007]

DISCLOSURE OF THE INVENTION The gist of the present invention is, in an air conditioning apparatus for supplying air-conditioned air into a clean room, heat exchange for sensible cooling of return air after passing through the clean room. Device, an outside air conditioner that cools the taken-in outside air below the dew point and / or heats it to adjust the temperature and humidity to an appropriate temperature and humidity, and the sensible-cooled return air and the outside air to an appropriate temperature and humidity. The air conditioning equipment is characterized by comprising a mixing chamber for mixing the mixed air and a clean room module having a filter for supplying the mixed air into the clean room.

In the present invention, a cooling tower for cooling by sprinkling water and ventilation is provided, and a refrigerator connected downstream of the cooling tower. Normally, only the cooling tower is operated and only when the cooling tower alone cannot sufficiently cool, it is frozen. When the cooling machine is also operated and there is a risk of heating the cooling tower cooling water, a cooling device that allows only the refrigerator to operate by passing through a bypass pipe that does not pass the cooling tower, and cooling water obtained by the cooling device are A pipe line leading to the heat exchanger is provided, and the return air after passing through the clean room can be sensible cooled by the heat exchanger.

In the present invention, a pipe line is provided for guiding the cooling water after sensible cooling by the heat exchanger to the outside air conditioner, and the outside air conditioner is used to warm the outside air by the heat recovered by the heat exchanger to make it appropriate. The temperature and humidity can be controlled.

[0010]

The structure of the present invention is as described above. That is, it may be considered that the air of the outside air conditioner 2 shown in the above-mentioned conventional technique is sent to the secondary side of the cooler 3. By doing so, the load of the cooler 3 for sensible cooling under the same temperature and humidity conditions as in the prior art will be compared as follows. The outside air conditioner 2 takes in 19.2% of the total supply air, and adjusts the temperature and humidity of the outside air. The air at 12 ° C. is sent by the fan 24 between the secondary side of the CC 31 of the cooler 3 and the upstream side of the fan 32. On the other hand, only the return air of 25 ° C is cooled to t ° C by CC31 of the cooler 3, and is mixed with the air whose temperature and humidity are adjusted to 12 ° C and is sent to the ceiling 12 by the fan 32. It is assumed that it is supplied into the clean room 1 through -13.

Here, t ° cooled by CC31 of the cooler 3
The C air 80.8% and the temperature and humidity adjusted 12 ° C air 19.2% are mixed to form a 22 ° C outlet air. Therefore, the following equation holds from the temperature balance. From t × 0.808 + 12 × 0.192 = 22 × 1 0.808t = 19.72, t = 24.38 ° C. Therefore, CC31 of the cooler 3 may be cooled to 25 ° C, and the return air of 80.8% of the supply air may be cooled to 24.38 ° C. That is, the temperature at which sensible heat is cooled in the heat exchanger of the cooler is 25 ° C. to 24.38 ° C. in the present invention, compared to 22.5 ° C. to 22 ° C. in the prior art, and the temperature difference is the Although it increases from 0.5 ° to 0.62 °, since the amount of air to be cooled is 80.8% of that in the conventional technique, the product of the temperature difference and the amount of air is the same, so the amount of cooling heat is also the same.

However, the temperature of the air cooled by the heat exchanger is 24.38 ° C. and 2.38 ° C. as compared with 22 ° C. in the prior art.
Since the temperature is higher by ° C, the cooling water can be cooled by the cooling water having a temperature higher by 2.38 ° C than the cooling water of the prior art. The fact that the temperature of the cooling water may be high means that the cooling water can be obtained in an energy-saving manner because the period obtained in the cooling tower is long and the period requiring a refrigerator is short. When cooling water having the same temperature as that of the conventional technique is used, the logarithmic mean temperature difference (the temperature difference between the fluid inside and outside the heat exchanger partition wall) becomes large, and the heat transfer area of the heat exchanger can be made small. I can. That is, the cooler can be downsized.

Next, as a cooling water cooling device used for a heat exchanger for cooling the return air of the clean room, a cooling tower and a refrigerator are connected downstream of the cooling tower, and normally only the cooling tower is operated. Cooling is operated only when the cooling tower alone cannot sufficiently cool, and when there is a risk of heating the cooling water in the cooling tower, only the refrigerator is operated by passing through a bypass line that does not pass the cooling tower. A device can be used. In this cooling device, the cooling water is cooled by sprinkling and ventilation in the cooling part of the cooling tower, and the cooling water cooled by the cooling tower is cooled only when the outside air wet bulb temperature is high and the cooling tower alone cannot cool it to a predetermined temperature. The refrigerator is also operated depending on the temperature, and when the wet-bulb temperature is high and the return cooling water is heated in the cooling tower, only the refrigerator can be operated and cooled without passing through the cooling tower.

Therefore, in the wet-bulb temperature state where cooling can be performed only by the cooling capacity of the cooling tower, the refrigerator is stopped and cooling can be performed by operating only the cooling tower. As before, the temperature of the return air of the clean room is about 25 ° C. To cool the air at this temperature with the heat exchanger, cooling water of about 18 ° C. may be used, and to obtain the cooling water of this temperature with the cooling tower, the wet-bulb temperature of the outside air may be about 16 ° or less. This state is from 1951 to 1 described in the science chronological table 1986 edition shown in FIG.
As can be seen from the monthly average wet-bulb temperature in the Tokyo region up to 980, it is possible to obtain the period except the summer season throughout the year. Therefore, it is possible to obtain the cooling water of about 18 ° C almost all year by operating only the cooling tower. Therefore, the operating time of the refrigerator is significantly shorter than that of the conventional cooling device that cools only with the refrigerator, resulting in energy saving.

In the present invention, the operating temperature of the heat exchanger used for sensible cooling (air temperature before cooling, temperature of cooling water) is particularly high. Therefore, when a cooling device in which a cooling tower and a refrigerator are combined is used, the cooling tower is cooled. Energy saving
Can be measured. Therefore, it is very convenient as a device for obtaining cooling water for cooling the return air of about 25 ° C. from the clean room.

Next, the return water of the clean room is sensible cooled by a heat exchanger, and the cooling water is introduced to an outside air conditioner for taking in outside air and adjusting the temperature and humidity, and after cooling by the heat exchanger. The temperature and humidity of the outside air can be adjusted by the outside air conditioner using the recovered heat. An outside air conditioner that adjusts the outside air to an appropriate temperature and humidity first warms the taken-in air in a preheat portion, and then in a cooling portion, a dew point temperature (for example, 7) of a target absolute humidity.
Dehumidification is performed by cooling to (° to 11 ° C), and then the dehumidified air is warmed at the reheat portion and sent out. When the outside air is in a low temperature dry state below the dew point temperature such as in winter, it is not necessary to cool it in the cooling section, so the preheat section and the reheat section are heated and humidified to adjust the temperature to a predetermined temperature and humidity. At this time, the cooling water after sensible cooling of the return air of the clean room is 20 ° C to 23 ° C.
Is sufficiently higher than the target dew point temperature to be cooled in the cooling section of the outside air conditioner, and this cooling water is guided to the preheat portion and the reheat portion of the outside air conditioner so that the air in a low temperature dry state is predetermined. The temperature and humidity can be adjusted. Therefore, compared with the one using an electric heater, the heat recovered after cooling the clean room return air is used, which saves energy.
You can adjust the outside air with.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of an air conditioner of the present invention, which is applied to a clean room. A clean room 43 and a ceiling space 44, which are partitioned by a ceiling 41 and a wall 42, are provided in the building 40, and the clean room 43 is sucked through a suction port 62 at a lower portion of the clean room at a predetermined interval. Air-conditioning unit 6 for sensible cooling of the air in the cabin
Is provided. The air conditioning unit 6 is provided with a heat exchanger 61, and the air that has passed through the heat exchanger 61 and has been sensible cooled is sent to the ceiling space 44 by the blower 63 through the conduit 64.

On the other hand, outside the clean room 43, an outside air conditioner 7 is installed which takes in outside air from an outside air intake port 76 and adjusts it to an appropriate temperature and humidity. The air conditioned by the outside air regulator 7 is sent by the fan 73 to the ceiling 44 through the conduit 74. The preheat portion 7 is provided in the outside air conditioner 7.
4, a cooling unit 71 and a reheat unit 72 are provided in order,
A cooling unit 71 is provided below the outside air passage adjusting passage 79.
A refrigerator 77 is provided to obtain a cooling heat source for cooling the. In the refrigerator 77, the cooling unit 71 evaporates the liquefied refrigerant compressed by the compressor 78 to cool the air, and the condenser 7
The action of radiating heat at 5 is repeated. For the heat radiation of the condenser 75, cooling water cooled by the cooling tower 8 installed outside the building 40 is used.

When the outside air is hotter and more humid than the inside of the room 43, first, the outside air intake air is warmed by the preheat portion 74 so that the outlet temperature of the cooling portion 71 becomes the dew point temperature of the absolute humidity, and the cooling portion 71. It is cooled to the target absolute humidity dew point temperature. To bring the temperature of the clean room to 23 ° C and 40% relative humidity when the outside air is 33 ° C and 60% relative humidity,
Absolute humidity 0.0062Kg / Kg (DA) in the cooling unit 71
Cool to a dew point of 7 ° C. This temperature is controlled by the preheat portion 74 and the cooling portion 71 so as to be constant throughout the year. After being dehumidified here, since the conduit 74 connecting to the ceiling 44 is condensed as it is, the rehearsal section 72 is
Then, it is heated up to about 12 ° C and is blown into the ceiling space 44 by the fan 73.

In the winter, when the temperature is lower than the above target dew point temperature and is in a dry state, the cooling unit 71 and the refrigerator 77 are stopped, and the outside air taken in is warmed by the preheat unit 74 and the target temperature is 7 ° C. The target temperature and humidity are controlled by further heating and humidifying the reheat portion 72. The heat sources of the preheat portion 74 and the reheat portion 72 are the condenser 7 while the refrigerator 77 is operating.
The heat radiated by 5 is used. When the refrigerator 77 is stopped, bypass pipes 65 and 66, which are pipes between the cooling device 9 and the air conditioning unit 6 which will be described later, are opened, and the heat recovered by the air conditioning unit 6 is recovered from the preheat portion 74 and the reheat portion. The temperature is controlled to 72 by controlling to a predetermined temperature and humidity, and the heat source is effectively used to save energy.

The clean room 4 is provided outside the building 40.
A cooling device 9 for sending cooling water of a predetermined temperature is installed in the heat exchanger 61 of the air conditioning unit in the unit 3. As shown in FIG. 3, this cooling device 9 is composed of an evaporative cooler 91 having cooling coils arranged in a plurality of stages, a sprinkler header 92 for sprinkling water on the evaporative cooler 91, and a fan 93 for ventilating the cooler 91. The tower 94 and a refrigerator 95 downstream of the tower 94 as a booster
The refrigerator 95 is equipped with a compressor 96 and a cooling tower 94.
It consists of an evaporative condenser 97, an expansion valve 98, and an evaporator 99 arranged inside, and operates the refrigerator 95 only when the cooling tower section 94 alone cannot sufficiently cool the cooling tower section 94. After cooling with an evaporative cooler, it is further cooled with an evaporator 99 of a refrigerator 95, and the wet-bulb temperature of the outside air is low, so that cooling water of a predetermined temperature is obtained by sprinkling water only in the cooling tower section 94 and latent heat cooling by ventilation. If so, the operation of the refrigerator 95 is stopped.

When the wet-bulb temperature of the outside air is high and the cooling water is heated in the cooling tower section 94, the valve 101 of the bypass pipeline 100 is opened and the valve 102 of the pipeline going to the cooling tower section 94 is closed. Instead of passing through the cooling tower section 94, it is passed directly to the evaporator 99 of the refrigerator 95 for cooling. According to this cooling facility 9, the sprinkling water amount of the cooling tower section 94 or the air flow rate of the fan 93 is controlled, the number of compressors 96 of the refrigerator is controlled, or the capacity of the compressor 96 is controlled. Cooling water having a predetermined temperature of about C to 25 ° C. is obtained by saving energy. Particularly, the higher the target cooling temperature is, the greater the energy saving effect is, and it is very suitable as a device for obtaining the cooling water of the return air of about 24 ° C. after passing through the clean room 2.

In the clean room 43, the temperature of the air supplied from the clean room module 5 of the ceiling 41 rises due to heat generated by a machine or a person, and this air is heat-exchanged from the suction port 62 of the air conditioning unit 6. It is cooled to a predetermined temperature through the air blower 61, and is blown into the ceiling space 44 by the blower 63 through the conduit 64. After the outside air is taken into the outside air adjuster 7 from the outside air intake port 76 to adjust the temperature and humidity, the fan 7
The air is sent to the ceiling 3 through the conduit 74 by means of 3. Both air supplied to the ceiling 3 are mixed and supplied from the clean room module 5 shown in FIG. 2 into the clean room 43. In addition, an amount of air corresponding to the outside air taken in is discharged to the outside of the clean room.

The clean room module 5 is provided with a HEPA filter 51 on the clean room 2 side, a pressurized air unit 52 on the upstream side, and a blower 53 on the upstream side, and a suction port 54 of the blower 53 is above the ceiling. The air in the space 44 above the ceiling is sent to the inside of the clean room 43 through the HEPA filter 51. In the above, for example, the air-conditioning unit 6 has a blowing capacity of 42 CMM (m ³ / mi).
In n), five air conditioning units 6 are provided with five clean room modules 5 each having a blowing capacity of 10 CMM. Further, the air whose ambient air is taken in and the humidity of which is adjusted is sent by the fan 73 to the back of the ceiling at 4 CMM per air conditioning unit 6. In this way, the clean room module 5 sends 50 CMM of air into the clean room, and the pressure of each part is set so that the pressure inside the clean room> the pressure above the ceiling> the atmospheric pressure. .. In this way, clean room 4
Cleanliness is enhanced by preventing dust from entering the inside.

FIG. 4 shows an air conditioning equipment showing a second embodiment of the present invention. In this embodiment, an exhaust port is provided on the floor surface 45 so that the supply air sent from the clean room module 5 on the ceiling 41 into the clean room 43 descends directly below and flows under the floor in a substantially laminar flow state. There is. An air conditioning unit 6 is installed under the floor 46. The return air is cooled by the heat exchanger 61 of the air conditioning unit 6, passes through the conduit 64, and the ceiling space 4
It is sent to 4. Further, the outside air conditioner 81 of the present embodiment is one in which the outside air conditioner 7 of the first embodiment and the cooling tower 8 are integrated, and the outside air passage adjusting passage 82, the refrigerator section 83, and the cooling tower section of the refrigerator are integrated. It is made compact by integrating with 84.
Further, the preheat portion PH of the outside air passage adjusting passage 82 and the
The heat exchanger 61 of the air-conditioning unit 6 is used as a heat source for the heating section RH.
In order to use the cooling water after the heat exchange in (1), a heat exchanger HE for guiding the cooling water from the pipeline between the air conditioning unit 6 and the cooling device 9 to exchange the heat is provided. A cooling device 9 for the air conditioning unit is the same as that described in FIG.

[0026]

As described above, according to the present invention, since the temperature of the air for sensible heat cooling is high, it is possible to use cooling water having a higher temperature than before. Therefore, the period of operating the refrigerator can be shortened as much as possible. When using cooling water of the same temperature,
A large amount of heat exchange per unit flow rate of the heat exchanger can be obtained. Therefore, the amount of cooling water can be reduced, the number of heat exchangers can be reduced, or a small heat exchanger can be used. Therefore, air conditioning can be performed with energy saving.

[Brief description of drawings]

FIG. 1 is a diagram of an air conditioner for explaining a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the clean room module 5 of FIG.

3 is a cooling facility for obtaining a cooling heat source for the air conditioning unit of FIG.

FIG. 4 is a diagram of an air conditioning equipment showing a second embodiment of the present invention.

FIG. 5 is a diagram of a conventional air conditioning equipment.

FIG. 6 is a diagram showing the moist air diagram of FIG. 5;

FIG. 7 is a diagram showing monthly average wet-bulb temperatures in the Tokyo region from 1951 to 1980.

[Explanation of symbols]

 6 Air-conditioning unit 7, 81 Outside air regulator 8 Cooling tower 9 Cooling device 43 Clean room 44 Attic 46 Underfloor 61 Heat exchanger 62 Suction port 71 Cooling section 76, 82 Outside air passage adjusting passage 77, 83, 95 Refrigerator 79, 99 evaporator (evaporator) 91 evaporative cooler 94 cooling tower section 95 refrigerator 100 bypass line 101, 102 valves

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ken Nakagawa 2 Daifuku, Kuwana City Hitachi Metals & Metals Co., Ltd. Kuwana Factory

Claims (3)

[Claims] 1. An air conditioning system for supplying air-conditioned air into a clean room, wherein a heat exchanger for sensible cooling of the return air after passing through the clean room and the outside air taken in are below the dew point. An outside air regulator that cools and / or heats to adjust to an appropriate temperature and humidity, and a mixing chamber that mixes air in which the return air is sensible cooled and air in which the outside air is adjusted to an appropriate temperature and humidity, An air conditioning equipment comprising a clean room module having a filter for supplying the mixed air into the clean room. 2. A cooling tower for cooling by sprinkling water and ventilation, and a refrigerator connected downstream of the cooling tower. Normally, only the cooling tower is operated, and the refrigerator is operated only when the cooling tower alone cannot cool sufficiently. When there is a possibility that the cooling tower is also operated by heating the cooling water, a cooling device that allows only the refrigerator to operate by passing through the bypass pipe that does not pass through the cooling tower, and the cooling water obtained by the cooling device are The air conditioner according to claim 1, further comprising: a pipe line leading to the heat exchanger, wherein the return air after passing through the clean room is sensible-cooled by the heat exchanger. 3. A pipe line is provided for guiding cooling water after sensible cooling by the heat exchanger to the outside air conditioner, and the outside air conditioner warms the outside air by the heat recovered by the heat exchanger to obtain an appropriate temperature. The air conditioner according to claim 1, wherein the air conditioner is controlled to humidity.