JPH04113136A - Clean room using direct expansion type heat exchanger - Google Patents

Abstract

PURPOSE:To control temperature and humidity without using a freezer by a method wherein a direct expansion type dry coil in which a refrigerant is vaporized is arranged in an air circulation passage, an air cooler being the vaporizer of a heat pump device is arranged in an air intake route, and the temperature of the intake open air is regulated to a set dew point value. CONSTITUTION:A direct expansion type dry coil 10 in which a refrigerant is vaporized is arranged in an air circulation passage, and an air cooler 11 being the vaporizer of a heat pump device is arranged in an air intake route in a system. A heat pump device body 13 serving to function the dry coil 10 as the vaporizer of a freezing cycle is installed outside a system, and the condensing heat of a condenser 15 is emitted in the open air through running of a fan 16. The surface temperature of the dry coil 10 is regulated to a value not reduced to a value lower than the dew point temperature of air passing therethrough. Air passing the dry coil 10 is cooled without generating drain, and an internal generating heat in a clean room can be emitted in the open air through the condenser 15.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has the following features: This invention relates to a clean room in which temperature and humidity can be adjusted by inputting only air energy.

[Conventional technology]

A large number of fan filter units (abbreviated as FFU) are placed on the ceiling surface, and by operating the fan of each FFU, air from the attic space is blown downward into the room through the HEPA filter layer of each FFU. Clean rooms are well known, but the best way to adjust the temperature and humidity in a lean room is to place an air conditioner in the air circulation path that guides the air blown into the room back into the attic space.
! He was a connoisseur. This air conditioner uses a cooling coil through which cold water flows, and the cold water (or brine) is adjusted to a temperature close to the dew point temperature of the circulating air produced by the refrigerator.
It was common practice to cool the air by passing water through the cooling coil.

In addition, some of the air that circulates within the system is exhausted or leaked out of the system, and it is necessary to take in an appropriate amount of outside air into the system. will be installed. The primary mission of this external temperature machine is to adjust the circulating air inside the system and the outside air, which has a different dew point temperature, to a similar dew point temperature.To this end, a cooling coil and a humidifier are installed to cool and dehumidify the outside air. be done. Cold water or brine produced by the refrigerator is also passed through this cooling coil, and the surface temperature of the cooling coil is controlled so that it matches the set dew point temperature, and if necessary, a humidifier is operated to humidify. .

[Problem that the invention seeks to solve]

It is necessary to pass cold water or brine at a set temperature through the cooling coil of the air conditioner placed in the air circulation path and the cooling coil placed in the external temperature machine. The production of chilled water or brine requires a refrigerator, and chilled water piping is essential, as well as cooling towers and other auxiliary equipment, making the equipment extremely expensive.

For this reason, in conventional clean rooms, not only does the initial cost increase, but it is not easy to modify the heat source equipment to match changes in heat load, such as changing lines or changing work volume. There were problems in that it was difficult to secure space for the heat source equipment, and it was difficult to modify and piping when making changes.

The present invention aims to solve such problems.

[Means to solve problems]

According to the present invention, in a clean room in which clean air is blown into the room from a plurality of fan filter units (FFU) installed on the ceiling surface, the air blown into the room flows through all or part of the FFU. A direct expansion type dry coil in which the refrigerant evaporates is placed in the air circulation path into which the refrigerant is sucked into the system.An air cooler, which is the spring generator of the heat pump device, is placed in the outside air intake path into the 3 system. To provide a clean room using a direct expansion type heat exchanger, characterized in that the outside air taken in by the dry coil is adjusted to a set dew point temperature, and the evaporation temperature of the refrigerant is adjusted so as not to generate condensate in the dry coil.

At this time, the dew point temperature control of the outside air taken in is adjusted by controlling the rotation speed of the compressor in the heat pump device so that the detected value of the dew point sensor installed on the outlet side of the air cooler falls within the set range. In addition, a reversible heat pump is used as the heat pump device, and when the target is outside air with low temperature and low dew point temperature in winter, the air cooler is operated as a condenser of the heat pump device, thereby reducing the temperature of the outside air with low temperature and low dew point temperature. Perform heating.

[Effect]

In the clean room of the present invention, direct expansion type coolers are arranged in both the air circulation path within the system and the intake air path. Therefore, the necessary temperature and humidity control can be performed directly using electrical energy alone, without using a refrigerator.

〔Example〕

FIG. 1 shows an embodiment of a clean room according to the present invention, in which a large number of FFUs 3 are horizontally adjacent to each other on the ceiling surfaces of clean room spaces 1 and 2. These FFtJ3 have a HEPA filter or ULPA filter 5 attached to the lower opening of a casing in which a fan 4 is installed, and by driving the fan 4, the air in the attic space 6 is purified by the filter 5. Blows downward into the clean room space. In the illustrated example, the clean room space consists of a work space 1 and a manufacturing machine room space 2. The air blown into the clean room space enters the underfloor space 8 through the perforated floor 7, and returns from the underfloor space 8 to the attic space 6 through the vertical path 9. Like this F
The clean room itself, which forms an air circulation path by driving the fan of the FU 3, is well known.

In the present invention, in such a lean room,
A direct expansion type dry coil 10 in which two refrigerants evaporate is placed in the air circulation path where air blown into the clean room space is sucked into all or part of the FFU 3, and a heat pump device is installed in the outside air intake path into the system. It is characterized by the arrangement of an air cooler 11, which is an evaporator.

The dry coil 10 does not pass cold water as in the past, but consists only of a finned coil through which refrigerant expands, and has no drain pan or fan. In the illustrated example, this is placed on the ceiling of the vertical path 9, and the attic space 6
This is where air passes through before entering the room. Also as shown.

A part of the FFU 3 is also replaced in the ceiling of the manufacturing machine room space 2 with a dry coil 10', and a part of the air blown into the manufacturing machine room space 2 passes through this tri-coil 10 and reaches the ceiling of the manufacturing machine room space 2. If the FFU 3 located at
It is also possible to change the blowout temperature of the FFU from that of other FFUs.

A heat pump device main body 13 for making these dry coils 10 function as a generator of the refrigeration cycle is installed outside the system. This heat pump device main body 13 has a pressure lit machine 14 inside the casing. Condenser 15. A fan 16 is attached, and between the main body 13 and the dry coil 10, the refrigerant discharged from the compressor 14 is condensed in the condenser 15, then throttled by the expansion valve 17 and expanded in the dry coil 10. to evaporate and return to the compressor 14 again,
Refrigerant piping is installed.

The heat of condensation in the condenser 15 is released to the outside air by driving the fan 16. The surface temperature of the dry coil IO is adjusted so as not to fall below the dew point temperature of the air passing therethrough.

This can be done by controlling the rotation speed of the compressor 14 based on the detected value of a dew point sensor that detects the dew point of the air that is about to pass through. In this way, the air passing through the dry coil 10 is cooled without generating condensate, and the heat generated internally within the clean room can be radiated to the outside air through the condenser 15.

On the other hand, part of the air inside the system is exhausted outside the system through the exhaust fan 18 or due to leakage due to opening and closing of doors, etc., but outside air is taken into the system to maintain positive pressure inside the system. This is necessary. In the present invention, an air cooler 11 is installed in this outside air intake path, which also functions as an evaporator of the top pump device. In the illustrated example, this air cooler 11 has an outer circle I! This outer circular machine 19 is installed within the system. The device configuration of this outer circular machine part is shown in an enlarged scale in FIG.

As shown in FIG. 2, the outer circular machine 19 has prefilters 21 . Air cooler 11a, llb, humidifier 22. Fan 23. )IE
It houses a PA filter 24, and an air cooler 11a,
A drain pan 25 is installed below the llb and humidifier 22, and a dew point sensor 26 is installed at the discharge position of the fan 23.
is installed.

As described above, the air cooler 11 functions as a heat generator of the heat pump device, and is a direct expansion type heat exchanger made of a finned coil. As shown in FIG. 1, a heat pump device main body 27, which allows the air cooler 11 to function as an evaporator of the refrigeration cycle, is installed outside the system. This heat pump device main body 27 includes a compressor 28, a condenser 29. A fan 30 is attached, and between this main body 27 and the air cooler 11, the refrigerant discharged from the compressor 28 is condensed in the condenser 29, and then throttled by the expansion valve 31 and transferred to the air cooler 11. It expands and evaporates,
Refrigerant piping is arranged to return to the compressor 28 again.

The heat of condensation in the condenser 29 is released to the outside air by driving the fan 30. In the illustrated example, two air coolers are attached to one heat pump device, as shown by lla and llb. This is because the latent heat of vaporization of the refrigerant (for example, R22) is smaller than that of water.

By installing a plurality of air coolers in this way, the air can be sufficiently cooled to the intended dew point temperature.

In this way, the outer circular machine 19 adjusts the intake outside air to the set dew point temperature and introduces it into the system.
Dehumidifier mote and humidifier 22 that cool and dehumidify with air cooler 11
For example, two operating modes, such as a humidification mode in which steam is released, are selected depending on the situation.

In the dehumidification mode, the n-point sensor 26 detects the dew point temperature of the air on the discharge side of the air cooler.

The rotation speed of the compressor 28 is controlled so that this detected value falls within the set range. More specifically, as shown in FIG. 2, an intended dew point is set with the humidity controller 32, and the rotation speed of the compressor is adjusted so that air having a dew point of this set value passes through the dew point sensor 26. It is adjusted by an inverter 33. Therefore, the surface temperatures of the air coolers 11a and 11b are determined as they occur, which is fundamentally different from the conventional case where the coil surface temperature is controlled. The condensed water generated by this cooling and dehumidification is received by the drain pan 25 and discharged to the outside of the machine.

In the warming mode, humidifier 22 releases water vapor into the outside air stream to increase humidity. In this case as well, dew point sensor 2
Control the amount of water vapor so that the detected value at step 6 falls within the set range.
It is controlled by the B valve 34. This guy! This mode is generally applied in winter when outside air conditions are low temperature and low humidity.2 In times when this dehumidification is not required, it is sometimes advantageous to heat the outside air before introducing it into the system. This configures the heat pump device as a reversible heat pump,
So that the air coolers 11a and 11b serve as air heaters,
The heat pump device may be operated in heating mode.

FIG. 3 shows an example of refrigerant piping for this switching type heat pump, in which the cooling cycle shown by the solid line and the heating cycle shown by the broken line can be switched by four-way valves 35a and 35b. In the heating cycle, lla,
Ilb serves as a condenser of the heat pump, and 29 serves as an evaporator, and the outside air taken in can be heated to the required temperature in the condensers 11a and Ilb.

〔effect〕

As explained above, in the clean room according to the present invention, the internally generated load is treated drainlessly by the direct expansion type dry coil 10, so there is no need for drain piping. It also eliminates the need to use a refrigerator to create cold water or brine, and eliminates the need for refrigerators, cooling towers, and other large-scale heat source equipment. In addition, since cooling and dehumidification is performed by the direct expansion air cooler also in the outside chamber, heat source equipment such as a refrigerator or a cooling tower is not required here either. Moreover, this air cooler can also be used as an air heater if necessary. Therefore, it is sufficient to input only electrical energy as a heat source for the temperature and humidity of 1li1 for the clean room, which saves equipment and space, and also reduces the amount of construction work required when constructing a clean room (as a result, the construction period is significantly reduced). As a result, even when creating a clean room in an existing building, or when the internally generated load increases or decreases due to line changes or changes in usage, or the clean room volume increases or decreases, the construction period is extremely short. and can be handled economically.

[Brief explanation of drawings]

Fig. 1 is a schematic cross-sectional view showing an example of a clean room according to the present invention, Fig. 2V is a schematic cross-sectional diagram showing an enlarged view of the outer circular machine part of No. 1 FIG. 7 is an equipment layout system diagram showing another refrigerant circuit. 1.2...Clean room space 3...Fan filter unit 7) (FFU). 6. Attic space 10. Direct expansion type dry coil 11. Direct expansion type air cooler 13. Dry coil heat pump device main body. 19... External circular machine. 26...Dew point sensor 27...Air cooler heat pump device body 32...
Humidity controller 33... Inverter.

Claims (5)

[Claims] (1) In a clean room where clean air is blown into the room from multiple fan filter units (FFU) installed on the ceiling, air circulation path where the air blown into the room is sucked into all or part of the FFUs. To,
A direct expansion type dry coil is installed in which the refrigerant evaporates,
An air cooler, which is the evaporator of the heat pump device, is placed in the outside air intake path into the system, and this air cooler adjusts the intake outside air to the set dew point temperature. A clean room that uses a direct expansion heat exchanger that adjusts the evaporation temperature. (2) The air cooler, which is the evaporator of the heat pump device,
The clean room according to claim 1, wherein the clean room is arranged in an outdoor conditioner equipped with a HEPA filter, a fan, and a humidifier. (3) The dew point temperature of the intake outside air is adjusted by controlling the rotation speed of the compressor in the heat pump device so that the detected value of a dew point sensor installed on the outlet side of the air cooler falls within a set range. clean room. (4) The air cooler, which is the evaporator of the heat pump device,
The clean room according to claim 1, wherein a plurality of clean rooms are installed for one heat pump device. (5) The air cooler, which is the evaporator of the heat pump device,
2. The clean room according to claim 1, wherein the clean room is operated as a condenser of a heat pump device when the outside air at low temperature and low dew point temperature in winter is targeted.