JP4200523B2 - Air conditioning system for precise temperature control of local space - Google Patents

Description

  The present invention relates to an air conditioning system for precisely controlling the temperature of a local space that is easily affected by temperature fluctuations in the surrounding environment and that is used for a work target substance.

In order to reduce the temperature fluctuation of the work space and the space surrounding the target substance, etc., the general method is to air-condition the entire room, and control within the range of ± 1 ° C to ± 3 ° C within the general air conditioning level range of 18 ° C to 27 ° C Is possible. However, in order to further reduce the temperature fluctuation range and to precisely control the fluctuation range from 0.1 ° C. to 0.01 ° C. or more, the equation (1)
Q ≧ q ÷ 1.2 ÷ 0.24 ÷ | t | Equation (1)
| t | ≧ q ÷ Q ÷ 1.2 ÷ 0.24 Expression (2)
Q: Required air volume of air conditioner (m ³ / H)
q: Total heat load (Kcal / H)
1.2: Specific gravity of air (at 20 ° C) (kg / m ³ )
0.24: Specific heat of air (Kcal / kg ・ ℃)
t: Temperature accuracy (° C)
Therefore, the air flow must be 10 to 100 times or more. Accordingly, the size of the air conditioner increases in proportion to the air volume, the equipment cost increases, and the energy cost also increases.
Therefore, a method is adopted in which the entire room is primary air-conditioned, temperature fluctuations are stabilized, and only necessary portions are surrounded by walls, and air that is locally temperature-controlled with high accuracy is blown as secondary air-conditioning (Patent Document 1). reference).

One example will be described with reference to FIG.
The entire room 1 composed of heat insulating panels is used as a primary air conditioning area 2 and a primary air conditioner 7 having a refrigerator 3, a cooling coil 4, a heater 5, a fan 6, etc. is installed outside the room 1 (or inside). The conditioned air of the primary air conditioner 7 is blown out from the outlet 9 of the chamber 1 into the primary air conditioning area 2 through the supply duct 8. In the primary air-conditioning area 2, only a necessary part is surrounded by a wall body 10 made of a heat insulating material or the like to form a precision air-conditioning area (secondary air-conditioning area) 11.

  In the precision air conditioning area 11, a secondary air conditioner 16 having a refrigerator 12, a cooling coil 13, primary and secondary heaters 14, a blower 15 and the like for setting the air introduced from the primary air conditioning area 2 to a predetermined temperature. The air-conditioning air of the secondary air conditioner 16 is guided by the duct 17 and blown out to the precision air-conditioning area 11 through the hepa filter 18 to precisely control the temperature. However, the conditioned air in the duct 17 cannot reduce the amount of heat passing through even if the wall 10 of the secondary air conditioner 16 is difficult to pass heat as a heat insulating material or heat insulating material, and the influence of the primary air conditioning area 2 Will receive.

For example, temperature fluctuation in the primary air-conditioning area 2 is 2 ° C. (23 ° C. to 25 ° C.), supply duct surface area 6 m ² , supply duct temperature (precise temperature area predetermined temperature) 23 ° C., heat transmissivity 0.42 (in clean room) insulation panels used), if the process air volume 50 m ³ / min precision temperature area, transfer heat heat from the primary air conditioning area 2 in the duct 17, by the equation (3)
Q = K (t1−t2) A (3)
Q: Heat transfer (Kcal / h)
K: Thermal conductivity (Kcal / m ² · h · ° C)
t1, t2: fluid temperature on both sides
A: Surface area of the wall (m ² )
Q = 0.42 × (25-23) × 6 = 0.04 Kcal / h
The temperature change of the air in the supply duct 17 due to the amount of heat transferred is given by equation (2)
t ≧ 5.04 ÷ 50 ÷ 60 ÷ 1.2 = 0.0058 ° C
It becomes. In general, there is no particular problem with such a temperature change, but a temperature change of 0.01 ° C. to 0.0001 ° C. is currently a problem in the field of precision electronic processing.

However, even in the method using a secondary air conditioner, when the temperature accuracy is controlled precisely over ± 0.01 ° C, the primary air conditioning accuracy is reduced to reduce the total heat load q as shown in Equation (2). It is necessary to control to near the required temperature accuracy or to increase the air volume of the secondary air conditioner, resulting in the disadvantage that the air conditioner dimensions, energy cost and equipment cost increase.
JP 2004-184010 A

  An object of this invention is to obtain the air-conditioning system which performs precisely the temperature control of the air conditioner of the space surrounding work space or work object in view of said point.

In the first aspect of the invention, the temperature is precisely adjusted by an air conditioner having a blower connected to the supply duct, a cooling coil, a heating coil, and a plurality of temperature fluctuation absorption units, and the conditioned air is supplied to the precision temperature area. Equipment for heating, cooling, etc. and air supply ducts to be sent are arranged inside the two-layer structure, and the outside air of the equipment and air supply ducts arranged on the inside is returned to the air conditioner from the precision temperature area. A return duct to the air conditioner to be returned is provided, and a return air duct case is provided that surrounds the most downstream portion of the air-conditioning air supply duct and blows out the conditioned air to the precision temperature area and continues to the return duct.

In the present invention, the precision temperature area, which is the processing space surrounding the work object, is double insulated by the housing that houses the work object and the return air that surrounds the housing. The return air is the air that has flowed out of the processing space, and the temperature thereof is very close to the temperature of the processing space. As a result, if the air in the processing space of the casing is surrounded by a predetermined target temperature, it is effective, and the casing is also insulated twice, resulting in excessive insulation. High-accuracy temperature control is possible without processing.
For the reasons described above, highly accurate temperature control is possible even when the amount of flowing air is small, and the size of the air conditioner, energy costs, equipment costs, etc. can be reduced by reducing the amount of air flow.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic longitudinal side view of the air conditioning system 20 of the present invention. In the air conditioning system 20 of the present invention, a precision temperature area 22 constituted by a casing 21 and an air conditioner 23 are connected by a duct 26 in which a temperature-controlled air supply duct 24 is surrounded by a return duct 25. The precision temperature area 22 has a rectifying member such as a hepa filter 28 between the rectifying box 27 provided on the back surface thereof. The shape of the precision temperature area 22 is not necessarily constant, and the basic concept is that air that has been controlled and stabilized is fed into an area where the temperature is to be precisely controlled, and the area is surrounded by return air. The casing 21 and the supply duct 24 are surrounded by a return air duct case 25a, and the return duct case 25a is connected to the return duct 25. If the return duct case 25a cannot be installed, a flexible duct can be used instead. In this case, the precision temperature area 22 and the rectifying box 27 are surrounded by a heat insulating material 29, and a heat insulating process corresponding to the temperature, accuracy, and air volume is performed.

  A suction opening 30 of the return duct case 25 a is provided in front of the precision temperature area 22, and the front door 31 of the housing 21 can be exhausted by the positive pressure in the precision temperature area 22. As described above, the duct case 25 a surrounds the precise temperature area 22, that is, the casing 21 and the rectification box 27, and also surrounds the periphery of the joint portion between the rectification box 27 and the supply duct 24. For this reason, the supply air at the end of the supply duct 24 is surrounded by the return air of the stable temperature returned from the precision temperature area 22, and the supply air temperature is reduced by the return air in addition to being less influenced by the surrounding environment. Can have a stable effect. The return duct 25 surrounds the outer periphery of the precision area 22 and the rectifying box 27 like a jacket, and also surrounds the outer periphery of the supply duct 24 opened to the rectifying box 27.

  The air conditioner 23 includes a blower 32 connected to the supply duct 24, a cooling coil 33, a heating coil 34, a temperature fluctuation absorbing unit 35, and the like, and is covered with a return duct 25 that surrounds the outside in a jacket shape. The return duct 25 is provided with an outside air inlet 36. In the example shown in the figure, a cooling coil 33 and a heating coil 34 are arranged in a row on the supply duct 24 connected to the discharge port side of the blower 32, and a plurality of temperature fluctuation absorption units 35 are provided in the subsequent duct 24a from the upstream side of the flow of the duct 24a ( In the illustrated example, three groups 35a, 35b, 35c) are accommodated in series. This is because the temperature fluctuation absorbing unit 35 stabilizes the outlet temperature to the average temperature of the fluctuation when the temperature on the primary side of the temperature fluctuation absorbing unit 35 fluctuates. The outline will be described with reference to FIG.

  The temperature fluctuation absorption unit 35 provided in the supply duct 24a is provided with an electric heater 351 across the supply duct 24a. The electric heater 351 has a nichrome wire protection pipe 352, and the nichrome wire protection pipe 352 is connected to a temperature sensor 354 provided at a predetermined position of the supply duct 24a via a controller 353. The heater 351 is repeatedly turned on and off by the controller 353 based on the detection value of the temperature sensor 354 so as to keep the temperature sensor 354 at a predetermined temperature. The number of on / off operations is actually 50 or more per second, and the temperature is controlled with high accuracy.

  However, even in the above heat exchange, a lot of heat is transmitted to the air passing in the vicinity of the nichrome wire protection pipe 352, but the heat is not easily transferred to the air passing through a distant position. For this reason, temperature unevenness occurs in the direction crossing the air flow, and this is the main cause of temperature fluctuation. In order to prevent this, in this embodiment, the temperature difference is made by providing three temperature fluctuation absorption units 35. However, as a means for preventing other temperature fluctuations, a substance having a large heat capacity (the larger the weight and specific heat, Absorption).

  The supply duct 24 a is connected to the supply duct 24 connected to the precision temperature area 22. The cooling coil 33, the heating coil 34, the temperature fluctuation absorbing unit 35 of the air conditioner 23, and the outer peripheral portions of the supply ducts 24, 24a connecting them constitute a return duct 25, which is connected to the end of the return duct 25 and connected to the blower 32. And an exhaust port of the blower 32 is connected to the supply duct 24.

Next, the operation of the device of the present invention will be described.
The supply air 37 sucked into the blower 32 from the end portion of the return duct 25 together with the air sucked from the outside air intake 36 as the blower 32 rotates is adjusted to a predetermined temperature by the cooling coil 33 and the heating coil 34, and a plurality of The temperature adjustment is performed more precisely by the temperature fluctuation absorbing unit 35. That is, as an example, the temperature fluctuation width of the airflow is 0.099 ° C. at the point (A) on the entry side of the first temperature fluctuation absorption unit 35a at the most upstream position of the supply duct 24a in FIG. However, at the point (b) immediately after passing through the first temperature fluctuation absorption unit 35a, the temperature fluctuation range is 0.045 ° C., and at the point (c) immediately after passing through the second temperature fluctuation absorption unit 35b, the temperature fluctuation range. Is 0.015 ° C., and the temperature fluctuation width is 0.005 ° C. immediately after passing through the third temperature fluctuation absorption unit 35c, and the precision temperature area 22 passes from the air conditioner 23 through the rectification box 27 by the supply duct 24. Is blown out. The return air from the precision temperature area 22 enters the return duct case 25a from the suction openings 30 and 30, flows into the return duct 25, returns to the blower 32 in the return duct 25, and repeats this.
The return duct case 25a is provided in a jacket shape so as to surround the outer periphery of the precision temperature area 22 and the rectifying box 27, and the supply air at the end of the supply duct 24 is supplied by the return air having a stable temperature returned from the precision temperature area 22. The air is surrounded, and the conditioned air introduced into the precision temperature area 22 is sent to the precision temperature area 22 in a state where it is not influenced by the surrounding environment by the return air.
In the air conditioner 23, the return duct 25 surrounds the outside of the supply duct 24 and is provided in a jacket shape. Therefore, fluctuations in the temperature of the air flow sent through the supply duct that must maintain a predetermined temperature are observed from the outside. Since protection is performed at a temperature close to the predetermined temperature, temperature control can be performed with power saving and precision.

  The present invention is used for business conditions that are extremely strict in setting a temperature environment and that require precise stabilization of the temperature environment as an essential work environment requirement.

The schematic front view of this invention air-conditioning system. Structure explanatory drawing of a temperature fluctuation unit. The schematic front view of the conventional air conditioning system.

Explanation of symbols

1 room 2 primary air conditioning area 3 refrigerator 4 cooling coil 5 heater 6 fan 7 primary air conditioner 8 supply duct 9 outlet 10 wall body 11 precision air conditioning area 12 refrigerator 13 cooling coil 14 heater 15 blower 16 secondary air conditioner 17 duct 18 Hepa Filter 20 Air Conditioning System 21 Housing 22 Precision Temperature Area 23 Air Conditioner 24 Supply Duct 25 Return Duct 25a Return Duct Case 26 Duct 27 Rectification Box 28 Hepa Filter 29 Heat Insulation Material 30 Suction Opening 31 Door 32 Blower 33 Cooling Coil 34 Heating Coil 35, 35a, 35b, 35c Temperature fluctuation absorption unit 36 Outside air intake 37 Supply air 351 Electric heater 352 Nichrome wire protection pipe 353 Controller 354 Temperature sensor

Claims (1)

Equipment for heating and cooling, etc., for precisely adjusting the temperature with an air blower, cooling coil, heating coil and air conditioner having a plurality of temperature fluctuation absorption units connected to the supply duct and sending the conditioned air to the precision temperature area The air supply duct is arranged inside the two-layer structure, and the equipment arranged inside and the outside of the air supply duct is used as a return duct to the air conditioner for returning the return air from the precision temperature area to the air conditioner. An air conditioning system for precisely controlling the temperature of a local space, characterized in that a return air duct case that blows conditioned air into an area and surrounds the most downstream portion of the conditioned air supply duct and continues to the return duct is provided.

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