Air conditioning system of clean room

Abstract

To provide an air conditioning system of a clean room which can preferably realize a clean room at low costs while achieving space saving.SOLUTION: An air conditioning system of a clean room includes: a supply port 10a which supplies conditioned air to an object space S; a blower unit 2 which is provided below the supply port 10a in the object space S, induces air supplied from the supply port 10a, and purifies and sends the air downward; a suction port 10b provided above the floor 13 of the object space S; a duct 20 connecting the supply port 10a with suction port 10b; and an air conditioner 21 provided in the middle of the duct 20. The clean room is configured so that the air sent from the blower unit 2 flows along the floor 13 of the object space S, moves up, and is suctioned into the suction port 10b.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an air conditioning system for a clean room. [Background technology]

[0002] Figure 10 shows an example of an air conditioning system in a clean room. The target space S is configured as a ballroom-style industrial clean room, and multiple air blowing units 2 are installed on the ceiling 1. The air blowing units 2 suck air above the ceiling 1 into a housing using a fan, blow the air against a filter, and send the purified air that has passed through the filter to the target space S below.

[0003] The floor 3 of the target space S is constructed as a raised floor made of materials such as punching panels and gratings. The air sent from the blower unit 2 to the target space S passes through the openings in the floor 3 to the space under the floor, is sent to the space above the ceiling through the return shaft 4 that connects the space under the floor with the ceiling, and is then supplied to the target space S from the blower unit 2 again.

[0004] Equipment 5 such as production equipment is in operation within the target space S, and the indoor air becomes heated as it receives heat generated by the equipment 5, and is then released under the floor as return air. The heated return air must be cooled to a temperature suitable for the operation of the equipment 5 before returning from under the floor to the ceiling space and being sent out again by the blower unit 2. In the example shown here, a cooling unit 6, which is a dry coil, is provided near the entrance to the return shaft 4, and is configured to cool the return air after it has passed through the floor 3 of the target space S.

[0005] 10, clean air is supplied to the target space S from the blower unit 2, while air is circulated throughout the entire facility including the target space S. In this type of air circulation, the blower unit 2 sends air generally downward into the target space S, but the airflow formed by this is not a unidirectional push-out flow, but a non-unidirectional airflow that dilutes and mixes dust generated in the room with the clean air.

[0006] It should be noted that the example shown here is a schematic diagram, and in an actual industrial clean room, in addition to the equipment shown in the diagram, further equipment such as an outdoor air conditioner and a humidifier are usually installed, but these are not shown here.

[0007] Prior art documents relating to this type of clean room air conditioning system include, for example, Patent Document 1 below. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2008-128618 A Summary of the Invention [Problem to be solved by the invention]

[0009] Incidentally, in the conventional clean rooms as described above, a space partitioned off from the target space S is necessary around the target space S for the purposes of air circulation, maintenance, etc. In particular, above the ceiling 1 (attic), on which the numerous blower units 2 are installed, a space with a certain degree of planar area and height must be provided in order to ensure air flow to the blower units 2 and to enable maintenance of the blower units 2.

[0010] Furthermore, in order to widely supply the above-mentioned non-unidirectional airflow to the target space S, it is necessary to construct a wide-area ceiling 1 as a cell ceiling and place the blower units 2 therein. Depending on the configuration of the clean room, the blower units may be sparsely placed on the ceiling, but even in such cases, it is still necessary to construct a wide-area ceiling using the blower units and blank panels in order to place the blower units at regular intervals.

[0011] Furthermore, negative pressure is generated in the space above the ceiling as the blower unit 2 operates. In the case of an industrial clean room, a balance damper (not shown) is used to create a slight positive pressure in the target space S relative to atmospheric pressure, which further increases the pressure difference with the space above the ceiling. For this reason, a mechanism is required on the building structure to prevent dust from entering the space above the ceiling from the outside. Thus, the installation of a wide ceiling and space above the ceiling is a factor in increasing the cost of constructing the target space S as a clean room.

[0012] In view of the above circumstances, the present invention aims to provide an air conditioning system for a clean room that can maintain a sufficient level of cleanliness in the target space while reducing the area required for the installation surface of the air blowing unit. [Means for solving the problem]

[0013] The present invention relates to an air conditioning system for a clean room comprising a supply port which supplies conditioned air to a target space, a blower unit which is provided in a position within the target space below the supply port and which draws in the air supplied from the supply port, purifies it, and sends it out downwards, an intake port which is provided above the floor of the target space, a duct which connects the supply port and the intake port, and an air conditioner provided midway through the duct, and which is configured so that the air sent out from the blower unit flows along the floor of the target space, then rises and is sucked into the intake port.

[0014] In the air conditioning system for a clean room of the present invention, a blower section having the blower unit arranged on a lower ceiling installed below the upper ceiling may be provided in a portion of the target space, and the supply port may be provided above the blower section.

[0015] In the air conditioning system for a clean room of the present invention, the suction port may be provided in the upper ceiling. Effect of the Invention

[0016] According to the air conditioning system for a clean room of the present invention, it is possible to reduce the area required for the installation surface of the air blowing unit while maintaining a sufficient degree of cleanliness in the target space. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic elevational view showing an example (first embodiment) of an air conditioning system for a clean room according to the present invention; [Diagram 2] FIG. 2 is a schematic plan view of the air conditioning system of FIG. [Diagram 3] FIG. 4 is a schematic elevational view showing another example (second embodiment) of an air conditioning system for a clean room according to the present invention. [Figure 4] FIG. 4 is a schematic plan view of the air conditioning system of FIG. [Diagram 5] FIG. 11 is a schematic elevational view showing still another example (third embodiment) of the configuration of the air conditioning system for a clean room according to the present invention. [Figure 6] FIG. 6 is a schematic plan view of the air conditioning system of FIG. 5. [Figure 7] 1A and 1B show the results of simulating the air flow and conditions in a clean room air conditioning system, where (A) shows the air flow velocity distribution in a reference example of the present invention, and (B) shows the air flow velocity distribution in an embodiment of the present invention. [Figure 8] 1A and 1B show the results of simulating the air flow and conditions in a clean room air conditioning system, where (A) shows the air temperature distribution in a reference example of the present invention, and (B) shows the air temperature distribution in an embodiment of the present invention. [Figure 9] FIG. 1 shows the results of simulating the air flow and conditions in an air conditioning system for a clean room, where (A) shows the distribution of air age in a reference example of the present invention, and (B) shows the distribution of air age in an embodiment of the present invention. [Figure 10] FIG. 1 is a schematic elevational view showing an example of a conventional air conditioning system for a clean room. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0019] 1 and 2 show an example (first embodiment) of an air conditioning system for a clean room according to the present invention, and in the figures, parts that are given the same reference numerals as those in FIG. 10 represent the same things.

[0020] In this first embodiment, the blower section 8 equipped with the blower unit 2 is installed in the wall area of ​​the target space S. In the example shown here, a part of the area in plan view (the wall area) has a double ceiling structure in which the ceiling 11 is suspended below the ceiling 10 installed along the structure of the building frame, and the blower section 8 is configured by installing the blower unit 2 on the ceiling 11 (for convenience, the ceiling 11 on which the blower unit 2 is arranged will be referred to as the "lower ceiling" and the ceiling 10 located above the lower ceiling 11 will be referred to as the "upper ceiling" as necessary). In the conventional example shown in FIG. 10, the entire ceiling except the installation area of ​​the return shaft 4 in the plan view of the target space S was configured as a double ceiling, but in this first embodiment, the lower ceiling 11 is installed as a lowered ceiling only in a part, and only that area is a double ceiling. In the area where this double ceiling is formed, a space is formed which is sandwiched above and below by an upper ceiling 10 and a lower ceiling 11, and in some places has a wall 7 located on the side. The conditioned air supplied from the supply port 10a temporarily stays in this space, and is then mixed with the air located in the upper layer of the target space S before being sent out from the blower unit 2.

[0021] The blower unit 2 installed on the lower ceiling 11 is a device known as a fan filter unit (FFU) or the like that has a fan and a filter (e.g. a HEPA filter or ULPA filter) in a housing. The fan draws air above the lower ceiling 11 into the housing and blows it onto the filter, and then sends the purified air downward into the target space S below.

[0022] Further, a hanging wall 9 is provided on the lower ceiling 11 so as to extend downward from the vicinity of the air outlet of the blower unit 2, and is adapted to adjust the direction of the air blown out from the blower unit 2 as described later.

[0023] In this specification, expressions such as "downward" and "sideways" are used in relation to air flow, etc., but these do not only refer to directions that exactly match the vertical or horizontal directions, but also refer to directions that can be generally considered to be "downward" or "sideways" in the normal sense, or in an air conditioning system such as the present invention. Furthermore, an expression such as "along the floor" does not only refer to a direction that exactly matches the surface of the floor, but also means that the direction is generally along the surface of the floor. Similarly, the expression "orthogonal" does not only mean that one direction and another direction form an exact right angle, but refers to an angle that can be practically expressed as "orthogonal."

[0024] A supply port 10a that supplies conditioned air to the room is provided in the upper ceiling 10 above the area where the blower 8 is provided. Also, an intake port 10b that draws in air from the room is provided in an appropriate position in the upper ceiling 10 in an area far from the blower 8. The arrangement of the supply port 10a and the intake port 10b will be described in detail later.

[0025] A duct 20 is provided on the upper side of the upper ceiling 10, forming an air flow path connecting the intake port 10b and the supply port 10a, and an air conditioner 21 is provided in the middle of the duct 20. Here, the duct 20 is illustrated in an area outside the target space S above the upper ceiling 10, but the duct 20 may be appropriately positioned as long as it appropriately connects the intake port 10b and the supply port 10a. For example, the duct 20 may be disposed on the lower side of the upper ceiling 10. The air conditioner 21 includes a cooling unit 21a and a fan 21b inside, and draws in air from the target space S through the duct 20 by operating the fan 21b, adjusts the temperature with the cooling unit 21a, and supplies the air as conditioned air through the supply port 10a. The cooling unit 21a is, for example, a coil through which a refrigerant flows, and is configured to draw in the refrigerant from an external heat source device 22, exchange heat with the air flowing outside the coil, and then return the refrigerant to the heat source device 22. Note that, although an air conditioner equipped with a cooling unit 21a has been exemplified as the air conditioner 21 here, the type of air conditioner that can be used in the air conditioning system of the present invention is not limited to this, and may be, for example, a PAC (packaged air conditioner) or a direct expansion type air conditioner, etc.

[0026] The floor 13 of the target space is not configured as a punching panel or grating, unlike the floor 3 in the conventional example shown in FIG. 10. The floor 13 in this first embodiment is a structure in which the entire surface is closed in principle, and the space under the floor is not assumed to be an air passage, and the air flows only above the floor 13 as described later (although it is possible to provide holes or the like for passing some member such as a cable in a part of the floor as necessary, so long as it does not interfere with the flow of air). In addition, the floor 13 may be made a raised floor as necessary, and the space under the floor may be used as a power usage space, but it is not necessary to have a height that allows air to flow as in the conventional example in FIG. 10 (FIG. 1 shows an example in which the floor 13 is slightly raised, assuming that the space under the floor is used as a power usage space). On the upper surface of the floor 13, equipment 5 such as production equipment is placed and operates.

[0027] The following describes the setting of the area where the blower section 8 is provided, and the arrangement of the supply port 10a, the intake port 10b, and the hanging wall 9. In this first embodiment, as shown in Fig. 2, the lower ceiling 11 is provided in two elongated rows along the walls 7 at both ends of the room which is generally rectangular in plan view. Two rows of blower units 2 are provided linearly along the longitudinal direction of the lower ceiling 11, forming two blower sections 8 along the walls.

[0028] Supply port 10a is provided in an area of ​​upper ceiling 10 where blower section 8 is installed in plan view, and is particularly installed at a position close to blower unit 2 arranged on lower ceiling 11. The installation position of supply port 10a may be, for example, directly above blower unit 2, or may be at a position some distance from directly above. The specific range over which supply port 10a should be located varies depending on the distance between supply port 10a and blower unit 2 and the blown air volume of both, but should be a distance that allows the main flow of air supplied from supply port 10a to be suitably guided to blower unit 2, as described below.

[0029] Meanwhile, intake port 10b is provided in a position on upper ceiling 10 away from supply port 10a and blower unit 2. In the case of this first embodiment, blower sections 8 are provided along two opposing walls 7 among the walls 7 that form the four sides of target space S in a plan view, blower unit 2 and supply port 10a are disposed in and near blower section 8, and intake port 10b is provided in a position on upper ceiling 10 that is midway between blower sections 8 provided on both sides of target space S (the middle part in the left-right direction in Figs. 1 and 2).

[0030] The position of the intake port 10b should be "the side to which air is to be guided in a plan view as seen from the blower unit 2" and "the position in the desired direction as seen from the blower unit 2" from the viewpoint of air flow, which will be described later. In this first embodiment, as will be described later, air sent out from the blower units 2 arranged along the walls 7 on both sides is guided to the center of the room on the floor 13. The intake port 10b is provided at that position (the central area of ​​the target space S to which the air is guided). In other words, the device 5 to which the conditioned air is to be supplied is installed on the floor 13 in the area between the blower section 8 (the supply port 10a and the blower unit 2 outlet) and the intake port 10b in a plan view.

[0031] The hanging wall 9 is provided on the underside of the lower ceiling 11 on which the blower unit 2 is installed, so as to extend downward from the vicinity of the blower unit 2's outlet. In the case of the first embodiment, in a plan view, it is provided on the same side as the inlet 10b as seen from the blower unit 2, that is, in the direction for guiding air as seen from the blower unit 2, on the opposite side to the wall 7 near the blower unit 2, so as to form a surface parallel to the wall 7. The arrangement of the hanging wall 9 is not limited to the example shown here, and may be changed as appropriate as long as the air flow described below can be realized without any hindrance. For example, it may be provided so as to surround the blower unit 2 in a plan view. Alternatively, in some cases (when the air flow is not hindered even without the hanging wall), the hanging wall may be omitted.

[0032] The flow of air in the first embodiment will be described. As shown in FIG. 1, clean air is sent downward from the blower unit 2 provided in the blower section 8 at the wall toward the floor 13 of the target space S. The downward air collides with the floor 13 and changes its flow direction along the surface of the floor 13. In the case of the first embodiment, the wall 7 is located in one of the four horizontal directions for the air sent out from the blower unit 2, and in the other two directions, there is a downward flow of air sent out from another adjacent blower unit 2. Most of the air sent out downward from the blower unit 2 and changed its direction along the floor 13 is blocked by these in three directions and is guided to the remaining direction, which is the desired direction (note that, with regard to the air sent out from the blower units 2 located at both ends of the blower units 2 arranged in a line, the walls 7 are located in two directions and there is a flow of air sent out from the adjacent blower unit 2 in one direction, so as a result, it similarly flows in the remaining direction). Here, the "target direction" refers to the direction of the area to which air is desired to be supplied as viewed from the blower unit 2, and in the case of a clean room such as the first embodiment, the direction of the area in which the equipment 5 is arranged. In terms of the drawing, it is the right for the blower units 2 arranged in the left row in the drawing, and the left for the blower units 2 arranged in the right row. Also, suction port 10b is located in upper ceiling 10 at a position that corresponds to the target direction as viewed from blower unit 2 in a plan view.

[0033] The air that has been redirected in this way moves toward the center of the target space S in which the equipment 5 is placed. At this time, the main flow of the air crawls along the upper surface of the floor 13 due to the Coanda effect, while receiving heat from the equipment 5. Some of the air, whose temperature has risen as a result, moves upward due to density differences caused by the temperature difference, and a temperature stratification is formed on the floor 13 where the higher the position, the higher the temperature, and the lower the position, the lower the temperature.

[0034] In this first embodiment, the air blowing units 2 are provided along the walls 7 on both sides of the room in a plan view, and the above-mentioned air movement occurs for each of the air blowing units 2 on both sides. The air flow along the floor 13 flows from positions along the walls 7 on both sides of the target space S to the opposite side of the walls 7 (the direction in which the intake port 10b is located as viewed from the air blowing units 2), so that as viewed from the floor 13, air flows are formed from both ends of the target space S toward the center.

[0035] The main streams of air flowing along the floor 13 from both ends of the target space S collide with each other in the center, where they begin to rise. Above the flow of the rising air is an intake port 10b located in the upper ceiling 10, and air is sucked in through this intake port 10b.

[0036] The air sucked in from the intake port 10b passes through the duct 20, is cooled by the cooling unit 21a of the air conditioner 21, and is supplied as conditioned air from the supply port 10a to the target space S. Since the blower unit 2 is disposed in a position adjacent to and below the supply port 10a, the conditioned air supplied from the supply port 10a is drawn into the blower unit 2 by the operation of the fan in the blower unit 2. At this time, the conditioned air supplied from the supply port 10a is retained in the space sandwiched above and below by the upper ceiling 10 and the lower ceiling 11, and is drawn into the blower unit 2 while mixing with the air located in the upper layer of the target space S. The drawn air is purified by passing through the filter of the blower unit 2, and is sent again below the blower section 8 as clean air.

[0037] Here, as described above, the hanging wall 9 is provided near the blower unit 2 on the underside of the lower ceiling 11 constituting the blower section 8. If the hanging wall 9 were not provided, some of the air sent out from the blower unit 2 would be drawn into this air flow, and a short circuit may occur in which the air immediately after being sent out from the blower unit 2 is drawn back into the blower unit 2 before reaching the floor 13. Such a short circuit is a wasteful movement from the viewpoint of supplying air in an appropriate state to the target area (in this case, the area around the equipment 5), and is energy inefficient.

[0038] Therefore, if a hanging wall 9 is provided near the air outlet of the blower unit 2 (in this first embodiment, at a position opposite to the nearby wall 7 as viewed from the blower unit 2), the air flow sent downward from the blower unit 2 is prevented from mixing with the air flow ascending in the area near the blower section 8 in a plan view, thereby preventing the occurrence of a short circuit. In particular, in the case of this first embodiment, as described above, three directions from the air blown out from the blower unit 2 are blocked by the wall 7 and other air flows, and the air flow is guided in the remaining one direction along the floor 13, but here the hanging wall 9 is provided at a position corresponding to that one direction (the direction in which the air is guided) as viewed from the air outlet of the blower unit 2 in a plan view. This makes it possible to efficiently prevent the occurrence of a short circuit in the direction in which the air is guided.

[0039] Thus, in the air conditioning system of this first embodiment, as shown in Figure 1, the air sent downward from the blower unit 2 installed at the end of the target space S flows along the upper surface of the floor 13, collides with each other in the center, rises, is sucked into the duct 20 through the intake port 10b, sent out through the supply port 10a, is attracted to the blower unit 2, and is sent downward again from the blower unit 2, forming an air circulation pattern.

[0040] In addition, the air sent out from the blower unit 2 and flowing along the floor 13 receives heat from the equipment 5 and rises in temperature while traveling over the floor 13. A portion of the heated air rises to a height near the upper ceiling 10 before reaching the position of the suction port 10b in a plan view. The air at a height near the upper ceiling 10 is sucked in through the suction port 10b. Here, it is conceivable that some of the air will not reach the position of the suction port 10b, but will be attracted toward the blower unit 2 and sent downward from the blower unit 2; however, in the case of the first embodiment, such air movement is slight, even if it occurs at all. In this first embodiment, the air sent out from the blower unit 2 is efficiently guided to the position of the suction port 10b by being sucked in at the suction port 10b, and further, the heated air rises relative to the cold air sent out from the blower unit 2 and flowing along the floor 13, forming a temperature stratification, and it is considered that the two do not easily mix (the cold air located below passes through the layer of warm air located above and is guided to the blower unit 2).

[0041] It should be noted that the example shown here is a schematic diagram, and in an actual industrial clean room, in addition to what is shown in the diagram, various other facilities such as outdoor air conditioners, humidifiers, and rails and transport vehicles for transporting products are usually installed as necessary. However, such configurations that are not directly related to the gist of the present invention have been omitted from the illustration here as appropriate.

[0042] An air conditioning system such as the first embodiment shown in Fig. 1 and Fig. 2 is advantageous in terms of space utilization efficiency compared to the conventional example shown in Fig. 10. In the conventional example of Fig. 10, in order to widely supply downflow to the target space S, a wide-area ceiling 1 is constructed as a cell ceiling, a blower unit 2 is placed there, and the entire space above the ceiling (the space above the ceiling 1) is used as the air flow path. In contrast, in the first embodiment shown in Fig. 1 and Fig. 2, a duct 20 is provided as the air flow path instead of the space above the ceiling, and indoor air is sucked in from the intake port 10b and supplied from the supply port 10a near the blower unit 2. In other words, since the duct 20 is used as the return air flow path, there is no need to install a large space such as the space above the ceiling in Fig. 10.

[0043] In the conventional example of FIG. 10, the entire ceiling 1 is used as the installation surface for the blower unit 2, but in this first embodiment, the area where the blower unit 2 is installed is limited to both sides of the room, and only these areas need to be double-ceilinged, and the lower ceiling 11 is not required in other areas. In the area where the lower ceiling 11 is not provided, the height up to the upper ceiling 10 can be used, so more space can be used as a clean room compared to the example of FIG. 10, and it is easy to arrange, for example, tall devices and equipment. In this first embodiment, although it is necessary to secure a certain area of ​​the lower ceiling 11 near the blower unit 2 for maintenance and the like, the area of ​​the area where the height direction of the space can be effectively used can be significantly wider compared to the conventional example shown in FIG. 10.

[0044] 10, the space under the floor was used as an air flow path, so a certain amount of height was required for the space under the floor, but in this first embodiment, air flows above the floor 13, so from the perspective of air circulation, the floor 13 does not need to be a raised floor, and even if it is a raised floor, it does not need to be very high. In other words, with regard to the floor as well, this first embodiment makes effective use of the height of the space, and a large space can be secured that can be used as a clean room. Also, since air is not circulated under the floor, no measures are required to maintain high air cleanliness there.

[0045] Furthermore, temperature stratification is formed within the target space S, and the heated air rises due to density differences and is sucked in through the intake port 10b or attracted to the blower unit 2, so there is no need for a structure such as a return shaft to send return air from under the floor to the space between the floor and the ceiling, making more effective use of the area of ​​the space.

[0046] Furthermore, the first embodiment utilizes temperature stratification to efficiently cool the target space S that requires air conditioning, particularly at a height close to the floor 13, and is therefore advantageous in terms of air conditioning efficiency. In the conventional example shown in Fig. 10, conditioned air is supplied downward to almost the entire area of ​​the target space S in a plan view, and receives heat generated by the equipment 5 to raise the temperature. For this reason, it was necessary to adjust the temperature of the entire area below the ceiling 1 where the blower unit 2 is installed to an appropriate level, but in the case of the first embodiment, relatively low-temperature air can be efficiently sent to the height near the floor 13 where the equipment 5 is installed by using temperature stratification, so less energy is required for cooling. In the conventional example, it was necessary to set the blowing temperature low in anticipation of a rise in temperature due to the heat of the equipment 5. However, in the case of this first embodiment, the air that has been heated by absorbing the heat from the equipment 5 does not mix much with the low-temperature air sent out from the blowing unit 2, and the equipment 5 to be cooled can be cooled with air at a temperature close to the blowing temperature from the blowing unit 2. Therefore, the blowing temperature of the blowing unit 2 (the outlet temperature of the cooling unit 21a of the air conditioner 21) can be set high.

[0047] In addition, in this first embodiment, a heat pool is formed near the upper ceiling 10 due to temperature stratification, and an intake port 10b is provided at the height of the upper ceiling 10 to recover the air from the heat pool as return air for the air conditioner 21. Compared to a case where an intake port is provided on the floor 13, for example, it is possible to cool high-temperature air, so that cooling in the air conditioner 21 can be performed under conditions of high energy efficiency.

[0048] In the case of this first embodiment, air is driven by being sucked in through suction port 10b provided at an appropriate position on upper ceiling 10 (in the desired direction as viewed from blower unit 2), and this allows the air to reach a position far from blower unit 2. The movement of air blown out from blower unit 2 is, of course, primarily driven by the operation of blower unit 2, but in this first embodiment, suction port 10b is provided at a position to which it is desired to guide the air as viewed from blower unit 2, and air is sucked in from here, thereby driving the air not only at the original position from which the air is supplied (blower unit 2) but also at a position beyond that (suction port 10b).

[0049] In addition, in this first embodiment, the Coanda effect is effectively utilized for the transport of air supplied from the blower unit 2. The air supplied from the blower unit 2 to the target space S is first sent downward and collides with the floor 13. The colliding air is redirected along the upper surface of the floor 13, and thereafter reaches a long distance from the blower unit 2 due to the Coanda effect, and clean air can be efficiently delivered to devices other than the device 5 located directly below the blower unit 2. This can fully achieve a cleanliness level of, for example, around class 6. The flow of air in the target space S will be described in detail later.

[0050] In addition, in the case of the first embodiment, the cooling unit is not installed in the target space S, but the air sucked from the target space S is guided to the external air conditioner 21 and cooled there, so there is no need to worry about condensation compared to the conventional example of FIG. 10 in which the cooling unit 6 is installed in the target space S. In general, the occurrence of condensation is undesirable in a clean room where semiconductors and the like are handled, and therefore, when a cooling unit is installed in the target space, it is necessary to design it as a dry coil. However, if the air is cooled by the air conditioner 21 installed outside the target space S as in the first embodiment, condensation in the target space S can be more reliably prevented. In addition to condensation, when water is used as a heat medium for the cooling unit, it is necessary to pay attention to water leakage from the piping that constitutes the cooling unit and its surroundings. Depending on the arrangement and configuration of the air conditioning equipment in the clean room, the cooling unit may be installed above the equipment such as production equipment, and in that case, measures against condensation and water leakage are particularly important. For this reason, for example, it is necessary to install a sensor that detects water leakage. If the cooling unit 21a is disposed outside as in the first embodiment, even if condensation or water leakage occurs, it is possible to effectively prevent this from affecting the operation of the equipment.

[0051] Furthermore, when the cooling unit 6 is installed within the target space S as in the conventional example shown in FIG. 10, the refrigerant is drawn from an external heat source to the cooling unit 6 inside the room, which complicates the design of the air conditioning equipment. However, when air is sent outside the target space S for cooling as in this first embodiment, a packaged air conditioner can be used as the air conditioner 21, and in that case, the cost associated with installing the air conditioning equipment can be reduced.

[0052] In the first embodiment, no particular wall-like structure is provided to separate the area in the target space S where the blower 8 is provided from the other areas, but for example, a side wall that forms a surface along the vertical direction between the upper ceiling 10 and the edge of the lower ceiling 11 may be provided to separate the area in which the blower 8 is provided from the other areas in the target space S (not shown). In this case, the air supplied from the supply port 10a is first supplied to the area separated by the side wall, and then sent out onto the floor 13 in the target space S through the blower unit 2. When such a side wall is provided, the side wall may be provided with an air vent as necessary.

[0053] Here, when such a side wall (not shown) is not provided as in the first embodiment, there is a concern that the air supplied from the supply port 10a will not pass through the blower unit 2 and will circulate in the target space S in an unpurified state (high air age state) depending on the arrangement of the supply port 10a relative to the blower unit 2 and the relationship between the air volume of the blower unit 2 and the air volume supplied from the supply port 10a. However, if the distance between the blower unit 2 and the supply port 10a is sufficiently short and the air volume of the blower unit 2 is equal to or greater than the air volume of the supply port 10a, it can be considered that almost the entire amount of air supplied from the supply port 10a passes through the blower unit 2, and no problem occurs in maintaining cleanliness.

[0054] 3 and 4 show another example (second embodiment) of the arrangement of the devices in the air conditioning system according to the present invention (note that in FIG. 3, the air conditioner 21 and the heat source device 22 in FIG. 1 are omitted. The same applies to FIG. 5 described later). In the first embodiment shown in FIGS. 1 and 2, the blower section 8 with the blower unit 2 arranged on the lower ceiling 11 is provided along the opposing walls 7 of a room that is generally rectangular in plan view, and air is sent from both ends of the room toward the center. In the second embodiment, the blower section 8 is provided along the wall 7 that forms one side of the room, and air is sent from there toward the opposite wall 7 where the blower section 8 is not installed. An intake port 10b is located in the upper ceiling 10 near the wall 7 opposite to the wall 7 on which the blower section 8 is provided.

[0055] When the blower 8 is disposed in this manner, the air sent downward from the blower unit 2 collides with the floor 13, and is blocked in three directions by the wall 7 located in one horizontal direction and the downward air flow in two directions (or the wall 7 located in two directions and the downward air flow in one direction), as in the first embodiment shown in Figs. 1 and 2, and is guided in the remaining direction, which is the desired direction (the direction in which the wall 7 on the opposite side as viewed from the blower unit 2 is located, and the direction in which the suction port 10b is provided in the upper ceiling 10). Meanwhile, in the area near the wall 7 on the opposite side where the blower unit 8 is not disposed, the air flow sent from the blower unit 2 side and moving along the floor 13 collides with the wall 7 and starts to rise. Also, part of the air moving in the desired direction along the floor 13 receives heat from the equipment 5 located along the way and rises, and merges with the air flow guided along the floor and wall above the floor 13. The rising air is sucked in through the intake port 10b of the upper ceiling 10 or drawn into the blower unit 2. In this way, as shown in Fig. 3, an air circulation is formed that is roughly half the air flow in the first embodiment (see Fig. 1), and the target space S, which is a clean room, is realized in the same way as in the first embodiment.

[0056] 5 and 6 show yet another example (third embodiment) of the device arrangement of an air conditioning system according to the present invention. In this third embodiment, a total of two rows of blowers 8 are arranged along opposing walls 7 in a room that is generally rectangular in plan view, similar to the first embodiment, but in addition, a third row of blowers 8 is provided in the central area of ​​the room.

[0057] This third row of blower units 8 is arranged parallel to the first and second rows of blower units 8 located at both ends of the room, and its position is closer to the second row than the center in the direction perpendicular to the arrangement of the first and second rows of blower units 2, if the left side blower unit 8 in Figures 5 and 6 is the first row and the right side blower unit 8 is the second row.

[0058] In the upper ceiling 10, an intake port 10b is provided at a position midway between the first and third rows of blowers 8 in a plan view. In addition, an intake port 10b is also provided at a position to the right of the third row of blowers 8 (closer to the second row of blowers 8) in a plan view.

[0059] The air sent out from the blower unit 2 in the first row (left side) collides with the floor 13, and is blocked in three horizontal directions by the air flows from the wall 7 and the adjacent blower unit 2, and is guided in the remaining desired direction (to the right), just as in the first embodiment shown in Figures 1 and 2. Similarly, the air sent out from the blower unit 2 in the second row (right side) is blocked in three horizontal directions by the air flows from the wall 7 and the adjacent blower unit 2, and is guided in the remaining desired direction (to the left).

[0060] The air sent out from the blower unit 2 in the third row (center) also collides with the floor 13 and changes direction, but in this case, of the four horizontal directions seen from the air flow, in one direction there is a flow of air sent out from the blower unit 2 in the second row and flowing to the left, and in the other direction there is a downward flow of air sent out from the adjacent blower unit 2 in the same third row (with regard to the air sent out from the blower units 2 located at both ends of the third row, there is an air flow flowing from the blower unit 2 in the second row in one direction, and a downward flow of air sent out from the adjacent blower unit 2 in the third row in one direction, and a wall 7 is located in yet another direction). The air flow that changes direction along the floor 13 is blocked by these and is guided to the remaining desired direction (to the left).

[0061] The air flow sent out from the blower units 2 in the first row and moving to the right along the upper surface of the floor 13 and the air flow sent out from the blower units 2 in the third row and moving to the left along the upper surface of the floor 13 collide with each other at a position halfway between the first and third rows and start to rise. The rising air flow is sucked in through the suction port 10b above the floor 13.

[0062] When the air flow sent out from the second row of blower units 2 and moving leftward along the upper surface of floor 13 reaches the vicinity of the third row of blower units 2, there is an air flow sent out downward from the third row of blower units 2 ahead. At this point, the air flow sent out from the second row of blower units 2 changes direction and begins to rise. The rising air flow is sucked in through suction port 10b above floor 13.

[0063] Thus, for the air sent out from the first and third row of blower units 2, a circulation is formed generally similar to that of the first embodiment shown in Figures 1 and 2, and for the air sent out from the second row of blower units 2, a circulation is formed generally similar to that of the second embodiment shown in Figures 3 and 4. As a result, a target space S that is a clean room is realized, similar to the first and second embodiments described above.

[0064] The circulation of air as in each of the above embodiments is achieved by skillfully arranging another air flow or a wall 7 to guide the air flow sent out from the blower unit 2. Specifically, first, the blower units 2 that send air downward are arranged in a line, so that the main direction of the air that is blown against the floor 13 and changed is limited to two directions perpendicular to the direction in which the blower units 2 are arranged. By placing the downward air flows adjacent to each other, the subsequent flow directions are mutually restricted. Furthermore, by further blocking one of the two directions with a wall 7 or another air flow (a downward, sideways, or upward air flow sent out from another blower unit 2), the air flow is guided to the desired direction.

[0065] The air thus sent out reaches a certain distance along the upper surface of the floor 13, where it collides with the wall 7 or another airflow (a downward, sideways, or upward airflow sent out from another blower unit 2) and rises, and is sucked into the suction port 10b provided above the floor 13. By appropriately arranging the wall 7 and the airflow at the position where the air reaches, the airflow is well guided even at the destination where it reaches, and is suitably taken in from the suction port 10b, thereby forming the air circulation as shown in Figures 1, 3, and 5. One of the features of the present invention is that the air is sent out downward from the blower unit 2 to collide with the floor 13, and the airflow reaches a long distance by utilizing the Coanda effect, but at that time, if the downward airflow is simply made to collide with the floor 13, the airflow will dissipate in all directions along the floor 13. Therefore, the airflow is guided by devising the arrangement of the blower unit 2, the wall 7, and the suction port 10b, and the circulation as described above is formed. In addition, the thermal driving effect caused by the heat of the device 5 is also utilized to allow a certain amount of air to reach long distances.

[0066] In this way, by appropriately arranging the blower unit 2, the intake port 10b, the wall 7, etc., it is possible to appropriately guide the air flow in the desired direction with a simple configuration. Furthermore, even in a large-area clean room, by appropriately combining these, it is possible to supply clean air at an appropriate temperature to every corner of the target space. In this case, for example, four or more rows of blower sections 8 consisting of the lower ceiling 11 and the blower unit 2 may be provided. Note that, in addition to the air flow and the wall 7, it is also possible to provide other objects or structures (such as a screen-like object) to guide the air flow or to make it collide and rise.

[0067] Figures 7 to 9 show the results of simulating the air flow and conditions in a clean room to which the present invention is applied as described above. In each figure, (A) is a reference example, and (B) is a simulation of an embodiment to which the present invention is applied. Figure 7 shows the distribution of flow velocity in the front cross section of the space, Figure 8 shows the distribution of air temperature, and Figure 9 shows the distribution of air age. In Figure 7, the direction and magnitude of the air flow velocity at each position are represented by the direction of the arrows and density. In Figures 8 and 9, areas with low air temperature or air age are represented by light colors, and areas with high air temperature or air age are represented by dark colors.

[0068] In the reference example shown in (A) of each figure, a configuration corresponding to the suction port 10b in each embodiment shown in Figs. 1 to 6 is not provided. Instead, an suction port (indicated by the reference symbol 10c in the figure) is provided above the blower unit 2, near the position of the supply port 10a in each embodiment shown in Figs. 1 to 6, so that heated air is sucked in from there. The space from the suction port 10c to the blower unit 2 is separated from other spaces by the lower ceiling 11 and a side wall (indicated by the reference symbol 14), and the suction port 10c is provided in the side wall 14. In addition, a cooling unit 6 is provided at the position of the suction port 10c, so that the air is cooled as it passes through the suction port 10c.

[0069] In each simulation, a condition was set in which no equipment was placed on the floor for both the reference example (A) and the working example (B).

[0070] 7, in the reference example (A), arrows are concentrated around the air outlet of the blower unit 2 on the right side of the target space S and the air inlet 10c above it, and it can be seen that the air sent out from the air outlet of the blower unit 2 rises before it reaches far from the air outlet and is sucked into the air inlet 10c, creating a short circuit (however, arrows are also distributed toward the left end of the space, although not as many as in the right area, and the air is not completely stagnant). On the other hand, in the example (B), horizontal arrows are distributed over the entire area in the left-right direction along the floor 13, and it can be seen that the air flow is appropriately guided from the blower unit 2 on the right end to the air inlet 10b on the left end.

[0071] Next, referring to FIG. 8, it can be seen that in the embodiment of (B), low-temperature air is distributed at the bottom, and high-temperature air is distributed above it, forming a heat pool near the upper ceiling 10. This shows that a favorable temperature stratification is formed by the flow of low-temperature air moving along the floor 13 and the air that rises in temperature and moves upward. In contrast, in the reference example of (A), although low-temperature air is distributed in the leftmost region, the low-temperature air is unevenly distributed in the space from the outlet to the intake 10c of the blower unit 2. The low-temperature air that has just been sent out from the blower unit 2 is sucked in through the intake 10c without having fully absorbed the heat in the target space S.

[0072] The same is true for the age of air shown in Fig. 9. In the example of (B), the young air spreads almost uniformly along the floor 13 from the position of the air outlet of the fan unit 2 on the right side to the position of the air inlet 10b on the left side. On the other hand, in the reference example of (A), air with a particularly young age does not reach the space at the left end. This is thought to be due to the short circuit described above.

[0073] In this manner, in this embodiment, by sucking in air from the intake port 10b arranged in the direction in which air is blown out as viewed from the blower unit 2, the air in the target space S can be efficiently guided far away, thereby achieving suitable air conditioning in the target space S, which is a clean room.

[0074] As described above, the air conditioning system for the clean room of this embodiment includes the supply port 10a that supplies conditioned air to the target space S, the blower unit 2 that is provided below the supply port 10a in the target space S and draws in the air supplied from the supply port 10a, purifies it, and sends it out downward, the inlet port 10b that is provided above the floor 13 of the target space S, the duct 20 that connects the supply port 10a and the inlet port 10b, and the air conditioner 21 that is provided in the middle of the duct 20, and is configured so that the air sent out from the blower unit 2 flows along the floor 13 of the target space S, then rises and is sucked into the inlet port 10b. In this way, the air suction from the inlet port 10b and the Coanda effect with the floor 13 can be used to make the air sent out from the blower unit 2 reach a long distance. In addition, since the duct 20 is used as a return air flow path, there is no need to install a large space such as a space above the ceiling as a return air flow path.

[0075] In the air conditioning system for the clean room of this embodiment, a blower section 8 having a blower unit 2 is provided on a lower ceiling 11 installed below an upper ceiling 10 in a partial area of ​​the target space S, and a supply port 10a is provided above the blower section 8. In this way, a limited area is sufficient as the installation surface for the blower unit 2, making it possible to utilize the space more efficiently.

[0076] In the air conditioning system for the clean room of this embodiment, the air inlet 10b is provided in the upper ceiling 10. In this way, by installing the air inlet 10b for drawing in return air at the height of the upper ceiling 10, high temperature air can be cooled, thereby improving the efficiency of air conditioning.

[0077] Therefore, according to each of the above embodiments, a clean room can be realized in a space-saving and inexpensive manner.

[0078] Incidentally, the air conditioning system for a clean room according to the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention. [Explanation of symbols]

[0079] 2 Blower unit 8 Blower 10 Ceiling (Upper Ceiling) 10a Supply port 10b Intake port 11 Ceiling (lower ceiling) 13 Beds 20 Duct

Claims

1. A supply port for supplying conditioned air to a target space; A blower unit is provided below the supply port in the target space, and draws in air supplied from the supply port, purifies the air, and sends it out downward; An intake port provided above the floor of the target space; A duct connecting the supply port and the suction port; An air conditioner provided midway through the duct; Equipped with The air sent out from the blower unit flows along the floor of the target space, then rises and is sucked into the suction port. A clean room air conditioning system characterized by:

2. A blower unit having the blower unit is provided in a lower ceiling installed below the upper ceiling in a partial area of ​​the target space, The supply port is provided at a position above the blower.

2. The air conditioning system for a clean room according to claim 1 .

3. The suction port is provided in the upper ceiling.

3. The air conditioning system for a clean room according to claim 2.

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