JP7531999B1 - Clean room air conditioning system - Google Patents

Abstract

[Problem] To provide an air conditioning system for a clean room that can realize a clean room in a space-saving and inexpensive manner. [Solution] The clean room is configured with a supply port 10a that supplies conditioned air to a target space S, a 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, an intake port 10b provided above a floor 13 of the target space S, a duct 20 that connects the supply port 10a and the intake port 10b, and an air conditioner 21 provided midway through the duct 20, and 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 intake port 10b. [Selected Figure] Figure 1

Description

The present invention relates to an air conditioning system for a clean room.

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 and blow it onto a filter, and then send the purified air that passes through the filter into the target space S below.

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

In the target space S, equipment 5 such as production equipment is in operation, and the indoor air receives heat generated by the equipment 5, becomes heated, and is released under the floor as return air. The heated return air needs to 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 of the return shaft 4, and is designed to cool the return air after it has passed through the floor 3 of the target space S.

Thus, in the air conditioning system shown in FIG. 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.

Note that the example shown here is a schematic diagram; in actual industrial clean rooms, in addition to the equipment shown in the diagram, additional equipment such as an outdoor air conditioner and a humidifier are usually installed, but these are not shown here.

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

JP 2008-128618 A

In the conventional clean rooms described above, a space partitioned off from the target space S is required around the target space S for air circulation, maintenance, and the like. In particular, above the ceiling 1 (attic), on which the numerous blower units 2 are installed, a space with a certain degree of floor area and height must be provided to ensure air flow to the blower units 2 and to enable maintenance of the blower units 2.

In order to widely supply the non-unidirectional airflow as described above to the target space S, it is necessary to construct a large-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 large-area ceiling using the blower units and blanking panels in order to place the blower units at regular intervals.

Furthermore, negative pressure is generated in the space above the ceiling as the blower unit 2 operates. In the case of industrial clean rooms, 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. In this way, the installation of a wide ceiling and space above the ceiling is a factor in increasing the costs of constructing the target space S as a clean room.

In view of the above situation, 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 blower unit.

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 below the supply port within the target space and which draws in the air supplied from the supply port, purifies it, and sends it out downwards, an intake port 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, wherein the air sent out from the blower unit flows along the floor of the target space and then rises and is sucked into the intake port, and wherein a blower section with the blower unit disposed on a lower ceiling installed below the upper ceiling is provided in a portion of the target space, and the supply port is provided above the blower section .

In the clean room air conditioning system of the present invention, the intake port may be provided in the upper ceiling.

The clean room air conditioning system of the present invention can reduce the area required for the installation surface of the air blower unit while maintaining a sufficient level of cleanliness in the target space.

1 is a schematic elevational view showing an example (first embodiment) of a configuration of an air conditioning system for a clean room according to the present invention; FIG. 2 is a schematic plan view of the air conditioning system of FIG. 1 . FIG. 11 is a schematic elevational view showing another example (second embodiment) of a configuration of an air conditioning system for a clean room according to the present invention. FIG. 4 is a schematic plan view of the air conditioning system of FIG. 3 . FIG. 11 is a schematic elevational view showing yet another example (third embodiment) of the configuration of the air conditioning system for a clean room according to the present invention. FIG. 6 is a schematic plan view of the air conditioning system of FIG. 5 . 1A and 1B show 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 flow velocity in a reference example of the present invention, and (B) shows the distribution of air flow velocity in an embodiment of the present invention. 1A and 1B show the results of simulating the air flow and conditions in an air conditioning system for a clean room, 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. 1A and 1B show the results of simulating the air flow and conditions in an air conditioning system for a clean room, in which (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. FIG. 1 is a schematic elevational view showing an example of a conventional air conditioning system for a clean room.

The following describes an embodiment of the present invention with reference to the attached drawings.

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

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 for 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 that is sandwiched above and below by the upper ceiling 10 and the 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.

The ventilation unit 2 installed on the lower ceiling 11 is a device known as a fan filter unit (FFU) or the like that is equipped with a fan and a filter (e.g., a HEPA filter or ULPA filter) in a housing, and 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.

In addition, a hanging wall 9 is provided on the lower ceiling 11 so as to extend downward from near the air outlet of the blower unit 2, and as described below, this is designed to adjust the direction of the air blown out from the blower unit 2.

In this specification, expressions such as "downward" and "sideways" are used in relation to air flow, but these do not refer only to directions that exactly match the vertical or horizontal directions, but rather to directions that can be generally considered to be "downward" or "sideways" in the normal sense, or in an air conditioning system such as this invention. Similarly, expressions such as "along the floor" do not only refer to a direction that exactly matches the surface of the floor, but rather to the extent that it 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."

Above the area where the blower 8 is installed, the upper ceiling 10 is provided with a supply port 10a that supplies conditioned air to the room. In addition, at an appropriate position in the upper ceiling 10, in an area far from the blower 8, an intake port 10b that draws in air from the room is provided. The arrangement of the supply port 10a and intake port 10b will be described in detail later.

A duct 20 is provided on the upper side of the upper ceiling 10, forming an air flow path between the intake port 10b and the supply port 10a, and an air conditioner 21 is provided in the middle of the duct 20. Note that here, the duct 20 is illustrated in an area outside the target space S on the upper ceiling 10, but the duct 20 can 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 has 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 it as conditioned air from the supply port 10a. The cooling unit 21a is, for example, a coil through which a refrigerant flows, and draws in the refrigerant from an external heat source unit 22, exchanges heat with the air flowing outside the coil, and then returns the refrigerant to the heat source unit 22. Note that, although an air conditioner equipped with a cooling unit 21a is 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.

The floor 13 of the target space is not constructed as a punching panel or grating, unlike the floor 3 in the conventional example shown in FIG. 10. In principle, the floor 13 in this first embodiment is a structure that is completely closed, 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 below (although it is possible to provide holes for passing some members such as cables, etc., as necessary, as long as they do 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, etc., but it does not need to be high enough for 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 operated.

The setting of the area in which the blower section 8 is to be installed, and the arrangement of the supply port 10a, intake port 10b, and hanging wall 9 will be explained. 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 approximately rectangular overall in plan view. Two rows of blower units 2 are provided linearly along the longitudinal direction of the lower ceiling 11, forming a total of two blower sections 8 along the walls.

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

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

From the perspective of air flow, which will be described later, 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." 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 over 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 equipment 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.

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 this first embodiment, in a plan view, it is provided on the same side as the intake port 10b when viewed from the blower unit 2, that is, in the direction intended for guiding air when viewed 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 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), it is possible to omit the hanging wall.

The air flow in this first embodiment will be described. As shown in FIG. 1, clean air is sent downward toward the floor 13 of the target space S from the blower unit 2 provided in the blower section 8 at the wall. The downward air collides with the floor 13 and changes direction along the surface of the floor 13, but in the case of this 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 air flow sent out from another adjacent blower unit 2. Most of the air sent out downward from the blower unit 2 and changed direction along the floor 13 is blocked by these in three directions and guided to the remaining one 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 also flows in the remaining one direction). Here, the "target direction" refers to the direction of the area to which air is 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 located. In terms of the drawing, it is the right for the blower units 2 arranged in the left row, and the left for the blower units 2 arranged in the right row. Also, the suction port 10b is located in the upper ceiling 10 at a position that corresponds to the target direction as viewed from the blower unit 2 in a plan view.

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 air crawls along the top 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 the density difference 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.

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 air movement described above occurs for each of these 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.

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 rising air is an intake port 10b located in the upper ceiling 10, and air is sucked in through this intake port 10b.

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 through the filter of the blower unit 2 and is sent again below the blower section 8 as clean air.

Here, as described above, a hanging wall 9 is provided near the blower unit 2 on the underside of the lower ceiling 11 that constitutes 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 that has just been sent out from the blower unit 2 is drawn back into the blower unit 2 before it reaches 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 energetically inefficient.

Therefore, if a hanging wall 9 is provided near the air outlet of the blower unit 2 (in this first embodiment, the position opposite the nearby wall 7 when viewed from the blower unit 2), the air flow sent downward from the blower unit 2 is prevented from mixing with the air flow rising 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 another air flow, and the air flow is guided in the remaining one direction along the floor 13, but here the hanging wall 9 is provided in a position corresponding to that one direction (the direction in which the air is guided) when 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.

Thus, in the air conditioning system of the first embodiment, as shown in FIG. 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.

In addition, the air sent out from the blower unit 2 and flowing along the floor 13 picks up heat from the equipment 5 as it travels over the floor 13 and becomes warmer. Some of the warmed air rises to a height near the upper ceiling 10 before reaching the position of the intake port 10b in a plan view. The air at a height near the upper ceiling 10 is sucked in through the intake port 10b. Here, it is possible that some of the air will not reach the position of the intake port 10b, but will be attracted to the blower unit 2 and sent out downward from the blower unit 2; however, in the case of this 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 by the suction port 10b, and also, compared to the cold air sent out from the blower unit 2 and flowing along the floor 13, the heated air rises, forming a temperature stratification, and it is believed that the two do not easily mix together (the cold air located below does not pass through the layer of warm air located above and is guided to the blower unit 2).

The example shown here is a schematic diagram, and in actual industrial clean rooms, in addition to what is shown in the diagram, various other equipment such as outdoor air conditioners, humidifiers, and even rails and transport vehicles for transporting products are usually installed as necessary. However, such configurations that are not directly related to the gist of this invention have been omitted from the illustrations here.

The air conditioning system of 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 instead of the space above the ceiling as the air flow path, 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 like the space above the ceiling in Fig. 10.

In the conventional example of FIG. 10, the entire ceiling 1 was 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 easier to arrange, for example, tall devices and equipment. In this first embodiment, it is still necessary to secure a certain amount of area for the lower ceiling 11 near the blower unit 2 for maintenance purposes, but compared to the conventional example shown in FIG. 10, the area in which the height of the space can be effectively utilized can be significantly larger.

In addition, in the conventional example of FIG. 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, making it possible to secure a large space that can be used as a clean room. Also, because air is not circulated under the floor, no measures are required to maintain high air cleanliness there.

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 drawn into 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.

Furthermore, this first embodiment utilizes temperature stratification to efficiently cool the target space S at a height close to the floor 13 that requires air conditioning, which is also 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 the air is heated by receiving heat generated by the equipment 5. For this reason, it was necessary to adjust the entire area below the ceiling 1 where the blower unit 2 is installed to an appropriate temperature, but in the case of this 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 temperature rise due to the heat of the equipment 5, but in the case of this first embodiment, the air that has been heated by absorbing the heat of 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 of the blowing unit 2, so 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.

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 and to be used by 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.

In the case of this first embodiment, the air is driven by sucking in air from the intake port 10b provided at an appropriate position on the upper ceiling 10 (in the desired direction as viewed from the blower unit 2), which allows the air to reach a position far from the blower unit 2. The movement of the air blown out from the blower unit 2 is, of course, driven primarily by the operation of the blower unit 2, but in this first embodiment, the intake port 10b is provided at the position to which the air is to be guided as viewed from the blower unit 2, and air is sucked in from here, 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 (intake port 10b).

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 to the target space S from the blower unit 2 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, enabling clean air to be efficiently delivered to devices other than the equipment 5 located directly below the blower unit 2. This makes it possible to fully achieve a cleanliness level of around class 6, for example. The flow of air in the target space S will be described in more detail later.

In addition, in the case of the first embodiment, the cooling unit is not installed in the target space S, but the air sucked in 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 transfer 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. By placing the cooling unit 21a outside as in this first embodiment, even if condensation or water leakage occurs, it is possible to effectively prevent this from affecting the operation of the equipment.

In addition, when the cooling unit 6 is installed in the target space S as in the conventional example shown in Figure 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 this case, the cost of installing the air conditioning equipment can be reduced.

In the first embodiment, no wall-like structure is provided to separate the area in the target space S where the blower 8 is provided from the other areas. However, for example, a side wall may be provided along the edge of the lower ceiling 11, forming a surface along the vertical direction between the upper ceiling 10, 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. Furthermore, when such a side wall is provided, the side wall may be provided with an air vent as necessary.

Here, if 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 close 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 assumed that almost all of the air supplied from the supply port 10a passes through the blower unit 2, and no problem will arise in maintaining cleanliness.

Figures 3 and 4 show another example (second embodiment) of the arrangement of equipment in an air conditioning system according to the present invention (note that in Figure 3, the air conditioner 21 and heat source unit 22 in Figure 1 are omitted. The same applies to Figure 5 described later). In the first embodiment shown in Figures 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 this 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.

When the blower 8 is arranged in this way, 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 Figures 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 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 arranged, the air flow sent out from the blower unit 2 side and moving along the floor 13 collides with the wall 7 and starts to rise. In addition, 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 in the upper ceiling 10 or drawn into the blower unit 2. In this way, as shown in Figure 3, an air circulation is created that is roughly half the air flow in the first embodiment (see Figure 1), and the target space S, which is a clean room, is created in the same way as in the first embodiment.

Figures 5 and 6 show yet another example (third embodiment) of the equipment 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, as in the first embodiment, but in addition, a third row of blowers 8 is provided in the central area of the room.

This third row of blowers 8 is arranged parallel to the first and second rows of blowers 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, assuming that the left blower 8 in Figures 5 and 6 is the first row and the right blower 8 is the second row.

An intake port 10b is provided in the upper ceiling 10 at a position halfway between the first and third rows of blowers 8 in a plan view. A similar intake port 10b is also provided to the right of the third row of blowers 8 (closer to the second row of blowers 8) in a plan view.

The air sent out from the blower unit 2 in the first row (left side) collides with the floor 13, and as in the first embodiment shown in Figures 1 and 2, 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). 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).

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, the air flow coming from the blower unit 2 in the second row exists in one direction, the downward flow of air sent out from the adjacent blower unit 2 in the third row exists in another direction, and the 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 in the remaining direction (to the left), which is the desired direction.

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

When the air flow sent out from the second row of blower units 2 and moving leftward along the top surface of the 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 the suction port 10b above the floor 13.

In this way, the air sent out from the first and third row of blower units 2 is circulated in a manner generally similar to that of the first embodiment shown in Figures 1 and 2, and the air sent out from the second row of blower units 2 is circulated in a manner generally similar to that of the second embodiment shown in Figures 3 and 4. This achieves a target space S that is a clean room, similar to the first and second embodiments described above.

Air circulation 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 in the desired direction.

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 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 Coanda effect is used to make the airflow reach a long distance, but in that case, if the downward airflow is simply made to collide with the floor 13, the flow 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 device 5 is also utilized to allow a constant volume of air to reach long distances.

In this way, by skillfully arranging the blower units 2, intake ports 10b, walls 7, etc., it is possible to appropriately guide the air flow in the desired direction with a simple configuration. Furthermore, even in a large clean room, by appropriately combining these, clean air at the appropriate temperature can be supplied 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 blower units 2 may be provided. In addition to the air flow and walls 7, it is also possible to provide other objects or structures (such as screen-like objects) to guide the air flow or to make it collide and rise.

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.

In the reference example shown in (A) of each figure, a configuration equivalent to the suction port 10b in each embodiment shown in Figs. 1 to 6 is not provided. Instead, an suction port (indicated by the 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, from which heated air is sucked in. The space from the suction port 10c to the blower unit 2 is separated from the rest of the space by the lower ceiling 11 and a side wall (indicated by the 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.

In each simulation, the conditions were set such that no equipment was placed on the floor for both the reference example (A) and the working example (B).

First, referring to FIG. 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 a short circuit has occurred in which the air sent out from the air outlet of the blower unit 2 rises and is sucked into the air inlet 10c before it can reach far from the air outlet (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 top of 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.

Next, referring to FIG. 8, it can be seen that in the embodiment (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 an ideal 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 (A), although low-temperature air is distributed in the left-most area, 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.

The same is true for the air age shown in Figure 9. In the example (B), the young air spreads almost uniformly along the floor 13 from the position of the air outlet of the blower 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 (A), air with a particularly young air age does not reach the space at the left end. This is thought to be due to the short circuit described above.

In this way, in this embodiment, air is sucked in through the intake port 10b, which is provided in the direction in which air is blown out as viewed from the blower unit 2, and the air in the target space S can be efficiently guided far away, achieving suitable air conditioning in the target space S, which is a clean room.

As described above, the air conditioning system for the clean room in 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 attracts, purifies, and sends out the air supplied from the supply port 10a downward, the suction port 10b provided above the floor 13 of the target space S, the duct 20 that connects the supply port 10a and the suction port 10b, and the air conditioner 21 provided in the middle of the duct 20. 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 suction port 10b. In this way, the air suction from the suction 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 far away. In addition, since the duct 20 is used as the return air flow path, there is no need to install a large space such as a space above the ceiling as the return air flow path.

In the clean room air conditioning system of this embodiment, a blower section 8 with a blower unit 2 is provided in a portion of the target space S on a lower ceiling 11 installed below an upper ceiling 10, 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 use the space more efficiently.

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

Therefore, according to each of the above embodiments, a clean room can be realized in an appropriate manner while saving space and at low cost.

The clean room air conditioning system of the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the spirit of the present invention.

2 Blower unit 8 Blower section 10 Ceiling (upper ceiling)
10a Supply port 10b Suction port 11 Ceiling (lower ceiling)
13 Floor 20 Duct

Claims (2)

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;
and an air conditioner provided in the middle of the duct,
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 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.
A clean room air conditioning system characterized by: 2. The air conditioning system for a clean room according to claim 1 , wherein the suction port is provided in the upper ceiling.

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