Stratified air conditioning system

Abstract

To provide a stratified air-conditioning system capable of performing stratified air-conditioning efficiently for a limited region of a target space in an interior zone.SOLUTION: A part of a target space S that is not surrounded by walls in an interior zone is defined as a target area A; an outer peripheral part of the target area A in a plan view is provided with a blowout duct 3 comprising a blowout port 3a through which conditioned air supplied from an air conditioner 1 flows and that blows out the conditioned air downward; and the conditioned air is blown out toward the inside of the target area A from the blowout port 3a. A blowout angle of the conditioned air at the blowout port 3a is set to be 15° or more and 45° or less with respect to a vertical surface along a direction in which the blowout duct 3 extends.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a stratified air conditioning system used in large spaces such as factories, particularly in interior zones. [Background technology]

[0002] In facilities with large spaces with high ceilings, such as factories, a temperature stratification air conditioning system may be installed in which a loop duct is installed in the perimeter zone and a downward airflow is blown out from the loop duct to perform air conditioning, as described in Patent Document 1 below. In this type of air conditioning system, particularly during cooling, the work area below the loop duct is efficiently air-conditioned, while the unoccupied areas above are not cooled. In this way, energy can be saved while optimally air-conditioning the occupied areas that require air conditioning. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-1892 Summary of the Invention [Problem to be solved by the invention]

[0004] In such a stratified air-conditioning system, the conditions of the space to be air-conditioned are not necessarily uniform, and it is possible that even within the same space, there may be areas where people are frequently present and where air conditioning is highly necessary, and areas where there are few people and where air conditioning is not highly necessary. In such a case, an air-conditioning system such as that described in Patent Document 1 above will uniformly air-condition a space where the former and latter areas coexist, but if it were possible to focus air-conditioning on the former areas, the energy efficiency of air-conditioning could be further improved.

[0005] One possible solution to this demand, other than stratified air conditioning, is the use of spot air conditioning. Rather than adjusting the entire space to a comfortable temperature, spot air conditioning delivers conditioned air locally to areas where people are present. However, this approach limits the area where comfort is maintained. When air is blown locally into a space from a simple nozzle at a certain directional speed, the blown air attracts and mixes with the surrounding air, causing it to disperse into the moving surrounding air. Therefore, even when conditioned air is supplied in the form of spot air conditioning, the comfortable temperature range is limited to a small area near the outlet in terms of both direction and distance. While increasing the blown air velocity can expand the area within the comfortable temperature range, in this case, strong airflows near the outlet may create an unpleasant draft feeling. Despite the draft feeling, a significant amount of energy is required to blow conditioned air toward people at a volume that is sufficient to overcome the mixing and diffusion caused by the surrounding air. In addition, typical spot air conditioners package a complete refrigeration cycle, blowing air cooled in an evaporator, which then blows the refrigerant into a condenser using a separate fan built into the same package, discharging the waste heat into the air around the device. Depending on the number and location of these spot air conditioners, they can obstruct people's movement and reduce the efficiency of necessary work. Therefore, while spot air conditioning is effective in places where the people to whom the conditioned air is supplied remain in the same place, it is not sufficient in situations where people move around even slightly.

[0006] Furthermore, factories and other facilities often have equipment installed and operating that generates a lot of heat. Air-conditioning the entire factory, including the areas where such equipment is installed, would require the air conditioning to handle the heat load generated by the equipment, resulting in significant energy consumption. Even in areas with high heat loads and high energy consumption related to air conditioning, air conditioning is necessary in areas where people are present and work. However, if there are areas within the target space that have high heat loads and are rarely visited by people, excluding these areas for air conditioning would still enable energy-efficient air conditioning operation. However, if air conditioning is focused on the interior zone, particularly the former areas where people are present and work, the downward airflow along the exterior walls cannot be used to redirect the airflow, and it is necessary to generate an airflow that envelops the former areas in a wall-less space.

[0007] In view of the above circumstances, the present invention aims to provide a stratified air-conditioning system that can efficiently perform stratified air-conditioning in a limited area in the interior zone of a target space. [Means for solving the problem]

[0008] In the present invention, a part of the interior zone of the target space that is not surrounded by walls is set as the target area, an air outlet duct through which conditioned air supplied from an air conditioner flows and which has an outlet for blowing the conditioned air downward is provided on the outer periphery of the target area in a plan view; a blowing angle of the conditioned air at the air outlet is inclined toward a target area by 15° to 45° with respect to a vertical plane along the extension direction of the air outlet duct, The air outlet is configured to blow conditioned air toward the inside of the target area, The conditioned air that reaches the floor of the target space moves along the floor toward the inside of the target area due to the Coanda effect. thing This relates to a stratified air conditioning system characterized by the above.

[0010] In the stratified air conditioning system of the present invention, a return air outlet may be provided at a height within the target area that is below the height of the outlet duct but above the floor level, which takes in return air within the target area and returns it to the air conditioner.

[0011] In the stratified air-conditioning system of the present invention, the set height level of the outlet duct may be in the range of 2.5 m to 6 m from the floor, and the installation pitch of the outlets provided in the extension direction of the outlet duct may be in the range of 300 mm to 1500 mm.

[0012] In the stratified air-conditioning system of the present invention, the outlet duct may be supported on a walkway installed in the target space. [Effects of the Invention]

[0013] The stratified air-conditioning system of the present invention can provide the excellent effect of efficiently performing stratified air-conditioning on a limited area in the interior zone of a target space. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view showing an example of a stratified air-conditioning system according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional elevation view of the stratified air-conditioning system of FIG. 1. [Figure 3] FIG. 2 is a plan view of the stratified air-conditioning system of FIG. [Figure 4] 2 is a cross-sectional elevation view showing an example of the configuration of an air outlet in the stratified air-conditioning system of FIG. 1. FIG. [Figure 5] FIG. 10 is an elevation view showing another example of the arrangement of the outlet duct in a stratified air conditioning system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0016] 1 to 4 show an example of a stratified air-conditioning system according to the present invention. The stratified air-conditioning system of this embodiment includes an air conditioner 1 that sends out conditioned air, and an air supply duct 2 through which the conditioned air supplied from the air conditioner 1 flows.

[0017] 1 and 3, a portion of the supply air duct 2 is annular, and is provided with an outlet 3a for conditioned air (hereinafter, the portion of the supply air duct 2 that has this outlet 3a will be referred to as the "outlet duct 3"). The area surrounded by this annular supply air duct 2 is the area of ​​the target space S that is the target for air conditioning in the stratified air-conditioning system of this embodiment (hereinafter, this area will be referred to as the "target area A").

[0018] The discharge duct 3 is installed at an appropriate height (for example, about 2.5 to 6 m from the floor) in the target space S, roughly parallel to the floor. The air conditioner 1 is installed at roughly the same height as the discharge duct 3 or higher, and the conditioned air outlet of the air conditioner 1 is connected to one location on the discharge duct 3 by a supply duct 4, which is part of the intake air duct 2, so that the conditioned air sent out from the air conditioner 1 is supplied to the discharge duct 3 through the supply duct 4.

[0019] An air outlet 3a is provided on the underside of the discharge duct 3, and the conditioned air circulating inside the discharge duct 3 is blown downward from the air outlet 3a. The air outlet 3a is nozzle-shaped and is inserted into the inside of the discharge duct 3 so that its air inlet portion protrudes. The air outlet 3a is cylindrical, and its central axis is perpendicular to the bottom surface of the discharge duct 3, with the air inlet portion protruding as an upper open end parallel to the duct central axis. The insertion length may be longer than 0 cm and less than half the internal height of the discharge duct 3 (equal to the distance to the duct central axis). This is because the air velocity distribution within the discharge duct 3, in a cross section perpendicular to the direction of air movement, is slower near the top, bottom, and left and right sides of the discharge duct 3 due to frictional resistance on the inner surface, and then increases toward the duct's center axis. Therefore, the dynamic pressure at the upper opening of the discharge outlet 3a can be re-established as static pressure by the airflow velocity within the duct at that location—that is, the static pressure converted from dynamic pressure. This mechanism allows multiple discharge outlets 3a, arranged at a predetermined pitch along the length of the discharge duct 3, to convert the local dynamic pressure into similar static pressure and then redirect it back into dynamic pressure, regardless of the distance from the supply duct 4 connection port, thereby enabling each discharge outlet 3a to discharge air at a similar volume and velocity. As shown in Figure 4, the discharge portion of the discharge outlet 3a from the bottom of the duct is angled downward rather than vertically, so that conditioned air is blown toward the inside of the target area A. The setting of the discharge angle of the conditioned air from the discharge outlet 3a will be described in detail later.

[0020] A return air outlet 5 is installed in a portion of the target area A surrounded by the outlet duct 3, and the return air outlet 5 is connected to the inlet side of the air conditioner 1 via a return air duct 6. A portion of the air in the target area A is taken in as return air from the return air outlet 5, returned to the air conditioner 1 through the return air duct 6, and sent out again to the outlet duct 3 as conditioned air.

[0021] The installation position and installation conditions of the blow-out duct 3 will be described. In this embodiment, the target space S is assumed to be, for example, a factory workroom, and in factories, etc., walkways are installed at positions higher than the floor for purposes such as maintenance. In this embodiment, the blow-out duct 3 is supported by being suspended from this walkway 7 (see FIG. 3; for convenience of explanation, the walkway 7 is omitted from FIGS. 1 and 2). The walkway 7 is usually installed above people's heads in factories, etc., at a height that does not interfere with people walking on the floor (for example, a height such that the underside of the walkway is located about 3 m above the factory floor).

[0022] On the other hand, the area assumed as the target area A is generally an area where people are present. In this case, it is preferable to install the air outlet 3a at a height approximately above people's heads. This is because limiting the area to be air-conditioned to a comfortable state for people to the height where people are present allows for more efficient air conditioning. In addition, it is preferable to position the air outlet 3 at a height above people's heads to avoid interference between the air outlet 3 and people. For these reasons, the height at which the air outlet duct 3 is installed is preferably approximately 2.5 m to 6 m above the floor of the target space S. Furthermore, if a walkway is provided at an appropriate height, approximately 2.8 m to 6 m above the floor, installing the air outlet duct so that it is supported by this walkway minimizes the construction effort and materials required to install the air outlet duct at the appropriate height.

[0023] Of course, when installing the blow-out duct, if there is a suitable structure other than the walkway, it may be used, or if there is no suitable structure, a structure to support the blow-out duct may be installed separately. Also, the blow-out duct does not have to be hung from the walkway (or other structure), but may be installed by placing it on top, for example.

[0024] Furthermore, the blowout duct 3 does not necessarily have to be installed at a uniform height. Depending on the situation of surrounding structures and equipment, for example, as shown in Fig. 5, a single blowout duct 3 may be installed at different heights. In the target space S, such as a factory workroom, it is possible to imagine a situation in which many types of equipment and structures are installed in an intricate manner. In such a case, the installation height of the blowout duct 3 can be changed as appropriate so that the blowout duct 3 does not interfere with them.

[0025] Furthermore, as described above, the discharge duct 3 is provided on the outer periphery of the target area A so as to surround the target area A in a plan view. The "target area" refers to a space such as a production room in a factory, a portion of the "target space" to be air-conditioned, and is the area that is the primary target of air conditioning in the stratified air-conditioning system of the present invention. Specifically, it refers to an area where people are present and working, or an area where equipment or items requiring temperature control (e.g., equipment whose operation is adversely affected by high temperatures or items whose quality is impaired) are located. In such areas, partitions cannot be erected due to process requirements, and the space is connected to the surrounding area. Generally, a space to be air-conditioned may contain areas where the need for air conditioning is high and areas where the need for air conditioning is not so high. However, in the stratified air-conditioning system of the present invention, the former area (or a larger area including this) is set as the target area, and this area is surrounded by the discharge duct 3 for air conditioning.

[0026] It should be noted that the phrase "the supply air duct (or the blow-out duct) surrounds the target area" does not necessarily mean that the supply air duct or the blow-out duct surrounds the entire periphery of the target area. For example, even if a supply air duct that is U-shaped in plan view is installed along about 70% of the entire periphery of the target area, it can generally be said that "the supply air duct surrounds the target area."

[0027] Furthermore, when setting the target area in this manner, if, for example, equipment that generates a lot of heat is installed in the target space but the area around this equipment does not require much air conditioning, it is advisable to exclude this equipment from the target area. In this embodiment, as shown in Figures 1 and 3, equipment 8 that generates a lot of heat is installed in the target space S, and the target area A is set to avoid this equipment 8. In other words, the air discharge duct 3 is positioned so that the area surrounded by the air discharge duct 3 does not include the area where the equipment 8 is installed. If the equipment 8 that generates a lot of heat were installed in the target area A, the heat generated by this equipment 8 would be included in the heat load when air conditioning the target area A, resulting in increased energy consumption for air conditioning. Of course, if there are people in the area around the equipment 8 or if the equipment 8 itself requires temperature control, then the area where the equipment 8 is installed can be included in the target area A, regardless of the amount of heat generated by the equipment 8, and this area can also be subject to air conditioning. However, if such circumstances do not exist, the target area A can be set to avoid the equipment 8 that generates a lot of heat, eliminating the need to use air conditioning to deal with the heat generated by the equipment 8, and the energy required can be significantly reduced.

[0028] The installation of the air outlet 3a will now be described. The air outlet 3a is provided on the underside of the outlet duct 3 and is designed to blow out the conditioned air circulating inside the outlet duct 3 downward, but the direction in which the conditioned air is blown out is not vertical but diagonally downward. Specifically, the air outlet 3a is designed to blow out the conditioned air in a direction closer to the inside of the target area A with respect to a vertical plane along the extension direction of the outlet duct 3.

[0029] In a conventional temperature stratification air conditioning system such as that described in Patent Document 1, a loop duct is installed along a wall in the perimeter zone, and conditioned air is blown out vertically downward from the outlet of the loop duct. In this arrangement, the conditioned air blown downward from the outlet and hitting the floor surface inevitably flows inward because the outside of the loop duct is blocked by the wall in a plan view, which forms temperature stratification within the area surrounded by the loop duct, resulting in optimal stratified air conditioning.

[0030] In contrast, in the stratified air-conditioning system of this embodiment, a portion of a target space S partitioned by walls is set as a target area A, and the air outlet duct 3 is provided so as to surround this target area A in a plan view. In other words, the air outlet duct 3 is not necessarily provided in the perimeter zone, and is not necessarily installed along a wall. If the air outlet duct 3 installed in such a position were to blow conditioned air vertically downward, approximately half of the conditioned air that reaches the floor surface would flow toward the inside of the target area A, and the other half would dissipate outside the target area A. This would result in wasted energy when air-conditioning the target area A with a focus on the interior.

[0031] Therefore, in this embodiment, the blowing angle of the conditioned air from the outlet 3a is set toward the inside of the target area A, rather than in the vertical direction. It is even better to set the end of the conditioned air flow diffusing from the outlet 3a opposite the target area A to be vertical. In this way, much of the conditioned air flow blown out from the outlet 3a has a vector pointing inward toward the target area A. Therefore, coupled with the Coanda effect, the conditioned air that reaches the floor moves toward the inside of the target area A along the floor. When cooling the target area A, this slow flow of conditioned air is formed along the floor within the target area A. At the same time, below the installation position of the outlet duct 3 on the periphery of the target area A, the conditioned air blown out from the outlet 3a at a high speed of approximately 2.5 m / s to 8 m / s attracts and entrains the surrounding air, generating a large airflow in the same direction, forming an air curtain. This air curtain is formed inward relative to the target area A by setting the discharge angle of the air outlets 3a, minimizing the amount of conditioned air leaking outside the target area A. Furthermore, if the installation pitch of the multiple air outlets 3a along the extension of the discharge duct 3 can be set between 300 mm and 1500 mm, it is more preferable because the induced air that forms the air curtain will flow in the same direction without interruption. In this way, within the target area A, the conditioned air, which is cool, forms a layer from the floor to at least the height of the discharge duct 3, and stratified air conditioning is performed intensively, suitably, and efficiently only in the target area A of the target space S.

[0032] A blowing speed of the conditioned air from the outlet 3a of approximately 2.5 m / s to 8 m / s is suitable for forming an air curtain on the periphery of the target area A and for forming temperature stratification within the target area A. The blowing angle of the conditioned air from the outlet 3a is preferably approximately 15° to 45° with respect to a vertical plane along the extension direction of the outlet duct 3. If the blowing angle of the conditioned air is too close to the vertical, a significant proportion of the main flow of the conditioned air will be directed toward the outside of the target area A in a plan view, causing the conditioned air to dissipate outside the target area A and reducing the efficiency of air conditioning. On the other hand, if the blowing angle of the conditioned air relative to the vertical direction is too large, the distance from the outlet 3a to the floor surface will be longer, causing the flow of conditioned air blown out from the outlet 3a to lose speed and diffuse before reaching the floor surface, which may result in poor formation of an air curtain or stratification of the conditioned air due to the Coanda effect.

[0033] The mechanism for setting the blowing angle at the outlet 3a may be to angle the tip of the pipe that constitutes the outlet 3a as shown in Figure 4, or other mechanisms such as providing a louver at the outlet are also possible. Any mechanism for the outlet may be used as long as it can give the conditioned air an appropriate blowing angle and direct the air in one direction without impairing the initial velocity.

[0034] The return air vent 5 is installed in the center of the target area A in a plan view, and at that position, it takes in a portion of the conditioned air within the target area A as return air. The conditioned air blown inward into the target area A from the outlet 3a of the outlet duct 3 gathers in the center of the target area A, where the air currents that have crawled along the floor collide due to the Coanda effect, generating an upward flow. This, combined with the thermal updraft, allows the return air vent 5 to be installed at that position, thereby enabling efficient recovery of the conditioned air. Note that although only one return air vent 5 is shown in Figures 1 to 3, depending on the conditions within the target area A, return air vents 5 may be installed at multiple positions within the target area A. In this case, multiple return air vents 5 may be installed in a single return air duct 6, or multiple return air ducts 6 may be installed, or they may be installed in a branched configuration as appropriate.

[0035] If the return air vent 5 is installed at a height equal to or lower than the outlet duct 3, but above floor level, it will take in the conditioned air that forms a layer within the target area A, thereby further reducing the energy required for air conditioning. However, depending on the arrangement of equipment and the location of structures within the target space S, it may not be possible to install the return air vent 5 at such a height. In such cases, the return air vent 5 may be installed at a higher position than the outlet duct 3. However, if the return air vent 5 is installed at a higher position than the outlet duct 3, it will take in high-temperature air that is above the conditioned air that forms a layer at an appropriate temperature as return air, resulting in the accumulation of low-temperature air and the thinning of the layer of high-temperature air that forms the stratification above it, thereby reducing the effect of temperature stratification and slightly reducing energy efficiency during cooling.

[0036] Regarding the installation position of the air conditioner 1, the example shown here is one where it is installed at the same height as the outlet duct 3 within the target area A, but it may be installed at an appropriate position depending on the arrangement of the outlet duct 3, other equipment, structures, etc. in the target space S.

[0037] In addition, when implementing a stratified air conditioning system such as this embodiment, various other facilities and equipment are also installed, such as an outdoor air duct that takes in outdoor air to the air conditioner 1, an outdoor air conditioner that pre-conditions the outdoor air taken in from the outdoor air duct, and other various facilities and equipment, but configurations that are not directly related to the purpose of the present invention are not shown in the illustration.

[0038] In the stratified air-conditioning system of this embodiment, a target space S, which contains both high- and low-need areas for air conditioning, is selected as the area to be primarily air-conditioned. The area without partition walls is designated as target area A, and target area A is surrounded by outlet duct 3. Air conditioning is performed using air curtains and temperature stratification. Since there are no walls around target area A, the angle at which conditioned air is blown from outlet duct 3 is carefully adjusted to minimize dissipation of conditioned air and achieve efficient air conditioning within a limited area. Even within the same target space S, the system can avoid installation of high-heat-generating equipment 8, thereby achieving even greater energy efficiency than air-conditioning systems such as those described in Patent Document 1. Furthermore, since this system provides air conditioning within a specific area, rather than spot air conditioning, which has a narrow, limited effective range, comfortable air conditioning conditions are maintained even when people move around within the area. The installation of spot air-conditioning systems does not impede traffic flow.

[0039] As described above, the stratified air-conditioning system of this embodiment is configured such that a partial area in the interior zone of the target space S that is not surrounded by walls is set as the target area A, conditioned air supplied from the air conditioner 1 circulates inside, and the air outlet 3 equipped with the air outlet 3a that blows the conditioned air downward is provided on the outer periphery of the target area A in a plan view, and the air outlet 3a blows the conditioned air toward the inside of the target area A. In this way, stratified air-conditioning can be performed efficiently for the target area A, which is the area of ​​the target space S that should be air-conditioned primarily.

[0040] In addition, in the stratified air-conditioning system of this embodiment, the blowing angle of the conditioned air from the air outlet 3a is set to be 15° or more and 45° or less with respect to a vertical plane along the extension direction of the air outlet duct 3. This makes it possible to effectively prevent the conditioned air from scattering outside the target area A.

[0041] Furthermore, in the stratified air-conditioning system of this embodiment, a return air vent 5 is provided at a height within the target area A that is lower than the height of the outlet duct 3 but higher than the floor level, which takes in return air within the target area A and returns it to the air conditioner 1. In this way, by taking in stratified conditioned air within the target area A, it is possible to further reduce the energy required for air conditioning.

[0042] In the stratified air-conditioning system of this embodiment, the set height level of the discharge duct 3 is in the range of 2.5 m to 6 m from the floor, and the installation pitch of the multiple air outlets 3a provided in the direction of extension of the discharge duct 3 is in the range of 300 mm to 1500 mm. In this way, the conditioned air that forms stratification within the target area A can be suitably taken in, thereby further reducing the energy required for air conditioning.

[0043] In addition, in the stratified air-conditioning system of this embodiment, the air outlet duct 3 is supported on a walkway 7 installed in the target space S. In this way, the air outlet duct 3 can be installed at an appropriate height with a minimum of construction work and materials.

[0044] Therefore, according to the present embodiment, it is possible to efficiently perform air conditioning on a limited area of ​​the target space.

[0045] The stratified air-conditioning system of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. [Explanation of symbols]

[0046] 1 Air conditioner 3. Air outlet duct 3a Air outlet 5 Return air port 7. Walkway A. Target Area S target space

Claims

1. The target area is a part of the interior zone of the target space that is not surrounded by walls. an air outlet duct through which conditioned air supplied from an air conditioner flows and which has an outlet for blowing the conditioned air downward is provided on the outer periphery of the target area in a plan view; a blowing angle of the conditioned air from the air outlet is inclined toward a target area by 15° to 45° with respect to a vertical plane along an extension direction of the air outlet duct, The air outlet is configured to blow conditioned air toward the inside of the target area, The conditioned air that reaches the floor of the target space is configured to move along the floor toward the inside of the target area, in conjunction with the Coanda effect. A stratified air conditioning system characterized by:

2. A return air outlet is provided at a height within the target area that is lower than the height of the blowout duct and higher than the floor level, and that takes in return air within the target area and returns it to the air conditioner.

2. The stratified air-conditioning system according to claim 1,

3. The set height level of the blowout duct is in the range of 2.5 m to 6 m from the floor surface, The installation pitch of the plurality of air outlets provided in the extension direction of the air outlet duct is set to be in the range of 300 mm to 1500 mm.

3. The stratified air-conditioning system according to claim 1 or 2,

4. The air outlet duct is supported by a walkway installed in the target space. The stratified air-conditioning system according to any one of claims 1 to 3,

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