Air conditioning facility in plant and method for controlling air conditioning facility in plant

Abstract

To suppress room pressure fluctuation in a clean area provided in a plant.SOLUTION: An air conditioning facility in a plant comprises a first facility 20 that adjusts a room pressure in a clean area 11 where a production device 15 is installed; a second facility 40 that is adjacent to the clean area 11, and adjusts a room pressure in a semi-clean area 12 into which air flows from the clean area 11 so that it is lower than the room pressure in the clean area 11; and a local exhaust device 23 that exhausts air in or around the production device 15. In conjunction with the operation of the local exhaust device 23, the first facility 20 exhausts air so that the room pressure in the semi-clean area 12 is maintained in a range higher than that of the clean area 11.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an air conditioning system for a factory and a method for controlling the air conditioning system for a factory. [Background technology]

[0002] Food factories are zoned (divided into compartments) according to the production process for hygiene management. In the food hygiene management method described in Patent Document 1, the food factory is divided into clean work areas, semi-clean work areas, etc. In this method, the area where mixing or baking processes are carried out is designated as the clean work area. Such areas are generally maintained at positive pressure to prevent air from entering from other areas, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-049660 Summary of the Invention [Problem to be solved by the invention]

[0004] However, depending on the process carried out in the clean work area, ventilation may be required at all times due to increases in temperature or humidity, or the generation of oily smoke, etc. This can cause a drop in the room pressure in the clean area. Furthermore, similar issues exist not only in food factories but also in factories that use zoning. [Means for solving the problem]

[0005] In one embodiment, a factory air conditioning system is provided, comprising: a first system for adjusting the room pressure in a clean area where a production device is installed; a second system for adjusting the room pressure in an adjacent area adjacent to the clean area so that the room pressure is lower than the room pressure in the clean area; and a local exhaust system for exhausting air from within or around the production device, wherein the first system exhausts or supplies air in conjunction with operation of the local exhaust system so that the room pressure in the clean area is maintained higher than that in the adjacent area.

[0006] In one aspect, a method for controlling air conditioning equipment in a factory is provided. The factory includes a clean area where production equipment is installed, first equipment for adjusting the room pressure in the clean area, an adjacent area adjacent to the clean area, second equipment for adjusting the room pressure in the adjacent area so that it is lower than the room pressure in the clean area, and a local exhaust ventilation system for exhausting air from within or around the production equipment. In the method for controlling air conditioning equipment in the factory, the first equipment exhausts or supplies air in conjunction with operation of the local exhaust ventilation system so that the room pressure in the clean area is maintained higher than that in the adjacent area. [Effects of the Invention]

[0007] According to the present disclosure, fluctuations in room pressure in clean areas set up in factories can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of a food factory according to one embodiment. [Figure 2] FIG. 10 is a schematic diagram of a food factory according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] First Embodiment Hereinafter, a first embodiment of a factory air conditioning system and a control method therefor will be described. In this embodiment, the factory will be described as a food factory that produces food.

[0010] As shown in FIG. 1, a food factory 10 comprises a clean area 11, a semi-clean area 12, and a contaminated area 13. In this embodiment, these areas 11 to 13 are separated by walls 16. Entrances (not shown) are provided in the walls 16 of the areas 11 to 13. The entrances are equipped with doors or the like to prevent contamination of the highly clean areas. For example, in the clean area 11, food production and the like takes place. In the semi-clean area 12, packaging and storage of products and the like take place. In the contaminated area 13, materials and other transported goods are received and the like are received. Based on this zoning, the work flow of people and the transportation routes of goods and the like are determined.

[0011] Production equipment 15 is installed in the clean area 11. An example of production equipment 15 is equipment that heats food, etc. Production equipment 15, which is a heat source, is, for example, a fryer that deep-fries food in high-temperature cooking oil, a steamer, an oven, or a dryer, as well as equipment that sterilizes or disinfects objects such as food or containers. For example, in a fryer, the cooking oil can reach 200°C or higher. Such production equipment 15 can cause a severely hot environment for workers.

[0012] (Air conditioning system) The air conditioning system will now be described. The air conditioning system includes a first facility 20, a second facility 40, and a third facility 50. The first facility 20, the second facility 40, and the third facility 50 maintain each of the zones 11 to 13 at a positive pressure.

[0013] The air conditioning system includes a first equipment 20. The first equipment 20 conditions the air in the clean area 11. The first equipment 20 includes one or more air conditioners 21, a constant air volume control device 22, a local exhaust device 23, and a room pressure stabilizing exhaust device 24.

[0014] The air conditioner 21 takes in outside air and air from within the clean area 11. The air conditioner 21 purifies the air and adjusts the temperature, humidity, etc. of the air. The air conditioner 21 supplies the conditioned air to the clean area 11 via an air supply duct 25 and an air supply port 26. The air supply duct 25 also distributes air to the semi-clean area 12 and the contaminated area 13. A constant air volume control device 22 is provided midway through the air supply duct 25. The constant air volume control device 22 supplies a constant air volume (supply amount) of air to the clean area 11. The constant air volume control device 22 is composed of a sirocco fan, a damper, etc. The air from the clean area 11 returns to the air conditioner 21 from an exhaust port 27 provided in the floor 17 of the clean area 11 via an exhaust duct 28. The exhaust duct 28 is also connected to the semi-clean area 12 and the contaminated area 13. The amount of exhaust air discharged from the clean area 11 is approximately constant.

[0015] The local exhaust ventilation system 23 exhausts the air around or inside the production equipment 15 to the outside, such as outside the factory, so that heat, water vapor, oily smoke, dust, gas, etc. generated by the production equipment 15 do not accumulate in the clean area 11. The local exhaust ventilation system 23 includes an exhaust fan 31, an exhaust duct 32, and a hood 33. The hood 33 is installed to cover the source of the production equipment 15 from which heat, water vapor, etc. are to be exhausted. The exhaust fan 31 exhausts air drawn in through the hood 33 via the exhaust duct 32 to the outside. For example, the exhaust fan 31 is equipped with an exhaust detection sensor that detects the amount of exhaust. For example, the exhaust detection sensor is a rotation sensor (not shown) or an air volume sensor that detects the rotation speed of the exhaust fan 31. A portion of the air in the clean area 11 is returned to the clean area 11 after being conditioned by the air conditioner 21, and the remaining air is exhausted to the outside, so that a predetermined amount of air in the clean area 11 is constantly replaced.

[0016] The room pressure stabilization exhaust device 24 exhausts air from within the clean area 11. The exhaust volume of the room pressure stabilization exhaust device 24 can be changed. The room pressure stabilization exhaust device 24 stabilizes the room pressure (pressure) in the clean area 11 by adjusting the exhaust volume. The room pressure stabilization exhaust device 24 is equipped with a room pressure stabilization exhaust fan 29 and an exhaust duct 30. The room pressure stabilization exhaust fan 29 exhausts air from the clean area 11 to the outside via the exhaust duct 30.

[0017] The room pressure stabilization exhaust device 24 is linked to the operation and shutdown of the local exhaust device 23. Specifically, the room pressure stabilization exhaust device 24 decreases the exhaust rate when the exhaust rate of the local exhaust device 23 increases, and increases the exhaust rate when the exhaust rate of the local exhaust device 23 decreases. In other words, the room pressure stabilization exhaust device 24 controls the exhaust rate so that the sum of its own exhaust rate and the exhaust rate of the local exhaust device 23 remains approximately constant.

[0018] The local exhaust device 23 outputs a signal (or information) indicating the exhaust volume detected by the exhaust detection sensor to the room pressure stabilizing exhaust device 24. Alternatively, the local exhaust device 23 outputs an operation start signal to the room pressure stabilizing exhaust device 24 when it starts operating.

[0019] The room pressure stabilization exhaust device 24 acquires signals and the like from the local exhaust device 23. Furthermore, when the room pressure stabilization exhaust device 24 determines based on the acquired signals and the like that the exhaust volume of the local exhaust device 23 has increased, it drives the room pressure stabilization exhaust fan 29 to reduce its own exhaust volume.

[0020] When the local exhaust device 23 stops operating, it outputs a signal (or information) indicating that there is no exhaust to the room pressure stabilization exhaust device 24. Alternatively, when the local exhaust device 23 stops, it outputs a stop signal to the room pressure stabilization exhaust device 24. When the room pressure stabilization exhaust device 24 determines that the exhaust volume of the local exhaust device 23 has decreased based on the acquired signal (or lack of receiving a signal), it drives the room pressure stabilization exhaust fan 29 to increase its own exhaust volume.

[0021] The air conditioning system includes a second equipment 40 that conditions the air in the semi-clean area 12. The second equipment 40 includes a constant air volume control device 41 provided midway through the air supply duct 25 that connects to the air conditioner 21. The constant air volume control device 41 adjusts the air volume so that the room pressure in the semi-clean area 12 is lower than that in the clean area 11. Air supplied from the constant air volume control device 41 via an air supply port 42 returns to the air conditioner 21 via an exhaust port 43 provided in the floor 17 or the like of the semi-clean area 12 and the exhaust duct 28. The amount of exhaust air discharged from the semi-clean area 12 is approximately constant.

[0022] The air conditioning system includes a third equipment 50 that conditions the air in the contaminated area 13. The third equipment 50 has a configuration similar to that of the second equipment 40. A constant air volume control device 51 included in the third equipment 50 adjusts the air volume so that the room pressure in the contaminated area 13 is lower than that in the semi-clean area 12. Air supplied from the constant air volume control device 51 through an air intake port 52 returns to the air conditioner 21 via an exhaust port 53 provided in the floor or the like of the contaminated area 13 and an exhaust duct 28. The amount of exhaust air discharged from the contaminated area 13 is approximately constant.

[0023] (action) The operation of the air conditioning equipment of the food factory 10 will be described below. In the following, the production equipment 15 will be described as an example that is managed at a high temperature.

[0024] The air conditioner 21 supplies conditioned air to the clean area 11, the semi-clean area 12 and the contaminated area 13 via an air supply duct 25. The constant air volume control devices 22, 41, 51 adjust the air volume based on the volume of each zone 11-13 so that the room pressure increases in the order of clean zone 11, semi-clean zone 12, and contaminated zone 13. If a variable air volume control device equipped with a thermostat or the like is installed, the air volume will be adjusted according to the room temperature of each zone 11-13, but the constant air volume control devices 22, 41, 51 stably supply air at a preset volume to each zone 11-13 regardless of the room temperature. A portion of the air in the clean zone 11, semi-clean zone 12, and contaminated zone 13 returns to the air conditioner 21 via the exhaust ports 27, 43, 53 and exhaust duct 28.

[0025] When the local exhaust device 23 starts operating, it outputs the detection result of the exhaust detection sensor or an operation start signal to the room pressure stabilization exhaust device 24. The exhaust volume of the local exhaust device 23 may be constant or variable. When the exhaust volume of the local exhaust device 23 is constant, the room pressure stabilization exhaust device 24 reduces the exhaust volume by the constant exhaust volume discharged by the local exhaust device 23.

[0026] If the exhaust volume of the local exhaust system 23 is variable, the room pressure stabilizing exhaust system 24 determines the exhaust volume based on the acquired signal, etc., and reduces its own exhaust volume by the determined exhaust volume. This prevents the room pressure in the clean area 11 from dropping below the target room pressure.

[0027] When the local exhaust ventilation system 23 stops operating, the room pressure stabilizing exhaust system 24 increases its exhaust volume by the amount of exhaust volume that was being discharged immediately before the local exhaust ventilation system 23 stopped operating. Therefore, it is possible to prevent the room pressure in the clean area 11 from rising above the target room pressure due to the stoppage of the local exhaust ventilation system 23.

[0028] In this way, the constant air volume control devices 22, 41, 51 installed in each of the zones 11 to 13 control the amount of air supply so that the room pressure in each zone 11 is maintained within a target range, while the room pressure stabilizing exhaust device 24 adjusts its own exhaust volume according to the exhaust volume of the local exhaust device 23. This makes it possible to maintain the pressure difference between the room pressure in the clean zone 11 and the room pressure in the adjacent semi-clean zone 12 within a suitable range.

[0029] (Effects of the first embodiment) According to the first embodiment, the following effects can be obtained. (1-1) The room pressure stabilizing exhaust device 24, in conjunction with the operation of the local exhaust device 23 that exhausts the air around the production device 15 or the air inside the production device 15, exhausts air so as to maintain the room pressure in the clean area 11 in a range higher than that of the semi-clean area 12. This makes it possible to suppress fluctuations in the room pressure in the clean area 11.

[0030] Second Embodiment A second embodiment of a factory air conditioning system and its control method will be described. The second embodiment differs from the first embodiment in that a hanging wall is provided between the clean area 11 and the semi-clean area 12. Hereinafter, parts similar to those in the first embodiment will be assigned the same reference numerals and detailed descriptions thereof will be omitted.

[0031] As shown in Figure 2, a hanging wall 61 is provided in the ceiling 14 of the food factory 10 between the clean area 11 and the semi-clean area 12. This hanging wall 61 separates the clean area 11 and the semi-clean area 12.

[0032] In Fig. 2, the horizontal direction in which the clean area 11 and the semi-clean area 12 are aligned is defined as the width direction, and the horizontal direction perpendicular to the width direction is defined as the depth direction. In the example of Fig. 2, all of the walls located between the clean area 11 and the semi-clean area 12 and extending in the depth direction are hanging walls 61, but some of the walls extending in the depth direction may not be hanging walls 61. For example, more than half of the walls extending in the depth direction are hanging walls 61.

[0033] The hanging wall 61 extends downward (vertically) from the ceiling 14. The height of the hanging wall 61 is shorter than the length from the ceiling 14 to the floor 17. Below the hanging wall 61, a transfer opening 62 is defined, through which workers (not shown) move. The workers can move between the clean area 11 and the semi-clean area 12 through the transfer opening 62. The area below the hanging wall 61 is always open when work is being performed in the clean area 11 and the semi-clean area 12.

[0034] (action) The operation of the air conditioning equipment will now be explained. As in the first embodiment, the first equipment 20 maintains the room pressure in the clean area 11 higher than the room pressure in the semi-clean area 12 both when the local exhaust ventilation system 23 is operating and when it is not operating. This creates an airflow that flows from the clean area 11 to the semi-clean area 12, but not the other way around. This prevents foreign matter from entering the clean area 11 from the semi-clean area 12.

[0035] (Effects of the second embodiment) According to the second embodiment, in addition to the effect (1-1) above, the following effect can be obtained. (2-1) The hanging wall 61 secures the transfer opening 62 and creates an air current flowing from the clean area 11 to the semi-clean area 12, thereby preventing foreign matter from entering the clean area 11.

[0036] (Example of change) The above-described embodiments can be modified as follows: The embodiments and the following modifications can be combined with each other within the scope of technical compatibility.

[0037] In the above embodiments, the room pressure stabilization exhaust device 24 reduced the exhaust volume when the local exhaust device 23 started operating. Alternatively, the air supplied to the clean zone 11 may be increased when the local exhaust device 23 started operating. For example, instead of the constant air volume control device 22, a variable air volume control device may be provided in the air supply duct 25. The variable air volume control device controls the air supply volume in conjunction with the local exhaust device 23. That is, the variable air volume control device receives detection results from the exhaust detection sensor from the local exhaust device 23. The variable air volume control device increases the air supply volume to the clean zone 11 when the local exhaust device 23 starts operating, and reduces the air supply volume to be lower than the volume immediately before the local exhaust device 23 stops operating when the local exhaust device 23 stops operating. This embodiment also suppresses fluctuations in room pressure in the clean zone 11.

[0038] If the room pressure in each of the zones 11 to 13 can be maintained within the target range, the constant air volume control devices 22, 41, 51 of the first equipment 20, the second equipment 40, and the third equipment 50 may be changed to variable air volume control devices.

[0039] In each of the above embodiments, the exhaust ports 27, 43, 53 may be provided in the ceiling portion 14, and the intake ports 26, 42, 52 may be provided in the floor. In the second embodiment, a hanging wall 61 is provided between the clean area 11 and the semi-clean area 12, but for example, by providing a hanging wall 61 within the clean area 11, the clean area 11 may be divided into an area where the production equipment 15 is installed and an area where the production equipment 15 is not installed. In the area where the production equipment 15 is installed, a hood 33 connected to an exhaust fan 31 and an exhaust device 24 for stabilizing room pressure are installed. In this case, by further dividing the clean area 11, the local exhaust device 23 can efficiently exhaust heat from the production equipment 15 before the heat is dispersed.

[0040] Next, the technical ideas that can be understood from the above-described embodiments and modifications will be described below. [A] The air conditioning equipment of a factory as described in claim 1, wherein the adjacent area is a semi-clean area having a lower level of hygiene management than the clean area.

[0041] [B] The air conditioning equipment for a factory according to claim 1, wherein the production device is a device for heating food at high temperatures. [Explanation of symbols]

[0042] 10...food factory, 11...clean area, 12...semi-clean area as adjacent area, 15...production equipment, 20...first equipment, 23...local exhaust ventilation system, 40...second equipment.

Claims

1. a first facility for adjusting the room pressure in a clean area in which the production device is installed; A second device that adjusts the room pressure of an adjacent area adjacent to the clean area so that the room pressure is lower than the room pressure of the clean area; a local exhaust device that exhausts air from within the production device or around the production device, The first facility is A factory air conditioning system that, in conjunction with the operation of the local exhaust system, exhausts or supplies air so that the room pressure in the clean area is maintained higher than in the adjacent area.

2. 2. The factory air conditioning equipment according to claim 1, wherein a hanging wall extending vertically from a ceiling portion is provided between the clean area and the adjacent area, and an air current is formed that flows from the clean area to the adjacent area via below the hanging wall.

3. In a method for controlling factory air conditioning equipment, The factory is a clean area where production equipment is installed; a first device for adjusting the room pressure in the clean area; an adjacent area adjacent to the clean area; a second device for adjusting the room pressure in the adjacent area to be lower than the room pressure in the clean area; a local exhaust device that exhausts air from within the production device or around the production device, The first facility, A method for controlling air conditioning equipment in a factory, which exhausts or supplies air in conjunction with the operation of the local exhaust device so that the room pressure in the clean area is maintained higher than in the adjacent area.

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