JP5780892B2 - Air conditioning system - Google Patents

Description

  The present invention relates to an air conditioning system.

  In a relatively large room such as a factory, for example, an air conditioning system 101 as shown in FIG. 8 is used. That is, the indoor unit 102 installed in the room 106 sucks the return air (RA) and the outside air (OA), adjusts it to an appropriate temperature with a refrigerant flowing from an outdoor unit (not shown), and supplies the air into the room (SA). . Then, in a relatively large room such as a factory, in order to supply air to a desired location, for example, as in the air conditioning system 101 shown in FIG. The air is supplied from each air supply port 113 to a desired location.

  In such an air conditioning system 101, since the air supply duct 114 is installed in accordance with the shape of the area that requires air supply, the shape of the area that requires air supply changes due to, for example, a layout change of a production line in a factory. Every time, the air duct 114 needs to be repaired. Duct renovation work takes time, leading to delays in the start of operation of the factory production line.

  Further, in a factory or the like, since the air volume of the exhaust (EA) fan 107 for ventilation is large, the air volume of the air conditioned by the indoor unit tends to be relatively short. That is, since the room is likely to have negative pressure, high temperature and high humidity in summer and low temperature air leaks from the gap and flows in winter, which may increase the air conditioning load and deteriorate the thermal environment. Also, if the air from the indoor unit is blown out so as to stir the room air and disturb the temperature stratification, air close to room temperature is easily exhausted from the ceiling fan etc. is necessary. Furthermore, if the air from the indoor unit is blown out to stir the air in the room, the heat and pollutants generated in the air-conditioning target area are not effectively discharged from the ceiling to the outside. It is necessary to introduce air conditioning energy and fresh outside air.

  In response to such a problem, for example, an air conditioning system 121 as shown in FIG. 9 has been devised. In this air conditioning system 121, an air supply unit 124 is connected to an air supply port of an indoor unit 122 installed in a room 126 by a duct. The air supply unit 124 can adjust the working space near the floor to an appropriate temperature by supplying air at low speed. For example, Patent Documents 1 to 4 disclose details of the air supply unit 124 that performs such low-speed air supply.

  With such an air conditioning system 121, the space near the floor is adjusted to an appropriate temperature by low-speed air supply, so no renovation work is required even if the layout of the production line of the factory is changed, and high temperature and high humidity from the outside. Or even if low-temperature air flows in, the thermal environment in the air-conditioning target area does not deteriorate, and the air near the ceiling in the room is not mixed with the supply air, so that air close to room temperature is not exhausted from the ceiling wastefully. In addition, it is not necessary to introduce more air conditioning energy or fresh outside air for the diffusion of heat and pollutants generated in the air conditioning target area.

Japanese Patent No. 4421347 Japanese Patent No. 4574317 JP 2007-292365 A JP 2007-322049 A

  In such an air conditioning system, when using a commercially available general-purpose packaged air conditioner or the like, the suction wet bulb temperature of the indoor unit is a general upper limit value determined from the viewpoint of preventing high pressure cut (for example, during cooling) It is necessary to use an all-fresh type packaged air conditioner that prevents high-pressure cut in order to prepare for the case of exceeding 24 ° C WB). All-fresh type packaged air conditioners reduce the air flow by about half compared to normal type packaged air conditioners, preventing high pressure cuts. To obtain the cooling capacity and air volume required for indoor air conditioning, double the It is necessary to install indoor units of a certain capacity (number) in the room. For this reason, there is a possibility that the space in the room becomes narrow.

  Further, the air supply port installed above the work space like the air conditioning system 101 in FIG. 8 is provided in the air supply unit 124 installed on the floor in the system configuration like the air conditioning system 121 in FIG. Therefore, there is a possibility that the space in the room becomes narrow.

  Further, if the air supply unit performs low-speed air supply, the thermal environment of the work space can be properly maintained even if the blowout temperature is increased. For this reason, the outside air cooling performed for the purpose of reducing the energy consumed by the cooling can be performed for a longer period than the system configuration like the air conditioning system 101 of FIG. 8, but the cooling capacity and the air volume necessary for the indoor air conditioning are reduced. When the number of indoor units is increased for the purpose of obtaining, the amount of the ducts for taking in outside air increases.

  In addition, when connecting an indoor unit placed on the floor and an air supply unit with a duct routed indoors, it is necessary to start up the duct so that it does not interfere with the production line and passages. The increase in the portion may increase the blast power and increase the energy consumption.

  Furthermore, if the enthalpy of the outside air is higher than the enthalpy of the return air, the damper opening of the amount of return air and the amount of outside air is ensured so as to secure the necessary supply air amount while securing the necessary outside air amount. It is effective to adjust appropriately by adjusting the degree, etc., but dampers corresponding to the number of indoor units are required, which may increase the equipment cost.

  The present application has been made in view of the above matters, and can save labor by reducing the capacity of air-conditioning equipment necessary for air-conditioning while realizing proper air-conditioning even in a space that requires a predetermined amount of ventilation. It is an object to provide an air conditioning system.

  In order to solve the above problems, in the present invention, a plurality of air conditioning indoor units are provided apart from the indoor floor, and the air sent from the air conditioning indoor unit is subjected to temperature stratification indoors by an air supply unit installed on the floor side. It was decided to blow out at a predetermined wind speed. And, on the suction side of each air conditioning indoor unit, an intake duct that guides the return air taken in from the ceiling side of the room and the outside air taken in from the outside is connected, and furthermore, the blowout side and the suction side of the air conditioning indoor unit are When the intake air of the air conditioning indoor unit exceeds the specified upper limit temperature, it is decided to connect a bypass duct provided with a damper that operates in the opening direction.

Specifically, in a replacement ventilation type air conditioning system that supplies air to the indoor floor side, a plurality of air conditioning indoor units provided apart from the indoor floor, and air sent from the air conditioning indoor unit, A plurality of air supply units installed in association with each of the plurality of air-conditioning indoor units on the floor side of the room, which are blown out at a predetermined wind speed at which the temperature stratification in the room is maintained, and taken from the ceiling side of the room The air conditioning indoor unit that connects an intake duct that forms a branch path that guides the return air and outside air taken from outside to the suction side of each of the plurality of air conditioning indoor units, and a discharge side and a suction side of the air conditioning indoor unit And a bypass duct provided with a damper that operates in the opening direction when the intake air exceeds an upper limit temperature defined in the air conditioning indoor unit.

  Here, the air conditioner indoor unit is an air conditioner that harmonizes the air by exchanging heat with the coil in which the refrigerant flows in the pipe. For example, a commercially available ceiling-suspended or ceiling-embedded packaged air conditioner is applied. Can do.

  The air supply unit is a floor-mounted air conditioner that is installed on an indoor floor directly or through a low base, and air conditioned by the air conditioning indoor unit is supplied from a blowout port provided in the air supply unit. It blows out at the wind speed. Here, the predetermined wind speed is a wind speed at which the temperature stratification in the room is maintained. For example, when the air supply unit is not a swirl flow induction type, a slight wind speed of about 0.5 m / s at which the temperature stratification in the room is not disturbed. When the air supply unit is a swirl flow induction type, the wind speed is about 1.2 m / s or less where the temperature stratification in the room is not disturbed. Note that the air supply units do not have to be provided in one-to-one correspondence with one indoor unit. For example, a plurality of air supply units may be connected to one indoor unit. Alternatively, one air supply unit may be connected to a plurality of indoor units.

  In the air conditioning system, the air conditioning indoor unit takes in the return air taken in from the indoor ceiling side and the outside air taken in from the outside from the intake duct, and the air supply unit converts the air conditioned by the air conditioning indoor unit at a predetermined wind speed. By blowing out into the room, pollutants can be transported to the ceiling side while maintaining temperature stratification in the room. The air conditioning indoor unit takes in a part of the air conditioned by the air conditioning indoor unit through the bypass duct, thereby configuring an air conditioning system that performs replacement ventilation even with a standard type air conditioning indoor unit instead of an all-fresh type with a small air volume. be able to. As a result, it is possible to save labor by reducing the capacity of the air-conditioning equipment necessary for air-conditioning while realizing proper air-conditioning even in a space that requires a predetermined amount of ventilation.

  Here, the intake duct has a damper capable of adjusting the amount of the return air and the amount of the outside air guided to the suction side of each air conditioning indoor unit according to the temperature or enthalpy of the return air and the outside air. Further, it may be provided. If such a damper is provided in the intake duct, the amount of return air and the amount of outside air are adjusted by the damper according to the temperature or enthalpy, which is suitable for bringing the air conditioning temperature close to the control target value. Energy consumption required for air conditioning can be reduced.

  In addition, the air conditioning system is configured such that the number of operating air conditioner indoor units connected to a specific air intake duct or an air conditioner outdoor unit that supplies a refrigerant to the air conditioner indoor unit connected to a specific air intake duct according to a heat load processed by the air conditioner indoor unit. Control means for changing the number of operating machines may be further provided.

  In general, the coefficient of performance of an air conditioner is not uniform, and a curve with a specific heat load as a peak is drawn. Therefore, in a system configuration in which there are a plurality of air-conditioning indoor units and air-conditioning indoor units, the energy consumption of the entire air-conditioning system can be reduced by changing the number of operating units in accordance with the thermal load as in the control means. Here, the change in the number of operating units according to the heat load is to increase or decrease the number of operating units so that a plurality of air-conditioning indoor units or air-conditioning outdoor units are operated in a region with a high coefficient of performance. The energy consumption of the air conditioning indoor unit and the outdoor unit compressor is reduced by adjusting the number of operating air conditioning indoor units so that the most efficient heat load is applied to the operating unit.

By controlling the air conditioning system with such control means, it is possible to reduce the energy consumption of the entire system.

  With the air conditioning system described above, it is possible to save labor by reducing the capacity of air conditioning equipment necessary for air conditioning while realizing proper air conditioning even in a space where a predetermined ventilation amount is required.

It is a lineblock diagram of the air-conditioning system concerning an embodiment. It is the figure which showed the driving | running state of all the external air operation mode. It is the figure which showed the driving | running state of the return air cooling operation mode. It is the figure which showed the driving | running state of the heating less operation mode. It is the graph which showed COP of the package air conditioner. It is an operation | movement flowchart in case there are two packaged air conditioners. It is a block diagram of the air conditioning system which concerns on a modification. It is a block diagram of the 1st air conditioning system which concerns on a prior art. It is a block diagram of the 2nd air conditioning system which concerns on a prior art.

  Hereinafter, embodiments of the present invention will be described. The following embodiment shows one aspect of the present invention, and the technical scope of the present invention is not limited to the following embodiment.

  The structure of the air conditioning system which concerns on embodiment is shown in FIG. As shown in FIG. 1, the air conditioning system 1 includes indoor units 2A and 2B, a combined suction chamber 3, air supply units 4A and 4B, and various ducts, and is installed in a room 6 of the building. As shown in FIG. 1, an exhaust fan 7 for ventilating the room 6 is installed on the ceiling of the room 6. However, the exhaust fan 7 is omitted if the possibility of air contamination in the room 6 is low. May be. A plurality of systems including the indoor units 2 </ b> A and 2 </ b> B and the air supply units 4 </ b> A and 4 </ b> B connected to one dual-purpose suction chamber 3 may be installed in the room 6. The exhaust fan 7 may be individually provided with a power switch or an inverter device that increases or decreases the rotational speed of the fan so that the exhaust amount can be appropriately changed according to seasonal fluctuations throughout the year, the contamination state of the room 6, and the like. Good. In addition, the description of the following driving | operation aspect is a thing at the time of air_conditioning unless there is a notice.

  The indoor units 2A and 2B are ceiling-suspended standard indoor units, and general products widely distributed in the market of air conditioners can be applied. However, the wet bulb upper limit temperature of the intake air of the standard type indoor unit is lower (narrower) than, for example, 24 ° C. WB and the all fresh type. For this reason, in this air conditioning system 1, the indoor unit 2A, 2B partially sucks the air blown from the indoor unit 2 so that the wet bulb temperature of the intake air of the indoor units 2A, 2B is less than the wet bulb upper limit temperature. Ducts 8A and 8B are provided. Bypass duct 8A, 8B forms the path | route which bypasses the room | chamber 6 by directly connecting the blowing side and suction side of indoor unit 2A, 2B. The air volume that can flow through the bypass ducts 8A and 8B depends on the thermal environment of the room 6, but is approximately 20% of the rated air volume of the indoor units 2A and 2B, the indoor units 2A and 2B. It is possible to control so that the wet bulb temperature of the intake air does not exceed the wet bulb upper limit temperature.

  In the case of an all-fresh type packaged air conditioner, the supply air amount is about one-half to one-third that of a standard type packaged air-conditioner in order to guarantee the blowing temperature even at extremely low or high temperature outside air. is there. However, in the case of a standard type indoor unit such as the indoor units 2A and 2B, a sufficient supply amount can be obtained when the wet bulb temperature of the intake air is low, and the wet bulb temperature of the intake air Therefore, even if a part of the air supply is allowed to flow through the bypass ducts 8A and 8B, a sufficient air supply amount can be secured as compared with the all fresh type.

  The indoor units 2 </ b> A and 2 </ b> B are connected to the combined suction chamber 3, and suck the outside air (OA) and the return air (RA) through the intake duct 9 and the combined suction chamber 3. Then, the sucked air is adjusted to an appropriate temperature with a refrigerant flowing from an unshown outdoor unit, and the temperature-adjusted air is sent to the air supply units 4A and 4B. The outdoor unit is provided outdoors or in a machine room communicating with the outside, and one unit (multi-system) is provided corresponding to the indoor units 2A and 2B or in common. In the indoor units 2A and 2B, the rotation speed of the fan in the unit, the opening degree of the expansion valve, the compression of the outdoor unit are performed so that the measured value (room temperature) of the temperature sensor 10 provided in the room 6 becomes the control target value (set temperature). The room 6 is air-conditioned by adjusting the number of revolutions of the machine. Note that the indoor units 2A and 2B are not necessarily those that control the room temperature based on the temperature sensor 10 provided in the room 6, but for example, any of the air supply paths between the outlet of the indoor unit and the air supply unit. It may operate so that the measured value (supply air temperature) of the temperature sensor provided at such a point becomes the control target value (set temperature) to control the supply air temperature.

The intake duct 9, the damper 11 _-OA and adjusting the amount of outside air, the damper 11 _-RA to adjust the amount of return air is provided. Damper 11 _-OA, 11 _-RA may be any so long as it can be adjusted to an appropriate degree, but it is easy to electronic control by the control device by using the motor-damping.

The intake duct 9, the sensor 12 _-OA or for measuring the outside air temperature and humidity, the sensor 12 _-RA for measuring the temperature and humidity of the return air are provided. The sensor 12 _-OA or sensor 12 _-RA is not necessarily limited to those which measure both the temperature and humidity, for example, may be configured to measure the temperature only.

Further, the bypass ducts 8A, 8B are provided with dampers 11A- _BP , 11B- _BP for adjusting the amount of air returning from the blow-out side of the indoor units 2A, 2B to the suction side. The dampers 11A- _BP and 11B- _BP may be any one that can be adjusted to an appropriate opening degree, similarly to the dampers 11- _OA and 11- _RA. Electronic control by the device is easy. The dampers 11A- _BP and 11B- _BP appropriately adjust the amount of air returning from the blow-out side of the indoor units 2A and 2B to the suction side so that the wet-bulb temperature of the intake air of the indoor units 2A and 2B does not exceed the wet bulb upper limit temperature. Adjust to. The airflow flowing through the bypass ducts 8A and 8B from the blow-out side of the indoor units 2A and 2B to the suction side is formed by the negative of the suction side and the positive side of the blow-out side by the fan of the indoor unit. The airflow flowing from the blow-out side of the indoor units 2A and 2B to the suction side is separated from the indoor unit, for example, on the downstream side of the junction of the bypass ducts 8A and 8B and the intake duct 9, for example, in the combined suction chamber 3 It may be formed by a fan installed in front or inside.

  The air supply units 4A and 4B are swirl flow induction type air supply units that supply air to the room 6 while attracting the surrounding air by the swirl flow, and are provided with fins that are inclined to give a swirl component to the air. A large number of air supply ports are arranged vertically and horizontally so that the inclination directions of the fins are opposite to each other. In this way, by providing the air supply ports so that the air swirl directions are alternated, the swirl components of the air blown from the air supply ports are not canceled out, and the swirl motions are promoted. As the air blows out from the air supply port while being swirled, the amount of attracting ambient air to be attracted increases more than in the case of non-swirling, the air supply speed is quickly attenuated, and the draft feeling without disturbing the air flow in the room 6 Realizes low-speed air supply with little.

In a system that performs displacement ventilation, it is important not to disturb the temperature stratification in the room. In the air conditioning system 1 as well, air supplied from the indoor units 2A and 2B is supplied so as not to disturb the temperature stratification in the room 6. Air is supplied at low speed by the units 4A and 4B. In general, in the case of a swirl flow induction type air supply unit, if air is supplied so that the wind speed at the outlet is less than or equal to about 1.2 m / s, the temperature stratification is less likely to be disturbed. The selection of the air supply units 4A and 4B and the indoor units 2A and 2B is made to follow this. If the air supply unit is not a swirl flow induction type, temperature stratification is unlikely to be disturbed if air is supplied so that the wind speed is about 0.5 m / s or less.

Further, dampers 11A- _CD , 11B- _CD for preventing backflow of air are provided in the middle of the duct connecting the indoor units 2A, 2B and the air supply units 4A, 4B. When any one of the indoor units stops, air is prevented from flowing backward through the stopped indoor unit. The dampers 11A- _CD and 11B- _CD may be check dampers, motor dampers that open and close according to the operating state of the indoor unit, cylinder dampers that open and close by hydraulic pressure or air pressure, and the like. .

  In this embodiment, the two indoor units 2A and 2B are connected to the dual-purpose suction chamber 3, and the air supply units 4A and 4B are connected to the indoor units 2A and 2B, but the air supply unit is one indoor unit. Need not be provided in one-to-one correspondence with each other, and the combined suction chamber 3 may be connected to one indoor unit or three or more indoor units. A plurality of air supply units may be connected, or one air supply unit may be connected to a plurality of indoor units. When one air supply unit is connected to a plurality of indoor units, for example, the interior of the air supply unit is divided into a plurality of parts by movable dampers or partition members, and each air supply is associated with each compartment. Make sure the unit is connected. For example, if the air supply unit is formed in a rectangular shape when viewed from above and blows in four directions, the inside of the air supply unit is divided into four sections by dampers at the four corners, and the air supply unit is divided into each section. By connecting, it becomes possible to connect four indoor units to one air supply unit.

  Further, the suction port for sucking the return air and the air supply ports of the air supply units 4A and 4B may be in any planar position as long as the room 6 can be effectively air-conditioned. If the height of the ceiling of the air supply port is set to be higher than one half of the ceiling height of 6 and the upper end of the air supply port is set to a height lower than one half of the ceiling height of the room 6, the air supply units 4A and 4B Since the warm air raised by the low-temperature air blown out is sucked into the suction port, the room 6 can be efficiently air-conditioned.

  Note that the suction port may be higher than the living area. When the indoor units 2A and 2B are installed at a height higher than the living area, the intake duct 9 is not provided with a return air duct. The dual-purpose suction chamber may be provided with a return air suction port with a damper, or the return air may be directly sucked from an opening (with a damper) on the back of the indoor units 2A and 2B.

  With the air conditioning system 1 configured as described above, a standard type package air conditioner for embedding the ceiling or hanging the ceiling can be used without using an all fresh type with a small air volume, and a duct on the supply side can be used. In order to share the system, a system can be constructed with a smaller number of indoor units and capacity, a smaller amount of ducts, and a smaller number of dampers. As a result, facility costs and maintenance costs can be greatly reduced, and energy-saving operation throughout the year can be realized. In addition, when adopting replacement ventilation, the number of equipment installed on the floor can be reduced, and the area that can be used indoors can be increased. In addition, thermal comfort and air cleanliness can be improved while realizing energy saving operation throughout the year. Furthermore, since the air conditioning system 1 accumulates cold air in the air conditioning target area, for example, duct refurbishment work associated with a change in the layout of a factory production line or the like becomes unnecessary.

  In addition, the said air conditioning system 1 can be drive | operated as follows, for example except the cooling operation mentioned above.

<All outside air operation mode>
When the outside air enthalpy is less than or equal to the return air enthalpy (OA enthalpy ≤ RA enthalpy)
In the case of the air conditioning system 1 recommended when the outside air temperature is equal to or higher than a predetermined temperature set in advance (hereinafter referred to as “minimum outside air set temperature”, for example, 5 ° C.), for example, outside air temperature ≧ minimum outside air set temperature). FIG. 2 shows the operation state (referred to as “all outside air operation mode” in this application).

The air conditioning system 1 in the all-outside air operation mode fully _opens the damper 11- _OA , fully closes the damper 11- _RA , and _causes the indoor units 2A and 2B to perform the air blowing operation. Further, all the exhaust fans 7 are operated so that an air volume capable of sufficiently discharging hot air near the ceiling of the room 6 is obtained (when an inverter device is provided, the maximum output is set). Even when the indoor units 2A and 2B are in the air blowing operation, the temperature of the air-conditioning target area can be adjusted to the set temperature or less, and the outdoor unit can be turned off to reduce unnecessary standby power during periods when the outdoor unit is not required to operate. desirable.

  If the temperature of the air-conditioning target area becomes higher than the set temperature even when the indoor units 2A and 2B are blown, the outdoor unit is activated and the indoor units 2A and 2B are placed in the cooling operation. In the all outside air operation mode, the enthalpy of the outside air is equal to or less than the enthalpy of the return air. Therefore, even if the indoor units 2A and 2B are in the cooling operation, cooling can be performed with less energy than the “return air cooling operation mode” described later.

  In the air conditioning system 1, since the indoor units 2A and 2B are standard packaged air conditioners, the air supply units 4A and 4B have a sufficient air volume compared to the all fresh type packaged air conditioners, and the work space Can maintain the thermal environment properly. Therefore, the operation in the “all outside air operation mode” performed for the purpose of reducing consumed energy can be performed for a longer time than the air conditioning system 101 as shown in FIG.

<Return air cooling operation mode>
FIG. 3 shows an operation state of the air conditioning system 1 recommended when the outside air enthalpy is higher than the return air enthalpy (hereinafter referred to as “return air cooling operation mode”).

Air conditioning system 1 of the return air cooling operation mode, the opening degree of the damper 11 _-OA can ensure the minimum amount of outside air, and a damper 11 _-RA fully opened to the indoor unit 2A, and 2B in the blowing operation. Here, the minimum amount of outside air is the amount of outside air necessary to eliminate pollutants in the air-conditioning target area, and is an amount that is appropriately determined according to the amount of pollutants generated and the required cleanliness. Further, the exhaust fan 7 is operated from the outside by reducing the number of operating units so that the room pressure becomes appropriate (when the inverter device is provided, reducing the output so that the room pressure becomes appropriate). Reduce the amount of outside air entering the room. If the airtightness is low and there is a lot of air leaking from the outside to the room (hereinafter referred to as “leakage”), the enthalpy of the return air can be reduced by limiting the operation of the exhaust fan 7 and reducing the amount of exhaust air. However, when the amount of pollutants such as oil mist generated in the room 6 is large, it is desirable that the number of ventilations in the room 6 be an appropriate number (for example, 0.5 times / h) or more.

  If the temperature of the air-conditioning target area may be higher than the set temperature even when the indoor units 2A and 2B are in the air blowing operation, the outdoor unit is activated and the indoor units 2A and 2B can be in a cooling operation state. To do.

<Heating-less and heating operation mode>
When the outside air temperature is lower than the minimum outside air set temperature (outside air temperature <minimum outside air set temperature), the outside air temperature is low, and the temperature of the air-conditioning target area is equal to or lower than the first lower limit temperature (for example, 18 ° C.) in the all outside air operation mode described above. FIG. 4 shows the recommended operating state of the air conditioning system 1 in this case (referred to as “heatingless operation mode” in the present application).

Air conditioning system 1 of the heating-less operation mode, controls the damper 11 _-OA the opening and the damper 11 the ratio of _-RA opening as the work area of the chamber 6 becomes proper temperature, the indoor unit 2A, and 2B Set to blow operation. Since the air supply speeds of the air supply units 4 </ b> A and 4 </ b> B are moderate, relatively hot air tends to gather at the upper part of the room 6. Therefore, by mixing the return air having a relatively high temperature and the outside air having a relatively low temperature in an appropriate ratio and supplying the air from the air supply units 4A and 4B, the working area of the room 6 is brought to an appropriate temperature to some extent. can do.

  The exhaust fan 7 is operated by reducing the number of operating units so that the room pressure is appropriate (when an inverter device is provided, the output is reduced so that the room pressure is appropriate), and from the outside to the room. Reduce the amount of outside air entering. If there is a lot of air leakage, the operation of the exhaust fan 7 is restricted to reduce the amount of exhaust air, so that the entry of relatively cool outside air can be suppressed. In general, many factories generate a lot of heat from the machinery in the room 6, so by reducing the amount of air leakage in the winter, heating in the winter is not required except during the start-up period until the room 6 is sufficiently warmed up. Can be. However, when the amount of pollutants such as oil mist generated in the room 6 is large, it is desirable that the number of ventilations in the room 6 be an appropriate number (for example, 0.5 times / h) or more.

Further, when the outside air temperature is lower than the minimum outside air set temperature (outside air temperature <minimum outside air set temperature), the outside air temperature is low, and the temperature of the air-conditioning target area is lower than the first lower limit temperature in the all outside air operation mode described above. The recommended operating state of the air conditioning system 1 when the temperature is lower than the lower limit temperature (for example, 16 ° C.) (referred to as “heating operation mode” in the present application) is the damper 11 ₋ so that the working area of the room 6 becomes an appropriate temperature. _While restricting _OA to an opening that can secure the minimum amount of outside air, the damper 11 _{-RA is set} to an opening that can secure the supply air volume, and the indoor units 2A and 2B are set to the heating operation.

  By operating the air conditioning system 1 in this way, efficient operation of the air conditioning system can be realized throughout the year. Each operation mode described above may be automatically switched by the control device, or may be switched manually. In the case of a control device, sensors that can electrically measure enthalpy are provided. Such air conditioning control may be realized by temperature instead of enthalpy.

  Note that the number of operating indoor units can be determined as follows, for example. As shown in FIG. 5, it is known that the package air conditioner has a COP (coefficient of performance) that changes according to the load factor, and that the COP extremely decreases as the load factor decreases. Therefore, by measuring the supply / exhaust temperature difference of each packaged air conditioner or the current value (or electric energy), the load factor is grasped, and when the load factor is small and COP deteriorates, the number of packaged air conditioners is reduced. Improving the COP of the driver is effective for energy saving. When carrying out the operation with a reduced number of operating units, it is desirable to appropriately change the opening degree of the damper for introducing the outside air and the opening degree of the damper for introducing the return air so as to ensure the minimum amount of outside air. The supply / exhaust temperature difference can be calculated, for example, by measuring the supply air temperature and the intake temperature with the combined intake chamber 3 and the intake unit 4.

  FIG. 6 is an operation flowchart when there are two packaged air conditioners. In FIG. 6, when the temperature difference becomes 5 ° C. or less, for example, one indoor unit is stopped and one unit is operated, and when the supply / exhaust temperature difference becomes 10 ° C. or more, it is returned to the two-unit operation. Is illustrated. That is, immediately after the air-conditioning system 1 is started, since the temperature difference between the supply and exhaust air is large, two indoor units are operated (S101). However, if the two-unit operation continues, the supply / exhaust temperature difference will eventually become smaller, for example, 5 ° C. or less (S102). Then, one indoor unit is stopped and one unit is operated (S103). Here, when the heat load increases, the temperature difference between the supply and exhaust air becomes large during operation of one indoor unit, for example, exceeding 10 ° C. (S104). Then, the stopped indoor unit is activated and two units are operated (S101).

The control of the number of operating units using the supply / exhaust temperature difference may be such that the load factor is grasped from the operating current value of the compressor of the outdoor unit and the number of operating units is changed based on this. In this case, for example, if the load factor of the compressor is 30% or less, the number of operating units is reduced to one unit operation. For example, if the load factor becomes 90% or more, one unit operation is returned to two unit operation. Good. When two indoor units are installed, if each indoor unit is operated in this way, the COP of the operating unit is improved, which is effective for energy saving. In the case of changing the number of operating indoor units, changing the opening of the damper 11 _-OA or damper 11 _-RA appropriate.

  Such a change in the number of operating units and the adjustment of the damper accompanying the change in the number of operating units may be controlled automatically by the control device or may be controlled manually. Regarding the operation of the outdoor unit, when the indoor unit and the outdoor unit are one-to-one, the outdoor unit also stops in conjunction with the stop of the indoor unit, and one outdoor unit is provided for a plurality of indoor units. In the case of a multi system, the outdoor unit compressor is operated at a reduced speed.

  In the embodiment described above, the two indoor units 2 </ b> A and 2 </ b> B are connected to the dual-purpose suction chamber 3. However, three or more indoor units may be connected to the combined suction chamber 3. For example, a modification example in which four indoor units are connected to the dual-purpose suction chamber is shown below.

  The figure which looked at the air conditioning system 21 which concerns on the modification of the said embodiment from the top is shown in FIG. As shown in FIG. 7, in the air conditioning system 21 according to this modification, four indoor units 22 </ b> A, 22 </ b> B, 22 </ b> C, and 22 </ b> D are attached to the dual-purpose suction chamber 3 in four directions. Further, bypass ducts 28A, 28B, 28C, 28D are provided between the intake duct 29 and the blowout side of each indoor unit 22A, 22, B, 22C, 22D. Airflow from the blow-out side to the suction side of each indoor unit 22A, 22B, 22C, 22D flowing through each bypass duct 28A, 28B, 28C, 28D is formed by the fan of each indoor unit 22A, 22B, 22C, 22D. Air supply units 24A, 24B, 24C, and 24D are connected to the indoor units 22A, 22B, 22C, and 22D. Each of the air supply units 24A, 24B, 24C, and 24D is installed so as to face each other such that the air supply ports face outward. In FIG. 7, the return air intake port is installed on the air supply unit 24 </ b> A side of the intake duct 29, but the return air intake port can be directed in any direction. Further, the airflow from the blow-out side to the suction side of each indoor unit 22A, 22B, 22C, 22D flowing through each bypass duct 28A, 28B, 28C, 28D is formed by the fan of each indoor unit 22A, 22B, 22C, 22D. However, this air flow is installed separately from the indoor unit, downstream of the junction of the bypass ducts 28A, 28B, 28C, 28D and the intake duct 29, for example, before or inside the combined suction chamber 23. You may form with a fan.

  Moreover, although each indoor unit of the air conditioning system which concerns on the said embodiment and modification may be made to hang from a ceiling, you may make it support using the stand installed in the floor, for example. In rooms with high ceiling height, there is no need to install long suspension bolts to suspend the indoor unit, and by installing the indoor unit at a height that allows for maintenance, a maintenance inspection walkway can be omitted. . Moreover, you may take in external air from the gallery provided in the building. Further, the air supply unit is not limited to being installed on the floor, and may be installed on a wall or the like.

1, 2, 101, 121 ··· Air conditioning systems 2A, 2B, 22A, 22B, 22C, 22D, 102, 122 · · Indoor units 3, 23 ··· Combined suction chambers 4A, 4B, 24A, 24B, 24C, 24D, 124 ... air supply unit 6,106,126 .. indoor 7,107 · exhaust fan 8A, 8B, 28A, 28B, 28C, 28D ·· bypass duct 9, 29 .. intake duct 10 ... temperature sensor 11 _{- OA} , 11- _RA , 11A- _BP , 11B- _BP , 11A- _CD , 11B- _CD, damper 12- _OA , 12- _RA, sensor 113, air inlet 114, air duct

Claims (3)

It is a replacement ventilation type air conditioning system that supplies air from the ceiling side to the indoor floor side ventilated by an exhaust fan ,
A plurality of air conditioning indoor units provided in the indoor space apart from the indoor floor and ceiling ;
A plurality of air supply units installed in association with each of the plurality of air conditioner indoor units on the floor side of the room, which blows out air sent from the air conditioner indoor unit at a predetermined wind speed at which temperature stratification in the room is maintained. When,
An intake duct that forms a branch path that guides the return air taken from the ceiling side of the room and the outside air taken from the outside to the suction side of each of the plurality of air conditioning indoor units;
A bypass duct connecting a blow-out side and a suction side of the air-conditioning indoor unit, provided with a damper that operates in an opening direction when intake air of the air-conditioning indoor unit exceeds an upper limit temperature defined in the air-conditioning indoor unit; Comprising
Air conditioning system. The intake duct is further provided with a damper capable of adjusting the amount of the return air and the amount of the outside air guided to the suction side of each air conditioning indoor unit according to the temperature of the return air and the outside air or enthalpy. ing,
The air conditioning system according to claim 1. Depending on the heat load processed by the air conditioning indoor unit, the number of operating air conditioning indoor units connected to a specific air intake duct or the number of operating air conditioning outdoor units supplying refrigerant to the air conditioning indoor unit connected to a specific air intake duct is changed. Further comprising a control means,
The air conditioning system according to claim 1 or 2.

Images