WO2024095444A1

WO2024095444A1 - Air conditioning system

Info

Publication number: WO2024095444A1
Application number: PCT/JP2022/041151
Authority: WO
Inventors: 勇人堀江; 芸青范
Original assignee: 三菱電機株式会社
Priority date: 2022-11-04
Filing date: 2022-11-04
Publication date: 2024-05-10

Abstract

Provided is an air conditioning system that provides air conditioning to improve user comfort in a space to be air conditioned, the air conditioning system comprising a first air conditioner, a first ventilation device, a first inlet temperature sensor, a return air temperature sensor, and a control device. The first air conditioner air conditions a first area in the space to be air conditioned. The first ventilation device ventilates the first area. The first inlet temperature sensor obtains a first inlet temperature, which is the temperature of air that the first air conditioner draws in from the first area. The return air temperature sensor obtains a return air temperature, which is the temperature of air that the first ventilation device draws in from the first area. The control device corrects the first inlet temperature on the basis of the return air temperature and controls the first air conditioner to provide air conditioning on the basis of the corrected first inlet temperature.

Description

Air Conditioning System

This disclosure relates to an air conditioning system having a ventilation device and an air conditioner.

　Conventionally, there has been known an air conditioning system that has an air conditioner and a ventilation device installed in the same space to be air-conditioned (see, for example, Patent Document 1). The ventilation device ventilates the room by exchanging the air in the room, which is the space to be air-conditioned, with outside air, and the air conditioner adjusts the temperature in the room.

International Publication No. 2018/220803

Here, by installing the ventilation device and the air conditioner in the same space to be air-conditioned, there is a possibility that the air conditioner will directly suck in the air blown out from the ventilation device. In other words, there is a possibility that the air conditioner will suck in air that flows out from the ventilation device and has a temperature that is the same as the outdoor air temperature. This phenomenon can occur, for example, when the concentration of carbon dioxide in the room is high and the ventilation device increases the ventilation air volume. In this case, energy is wasted by performing air conditioning operation based on the temperature of the air sucked in by the air conditioner. For example, in the summer, when the ventilation device supplies high-temperature outdoor air to the room during cooling operation, the air conditioner may suck in high-temperature air from the ventilation device. Then, even if the air in the room is cooled by cooling operation, the air conditioner cools the room more than necessary because it performs air conditioning so that the high-temperature air from the ventilation device approaches the set temperature. As a result, energy is wasted.

The present disclosure has been made to solve the above problems, and aims to provide an air conditioning system that reduces unnecessary energy consumption by the air conditioner, which can occur when air that has flowed out from the ventilation device is sucked in.

The air conditioning system according to the present disclosure includes a first air conditioner that conditions a first area in a space to be air-conditioned, a first ventilation device that ventilates the first area, a first intake temperature sensor that acquires a first intake temperature, which is the temperature of the air that the first air conditioner draws in from the first area, a return air temperature sensor that acquires a return air temperature, which is the temperature of the air that the first ventilation device draws in from the first area, and a control device that controls the first ventilation device and the first air conditioner, and the control device corrects the first intake temperature based on the return air temperature and controls the first air conditioner to perform air conditioning based on the corrected first intake temperature.

In the air conditioning system disclosed herein, the control device corrects the first intake temperature acquired by the first intake temperature sensor based on the return air temperature. As a result, even if air of a temperature equivalent to the outside air temperature blown out from the first ventilation device is sucked into the first air conditioner, the corrected first intake temperature is closer to the temperature of the first area than the first intake temperature before correction, and the first air conditioner is able to perform air conditioning based on the more accurate first intake temperature as the temperature of the first area. Therefore, in cooling operation, the temperature of the first area does not drop too much below the set temperature, and in heating operation, the temperature of the first area does not rise too much above the set temperature, suppressing wasteful energy consumption.

1 is a schematic diagram illustrating an air conditioning system according to a first embodiment; FIG. 2 is a diagram illustrating a first installation example of a plurality of air conditioners and one or more ventilators in the first embodiment. FIG. 10 is a diagram illustrating a second installation example of a plurality of air conditioners and one or more ventilators in the first embodiment. 10 is a diagram for explaining a method of determining a first correction coefficient based on a ventilation air volume in the first embodiment. FIG. 10 is a diagram for explaining a method of determining a first correction coefficient based on an outside air set temperature difference in the first embodiment. FIG. 2 is a block diagram illustrating a hardware configuration of a control device according to the first embodiment. FIG. 4 is a flowchart illustrating a flow of an air conditioning process by the air conditioning system according to the first embodiment. 10 is a flowchart illustrating a flow of an air conditioning process by an air conditioning system according to a second embodiment.

The air conditioning system according to the first embodiment will be described in detail below with reference to the drawings.

Embodiment 1.
1 is a schematic diagram illustrating an air conditioning system 100 according to embodiment 1. The air conditioning system 100 performs air conditioning and ventilation in a room, which is a space to be air-conditioned. The air conditioning system 100 includes one or more air conditioners 1, one or more carbon dioxide sensors 2, one or more ventilators 3, one or more outdoor air temperature sensors 4, and a control device 5. The one or more air conditioners 1, the one or more carbon dioxide sensors 2, and the one or more ventilators 3 are installed in the space to be air-conditioned.

The one or more air conditioners 1 have a heat exchanger (not shown). The one or more air conditioners 1 are also provided with one or more heat source units (not shown). The one or more heat source units draw in outside air, exchange heat between the outside air and a refrigerant, and supply the refrigerant after heat exchange to the one or more air conditioners 1. The one or more air conditioners 1 then draw in indoor air, exchange heat with the refrigerant from the one or more heat source units in the heat exchanger, and send the air after heat exchange into the room, thereby performing air conditioning. Note that the one or more heat source units may exchange heat between the refrigerant that has exchanged heat with outside air or the like and a heat medium, and supply the heat medium after heat exchange to the one or more air conditioners 1. In this case, the one or more air conditioners 1 exchange heat with the heat medium in the heat exchanger with the drawn-in air, and send the air after heat exchange into the room.

The air conditioner 1 is provided with an air conditioning intake temperature sensor 10 upstream of the heat exchanger to acquire the temperature of the air drawn in from inside the room. That is, the air conditioning intake temperature sensor 10 acquires the temperature of the air drawn into the air conditioner 1 and before heat exchange in the heat exchanger. Note that when the air conditioning system 100 includes multiple air conditioners 1, each air conditioner 1 is provided with an air conditioning intake temperature sensor 10. The temperature of the air drawn into the air conditioner 1 and acquired by the air conditioning intake temperature sensor 10 may hereinafter be referred to as the intake temperature.

The one or more carbon dioxide sensors 2 acquire the concentration of carbon dioxide in the room. Hereinafter, the concentration of carbon dioxide in the room may be referred to as the carbon dioxide concentration. Here, the one or more carbon dioxide sensors 2 may be fixed in the room or may be portable by a person.

The one or more ventilation devices 3 ventilate the room based on the carbon dioxide concentration acquired by the one or more carbon dioxide sensors 2. Here, the one or more ventilation devices 3 ventilate the room by replacing the air outside with the air inside. For this reason, the ventilation device 3 is provided with an exhaust air duct 3A for circulating the sucked air inside the room to the outside, and an air supply duct 3B for circulating the sucked air inside the room. In FIG. 1, the exhaust air duct 3A is indicated by a dashed arrow, and the air supply duct 3B is indicated by a solid arrow. Note that when the air conditioning system 100 is provided with multiple ventilation devices 3, each ventilation device 3 is provided with an exhaust air duct 3A and an air supply duct 3B.

The ventilation device 3 is provided with a return air temperature sensor 30 that acquires the temperature of the air sucked in from inside the room. The return air temperature sensor 30 is installed on the exhaust air duct 3A. If the air conditioning system 100 is equipped with multiple ventilators 3, the return air temperature sensor 30 is installed on the exhaust air duct 3A of each ventilator 3. The temperature of the air sucked into the ventilation device 3 and acquired by the return air temperature sensor 30 may be referred to as the return air temperature below.

FIG. 1 shows an example of a ventilation device 3 having a total heat exchanger 31 that exchanges heat between air sent from inside the room to outside the room and air sent from outside the room to inside the room, but the ventilation device 3 does not have to have a total heat exchanger 31. If the ventilation device 3 has a total heat exchanger 31, the return air temperature sensor 30 is installed upstream of the total heat exchanger 31 in the exhaust air duct 3A.

The one or more outdoor air temperature sensors 4 acquire the outdoor air temperature, which is the temperature of the air outside. The one or more outdoor air temperature sensors 4 may be provided in one or more ventilation devices 3 or one or more air conditioners 1. If the air conditioning system 100 includes multiple ventilation devices 3, the outdoor air temperature sensor 4 may be provided on the supply air duct 3B of at least one ventilation device 3, or at the inlet of the supply air duct 3B. If the air conditioning system 100 includes one ventilation device 3, the outdoor air temperature sensor 4 may be provided on the supply air duct 3B of the one ventilation device 3 and/or at the air inlet to the supply air duct 3B. Note that when one or more outdoor air temperature sensors 4 are provided in one or more ventilation devices 3, and when the one or more ventilation devices 3 have a total heat exchanger 31, the one or more outdoor air temperature sensors 4 are provided upstream of the total heat exchanger 31.

The one or more outdoor air temperature sensors 4 may be provided in one or more heat source units. In this case, if the air conditioning system 100 includes one heat source unit, the outdoor air temperature sensor 4 is provided in the intake port of the one heat source unit through which the heat source unit draws in outdoor air. Alternatively, if the air conditioning system 100 includes multiple heat source units, the outdoor air temperature sensor 4 is provided in the intake port of at least one heat source unit. The one or more outdoor air temperature sensors 4 may be installed outdoors, outside one or more ventilators 3, and outside one or more heat source units.

The control device 5 controls one or more air conditioners 1 and one or more ventilation devices 3. More specifically, the control device 5 acquires the suction temperature from one or more air conditioning suction temperature sensors 10, and controls the temperature of air blown into the room from one or more air conditioners 1 based on the suction temperature. The control device 5 controls the temperature of air blown into the room from one or more air conditioners 1 by controlling the operating frequency of a compressor (not shown) and the opening degree of an expansion valve (not shown) provided in one or more air conditioners 1. The control device 5 acquires the carbon dioxide concentration from one or more carbon dioxide sensors 2, and controls one or more ventilation devices 3 based on the carbon dioxide concentration.

1 shows an example in which the control device 5 is provided separately from the air conditioner 1 and the ventilation device 3, but the control device 5 may be provided integrally with one or more air conditioners 1 or one or more ventilation devices 3. Alternatively, a part of the control device 5 may be provided in one or more air conditioners 1, and another part may be provided in one or more ventilation devices 3. More specifically, all or a part of the control device 5 may be provided in the housing of one air conditioner 1, or, if the air conditioning system 100 includes multiple air conditioners 1, it may be provided separately in each housing of two or more air conditioners 1. Also, all or a part of the control device 5 may be provided in the housing of one ventilation device 3, or, if the air conditioning system 100 includes multiple ventilation devices 3, it may be provided separately in each housing of two or more ventilation devices 3. If the control device 5 is provided in a separate state, each part of the control device 5 exchanges information with each other by wired communication or wireless communication.

When the air conditioning system 100 is equipped with multiple air conditioners 1, the room is divided into multiple regions, and each air conditioner 1 conditions each region. Below, with reference to Figures 2 and 3, an installation example of multiple air conditioners 1 in embodiment 1 will be described. Figure 2 is a diagram that shows a schematic diagram of a first installation example of multiple air conditioners 1 and one or more ventilation devices 3 in embodiment 1. Figure 3 is a diagram that shows a schematic diagram of a second installation example of multiple air conditioners 1 and one or more ventilation devices 3 in embodiment 1. In Figures 2 and 3, each region is shown by a rectangle drawn with dashed lines. In Figures 2 and 3, the space to be air-conditioned is divided into four regions. In Figures 2 and 3, an air conditioner 1 is installed in each region. In Figure 2, each of the four ventilation devices 3 is installed to ventilate each of the four regions.

On the other hand, in FIG. 3, two ventilation devices 3 are installed so that each of them ventilates two of the four areas. That is, one of the two ventilation devices 3 ventilates two of the four areas, and the other ventilates two areas other than the two areas ventilated by the other. Two ducts 32 are connected to each ventilation device 3. One of the two ducts 32 communicates with the exhaust air duct 3A of the ventilation device 3, and the other communicates with the supply air duct 3B. Hereinafter, the duct 32 communicating with the exhaust air duct 3A may be referred to as the exhaust duct 32A, and the duct 32 communicating with the supply air duct 3B may be referred to as the supply air duct 32B. The return air temperature sensor 30 may be provided in the exhaust duct 32A instead of the exhaust air duct 3A in the ventilation device 3.

Each of the exhaust duct 32A and the supply air duct 32B is formed in a fork shape. In the example shown in FIG. 3, each of the exhaust duct 32A and the supply air duct 32B is formed in a bifurcated shape. Note that in FIG. 3, the exhaust duct 32A is shown by a bifurcated dashed line with one end connected to the ventilation device 3, and the supply air duct 32B is shown by a bifurcated solid line with one end connected to the ventilation device 3.

Each of the multiple ends of the exhaust duct 32A opposite the end connected to the ventilation device 3 is provided with an exhaust port that draws in air from inside the room. The multiple exhaust ports of the exhaust duct 32A are arranged in each of the multiple areas. In detail, each of the multiple exhaust ports of the exhaust duct 32A is arranged in each of the multiple areas ventilated by the ventilation device 3 to which the exhaust duct 32A is connected.

Each of the multiple ends of the air supply duct 32B opposite the end connected to the ventilation device 3 is provided with an air supply port that blows air into the room. The multiple air supply ports of the air supply duct 32B are arranged in each of the multiple areas. In detail, each of the multiple air supply ports of the air supply duct 32B is arranged in each of the multiple areas ventilated by the ventilation device 3 to which the air supply duct 32B is connected.

The air conditioner 1 shown in Figures 2 and 3 is a four-way ceiling cassette type air conditioner 1 that has air outlets on all four sides and is embedded in the ceiling, but the air conditioner 1 may be of other types such as a wall-mounted type. Although omitted in Figures 2 and 3, the air conditioning system 100 may include a carbon dioxide sensor 2 installed in each of the multiple areas, or may include a carbon dioxide sensor 2 in some of the multiple areas. When a carbon dioxide sensor 2 is installed in each area, each carbon dioxide sensor 2 acquires the carbon dioxide concentration in each area.

In Figures 2 and 3, an air conditioner 1 installed in each area conditions the area. In Figure 2, four ventilation devices 3 each ventilate one of the four areas. In Figure 3, two ventilation devices 3 each ventilate two areas where two exhaust ports in exhaust duct 32A and two intake ports in intake duct 32B are located.

In the case illustrated in FIG. 2, when a carbon dioxide sensor 2 is installed in each area, the ventilation device 3 ventilating each area ventilates each area based on the concentration acquired by the carbon dioxide sensor 2 installed in each area. In the case illustrated in FIG. 2, when a carbon dioxide sensor 2 is installed in one area out of all areas, the ventilation device 3 ventilating each area ventilates each area based on the concentration acquired by the carbon dioxide sensor 2 in that one area. In the case illustrated in FIG. 2, when a carbon dioxide sensor 2 is installed in two or more areas out of all areas, the ventilation device 3 ventilating the area in which the carbon dioxide sensor 2 is installed ventilates that area based on the concentration acquired by that carbon dioxide sensor 2. On the other hand, the ventilation device 3 ventilating an area in which no carbon dioxide sensor 2 is installed ventilates that area based on, for example, the concentration acquired by the carbon dioxide sensor 2 placed closest to that area.

In the case illustrated in FIG. 3, one or more carbon dioxide sensors 2 are installed in two or more areas to be ventilated by each ventilation device 3. Alternatively, one carbon dioxide sensor 2 is installed in the room. When one or more carbon dioxide sensors 2 are installed in two or more areas to be ventilated by each ventilation device 3, each ventilation device 3 ventilates the two or more areas based on the concentration acquired by the one or more carbon dioxide sensors 2 installed in the two or more areas to be ventilated. For example, when a carbon dioxide sensor 2 is installed in each of two or more areas to be ventilated by each ventilation device 3, each ventilation device 3 may ventilate the two or more areas based on the average concentration acquired by the carbon dioxide sensors 2 installed in each of the two or more areas to be ventilated. When one carbon dioxide sensor 2 is installed in the room, each ventilation device 3 ventilates the two or more areas to be ventilated based on the concentration acquired by the one carbon dioxide sensor 2.

2 and 3, in the first embodiment, air conditioning and ventilation can be realized in each area. However, when the ventilation device 3 and the air conditioner 1 are arranged for each area, the distance between the air conditioner 1 and the ventilation device 3 may not be sufficiently secured in the same area. Also, when the air intake of the duct 32 connected to the ventilation device 3 and the air conditioner 1 are arranged for each area, the distance between the air intake of the duct 32 and the air conditioner 1 may not be sufficiently secured in the same area. In these cases, the air conditioner 1 is more likely to directly suck in the air blown out from the ventilation device 3. That is, the air conditioner 1 is more likely to suck in air at a temperature that is the same as the outside air temperature that flows out from the ventilation device 3. This phenomenon is particularly likely to occur with an increase in the ventilation air volume. Therefore, the air conditioning intake temperature sensor 10 acquires a temperature that does not reflect the air conditioning process. Therefore, even if the temperature in the room is the same as the set temperature or close to the set temperature, the air conditioner 1 can maintain or increase the air conditioning capacity based on the intake temperature acquired by the air conditioning intake temperature sensor 10. As a result, the indoor temperature is lowered or raised beyond the set temperature. That is, in cooling operation, the indoor temperature continues to drop beyond the set temperature, and in heating operation, the indoor temperature continues to rise beyond the set temperature. This reduces the comfort of the user and wastes energy. To prevent such a situation, the air conditioning system 100 according to the first embodiment has the following configuration and functions.

The control device 5 in the first embodiment corrects the suction temperature acquired by the air conditioning suction temperature sensor 10 with the return air temperature acquired by the return air temperature sensor 30. Specifically, the control device 5 corrects the suction temperature according to the following formula (1).
T _AA = T _AB × α + T _V (1-α) ... (1)

In formula (1), T _AA is the corrected intake temperature, T _AB is the uncorrected intake temperature, and T _V is the return air temperature. α is a coefficient determined based on both or one of the ventilation air volume and the outdoor air set temperature difference, and is a number between 0 and 1. The outdoor air set temperature difference is the difference between the outdoor air temperature and the set temperature. Hereinafter, α may be referred to as the first correction coefficient. Hereinafter, a method for determining the first correction coefficient α by the control device 5 will be described with reference to FIG. 4 and FIG. 5.

FIG. 4 is a diagram for explaining a method of determining a first correction coefficient based on the ventilation air volume in the first embodiment. FIG. 5 is a diagram for explaining a method of determining a first correction coefficient based on the outdoor air set temperature difference in the first embodiment. In FIG. 4, the horizontal axis indicates the ventilation air volume, and the vertical axis indicates the air temperature. Note that FIG. 4 and FIG. 5 show a case where the air conditioner 1 performs cooling operation. In FIG. 4, the line L1 _AB indicates the relationship between the suction temperature before correction and the ventilation air volume, and the line L1 _V indicates the relationship between the return air temperature and the ventilation air volume. As shown by the line L1 _AB , the suction temperature acquired by the air conditioning suction temperature sensor 10 increases with an increase in the ventilation air volume. Then, when the ventilation air volume is the limit air volume V _LIM , the suction temperature acquired by the air conditioning suction temperature sensor 10 is equal to the outdoor air temperature T _O. On the other hand, as shown by the line L1 _V , the return air temperature acquired by the return air temperature sensor 30 decreases with an increase in the ventilation air volume. The reason is that the higher the flow rate of the air on the exhaust air duct 3A, the lower the temperature of the air. As shown by the lines _LAB and _L1V , the change in the return air temperature with respect to an increase in the ventilation air volume is slower than the change in the suction temperature with respect to an increase in the ventilation air volume. Therefore, even when the ventilation air volume increases, the return air temperature is closer to the indoor temperature T _I than the suction temperature.

The horizontal axis in Fig. 5 indicates the outdoor air temperature setting difference, and the vertical axis indicates the air temperature. Line L2 _AB in Fig. 5 indicates the relationship between the intake temperature before correction and the outdoor air temperature setting difference when the ventilation air volume is the first comparative air volume _V1 in Fig. 4. Line L3 _AB in Fig. 5 indicates the relationship between the intake temperature before correction and the outdoor air temperature setting difference when the ventilation air volume is the second comparative air volume _V2 in Fig. 4. Note that the second comparative air volume _V2 is larger than the first comparative air volume _V1 . As shown by lines L2 _AB and L3 _AB , the intake temperature acquired by the air conditioning intake temperature sensor 10 becomes higher as the outdoor air temperature setting difference increases. In other words, the intake temperature acquired by the air conditioning intake temperature sensor 10 is more affected by the outdoor air temperature as the outdoor air temperature setting difference increases. Therefore, the error of the intake temperature acquired by the air conditioning intake temperature sensor 10 from the indoor temperature may increase as the outdoor air temperature setting difference increases.

Next, comparing the suction temperatures indicated by lines _L2AB and _L3AB when the outdoor air set temperature difference is the comparative temperature difference ΔT _C , the suction temperature indicated by line _L3AB is higher than the suction temperature indicated by line _L2AB . Therefore, in Fig. 5 as in Fig. 4, the suction temperature acquired by air conditioning suction temperature sensor 10 rises with an increase in the ventilation air volume. And, as shown in Fig. 5, the increase in the suction temperature acquired by air conditioning suction temperature sensor 10 for a fixed increase in the outdoor air set temperature difference is larger the greater the ventilation air volume.

The control device 5 of the first embodiment determines the first correction coefficient α based on both or either one of the ventilation air volume and the outdoor air set temperature difference. More specifically, the control device 5 reduces the first correction coefficient α the greater the ventilation air volume. Also, the control device 5 reduces the first correction coefficient α the greater the outdoor air set temperature difference. In other words, the greater the ventilation air volume, the more the control device 5 corrects the suction temperature acquired by the air conditioning suction temperature sensor 10 to be closer to the return air temperature. Also, the greater the outdoor air set temperature difference, the more the control device 5 corrects the suction temperature acquired by the air conditioning suction temperature sensor 10 to be closer to the return air temperature.

Line L1 _AA in FIG. 4 shows the relationship between the corrected intake temperature and ventilation air volume. In this way, the larger the ventilation air volume, the smaller the first correction coefficient α, and the larger the outdoor air set temperature difference, the larger the correction based on formula (1) in which the first correction coefficient α is made smaller, and the larger the outdoor air set temperature difference, the closer the intake temperature is to the indoor temperature than before the correction. This allows the control device 5 to control the air conditioner 1 based on the intake temperature, which is a more accurate indoor temperature. Therefore, the air conditioner 1 can reduce the air conditioning capacity when the indoor temperature approaches the set temperature and when the indoor temperature reaches the set temperature, thereby reducing wasteful energy consumption. In addition, in the case of cooling operation, the indoor temperature is prevented from continuing to be lower than the set temperature, and in the case of heating operation, the indoor temperature is prevented from continuing to be higher than the set temperature.

The hardware configuration of the control device 5 according to the first embodiment will be described below with reference to FIG. 6. FIG. 6 is a block diagram illustrating an example of the hardware configuration of the control device 5 according to the first embodiment. The control device 5 can be configured, for example, by a processor 51 and a memory 52 connected to each other by a bus 50, and an input/output interface circuit 53. The processor 51 is, for example, a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). The memory 52 is, for example, a ROM (Read Only Memory) or a RAM (Random Access Memory). The input/output interface circuit 53 is a circuit that enables the control device 5 to transmit and receive various signals between other devices via wired or wireless communication.

The control device 5 can achieve the function of acquiring the concentration from one or more carbon dioxide sensors 2 and the function of acquiring the outside air temperature from one or more outside air temperature sensors 4 by the input/output interface circuit 53. The control device 5 can also achieve the function of acquiring the suction temperature from one or more air conditioning suction temperature sensors 10 and the function of acquiring the return air temperature from one or more return air temperature sensors 30 by the input/output interface circuit 53. The control device 5 can also achieve the function of controlling one or more air conditioners 1 and one or more ventilators 3 by the input/output interface circuit 53. The control device 5 can achieve the function of determining the first correction coefficient and the function of correcting the suction temperature acquired from one or more air conditioning suction temperature sensors 10 by the processor 51 reading and executing various programs and data stored in the memory 52.

In addition, when the control device 5 is installed separately in multiple devices among one or more air conditioners 1 and one or more ventilators 3, the control device 5 has multiple processors 51, multiple memories 52, multiple input/output interface circuits 53, and multiple communication interface circuits (not shown). Each of the multiple processors 51, each of the multiple memories 52, each of the multiple input/output interface circuits 53, and each of the multiple communication interface circuits are connected by each of the multiple buses 50. The parts of the control device 5 located in the different devices can communicate with each other via the communication interface circuits.

The functions of the control device 5 may be obtained by cooperation between software and hardware as described above, or may be obtained by dedicated hardware. For example, all or part of the control device 5 may be configured by hardware such as a CPLD (Complex Programmable Logic Device) or an FPGA (Field Programmable Gate Array).

The air conditioning process of the first embodiment will be described below with reference to FIG. 7. FIG. 7 is a flow chart illustrating the flow of the air conditioning process by the air conditioning system 100 according to the first embodiment. Note that the process flow from step S1 to step S6 in FIG. 7 is the process flow for each area when the air conditioning system 100 includes multiple air conditioners 1 and the like and the space to be air conditioned is divided into multiple areas. In this case, the processes from step S1 to step S6 for each area are executed in parallel.

In step S1, the control device 5 acquires the carbon dioxide concentration from the carbon dioxide sensor 2. In step S2, the control device 5 determines whether the concentration acquired in step S1 is equal to or greater than a reference concentration. The reference concentration is predetermined. If the concentration is less than the reference concentration (step S2: NO), the air conditioning system 100 returns the air conditioning process to step S1. If the concentration is equal to or greater than the reference concentration (step S2: YES), in step S3, the ventilation device 3 increases the ventilation air volume based on an instruction from the control device 5. The ventilation device 3 may increase the ventilation air volume by a predetermined amount regardless of the difference in concentration from the reference concentration, or may increase the ventilation air volume by a larger amount the higher the concentration is from the reference concentration.

In step S4, the control device 5 determines the first correction coefficient α based on either or both of the increased ventilation air volume in step S3 and the outdoor air set temperature difference.

In step S5, the control device 5 corrects the suction temperature based on formula (1) using the first correction coefficient α determined in step S4. That is, the control device 5 substitutes the value of the first correction coefficient α determined in step S4, the suction temperature acquired by the air conditioning suction temperature sensor 10, and the return air temperature acquired by the return air temperature sensor 30 into formula (1) to obtain the corrected suction temperature. Note that after the processing of step S1 and before the processing of step S5, the control device 5 acquires the suction temperature from the air conditioning suction temperature sensor 10 and the return air temperature from the return air temperature sensor 30.

In step S6, the control device 5 controls the air conditioner 1 based on the corrected intake temperature. After processing in step S6, the air conditioning system 100 returns the air conditioning process to step S1.

In the air conditioning process shown in FIG. 7, in step S2, the control device 5 determines whether the carbon dioxide concentration is equal to or higher than a reference concentration, and if the concentration is equal to or higher than the reference concentration, the ventilation device 3 increases the ventilation air volume in step S3. However, instead of the processes in steps S2 and S3, the air conditioning system 100 may perform the following process. That is, the control device 5 may determine the ventilation air volume according to the concentration obtained in step S1, and the ventilation device 3 may perform ventilation at the ventilation air volume determined by the control device 5.

Embodiment 2.
Hereinafter, an air conditioning system 100 according to the second embodiment will be described. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals. In the second embodiment, the same configurations as those in the first embodiment and the same functions as those in the first embodiment will not be described unless there are special circumstances.

The configuration of the air conditioning system 100 according to the second embodiment is illustrated in FIG. 1, as in the first embodiment. The hardware configuration of the air conditioning system 100 according to the second embodiment is illustrated in FIG. 6, as in the first embodiment. Here, the air conditioning system 100 according to the second embodiment includes multiple air conditioners 1. An example of the installation of the multiple air conditioners 1 and one or more ventilators 3 in the second embodiment is shown in FIG. 2 and FIG. 3.

For ease of understanding, the following will describe a case where the control device 5 controls air conditioning by any one of the multiple air conditioners 1. Note that, hereinafter, the suction temperature that is the subject of correction by the control device 5 may be referred to as the first suction temperature, and the air conditioning suction temperature sensor 10 that acquires the first suction temperature may be referred to as the first suction temperature sensor. An air conditioner 1 that is provided with a first suction temperature sensor and performs air conditioning based on the first suction temperature corrected by the control device 5 may be referred to as the first air conditioner. The area that is the subject of air conditioning by the first air conditioner may be referred to as the first area. Furthermore, the ventilation device 3 that ventilates the first area may be referred to as the first ventilation device, and the ventilation air volume by the first ventilation device may be referred to as the first ventilation air volume.

The control device 5 in the second embodiment corrects the first intake temperature acquired by the first intake temperature sensor based on the return air temperature and the second intake temperature. The return air temperature is a temperature acquired by the return air temperature sensor 30 provided in the first ventilation device. The second intake temperature is a temperature acquired by the air conditioning intake temperature sensor 10 in the air conditioner 1 installed in an area adjacent to the first area. In the following, the area adjacent to the first area may be referred to as the second area. The air conditioner 1 installed in the second area may be referred to as the second air conditioner. The ventilation device 3 that ventilates the second area may be referred to as the second ventilation device, and the ventilation air volume by the second ventilation device may be referred to as the second ventilation air volume. Furthermore, the air conditioning intake temperature sensor 10 provided in the second air conditioner may be referred to as the second intake temperature sensor.

The control device 5 in the second embodiment corrects the first suction temperature based on the following equation (2).
T _AA = T _AB × α + T _V × β + Σ ( T _i × γ _i ) ... (2)

In formula (2), T _AA , T _AB , and T _V are the corrected first suction temperature, the uncorrected first suction temperature, and the return air temperature, respectively, as in formula (1). _{T i} is the second suction temperature acquired by the second suction temperature sensor. i is a virtual number assigned to the second region for ease of understanding. i is a natural number from 1 to n. n is the total number of second regions, and is a number from 2 to 4. When the air-conditioned space includes four regions as in Figures 2 and 3, n is 2.

In formula (2), Σ(T _i ×γ _i ) is the sum of each of (T _i ×γ _i ) where i ranges from 1 to n. In formula (2), α is a first correction coefficient, the value of which changes depending on both or either of the first ventilation airflow rate and the first outdoor air set temperature difference. Here, the first outdoor air set temperature difference is the outdoor air set temperature difference in the first region, and is the difference between the set temperature, which is the temperature set in the first air conditioner, and the outdoor air temperature. In formula (2), β is a coefficient whose value changes depending on both or either of the first ventilation airflow rate and the first outdoor air set temperature difference. Hereinafter, β may also be referred to as a second correction coefficient.

In formula (2), γ _i is determined based on the distance between the second air conditioner installed in the i-th second region and the first region. Hereinafter, the distance between the second air conditioner and the first region may be referred to as the adjacent distance. Hereinafter, γ _i may be referred to as the third correction coefficient. The third correction coefficient γ _i may be determined based on the second ventilation airflow rate by the second ventilation device that ventilates the i-th second region, instead of or together with the adjacent distance.

The sum of the third correction coefficients γ _i from 1 to n, the sum of the first correction coefficient α, and the second correction coefficient β is equal to 1. The first correction coefficient α becomes smaller as the first ventilation airflow rate is larger, and the first outdoor air set temperature difference becomes larger. The second correction coefficient β becomes larger as the first ventilation airflow rate is larger, and the first outdoor air set temperature difference becomes larger. The third correction coefficient γ _i becomes larger as the adjacent distance between the first air conditioner in the i-th second region and the first region is shorter within a range equal to or greater than a predetermined lower limit distance. On the other hand, when the adjacent distance between the first air conditioner in the i-th second region and the first region is less than the lower limit distance, the third correction coefficient γ _i becomes smaller as the adjacent distance becomes shorter. That is, when the adjacent distance between the second air conditioner in the i-th region and the first region is equal to or greater than the lower limit distance, the control device 5 brings the first suction temperature closer to the second suction temperature measured by the second suction temperature sensor in the i-th region as the adjacent distance becomes shorter. On the other hand, when the adjacent distance is less than the lower limit distance, the control device 5 brings the first suction temperature closer to the second suction temperature measured by the second suction temperature sensor in the i-th region as the adjacent distance becomes longer. The third correction coefficient γ _i may be smaller as the second ventilation airflow rate in the i-th second region becomes larger. The third correction coefficient γ _i may be 0 when the second ventilation airflow rate in the i-th second region exceeds a predetermined threshold adjacent airflow rate.

Specifically, the first correction coefficient α, the second correction coefficient β, and the third correction coefficient γ _i are determined as follows. The sum of the first correction coefficient α and the second correction coefficient β is determined in advance as, for example, 0.6 or 0.7. At this time, the sum of the third correction coefficients γ _i for i from 1 to n is the difference from 1 of the sum of the first correction coefficient α and the second correction coefficient β, and is determined to be 0.3 if the sum of the first correction coefficient α and the second correction coefficient β is determined to be 0.7. Hereinafter, the predetermined sum of the first correction coefficient α and the second correction coefficient β may be referred to as the first sum. Hereinafter, the predetermined sum of the third correction coefficients γ _i may be referred to as the second sum. The control device 5 reduces the first correction coefficient α and increases the second correction coefficient β as the first ventilation airflow rate increases, so that the sum of the first correction coefficient α and the second correction coefficient β becomes the first sum. The control device 5 decreases the first correction coefficient α and increases the second correction coefficient β as the first outdoor air set temperature difference increases, so that the sum of the first correction coefficient α and the second correction coefficient β becomes the first sum. When the adjacent distance between the second air conditioner and the first region in the i-th second region is equal to or greater than the lower limit distance, the control device 5 increases the third correction coefficient γ _i as the adjacent distance becomes smaller, and when the adjacent distance is less than the lower limit distance, the control device 5 decreases the third correction coefficient γ _i as the adjacent distance becomes smaller. The control device 5 may decrease the third correction coefficient γ _i as the second ventilation air volume in the i-th second region increases. The control device 5 determines each third correction coefficient γ _i such that the sum of the respective third correction coefficients γ _i from 1 to n becomes the second sum.

The first sum and the second sum may be determined according to the number of second regions or the total sum of the second ventilation airflows in all second regions, or may be constants. For example, the greater the number of second regions, the smaller the first sum is set and the larger the second sum is set. Also, the greater the total sum of the second ventilation airflows in all second regions, the larger the first sum is set and the smaller the second sum is set.

FIG. 8 is a flow chart illustrating the flow of air conditioning processing by the air conditioning system 100 according to the second embodiment. In step S11, the control device 5 acquires the carbon dioxide concentration from the carbon dioxide sensor 2. If the carbon dioxide sensor 2 is installed in the first region, the control device 5 acquires the carbon dioxide concentration from the carbon dioxide sensor 2 installed in the first region in step S11. On the other hand, if the carbon dioxide sensor 2 is not installed in the first region and two or more carbon dioxide sensors 2 are installed in one or more other regions, the control device 5 acquires the carbon dioxide concentration from the carbon dioxide sensor 2 closest to the first region in step S11. If one carbon dioxide sensor 2 is installed in the space to be air conditioned, the control device 5 acquires the carbon dioxide concentration from that one carbon dioxide sensor 2 in step S11. The processing in step S12 is the same as the processing in step S2 in the first embodiment.

In step S13, the first ventilation device increases the first ventilation air volume based on an instruction from the control device 5. In step S14, the control device 5 determines a first correction coefficient α, a second correction coefficient β, and a third correction coefficient γ _i . In step S15, the control device 5 corrects the first suction temperature based on formula (2) using the first correction coefficient α, the second correction coefficient β, and the third correction coefficient γ _i determined in step S14. That is, the control device 5 substitutes each value of the first correction coefficient α, the second correction coefficient β, and the third correction coefficient γ _i determined in step S14, the first suction temperature acquired by the first suction temperature sensor, the return air temperature acquired by the return air temperature sensor 30 in the first ventilation device, and the second suction temperature acquired by the second suction temperature sensor into formula (2) to obtain the corrected first suction temperature. In addition, after processing of step S11 and before processing of step S15, the control device 5 acquires the first suction temperature from the first suction temperature sensor, acquires the second suction temperature from the second suction temperature sensor, and acquires the return air temperature from the return air temperature sensor 30 in the first ventilation device.

In step S16, the control device 5 controls the first air conditioner based on the corrected first suction temperature. After processing in step S16, the air conditioning system 100 returns the air conditioning process to step S11.

Instead of the processes of steps S12 and S13, the air conditioning system 100 may perform the following process. That is, the control device 5 may determine a first ventilation air volume according to the concentration obtained in step S11, and the first ventilation device may perform ventilation at the first ventilation air volume determined by the control device 5.

The effects of the air conditioning system 100 according to the first and second embodiments are described below. The air conditioning system 100 according to the first and second embodiments includes a first air conditioner, a first ventilation device, a first intake temperature sensor, a return air temperature sensor 30, and a control device 5. The first air conditioner conditions a first region in the space to be air-conditioned. The first ventilation device ventilates the first region. The first intake temperature sensor acquires a first intake temperature, which is the temperature of the air sucked in by the air conditioner 1 from the space to be air-conditioned. The return air temperature sensor 30 acquires a return air temperature, which is the temperature of the air sucked in by the first ventilation device from the first region. The control device 5 controls the first ventilation device and the first air conditioner. The control device 5 corrects the first intake temperature based on the return air temperature. The control device 5 then controls the first air conditioner to perform air conditioning based on the corrected first intake temperature.

With the above configuration, the control device 5 corrects the first intake temperature acquired by the first intake temperature sensor based on the return air temperature. As a result, even if air blown out from the first ventilation device at a temperature equivalent to the outside air temperature flows into the air conditioner 1, the first air conditioner can perform further air conditioning processing based on the more accurate first intake temperature as the temperature of the first area reflecting the air conditioning processing. Therefore, in the case of cooling operation, the temperature of the first area does not drop too much below the set temperature of the first air conditioner, and in the case of heating operation, the temperature of the first area does not rise too much above the set temperature, reducing unnecessary energy consumption and ensuring user comfort.

In the first and second embodiments, the control device 5 corrects the first suction temperature acquired by the first suction temperature sensor so that the temperature is closer to the return air temperature as the first ventilation airflow rate by the first ventilation device increases. The larger the first ventilation airflow rate, the more likely it is that the first air conditioner will suck in air blown out from the first ventilation device at a temperature the same as the outside air temperature. Therefore, the first suction temperature acquired by the first suction temperature sensor may have low accuracy as the temperature of the first area. On the other hand, the return air temperature acquired by the return air temperature sensor 30 is often more accurate as the temperature of the first area than the first suction temperature acquired by the first suction temperature sensor. Therefore, the larger the first ventilation airflow rate, the more the first suction temperature is corrected to be closer to the return air temperature, thereby improving the accuracy of control of the first air conditioner.

The air conditioning system 100 in the first and second embodiments further includes an outdoor air temperature sensor 4. The outdoor air temperature sensor 4 acquires the outdoor air temperature. The control device 5 corrects the first suction temperature acquired by the first suction temperature sensor so that the corrected first suction temperature approaches the return air temperature as the first outdoor air set temperature difference, which is the difference between the set temperature of the first air conditioner and the outdoor air temperature, becomes larger. The larger the first outdoor air set temperature difference, the lower the accuracy of the first suction temperature acquired by the first suction temperature sensor as the temperature of the first region. On the other hand, the return air temperature acquired by the return air temperature sensor 30 often has a higher accuracy as the temperature of the first region than the first suction temperature acquired by the first suction temperature sensor. Therefore, the larger the first outdoor air set temperature difference, the more the first suction temperature is corrected to approach the return air temperature, thereby improving the accuracy of control of the first air conditioner.

The air conditioning system 100 according to the first and second embodiments further includes a carbon dioxide sensor 2. The carbon dioxide sensor 2 acquires the concentration of carbon dioxide in the space to be air-conditioned. The control device 5 determines the first ventilation airflow rate based on the concentration acquired by the carbon dioxide sensor 2. This allows ventilation to be performed according to the concentration of carbon dioxide in the space to be air-conditioned. Therefore, when the concentration of carbon dioxide in the space to be air-conditioned is high, ventilation is performed quickly, and when the concentration of carbon dioxide in the space to be air-conditioned is low, energy conservation is achieved.

The air conditioning system 100 according to the second embodiment further includes a second air conditioner and a second intake temperature sensor. The second air conditioner conditions a second area adjacent to the first area. The second intake temperature sensor acquires a second intake temperature, which is the temperature of the air that the second air conditioner draws in from the second area. The control device 5 corrects the first intake temperature based on the return air temperature and the second intake temperature, and controls the first air conditioner to perform air conditioning based on the corrected first intake temperature.

With the above configuration, the control device 5 corrects the first suction temperature based on not only the return air temperature but also the second suction temperature, which provides the following effects. First, there are cases where the first ventilation device sucks in air that the first ventilation device has blown into the room. In such cases, the return air temperature becomes close to the outside air temperature, and there is a possibility that an error occurs with the temperature of the first area. However, because the control device 5 corrects the first suction temperature based on the second suction temperature as well as the return air temperature, the error of the corrected first suction temperature from the temperature of the first area can be reduced. Therefore, the first air conditioner can perform air conditioning with high accuracy based on the corrected first suction temperature.

In embodiment 2, when the adjacent distance, which is the distance between the second air conditioner and the first area, is equal to or greater than a predetermined lower limit distance, the control device 5 corrects the first suction temperature acquired by the first suction temperature sensor so that the shorter the adjacent distance, the closer the temperature to the second suction temperature. When the adjacent distance is less than the lower limit distance, the control device 5 corrects the first suction temperature acquired by the first suction temperature sensor so that the longer the adjacent distance, the closer the temperature to the second suction temperature. The shorter the adjacent distance, the closer the second suction temperature is to the temperature of the first area. On the other hand, the shorter the distance between the second air conditioner and the first ventilation device, the greater the difference between the second suction temperature and the temperature of the first area will be because the second air conditioner sucks in air blown out from the first ventilation device. When the adjacent distance is equal to or greater than the lower limit distance, i.e., when the second air conditioner is sufficiently far from the first ventilation device, the shorter the adjacent distance, the closer the control device 5 brings the first suction temperature to the second suction temperature, and the more accurate the first suction temperature can be as the temperature of the first region. On the other hand, when the adjacent distance is less than the lower limit distance, i.e., when the second air conditioner is closer to the first ventilation device, the longer the adjacent distance, the closer the control device 5 brings the first suction temperature to the second suction temperature, and the more accurate the first suction temperature can be as the temperature of the first region. Thus, the accuracy of control of the first air conditioner is improved.

The air conditioning system 100 according to the second embodiment further includes a second ventilation device that ventilates the second area. The control device 5 corrects the first intake temperature acquired by the first intake temperature sensor so that the smaller the second ventilation airflow rate by the second ventilation device, the closer the temperature to the second intake temperature. When the second ventilation airflow rate is large, the second air conditioner is more likely to draw in air at a temperature equivalent to the outdoor air temperature blown out from the second ventilation device. As a result, the temperature acquired by the second intake temperature sensor is more likely to be closer to the outdoor air temperature than the room temperature. On the other hand, when the second ventilation airflow rate is small, the second air conditioner is less likely to draw in air from the second ventilation device, and the second intake temperature approaches the room temperature. Therefore, the control device 5 corrects the first intake temperature so that the smaller the second ventilation airflow rate, the closer the temperature to the second intake temperature, and the air conditioning system 100 can suppress a decrease in the accuracy of the air conditioning process.

In the second embodiment, an example was shown in which the control device 5 corrects the first suction temperature based on the second suction temperature together with the return air temperature. However, the control device 5 may perform a correction based on the return air temperature when the first ventilation air volume is small, and may perform a correction based on the return air temperature and the second suction temperature when the first ventilation air volume is large. In detail, the control device 5 corrects the first suction temperature based on the return air temperature based on formula (1) as in the first embodiment when the first ventilation air volume is less than a predetermined threshold air volume. Then, when the first ventilation air volume is equal to or greater than the threshold air volume, the control device 5 corrects the first suction temperature based on the return air temperature and the second suction temperature based on formula (2). When the first ventilation air volume is small, the first ventilation device is less likely to suck in the air that has been blown out. Therefore, when the first ventilation air volume is less than the threshold air volume, the control device 5 corrects the first suction temperature based on the return air temperature, and the air conditioning system 100 can reduce the amount of correction processing while maintaining or improving the accuracy of control of the first air conditioner. On the other hand, when the first ventilation airflow rate is large, the first ventilation device is more likely to suck in the air that is blown out. Therefore, when the first ventilation airflow rate is equal to or greater than the threshold airflow rate, the control device 5 corrects the first suction temperature based on the second suction temperature together with the return air temperature, so that the air conditioning system 100 can maintain or improve the accuracy of control of the first air conditioner.

Although the embodiments have been described above, the contents of this disclosure are not limited to the embodiments and include the scope of conceivable equivalents. Furthermore, the configurations and variations thereof described in the first and second embodiments can be combined with each other to the extent that the functions and operations are not impaired.

1 air conditioner, 2 carbon dioxide sensor, 3 ventilation device, 3A exhaust air duct, 3B supply air duct, 4 outside air temperature sensor, 5 control device, 10 air conditioner intake temperature sensor, 30 return air temperature sensor, 31 total heat exchanger, 32 duct, 32A exhaust duct, 32B supply air duct, 50 bus, 51 processor, 52 memory, 53 input/output interface circuit, 100 air conditioning system.

Claims

A first air conditioner that conditions a first area in a space to be air conditioned;
A first ventilation device that ventilates the first area;
a first intake temperature sensor that acquires a first intake temperature, which is the temperature of air that the first air conditioner draws in from the first area;
A return air temperature sensor that acquires a return air temperature, which is the temperature of air sucked in from the first area by the first ventilation device;
A control device that controls the first ventilation device and the first air conditioner;
Equipped with
The control device includes:
An air conditioning system that corrects the first suction temperature based on the return air temperature, and controls the first air conditioner to perform air conditioning based on the corrected first suction temperature.
The control device includes:
The air conditioning system according to claim 1 , wherein the first suction temperature acquired by the first suction temperature sensor is corrected so that the first suction temperature is closer to the return air temperature as the ventilation air volume by the first ventilation device is larger.
Further comprising an outside air temperature sensor for acquiring an outside air temperature which is the temperature of air outside the air conditioned space,
The control device includes:
The air conditioning system of claim 1 or claim 2, wherein the first suction temperature acquired by the first suction temperature sensor is corrected so that the corrected first suction temperature approaches the return air temperature the larger the first outdoor air set temperature difference, which is the difference between the set temperature set in the first air conditioner and the outdoor air temperature.
A second air conditioner that conditions a second area adjacent to the first area in the air conditioned space;
a second suction temperature sensor that acquires a second suction temperature, which is the temperature of air sucked in from the second area by the second air conditioner;
Further comprising:
The control device includes:
An air conditioning system as described in any one of claims 1 to 3, wherein the first suction temperature is corrected based on the return air temperature and the second suction temperature, and the first air conditioner is controlled to perform air conditioning based on the corrected first suction temperature.
The control device includes:
When an adjacent distance between the second air conditioner and the first area is equal to or greater than a predetermined lower limit distance, the first suction temperature acquired by the first suction temperature sensor is corrected so that the shorter the adjacent distance is, the closer the first suction temperature becomes to the second suction temperature;
The air conditioning system of claim 4, wherein when the adjacent distance is less than the lower limit distance, the first suction temperature acquired by the first suction temperature sensor is corrected so that the longer the adjacent distance is, the closer the temperature is to the second suction temperature.
Further comprising a second ventilation device for ventilating the second area,
The control device includes:
The air conditioning system according to claim 4 or claim 5, wherein the first suction temperature acquired by the first suction temperature sensor is corrected so that the smaller the ventilation air volume by the second ventilation device is, the closer the temperature is to the second suction temperature.
Further comprising a carbon dioxide sensor for acquiring a concentration of carbon dioxide in the air-conditioned space,
The control device includes:
The air conditioning system according to any one of claims 1 to 6, further comprising: determining a ventilation air volume to be provided by the first ventilation device based on the concentration.