Ventilation system and air conditioner

Abstract

To provide a ventilation system, an air conditioner and a control method capable of measuring air quality to be actually supplied to an indoor side and appropriately performing control of air supply / discharge.SOLUTION: A ventilation system includes: an air supply air course 18 having an air supply fan 21 for supplying outdoor air to an indoor side; an air discharge air course 19 having an air discharge fan 23 for discharging indoor air to an outdoor side; a heat exchanger 11 disposed in the middle of the air supply air course 18 and the air discharge air course 19 and at least exchanging heat between the indoor air and the outdoor air; an IAQ sensor 31 installed at a position adjacent to the indoor side and measuring air quality of the outdoor air that has passed through the heat exchanger 11 and is to be supplied to the indoor side by the air supply fan 21; and a control circuit 30 controlling air supply / discharge by using the air supply fan 21 and the air discharge fan 23 on the basis of a measurement result obtained by the IAQ sensor 31.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a ventilation system, an air conditioner, and a control method for controlling supply and exhaust air.

Background Art

[0002] Buildings such as houses, buildings, and hospitals have improved airtightness for energy conservation and comfort. When the airtightness of a building improves, water vapor, carbon dioxide, various odor components, etc. generated indoors accumulate as pollutants, and the indoor air quality (IAQ: Indoor Air Quality) tends to deteriorate. For this reason, there is an increasing need for a ventilation system to discharge these pollutants to the outside, take in fresh air from the outside, and maintain good air quality.

[0003] Ventilation systems include a system that only performs supply and exhaust air between indoors and outdoors, a system equipped with a sensible heat exchange element capable of transferring heat in supply and exhaust air, and a system equipped with a total heat exchange element capable of transferring heat and humidity in supply and exhaust air.

[0004] As a system equipped with a total heat exchange element, a system is known that controls the air volume and ventilation mode according to the air quality of the outside air (OA: Outdoor Air) to be introduced and the air quality of the air in the exhaust air (RA: Return Air) (see, for example, Patent Document 1). In this system, a CO2 sensor is installed in the exhaust passage to detect the CO2 concentration of the air in the exhaust air, and based on the detected CO2 concentration, the air volume control of the supply and exhaust air is performed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the above conventional technology, since a CO2 sensor is installed in the exhaust passage, the air quality of the outside air cannot be measured. Then, even when the CO2 concentration, PM2.5, etc. of the outside air increase, the air volume cannot be decreased or the fan cannot be stopped.

[0007] By installing a sensor in the outside air introduction section, the air quality of the outside air can be measured. However, in a system equipped with a total heat exchanger, there is a problem that the accuracy of supply and exhaust control is low because the measured air quality does not represent the air quality supplied to the room.

Means for Solving the Problems

[0008] In view of the above problems, the present invention is a ventilation system that controls supply and exhaust air, a supply air duct provided with supply air means for supplying outside air into the room, an exhaust air duct provided with exhaust air means for discharging indoor air to the outside, a heat exchanger disposed in the middle of the supply air duct and the exhaust air duct, which performs at least heat exchange between indoor air and outdoor air, measuring means installed at a position adjacent to the room, for measuring the air quality of the outside air after passing through the heat exchanger supplied into the room by the supply air means, control means for controlling the supply and exhaust air by the supply air means and the exhaust air means based on the measurement result of the measuring means A ventilation system is provided that includes

Effects of the Invention

[0009] According to the present invention, it is possible to measure the air quality actually supplied to the room, and it is possible to improve the accuracy of supply and exhaust control.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0011] Figure 1 is a diagram showing a configuration example of the ventilation system according to the present embodiment. The ventilation system is a system for exchanging indoor air and outdoor air in order to ensure the air quality of the air in the building. The air quality indicates the component amount of the target substance in the indoor air, and the target substances are carbon dioxide, carbon monoxide, dust such as PM2.5 and PM10, volatile organic compounds, and the like.

[0012] As shown in Fig. 1(a), the ventilation system includes a substantially rectangular parallelepiped box body 10 and a heat exchanger 11 disposed within the box body 10. At one end of the box body 10 in the longitudinal direction, an air supply inlet 12 for introducing outdoor air (OA) and an exhaust outlet 13 for exhausting indoor air as EA (Exhaust Air) to the outside are provided. At the other end of the box body 10 in the longitudinal direction, an air supply outlet 14 for supplying the air introduced from the air supply inlet 12 to the indoor as SA (Supply Air) and an exhaust inlet 15 for taking in indoor air as RA are provided. Partition plates 16 and 17 are provided within the box body 10 to form an air supply air passage 18 that communicates the outdoor air through the heat exchanger 11 disposed at a substantially central position within the box body 10 between the air supply inlet 12 and the air supply outlet 14, and to form an exhaust air passage 19 that communicates the indoor air through the heat exchanger 11 between the exhaust outlet 13 and the exhaust inlet 15. The air supply air passage 18 and the exhaust air passage 19 are formed to intersect at the heat exchanger 11.

[0013] Within the box body 10, in addition to the air supply air passage 18 and the exhaust air passage 19, a bypass air passage 20 is formed that bypasses the heat exchanger 11 and communicates the exhaust outlet 13 and the exhaust inlet 15. The bypass air passage 20 in Fig. 1 is on the outdoor side of the heat exchanger 11 and communicates with the suction side of an exhaust fan 23 installed within the exhaust air passage 19. The exhaust fan 23 may be installed between the heat exchanger 11 and the exhaust inlet 15, but the bypass air passage 20 still takes a path that bypasses the heat exchanger 11. The bypass air passage 20 is provided with a damper 22 as an opening and closing means that opens and closes on the exhaust inlet 15 side in Fig. 1. By closing the damper 22, the indoor air can flow through the heat exchanger 11, and by opening the damper 22, the indoor air can flow bypassing the heat exchanger 11. Note that the damper 22 and the bypass air passage 20 may be installed at a position that communicates the air supply outlet 14 and the air supply inlet 12.

[0014] The air supply fan 21 is installed between the heat exchanger 11 and the air supply outlet 14 within the air supply air passage 18 in Fig. 1 as an air supply means for introducing outdoor air (OA) into the indoor. Note that the air supply fan 21 may be installed between the heat exchanger 11 and the air supply inlet 12.

[0015] An exhaust fan 23 as an exhaust means for exhausting the indoor air (RA) to the outside is installed in the exhaust air passage 19. The exhaust fan 23 shown in FIG. 1 is installed between the heat exchanger 11 and the exhaust outlet 13 in the exhaust air passage 19, but is not limited thereto, and may be installed between the heat exchanger 11 and the exhaust inlet 15.

[0016] The heat exchanger 11 may be a sensible heat exchanger that exchanges only the heat of the air flowing through the supply air passage 18 and the air flowing through the exhaust air passage 19, or may be a total heat exchanger that exchanges not only heat but also moisture (humidity). Hereinafter, the heat exchanger 11 will be described as a total heat exchanger.

[0017] The total heat exchanger is composed of a total heat exchange element 11a and an element filter 11b. The total heat exchange element 11a is an element with a rectangular shape on each surface. Of the four side surfaces, the element filters 11b are attached to two side surfaces. Of the four corners formed by two adjacent side surfaces of the element with respect to the longitudinal direction of the box body 10, one is adjacent to the box body 10, another is adjacent to the bypass air passage 20, and the other two are adjacent to one end of each of the partition plates 16 and 17.

[0018] The total heat exchange element 11a is made of paper, non-woven fabric, resin, etc. As shown in FIG. 1(b), it has a plurality of layers, and the supply air passage 24 that constitutes a part of the supply air passage 18 and the exhaust air passage 25 that constitutes a part of the exhaust air passage 19 are overlapped alternately with an angle change of about 90°. Therefore, in the total heat exchange element 11a, if the first layer is the supply air passage 24 going from the 0° direction to the 180° direction from above, the second layer is the exhaust air passage 25 going from the 90° direction to the 270° direction, and the third layer is the supply air passage 24 going from the 0° direction to the 180° direction again. Thus, passages through which supply air and exhaust air flow are alternately formed.

[0019] Thereby, while enabling the permeation of heat and moisture through paper or the like, the air does not permeate through paper or the like, so that the supply air and the exhaust air do not mix.

[0020] However, in the total heat exchanger, since a differential pressure is generated during operation and gaps are generated during assembly, a part of the exhaust leaks to the supply air side. Therefore, when there are occupants in the room, the CO2 concentration of the air (SA) actually supplied to the room is higher than the CO2 concentration of the outside air (OA).

[0021] In the supply air duct 18, actuators such as a natural evaporation type humidifier 26, an electric heater 27, and a direct expansion type heat exchanger 28 are installed. These actuators are just examples, and they may not be installed, or one or two of them may be installed, or other devices may be installed. Also, these devices and one or more other devices may be installed.

[0022] The natural evaporation type humidifier 26 includes a vaporization section such as a filter or pottery and a water storage section. The water storage section stores water, and the vaporization section sucks up water from the water storage section by capillary action and humidifies by naturally vaporizing it. Here, a natural evaporation type humidifier is exemplified, but it is not limited to this. A steam type that includes an electric heater and heats water with the electric heater to generate steam for humidification, an ultrasonic type that gives vibration to water by an ultrasonic generator and sprays it in a mist form for humidification, or a hybrid type that includes an electric heater and an ultrasonic generator may also be used.

[0023] The direct expansion type heat exchanger 28 is a heat exchanger that directly exchanges heat with the air used in the air conditioner, and includes a heat transfer tube (coil) through which a refrigerant that exchanges heat with the air flows.

[0024] A filter 29 as a collecting means may be installed in the air supply passage 18. The filter 29 captures fine particles such as PM2.5, pollen, and yellow sand contained in the outside air. As the filter 29, a medium-high performance filter that mainly captures particles of 25 μm or more, or a HEPA filter (High Efficiency Particulate Air filter) that mainly captures particles of 0.3 μm or more can be used. Further, as the filter 29, in addition to these filters, a pre-filter that mainly captures particles of 50 μm or more may be installed.

[0025] The ventilation system shown in FIG. 1 includes a control circuit 30 as a control means, and is electrically connected to the air supply fan 21, the damper 22, the exhaust fan 23, and an IAQ sensor described later, as shown by the broken line. The control circuit 30 can control the air volume of supply and exhaust, switch between the total heat exchange mode and the normal ventilation mode, etc. by transmitting and receiving electrical signals to and from these devices. The total heat exchange mode is a ventilation mode in which the damper 22 is closed and exhaust is performed through the heat exchanger 11, and the normal ventilation mode is a ventilation mode in which the damper 22 is opened, bypasses the heat exchanger 11, and exhausts through the bypass air passage 20.

[0026] The control circuit 30 has the same configuration as the control circuit mounted on the outdoor unit of the air conditioner, and includes a CPU 40, a flash memory 41, a RAM (Random Access Memory) 42, a communication I / F 43, and a control I / F 44, as shown in FIG. 2. Components such as the CPU 40 are connected to the bus 45 and exchange information via the bus 45.

[0027] The CPU 40 controls the entire ventilation system. The flash memory 41 stores programs and various data used for control by the CPU 40. The RAM 42 provides a working area for the CPU 40. The communication I / F 43 receives air quality information from the IAQ sensor. The control I / F 44 is connected to the air supply fan 21, the damper 22, and the exhaust fan 23, and controls each unit.

[0028] Here, the control circuit 30 realizes air volume control and switching of the ventilation mode by the CPU 40 reading a program from the flash memory 41 and executing the program. However, it is not limited to this, and dedicated hardware such as a circuit may be used to realize the above air volume control and the like.

[0029] In order to perform air volume control of supply and exhaust air and switching of the ventilation mode, information serving as a reference for control and switching is necessary, and air quality is used as the information.

[0030] Conventionally, ventilation is performed by measuring the CO2 concentration as the air quality of indoor air with a CO2 sensor which is one of the IAQ sensors, and controlling the air volume and the like so that the concentration does not exceed the target concentration. For this reason, the CO2 sensor is installed between the exhaust inlet 15 in the exhaust air passage 19 and the heat exchanger 11 or indoors.

[0031] When an IAQ sensor for measuring air quality such as a CO2 sensor is installed between the exhaust inlet 15 in the exhaust air passage 19 and the heat exchanger 11, the measured air quality is the air quality of the air after passing through the room, so the air quality of the outside air (OA) cannot be measured. Then, even when the CO2 concentration or PM2.5 of the outside air increases, the air volume cannot be decreased or the fan cannot be stopped.

[0032] If an IAQ sensor is installed near the outside or the air supply inlet 12 of the air supply passage 18, the air quality of the outside air (OA) can be measured. However, the air quality of the outside air (OA) does not represent the actual air quality supplied to the room. This is because the air quality supplied to the room may be improved or deteriorated with respect to the air quality of the outside air (OA) due to the influence of leakage in the filter 29 and the heat exchanger 11.

[0033] Then, even when the air quality of the air (SA) supplied into the room by the filter 29 is improved and the air quality in the room can be sufficiently improved even if the air volume is maintained or decreased, control is performed based on the air quality of the outside air (OA), so control may be performed to increase the air volume. Also, when the air quality of the outside air (OA) significantly deteriorates, even though the air quality of the air (SA) supplied into the room by the filter 29 is maintained, control may be performed to reduce the air volume. In this way, it cannot be said that control is being performed with an appropriate air volume or the like.

[0034] Also, when the IAQ sensor is installed between the exhaust inlet 15 in the exhaust air duct 19 and the heat exchanger 11 for control, outside air is used for calibration, but due to the installation position, it is difficult to bring the IAQ sensor into contact with the outside air. Therefore, various controls such as operating the supply fan 21 and the exhaust fan 23 at maximum air volume and generating an air flow from the supply air outlet 14 through the room toward the exhaust inlet 15 are required.

[0035] Therefore, in this system, the IAQ sensor 31 is installed not between the exhaust inlet 15 in the exhaust air duct 19 and the heat exchanger 11, but between the heat exchanger 11 and the supply air outlet 14 in the supply air duct 18, and on the indoor side of the supply fan 21, the natural evaporation type humidifier 26, the electric heater 27, and the direct expansion type heat exchanger 28 installed therebetween. That is, the IAQ sensor 31 is installed at a position close to the room.

[0036] Thereby, it is possible to measure the CO2 concentration of the air (SA) actually supplied into the room after the outside air (OA) has passed through the heat exchanger 11 and each actuator. Also, it is possible to calibrate the IAQ sensor 31 by opening the damper 22 and flowing the outside air (OA) through the bypass air duct 20.

[0037] Filter 29 is installed between the heat exchanger 11 and the air supply inlet 12 in order to capture fine particles such as PM2.5, pollen, and yellow sand contained in the outside air (OA). Further, the element filter 11b of the heat exchanger 11 is provided on the air supply inlet 12 side. Thereby, the IAQ sensor 31 can measure the particle concentration in the air actually supplied to the room after capturing fine particles with the filter 29 and the element filter 11b.

[0038] In this way, by measuring the air quality of the air actually supplied to the room, it becomes possible to appropriately control the supply and exhaust air and operate with an appropriate air volume and ventilation mode.

[0039] In order to perform appropriate control, it is important how much particles in the air are collected by the filter 29 and how much leakage occurs in the heat exchanger 11. As an index indicating how much is collected, the filter collection efficiency can be used, and as an index indicating how much leakage occurs, the effective ventilation rate can be used.

[0040] With reference to FIG. 3, the relationship between the filter collection efficiency, the effective ventilation rate, and the control will be described. In the ventilation system, as shown in FIG. 3, the filter 29 is installed in the air supply duct 18, and the heat exchanger 11 is installed across the air supply duct 18 and the exhaust duct 19. The heat exchanger 11 is provided with an element filter 11b. The filter 29 and the element filter 11b capture fine particles contained in the outside air (OA). Thereby, the fine particles are captured, and cleaner air (SA) than the outside air (OA) is sent into the room.

[0041] Due to the weather conditions of the outside air (OA), when an alarm is issued such that the PM2.5 exceeds the one-day average value of 35 μg / m 3 of the Japanese environmental standard, or the yellow sand exceeds 200 μg / m 3 it is better to reduce or stop the air volume of the air supply fan 21 and the exhaust fan 23 in order to prevent such air from entering the room.

[0042] Since the air supply passage 18 is provided with the filter 29 and the element filter 11b, even if air exceeding the above environmental standards is taken in, particles are collected by the filter 29 or the like, so the particle concentration of the air actually supplied to the room becomes lower than the above environmental standards, and control such as air volume and fan stop cannot be carried out at an appropriate timing.

[0043] However, by installing the IAQ sensor 31 at a position adjacent to the interior of the room, the particle concentration of the air actually supplied to the room can be measured, so it becomes possible to carry out control such as air volume and fan stop at an appropriate timing.

[0044] Let the number of particles of the fine particles contained in the outside air (OA) be N OA and let the number of particles of the fine particles contained in the air (SA) supplied to the room after passing only the filter 29 through the bypass air passage 20 or both the filter 29 and the element filter 11b through the heat exchanger 11 be N SA Then, the collection efficiency η of the filter is represented by the following formula (1).

[0045]

Equation

[0046] When the filter is functioning normally, since the collection efficiency shows a value equal to or higher than a certain level, the particle concentration of the outside air (OA) can be estimated from the measured value of the IAQ sensor 31. That is, the measured value of the IAQ sensor 31 will vary according to the particle concentration of the outside air (OA). From this, when the measured value of the IAQ sensor 31 becomes, for example, equal to or higher than the first value, the air volume can be decreased, and when it becomes equal to or higher than the second value, the fan can be stopped for control. Note that this control is just an example and is not limited to this.

[0047] These filters used in the ventilation system have a specified particle collection efficiency. Therefore, using the given collection efficiency and the particle concentration of the outdoor air (OA) measured outdoors, the particle concentration of SA can be calculated from Equation 1 above and compared with the particle concentration measured by the IAQ sensor 31 to determine the validity of the measurement value of the IAQ sensor 31.

[0048] The heat exchanger 11 allows heat and moisture to pass through, but due to gaps generated during assembly and differential pressure during operation, etc., a part of the exhaust leaks to the supply air side. This leakage amount can be expressed by an index called the effective ventilation rate (%) of the ventilation system as a product.

[0049] Let the CO2 concentration of the outdoor air (OA) be C OA and the CO2 concentration of the air (SA) supplied to the room after passing through the heat exchanger 11 be C SA and the CO2 concentration of the air (RA) introduced from the exhaust inlet 15 before entering the heat exchanger 11 be C RA Then, the effective ventilation rate e is expressed by the following Equation 2.

[0050]

Equation

[0051] For example, when C OA is 400 ppm, C SA is 500 ppm, and C RA is 1000 ppm, from Equation 2 above, the effective ventilation rate e is approximately 83%.

[0052] When the CO2 concentration in the room increases, the CO2 concentration of RA increases. If the CO2 concentration of the outdoor air (OA) is almost constant, since the effective ventilation rate e is constant, according to Equation 2 above, the CO2 concentration of SA measured by the IAQ sensor 31 will increase. The increase in the CO2 concentration of SA is due to the air leaked in the heat exchanger 11, and the air volume can be controlled to increase by the amount of leakage. Thereby, it becomes possible to lower the CO2 concentration in the room and ensure comfort.

[0053] The control of supply and exhaust air by the ventilation system includes not only the air volume control by the supply fan 21 and the exhaust fan 23, but also the switching of the ventilation mode. Fig. 4 is a diagram for explaining total heat exchange and normal ventilation, that is, mode switching. The ventilation system is provided with a damper 22, and by closing the damper 22, air can flow through the heat exchanger 11, and by opening the damper 22, air can flow around the heat exchanger 11.

[0054] The ventilation mode can be switched according to whether total heat exchange is desired or not. In any case of selecting a mode, since the filter 29 is installed on the supply air inlet 12 side in the supply air duct 18, various particles in the outside air (OA) can be collected, and the air quality of the air (SA) supplied to the room after collecting various particles can be measured by the IAQ sensor 31.

[0055] The ventilation system can include an outdoor temperature sensor for detecting the temperature of the outside air (OA), an outdoor humidity sensor for detecting the relative humidity of the outside air (OA), an indoor temperature sensor for detecting the indoor temperature, and an indoor humidity sensor for detecting the indoor relative humidity. In this case, the temperature and relative humidity of the outside air (OA) introduced from the supply air inlet 12 and the temperature and relative humidity of the indoor air (RA) introduced from the exhaust air inlet 15 can be measured.

[0056] The control circuit 30 calculates the outdoor absolute humidity, outdoor enthalpy, indoor absolute humidity, and indoor enthalpy based on the outside air temperature, outside air relative humidity, indoor temperature, and indoor relative humidity measured by each sensor.

[0057] The control circuit 30 is provided with a storage unit and stores the values of the indoor target temperature, indoor target relative humidity, indoor target absolute humidity, and indoor target enthalpy. The control circuit 30 can switch the ventilation mode based on the indoor enthalpy, the outdoor enthalpy, and the indoor target enthalpy stored in the storage unit.

[0058] For example, when the indoor target enthalpy < outdoor enthalpy < indoor enthalpy, or outdoor enthalpy < indoor target enthalpy < indoor enthalpy, if outdoor air with an enthalpy lower than that of the indoor air is introduced without heat exchange, the indoor enthalpy can be decreased and brought closer to the indoor target enthalpy. Therefore, the normal ventilation mode is adopted.

[0059] When the indoor enthalpy < outdoor enthalpy < indoor target enthalpy, if outdoor air with an enthalpy higher than that of the indoor air is introduced without heat exchange, the indoor enthalpy can be increased and brought closer to the indoor target enthalpy. Therefore, the normal ventilation mode is adopted.

[0060] When the outdoor enthalpy < indoor enthalpy < indoor target enthalpy, by introducing outdoor air with an enthalpy lower than that of the indoor air through heat exchange, the decrease in the indoor enthalpy can be suppressed and brought closer to the indoor target enthalpy. Therefore, the total heat exchange mode is adopted.

[0061] When the indoor target enthalpy < indoor enthalpy < outdoor enthalpy, or indoor enthalpy < indoor target enthalpy < outdoor enthalpy, by introducing outdoor air with an enthalpy higher than that of the indoor air through heat exchange, the increase in the indoor enthalpy can be suppressed and brought closer to the indoor target enthalpy. Therefore, the total heat exchange mode is adopted.

[0062] The control circuit 30 can compare each enthalpy and switch the ventilation mode so as to approach the indoor target enthalpy.

[0063] Here, the ventilation system has been described as having a damper 22 provided on the exhaust air inlet 15 side, and the air (RA) introduced from the exhaust air inlet 15 is caused to flow through the bypass air passage 20 bypassing the heat exchanger 11 or through the heat exchanger 11 by opening and closing the damper 22. However, the present invention is not limited to this. Therefore, the damper 22 may be provided on the supply air inlet 12 side, and the outside air (OA) may be caused to flow through the bypass air passage 20 bypassing the heat exchanger 11 or through the heat exchanger 11 by opening and closing the damper 22.

[0064] In addition to those using the rectangular total heat exchange element 11a shown in Fig. 1(b), there are ventilation systems equipped with a rotary heat exchanger of the rotary rotor type. Fig. 5 is a diagram showing a configuration example of a ventilation system of the rotary rotor type. Similar to the configuration shown in Fig. 1, it has a supply air inlet 12, an exhaust air outlet 13, a supply air outlet 14, and an exhaust air inlet 15, and a supply air passage 18 and an exhaust air passage 19 are formed. A supply air fan 21 is installed in the supply air passage 18, and an exhaust air fan 23 is installed in the exhaust air passage 19. In this example, a damper 22 is provided in the supply air passage 18, and the supply air passage 18 and the exhaust air passage 19 extend linearly.

[0065] In the middle of the supply air passage 18 and the exhaust air passage 19, a circularly rotating total heat exchange element (rotor) 32 is installed as the heat exchanger 11. The rotor 32 is partitioned between the supply air side and the exhaust air side and rotates at a speed of several tens of rpm. In the supply air passage 18, a bypass air passage 20 that bypasses the heat exchanger 11 is provided by opening the damper 22.

[0066] When the damper 22 is closed as shown in Fig. 5(a), the rotary rotor type ventilation system exhausts the indoor air (RA) to the outside as EA by passing it through the lower half of the rotating rotor 32 as shown in Fig. 5(b), and supplies the outside air (OA) to the indoor as SA by passing it through the upper half of the rotor 32. At this time, during the heating period, the heat and moisture of RA are continuously recovered by the rotor 32 and continuously supplied to SA. Also, during the cooling period, the heat and moisture of OA are continuously recovered by the rotor 32, and unnecessary heat and moisture can be continuously removed from SA.

[0067] When the damper 22 is opened as shown in Fig. 5(c), the rotary rotor type ventilation system stops the rotation of the rotor 32, supplies air through the bypass air duct 20, and exhausts air through the lower half of the stationary rotor 32.

[0068] Referring to Fig. 6, an example of the control of the supply and exhaust of the ventilation system will be described. By using a switch, a remote controller, etc. to instruct the start-up of the ventilation system and turn on the power supply, the control starts from step 100. In step 101, the IAQ sensor 31 measures the air quality of SA. In step 102, it is determined whether it is necessary to start the supply fan 21 and the exhaust fan 23.

[0069] If the supply fan 21 and the exhaust fan 23 are already started, there is no need to start. Also, if the air quality measured by the IAQ sensor 31 is below the target value indicating that the air quality is sufficient to ensure comfort, there is no need to start. As an example, when the CO2 concentration of RA reaches 1000 ppm or more and the supply fan 21 and the exhaust fan 23 have not been started yet, it can be determined that it is necessary to start these fans. The CO2 concentration of RA can be estimated from the CO2 concentration measured by the IAQ sensor 31 and the effective ventilation rate e of the heat exchanger 11.

[0070] If it is determined in step 102 that starting is necessary, proceed to step 103 and start the supply fan 21 and the exhaust fan 23.

[0071] In step 104, based on the measurement result of step 101, it is determined whether it is necessary to change the air volume. Whether it is necessary to change the air volume can be determined by the measurement result of the IAQ sensor 31. For example, it can be determined by whether the CO2 concentration has reached a predetermined value or more, and also by whether the particle concentration has reached the above-mentioned first value or more. Since these are just examples, it is not limited to this.

[0072] If it is determined in step 104 that a change is necessary, it proceeds to step 105 to change the air volume. When the CO2 concentration increases, it is considered that the CO2 concentration of the air leaking from the heat exchanger 11 increases. Therefore, in order to take in more outdoor air (OA) with a low CO2 concentration and discharge the indoor air with a high CO2 concentration, the air volume can be increased.

[0073] When the particle concentration increases, it is considered that the particle concentration of the outdoor air (OA) increases. In such a case, the air volume can be decreased in order to reduce the amount of outdoor air (OA) taken into the room.

[0074] In step 106, based on the measurement result of step 101, it is determined whether to stop the supply fan 21 and the exhaust fan 23. When the particle concentration increases and reaches the above-mentioned second value or more, it can be determined to stop.

[0075] If it is determined in step 106 not to stop the supply fan 21 and the exhaust fan, it returns to step 101 and repeats these controls. On the other hand, if it is determined in step 106 to stop the supply fan 21 and the exhaust fan 23, it proceeds to step 107, stops the supply fan 21 and the exhaust fan 23, and returns to step 101.

[0076] The control shown in FIG. 6 continues until the power supply of the ventilation system is cut off or an error occurs. The power supply is cut off by using a switch, a remote controller, etc. to instruct the stop of the ventilation system.

[0077] Referring to FIGS. 7 and 8, a construction example of installing a ventilation system will be described. FIG. 7 shows a first construction example, and FIG. 8 shows a second construction example. In the construction example shown in FIG. 7, ducts 50 and 51 leading to the interior are provided in the ceiling space, and the ducts 50 and 51 are respectively connected to the supply air outlet 14 and the exhaust air inlet 15 of the ventilation system.

[0078] The ventilation system takes in outside air (OA) by the supply air fan 21 and supplies it into the room through the duct 50 connected to the supply air outlet 14. The IAQ sensor 31 is installed at a position adjacent to the interior in the duct 50. The IAQ sensor 31 can also be installed at a position adjacent to the supply air outlet 14 in the supply air duct 18 of the ventilation system. However, since there is a possibility of leakage in the duct 50 as well, it is desirable to install it at a position as close as possible to the interior, adjacent to the interior in the duct 50.

[0079] When the IAQ sensor 31 is installed in the duct 50 separated from the ventilation system, in order to communicate between the IAQ sensor 31 and the ventilation system, it may be connected by a cable or the like to perform wired communication, or it may be connected wirelessly to perform wireless communication.

[0080] In the construction example shown in FIG. 8, the supply air outlet 14 is connected to the indoor unit 52 of the air conditioner by a pipe 53, and the supply air is mixed with the blown air blown out by the indoor unit 52. In such a case, the IAQ sensor 31 can be installed on the indoor unit 52 side in the pipe 53. The IAQ sensor 31 may be installed at the air outlet from which the mixed air of the blown air of the indoor unit 52 and the supply air is blown out. When the IAQ sensor 31 is installed at a position adjacent to the indoor unit 52 or inside the indoor unit 52, the power supply for operating the IAQ sensor 31 can be supplied from the indoor unit 52.

[0081] The communication between the IAQ sensor 31 and the ventilation system may be wired communication or wireless communication, similar to the construction example shown in FIG. 7. Note that the communication between the IAQ sensor 31 and the ventilation system may be directly performed between the IAQ sensor 31 and the ventilation system, or may be performed via the indoor unit 52.

[0082] Since the IAQ sensor 31 is installed in the indoor unit 52 in this way, and ventilation may be performed together with the heating and cooling operation, the present invention can provide not only a ventilation system but also an air conditioner including the indoor unit 52, the outdoor unit, and the ventilation system.

[0083] FIG. 9 is a diagram for explaining the maintenance timing such as cleaning and replacement of the filter 29 and the elements of the heat exchanger 11. When the filter 29 and the element filter 11b of the heat exchanger 11 deteriorate, the particle concentration or the amount of particles in the air quality of SA measured by the IAQ sensor 31 increases.

[0084] FIG. 9 is a graph summarized as time-series data with the elapsed time on the horizontal axis and the CO2 concentration and the amount of particles on the vertical axis. As shown in FIG. 9, both the CO2 concentration and the amount of particles change within a certain range when the filter 29 and the element filter 11b are not deteriorated. However, when they deteriorate, they deviate from that range and increase with the passage of time.

[0085] Therefore, the data in which the amount of particles deviates from that range and reaches an arbitrarily set value surrounded by a circle can be regarded as the data when an abnormality occurs. The time indicated by the data when this abnormality occurs is the time when maintenance is required. From the graph shown in FIG. 9, until the CO2 concentration and the amount of particles start to increase and reach the time when maintenance is required, the CO2 concentration and the amount of particles continue to increase at a substantially constant rate over a predetermined time.

[0086] As shown in FIG. 10, the time when maintenance is required is determined by providing a learning period and examining the tendency as shown in FIG. 9 when maintenance is required from the time-series data. In FIG. 10, since the values of the measurement data show a tendency to continue rising at a constant rate, it can be seen that the time for maintenance is approaching.

[0087] When the time-series data shows such a trend, the values from when the measured data starts to increase until the present are approximated by a straight line and extrapolated, and the time when the value indicates an abnormality can be predicted as the time when maintenance is required. The calculation for this prediction may be performed within the control circuit 30, or the measured data may be transmitted to a remote monitoring system or a cloud system, etc. as an external system that remotely monitors the ventilation system, and the prediction may be performed in the remote monitoring system, etc.

[0088] Note that since the filter does not deteriorate rapidly, for example, several data points can be collected per day and averaged, etc., to keep the memory capacity small.

[0089] When the total heat exchange element 11a deteriorates, the leakage amount increases, and the CO2 concentration measured by the IAQ sensor 31 increases. Therefore, when the CO2 concentration also deviates from a certain range and reaches a value indicating an abnormality, the time when maintenance of the total heat exchange element 11a is required can be predicted by extrapolating the time-series data measured by the IAQ sensor 31.

[0090] Note that the effective ventilation rate e may be calculated from the CO2 concentrations of RA and OA, and it may be confirmed whether there is a change in its value, that is, whether it is within a certain range. When there is a change and it reaches a value indicating an abnormality, the time when maintenance is required may be predicted as the time when maintenance is required.

[0091] Also, the time when maintenance of the filter or the total heat exchange element is required may be predicted by extrapolating from the data collected during operation, or the time when maintenance is required may be predicted using a learned model by performing machine learning using training data. Note that predicting using a learned model can more appropriately predict the time when maintenance is required.

[0092] As described above, according to this control, compared with installing an IAQ sensor between the heat exchanger 11 and the exhaust air inlet 15 in the exhaust air duct 19 to measure the air quality of conventional RA, it is possible to measure the air quality actually supplied into the room, and it becomes possible to operate with appropriate air volume control and ventilation mode. Further, it is possible to detect deterioration and leakage of the filter and the total heat exchange element, and it also becomes possible to predict appropriate maintenance.

[0093] So far, the ventilation system, air conditioner, and control method of the present invention have been described in detail with the above-described embodiments. However, the present invention is not limited to the above-described embodiments, and can be changed within the scope that those skilled in the art can conceive, such as other embodiments, addition, change, deletion, etc. As long as the effects of the present invention are achieved in any aspect, it is included in the scope of the present invention.

Explanation of Reference Numerals

[0094] 10... Box body 11... Heat exchanger 11a... Total heat exchange element 11b... Element filter 12... Supply air inlet 13... Exhaust air outlet 14... Supply air outlet 15... Exhaust air inlet 16, 17... Partition plates 18... Supply air duct 19... Exhaust air duct 20... Bypass duct 21... Supply air fan 22... Damper 23... Exhaust air fan 24... Supply air passage 25... Exhaust air passage 26... Natural evaporation type humidifier 27... Electric heater 28... Direct expansion type heat exchanger 29... Filter 30... Control circuit 31... IAQ sensor 32... Rotor 40... CPU 41…Flash memory 42…RAM 43…Communication I / F 44…Control I / F 45…Bus 50, 51…Duct 52…Indoor unit 53…Pipe

Claims

1. A ventilation system for controlling air supply and exhaust, comprising: An air supply duct having an air supply means for supplying outdoor air into the room; An exhaust duct having an exhaust means for discharging the indoor air to the outside; A heat exchanger disposed in the middle of the air supply duct and the exhaust duct for performing at least heat exchange between the indoor air and the outdoor air; Measuring means installed at a position adjacent to the room on the indoor side of the air supply means for measuring the air quality of the outdoor air after passing through the heat exchanger supplied to the room by the air supply means, wherein the air quality indicates the component amount of a target substance in the indoor air; the measuring means; Control means for controlling the air supply and exhaust by the air supply means and the exhaust means based on the measurement result of the measuring means Including, A ventilation system in which an air supply outlet for blowing out the outdoor air of the ventilation system and an indoor unit of an air conditioner are connected by a pipe, and the measuring means is installed at a position adjacent to the air outlet of the indoor unit.

2. A ventilation system for controlling air supply and exhaust, comprising: An air supply duct having an air supply means for supplying outdoor air into the room; An exhaust duct having an exhaust means for discharging the indoor air to the outside; A heat exchanger disposed in the middle of the air supply duct and the exhaust duct for performing at least heat exchange between the indoor air and the outdoor air; Measuring means installed at a position adjacent to the room on the indoor side of the air supply means for measuring the air quality of the outdoor air after passing through the heat exchanger supplied to the room by the air supply means, wherein the air quality indicates the component amount of a target substance in the indoor air; the measuring means; Control means for controlling the air supply and exhaust by the air supply means and the exhaust means based on the measurement result of the measuring means Including, The control means predicts the maintenance time of the heat exchanger based on the temporal change of the measurement result. A ventilation system.

3. A ventilation system for controlling air supply and exhaust, comprising: An air supply duct having an air supply means for supplying outdoor air into the room; An exhaust duct having an exhaust means for discharging the indoor air to the outside; A heat exchanger disposed in the middle of the air supply duct and the exhaust duct for performing at least heat exchange between the indoor air and the outdoor air; Measuring means that is installed at a position adjacent to the interior of the room on the indoor side of the air supply means and measures the air quality of the outdoor air after passing through the heat exchanger supplied to the room by the air supply means, wherein the air quality indicates the component amount of a target substance in the indoor air; the measuring means Control means for controlling the air supply and exhaust by the air supply means and the exhaust means based on the measurement result of the measuring means including The control means transmits the measurement result to an external system in order to predict the maintenance timing of the heat exchanger; a ventilation system

4. The ventilation system according to claim 2 or 3, wherein the measuring means is installed at a position adjacent to the interior of the room in a pipe connecting the interior of the room and an air supply outlet for blowing out the outdoor air of the ventilation system

5. A bypass air passage that bypasses the heat exchanger; Opening and closing means that opens and closes in response to a ventilation mode so as to open one of an inlet of the bypass air passage and an inlet for passing through the heat exchanger and close the other; Outdoor temperature detection means for detecting the temperature of the outdoor air; Outdoor humidity detection means for detecting the relative humidity of the outdoor air; Indoor temperature detection means for detecting the temperature of the indoor air; Indoor humidity detection means for detecting the relative humidity of the indoor air; Storage means for storing an indoor target enthalpy including The control means calculates the outdoor enthalpy and the indoor enthalpy based on the outside air temperature detected by the outdoor temperature detection means, the outside air relative humidity detected by the outdoor humidity detection means, the indoor temperature detected by the indoor temperature detection means, and the indoor relative humidity detected by the indoor humidity detection means, and performs switching control of the ventilation mode based on the calculated outdoor enthalpy and indoor enthalpy and the indoor target enthalpy stored in the storage means; the ventilation system according to any one of claims 1 to 4

6. The ventilation system according to any one of claims 1 to 5, wherein the measuring means measures the concentration of carbon dioxide in the air

7. The ventilation system according to any one of claims 1 to 6, further including collection means for collecting particles contained in the outdoor air between an air supply inlet for introducing the outdoor air in the air supply passage and the heat exchanger

8. The ventilation system according to claim 7, wherein the measuring means measures the concentration of particles in the air

9. At least one of a humidifier, a heater, and a direct expansion heat exchanger is included on the discharge side of the air supply means between the air supply outlet that blows the outdoor air in the air supply air passage into the room and the heat exchanger. The ventilation system according to any one of claims 1 to 8, wherein the measuring means is installed on the indoor side of at least one of the humidifier, the heater, and the direct expansion heat exchanger.

10. An air conditioner including an indoor unit, an outdoor unit, and a ventilation system connected to the indoor unit, wherein the ventilation system has an air supply air passage provided with air supply means for supplying outdoor air into the room, has an exhaust air passage provided with exhaust means for discharging the indoor air to the outside, has a heat exchanger disposed in the middle of the air supply air passage and the exhaust air passage for performing at least heat exchange between the indoor air and the outdoor air, is measuring means installed at a position adjacent to the air outlet of the indoor unit on the indoor side of the air supply means for measuring the air quality of the outdoor air after passing through the heat exchanger supplied into the room by the air supply means, and the air quality indicates the component amount of the target substance in the indoor air, and the measuring means, and control means for controlling the air supply and exhaust by the air supply means and the exhaust means based on the measurement result of the measuring means An air conditioner comprising.

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