Ventilation system, air conditioning device, and control method

Abstract

The present invention provides a ventilation system, an air conditioning device, and a control method capable of measuring the quality of air actually supplied to a room and appropriately controlling the supply and exhaust of air. The ventilation system includes: an air supply duct equipped with an air supply fan; an exhaust duct; a heat exchanger disposed midway between the air supply duct and the exhaust duct for performing at least heat exchange between indoor air and outdoor air; a bypass duct for supplying outdoor air into the room or exhausting indoor air to the room, bypassing the heat exchanger; a damper for opening either the inlet of the bypass duct or the inlet toward the heat exchanger and closing the other; a first sensor for measuring a state quantity of air introduced into the air supply duct; and a control circuit for correcting the state quantity measured by the first sensor based on the volume of air supplied into the room by the air supply fan, and switching the air supply or exhaust path using the damper based on the corrected state quantity.

Description

Technical Field

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

[0002] Buildings such as residences, mansions, and hospitals are becoming increasingly airtight for energy conservation and comfort reasons. This increased airtightness can lead to the accumulation of pollutants such as water vapor, carbon dioxide, and various odor components generated indoors, which can deteriorate indoor air quality (IAQ). Consequently, ventilation systems are increasingly necessary to maintain good air quality by exhausting these pollutants and bringing in fresh air from outside.

[0003] In recent years, with the trend toward energy conservation, ventilation systems have adopted systems equipped with total heat exchangers that can transfer heat and humidity between supply and exhaust air. The advantages of these systems are becoming increasingly recognized and widespread.

[0004] A heat exchanger is usually equipped with a temperature and humidity sensor inside to compare the temperature and humidity information of the outside air (OA: Outdoor Air) and the air exhausted from the room (RA: Return Air). It is usually controlled by switching between a heat exchange mode in which air is supplied and exhausted through the heat exchanger and a normal ventilation mode in which air is supplied and exhausted bypassing the heat exchanger.

[0005] In the past, the following technologies are known: a technology for switching ventilation modes by using the specific enthalpy between indoor and outdoor spaces, and a technology for switching ventilation modes by using the indoor target specific enthalpy stored in the storage unit in addition to the specific enthalpy between indoor and outdoor spaces, in addition to the indoor target specific enthalpy stored in the storage unit (for example, refer to patent documents 1 and 2).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-071184

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2015-206570 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] However, the above-mentioned prior art fails to consider the effects of heat generation from the air supply fan's motor on the air supply temperature and humidity. Therefore, it is impossible to accurately estimate the changes in the air state after total heat exchange caused by the air supply fan's operation. This reduces the accuracy of air supply and exhaust control.

[0012] Solutions to Problems

[0013] In view of the above problems, the present invention provides a ventilation system for controlling supply and exhaust, comprising:

[0014] An air supply duct including an air supply unit for supplying outdoor air to the indoor space;

[0015] An exhaust air duct having an exhaust unit for discharging indoor air to the outside;

[0016] a heat exchanger disposed midway between the supply air duct and the exhaust air duct and configured to perform at least heat exchange between indoor air and outdoor air;

[0017] A bypass air passage that bypasses the heat exchanger and supplies outdoor air to the room or exhausts indoor air to the room;

[0018] an opening and closing unit that opens one of the inlet of the bypass air passage and the inlet toward the heat exchanger and closes the other;

[0019] a measuring unit that measures a state quantity of air introduced into the air supply duct; and

[0020] The control unit corrects the state quantity measured by the measuring unit according to the air volume supplied into the room by the air supply unit, and switches the air supply or exhaust path by the opening and closing unit based on the corrected state quantity.

[0021] Effects of the Invention

[0022] According to the present invention, the accuracy of air supply and exhaust control can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a diagram showing a first configuration example of the ventilation system.

[0024] Figure 2 This is a diagram showing an example of the hardware configuration of the control circuit.

[0025] Figure 3 This is a diagram illustrating the installation positions of sensors and the theoretical changes in the temperature and humidity of the air in the total heat exchanger.

[0026] Figure 4 This is a diagram illustrating the actual movement of the temperature and humidity of the air in the total heat exchanger.

[0027] Figure 5 This is a diagram for explaining a first example of a conventional method for determining whether to perform mode switching.

[0028] Figure 6 These are diagrams explaining the damper operation in each mode.

[0029] Figure 7 This is a diagram for explaining a first example of the present method for determining whether to perform mode switching.

[0030] Figure 8 This is a flowchart showing an example of this control.

[0031] Figure 9 This is a diagram illustrating a second example of a conventional method for determining whether to perform mode switching.

[0032] Figure 10 This is a diagram for explaining a second example of the present method for determining whether to perform mode switching.

[0033] Figure 11 This is a diagram showing an example of changing the sensor mounting position.

[0034] Figure 12 This is a diagram showing an example of a case where only one sensor is used.

[0035] Figure 13 This is a diagram showing an example of a sensor that measures a state quantity of indoor air.

[0036] Figure 14 It is a diagram showing a second configuration example of the ventilation system.

[0037] In the picture:

[0038] 10 - housing; 11 - heat exchanger; 12 - air supply inlet; 13 - exhaust outlet; 14 - air supply outlet; 15 - exhaust inlet; 16, 17 - partitions; 18 - air supply duct; 19 - exhaust duct; 20 - bypass duct; 21 - exhaust fan; 22 - baffle; 23 - air supply fan; 24 - first sensor; 25 - second sensor; 26 - control circuit; 30 - CPU; 31 - flash memory; 32 - RAM; 33 —Communication I / F; 34—Control I / F; 35—Bus; 40—First sensor; 41—Second sensor; 42—Baffle; 43—Bypass air duct; 44—Heat exchanger; 50—Ventilation system; 51—Remote control for ventilation system; 52—Air conditioning unit; 53—Remote control for air conditioning unit; 54—Communication wiring; 55—External environmental sensor; 60—Direct expansion heat exchanger; 61—Electric heater; 62—Natural evaporation humidifier. DETAILED DESCRIPTION

[0039] Figure 1This diagram shows a first configuration example of a ventilation system according to this embodiment. A ventilation system exchanges indoor and outdoor air to ensure the quality of a building's indoor air. Air quality indicates the amount of target substances in the indoor air. These target substances include carbon dioxide, carbon monoxide, particulate matter such as PM2.5 and PM10, and volatile organic compounds.

[0040] like Figure 1 As shown, the ventilation system includes a housing 10 and a heat exchanger 11 disposed within the housing 10. An air supply inlet 12 for introducing outdoor air (OA) and an exhaust outlet 13 for discharging indoor air as EA (Exhaust Air) to the outside are provided at one longitudinal end of the housing 10. An air supply outlet 14 for supplying air introduced from the air supply inlet 12 to the inside of the room as SA (Supply Air) and an exhaust inlet 15 for drawing indoor air (RA) are provided at the other longitudinal end of the housing 10. Partition plates 16 and 17 are disposed within the housing 10 to form a supply air duct 18 that connects the supply air inlet 12 and the supply air outlet 14 via the heat exchanger 11, and an exhaust air duct 19 that connects the exhaust outlet 13 and the exhaust air inlet 15 via the heat exchanger 11. The supply air duct 18 and the exhaust air duct 19 are formed to intersect within the heat exchanger 11.

[0041] In addition to the air supply duct 18 and the exhaust duct 19, a bypass duct 20 is formed in the housing 10 to bypass the heat exchanger 11 and connect the exhaust outlet 13 and the exhaust inlet 15. The bypass duct 20 is connected to the suction side of an exhaust fan 21 that is located on the outdoor side of the heat exchanger 11 and is disposed in the exhaust duct 19. The bypass duct 20 is provided with a damper 22 as an opening and closing unit that opens and closes toward the exhaust inlet 15. 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 by bypassing the heat exchanger 11. In addition, in Figure 1 In the example, the bypass air passage 20 on the air supply inlet 12 side is open in the air supply passage 18, but this means that the bypass air passage 20 is connected to the suction side of the exhaust fan 21, and there is no part in the middle that closes the bypass air passage 20. Therefore, if the outside air introduced from the air supply inlet 12 does not enter the bypass air passage 20, the exhaust gas flowing in the bypass air passage 20 will not leak into the air supply passage 18, and the supply air and the outside air will not mix in this part. This is explained below. Figure 3 The same is true for etc.

[0042] An air supply fan 23 is provided in the air supply duct 18 as an air supply unit for introducing outdoor air (OA) into the room. The air supply fan 23 is provided between the heat exchanger 11 and the air supply outlet 14 in the air supply duct 18 .

[0043] The exhaust fan 21 is provided between the heat exchanger 11 and the exhaust outlet 13 in the exhaust air passage 19 as exhaust means for exhausting the indoor air (RA) to the outside.

[0044] Heat exchanger 11 may be a sensible heat exchanger that exchanges only heat between air flowing through supply air duct 18 and air flowing through exhaust air duct 19, or a total heat exchanger that exchanges not only heat but also moisture (humidity). Hereinafter, heat exchanger 11 will be described as a total heat exchanger.

[0045] The total heat exchanger includes a total heat exchange element. Each of the elements is rectangular. With respect to the longitudinal direction of the housing 10, one of the four corners formed by two adjacent side surfaces of the element is located on the housing 10, another is located on the bypass air passage 20, and the remaining two are located adjacent to one end of each of the partition plates 16 and 17.

[0046] The total heat exchange element is made of paper, nonwoven fabric, resin, or other materials and comprises multiple layers. The supply air passages, which form part of the supply air duct 18, and the exhaust air passages, which form part of the exhaust air duct 19, are arranged in a staggered, overlapping pattern at approximately 90° angles. Thus, starting from the top, the total heat exchange element alternates between supply air passages in the first layer, which extend from 0° to 180°; exhaust passages in the second layer, which extend from 90° to 270°; and supply passages in the third layer, which extend from 0° to 180° again. This allows heat and moisture to pass through the paper, etc., while also separating the supply and exhaust air, preventing them from mixing.

[0047] The ventilation system can operate in conjunction with an air conditioning system comprising an indoor unit and an outdoor unit. Alternatively, the ventilation system can operate in conjunction with the indoor and outdoor units, forming part of the air conditioning system. The ventilation system's supply air outlet 14 is connected to the indoor unit via a pipe, allowing air to be blown into the indoor unit. This allows the indoor unit to mix indoor air drawn in by the indoor fan with air blown out of the supply air outlet 14, and blow the resulting mixture into the room.

[0048] The ventilation system includes a first sensor 24 that measures the temperature (dry-bulb temperature) and humidity (relative humidity: RH) of the outside air (OA) introduced from the supply air inlet 12 as state quantities, and a second sensor 25 that measures the temperature and humidity of the indoor air (RA) introduced from the exhaust air inlet 15 as state quantities. The first sensor 24 is located within the supply air duct 18 between the heat exchanger 11 and the supply air inlet 12, while the second sensor 25 is located within the exhaust air duct 19 between the heat exchanger 11 and the exhaust air inlet 15. While the first and second sensors 24 and 25 measure temperature and humidity as state quantities, they can also measure carbon dioxide concentration, particle concentrations such as PM2.5, and other similar quantities.

[0049] The ventilation system includes a control circuit 26 as a control unit. The control circuit 26 is connected to the exhaust fan 21, the damper 22, the supply air fan 23, the first sensor 24, and the second sensor 25. Based on the temperature, humidity, and carbon dioxide concentration measured by the first and second sensors 24 and 25, the control circuit 26 controls the air volume of the supply and exhaust fans 23 and 21. The ventilation mode is switched by opening and closing the damper 22. It should be noted that the sensor for measuring carbon dioxide and other parameters can also serve as an air quality (IAQ) sensor and be installed separately from the first and second sensors 24 and 25, for example, between the supply air fan 23 and the supply air outlet 14.

[0050] The ventilation mode includes a full heat exchange mode in which the damper 22 is closed and exhaust is exhausted through the heat exchanger 11 ; and a normal ventilation mode in which the damper 22 is opened and exhaust is exhausted through the bypass air passage 20 while bypassing the heat exchanger 11 .

[0051] The control circuit 26 calculates the theoretical SA state quantity after full heat exchange or when bypassing the heat exchanger 11 based on the state quantities such as temperature and humidity measured by the first sensor 24 and the second sensor 25. The calculated air state quantities include the dry-bulb temperature and specific enthalpy of the SA.

[0052] While the ventilation system is described herein as being configured such that the damper 22 is positioned on the exhaust air inlet 15 side, and the air (RA) introduced from the exhaust air inlet 15 by opening and closing the damper 22 bypasses the heat exchanger 11 and flows through the bypass air passage 20, or flows through the heat exchanger 11, the present invention is not limited thereto. Therefore, a configuration may also be employed in which the damper 22 is positioned on the supply air inlet 12 side, and the outside air (OA) is directed to bypass the heat exchanger 11 by opening and closing the damper 22 and flow through the bypass air passage 20, or flows through the heat exchanger 11. Furthermore, the ventilation system may include an element filter in the heat exchanger 11, or a filter as a collection unit may be provided in the supply air passage 18 to collect particulate matter such as PM2.5 and pollen contained in the outside air introduced from the supply air inlet 12.

[0053] Conventionally, the optimal ventilation pattern was determined based on the theoretical SA state quantity. However, the theoretical SA state quantity does not represent the actual SA state quantity. This is because the supply air fan 23 is installed between the heat exchanger 11 and the supply air outlet 14, and the SA state quantity changes due to heat generated by the motor of the supply air fan 23, etc.

[0054] Therefore, the control circuit 26 corrects the theoretical SA state quantity using the heat generated by the components between the heat exchanger 11 and the supply air outlet 14, thereby inferring the actual SA state quantity. Based on the inferred actual SA state quantity, the optimal ventilation mode is determined. This allows accurate estimation of the air state change after full heat exchange, enabling highly precise control such as switching ventilation modes.

[0055] The control circuit 26 has the same structure as the control circuit of the outdoor unit of the air conditioner. Figure 2 As shown, the system includes a CPU 30 , a flash memory 31 , a RAM (Random Access Memory) 32 , a communication I / F 33 , and a control I / F 34 . Components such as the CPU 30 are connected to a bus 35 , and information and the like are exchanged via the bus 35 .

[0056] The CPU 30 controls the entire ventilation system. Flash memory 31 stores programs and various data used by the CPU 30 for control. RAM 32 provides a workspace for the CPU 30. The communication I / F 33 receives air quality information from the IAQ sensor. The control I / F 34 connects to the air supply fan 23, damper 22, and exhaust fan 21 to control each component.

[0057] Here, the control circuit 26 realizes the calculation of the air state, mode switching, and other controls by the CPU 30 reading a program from the flash memory 31 and executing the program. However, the present invention is not limited thereto and may be realized using dedicated hardware such as a circuit.

[0058] Figure 3 (a) is a diagram illustrating the sensor installation position. In the conventional mode control in the ventilation system with a conventional total heat exchanger, Figure 3 A first sensor 40 and a second sensor 41 are provided at the position shown in (a). When damper 42 is closed and total heat exchange is being performed, the air state quantities (also referred to as OA air information and RA air information) measured by these sensors and the exchange efficiencies of all heat exchange elements constituting the total heat exchanger, stored in advance in a memory unit such as a flash memory included in the control circuit, can be used to calculate the SA state quantity after total heat exchange (also referred to as SA air information). On the other hand, when damper 42 is opened, air is allowed to flow through bypass air passage 43, and total heat exchange is not being performed, the OA air information can be used directly as the SA air information.

[0059] The SA air information after full heat exchange or the SA air information of normal ventilation without full heat exchange is sent as the air information of the air blown out from the ventilation system to the air conditioning device linked to the ventilation system, so that the air conditioning device performs appropriate cooling and heating operations to control the system.

[0060] Figure 3 (b) is a diagram illustrating the theoretical movement of the temperature and humidity of the air in the total heat exchanger. Air information refers to the temperature and humidity of the air. The air line diagram is a diagram used to analyze the state changes of the air using any two of the state quantities such as dry bulb temperature, relative humidity, water vapor partial pressure, absolute humidity, specific enthalpy, dew point temperature, wet bulb temperature as coordinate axes. Figure 3 In (b), the two coordinate axes are the dry-bulb temperature (°C) on the horizontal axis and the absolute humidity (kg / kg) on ​​the vertical axis.

[0061] Dry-bulb temperature (°C) is the temperature of air as measured by a typical thermometer. Relative humidity (%) expresses the actual amount of water vapor contained in air relative to the maximum amount of water vapor that can be contained in air at a given temperature. In this specification, unless otherwise specified, temperature refers to dry-bulb temperature and humidity refers to relative humidity.

[0062] Water vapor partial pressure (Pa) is the pressure of water vapor in air. Absolute humidity (kg / kg) indicates the amount of water vapor (kg) contained in 1 kg of moist air relative to 1 kg of dry air. Specific enthalpy (kJ / kg) is the enthalpy (kJ) possessed by 1 kg of a substance.

[0063] The dew point temperature (°C) is the temperature at which air becomes saturated and condensation occurs when cooled. The wet bulb temperature (°C) is the lowest temperature at which a surface wet with water evaporates and is cooled in the presence of wind.

[0064] Figure 3 The air line diagram shown in (b) has curves representing relative humidity and straight lines connecting each point on the curve representing specific enthalpy with each dry bulb temperature and each absolute humidity. Therefore, if the dry bulb temperature and relative humidity are known, the absolute humidity and specific enthalpy can be calculated. Figure 3 In (b), OA air information and RA air information refer to the points indicated by "OA" and "RA," while "SA" and "EA" represent SA air information and EA air information calculated using the exchange efficiency of the total heat exchange element. Outside air drawn into the system from the point indicated by "OA" moves toward the point indicated by "SA," and air drawn from the room into the system from the point indicated by "EA" moves toward the point indicated by "RA."

[0065] Theoretically, the air state changes as follows Figure 3 The actual SA air information changes as shown in (b), but the actual SA air information changes from the theoretical SA air information due to heat generation of the air supply fan motor, etc.

[0066] The OA air information and the RA air information are the air information measured by the first sensor 40 and the second sensor 41. However, the air information of the air actually blown into the room (SA) is the air information that takes the heat of the motor into consideration compared to the theoretical SA air information. Specifically, Figure 4 As shown, while the absolute humidity remains constant from point "SA," the dry-bulb temperature and specific enthalpy increase to point "SA*." Similarly, the air information for the air (EA) exhausted to the outside due to heat generation from the exhaust fan 21 motor, etc., also takes into account motor heat generation, etc., and point "EA" also reaches the state of point "EA*," where the dry-bulb temperature and specific enthalpy increase. Since the EA and EA* air information have no impact on indoor air conditioning, their description is omitted below.

[0067] In order to send appropriate mode switching and accurate blown air information to the control units of other linked devices and perform optimal air conditioning system control, it is necessary to consider the heat generated by the air supply fan motor and correct the SA air information based on the heat generated.

[0068] A common method for switching modes is as follows: when the linked air conditioner is in cooling operation, if the outside air temperature is greater than the indoor temperature or the outside air specific enthalpy is greater than the indoor specific enthalpy, the full heat exchange mode is used to reduce the load of introducing outside air. If the outside air temperature is less than the indoor temperature or the outside air specific enthalpy is less than the indoor specific enthalpy, the outside air is introduced directly without heat exchange to cool the indoor environment, and the normal ventilation mode is used. In this method, during heating operation, if the outside air temperature is greater than the indoor temperature or the outside air specific enthalpy is greater than the indoor specific enthalpy, the normal ventilation mode is used to heat the indoor environment by introducing outside air directly without heat exchange. If the outside air temperature is less than the indoor temperature or the outside air specific enthalpy is less than the indoor specific enthalpy, the full heat exchange mode is used to minimize indoor cooling caused by ventilation.

[0069] Figure 5 This diagram illustrates a first example of a conventional method for determining whether to switch ventilation modes during heating operation during cooling operation. The appropriate mode can be determined by determining whether the point representing these two air states falls within the full heat exchange mode or the normal ventilation mode range using the RA temperature or RA specific enthalpy included in the RA air information and the OA temperature or OA specific enthalpy included in the OA air information measured by the first sensor 40 and the second sensor 41.

[0070] By the way, it is rare to have extreme situations such as excessive cooling during cooling operation and excessive temperature change during heating operation, and normal ventilation. Figure 5 (a) is mainly the case of refrigeration operation, Figure 5 (b) is mainly the case of heating operation.

[0071] Figure 6 These are diagrams for explaining the operation of the damper 42 in each mode. Figure 6 (a) shows the operation of the damper 42 in the full heat exchange mode. The damper 42 closes the inlet of the bypass air passage 43 and opens the inlet of the heat exchanger 44. Thus, in the full heat exchange mode, the indoor air is exhausted to the outside through the heat exchanger 44.

[0072] Figure 6 (b) shows the operation of the damper 42 in the normal ventilation mode, opening the inlet of the bypass air passage 43 and closing the inlet of the heat exchanger 44 with the damper 42. Thus, in the normal ventilation mode, the indoor air is discharged to the outside by bypassing the heat exchanger 44.

[0073] Figure 5The diagram used for mode determination is a conventional diagram that does not take into account heat generation from the air supply fan motor, etc. When motor heat generation is taken into account, the SA air state is corrected based on the heat generation value, and the resulting SA* air information is compared with the RA air information to make a mode determination.

[0074] Figure 7 This is a diagram illustrating a first example of the present method for determining whether to switch the ventilation mode during the heating operation in the case of cooling operation. Figure 1 The first sensor 24 and the second sensor 25 shown obtain RA air information and OA air information, calculate SA air information based on the RA air information, OA air information and the exchange efficiency of the heat exchanger 11, and correct the SA air information with the heat generated by the motor of the air supply fan 23, etc. to obtain SA* air information.

[0075] By using the temperature or specific enthalpy of SA* contained in the SA* air information and the temperature or specific enthalpy of RA contained in the RA air information, it is possible to determine in which range of the full heat exchange mode and the normal ventilation mode the points represented by these two air states are located, thereby determining the appropriate ventilation mode.

[0076] Here, regarding the calculation of SA* and the heat generation amount of the air supply fan 23 , the following equations 1 and 2 hold true.

[0077] Formula 1

[0078]

[0079] Formula 2

[0080]

[0081] The above-mentioned equations 1 and 2 can be rewritten as the following equations 3 and 4.

[0082] Formula 3

[0083] T SA =T OA -Eff sen (T OA -T RA ) (Formula 3)

[0084] Formula 4

[0085] H SA =H OA -Eff H (H OA -H RA ) (Formula 4)

[0086] In the above formula 3 and formula 4, T OA is the dry bulb temperature of OA (℃), TRA is the dry bulb temperature of RA (℃). OA is the specific enthalpy of OA (kJ / kg(DA)), H RA is the specific enthalpy of RA (kJ / kg(DA)). All specific enthalpies are the specific enthalpy per unit mass of dry air (DA). sen is the sensible heat exchange efficiency (%), Eff H is the total heat exchange efficiency (%). In addition, T SA is the dry bulb temperature of SA (°C), H SA is the specific enthalpy of SA (kJ / kg(DA)).

[0087] If the temperature correction amount due to the heat generated by the air supply fan 23 is ΔT i (°C), the specific enthalpy correction amount due to the heat generated by the air supply fan 23 is denoted as ΔH i (kJ / kg(DA)), the actual dry bulb temperature (℃) after the correction of SA is set as T SA *, the actual specific enthalpy (kJ / kg(DA)) of the corrected SA is set to H SA *, then T SA * can be expressed as the following formula 5, H SA *Can be expressed as the following formula 6.

[0088] Formula 5

[0089] T SA * =T SA +ΔT i (Formula 5)

[0090] Formula 6

[0091] H SA * =H SA +ΔH i (Formula 6)

[0092] If the air supply fan 23 has a step-by-step airflow pattern, such as "high," "medium," and "low," the temperature correction and specific enthalpy correction values ​​described above can be pre-determined for each airflow pattern and stored in the memory unit. Thus, the correction value corresponding to the current airflow pattern can be read from the memory unit and applied to Equations 5 and 6 to calculate the actual dry-bulb temperature and actual specific enthalpy of SA.

[0093] In addition, when using Figure 7When determining the ventilation mode, the specific enthalpy can be used as a comparison reference, but it is not limited to this. When no specific enthalpy information is obtained and no calculation unit is provided, only the dry-bulb temperature information is used, and only the actual dry-bulb temperature T of SA is calculated by the above formula 3 and formula 5. SA *.

[0094] Reference Figure 8 The ventilation mode switching control is now explained. When the ventilation system is powered on, the ventilation system starts, and this control begins at step 100. The air supply fan 23 and exhaust fan 21 start, and the first sensor 24 and second sensor 25 begin operating. In practice, air quality measurement and fan air volume control are also performed, but here, only the ventilation mode switching control is explained.

[0095] In step 101, the first sensor 24 and the second sensor 25 measure the state quantities of OA and RA. Examples of the state quantities of OA and RA are the temperature and humidity of OA and RA. In step 102, the state quantity of SA is calculated using the state quantities of OA and RA and the exchange efficiency of the heat exchanger 11. For example, the specific enthalpy of SA is calculated using Equation 4 above.

[0096] In step 103, the state quantity of SA is corrected and the state quantity of SA* is calculated. In step 104, the ventilation mode is determined based on the state quantity of SA*. For example, refer to Figure 7 The ventilation pattern can be determined using the state quantity of RA and the calculated state quantity of SA*.

[0097] In step 105, it is determined whether the ventilation mode needs to be switched. Whether the ventilation mode needs to be switched can be determined based on whether the currently set and running ventilation mode is different from the determined ventilation mode. If the currently set ventilation mode is different from the determined ventilation mode and it is determined that the ventilation mode needs to be switched, the process proceeds to step 106 and switches to the determined ventilation mode. If it is determined in step 105 that the ventilation mode does not need to be switched, after switching the ventilation mode in step 106, the process returns to step 101 and repeats until the power supply of the ventilation system is cut off. In addition, control can be stopped not only when the power is cut off, but also when the administrator stops the system or an error occurs in the system.

[0098] In the above description, the actual specific enthalpy of SA is calculated by using the OA air information and the RA air information measured by the first sensor 24 and the second sensor 25 according to the above equations 4 and 6, and referring to Figure 7 Furthermore, as described above, when it is difficult to obtain specific enthalpy information, the dry-bulb temperature may be used as a comparison reference for control.

[0099] Air conditioners and other equipment are equipped with remote controls to allow users to freely set target temperatures. Ventilation systems also incorporate the concept of indoor target values, similar to those used in these devices. These systems set target indoor specific enthalpy and target indoor dry-bulb temperature, and control the system based on these values. Below, we'll use the indoor target specific enthalpy as an example of an indoor target value.

[0100] In this method, the indoor target specific enthalpy is stored in a storage unit. The outdoor specific enthalpy is calculated based on the outdoor temperature and relative humidity obtained from the first sensor 24, and the indoor specific enthalpy is calculated based on the indoor temperature and relative humidity obtained from the second sensor 25. The ventilation mode is determined based on the indoor specific enthalpy, the outdoor specific enthalpy, and the indoor target specific enthalpy stored in the storage unit. For details of this method, please refer to the aforementioned Patent Document 2. The storage unit storing the indoor target specific enthalpy may be the same storage unit as the storage unit storing the correction amount, etc., or a separate storage unit.

[0101] In this method, when the indoor target specific enthalpy is less than the outdoor specific enthalpy and less than the indoor specific enthalpy, or when the outdoor specific enthalpy is less than the indoor target specific enthalpy and less than the indoor specific enthalpy, if the outdoor air having a lower specific enthalpy than the indoor air is not heat exchanged and introduced, the indoor specific enthalpy can be reduced and approached to the indoor target specific enthalpy, and therefore the normal ventilation mode is set.

[0102] When indoor specific enthalpy < outdoor specific enthalpy < indoor target specific enthalpy, if outdoor specific enthalpy higher than the indoor specific enthalpy is introduced without heat exchange, the indoor specific enthalpy can be increased to approach the indoor target specific enthalpy, so the normal ventilation mode is set.

[0103] When outdoor specific enthalpy < indoor specific enthalpy < indoor target specific enthalpy, heat exchange is performed to introduce outside air with a lower specific enthalpy than the indoor air, which can suppress the decrease in indoor specific enthalpy and approach the indoor target specific enthalpy. Therefore, the full heat exchange mode is set.

[0104] When the indoor target specific enthalpy is less than the indoor specific enthalpy and less than the outdoor specific enthalpy, or when the indoor specific enthalpy is less than the indoor target specific enthalpy and less than the outdoor specific enthalpy, the increase in the indoor specific enthalpy can be suppressed and the indoor target specific enthalpy can be approached by performing heat exchange. Therefore, the full heat exchange mode is set.

[0105] In this way, the specific enthalpies are compared and the ventilation mode is switched so as to approach the target specific enthalpy in the room.

[0106] Figure 9This figure illustrates a second conventional example of determining whether to switch modes. The horizontal axis represents the specific enthalpy of RA, and the vertical axis represents the specific enthalpy of OA. The horizontal and vertical axes, along with three straight lines passing through the origin of slope 1, are represented by dashed lines. Regions A1-A3 defined by the three dashed lines represent the normal ventilation mode, while regions B1-B3 represent the full heat exchange mode.

[0107] This mode determination may be inappropriate because it does not take into account the heat generated by the air supply fan 23. The following examples will be used to describe the inappropriate situation.

[0108] The specific enthalpy of OA and the specific enthalpy of RA are calculated from the air line diagram using the dry bulb temperature and relative humidity measured by the first sensor 24 and the second sensor 25. The indoor target specific enthalpy and the exchange efficiency Eff of the heat exchanger 11 are stored in the storage unit. sen 、Eff H .

[0109] For example, the air conditions at a certain moment are: the specific enthalpy of OA is 48 (kJ / kg(DA)), the specific enthalpy of RA is 49 (kJ / kg(DA)), the target indoor specific enthalpy is 50 (kJ / kg(DA)), and the exchange efficiency is 50 (%). Substituting these values ​​into the above formula 4, H in the full heat exchange mode is calculated. SA When H SA =48.5(kJ / kg(DA)). In normal ventilation mode, H SA =H OA , so H SA =48(kJ / kg(DA)). RA is 49(kJ / kg(DA)), so H SA and H RA The determined corresponding condition point falls within the region B2, and the full heat exchange mode is determined.

[0110] However, when performing actual optimal control, the heat generated by the air supply fan 23 must be considered. The correction amount considering the heat generation is set to ΔH i = 2, the actual specific enthalpy of SA* H SA *In full heat exchange mode, H is obtained by the above formula 6. SA *=48.5+2=50.5, in normal ventilation mode, H SA * = 48 + 2 = 50. When the two are compared, the normal ventilation mode is advantageous in that the indoor target specific enthalpy is the same as 50 (kJ / kg (DA)).

[0111] This shows that the conventional mode determination that does not take into account the heat generated by the air supply fan 23 cannot provide optimal control.

[0112] Therefore, a different control standard is adopted that takes into account the heat generated by the air supply fan 23 . Figure 10 This figure illustrates a second example of the present method for determining whether to switch modes. The vertical axis represents the corrected specific enthalpy of SA* in the total heat exchange mode, and the horizontal axis represents the corrected specific enthalpy of SA* in the normal ventilation mode. Regions A1-A4, defined by four dashed lines, represent the normal ventilation mode region, while regions B1-B4 represent the total heat exchange mode region.

[0113] The target SA specific enthalpy is stored in the storage unit instead of the indoor target specific enthalpy. The target SA specific enthalpy stored in the storage unit is compared with the corrected specific enthalpy of SA* in the total heat exchange mode and the corrected specific enthalpy of SA* in the normal ventilation mode to perform mode switching control (damper control).

[0114] The specific enthalpy of SA* in each ventilation mode after correction can be calculated from the dry bulb temperature and relative humidity of OA and the dry bulb temperature and relative humidity of RA measured by the first sensor 24 and the second sensor 25. The specific enthalpy of OA and RA can be calculated using the exchange efficiency Eff H Calculate H using the above formula 4 SA , is calculated by the above-mentioned formula 6 using the correction amount stored in the storage unit.

[0115] When the above example is applied in this method, in full heat exchange mode H SA *=50.5, in normal ventilation mode H SA *=50, so the corresponding condition point is within the region B1, and the optimal ventilation mode is determined to be the full heat exchange mode.

[0116] By setting the relationship between the air volume pattern and the heat generation of the air supply fan 23 for each model at the design stage and storing it in the storage unit, it is possible to cope with the case where a different type of fan is used.

[0117] Thus, the correction amount corresponding to each air volume mode when the air volume of the air supply fan 23 is increased or decreased by switching the air volume mode is stored in advance in the storage unit, and the correction amount corresponding to the actual air volume mode is read out to calculate H in each ventilation mode. SA Therefore, the fan heat generation can be measured by a sensor, and the H value under each ventilation mode can be calculated by correction based on the measured value. SA *Specific enthalpy.

[0118] In addition, the installation positions of the first sensor 24 and the second sensor 25 are not limited to between the air supply inlet 12 and the heat exchanger 11 in the air supply duct 18 and between the exhaust inlet 15 and the heat exchanger 11 in the exhaust duct 19. Figure 11As shown, the first sensor 24 may also be disposed between the heat exchanger 11 and the air supply fan 23 in the air supply duct 18 .

[0119] In this case, the dry bulb temperature and relative humidity of the air (SA) after passing through the heat exchanger 11 are measured by the first sensor 24, so it is not necessary to calculate T using the above formula 3 and formula 4. SA 、H SA Therefore, T can be calculated only by using the above equations 5 and 6. SA *、H SA *.

[0120] In addition, the air supply fan 23 is not limited to a fan that performs step-by-step control of increasing and decreasing the air volume in an air volume mode. Therefore, the air supply fan 23 can also be a fan that can continuously change the air volume and perform continuous increase and decrease control of the air volume. In this case, as a parameter corresponding to the air volume, the fan speed is detected by a sensor that detects the fan speed, and the relationship between the ventilation volume and the fan speed is used to calculate the correction amount corresponding to the air volume. In this way, the calculated correction amount can be used to make corrections and calculate the H in each ventilation mode. SA *Specific enthalpy.

[0121] In the above description, two sensors, the first sensor 24 and the second sensor 25, are provided, and the measurement results of the two sensors are used to perform calculations to calculate H in each ventilation mode for determining the ventilation mode. SA However, it is not necessary to have sensors at two locations in the ventilation system. As long as the indoor air (RA) information can be obtained, it is sufficient. Figure 12 As shown in (a) and (b), a configuration in which only the first sensor 24 is provided in the ventilation system may also be adopted.

[0122] Figure 12 (a) shows a case where the first sensor 24 is provided between the supply air inlet 12 and the heat exchanger 11 in the supply air passage 18 , and the air information of the OA can be measured by the first sensor 24 . Figure 12 (b) shows a case where the first sensor 24 is provided between the heat exchanger 11 and the air supply fan 23 in the air supply duct 18 , and the air information of SA can be directly measured by the first sensor 24 .

[0123] As an alternative to the second sensor 25, Figure 13As shown in (a), a sensor built into a ventilation system remote controller 51 for operating the ventilation system 50 or an air conditioning device remote controller 53 for operating a linked air conditioning device 52 can be used. The ventilation system 50 and the air conditioning device 52 are connected via a communication connection 54. When the sensor built into the air conditioning device remote controller 53 measures indoor air information, the ventilation system 50 can obtain the measurement results via the air conditioning device 52 and the communication connection 54.

[0124] In addition, if Figure 13 As shown in (b), indoor air information can also be measured by an external environmental sensor 55 that is not connected to the ventilation system remote controller 51 or the air conditioning device remote controller 53 but is capable of communicating with the ventilation system 50. The external environmental sensor 55 is a sensor that measures air quality and can measure temperature, humidity, carbon dioxide concentration, carbon monoxide concentration, formaldehyde, volatile organic compounds (VOCs), PM2.5, pollen, and sand.

[0125] Communication between the ventilation system 50 and the ventilation system remote controller 51, and between the air conditioner 52 and the air conditioner remote controller 53, can be wireless communication using infrared or other means. Communication between the ventilation system 50 and the air conditioner 52 is not limited to wired communication using the communication cable 54; wireless communication using Bluetooth (registered trademark), WiFi (registered trademark), or the like is also possible. Furthermore, communication between the ventilation system 50 and the external environment sensor 55 can also be achieved using any communication method, whether wired or wireless.

[0126] By using alternative sensors in this manner, the number of sensors mounted on the ventilation system can be reduced, thereby reducing the number of manufacturing steps and costs of the components.

[0127] While the correction amount has been described as being relative to the heat generated by the air supply fan 23, the correction amount is not limited to the fan heat generation. In some cases, other components may be provided between the heat exchanger 11 and the air supply outlet 14 within the air supply duct 18, and the correction amount may be relative to the heat generated by such components.

[0128] Figure 14 It is a diagram showing a second configuration example of the ventilation system according to this embodiment. Figure 14 The structure shown is Figure 1The structure shown is roughly the same, but a direct expansion heat exchanger 60, an electric heater 61, and a natural evaporation humidifier 62 are provided as other components in the air supply duct 18. The direct expansion heat exchanger 60 is a heat exchanger that directly exchanges heat with the air used in the air conditioning device, and includes a heat transfer tube (coil) for the flow of refrigerant for heat exchange with the air. The natural evaporation humidifier 62 includes a vaporization section such as a filter and pottery and a water storage section. The water storage section stores water, and the vaporization section absorbs water from the water storage section through capillary action and naturally vaporizes it, thereby humidifying. Here, a natural evaporation humidifier is illustrated, but it is not limited to this. A steam type humidifier that uses an electric heater to heat water and generate steam for humidification, an ultrasonic type humidifier that uses an ultrasonic generator to vibrate water and spray it in a mist for humidification, or a hybrid type humidifier that has an electric heater and an ultrasonic generator can also be used.

[0129] The electric heater 61 is a device for increasing the temperature of the air information SA. The direct expansion heat exchanger 60 and the natural evaporation humidifier 62 are devices for changing the temperature and humidity of the air information SA.

[0130] Similarly, when there are other components between the heat exchanger 11 and the air supply outlet 14 in the air supply duct 18 in addition to the air supply fan 23, the correction amount can be pre-stored in the storage unit, or a sensor can be installed on the component to directly measure the heat, etc., and the correction amount corresponding to the measurement result can be calculated through calculation.

[0131] When the air supply fan 23 and other components are provided between the heat exchanger 11 and the air supply outlet 14 in the air supply duct 18 , correction can be performed by a correction amount corresponding to the sum of the heat generated by the air supply fan 23 and the heat generated by the other components.

[0132] exist Figure 14 In the figure, an example of three components is shown, but the present invention is not limited thereto and may include one, two, or four or more components.

[0133] As described above, this control allows efficient mode switching by estimating accurate supply air temperature and specific enthalpy, taking into account changes in the temperature and specific enthalpy of air after total heat exchange caused by the operation of the supply air fan, etc.

[0134] So far, the ventilation system, air-conditioning device and control method of the present invention have been described in detail with the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments. It can be changed in other embodiments, additions, changes, deletions, etc. within the scope that can be thought of by those skilled in the art. In any way, as long as the function and effect of the present invention are achieved, it is included in the scope of the present invention.

Claims

1. A ventilation system that controls the supply and exhaust of air. The ventilation system is characterized by comprising: An air supply duct including an air supply unit for supplying outdoor air to the indoor space; An exhaust air duct having an exhaust unit for discharging indoor air to the outside; a heat exchanger disposed midway between the supply air duct and the exhaust air duct and configured to at least exchange heat between the indoor air and the outdoor air; a bypass air passage that bypasses the heat exchanger and supplies the outdoor air to the indoor room or exhausts the indoor air to the outdoor room; an opening and closing unit that opens one of the inlet of the bypass air passage and the inlet toward the heat exchanger and closes the other; a first measuring unit for measuring a state quantity of air introduced into the air supply duct; a second measuring unit for measuring a state quantity of air introduced from the room into the exhaust air passage; as well as a control unit that uses the state quantity measured by the first measuring unit and the state quantity measured by the second measuring unit to calculate the state quantity of air after passing through the heat exchanger, corrects the calculated state quantity of air after passing through the heat exchanger based on the air volume supplied to the room by the air supply unit and the heat generated by the motor of the air supply unit, and switches the air supply or exhaust path using the opening and closing unit based on the corrected state quantity of air after passing through the heat exchanger.

2. The ventilation system according to claim 1, characterized in that A correction amount storage unit is included, the correction amount storage unit storing a correction amount corresponding to the air volume of each stage of the air supply unit that switches the air volume in stages, The control unit acquires the correction amount corresponding to the stage of the air volume of the air supply unit from the correction amount storage unit, and corrects the state amount of the air after passing through the heat exchanger using the acquired correction amount.

3. The ventilation system according to claim 1, characterized in that A detection unit is included, the detection unit detecting a parameter corresponding to the air volume of the air supply unit that continuously switches the air volume, The control unit calculates a correction amount based on the parameter detected by the detection unit, and corrects a state quantity of air after passing through the heat exchanger using the calculated correction amount.

4. The ventilation system according to any one of claims 1 to 3, characterized in that: A target value storage unit is included, wherein the target value storage unit stores the target value of the indoor state quantity, The control unit switches the air supply or exhaust path using the opening and closing unit based on the corrected state quantity of the air after passing through the heat exchanger and the target value stored in the target value storage unit.

5. The ventilation system according to any one of claims 1 to 3, characterized in that: The first measuring unit is provided between the heat exchanger and the air supply unit in the air supply duct.

6. The ventilation system according to any one of claims 1 to 3, characterized in that: The second measuring unit is installed in any one of a device operating device for operating the device installed in the room, a ventilation system operating device for operating the ventilation system, and an air quality measuring device installed in the room to measure the air quality in the room.

7. The ventilation system according to any one of claims 1 to 3, characterized in that: The air supply unit, and the humidifying unit or the heating unit or both are provided in the air supply duct. In addition to the air volume supplied to the indoor room by the air supply unit, the state quantity of the air after passing through the heat exchanger is corrected according to the humidifying amount of the humidifying unit or the heating amount of the heating unit or both.

8. An air conditioning device comprising an indoor unit, an outdoor unit, and a ventilation system connected to the indoor unit. The air conditioning device is characterized in that The ventilation system comprises: An air supply duct including an air supply unit for supplying outdoor air to the indoor space; An exhaust air duct having an exhaust unit for discharging indoor air to the outside; a heat exchanger disposed midway between the supply air duct and the exhaust air duct and configured to at least exchange heat between the indoor air and the outdoor air; a bypass air passage that bypasses the heat exchanger and supplies the outdoor air to the indoor room or exhausts the indoor air to the outdoor room; an opening and closing unit that opens one of the inlet of the bypass air passage and the inlet toward the heat exchanger and closes the other; a first measuring unit for measuring a state quantity of air introduced into the air supply duct; a second measuring unit for measuring a state quantity of air introduced from the room into the exhaust air passage; as well as a control unit that uses the state quantity measured by the first measuring unit and the state quantity measured by the second measuring unit to calculate the state quantity of air after passing through the heat exchanger, corrects the calculated state quantity of air after passing through the heat exchanger based on the air volume supplied to the room by the air supply unit and the heat generated by the motor of the air supply unit, and switches the air supply or exhaust path using the opening and closing unit based on the corrected state quantity of air after passing through the heat exchanger.

9. A control method is a method for controlling the supply and exhaust of air using a ventilation system, characterized in that: The ventilation system comprises: An air supply duct including an air supply unit for supplying outdoor air to the indoor space; An exhaust air duct having an exhaust unit for discharging indoor air to the outside; a heat exchanger disposed midway between the supply air duct and the exhaust air duct and configured to at least exchange heat between the indoor air and the outdoor air; a bypass air passage that bypasses the heat exchanger and supplies the outdoor air to the indoor room or exhausts the indoor air to the outdoor room; an opening and closing unit that opens one of the inlet of the bypass air passage and the inlet toward the heat exchanger and closes the other; a first measuring unit; a second assay unit; and control unit, The control method includes: The first measuring unit measures the state quantity of air introduced into the air supply duct by the air supply unit; The second measuring unit measures the state quantity of air introduced from the room into the exhaust air duct; and The control unit uses the state quantity measured by the first measuring unit and the state quantity measured by the second measuring unit to calculate the state quantity of air after passing through the heat exchanger, corrects the calculated state quantity of air after passing through the heat exchanger according to the air volume supplied to the room by the air supply unit and the heat generated by the motor of the air supply unit, and based on the corrected state quantity of air after passing through the heat exchanger, uses the opening and closing unit to switch the air supply or exhaust path.

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