Heat exchange ventilation system

Abstract

This invention provides a technology for determining whether or not the internal air circulation is functioning correctly in internal air circulation mode. [Solution] The outside air sensor 60 measures the outside air temperature of the outside air chamber 22 and outputs the measured outside air temperature to the control unit 70. The return air sensor 62 measures the return air temperature and outputs the measured return air temperature to the control unit 70. In heat exchange mode, the control unit 70 opens the outside air damper 40 and the exhaust damper 42 and closes the central damper 44. In internal circulation mode, the control unit 70 closes the outside air damper 40 and the exhaust damper 42 and opens the central damper 44. In internal circulation mode, the control unit 70 detects an abnormality or malfunction in any of the outside air damper 40, exhaust damper 42, or central damper 44 based on the outside air temperature and the return air temperature.

Description

Technical Field

[0001] The present disclosure relates to a heat exchange type ventilation device.

Background Art

[0002] The heat exchange type ventilation device has a heat exchange element that performs heat exchange between the high-temperature air inside the room and the low-temperature air outside the room, a blower that sends the high-temperature air to the outside, and a blower that sends the low-temperature air to the inside. In order to prevent freezing of such a heat exchange type ventilation device, an opening is provided in the partition between the low-temperature air passage and the high-temperature air passage, and dampers are provided at each of the low-temperature air suction port, the high-temperature air exhaust port, and the opening. By the opening and closing functions of each damper, the high-temperature air passing through the heat exchange element is guided to the opening, and the high-temperature air inside the room is prevented from mixing into the low-temperature air and being returned to the room (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Due to a damper failure or the like for blocking outside air, there is a possibility that the internal air is not circulating even though it is in the internal air circulation mode. Therefore, it is required to determine whether the internal air is correctly circulating in the internal air circulation mode.

[0005] Therefore, the present disclosure solves the above problems and aims to provide a technique for determining whether the internal air is correctly circulating in the internal air circulation mode.

Means for Solving the Problems

[0006] To solve the above problems, a heat exchange ventilation system according to one embodiment of the present disclosure comprises a housing having an outside air port, an air supply port, a return air port, and an exhaust port; an outside air chamber connected to the outside air port within the housing; an air supply chamber connected to the air supply port within the housing; a return air chamber connected to the return air port within the housing; an exhaust chamber connected to the exhaust port within the housing; a heat exchange element that performs heat exchange between an air supply air passage connecting the outside air chamber and the air supply chamber and an exhaust air passage connecting the return air chamber and the exhaust chamber within the housing; an outside air damper capable of opening and closing the outside air port; an exhaust damper capable of opening and closing the exhaust port; a central damper disposed between the outside air chamber and the exhaust chamber and capable of opening and closing the space between the outside air chamber and the exhaust chamber; a control unit that controls the outside air damper, the exhaust damper, and the central damper; an outside air sensor that measures the outside air temperature in the outside air chamber and outputs the measured outside air temperature to the control unit; and a return air sensor that measures the return air temperature in the return air chamber and outputs the measured return air temperature to the control unit. In heat exchange mode, the control unit opens the outside air damper and exhaust damper and closes the central damper. In internal circulation mode, the control unit closes the outside air damper and exhaust damper and opens the central damper. In internal circulation mode, the control unit detects an abnormality or malfunction in any of the outside air damper, exhaust damper, or central damper based on the outside air temperature and return air temperature.

[0007] Another aspect of the present disclosure is also a heat exchange ventilation system. This system comprises a housing having an outside air inlet, an air supply inlet, a return air inlet, and an exhaust port; an outside air chamber connected to the outside air inlet within the housing; an air supply chamber connected to the air supply inlet within the housing; a return air chamber connected to the return air inlet within the housing; an exhaust chamber connected to the exhaust port within the housing; a heat exchange element that performs heat exchange between an air supply air passage connecting the outside air chamber and the air supply chamber and an exhaust air passage connecting the return air chamber and the exhaust chamber within the housing; an outside air damper capable of opening and closing the outside air inlet; an exhaust damper capable of opening and closing the exhaust port; a central damper positioned between the outside air chamber and the exhaust chamber and capable of opening and closing the space between the outside air chamber and the exhaust chamber; a control unit that controls the outside air damper, the exhaust damper, and the central damper; and an outside air sensor that measures the outside air temperature in the outside air chamber and outputs the measured outside air temperature to the control unit. In heat exchange mode, the control unit opens the outside air damper and exhaust damper and closes the central damper. In internal circulation mode, the control unit closes the outside air damper and exhaust damper and opens the central damper. In internal circulation mode, the control unit detects an abnormality or malfunction in either the outside air damper, exhaust damper, or central damper based on the outside air temperature at a first timing and the outside air temperature at a second timing that occurs after the first timing.

[0008] Furthermore, any combination of the above components, as well as any conversion of the expressions of this disclosure between methods, apparatus, systems, recording media, computer programs, etc., are also valid forms of this disclosure. [Effects of the Invention]

[0009] According to this disclosure, it is possible to determine whether or not the internal air circulation is functioning correctly in internal air circulation mode. [Brief explanation of the drawing]

[0010] [Figure 1] Figures 1(a)-(d) show the configuration of the heat exchange ventilation system according to Example 1. [Figure 2] This diagram shows the data structure of the table used in the control unit shown in Figures 1(a)-(d). [Figure 3]Figures 3(a)-(c) show damper failures (abnormalities) in the heat exchange ventilation system shown in Figure 1(d). [Figure 4] This is a flowchart showing the processing procedure using the heat exchange ventilation system according to Example 1. [Figure 5] This flowchart shows the fault detection and control procedure using a heat exchange ventilation system according to Example 1. [Figure 6] This figure shows an overview of equipment protection control using a heat exchange ventilation system according to Example 2. [Figure 7] This flowchart shows the equipment protection control procedure using a heat exchange ventilation system according to Example 2. [Figure 8] This is a flowchart showing the processing procedure using the heat exchange ventilation system according to Example 2. [Figure 9] This flowchart shows the fault detection and control procedure using a heat exchange ventilation system according to Example 2. [Modes for carrying out the invention]

[0011] The embodiments of this disclosure will be described below with reference to the drawings. Each embodiment described below represents a preferred specific example of this disclosure. Therefore, the numerical values, shapes, materials, components, arrangement and connection configurations of components, as well as the steps (processes) and the order of steps shown in the following embodiments are examples and are not intended to limit this disclosure. Accordingly, components in the following embodiments that are not described in the independent claims representing the highest-level concepts of this disclosure will be described as arbitrary components. In addition, substantially identical components are denoted by the same reference numerals in each figure, and redundant explanations are omitted or simplified.

[0012] (Example 1) Figures 1(a)-(d) show the configuration of the heat exchange ventilation system 100. The heat exchange ventilation system 100 includes a housing 10, an outside air port 12, an air supply port 14, a return air port 16, an exhaust port 18, a heat exchange element 30, an outside air damper 40, an exhaust damper 42, a central damper 44, an air supply fan 50, an exhaust fan 52, an outside air sensor 60, a return air sensor 62, and a control unit 70.

[0013] The enclosure 10 is a structure having a roughly box-like shape and an internal space. An outside air inlet 12 and an exhaust air inlet 18 are located on one side of the enclosure 10 (hereinafter referred to as the "first side"), and an air supply inlet 14 and a return air inlet 16 are located on the opposite side of the enclosure 10 from the first side (hereinafter referred to as the "second side"). Here, the outside air inlet 12 and the return air inlet 16 face each other, and the exhaust air inlet 18 and the air supply inlet 14 face each other. A duct (hereinafter referred to as the "outside air duct") is connected to the outside air inlet 12, and a duct (hereinafter referred to as the "exhaust duct") is connected to the exhaust air inlet 18. The outside air duct and the exhaust duct are connected to openings in the exterior walls of the building. A duct (hereinafter referred to as the "supply air duct") is connected to the air supply inlet 14, and a duct (hereinafter referred to as the "return air duct") is connected to the return air inlet 16. The supply air duct and the ventilation duct are connected to openings in the ceiling or walls of rooms inside the building.

[0014] A box-shaped heat exchange element 30 is housed inside the housing 10, and the inside of the housing 10 is divided into four spaces centered around the heat exchange element 30. The four spaces are the outside air chamber 22, the supply air chamber 24, the return air chamber 26, and the exhaust air chamber 28. The outside air chamber 22 is connected to the outside air port 12 and one side of the heat exchange element 30 (hereinafter referred to as the "first side") inside the housing 10. The supply air chamber 24 is connected to the supply air port 14 and one side of the heat exchange element 30 (hereinafter referred to as the "second side") inside the housing 10. The return air chamber 26 is connected to the return air port 16 and one side of the heat exchange element 30 (hereinafter referred to as the "third side") inside the housing 10. The exhaust air chamber 28 is connected to the exhaust port 18 and one side of the heat exchange element 30 (hereinafter referred to as the "fourth side") inside the housing 10. Here, the outside air chamber 22 and the exhaust chamber 28 are arranged side by side, and the supply air chamber 24 and the return air chamber 26 are arranged side by side. Also, the outside air chamber 22 and the return air chamber 26 are arranged side by side, and the supply air chamber 24 and the exhaust chamber 28 are arranged side by side.

[0015] The first surface and the second surface of the heat exchange element 30 are opposite surfaces to each other, and the third surface and the fourth surface are opposite surfaces to each other. The heat exchange element 30 performs heat exchange between the air supply passage 200 connecting the outside air chamber 22 and the air supply chamber 24 and the exhaust passage 202 connecting the return air chamber 26 and the exhaust chamber 28 in the housing 10.

[0016] An outside air damper 40 is provided in the outside air chamber 22. The outside air damper 40 is a damper capable of opening and closing the outside air port 12. The outside air damper 40 includes a stepping motor and is communicable with a control unit 70 described later. The outside air damper 40 opens and closes by rotating the stepping motor according to an instruction received from the control unit 70. Incidentally, when the outside air damper 40 does not rotate the stepping motor according to an instruction received from the control unit 70, but the stepping motor of the outside air damper 40 is controlled by the control unit 70 described later, it opens and closes by rotating the stepping motor according to an output instruction from the control unit 70.

[0017] An exhaust damper 42 is provided in the exhaust chamber 28. The exhaust damper 42 is a damper capable of opening and closing the exhaust port 18. The exhaust damper 42 includes a stepping motor and is communicable with a control unit 70 described later. The exhaust damper 42 opens and closes by rotating the stepping motor according to an instruction received from the control unit 70. Incidentally, when the exhaust damper 42 does not rotate the stepping motor according to an instruction received from the control unit 70, but the stepping motor of the exhaust damper 42 is controlled by the control unit 70 described later, it opens and closes by rotating the stepping motor according to an output instruction from the control unit 70.

[0018] An opening is provided in the wall between the outside air chamber 22 and the exhaust chamber 28, and a central damper 44 is provided at the opening portion. The central damper 44 is a damper capable of opening and closing the opening in the wall between the outside air chamber 22 and the exhaust chamber 28. The central damper 44 includes a stepping motor and is communicable with a control unit 70 described later. The central damper 44 opens and closes by rotating the stepping motor according to an instruction received from the control unit 70. Note that, if the stepping motor of the central damper 44 is not rotated according to an instruction received from the control unit 70, but is controlled by the control unit 70 described later, it opens and closes by rotating the stepping motor according to an output instruction from the control unit 70.

[0019] An air supply fan 50 is installed in the air supply chamber 24. The air supply fan 50 generates an air supply flow from the outside air chamber 22 toward the air supply chamber 24. The air supply flow flows through the air supply air passage 200. The air supply fan 50 includes, for example, a sirocco fan which is a centrifugal impeller for boosting air pressure, and the air supply flow is generated by the rotation of the sirocco fan. An exhaust fan 52 is installed in the exhaust chamber 28. The exhaust fan 52 generates an exhaust flow from the recirculation chamber 26 toward the exhaust chamber 28. The exhaust flow flows through the exhaust air passage 202. The exhaust fan 52 includes, for example, a sirocco fan which is a centrifugal impeller for boosting air pressure, and the exhaust flow is generated by the rotation of the sirocco fan.

[0020] An outside air sensor 60 is installed in the outside air chamber 22. The outside air sensor 60 measures the temperature of the outside air chamber 22 (hereinafter referred to as "outside air temperature"). The outside air sensor 60 is communicable with the control unit 70 and transmits the measured outside air temperature to the control unit 70. A recirculation air sensor 62 is installed in the recirculation chamber 26. The recirculation air sensor 62 measures the temperature of the recirculation chamber 26 (hereinafter referred to as "recirculation air temperature"). The recirculation air sensor 62 is communicable with the control unit 70 and transmits the measured recirculation air temperature to the control unit 70.

[0021] The control unit 70 can communicate with the outside air damper 40, the exhaust damper 42, the central damper 44, the supply air fan 50, the exhaust fan 52, the outside air sensor 60, and the return air sensor 62. The control unit 70 receives the outside air temperature from the outside air sensor 60 and the return air temperature from the return air sensor 62. The control unit 70 also controls the supply air fan 50, the exhaust fan 52, the outside air damper 40, the exhaust damper 42, and the central damper 44.

[0022] The operation of the heat exchange ventilation system 100, controlled by the control unit 70, includes heat exchange mode, supply mode, exhaust mode, and internal circulation mode. The heat exchange mode is a mode in which heat exchange is performed between the exhaust flow and the supply air flow when outside air is taken in as the supply air flow. The supply mode is a mode in which outside air is taken in as the supply air flow when it is desired to prevent the room from becoming negatively pressurized due to the operation of a range hood or the like. The exhaust mode is a mode in which indoor air is simply sent out as the exhaust flow in situations in which it is not desired to take in outside air, such as during a wildfire. The internal circulation mode is a mode in which the heat exchange elements 30 and other components inside the heat exchange ventilation system 100 are prevented from freezing by eliminating temperature unevenness in each room and by not taking in outside air during low-temperature protection operation.

[0023] The control unit 70 switches modes by referring to the table shown in Figure 2. Figure 2 shows the data structure of the table used in the control unit 70. In heat exchange ventilation mode, the control unit 70 operates the heat exchange ventilation system 100, operates the supply fan 50 and the exhaust fan 52, opens the outside air damper 40 and the exhaust damper 42, and closes the central damper 44. As a result, a supply air passage 200 is formed from the outside air port 12 to the supply air port 14, and an exhaust air passage 202 is formed from the return air port 16 to the exhaust port 18, as shown in Figure 1(a). This allows heat exchange between the supply airflow and the exhaust airflow to occur in the heat exchange element 30.

[0024] In supply air mode, the control unit 70 operates the heat exchange ventilation system 100, operates the supply air fan 50, stops the exhaust fan 52, opens the outside air damper 40, and closes the exhaust damper 42 and the central damper 44. As a result, a supply air passage 200 is formed from the outside air outlet 12 to the supply air outlet 14, as shown in Figure 1(b), and the exhaust air passage 202 is not formed.

[0025] In exhaust mode, the control unit 70 operates the heat exchange ventilation system 100, stops the supply fan 50, operates the exhaust fan 52, closes the outside air damper 40 and the central damper 44, and opens the exhaust damper 42. As a result, an exhaust air passage 202 is formed from the return air port 16 to the exhaust port 18, as shown in Figure 1(c), and the supply air passage 200 is not formed.

[0026] In internal circulation mode, the control unit 70 operates the heat exchange ventilation system 100, operates the supply fan 50 and exhaust fan 52, closes the outside air damper 40 and exhaust damper 42, and opens the central damper 44. As a result, as shown in Figure 1(d), an exhaust air passage 202 is formed that goes from the return air port 16 to the exhaust chamber 28, the exhaust air passage 202 further goes to the outside air chamber 22, and a supply air passage 200 is formed that goes from the outside air chamber 22 to the supply air port 14. In standby mode, the control unit 70 stops the heat exchange ventilation system 100, stops the supply fan 50 and exhaust fan 52, and closes the outside air damper 40 and exhaust damper 42.

[0027] When the internal circulation mode is executed, the outside air damper 40 and the exhaust damper 42 should be closed and the central damper 44 should be opened, as shown in Figure 1(d). However, if the outside air damper 40 (the stepping motor of the outside air damper 40) is faulty or malfunctioning, it will remain open instead of closed. The same can happen to the exhaust damper 42 (the stepping motor of the exhaust damper 42) and the central damper 44 (the stepping motor of the central damper 44). In other words, even if the control unit 70 is controlling the outside air damper 40 and the exhaust damper 42 to close, they may be open due to a fault or malfunction. Similarly, even if the control unit 70 is controlling the central damper 44 to open, it may be open due to a fault or malfunction. In these situations, even if the control unit 70 controls the opening and closing of the outside air damper 40, the exhaust damper 42, and the central damper 44 to execute the internal circulation mode, the actual operation of the heat exchange ventilation system 100 will not be in internal circulation mode.

[0028] Figures 3(a)-(c) show damper failures (abnormalities) in the heat exchange ventilation system 100. Figure 3(a) shows the outside air damper 40 open and the central damper 44 closed. In other words, both the outside air damper 40 and the central damper 44 are in a faulty or abnormal state. Figure 3(b) shows the outside air damper 40 open. In other words, both the outside air damper 40 are in a faulty or abnormal state. Figure 3(c) shows the outside air damper 40 and the exhaust damper 42 open. In other words, both the outside air damper 40 and the exhaust damper 42 are in a faulty or abnormal state. The patterns of failure (abnormality) of the outside air damper 40, exhaust damper 42, and central damper 44 are not limited to these. Return to Figure 1(d).

[0029] Considering these conditions, it is desirable to detect the open / closed state of the outside air damper 40, exhaust damper 42, and central damper 44 when in internal circulation mode. In conventional heat exchange ventilation systems, for example, a physical switch could be provided on the motor used to move the dampers, allowing the physical switch to detect the open / closed state of the dampers. However, as mentioned above, in order to reduce costs, the outside air damper 40, etc., according to this embodiment does not have a physical switch. Therefore, in this embodiment, by monitoring the temperature inside the heat exchange ventilation system 100, it is possible to detect whether the outside air damper 40, exhaust damper 42, and central damper 44 are in an appropriate state without the need for a physical switch.

[0030] In internal circulation mode, the control unit 70 detects an abnormality or malfunction in either the outside air damper 40, the exhaust damper 42, or the central damper 44 based on the outside air temperature from the outside air sensor 60 and the return air temperature from the return air sensor 62. Since the return air sensor 62 is installed in the return air chamber 26, the return air temperature measured by the return air sensor 62 will be close to the room temperature (hereinafter referred to as "room temperature"). On the other hand, the outside air sensor 60 is installed inside the outside air damper 40 in the outside air chamber 22. Therefore, when the outside air damper 40 is closed as shown in Figure 1(d), the outside air temperature measured by the outside air sensor 60 will be close to either the return air temperature or the room temperature. However, when the outside air damper 40 is open as shown in Figures 3(a)-(c), the outside air temperature measured by the outside air sensor 60 will be close to the temperature outside the building (hereinafter referred to as "outdoor temperature"). Therefore, it is possible to detect an abnormality or malfunction based on the difference between the return air temperature and the outside air temperature.

[0031] The control unit 70 provisionally detects a malfunction (abnormality) when the ambient temperature is below a predetermined temperature (e.g., 0°C) and the result of subtracting the ambient temperature from the return air temperature is greater than a threshold (e.g., 10°C) for a predetermined period of time (e.g., 10 minutes) in the internal circulation mode. Alternatively, the control unit 70 may provisionally detect a malfunction (abnormality) when the ambient temperature is below a predetermined temperature (e.g., 0°C) and the result of subtracting the ambient temperature from the return air temperature is greater than a threshold (e.g., 10°C) after a predetermined period of time has elapsed since entering internal circulation mode. In this case, the control unit 70 resets the ambient air damper 40, exhaust damper 42, and central damper 44 and switches to the airflow path of the mode prior to internal circulation mode. Subsequently, the control unit 70 switches back to internal circulation mode and repeatedly performs processing based on the return air temperature and ambient air temperature. The control unit 70 confirms a malfunction (abnormality) when the above conditions (hereinafter referred to as "abnormal conditions") persist even after repeating such processing several times. On the other hand, the control unit 70 determines that the outside air damper 40, exhaust damper 42, and central damper 44 are functioning normally if the abnormal conditions are not met.

[0032] In other words, in internal circulation mode, the control unit 70 detects an abnormality or malfunction in any of the outside air damper 40, exhaust damper 42, or central damper 44 if the result of subtracting the outside air temperature from the return air temperature is greater than a threshold value. This corresponds to determining an abnormality or malfunction when there is a large discrepancy between the return air temperature and the outside air temperature, even though it is in internal circulation mode. A large discrepancy between the return air temperature and the outside air temperature indicates that cold outside air is flowing into the room.

[0033] When the control unit 70 detects an abnormality or malfunction, it causes the stepping motors of the outside air damper 40, exhaust damper 42, and central damper 44 to return to their home positions. Since the return of the stepping motors to their home positions is a well-known technique, a detailed explanation is omitted here. Subsequently, the control unit 70 controls the outside air damper 40, etc., to enter internal circulation mode. Alternatively, when the control unit 70 detects an abnormality or malfunction, it may execute exhaust mode by closing the outside air damper 40 and central damper 44 and opening the exhaust damper 42.

[0034] The heat exchange ventilation system 100 may include a notification unit (not shown). The notification unit is connected, for example, to a network (not shown) and to a communication device (not shown) via the network. When the control unit 70 detects an abnormality or malfunction, it instructs the notification unit to transmit an error code, and the notification unit transmits the error code to the communication device to notify the abnormality or malfunction.

[0035] The subject of the apparatus, system, or method in this disclosure comprises a computer. The functions of the subject of the apparatus, system, or method in this disclosure are realized by the computer executing a program. The computer comprises a processor as its main hardware component, which operates according to the program. The processor is of any type as long as it can realize its functions by executing the program. The processor consists of one or more electronic circuits, including semiconductor integrated circuits (ICs) or LSIs (Large Scale Integrations). Multiple electronic circuits may be integrated on one chip or provided on multiple chips. Multiple chips may be aggregated in one device or provided on multiple devices. The program is recorded on a non-temporary recording medium such as a ROM, optical disc, or hard disk drive that is readable by the computer. The program may be pre-stored on the recording medium or supplied to the recording medium via a wide-area communication network, including the Internet.

[0036] The operation of the heat exchange ventilation system 100 with the above configuration will now be explained. Figure 4 is a flowchart of the processing procedure by the heat exchange ventilation system 100. As a prerequisite, the heat exchange ventilation system 100 has been switched from heat exchange mode to internal circulation mode by manual operation by the user. The outside air sensor 60 performs sampling of the outside air temperature (S10). The control unit 70 performs fault detection control if the outside air temperature is 0°C or lower (Y in S12) (S14). On the other hand, the control unit 70 skips fault detection control if the outside air temperature is not 0°C or lower (N in S12) (S14).

[0037] Figure 5 is a flowchart showing the fault detection control procedure by the heat exchange ventilation system 100. This corresponds to the fault detection control in step S14 of Figure 4. If the operating air duct is not in internal circulation mode (N in S50), the process returns to the flowchart in Figure 4. If the operating air duct is in internal circulation mode (Y in S50), after a predetermined time has elapsed, the control unit 70 obtains the outside air temperature and the return air temperature (S52). If the difference between the return air temperature and the outside air temperature is not greater than 10°C (N in S54), the control unit 70 determines that it is normal (S56) and returns to the flowchart in Figure 4.

[0038] If the difference between the return air temperature and the ambient air temperature is greater than 10°C (Y in S54), and a certain period of time has elapsed (Y in S58), the control unit 70 provisionally detects a fault and performs a retry determination (S60). If a retry has already been performed (Y in S62), the control unit 70 confirms the fault (S64). If a certain period of time has not elapsed (N in S58), or if a retry has not already been performed (N in S62), the process returns to the flowchart in Figure 4. Note that the number of retry determinations may be one or multiple times (for example, three times).

[0039] According to this embodiment, in internal circulation mode, an abnormality or malfunction in any of the outside air damper 40, exhaust damper 42, or central damper 44 is detected based on the outside air temperature and the return air temperature, so it is possible to determine whether or not internal air circulation is functioning correctly in internal circulation mode. Furthermore, in internal circulation mode, if the result of subtracting the outside air temperature from the return air temperature is greater than a threshold value, an abnormality or malfunction in any of the outside air damper 40, exhaust damper 42, or central damper 44 is detected, so it is possible to determine whether or not internal air circulation is functioning correctly in internal circulation mode.

[0040] Furthermore, if an abnormality or malfunction is detected, the stepping motors of the outside air damper 40, exhaust damper 42, and central damper 44 are returned to their home positions, thereby resolving the abnormality or malfunction. Also, if an abnormality or malfunction is detected, the exhaust mode is executed, suppressing the intake of outside air. Furthermore, since the intake of outside air is suppressed, the temperature drop can be suppressed. Furthermore, since the intake of outside air is suppressed, freezing of the heat exchange element 30, etc., can be suppressed. Also, if an abnormality or malfunction is detected, an abnormality or malfunction is notified, so the user can be informed of the occurrence of an abnormality or malfunction.

[0041] An overview of one aspect of this disclosure is as follows: (Item 1) A housing (10) having an outside air inlet (12), an air intake inlet (14), a return air inlet (16), and an exhaust inlet (18), Within the housing (10), there is an outside air chamber (22) connected to the outside air port (12), Within the housing (10), there is an air supply chamber (24) connected to the air supply port (14), Within the housing (10), there is a return air chamber (26) connected to the return air port (16), Within the housing (10), there is an exhaust chamber (28) connected to the exhaust port (18), In the housing (10), a heat exchange element (30) performs heat exchange between an air supply passage (200) connecting the outside air chamber (22) and the air supply chamber (24), and an exhaust passage (202) connecting the return air chamber (26) and the exhaust chamber (28). An outside air damper (40) that can open and close the outside air vent (12), An exhaust damper (42) that can open and close the exhaust port (18), A central damper (44) is positioned between the outside air chamber (22) and the exhaust chamber (28), and is capable of opening and closing the space between the outside air chamber (22) and the exhaust chamber (28). A control unit (70) that controls the outside air damper (40), the exhaust damper (42), and the central damper (44), An outside air sensor (60) measures the outside air temperature of the outside air chamber (22) and outputs the measured outside air temperature to the control unit (70), The system includes a return air sensor (62) that measures the return air temperature in the return air chamber (26) and outputs the measured return air temperature to the control unit (70), In the heat exchange mode, the control unit (70) opens the outside air damper (40) and the exhaust damper (42), and closes the central damper (44). The control unit (70), in the case of internal circulation mode, closes the outside air damper (40) and the exhaust damper (42), and opens the central damper (44). The control unit (70) is a heat exchange ventilation system (100) that, in the case of internal circulation mode, detects an abnormality or malfunction in any of the outside air damper (40), the exhaust damper (42), or the central damper (44) based on the outside air temperature and the return air temperature.

[0042] (Item 2) The control unit (70) detects an abnormality or malfunction in any of the outside air damper (40), the exhaust damper (42), or the central damper (44) in the case of internal circulation mode, according to item 1, when the result of subtracting the outside air temperature from the return air temperature is greater than a threshold.

[0043] (Item 5) Each of the aforementioned outside air damper (40), exhaust damper (42), and central damper (44) has a stepping motor. The heat exchange ventilation device (100) according to item 1 or 2, wherein the control unit (70) causes the stepping motor to return to its home position when it detects an abnormality or malfunction in any of the outside air damper (40), the exhaust damper (42), or the central damper (44).

[0044] (Item 6) The heat exchange ventilation device (100) according to item 1 or 2, wherein the control unit (70) detects an abnormality or malfunction in any of the outside air damper (40), the exhaust damper (42), or the central damper (44), and executes an exhaust mode by closing the outside air damper (40) and the central damper (44) and opening the exhaust damper (42).

[0045] (Item 7) The heat exchange ventilation system (100) according to item 1 or 2, further comprising a notification unit that notifies of an abnormality or malfunction when the control unit (70) detects an abnormality or malfunction in any of the outside air damper (40), the exhaust damper (42), or the central damper (44).

[0046] (Example 2) Next, we will describe Example 2. Example 2 relates to a heat exchange type ventilation system 100 similar to that of Example 1. The heat exchange type ventilation system 100 according to Example 1 is equipped with an outside air sensor 60 and a return air sensor 62. On the other hand, the heat exchange type ventilation system 100 according to Example 2 is equipped with an outside air sensor 60 but is not equipped with a return air sensor 62. Here, we will mainly explain the differences from the previous examples.

[0047] The heat exchange ventilation system 100 according to Example 2 has the same configuration as shown in Figures 1(a)-(d), but does not have a return air sensor 62 as described above. Furthermore, the heat exchange ventilation system 100 is capable of performing equipment protection control (freeze prevention protection control) to prevent freezing of the heat exchange element 30, etc. The equipment protection control (freeze prevention protection control) is performed by the control unit 70 when the outside air temperature measured by the outside air sensor 60 falls to, for example, -5°C or below.

[0048] Figure 6 shows an overview of the equipment protection control by the heat exchange ventilation system 100. The horizontal axis represents time. The control unit 70 performs equipment protection control by repeatedly executing one cycle, which consists of a combination of the heat exchange ventilation mode and the internal circulation mode. In equipment protection control, the internal circulation mode is executed periodically, so the temperature inside the heat exchange ventilation system 100 rises, preventing freezing of the heat exchange elements 30, etc. However, if a malfunction or abnormality occurs in the outside air damper 40, etc., the temperature inside the heat exchange ventilation system 100 will not rise. Therefore, as in Example 1, it is desirable to detect the open / closed state of the outside air damper 40, exhaust damper 42, and central damper 44 when the internal circulation mode is active.

[0049] In the case of internal circulation mode, the control unit 70 detects an abnormality or malfunction in one of the outside air damper 40, exhaust damper 42, or central damper 44 based on the outside air temperature at the time the internal circulation mode is started (hereinafter referred to as the "start temperature") and the outside air temperature at a predetermined time after the start of the internal circulation mode. If the time when the internal circulation mode is started is called the "first timing," then the timing after a predetermined time has elapsed after the start of the internal circulation mode is called the "second timing." Here, the control unit 70 detects the open / closed state of the outside air damper 40, exhaust damper 42, and central damper 44 by detecting a state in which the temperature inside the heat exchange ventilation system 100 does not rise despite the execution of equipment protection control based on the difference between the start temperature and the outside air temperature.

[0050] In the internal circulation mode of equipment protection control, the control unit 70 provisionally detects a fault (abnormality) if the result of subtracting the start temperature from the ambient temperature remains below a threshold (e.g., 5°C) for a predetermined period of time (e.g., 10 minutes). Furthermore, in the internal circulation mode of equipment protection control, the control unit 70 provisionally detects a fault (abnormality) if the result of subtracting the start temperature from the ambient temperature remains below a threshold (e.g., 5°C) after a predetermined period of time has elapsed since the start of internal circulation mode. At this time, the control unit 70 resets the ambient air damper 40, exhaust damper 42, and central damper 44, and switches to the heat exchange airflow path as shown in Figure 6. Subsequently, the control unit 70 switches to internal circulation mode as shown in Figure 6 and repeatedly performs processing based on the ambient temperature and the start temperature. The control unit 70 confirms a fault (abnormality) if the above conditions (hereinafter referred to as "abnormal conditions") persist even after repeating this processing several times. In Figure 6, a fault (abnormality) is tentatively detected at timings P1 and P2, and the fault (abnormality) is confirmed at timing P3. On the other hand, the control unit 70 determines that the outside air damper 40, exhaust damper 42, and central damper 44 are normal if the abnormality conditions are not met.

[0051] In other words, in the case of internal circulation mode, the control unit 70 detects an abnormality or malfunction in any of the outside air damper 40, exhaust damper 42, or central damper 44 if the result of subtracting the starting temperature from the outside air temperature is less than a threshold. If the control unit 70 detects an abnormality or malfunction, it performs the same processing as in Example 1.

[0052] Figure 7 is a flowchart showing the equipment protection control procedure by the heat exchange ventilation system 100. As a prerequisite, the heat exchange ventilation system 100 is operating in heat exchange ventilation mode. The outside air sensor 60 performs sampling of the outside air temperature (S100). If the outside air temperature is -5°C or lower (Y in S102), the control unit 70 performs equipment protection control (S104) and then performs fault detection control (S106). On the other hand, if the outside air temperature is not -5°C or lower (N in S102), the control unit 70 releases the equipment protection control (S108).

[0053] Figure 8 is a flowchart showing the processing procedure by the heat exchange ventilation system 100. This corresponds to the equipment protection control in step S104 of Figure 7. The control unit 70 sets the operating air passage to a heat exchange ventilation system (S150). After a certain period of time has elapsed (Y in S152), the control unit 70 sets the operating air passage to internal circulation (S154). After a certain period of time has elapsed (Y in S156), the process returns to step S150. If no period of time has elapsed (N in S152, N in S156), the process returns to the flowchart in Figure 7.

[0054] Figure 9 is a flowchart showing the fault detection control procedure by the heat exchange ventilation system 100. This corresponds to the fault detection control in step S106 of Figure 7. If the operating airflow path has been changed from a heat exchanger to internal circulation (Y in S200), the control unit 70 acquires the outside air temperature as the starting temperature (S202). If the operating airflow path has not been changed from a heat exchanger to internal circulation (N in S200), the control unit 70 skips step S202. If the operating airflow path is not internal circulation (N in S204), the process returns to the flowchart in Figure 7. If the operating airflow path is internal circulation (Y in S204), after a predetermined time has elapsed, the control unit 70 acquires the outside air temperature (S206). If the difference between the outside air temperature and the starting temperature is not less than 5°C (N in S208), the control unit 70 determines that it is normal (S210) and returns to the flowchart in Figure 7.

[0055] If the difference between the ambient temperature and the starting temperature is less than 5°C (Y in S208), and a certain period of time has elapsed (Y in S212), the control unit 70 provisionally detects a fault and performs a retry determination (S214). If a retry has already been performed (Y in S216), the control unit 70 confirms the fault (S218). If a certain period of time has not elapsed (N in S212), or if a retry has not already been performed (N in S216), the process returns to the flowchart in Figure 7. Note that the number of retry determinations may be one or multiple times (for example, three times).

[0056] According to this embodiment, in internal circulation mode, an abnormality or malfunction in any of the outside air damper 40, exhaust damper 42, or central damper 44 is detected based on the starting temperature and the outside air temperature, so it is possible to determine whether internal air circulation is functioning correctly in internal circulation mode. Also, in internal circulation mode, if the result of subtracting the starting temperature from the outside air temperature is greater than a threshold, an abnormality or malfunction in any of the outside air damper 40, exhaust damper 42, or central damper 44 is detected, so it is possible to determine whether internal air circulation is functioning correctly in internal circulation mode. Furthermore, if an abnormality or malfunction is detected, the stepping motors of the outside air damper 40, exhaust damper 42, and central damper 44 are returned to their home positions, thereby resolving the abnormality or malfunction. Also, if an abnormality or malfunction is detected, the exhaust mode is executed, so the intake of outside air can be suppressed. Furthermore, since the intake of outside air is suppressed, the temperature drop can be suppressed. Furthermore, since the intake of outside air is suppressed, freezing of the heat exchange element 30, etc., can be suppressed. Furthermore, it notifies the user of any abnormalities or malfunctions when they are detected, thus informing the user of the occurrence of such problems.

[0057] An overview of one aspect of this disclosure is as follows: (Item 3) A housing (10) having an outside air inlet (12), an air intake inlet (14), a return air inlet (16), and an exhaust inlet (18), Within the housing (10), there is an outside air chamber (22) connected to the outside air port (12), Within the housing (10), there is an air supply chamber (24) connected to the air supply port (14), Within the housing (10), there is a return air chamber (26) connected to the return air port (16), Within the housing (10), there is an exhaust chamber (28) connected to the exhaust port (18), In the housing (10), a heat exchange element (30) performs heat exchange between an air supply passage (200) connecting the outside air chamber (22) and the air supply chamber (24), and an exhaust passage (202) connecting the return air chamber (26) and the exhaust chamber (28). An outside air damper (40) that can open and close the outside air vent (12), An exhaust damper (42) that can open and close the exhaust port (18), A central damper (44) is positioned between the outside air chamber (22) and the exhaust chamber (28), and is capable of opening and closing the space between the outside air chamber (22) and the exhaust chamber (28). A control unit (70) that controls the outside air damper (40), the exhaust damper (42), and the central damper (44), The system includes an outside air sensor (60) that measures the outside air temperature of the outside air chamber (22) and outputs the measured outside air temperature to the control unit (70), In the heat exchange mode, the control unit (70) opens the outside air damper (40) and the exhaust damper (42), and closes the central damper (44). The control unit (70), in the case of internal circulation mode, closes the outside air damper (40) and the exhaust damper (42), and opens the central damper (44). The control unit (70) is a heat exchange ventilation device (100) that, in the case of the internal circulation mode, detects an abnormality or malfunction in any of the outside air damper (40), the exhaust damper (42), or the central damper (44) based on the outside air temperature at a first timing and the outside air temperature at a second timing that is later than the first timing.

[0058] (Item 4) The control unit (70) detects an abnormality or malfunction in any of the outside air damper (40), the exhaust damper (42), or the central damper (44) in the case of internal circulation mode, according to item 3, when the result of subtracting the outside air temperature at the first timing from the outside air temperature at the second timing is less than a threshold.

[0059] (Item 5) Each of the aforementioned outside air damper (40), exhaust damper (42), and central damper (44) has a stepping motor. The heat exchange ventilation device (100) described in item 3 or 4, wherein the control unit (70) causes the stepping motor to return to its home position when it detects an abnormality or malfunction in any of the outside air damper (40), the exhaust damper (42), or the central damper (44).

[0060] (Item 6) The heat exchange ventilation system (100) according to item 3 or 4, wherein the control unit (70) detects an abnormality or malfunction in any of the outside air damper (40), the exhaust damper (42), or the central damper (44), and executes an exhaust mode by closing the outside air damper (40) and the central damper (44) and opening the exhaust damper (42).

[0061] (Item 7) The heat exchange ventilation system (100) according to item 3 or 4, further comprising a notification unit that notifies of an abnormality or malfunction when the control unit (70) detects an abnormality or malfunction in any of the outside air damper (40), the exhaust damper (42), or the central damper (44).

[0062] The present disclosure has been described above based on the embodiments, but the present disclosure is not limited in any way to the embodiments described above, and it can be easily inferred that various improvements and modifications are possible without departing from the spirit of the present disclosure. For example, in this embodiment, an outside air port 12 and an exhaust port 18 are arranged on the first side surface of the housing 10, and an air intake port 14 and a return air port 16 are arranged on the second side surface, but the outside air port 12, exhaust port 18, air intake port 14 and return air port 16 may be arranged on the first side surface. [Explanation of Symbols]

[0063] 10 Enclosure, 12 Outside air vent, 14 Intake air vent, 16 Return air vent, 18 Exhaust vent, 22 Outside air chamber, 24 Intake air chamber, 26 Return air chamber, 28 Exhaust chamber, 30 Heat exchange element, 40 Outside air damper, 42 Exhaust damper, 44 Central damper, 50 Intake fan, 52 Exhaust fan, 60 Outside air sensor, 62 Return air sensor, 70 Control unit, 100 Heat exchange ventilation system, 200 Intake air passage, 202 Exhaust air passage.

Claims

1. A housing having an outside air inlet, an air intake inlet, a return air inlet, and an exhaust inlet, Within the housing, there is an outside air chamber connected to the outside air port, Within the housing, there is an air intake chamber connected to the air intake port, Within the housing, there is a return air chamber connected to the return air port, Within the housing, there is an exhaust chamber connected to the exhaust port, In the housing, a heat exchange element is provided that performs heat exchange between an air supply passage connecting the outside air chamber and the air supply chamber and an exhaust passage connecting the return air chamber and the exhaust chamber. An outside air damper that can open and close the aforementioned outside air vent, An exhaust damper that can open and close the aforementioned exhaust port, A central damper is positioned between the outside air chamber and the exhaust chamber, and is capable of opening and closing the space between the outside air chamber and the exhaust chamber. A control unit that controls the outside air damper, the exhaust damper, and the central damper, An outside air sensor measures the outside air temperature of the outside air chamber and outputs the measured outside air temperature to the control unit, The system includes a return air sensor that measures the return air temperature in the return air chamber and outputs the measured return air temperature to the control unit, In the heat exchange mode, the control unit opens the outside air damper and the exhaust damper, and closes the central damper. In the case of internal circulation mode, the control unit closes the outside air damper and the exhaust damper, and opens the central damper. The control unit, in the case of the internal circulation mode, detects an abnormality or malfunction in any of the outside air damper, the exhaust damper, or the central damper based on the outside air temperature and the return air temperature of the heat exchange ventilation system.

2. The heat exchange ventilation system according to claim 1, wherein the control unit detects an abnormality or malfunction in any of the outside air damper, the exhaust damper, or the central damper when the result of subtracting the outside air temperature from the return air temperature is greater than a threshold value in the internal circulation mode.

3. A housing having an outside air inlet, an air intake inlet, a return air inlet, and an exhaust inlet, Within the housing, there is an outside air chamber connected to the outside air port, Within the housing, there is an air intake chamber connected to the air intake port, Within the housing, there is a return air chamber connected to the return air port, Within the housing, there is an exhaust chamber connected to the exhaust port, In the housing, a heat exchange element is provided that performs heat exchange between an air supply passage connecting the outside air chamber and the air supply chamber and an exhaust passage connecting the return air chamber and the exhaust chamber. An outside air damper that can open and close the aforementioned outside air vent, An exhaust damper that can open and close the aforementioned exhaust port, A central damper is positioned between the outside air chamber and the exhaust chamber, and is capable of opening and closing the space between the outside air chamber and the exhaust chamber. A control unit that controls the outside air damper, the exhaust damper, and the central damper, The system includes an outside air sensor that measures the outside air temperature of the outside air chamber and outputs the measured outside air temperature to the control unit, In the heat exchange mode, the control unit opens the outside air damper and the exhaust damper, and closes the central damper. In the case of internal circulation mode, the control unit closes the outside air damper and the exhaust damper, and opens the central damper. The control unit, in the case of the internal circulation mode, detects an abnormality or malfunction in any of the outside air damper, the exhaust damper, or the central damper based on the outside air temperature at a first timing and the outside air temperature at a second timing that is later than the first timing in the heat exchange ventilation system.

4. The heat exchange ventilation system according to claim 3, wherein the control unit detects an abnormality or malfunction in any of the outside air damper, the exhaust damper, or the central damper when the result of subtracting the outside air temperature at the first timing from the outside air temperature at the second timing is less than a threshold value in the internal circulation mode.

5. Each of the aforementioned outside air damper, exhaust damper, and central damper has a stepping motor. The heat exchange ventilation device according to any one of claims 1 to 4, wherein the control unit causes the stepping motor to return to its home position when it detects an abnormality or malfunction in any of the outside air damper, the exhaust damper, or the central damper.

6. The heat exchange ventilation system according to any one of claims 1 to 4, wherein the control unit, when it detects an abnormality or malfunction in any of the outside air damper, the exhaust damper, or the central damper, closes the outside air damper and the central damper and opens the exhaust damper to execute the exhaust mode.

7. The heat exchange ventilation system according to any one of claims 1 to 4, further comprising a notification unit that notifies of an abnormality or malfunction when the control unit detects an abnormality or malfunction in any of the outside air damper, the exhaust damper, or the central damper.

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