WO2022085177A1 - Ventilation device - Google Patents

Abstract

This ventilation device comprises: a casing that includes, formed therein, an air supply channel through which air blown from an air supply port passes and an exhaust channel through which air blown from an exhaust port passes; a total heat exchanger that is disposed in the casing and exchanges heat between the air flowing through the air supply channel and the air flowing through the exhaust channel; a first temperature sensor that detects the air temperature on the inlet side of the air supply channel; a second temperature sensor that detects the air temperature on the outlet side of the air supply channel; a third temperature sensor that detects the air temperature on the inlet side of the exhaust channel; and a controller that determines that an abnormality has occurred if the temperature efficiency of the total heat exchanger calculated on the basis of the respective air temperatures detected by the first, second, and third temperature sensors is greater than a reference value.

Description

Ventilation system

This disclosure relates to a ventilation system equipped with a total heat exchanger.

Conventionally, there is a ventilation device that prevents dew condensation on the total heat exchanger (see, for example, Patent Document 1).

Patent Document 1 describes an air supply fan provided with an air supply motor, an exhaust fan provided with an exhaust motor, and a total heat exchanger for exchanging heat when ventilating indoor air and outdoor air. A temperature detecting means provided on the air supply inlet side of the heat exchange element in the air supply / ventilation path and a humidity detecting means provided on the exhaust inlet side of the heat exchange element in the exhaust air blowing path. The rotation speed of the air supply motor and the exhaust motor is reduced according to the temperature detected by the air supply and the humidity detected by the humidity detection means, and the air supply air volume and the exhaust air volume are reduced to exhaust the total heat exchanger. It prevents dew condensation that occurs at the side outlet. Further, in Patent Document 1, filters for air purification are provided on the outdoor air suction side and the indoor air suction side of the total heat exchanger, respectively.

Japanese Unexamined Patent Publication No. 2016-65692

Patent Document 1 can prevent dew condensation on the total heat exchanger, but detects that an abnormality has occurred due to an abnormality due to dew condensation or freezing, or an abnormality due to a decrease in air volume caused by clogging of a filter or the like. There was a problem that it could not be done.

The present disclosure has been made to solve the above problems, and when an abnormality due to dew condensation or freezing or an abnormality due to a decrease in air volume caused by filter clogging occurs, it is necessary to detect the occurrence of such abnormality. The purpose is to provide a ventilation system that can be used.

The ventilation device according to the present disclosure is arranged in the casing and the casing in which the air supply passage through which the air blown from the air supply port passes and the exhaust passage through which the air blown out from the exhaust port passes are formed. A total heat exchanger that exchanges heat between the air flowing through the air supply passage and the air flowing through the exhaust passage, a first temperature sensor that detects the air temperature on the inlet side of the air supply passage, and an outlet side of the air supply passage. The second temperature sensor that detects the air temperature, the third temperature sensor that detects the air temperature on the inlet side of the exhaust passage, the first temperature sensor, the second temperature sensor, and the third temperature sensor It is provided with a control device for determining that an abnormality has occurred when the temperature efficiency of the total heat exchanger calculated based on each detected air temperature is larger than the reference value.

All calculated based on each air temperature detected by the first temperature sensor, the second temperature sensor, and the third temperature sensor when an abnormality occurs due to an abnormality due to dew condensation or freezing, or an abnormality due to a decrease in air volume caused by clogging of the filter. The temperature efficiency of the heat exchanger becomes larger than the standard value. Therefore, according to the ventilation device according to the present disclosure, when the above temperature efficiency is larger than the reference value, it is determined that an abnormality has occurred, and the air volume is reduced due to an abnormality due to dew condensation or freezing, or a filter clogging. When an abnormality occurs, it is possible to detect that the abnormality has occurred.

It is a top view which shows the structure of the ventilation apparatus which concerns on Embodiment 1. FIG. It is a side schematic diagram which shows the structure of the ventilation apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the temperature change of the supply air and the exhaust when the outside air temperature is higher than the room temperature in the normal state of the total heat exchanger which concerns on Embodiment 1. FIG. It is a figure which shows the temperature change of the supply air and the exhaust when the outside air temperature is lower than the room temperature in the normal state of the total heat exchanger which concerns on Embodiment 1. FIG. It is a figure which shows the temperature change of the supply air and the exhaust when the outside air temperature is higher than the room temperature in the state of dew condensation, freezing, or a decrease in air volume in the total heat exchanger according to the first embodiment. It is a figure which shows the temperature change of the air supply and the exhaust when the outside air temperature is lower than the room temperature in the state of dew condensation, freezing, or a decrease in air volume in the total heat exchanger according to the first embodiment. It is a figure which shows the change of the temperature efficiency of the total heat exchanger at the time of the occurrence of dew condensation or freezing which concerns on Embodiment 1. FIG. It is a figure which shows the change of the temperature efficiency of the total heat exchanger when the air volume drop occurs which concerns on Embodiment 1. FIG. It is a figure which shows the control flow which identifies the abnormality factor of the ventilation apparatus which concerns on Embodiment 1. FIG. It is a refrigerant circuit diagram of the ventilation system which concerns on Embodiment 2. FIG. It is a side schematic diagram which shows the structure of the ventilation apparatus which concerns on Embodiment 2. FIG. It is a figure which shows the control flow which identifies the abnormal factor of the ventilation apparatus which concerns on Embodiment 2. It is a side schematic diagram which shows the structure of the modification of the ventilation apparatus which concerns on Embodiment 2. FIG.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the embodiments described below. Further, in the drawings below, the relationship between the sizes of the constituent members may differ from the actual one.

Embodiment 1.
FIG. 1 is a schematic top view showing the configuration of the ventilation device 1 according to the first embodiment. FIG. 2 is a schematic side view showing the configuration of the ventilation device 1 according to the first embodiment.

As shown in FIGS. 1 and 2, the ventilation device 1 according to the first embodiment includes a casing 10, an air supply fan 11, an air supply fan motor 12, an exhaust fan 13, and an exhaust fan motor 14. It includes a heat exchanger 20, an air supply filter 41, and an exhaust filter 42. Further, the ventilation device 1 includes an outside air temperature sensor (hereinafter, also referred to as a first temperature sensor) 51, a supply air temperature sensor (hereinafter, also referred to as a second temperature sensor) 52, and an indoor air temperature sensor (hereinafter, a third temperature). It includes a 53 (also referred to as a sensor), an exhaust temperature sensor 54, and a control device 30.

The casing 10 constitutes the outer shell of the ventilation device 1, and has an outside air port 10a for taking in outside air (OA) inside, an exhaust port 10b for discharging exhaust gas (EA) to the outside, and a return air (RA) inside. It is provided with a return air port 10c for taking in air and an air supply port 10d for supplying air supply (SA) into the room. Further, inside the casing 10, an air supply passage 10ad through which air taken in from the outside air port 10a and blown out from the air supply port 10d passes, and air taken in from the return air port 10c and blown out from the exhaust port 10b. The exhaust passage 10bc through which the air passes is formed. In the following, the return air is also referred to as indoor air.

The total heat exchanger 20 is made of paper, for example, and exchanges sensible heat and latent heat between the air flowing through the air supply passage 10ad and the air flowing through the exhaust passage 10bc, that is, exchanging the total heat.

The air supply filter 41 and the exhaust filter 42 are provided on the total heat exchanger 20, respectively, and remove dust or dirt from the total heat exchanger 20 so as not to adhere to the total heat exchanger 20. The air supply filter 41 is provided at a position on the windward side of the air supply passage 10ad in the total heat exchanger 20, and the exhaust filter 42 is provided at a position on the windward side of the exhaust passage 10bc in the total heat exchanger 20. Has been done.

The supply air fan motor 12 operates the supply air fan 11, and the exhaust fan motor 14 operates the exhaust fan 13. The supply air fan motor 12 and the exhaust fan motor 14 may be controlled by fixing the rotation speed, or may be controlled by changing the rotation speed step by step.

The air supply fan 11 takes in the outside air (OA) from the outside air port 10a into the air supply passage 10ad in the casing 10, exchanges the total heat with the total heat exchanger 20, and then supplies air (SA) from the air supply port 10d. It is supplied to the room, which is the space subject to air conditioning. The exhaust fan 13 takes in the return air (RA) from the return air port 10c into the exhaust passage 10bc in the casing 10, exchanges the total heat with the total heat exchanger 20, and then exhausts (EA) from the exhaust port 10b to the outside. It is to be discharged to.

The outside air temperature sensor 51 is provided, for example, in the vicinity of the outside air port 10a of the casing 10 and detects the air temperature on the inlet side of the supply air passage 10ad, that is, the outside air temperature. The supply air temperature sensor 52 is provided, for example, in the vicinity of the air supply port 10d of the casing 10 and detects the air temperature on the outlet side of the supply air passage 10ad, that is, the supply air temperature. The indoor air temperature sensor 53 is provided, for example, in the vicinity of the return air port 10c of the casing 10 and detects the air temperature on the inlet side of the exhaust passage 10bc, that is, the indoor temperature. The exhaust temperature sensor 54 is provided, for example, in the vicinity of the exhaust port 10b of the casing 10 and detects the air temperature on the outlet side of the exhaust passage 10bc, that is, the exhaust temperature. Each of these temperature sensors is composed of, for example, a thermistor.

The control device 30 has a microcomputer equipped with a CPU, ROM, RAM, I / O port, and the like. The control device 30 controls the operation of the entire ventilation device 1 including the supply air fan motor 12 and the exhaust fan motor 14 based on the detection signal from each temperature sensor, the operation signal from the operation unit (not shown), and the like. The control device 30 may be provided in the ventilation device 1, or may be provided separately from the ventilation device 1 and may be configured to control the ventilation device 1 by communication.

Further, the control device 30 has a storage unit 31, an extraction unit 32, a calculation unit 33, and a comparison unit as functional blocks related to abnormality detection of the ventilation device 1, control of the air supply fan 11 and the exhaust fan 13, and identification of the abnormal location. It includes 34, a determination unit 35, a control unit 36, and a notification unit 37.

The storage unit 31 is configured to store data related to the temperature detected by each temperature sensor. These data are periodically acquired during the operation of the ventilator 1. Further, various data necessary for abnormality determination are stored in the storage unit 31.

The extraction unit 32 is configured to extract data necessary for abnormality determination from the data stored in the storage unit 31.

The calculation unit 33 is configured to perform necessary calculations based on the data extracted by the extraction unit 32.

The comparison unit 34 is configured to compare the value obtained by the calculation in the calculation unit 33 with the threshold value, or to compare the values obtained by the calculation in the calculation unit 33.

The determination unit 35 is configured to perform abnormality determination on the ventilation device 1 based on the comparison result in the comparison unit 34.

The control unit 36 controls the supply air fan 11 and the exhaust fan 13 according to each operation mode such as a dry operation and a normal ventilation operation based on the result of the determination unit 35.

The notification unit 37 displays a part that displays the operation mode controlled by the control unit 36, and an abnormality such as an abnormality due to dew condensation or freezing or an abnormality due to a decrease in air volume caused by filter clogging based on the result of the determination unit 35. It is composed of the part to be used and the part to be used.

The notification unit 37 may be provided in the control device 30, or may be provided separately from the control device 30, and may be configured by, for example, a remote PC. When it is separate from the control device 30, the notification unit 37 is configured to notify the operation mode of the ventilation device 1 and the content of an abnormality by a command from the control device 30. The notification unit 37 has at least one of a display unit for visually notifying information and a voice output unit for aurally notifying information.

Next, the temperature changes of the air supply and the exhaust of the ventilation device 1 will be described with reference to FIGS. 3 and 4.

FIG. 3 is a diagram showing temperature changes of air supply and exhaust when the outside air temperature _TOA in the normal state of the total heat exchanger 20 according to the first embodiment is higher than the room temperature _TRA .

As can be seen from FIG. 3, high-temperature outside air is supplied from the supply air passage 11ad and low-temperature indoor air is supplied from the exhaust passage 11bc to the total heat exchanger 20, and the total heat is exchanged between the outside air and the indoor air. .. After that, the outside air is supplied to the room as supply air whose temperature has dropped, and the indoor air is discharged to the outside as exhaust gas whose temperature has risen.

Here, as an index indicating the performance of the total heat exchanger 20, the normal temperature efficiency _ηc when the outside air temperature _TOA is higher than the room temperature _TRA ( _TOA > TRA) is as follows.

FIG. 4 is a diagram showing temperature changes of air supply and exhaust when the outside air temperature _TOA in the normal state of the total heat exchanger 20 according to the first embodiment is lower than the room temperature _TRA .

As can be seen from FIG. 4, low-temperature outside air is supplied from the supply air passage 11ad and high-temperature indoor air is supplied from the exhaust passage 11bc to the total heat exchanger 20, and the total heat is exchanged between the outside air and the indoor air. .. After that, the outside air is supplied to the room as supply air whose temperature has risen, and the indoor air is discharged to the outside as exhaust gas whose temperature has dropped.

Here, as an index showing the performance of the total heat exchanger 20, the normal temperature efficiency _ηh when the outside air temperature TOA is lower than the room temperature _TRA ( _TOA < _TRA ) is as follows.

[Abnormal ventilation system]
Next, the abnormality of the ventilation device 1 according to the first embodiment will be described.

The abnormalities of the ventilation device 1 include abnormalities due to dew condensation or freezing and abnormalities due to a decrease in air volume caused by clogging of the filter, and these abnormalities will be described in detail.

First, we will explain about dew condensation and freezing. Condensation occurs when the air on the higher temperature side is cooled in the outside air and the indoor air where the total heat is exchanged by the total heat exchanger 20, the temperature drops to the dew point temperature, and the moisture in the air is deposited on the surface of the total heat exchanger 20. Is. Then, the freezing is that the moisture in the air condenses in the total heat exchanger 20 and then freezes, and the ice block grows until the air passage is blocked. When this dew or ice occurs, water droplets fall from the inside of the ventilation device 1, that is, dew drips, which causes complaints, and mold or fungi grow on the surface of the total heat exchanger 20, which is not possible. It will be in a hygienic condition. In addition, this dew condensation is also a factor that causes deterioration of the total heat exchanger 20.

When dew condensation or freezing occurs, the total heat exchanger 20 gets wet as described above. Normally, the thermal conductivity of the total heat exchanger 20 is about 0.06 [W / (mk)], which is the thermal conductivity of paper, which is a main component thereof. However, when the total heat exchanger 20 gets wet, its thermal conductivity becomes close to the thermal conductivity of water of 0.6 [W / (mk)], so that the temperature efficiency is improved, that is, the value of the temperature efficiency η is increased. It gets higher.

Next, the decrease in air volume will be explained. The decrease in air volume caused by clogging of the filter or the like is caused by the accumulation of dust or dirt in the air supply filter 41 and the exhaust filter 42. When the air volume drops, the required ventilation volume cannot be supplied to the room. Therefore, in the past, the filter was cleaned regularly to ensure the required ventilation volume. However, at present, the filter is cleaned after a certain period of time, and there is no one that detects a decrease in air volume in the state of the filter.

When the air volume on the high temperature side decreases due to clogging of the filter or the like, the air volume on the relatively low temperature side increases, so that the high temperature air easily exchanges heat with the low temperature air in the total heat exchanger 20. The high temperature air approaches the low temperature air. Therefore, the temperature efficiency of the total heat exchanger 20 is improved, that is, the value of the temperature efficiency η is increased.

FIGS. 5 and 6 will be used to explain changes in the temperature of the supply air and the exhaust gas of the ventilation device 1 when dew condensation, freezing, or a decrease in air volume occurs.

FIG. 5 is a diagram showing temperature changes of air supply and exhaust when the outside air temperature _TOA is higher than the room temperature _TRA when the total heat exchanger 20 according to the first embodiment is in a state of dew condensation, freezing, or a decrease in air volume. be.

As can be seen from FIG. 5, high temperature outside air is supplied from the supply air passage 11ad and low temperature indoor air is supplied from the exhaust passage 11bc to the total heat exchanger 20, and total heat exchange is performed between the outside air and the indoor air. .. After that, the outside air is supplied to the room as supply air whose temperature has dropped, and the indoor air is discharged to the outside as exhaust gas whose temperature has risen. However, the heat exchange performance of the total heat exchanger 20 is improved due to dew condensation, freezing, or a decrease in air volume. do. Therefore, it can be seen that the supply air temperature _{T'SA in the abnormal state (thick dotted line) is lower than the supply air temperature T SA in} the normal state (thin dotted line).

Here, as an index indicating the performance of the total heat exchanger 20, the temperature efficiency _ηc'at the time of abnormality when the outside air temperature TOA is higher than the room temperature _TRA ( _TOA > _TRA ) is as follows.

FIG. 6 shows supply and exhaust when the total heat exchanger 20 according to the first embodiment has an outside air temperature _TOA lower than the room temperature _TRA ( _TOA < _TRA ) when the total heat exchanger 20 is in a state of dew condensation, freezing, or a decrease in air volume. It is a figure which shows the temperature change of.

As can be seen from FIG. 6, low-temperature outside air is supplied from the supply air passage 11ad and high-temperature indoor air is supplied from the exhaust passage 11bc to the total heat exchanger 20, and the total heat is exchanged between the outside air and the indoor air. .. After that, the outside air is supplied to the room as supply air whose temperature has risen, and the indoor air is discharged to the outside as exhaust gas whose temperature has dropped. However, the heat exchange performance of the total heat exchanger 20 is improved due to dew condensation, freezing, or a decrease in air volume. do. Therefore, it can be seen that the supply air temperature _{T'SA in the abnormal state (thick dotted line) is higher than the supply air temperature T SA in} the normal state (thin dotted line).

Here, as an index indicating the performance of the total heat exchanger 20, the temperature efficiency _ηh'at the time of abnormality when the outside air temperature TOA is lower than the room temperature _TRA ( _TOA < _TRA ) is as follows.

[About the abnormality detection method of the ventilation system]
As described above, it can be seen that there is a difference in the value of the temperature efficiency η between the normal state and the abnormal time, and the value of the temperature efficiency η is higher in the state of dew condensation, freezing, or the decrease in air volume than in the normal state. Therefore, using the value of this temperature efficiency η, first, whether it is a normal state or an abnormal state is specified.

In addition, when the temperature efficiency η suspected of dew condensation or freezing becomes larger than the preset standard value ηst, the total heat of dew condensation or freezing is to be suppressed in order to suppress the generation of dew dripping, mold, and bacteria. It is desirable to dry the exchanger 20. Therefore, in that case, a drying operation for drying the total heat exchanger 20 is performed. Here, the drying operation is an operation in which either one of the air supply fan 11 and the exhaust fan 13 is stopped to dry the total heat exchanger 20. On the other hand, the normal operation is an operation in which both the air supply fan 11 and the exhaust fan 13 are operated.

Using this drying operation, it is possible to identify the cause of the abnormality, whether it is an abnormality due to dew condensation or freezing, or an abnormality due to a decrease in air volume caused by clogging of the filter.

To identify the cause of the abnormality, whether it is an abnormality due to dew condensation or freezing or an abnormality due to a decrease in air volume, the change in the temperature efficiency η when the total heat exchanger 20 is dried in the drying operation and the temperature efficiency after returning to the normal operation after the drying operation. It is done from at least one of the changes in η.

Using FIGS. 7 and 8, the difference between the abnormality due to dew condensation or freezing and the abnormality due to the decrease in air volume will be described.

FIG. 7 is a diagram showing changes in the temperature efficiency η of the total heat exchanger 20 when dew condensation or freezing occurs according to the first embodiment. FIG. 8 is a diagram showing changes in the temperature efficiency η of the total heat exchanger 20 when a decrease in air volume occurs according to the first embodiment. In addition, in FIG. 7 and FIG. 8, both were determined to be abnormal at t1 during normal operation, then the dry operation was performed from t1 to t3, and after t3, the time (horizontal axis) when the normal operation was performed. It shows the change in temperature efficiency η (vertical axis). Further, η1 in FIGS. 7 and 8 is the temperature efficiency when the ventilation device 1 is normal. Further, η2 in FIGS. 7 and 8 is the temperature efficiency used when determining whether or not an abnormality has occurred in the ventilation device 1. Further, η3 in FIGS. 7 and 8 is used to determine which of the abnormalities caused by dew condensation or freezing and the abnormalities caused by the air volume decrease caused by the clogging of the filter, etc., when the ventilation device 1 is abnormal. Temperature efficiency.

First, the difference between the time when dew condensation or ice formation occurs and the time when the air volume decreases when the total heat exchanger 20 is dried in the drying operation will be described.

When dew or freezing occurs, as shown in FIG. 7, the heat capacity of water, the latent heat of evaporation, and the temperature decrease, so that the temperature efficiency is η = 0 (= η3), that is, the air entering the total heat exchanger 20 and all. It takes time from t1 to t3 until the temperature difference from the air discharged from the heat exchanger 20 becomes zero. On the other hand, when the air volume drops, as shown in FIG. 8, when one of the supply air fan 11 and the exhaust fan 13 is stopped due to the dry operation, t1 to 0 (= η3) until η = 0 (= η3). It only takes t2 time. That is, since there is no temperature change in the total heat exchanger 20 when the air volume drops, η = 0 in a short time of t1 to t2, but when dew condensation or freezing occurs, the temperature in the total heat exchanger 20 Since there is a change, it takes time for the temperature efficiency η = 0. Therefore, depending on the time it takes for the temperature efficiency to change from η2 to η3, it is possible to know which of dew condensation, freezing, and air volume reduction has occurred.

Next, the difference between the time when dew condensation or freezing occurs and the time when the air volume drops occurs during normal operation after the total heat exchanger 20 is dried in the drying operation will be described.

When dew condensation or freezing occurs, as shown in FIG. 7, when the total heat exchanger 20 gradually gets wet due to dew condensation or freezing, the heat capacity of water, the latent heat of vaporization, and the temperature do not easily rise, so that the temperature efficiency η It takes some time for the value of to rise to η2 (see t3 to t5). On the other hand, when the air volume drops, as shown in FIG. 8, the temperature efficiency η increases to η2 in a short time because the state of the total heat exchanger 20 does not change as in the case of dew condensation or icing. See t5). Therefore, depending on the time it takes for the temperature efficiency to change from η3 to η2, it is possible to know which of dew condensation, freezing, and air volume reduction has occurred.

A control flow for identifying an abnormal factor of the ventilation device 1 according to the first embodiment will be described with reference to FIG. 9.

FIG. 9 is a diagram showing a control flow for identifying an abnormal factor of the ventilation device 1 according to the first embodiment. It is assumed that normal operation is performed at the start of the control flow shown in FIG.

(Step S101)
The control device 30 calculates the current temperature efficiency ηnow based on each air temperature detected by the outside air temperature sensor 51, the supply air temperature sensor 52, and the indoor air temperature sensor 53.

(Step S102)
The control device 30 determines whether or not the difference between the current temperature efficiency ηnow and the reference value ηst is larger than 0. When the control device 30 determines that the difference between the current temperature efficiency ηnow and the reference value ηst is larger than 0, it is determined that the difference is greater than 0, and the process proceeds to step S103. On the other hand, when the control device 30 determines that the difference between the current temperature efficiency ηnow and the reference value ηst is 0 or less, it determines that it is normal and ends this control flow.

(Step S103)
The control device 30 stops the exhaust fan 13 and starts the drying operation. Further, the control device 30 notifies the notification unit 37 that the drying operation is being performed. Although an example of stopping the exhaust fan 13 in order to start the drying operation has been described here, the supply air fan 11 may be stopped.

(Step S104)
The control device 30 determines whether or not a certain time has elapsed after starting the drying operation. When the control device 30 determines that a certain time has elapsed after starting the drying operation, the total heat exchanger 20 is determined to be dry, and the process proceeds to step S105. On the other hand, when the control device 30 determines that a certain time has not elapsed since the start of the drying operation, it is determined that the total heat exchanger 20 is not dry, and the process of step S104 is performed again.

Here, in the process of step S104, the control device 30 determines that the total heat exchanger 20 has dried after a certain period of time has elapsed after the start of the drying operation, but the present invention is not limited thereto. For example, the control device 30 may determine that the total heat exchanger 20 is dry when the difference between the supply air temperature T _SA and the outside air temperature _TO A becomes 0 and the temperature efficiency η = 0.

(Step S105)
The control device 30 operates the exhaust fan 13 and starts normal operation. Further, the control device 30 notifies the notification unit 37 that the normal operation is being performed.

(Step S106)
The control device 30 calculates the current temperature efficiency ηnow based on each air temperature detected by the outside air temperature sensor 51, the supply air temperature sensor 52, and the indoor air temperature sensor 53.

(Step S107)
The control device 30 determines whether or not the difference between the current temperature efficiency ηnow and the reference value ηst is larger than 0. When the control device 30 determines that the difference between the current temperature efficiency ηnow and the reference value ηst is larger than 0, it is determined that the abnormality is due to the decrease in air volume, and the process proceeds to step S108. On the other hand, when the control device 30 determines that the difference between the current temperature efficiency ηnow and the reference value ηst is 0 or less, it is determined that there is no abnormality due to the decrease in air volume, and this control flow is terminated. Before ending the control flow, the control device 30 may notify the notification unit 37 that the abnormality is due to dew condensation or freezing.

(Step S108)
The control device 30 notifies the notification unit 37 that the abnormality is caused by the decrease in air volume.

As described above, the ventilation device 1 according to the first embodiment is a casing 10 in which an air supply passage 10ad through which the air blown from the air supply port 10d passes and an exhaust passage 10bc through which the air blown from the exhaust port 10b passes are formed. A total heat exchanger 20 that is arranged in the casing 10 and exchanges heat between the air flowing through the air supply passage 10ad and the air flowing through the exhaust passage 10bc, and the first that detects the air temperature on the inlet side of the air supply passage 10ad. The temperature sensor 51, the second temperature sensor 52 that detects the air temperature on the outlet side of the air supply passage 10ad, the third temperature sensor 53 that detects the air temperature on the inlet side of the exhaust passage 10bc, and the first temperature sensor 51. Control to determine that an abnormality has occurred when the temperature efficiency of the total heat exchanger 20 calculated based on each air temperature detected by the second temperature sensor 52 and the third temperature sensor 53 is larger than the reference value. The device 30 is provided.

When an abnormality occurs due to an abnormality due to dew condensation or freezing, or an abnormality due to a decrease in air volume caused by clogging of the filter, etc., it is calculated based on each air temperature detected by the first temperature sensor 51, the second temperature sensor 52, and the third temperature sensor 53. The temperature efficiency of the total heat exchanger 20 becomes larger than the reference value. Therefore, according to the ventilation device 1 according to the first embodiment, when the above temperature efficiency is larger than the reference value, it is determined that an abnormality has occurred. By doing so, when an abnormality due to dew condensation or freezing or an abnormality due to a decrease in air volume caused by clogging of the filter or the like occurs, it is possible to detect that the abnormality has occurred.

Further, the ventilation device 1 according to the first embodiment includes an air supply fan 11 for flowing air through the supply air passage 10ad and an exhaust fan 13 for flowing air through the exhaust passage 10bc, and the control device 30 is an air supply fan. If it is determined that an abnormality has occurred during normal operation in which both the air supply fan 11 and the exhaust fan 13 are operated, a drying operation is performed in which one of the air supply fan 11 and the exhaust fan 13 is stopped.

According to the ventilation device 1 according to the first embodiment, if it is determined that an abnormality has occurred during normal operation, a drying operation is performed in which either the supply air fan 11 or the exhaust fan 13 is stopped. Therefore, even if an abnormality occurs in the ventilation device 1 due to dew condensation or freezing, the total heat exchanger 20 can be dried.

Further, in the ventilation device 1 according to the first embodiment, the control device 30 is detected by the first temperature sensor 51, the second temperature sensor 52, and the third temperature sensor 53 after a certain period of time has elapsed from the start of the drying operation. If the temperature efficiency calculated based on each air temperature is greater than the reference value, it is determined that an abnormality has occurred due to a decrease in air volume, and if the temperature efficiency is below the reference value, an abnormality due to dew condensation or freezing has occurred. It is determined that it has occurred.

According to the ventilation device 1 according to the first embodiment, if the temperature efficiency calculated after a certain period of time has elapsed from the start of the drying operation is larger than the reference value, it is determined that an abnormality due to a decrease in air volume has occurred, and the temperature efficiency is determined. If is less than or equal to the reference value, it is determined that an abnormality due to dew condensation or freezing has occurred. Therefore, it is possible to identify the cause of the abnormality, which of the abnormalities caused by dew condensation or freezing and the abnormalities caused by the decrease in air volume caused by the clogging of the filter.

Further, the ventilation device 1 according to the first embodiment includes a notification unit 37, and the control device 30 notifies the notification unit 37 that the drying operation is being performed during the drying operation.

According to the ventilation device 1 according to the first embodiment, the notification unit 37 notifies the user that the drying operation is being performed during the drying operation, so that the user can be notified that the ventilation device 1 is in the drying operation. can.

Further, in the ventilation device 1 according to the first embodiment, when the control device 30 determines that an abnormality due to dew condensation or freezing has occurred, the notification unit 37 notifies that fact, and an abnormality occurs due to a decrease in air volume. If it is determined that the problem is observed, the notification unit 37 notifies the user to that effect.

According to the ventilation device 1 according to the first embodiment, the notification unit 37 notifies the user of the abnormal factor when an abnormality due to dew condensation or freezing or an abnormality due to a decrease in air volume occurs, so that the user is notified of the abnormal factor of the ventilation device 1. I can inform you.

Embodiment 2.
Hereinafter, the second embodiment will be described, but the description thereof will be omitted for those overlapping with the first embodiment, and the same parts or the corresponding parts as those in the first embodiment will be designated by the same reference numerals.

FIG. 10 is a refrigerant circuit diagram of the ventilation device 1 according to the second embodiment. FIG. 11 is a schematic side view showing the configuration of the ventilation device 1 according to the second embodiment.

In the ventilation device 1 according to the second embodiment, as shown in FIG. 10, the compressor 111, the flow path switching device 112, the first heat exchanger 113, the throttle device 121, and the second heat exchanger 122 are sequentially connected by piping. It is provided with a refrigerant circuit 101 through which the refrigerant circulates. The ventilation device 1 can operate both the cooling operation and the heating operation by switching the flow path switching device 112. Further, the refrigerant circuit 101 is provided with a suction pressure sensor 116 and a condensation temperature sensor 153.

The compressor 111 sucks in the low temperature and low pressure refrigerant, compresses the sucked refrigerant, and discharges the high temperature and high pressure refrigerant. The compressor 111 is composed of, for example, an inverter compressor whose capacity, which is a transmission amount per unit time, is controlled by changing the operating frequency.

The flow path switching device 112 is, for example, a four-way valve, and switches between cooling operation and heating operation by switching the flow direction of the refrigerant. The flow path switching device 112 switches to the state shown by the solid line in FIG. 10 during the cooling operation, and the discharge side of the compressor 111 and the first heat exchanger 113 are connected to each other. Further, the flow path switching device 112 switches to the state shown by the broken line in FIG. 10 during the heating operation, and the discharge side of the compressor 111 and the second heat exchanger 122 are connected to each other.

The first heat exchanger 113 exchanges heat between the outside air and the refrigerant. The first heat exchanger 113 functions as a condenser that dissipates the heat of the refrigerant to the outside air and condenses the refrigerant during the cooling operation. Further, the first heat exchanger 113 functions as an evaporator that evaporates the refrigerant during the heating operation and cools the outside air by the heat of vaporization at that time.

The throttle device 121 is, for example, an electronic expansion valve capable of adjusting the opening degree of the throttle, and by adjusting the opening degree, the pressure of the refrigerant flowing into the first heat exchanger 113 or the second heat exchanger 122 can be adjusted. Control.

The second heat exchanger 122 exchanges heat between the indoor air and the refrigerant. The second heat exchanger 122 functions as an evaporator that evaporates the refrigerant during the cooling operation and cools the indoor air by the heat of vaporization at that time. Further, the second heat exchanger 122 functions as a condenser that dissipates the heat of the refrigerant to the indoor air and condenses the refrigerant during the heating operation.

As shown in FIG. 11, the second heat exchanger 122 is arranged on the leeward side of the total heat exchanger 20 of the air supply passage 10ad. Here, when the outside air does not exchange the total heat with the indoor air in the total heat exchanger 20 and the temperature does not change, such as during drying operation, if the outside air is supplied to the room as supply air as it is, the indoor temperature rises in the summer. In winter, the room temperature drops. Therefore, in such a case, the evaporation temperature or the condensation temperature is controlled. Specifically, in the summer, the evaporation temperature is lowered to lower the temperature of the supply air after passing through the second heat exchanger 122, and in the winter, the condensation temperature is raised to lower the second heat exchanger 122. Raises the temperature of the supply air after passing through. By doing so, even when the outside air does not exchange the total heat with the room air in the total heat exchanger 20 and the temperature does not change, such as during dry operation, the temperature of the supply air can be lowered or raised to raise the room temperature. Can be kept constant.

The suction pressure sensor 116 is provided on the suction side of the compressor 111, and detects the suction pressure for calculating the evaporation temperature during the cooling operation. The evaporation temperature is a saturation temperature calculated from the suction pressure detected by the suction pressure sensor 116.

The condensation temperature sensor 153 is provided in the second heat exchanger 122 and detects the condensation temperature during the heating operation.

In addition, in order to detect the evaporation temperature during the cooling operation, a temperature sensor may be provided in the first heat exchanger 113 instead of the suction pressure sensor 116. Further, in order to detect the condensation temperature during the heating operation, a pressure sensor may be provided on the discharge side of the compressor 111 instead of the condensation temperature sensor 153.

A control flow for identifying an abnormal factor of the ventilation device 1 according to the second embodiment will be described with reference to FIG.

FIG. 12 is a diagram showing a control flow for identifying an abnormal factor of the ventilation device 1 according to the second embodiment. It is assumed that normal operation is performed at the start of the control flow shown in FIG.

(Step S201)
The control device 30 calculates the current temperature efficiency ηnow based on each air temperature detected by the outside air temperature sensor 51, the supply air temperature sensor 52, and the indoor air temperature sensor 53.

(Step S202)
The control device 30 determines whether or not the difference between the current temperature efficiency ηnow and the reference value ηst is larger than 0. When the control device 30 determines that the difference between the current temperature efficiency ηnow and the reference value ηst is larger than 0, it is determined that the difference is greater than 0, and the process proceeds to step S203. On the other hand, when the control device 30 determines that the difference between the current temperature efficiency ηnow and the reference value ηst is 0 or less, it determines that it is normal and ends this control flow.

(Step S203)
The control device 30 stops the exhaust fan 13 and starts the drying operation. Further, the control device 30 notifies the notification unit 37 that the drying operation is being performed. Further, the control device 30 controls the evaporation temperature or the condensation temperature according to the outside air temperature. That is, when the outside air temperature is equal to or higher than the predetermined value in the summer, the operating frequency of the compressor 111 and the opening degree of the throttle device 121 are controlled so that the evaporation temperature drops to the predetermined value or lower. Further, when the outside air temperature is equal to or less than a predetermined value in winter, the operating frequency of the compressor 111 and the opening degree of the throttle device 121 are controlled so that the condensation temperature rises to the predetermined value or more. Although an example of stopping the exhaust fan 13 in order to start the drying operation has been described here, the supply air fan 11 may be stopped.

(Step S204)
The control device 30 determines whether or not a certain time has elapsed after starting the drying operation. When the control device 30 determines that a certain time has elapsed after starting the drying operation, the total heat exchanger 20 is determined to be dry, and the process proceeds to step S205. On the other hand, when the control device 30 determines that a certain time has not elapsed since the start of the drying operation, it is determined that the total heat exchanger 20 is not dry, and the process of step S204 is performed again.

Here, in the process of step S204, the control device 30 determines that the total heat exchanger 20 has dried after a certain period of time has elapsed after the start of the drying operation, but the present invention is not limited thereto. For example, the control device 30 may determine that the total heat exchanger 20 is dry when the difference between the supply air temperature T _SA and the outside air temperature _TO A becomes 0 and the temperature efficiency η = 0.

(Step S205)
The control device 30 operates the exhaust fan 13 and starts normal operation. Further, the control device 30 notifies the notification unit 37 that the normal operation is being performed. Further, the control device 30 controls the evaporation temperature or the condensation temperature according to the outside air temperature. That is, when the outside air temperature is equal to or higher than the predetermined value in the summer, the operating frequency of the compressor 111 and the opening degree of the throttle device 121 are controlled so that the evaporation temperature drops to the predetermined value or lower. Further, when the outside air temperature is equal to or less than a predetermined value in winter, the operating frequency of the compressor 111 and the opening degree of the throttle device 121 are controlled so that the condensation temperature rises to the predetermined value or more.

(Step S206)
The control device 30 calculates the current temperature efficiency ηnow based on each air temperature detected by the outside air temperature sensor 51, the supply air temperature sensor 52, and the indoor air temperature sensor 53.

(Step S207)
The control device 30 determines whether or not the difference between the current temperature efficiency ηnow and the reference value ηst is larger than 0. When the control device 30 determines that the difference between the current temperature efficiency ηnow and the reference value ηst is larger than 0, it is determined that the abnormality is due to the decrease in air volume, and the process proceeds to step S208. On the other hand, when the control device 30 determines that the difference between the current temperature efficiency ηnow and the reference value ηst is 0 or less, it is determined that there is no abnormality due to the decrease in air volume, and this control flow is terminated. Before ending the control flow, the control device 30 may notify the notification unit 37 that the abnormality is due to dew condensation or freezing.

(Step S208)
The control device 30 notifies the notification unit 37 that the abnormality is caused by the decrease in air volume.

FIG. 13 is a schematic side view showing the configuration of a modified example of the ventilation device 1 according to the second embodiment.

In the modified example of the ventilation device 1 according to the second embodiment, as shown in FIG. 13, the first heat exchanger 113 is arranged on the windward side of the total heat exchanger 20 of the air supply passage 10ad.

Then, during the drying operation, the air taken in from the outside air port 10a is heated by the heat released from the first heat exchanger 113 functioning as a condenser, that is, the heat of condensation, and then supplied to the total heat exchanger 20. To. Therefore, by arranging the first heat exchanger 113 on the windward side of the total heat exchanger 20 of the air supply passage 10ad, the time required for drying the total heat exchanger 20 during the drying operation can be shortened.

As described above, in the ventilation device 1 according to the second embodiment, the compressor 111, the flow path switching device 112, the first heat exchanger 113, the throttle device 121, and the second heat exchanger 122 are connected by pipes, and the refrigerant circulates. A refrigerant circuit 101 is provided, the second heat exchanger 122 is arranged on the leeward side of the total heat exchanger 20 of the air supply passage 10ad, and the control device 30 is detected by the first temperature sensor 51 during the drying operation. The evaporation temperature or the condensation temperature is controlled according to the temperature.

According to the ventilation device 1 according to the second embodiment, the evaporation temperature or the condensation temperature is controlled according to the temperature detected by the first temperature sensor 51 during the drying operation. Therefore, even when the outside air is not totally heat exchanged with the room air by the total heat exchanger 20 and the temperature does not change, the room temperature can be kept constant by lowering or raising the temperature of the supply air.

Further, in the ventilation device 1 according to the second embodiment, the first heat exchanger 113 is arranged on the windward side of the total heat exchanger 20 of the air supply passage 10ad.

According to the ventilation device 1 according to the second embodiment, since the first heat exchanger 113 is arranged on the wind side of the total heat exchanger 20 of the air supply passage 10ad, it is taken in from the outside air port 10a during the drying operation. The generated air is heated by the heat of condensation and then supplied to the total heat exchanger 20. Therefore, the time required for drying the total heat exchanger 20 during the drying operation can be shortened.

1 Ventilation device, 10 casing, 10a outside air port, 10ad air supply path, 10b exhaust port, 10bc exhaust path, 10c return air port, 10d air supply port, 11 air supply fan, 11ad air supply path, 11bc exhaust port, 12 supply Qi fan motor, 13 exhaust fan, 14 exhaust fan motor, 20 total heat exchanger, 30 control device, 31 storage unit, 32 extraction unit, 33 calculation unit, 34 comparison unit, 35 judgment unit, 36 control unit, 37 notification unit , 41 air supply filter, 42 exhaust filter, 51 outside air temperature sensor, 52 supply air temperature sensor, 53 indoor air temperature sensor, 54 exhaust temperature sensor, 101 refrigerant circuit, 111 compressor, 112 flow path switching device, 113 first heat Exchanger, 116 suction pressure sensor, 121 throttle device, 122 second heat exchanger, 153 condensate temperature sensor.

Claims (9)

1. A casing in which an air supply path through which the air blown from the air supply port passes and an exhaust path through which the air blown out from the exhaust port passes are formed.
   A total heat exchanger, which is arranged in the casing and exchanges heat between the air flowing through the air supply passage and the air flowing through the exhaust passage.
   The first temperature sensor that detects the air temperature on the inlet side of the air supply passage, and
   A second temperature sensor that detects the air temperature on the outlet side of the air supply passage, and
   A third temperature sensor that detects the air temperature on the inlet side of the exhaust passage,
   If the temperature efficiency of the first temperature sensor, the second temperature sensor, and the total heat exchanger calculated based on each air temperature detected by the third temperature sensor is larger than the reference value, an abnormality occurs. A ventilation device equipped with a control device for determining that the temperature is high.
2. An air supply fan that allows air to flow through the air supply path,
   It is equipped with an exhaust fan that allows air to flow through the exhaust passage.
   The control device is
   If it is determined that the abnormality has occurred during normal operation in which both the air supply fan and the exhaust fan are operated,
   The ventilation device according to claim 1, wherein a drying operation is performed in which either the air supply fan or the exhaust fan is stopped.
3. The drying operation is
   The ventilation device according to claim 2, which is an operation of stopping only the exhaust fan.
4. The drying operation is
   The ventilation device according to claim 2, wherein only the air supply fan is stopped.
5. The control device is
   After a certain period of time has passed since the drying operation was started,
   The temperature efficiency is calculated based on each air temperature detected by the first temperature sensor, the second temperature sensor, and the third temperature sensor, and if the temperature efficiency is larger than the reference value, an abnormality due to a decrease in air volume is performed. The ventilation device according to any one of claims 2 to 4, wherein it is determined that an abnormality has occurred due to dew condensation or freezing when the temperature efficiency is equal to or lower than the reference value.
6. Equipped with a notification unit
   The control device is
   The ventilation device according to any one of claims 2 to 5, wherein the notification unit notifies that the drying operation is being performed during the drying operation.
7. The control device is
   If it is determined that an abnormality has occurred due to dew condensation or freezing, the notification unit notifies that fact.
   The ventilation device according to claim 6, which is subordinate to claim 5, in which when it is determined that an abnormality has occurred due to a decrease in air volume, the notification unit notifies the fact.
8. A compressor, a flow path switching device, a first heat exchanger, a throttle device, and a second heat exchanger are connected by piping and equipped with a refrigerant circuit in which refrigerant circulates.
   The second heat exchanger is arranged on the leeward side of the total heat exchanger in the air supply passage.
   The control device is
   The ventilation device according to any one of claims 1 to 7, wherein the evaporation temperature or the condensation temperature is controlled according to the temperature detected by the first temperature sensor during the drying operation.
9. The ventilation device according to claim 8, wherein the first heat exchanger is arranged on the windward side of the total heat exchanger in the air supply passage.

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