HEAT EXCHANGE TYPE VENTILATION DEVICE

TECHNICAL FIELD

The present invention relates to a heat exchange type ventilation device having a heat exchange element.

BACKGROUND ART

Recently, along with global warming, emphasis is placed on the energy saving performance in the housing field. Among the kinds of energy consumption of a house, energy consumption for hot water supply, illumination, and cooling and heating are relatively large. Accordingly, a technology of reducing such energy consumption is eagerly desired.

When focusing on energy consumption of cooling and heating, there are heat (cold in the case of cooling) escaped from a skeleton of a house and heat escaped through ventilation. Heat escaped from the skeleton of a house has been largely reduced due to significant improvements in the heat insulation property and the airtightness of a house in the last several decades. On the other hand, in order to reduce heat escaped through ventilation, a heat exchange type ventilation device that allows heat exchange between supplied air and discharged air is effective. A heat exchange type ventilation device includes a heat exchange element that allows heat exchange between the supplied air and the discharged air.

A heat exchange type ventilation device is particularly demanded in a cold district where there is a large temperature difference between an inside and an outside of a room. However, when the outside air is in low temperature in a cold district, frost is generated inside a heat exchange element. This causes a problem that clogging is likely to be caused in an air discharge path. This is because the warm and humid air inside a room is cooled to be in low temperature, and the moisture in the air is frozen. In particular, frosting is remarkable on an air discharge path side in a region where an inlet of an air supply path and an outlet of the air discharge path are in contact with each other via a heat exchanger plate inside the heat exchange element.

As a typical countermeasure against frosting, a heat exchange type ventilation device for a cold district introduce outside air to a heat exchange element after heating the outside air by a heater. Moreover, in a heat exchange type ventilation device for a cold district, when frosting is caused in a heat exchange element, the frost is melted (hereinafter referred to as “defrosted”) by circulating warm indoor air inside the heat exchange type ventilation device. However, there are problems that energy consumption is increased when a heater is used, and ventilation cannot be performed during defrosting.

Against such problems, consideration has been made to prevent clogging due to frosting in an air discharge path inside a heat exchange element even if the outside air is in low temperature, by improving a ratio between air supply volume and air discharge volume of the heat exchange type ventilation device.

As a conventional heat exchange type ventilation device of this type, one in which control is made to increase warm air discharge volume and reduce cold air supply volume, when frosting is caused inside a heat exchange element, has been known (for example, see Patent Literature 1).

Such a heat exchange type ventilation device will be described below with reference to FIG. 10.

As illustrated in FIG. 10, heat exchange type ventilation device 101 includes supply air blowing means 102, discharge air blowing means 103, and heat exchange element 107. Supply air blowing means 102 supplies outdoor air to an indoor space. Discharge air blowing means 103 discharges indoor air to an outdoor space. Heat exchange element 107 includes a heat exchanger plate 106 for exchanging total heat. Heat exchanger plate 106 separates air supply path 104 through which a supply air flow generated by supply air blowing means 102 flows, from air discharge path 105 through which a discharge air flow generated by discharge air blowing means 103 flows.

Heat exchange type ventilation device 101 is provided with temperature sensor 108 that measures temperature of the outdoor air. Heat exchange type ventilation device 101 allows heat exchange by reducing cold air supply volume while maintaining warm air discharge volume, according to the measured temperature of the outdoor air. Thereby, as the temperature of the entire heat exchange element 107 rises, clogging due to frosting is suppressed in heat exchange element 107.

CITATION LIST
Patent Literature

PTL 1: Unexamined Japanese Patent Publication No. 2015-135199

SUMMARY OF THE INVENTION

In such a conventional heat exchange type ventilation device, the air discharge volume is larger than the air supply volume. Accordingly, an outlet side of the air discharge path has negative pressure compared with an inlet side of the air supply path, due to a pressure loss of an air flow flowing inside the heat exchange element. Accordingly, the heat exchanger plate separating the air discharge path from the air supply path is bent toward the air discharge path side, whereby an opening area of the air discharge path becomes smaller. This causes a problem that clogging due to frosting is likely to be caused in the air discharge path.

In view of the above, an object of the present invention is to provide a heat exchange type ventilation device capable of suppressing clogging due to frosting in an air discharge path.

A heat exchange type ventilation device according to one aspect of the present invention includes a supply air blower, a discharge air blower, a heat exchange element, and a pressure regulator. The supply air blower supplies outdoor air to an indoor space. The discharge air blower discharges indoor air to an outdoor space. The heat exchange element includes a heat exchanger plate. The heat exchanger plate separates an air supply path through which a supply air flow generated by the supply air blower flows, from an air discharge path through which a discharge air flow generated by the discharge air blower flows, and allows sensible heat or total heat to be exchanged between the air supply path and the air discharge path. The pressure regulator is positioned upstream of the heat exchange element in the air supply path, and regulates pressure of the supply air flow.

The heat exchange type ventilation device according to one aspect of the present invention can suppress clogging due to frosting in the air discharge path.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 schematically illustrates an exemplary installation of a heat exchange type ventilation device according to an exemplary embodiment.

FIG. 2 is a schematic plan view illustrating a structure of the heat exchange type ventilation device according to the exemplary embodiment.

FIG. 3 is a perspective view of a total heat exchange element of the heat exchange type ventilation device according to the exemplary embodiment.

FIG. 4 is an exploded perspective view of part of the total heat exchange element of the heat exchange type ventilation device according to the exemplary embodiment.

FIG. 5 is a conceptual diagram illustrating an air discharge path of a typical total heat exchange element.

FIG. 6A is a schematic cross-sectional view illustrating a vicinity of an outlet of an air discharge path in a total heat exchange element of a conventional heat exchange type ventilation device.

FIG. 6B is a schematic cross-sectional view illustrating a state where frost is generated in the vicinity of the outlet of the air discharge path in the total heat exchange element of the conventional heat exchange type ventilation device.

FIG. 7A is a schematic cross-sectional view illustrating a vicinity of an outlet of an air discharge path in a total heat exchange element of a heat exchange type ventilation device according to the exemplary embodiment.

FIG. 7B is a schematic cross-sectional view illustrating a state where frost is generated in the vicinity of the outlet of the air discharge path in the total heat exchange element of the heat exchange type ventilation device according to the exemplary embodiment.

FIG. 8 is a schematic plan view illustrating another structure of a heat exchange type ventilation device according to the exemplary embodiment.

FIG. 9 is a schematic plan view illustrating another structure of a heat exchange type ventilation device according to the exemplary embodiment.

FIG. 10 is a schematic plan view illustrating a structure of a conventional heat exchange type ventilation device.

FIG. 11 schematically illustrates an exemplary installation of a heat exchange type ventilation system according to another exemplary embodiment.

FIG. 12 is schematic plan view illustrating a structure of a total heat exchange type ventilation device of the heat exchange type ventilation system according to the other exemplary embodiment.

FIG. 13 is a perspective view of the total heat exchange element of the heat exchange type ventilation system according to the other exemplary embodiment.

FIG. 14 is an exploded perspective view of part of the total heat exchange element of the heat exchange type ventilation system according to the other exemplary embodiment.

FIG. 15 a diagram illustrating an exemplary configuration of the heat exchange type ventilation system according to the other exemplary embodiment.

FIG. 16 a diagram illustrating another exemplary configuration of a heat exchange type ventilation system according to the other exemplary embodiment.

FIG. 17 a diagram illustrating another exemplary configuration of a heat exchange type ventilation system according to the other exemplary embodiment.

DESCRIPTION OF EMBODIMENTS

Thereby, the pressure regulator can regulate the pressure of the supply air flow so as to lower the pressure of the air supply path side. Accordingly, bending of the heat exchanger plate toward the air discharge path side is suppressed, and the opening area of the air discharge path is expanded. Therefore, clogging due to frosting in the air discharge path is suppressed.

Further, a heat exchange type ventilation device according to one aspect of the present invention includes a temperature detector and a controller. The temperature detector detects temperature of outdoor air. The controller causes the pressure regulator to regulate the pressure of the supply air flow, based on the temperature of the outdoor air detected by the temperature detector.

Thereby, when the temperature detector detects temperature of the outdoor air at which freezing is expected to be caused inside the heat exchange element, the pressure of the supply air flow is regulated by the pressure regulator such that the pressure of the air supply path side is lowered. Accordingly, bending of the heat exchanger plate toward the air discharge path side is suppressed, and the opening area of the air discharge path is expanded. Therefore, clogging due to frosting in the air discharge path is suppressed according to the temperature of the outdoor air.

Further, a heat exchange type ventilation device according to one aspect of the present invention includes a differential pressure detector and a controller. The differential pressure detector detects a differential pressure between a vicinity of an inlet of an air supply path in a heat exchange element and a vicinity of an outlet of an air discharge path in the heat exchange element. The controller causes a pressure regulator to regulate pressure of the supply air flow, in response to the differential pressure detected by the differential pressure detector.

Thereby, the pressure of the supply air flow is regulated by the pressure regulator such that the pressure of the air supply path side is lowered, in response to the differential pressure detected by the differential pressure detector. Accordingly, the pressure of the inlet side of the air supply path is kept lower than the pressure of the outlet side of the air discharge path in the heat exchange element. This means that the pressure of the inlet side of the air supply path is kept lower regardless of the magnitude of a pressure loss in each air path as a whole caused by clogging in each air path due to dirt deposited on the each air path, bending of each air path, a length of each air path, and the like. Accordingly, bending of the heat exchanger plate toward the air discharge path side is suppressed, and clogging due to frosting in the air discharge path is suppressed.

In a heat exchange type ventilation device according to one aspect of the present invention, a pressure regulator is a damper configured to adjust an opening of the damper.

Thereby, the pressure of the supply air flow in the heat exchange element is regulated by the opening of the damper that is a simple mechanism. Therefore, it is possible to provide a heat exchange type ventilation device in which clogging due to frosting is suppressed, at a lower price.

In a heat exchange type ventilation device according to one aspect of the present invention, a supply air blower has a control function to keep the air volume constant regardless of a pressure change in the supply air flow.

Thereby, even when the pressure of the supply air flow is regulated, the heat exchange type ventilation device can realize ventilation operation with constant air volume.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.

EXEMPLARY EMBODIMENTS

In FIG. 1, heat exchange type ventilation device 2 is provided inside house 1.

Heat exchange type ventilation device 2 discharges air inside rooms (hereinafter referred to as indoor air) to the outdoor space, as illustrated by black arrows.

Heat exchange type ventilation device 2 also supplies air outside rooms (hereinafter referred to as outdoor air) to the indoor space, as illustrated by white arrows.

In this way, heat exchange type ventilation device 2 performs ventilation. At the time of ventilation, heat exchange type ventilation device 2 transmits heat of indoor air to be discharged to the outdoor space, to outdoor air to be supplied to the indoor space. Thereby, heat exchange type ventilation device 2 suppresses unnecessary heat discharge.

As illustrated in FIG. 2, heat exchange type ventilation device 2 includes a body case 3 having inner air port 6, air discharge port 7, outer air port 9, and air supply port 10. Heat exchange type ventilation device 2 also includes, inside body case 3, total heat exchange element 4 serving as a heat exchange element, air discharge fan 5 serving as a discharge air blower, and air supply fan 8 serving as a supply air blower. Heat exchange type ventilation device 2 drives air discharge fan 5 to suck indoor air from inner air port 6. Then, heat exchange type ventilation device 2 discharges the sucked indoor air from air discharge port 7 to the outdoor space via total heat exchange element 4 and air discharge fan 5. This means that air discharge fan 5 discharges indoor air to the outdoor space. Discharge air flow 14 generated by air discharge fan 5 flows through air discharge path 20 that allows inner air port 6 and air discharge port 7 to communicate with each other.

Heat exchange type ventilation device 2 also drives air supply fan 8 to suck outdoor air from outer air port 9. Then, heat exchange type ventilation device 2 supplies the sucked outdoor air to the indoor space from air supply port 10 via total heat exchange element 4 and air supply fan 8. This means that air supply fan 8 supplies outdoor air to the indoor space. Supply air flow 15 generated by air supply fan 8 flows through air supply path 21 that allows outer air port 9 and air supply port 10 to communicate with each other.

Total heat exchange element 4 includes a plurality of layered molded items 13, as illustrated in FIGS. 3 and 4. Each of molded items 13 is a member formed by attaching heat exchanger plate 12 to space holding ribs 11. This means that a plurality of molded items 13 are layered with spaces held by space holding ribs 11. Discharge air flow 14 and supply air flow 15 flow through alternately every other layer with the space held by space holding ribs 11. This means that heat exchanger plate 12 separates air supply path 21 from air discharge path 20. As discharge air flow 14 and supply air flow 15 flow through while sandwiching molded item 13 to which heat exchanger plates 12 are attached, heat exchange and moisture exchange are performed via heat exchanger plates 12. As described above, total heat exchange element 4 includes heat exchanger plate 12. Heat exchanger plate 12 allows air supply path 21 and air discharge path 20 to exchange total heat between them.

Here, a mechanism of frosting caused in a typical heat exchange element will be described in detail with reference to FIG. 5. FIG. 5 is a conceptual diagram illustrating air discharge path 20 of a typical total heat exchange element. In the winter, indoor air contains humidity due to heating and human expiration, and outdoor air is dry. In that case, when discharge air flow 14 and supply air flow 15 flow through while sandwiching molded item 13 to which heat exchanger plates 12 (see FIG. 4) are attached, heat and moisture of discharge air flow 14 are transferred to supply air flow 15 via heat exchanger plates 12. At that time, temperature of discharge air flow 14 is lowered by supply air flow 15 having low temperature. When relative humidity of discharge air flow 14 having lowered temperature exceeds 100%, dew condensation is generated. When the temperature of discharge air flow 14 further drops down to a degree below zero, the dew condensation is frozen to be frost.

A region where frosting is likely to be caused is a region as illustrated by oblique lines in FIG. 5. In more detail, frosting is likely to be caused on air discharge path 20 side of a region where an outlet side of air discharge path 20, through which discharge air flow 14 flows, and an inlet side of air supply path 21, through which supply air flow 15 flows, are in contact with each other via heat exchanger plate 12. This is because discharge air flow 14 in this region first exchanges heat with low-temperature supply air flow 15, and is cooled most.

More detailed description will be given with user of FIGS. 6A and 6B. FIG. 6A is a schematic cross-sectional view illustrating a vicinity of an outlet of air discharge path 20 in a total heat exchange element of a conventional heat exchange type ventilation device. FIG. 6B is a schematic cross-sectional view illustrating a state where frost F is generated in the vicinity of the outlet of air discharge path 20 in the total heat exchange element of the conventional heat exchange type ventilation device. FIGS. 6A and 6B are schematic cross-sectional views taken along a plane orthogonal to a flowing direction of discharge air flow 14 (see FIG. 4).

As illustrated in FIG. 6A, when supply air flow 15 flows through air supply path 21 of total heat exchange element 4, a pressure loss is caused in air supply path 21. Thereby, pressure of the outlet side of air supply path 21 becomes lower than pressure of the inlet side of air supply path 21. Similarly, when discharge air flow 14 flows through air discharge path 20 of total heat exchange element 4, pressure of the outlet side of air discharge path 20 becomes lower than pressure of the inlet side of air discharge path 20. In general, the pressure of the outlet side of each air path 20, 21 is determined depending on a pressure loss due to bending of each air path and a length of each air path. However, a pressure loss due to bending of each air path and a length of each air path is smaller compared with a pressure loss caused when each air flow 14, 15 flows through each air path 20, 21 of total heat exchange element 4. Accordingly, the pressure of the outlet side of each air path 20, 21 becomes lower than the pressure of the inlet side of each air path 20, 21 due to an effect of a pressure loss caused when each air flow 14, 15 flows through each air path 20, 21 of total heat exchange element 4. Therefore, the pressure of the outlet side of air discharge path 20 through which discharge air flow 14 flows becomes lower than the pressure of the inlet side of air supply path 21 through which supply air flow 15 flows. Accordingly, heat exchanger plate 12 is bent toward air discharge path 20 side, thereby an opening area of air discharge path 20 becomes smaller. Thereby, as illustrated in FIG. 6B, when frost F is generated in air discharge path 20, clogging is likely to be caused in air discharge path 20 of total heat exchange element 4.

In view of the above, as illustrated in FIG. 2, heat exchange type ventilation device 2 of the present invention includes damper 16 that is positioned upstream (that is, outer air port 9 side) of total heat exchange element 4 on air supply path 21 in body case 3, and serves as a pressure regulator that regulates pressure applied to heat exchanger plate 12. In other words, damper 16 regulates pressure of supply air flow 15.

By adjusting an opening of damper 16 to decrease it, an opening area of air supply path 21, through which supply air flow 15 flows, is reduced at damper 16. Therefore, a pressure loss in air supply path 21 at damper 16 is increased. In this way, as damper 16 lowers the pressure of supply air flow 15, the pressure in the vicinity of the inlet of air supply path 21 in total heat exchange element 4 is lowered.

FIG. 7A is a schematic cross-sectional view illustrating a vicinity of an outlet of air discharge path 20 in total heat exchange element 4 of heat exchange type ventilation device 2. FIG. 7B is a schematic cross-sectional view illustrating a state where frost F is generated in the vicinity of the outlet of air discharge path 20 in total heat exchange element 4 of heat exchange type ventilation device 2. FIGS. 7A and 7B are schematic cross-sectional views taken along a plane orthogonal to a flowing direction of discharge air flow 14.

As illustrated in FIG. 7A, when the pressure in the vicinity of the inlet of air supply path 21 in total heat exchange element 4 is lowered, bending of heat exchanger plate 12 toward air discharge path 20 side is suppressed. As a result, the opening area of air discharge path 20 is expanded. Thereby, as illustrated in FIG. 7B, even when frost F is generated in air discharge path 20, clogging is unlikely to be caused in air discharge path 20 of total heat exchange element 4.

In normal operation, the opening of damper 16 is adjusted to full open. On the other hand, when it is desirable to suppress frosting in total heat exchange element 4, the opening of damper 16 is adjusted to be decreased.

Further, as illustrated in FIG. 8, heat exchange type ventilation device 2 may include temperature sensor 17 as temperature detector, and controller 18. Temperature sensor 17 detects temperature of outdoor air. Controller 18 causes damper 16 to regulate the pressure in the vicinity of the inlet of air supply path 21 in total heat exchange element 4, based on the outdoor temperature detected by temperature sensor 17. This means that controller 18 causes damper 16 to regulate the pressure of supply air flow 15, based on the outdoor temperature detected by temperature sensor 17.

More specifically, controller 18 adjusts the opening of damper 16 to decrease it only when the temperature of the outdoor air detected by temperature sensor 17 is equal to or lower than temperature at which freezing is expected to be caused inside total heat exchange element 4. Thereby, as described above, the pressure in the vicinity of the inlet of air supply path 21 in total heat exchange element 4 is lowered, and bending of heat exchanger plate 12 toward air discharge path 20 side is suppressed, whereby clogging due to frosting in air discharge path 20 is suppressed. Controller 18 adjusts the opening of damper 16 to decrease it only when the temperature is equal to or lower than temperature at which freezing is expected to be caused inside total heat exchange element 4. Accordingly, a frequency of controlling damper 16 is reduced, whereby exhaustion of damper 16 is suppressed.

Further, as illustrated in FIG. 9, heat exchange type ventilation device 2 may include differential pressure gauge 19 serving as a differential pressure detector, and controller 18. Differential pressure gauge 19 detects a differential pressure between the vicinity of the inlet of air supply path 21 in total heat exchange element 4 and the vicinity of the outlet of air discharge path 20 in total heat exchange element 4. Controller 18 may adjust the opening of damper 16 in response to the differential pressure detected by differential pressure gauge 19. This means that controller 18 may cause damper 16 to regulate the pressure of supply air flow 15, in response to the differential pressure detected by differential pressure gauge 19.

More specifically, when differential pressure gauge 19 detects that the pressure in the vicinity of the inlet of air supply path 21 in total heat exchange element 4 is higher than the pressure in the vicinity of the outlet of air discharge path 20 in total heat exchange element 4, controller 18 adjusts the opening of damper 16 to decrease it. Thereby, as described above, the pressure in the vicinity of the inlet of air supply path 21 in total heat exchange element 4 is lowered, and bending of heat exchanger plate 12 toward air discharge path 20 side is suppressed, whereby clogging due to frosting in air discharge path 20 is suppressed. Accordingly, the pressure in the vicinity of the inlet of air supply path 21 in total heat exchange element 4 is kept lower than the pressure in the vicinity of the outlet of air discharge path 20 in total heat exchange element 4, regardless of the magnitude of a pressure loss caused by clogging in each air path due to dirt deposited on each air path 20, 21, bending of each air path, a length of each air path, and the like. This means that the opening area of air discharge path 20 of total heat exchange element 4 is enlarged, whereby clogging due to frosting in air discharge path 20 is suppressed.

Here, the inlet of air supply path 21 in total heat exchange element 4 is an inlet on outer air port 9 side of air supply path 21 in total heat exchange element 4. The outlet of air discharge path 20 in total heat exchange element 4 is an outlet on air discharge port 7 side of air discharge path 20 in total heat exchange element 4.

Moreover, by using damper 16 configured to adjust the opening as a pressure regulator, it is possible to provide heat exchange type ventilation device 2 capable of suppressing clogging due to frosting at a low price.

Further, air supply fan 8 may include a control function of making air volume constant, regardless of a change in the pressure of supply air flow 15. Thereby, heat exchange type ventilation device 2 can realize ventilation operation with constant air volume without depending on the pressure of supply air flow 15 regulated by damper 16.

As air supply fan 8, there is a fan having a DC motor. A fan having a DC motor can realize a control function of making the air volume constant, and is likely to suppress power consumption.

It should be noted that while total heat exchange element 4 is a cross-flow type heat exchange element in the present exemplary embodiment, it may be a hexagonal heat exchange element (not illustrated) in which a counter-flow type and a cross-flow type are combined. Even in the case of a hexagonal heat exchange element, frosting is most likely to be caused in a region where the outlet side of air discharge path 20 and the inlet side of air supply path 21 are in contact with each other via heat exchanger plate 12. Accordingly, by reducing the pressure in the vicinity of the inlet of air supply path 21 in the heat exchange element, the opening area of air discharge path 20 is expanded, whereby clogging due to frosting in air discharge path 20 is suppressed.

It should be noted that while total heat exchange element 4 that allows heat exchange and moisture exchange is exemplary illustrated as a heat exchange element in the present exemplary embodiment, a sensible heat exchange element that allows only heat exchange may be used. This means that heat exchanger plate 12 may allow only sensible heat to be exchanged between air supply path 21 and air discharge path 20.

OTHER EXEMPLARY EMBODIMENTS

With the configuration of the aforementioned exemplary embodiment, an opening area of an air discharge path is enlarged, whereby clogging due to frosting in the air discharge path is suppressed. Meanwhile, in a cold district or in the winter time, outdoor air is drier than indoor air. As such, by increasing the supply volume of dry outdoor air, it is possible to suppress clogging due to dew condensation and freezing in the air discharge path.

A heat exchange type ventilation system, according to another exemplary embodiment, includes a heat exchange type ventilation device, an air supply volume regulator, a temperature detector, and an air supply volume controller. The heat exchange type ventilation device includes an outer air port for sucking outdoor air, an air supply port for supplying air to the indoor space, an inner air port for sucking indoor air, an air discharge port for discharging air to the outdoor space, an air supply path allowing the outer air port and the air supply port to communicate with each other, an air discharge path allowing the inner air port and the air discharge port to communicate with each other, and a heat exchange element that allows heat exchange between the air supply path and the air discharge path. The air supply volume regulator is provided on the air supply path, and regulates the air supply volume. The temperature detector detects outdoor temperature. The air supply volume controller controls the air supply volume regulator based on the outdoor temperature detected by the temperature detector.

The heat exchange type ventilation system according to the other exemplary embodiment is capable of suppressing clogging due to dew condensation and freezing in the air discharge path.

Thereby, when the temperature detector detects temperature at which freezing is expected to be caused inside the total heat exchange element, the air supply volume controller operates the air supply volume regulator. Then, the air volume of the dry supply air flow, flowing through the air supply path, is increased. Therefore, moisture transfer from the air discharge path to the air supply path is promoted, whereby generation of dew condensation in the air discharge path is suppressed. This means that clogging due to dew condensation and freezing in the air discharge path is suppressed.

Further, in the heat exchange type ventilation system according to the other exemplary embodiment, the temperature detector and the air supply volume controller are provided inside the air supply volume regulator. The air supply volume regulator is provided between the outer air port and the heat exchange element.

Thereby, the temperature detector can be provided with simple construction without wiring a long signal line.

Further, in the heat exchange type ventilation system according to the other exemplary embodiment, the temperature detector is provided between the outer air port and the heat exchange element. The air supply volume regulator and the air supply volume controller are provided between the heat exchange element and the air supply port. The temperature detector communicates with the air supply volume controller.

Thereby, dust contained in the outdoor air is cleaned by the heat exchanger plate of the heat exchange element. Therefore, the air supply volume regulator provided downstream of the heat exchange element is less likely to be soiled. Therefore, a frequency of maintenance of the air supply volume regulator can be reduced.

Further, in the heat exchange type ventilation system according to the other exemplary embodiment, the temperature detector is provided at a position adjacent to the heat exchange element.

Thereby, the temperature detector can detect the outdoor temperature at a position adjacent to the total heat exchange element. Accordingly, the temperature detector can detect the temperature at which freezing is caused inside the total heat exchange element, with high accuracy.

Hereinafter, another exemplary embodiment of the present invention will be described with reference to the drawings.

FIG. 11 is a schematic diagram illustrating two-story house 201 in which heat exchange type ventilation system 200 is provided. As illustrated in FIG. 11, house 201 is configured of a non-residential space where only air discharge is performed, and a residential space where both air supply and air discharge are performed. The non-residential space includes a toilet, a washroom, a bathroom, and the like, for example. The residential space includes a bedroom, a living room, and the like, for example. Heat exchange type ventilation system 200 includes total heat exchange type ventilation device 202 serving as a heat exchange type ventilation device, and air supply auxiliary fan 203 serving as an air supply volume regulator. Heat exchange type ventilation system 200 is provided behind a ceiling of house 201. In order to supply and discharge air to and from each room, total heat exchange type ventilation device 202 and air supply auxiliary fan 203 are connected with each room via a duct.

FIG. 12 schematically illustrates a structure of total heat exchange type ventilation device 202 of heat exchange type ventilation system 200. As illustrated in FIG. 12, total heat exchange type ventilation device 202 includes air supply fan 204, air discharge fan 205, and total heat exchange element 206. Air supply fan 204 sucks outdoor air and supplies it to the indoor space. Air discharge fan 205 sucks indoor air and discharges it to the outdoor space. Total heat exchange element 206 allows heat exchange and moisture exchange between supply air flow 207 sent by air supply fan 204 and discharge air flow 208 sent by air discharge fan 205. Total heat exchange type ventilation device 202 further includes outer air port 216 for sucking outdoor air, air supply port 217 for supplying air to the indoor space, inner air port 218 for sucking indoor air, air discharge port 219 for discharging air to the outdoor space, air supply path 220, and air discharge path 221. Air supply path 220 allows outer air port 216 and air supply port 217 to communicate with each other. Supply air flow 207 flows through air supply path 220. Air discharge path 221 allows inner air port 218 and air discharge port 219 to communicate with each other. Discharge air flow 208 flows through air discharge path 221.

Total heat exchange element 206 will be described below with use of FIGS. 13 and 14.

FIG. 13 is a perspective view of total heat exchange element 206 of total heat exchange type ventilation device 202. FIG. 14 is an exploded perspective view of part of total heat exchange element 206. As illustrated in FIGS. 13 and 14, total heat exchange element 206 includes a plurality of layered molded items 224. Each of molded items 224 is a member formed by attaching heat exchanger plate 223 to space holding ribs 222. This means that a plurality of molded items 224 are layered with spaces held by space holding ribs 222. Supply air flow 207 and discharge air flow 208 flow alternately every other layer with the space held by space holding ribs 222. As supply air flow 207 and discharge air flow 208 flow while sandwiching molded item 224 to which heat exchanger plates 223 are attached, heat exchange and moisture exchange are performed via heat exchanger plates 223. This means that total heat exchange element 206 allows heat exchange between air supply path 220 and air discharge path 221.

Here, a mechanism of causing freezing in total heat exchange element 206 will be described. In the winter, total heat exchange element 206 heats supply air flow 207 with use of heat of discharge air flow 208. Accordingly, discharge air flow 208 is cooled by supply air flow 207 on the contrary. When discharge air flow 208 is cooled down to a temperature below a freezing point, the moisture in discharge air flow 208 is saturated. Then, the moisture that cannot be held any more is condensed and adheres to total heat exchange element 206. Moreover, the condensed moisture is frozen because it is cooled down to a temperature below the freezing point. The frozen moisture blocks air discharge path 221 through which discharge air flow 208 of total heat exchange element 206 flows.

Meanwhile, by increasing the air volume of supply air flow 207 flowing through air supply path 220, it is possible to suppress blocking of air discharge path 221. Details will be described below.

Moisture transfer from discharge air flow 208 to supply air flow 207 is caused when absolute humidity of discharge air flow 208 is higher than absolute humidity of supply air flow 207. Absolute humidity is indicated by moisture weight contained in 1 kg of dry air. Here, with an increase of the air volume of supply air flow 207, moisture transfer from discharge air flow 208 having high absolute humidity to supply air flow 207 having low absolute humidity is promoted. Accordingly, as the moisture volume of discharge air flow 208 is reduced, saturation of moisture in discharge air flow 208 is suppressed, whereby dew condensation inside total heat exchange element 206 is suppressed.

FIG. 15 is a diagram illustrating an exemplary configuration of heat exchange type ventilation system 200. As illustrated in FIG. 15, heat exchange type ventilation system 200 includes total heat exchange type ventilation device 202, air supply auxiliary fan 203 serving as an air supply volume regulator, connection duct 209, temperature sensor 210 serving as a temperature detector, and outdoor air connection duct 213.

Air supply auxiliary fan 203 is provided to air supply path 220, and includes sirocco fan 211, and control board 212 serving as an air supply volume controller. More specifically, air supply auxiliary fan 203 and control board 212 are provided between air supply port 217 and total heat exchange element 206. Connection duct 209 is provided between total heat exchange element 206 and air supply auxiliary fan 203. Outdoor air connection duct 213 is provided between total heat exchange element 206 and outer air port 216. Temperature sensor 210 is provided inside outdoor air connection duct 213, and detects outdoor temperature. This means that temperature sensor 210 is provided between outer air port 216 and total heat exchange element 206. Temperature sensor 210 is electrically connected with control board 212 via signal line 214 that is an outdoor temperature communication member, and performs communication with control board 212. Control board 212 controls operation of sirocco fan 211 based on the outdoor temperature detected by temperature sensor 210. This means that control board 212 controls air supply auxiliary fan 203 based on the outdoor temperature detected by temperature sensor 210.

As temperature sensor 210, a known temperature detection means can be used. As temperature sensor 210, a thermocouple utilizing electromotive voltage generated in a connected portion of different types of metal, a resistance temperature detector, a heat measurement method using a semiconductor, or the like may be used, for example.

In this configuration, temperature at which freezing is expected to be caused inside total heat exchange element 206 is previously set to temperature Td. When outdoor temperature Tx detected by temperature sensor 210 is equal to or lower than temperature Td, control board 212 transmits a signal to operate sirocco fan 211. On the other hand, when temperature Tx is higher than temperature Td, control board 212 transmits a signal to stop sirocco fan 211. Thereby, when temperature sensor 210 detects temperature Td at which freezing is expected to be caused inside total heat exchange element 206, control board 212 controls operation of sirocco fan 211. Accordingly, the air volume of supply air flow 207 flowing through air supply path 220 is increased, thereby dew condensation and freezing inside total heat exchange element 206 are suppressed.

FIG. 16 is a diagram illustrating another exemplary configuration of heat exchange type ventilation system 200. As illustrated in FIG. 16, in the present exemplary configuration, temperature sensor 210 and control board 212 are provided inside air supply auxiliary fan 203. Air supply auxiliary fan 203 is provided between outdoor air connection duct 213 and total heat exchange element 206. This means that air supply auxiliary fan 203 is provided between outer air port 9 and total heat exchange element 206. With this configuration, temperature sensor 210 can be provided with simple construction without wiring long signal line 214.

FIG. 17 is a diagram illustrating another exemplary configuration of heat exchange type ventilation system 200. The present exemplary configuration differs from the exemplary configuration illustrated in FIG. 15 in the position where temperature sensor 210 is disposed. In the present exemplary configuration, temperature sensor 210 is disposed at a position adjacent to total heat exchange element 206. With this configuration, temperature sensor 210 can detect outdoor temperature in the vicinity of total heat exchange element 206. Accordingly, temperature sensor 210 can detect temperature at which freezing is caused inside total heat exchange element 206, with high accuracy.

In the present exemplary embodiment, while heat exchange type ventilation system 200 is provided behind the ceiling of house 201, it may be provided under the eaves of house 201 or in a machinery room.

As sirocco fan 211, another fan of a known type may be used. A fan to be used instead of sirocco fan 211 may be selected according to expected air volume and required static pressure.

While temperature sensor 210 performs communication with control board 212 via a wired connection using signal line 214, it may perform communication via a wireless connection. In the case where temperature sensor 210 performs communication via a wireless connection, as a degree of freedom in construction of temperature sensor 210 and control board 212 is increased, it is more preferable.

In FIG. 17, while temperature sensor 210 is provided upstream of sirocco fan 211, it may be provided downstream of sirocco fan 211. Even when temperature sensor 210 is provided downstream of sirocco fan 211, temperature sensor 210 can detect outdoor temperature. However, it is more preferable that temperature sensor 210 is provided upstream of sirocco fan 211 because temperature sensor 210 is less affected by heat generated by sirocco fan 211.

The heat exchange type ventilation system according to the present invention can suppress freezing of total heat exchange element. Therefore, the heat exchange type ventilation system is useful as a ventilation system.

INDUSTRIAL APPLICABILITY

The heat exchange type ventilation device according to the present invention can suppress clogging due to frosting effectively. Therefore, it is useful as a heat exchange type ventilation device having a heat exchange element.

REFERENCE MARKS IN THE DRAWINGS

- 1 house
- 2 heat exchange type ventilation device
- 3 body case
- 4 total heat exchange element (heat exchange element)
- 5 air discharge fan (discharge air blower)
- 6 inner air port
- 7 air discharge port
- 8 air supply fan (supply air blower)
- 9 outer air port
- 10 air supply port
- 11 space holding rib
- 12 heat exchanger plate
- 13 molded item
- 14 discharge air flow
- 15 supply air flow
- 16 damper (pressure regulator)
- 17 temperature sensor (temperature detector)
- 18 controller
- 19 differential pressure gauge (differential pressure detector)
- 20 air discharge path
- 21 air supply path
- 101 heat exchange type ventilation device
- 102 supply air blowing means
- 103 discharge air blowing means
- 104 air supply path
- 105 air discharge path
- 106 heat exchanger plate
- 107 heat exchange element
- 108 temperature sensor
- 200 heat exchange type ventilation system
- 201 house
- 202 total heat exchange type ventilation device
- 203 air supply auxiliary fan (air supply volume regulator)
- 204 air supply fan
- 205 air discharge fan
- 206 total heat exchange element (heat exchange element)
- 207 supply air flow
- 208 discharge air flow
- 209 connection duct
- 210 temperature sensor (temperature detector)
- 211 sirocco fan
- 212 control board (air supply volume controller)
- 213 outdoor air connection duct
- 214 signal line
- 216 outer air port
- 217 air supply port
- 218 inner air port
- 219 air discharge port
- 220 air supply path
- 221 air discharge path
- 222 space holding rib
- 223 heat exchanger plate
- 224 molded item

Number	Date	Country	Kind
2015-250155	Dec 2015	JP	national
2015-250157	Dec 2015	JP	national

HEAT EXCHANGE TYPE VENTILATION DEVICE

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