JP2013127343A - Desiccant ventilation fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a desiccant ventilation fan that prevents deposition of frost to surfaces of heat exchangers in an exhaust passage.SOLUTION: In a desiccant ventilation fan 10 comprising a sensible heat exchange rotor 13 for moving heat from a high-temperature side to a low-temperature side between an air feed passage 11 for taking air into a room and the exhaust passage 12 for discharging the air in the room, and second heat exchangers 16, 16a connected to first heat exchangers 14, 14a arranged at the downstream side of the sensible heat exchange rotor 13 along a flow of the air in the room in the exhaust passage 12 and existing in the air feed passage 11 via a refrigerant circuit 15, a temperature sensor 30 for measuring refrigerants sent to the second heat exchangers 16, 16a acting as evaporators is arranged in a refrigerant circuit 15, the sensible heat exchange rotor 13 moves the heat to the air feed passage 11 from the exhaust passage 12, and while the second heat exchangers 16, 16a act as the evaporators and when a measurement temperature of the temperature sensor 30 is not higher than a preset frosting prevention temperature, the sensible heat exchange rotor 13 is stopped and a temperature in the exhaust passage 12 is raised.

Description

The present invention relates to a desiccant ventilation fan that suppresses temperature drop in a room and ventilates the room while maintaining humidity.

As a result of the revision of the Building Standards Law, ventilation of 0.5 times / h or more is obligated in ordinary households as a countermeasure against sick house. As a ventilation system for ventilating a house, there is a desiccant ventilation fan that ventilates while suppressing a temperature drop in the room and maintaining the humidity in the room. A specific example is described in Patent Document 1.
The desiccant ventilation fan of Patent Document 1 is a desiccant rotor that moves moisture from the side having a higher relative humidity to the side having a lower relative humidity with respect to the indoor air flowing toward the outside in the exhaust path and the outside air flowing toward the room within the air supply path. A rotary desiccant dehumidifier and a rotary desiccant humidifier), and a sensible heat exchange rotor (rotary sensible heat exchanger) that moves the temperature from the high temperature side to the low temperature side.

A first refrigerant heat exchanger and a second refrigerant heat exchanger are arranged in the exhaust path and the air supply path, respectively. The first and second refrigerant heat exchangers are the first and second refrigerant heat exchangers, respectively. By switching the flow direction of the refrigerant in the refrigerant circuit connecting the refrigerant heat exchanger, one acts as an evaporator and the other acts as a condenser.
By causing the first refrigerant heat exchanger to act as an evaporator and the second refrigerant heat exchanger to act as a condenser, the room can be moisturized while being ventilated.

JP 2011-94904 A

However, the desiccant ventilation fan of Patent Document 1 is a first refrigerant that acts as an evaporator when performing an operation of moving heat from an exhaust path to an air supply path by a sensible heat exchange rotor while keeping the room moisturized in winter. Frost may adhere to the surface of the industrial heat exchanger.
This is because, in winter, the temperature of the refrigerant flowing into the first refrigerant heat exchanger is low, and the indoor air whose temperature has dropped through the sensible heat exchange rotor is sent to the first refrigerant heat exchanger. This is because the surface of the first heat exchanger for refrigerant may be below freezing point.
And if frost adheres to the surface of the 1st refrigerant | coolant heat exchanger, the flow volume of the indoor air discharged | emitted outside via an exhaust path will reduce, and the fall of ventilation will be caused.
This invention is made | formed in view of this situation, and it aims at providing the desiccant ventilation fan which prevents that frost adheres to the surface of the heat exchanger arrange | positioned in the exhaust path.

A desiccant ventilation fan according to the present invention that meets the above-described object is a sensible heat exchange rotor that moves heat from a high temperature side to a low temperature side between an air supply path for taking in outside air into a room and an exhaust path for discharging the air in the room, A second heat disposed in the exhaust path along the air flow in the room on the downstream side of the sensible heat exchange rotor and connected to the first heat exchanger in the supply path via a refrigerant circuit. In a desiccant ventilation fan comprising an exchanger, the refrigerant circuit is provided with a temperature sensor for measuring the temperature of the refrigerant sent to the second heat exchanger acting as an evaporator, and the sensible heat exchange rotor is provided from the exhaust passage. When the temperature measured by the temperature sensor is equal to or lower than a predetermined frost prevention temperature in a state where heat is transferred to the air supply path and the heat exchanger of the younger brother 2 acts as an evaporator. , Stop the sensible heat exchange rotor and the exhaust Raising the temperature of the inner.

In the desiccant ventilation fan according to the present invention, even when the sensible heat exchange rotor is stopped, when the temperature measured by the temperature sensor decreases and becomes a temperature lower by α ° C. than the frost prevention temperature, the refrigerant circuit It is preferable to stop the circulation of the refrigerant.

In the desiccant ventilation fan according to the present invention, the stopped sensible heat exchange rotor preferably starts to operate when the temperature measured by the temperature sensor is higher by β ° C. than the frost prevention temperature.

In the desiccant ventilation fan according to the present invention, the refrigerant circuit is provided with a temperature sensor for measuring the temperature of the refrigerant sent to the second heat exchanger acting as an evaporator, and the sensible heat exchange rotor is heated from the exhaust passage to the supply passage. And the sensible heat exchanger rotor is stopped when the temperature measured by the temperature sensor is equal to or lower than a predetermined frosting prevention temperature in a state where the heat exchanger of brother 2 is acting as an evaporator. Increase the temperature in the exhaust passage. Therefore, after the sensible heat exchange rotor is stopped, the second heat exchanger is supplied with air having a higher temperature than before the sensible heat exchange rotor is stopped, and frost adheres to the surface of the second heat exchanger. Can be prevented.

In the desiccant ventilation fan according to the present invention, even when the sensible heat exchange rotor is stopped, when the temperature measured by the temperature sensor decreases and becomes a temperature lower by α ° C. than the frost prevention temperature, the refrigerant is circulated in the refrigerant circuit. When the temperature is stopped, it is possible to prevent the low temperature refrigerant from being supplied to the second heat exchanger and suppress the temperature drop of the second heat exchanger, and frost adheres to the surface of the second heat exchanger. Can be prevented.

In the desiccant ventilation fan according to the present invention, when the stopped temperature of the sensible heat exchange rotor starts operating when the measured temperature of the temperature sensor is higher by β ° C. than the frost prevention temperature, the supply path from the exhaust path by the sensible heat exchange rotor The transfer of heat to can be resumed after the frost is not attached to the surface of the second heat exchanger.

It is explanatory drawing of the desiccant ventilation fan which concerns on one embodiment of this invention. It is a block diagram which shows the connection of a control means.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
As shown in FIG. 1, a desiccant ventilation fan 10 according to an embodiment of the present invention heats from a high temperature side to a low temperature side between an air supply path 11 for taking in outside air and an exhaust path 12 for discharging indoor air. Sensible heat exchange rotor 13 for moving the second heat exchanger, and a second heat exchanger disposed in the exhaust passage 12 and connected to the first heat exchangers 14 and 14a in the air supply passage 11 via the refrigerant circuit 15 16, 16a. Details will be described below.

As shown in FIG. 1, the desiccant ventilation fan 10 includes a housing 17 in which an air supply path 11 for sending outside air into the room and an exhaust path 12 for discharging indoor air to the outdoors are formed. A rotor 18 and a sensible heat exchange rotor 13 are provided.
The desiccant rotor 18 is disposed so as to straddle the air supply path 11 and the exhaust path 12, and is formed by laminating corrugated plate members, honeycomb members and the like, and has a structure through which air flowing through the air supply path 11 and the exhaust path 12 flows. ing. The surface constituent material of the desiccant rotor 18 is covered with a polymeric absorbent, or a hygroscopic material such as silica gel or zeolite.

An electric motor 19 shown in FIG. 2 is provided in the housing 17, and the desiccant rotor 18 is rotated by a driving force applied from the electric motor 19 from the side where the relative humidity of the air supply path 11 and the exhaust path 12 is high. Move moisture to the lower side.
The moisture absorbent adhering to the surface of the desiccant rotor 18 adsorbs moisture in the air and is heated to release the adsorbed moisture and regenerate the moisture.

As shown in FIG. 1, there are first heat exchangers 14, 14 a and a fan 20 in the air supply path 11. When the fan 20 is activated, outdoor outdoor air passes through the air supply path 11 and enters the room. Inflow. The first heat exchanger 14 is disposed on the upstream side of the first heat exchanger 14 a along the flow of air in the room in the air supply path 11.
Two second heat exchangers 16, 16 a and a fan 21 are arranged in the exhaust path 12. When the fan 21 is activated, indoor air is discharged to the outside via the exhaust path 12. The second heat exchanger 16 is on the upstream side of the second heat exchanger 16a along the flow of outside air in the exhaust passage 12.
And the 1st heat exchangers 14 and 14a and the 2nd heat exchangers 16 and 16a are connected in order by the refrigerant circuit 15 in which a refrigerant circulates.

The refrigerant circuit 15 is provided with a compressor 22 that compresses the refrigerant, a four-way valve 23 that switches a direction in which the refrigerant flows, and an expansion valve 24 that decompresses the refrigerant. The expansion valve 24 is disposed between the heat exchangers 14 and 16a.
As shown in FIG. 2, the desiccant ventilation fan 10 includes control means 25 connected to an electric motor 19, fans 20 and 21, a compressor 22, a four-way valve 23, and an expansion valve 24, and the control means 25 includes an operation panel 26. Is connected.
The control means 25 is composed of, for example, a microcomputer, and switches the four-way valve 23 in accordance with an input operation on the operation panel 26.

When the operation of starting the moisturizing operation is performed on the operation panel 26, the control means 25 causes the four-way valve 23, the refrigerant discharged from the compressor 22 to be the first heat exchangers 14 a and 14, the expansion valve 24, the second The heat exchangers 16a and 16 are sequentially returned to the compressor 22, and the compressor 22 is operated. The refrigerant in the refrigerant circuit 15 circulates in the refrigerant circuit 15 by the operation of the compressor 22.
During the moisturizing operation, the high-pressure gaseous refrigerant discharged from the compressor 22 passes through the first heat exchangers 14a and 14 and condenses, and then is brought into a low-pressure state by the expansion valve 24. 2 passes through the heat exchangers 16 a and 16, evaporates, and flows into the compressor 22. At this time, the first heat exchangers 14 and 14a act as condensers, and the second heat exchangers 16 and 16a act as evaporators.

Part of the gaseous refrigerant exiting the compressor 22 becomes liquid when passing through the first heat exchanger 14a, and the remainder that has not become liquid in the first heat exchanger 14a is first heat exchange. When passing through the vessel 14, it becomes liquid. The refrigerant that has become liquid as a whole is partially vaporized when passing through the second heat exchanger 16 a, and the rest is evaporated when passing through the second heat exchanger 16.

The desiccant rotor 18 absorbs moisture from the indoor air passing through the exhaust passage 12 and is heated by the condensation heat of the first heat exchanger 14 to release the absorbed moisture to the air supply passage 11. It will be in the state which can absorb moisture. As a result, the moisture moved to the desiccant rotor 18 from the indoor air flowing toward the outside through the exhaust path 12 returns to the room along with the outside air flowing toward the room through the air supply path 11. Therefore, the room is ventilated with humidity maintained.

On the other hand, when the dehumidifying operation start operation is performed on the operation panel 26, the control means 25 switches the state of the four-way valve 23 so that the refrigerant discharged from the compressor 22 is transferred to the second heat exchangers 16, 16a, It returns to the compressor 22 through the expansion valve 24 and the first heat exchangers 14 and 14a in this order. At this time, the first heat exchangers 14 and 14a function as evaporators, and the second heat exchangers 16 and 16a function as condensers.

As a result, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 22 passes through the second heat exchangers 16 and 16a and condenses to a low temperature, and then is brought into a low-pressure state by the expansion valve 24. The vapor passes through the first heat exchangers 14 and 14 a and returns to the compressor 22.
The desiccant rotor 18 absorbs moisture from the outside air passing through the air supply path 11 and is heated by the second heat exchanger 16 in the exhaust path 12 to release the absorbed moisture into the exhaust path 12. Therefore, the interior of the room is dehumidified with ventilation.

Further, the sensible heat exchange rotor 13 provided in the housing 17 is disposed across the air supply path 11 and the exhaust path 12 as shown in FIG. Similarly to the desiccant rotor 18, the sensible heat exchange rotor 13 is formed by laminating corrugated plate members, honeycomb members, and the like, and has a structure through which air flowing through the air supply path 11 and the exhaust path 12 flows.
An electric motor 27 connected to the control means 25 shown in FIG. 2 is provided in the housing 17, and the sensible heat exchange rotor 13 is rotated by the drive of the electric motor 27, and the outside air and the exhaust gas flowing in the air supply path 11 are exhausted. Heat is absorbed from the higher temperature side of the indoor air flowing through the passage 12, and is radiated to the lower temperature side.

The sensible heat exchange rotor 13 absorbs heat from indoor air discharged to the outside through the exhaust passage 12 when the outdoor temperature is lower than in the room (in winter), and releases the heat through the air supply passage 11. To do. The heat released in the air supply path 11 is carried into the room by the outside air flowing in the air supply path 11. Therefore, the room is in a state in which the room temperature is prevented from being lowered by ventilation.
The sensible heat exchange rotor 13 takes heat from the outside air flowing into the room through the air supply path 11 and discharges the heat to the exhaust path 12 when the outdoor temperature is higher than in the room (summer). Therefore, the outside air flowing through the air supply path 11 flows into the room after being cooled by the air supply path 11 and suppresses the temperature rise in the room.

In the present embodiment, the first heat exchanger 14, the desiccant rotor 18, the sensible heat exchange rotor 13, and the first heat exchanger 14 a are arranged in the air supply path 11 along the flow of outside air in the air supply path 11. Are arranged in order, and the sensible heat exchange rotor 13, the second heat exchanger 16, the desiccant rotor 18, and the second heat exchanger 16a are arranged in this order in the exhaust path 12 along the flow of air in the exhaust path 12. Has been.
Accordingly, during the moisturizing operation in winter, the outside air flowing in the air supply path 11 passes through the sensible heat exchange rotor 13 and rises in temperature, and then further rises in temperature due to the condensation heat of the first heat exchanger 14a. During the dehumidifying operation in the summer, the outside air flowing in the air supply passage 11 is cooled by passing through the sensible heat exchange rotor 13 and then further cooled by the evaporation heat of the first heat exchanger 14a. And flows into the room.

Further, as shown in FIG. 1, the air supply path 11 is provided with a temperature sensor 28 for measuring the temperature of the outside air taken into the air supply path 11 on the upstream side of the first heat exchanger 14. 12, a temperature / humidity sensor 29 is provided on the upstream side of the sensible heat exchange rotor 13 to measure the temperature and humidity of the indoor air taken into the exhaust passage 12.
The refrigerant circuit 15 is provided with a temperature sensor 30 that measures the temperature of the refrigerant circulating in the refrigerant circuit 15 between the second heat exchanger 16a and the expansion valve 24. The temperature sensor 30 measures the temperature of the refrigerant sent to the second heat exchangers 16 and 16a when the second heat exchangers 16 and 16a function as an evaporator.
The temperature sensor 28, the temperature / humidity sensor 29, and the temperature sensor 30 are connected to the control means 25 as shown in FIG.

Here, compared with other seasons in winter, the refrigerant circulating in the refrigerant circuit 15 and the indoor air flowing through the exhaust passage 12 have a low temperature, and the surface temperatures of the second heat exchangers 16 and 16a are low. And when frost adheres to the surface of the 2nd heat exchangers 16 and 16a by the fall of surface temperature, the flow volume of the indoor air which flows through the exhaust passage 12 will reduce, and the problem that ventilation amount will fall will be caused.
As solutions to this problem, 1) raise the temperature of the indoor air passing through the second heat exchangers 16 and 16a, and 2) low-temperature refrigerant flows into the second heat exchangers 16 and 16a. It is possible to stop doing.

When the sensible heat exchange rotor 13 absorbs heat in the exhaust passage 12 and dissipates heat in the air supply passage 11, and moves heat from the exhaust passage 12 to the air supply passage 11, the indoor air flowing in the exhaust passage 12 is The temperature is lowered by passing through the sensible heat exchange rotor 13. Further, in winter when the temperature of the refrigerant in the refrigerant circuit 15 is low, a moisturizing operation in which the second heat exchangers 16 and 16a function as an evaporator is usually performed.
In view of this, the sensible heat exchange rotor 13 transfers heat from the exhaust passage 12 to the air supply passage 11 and the second heat exchangers 16 and 16a act as evaporators. Is equal to or lower than a predetermined frost prevention temperature, the control means 25 stops the electric motor 27 and stops the sensible heat exchange rotor 13.

Due to the stop of the sensible heat exchange rotor 13, the air in the room passing through the second heat exchangers 16 and 16 a becomes higher than before the sensible heat exchange rotor 13 is stopped, and the surface of the second heat exchangers 16 and 16 a. The temperature rises. Therefore, it is possible to prevent frost from adhering to the surfaces of the second heat exchangers 16 and 16a.
The frosting prevention temperature can be determined by experiment, and in the present embodiment, is a temperature in the range of −1 to 3 ° C.

Even if the temperature of the indoor air passing through the second heat exchangers 16 and 16a is increased by stopping the sensible heat exchange rotor 13, the temperature of the refrigerant supplied to the second heat exchangers 16 and 16a decreases. If it continues, the surface temperature of the 2nd heat exchangers 16 and 16a will fall.
Therefore, when the control means 25 detects that the temperature measured by the temperature sensor 30 has decreased even when the sensible heat exchange rotor 13 is stopped and has become a temperature lower by α ° C. than the frost prevention temperature, The operation is stopped and the circulation of the refrigerant in the refrigerant circuit 15 is stopped. Thereby, since the inflow of the refrigerant to the second heat exchangers 16 and 16a stops, it is possible to prevent frost from adhering to the surfaces of the second heat exchangers 16 and 16a. α ° C. can be determined by experiments, and in the present embodiment, the temperature is in the range of 2 to 4 ° C.

The stopped compressor 22 is restarted by a command signal from the control means 25 when the temperature measured by the temperature sensor 30 becomes higher than the temperature obtained by subtracting α ° C. from the frost prevention temperature.
When the control means 25 detects that the temperature measured by the temperature sensor 30 is higher by β ° C. than the frosting prevention temperature after the sensible heat exchange rotor 13 is stopped, the control means 25 drives the electric motor 27 to drive the sensible heat exchange rotor 13. Start operation.
β ° C. can be determined by experiment, and in this embodiment, is a temperature in the range of 2 to 4 ° C.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and all changes in conditions and the like that do not depart from the gist are within the scope of the present invention.
For example, it is possible to provide only one heat exchanger in the air supply path and one heat exchanger in the exhaust path. Further, instead of the heat exchanger, an electric heater or other heating means may be used to heat the desiccant rotor so that moisture can be absorbed.

10: Desiccant ventilation fan, 11: Air supply path, 12: Exhaust path, 13: Sensible heat exchange rotor, 14, 14a: First heat exchanger, 15: Refrigerant circuit, 16, 16a: Second heat exchanger, 17: Housing, 18: Desiccant rotor, 19: Electric motor, 20, 21: Fan, 22: Compressor, 23: Four-way valve, 24: Expansion valve, 25: Control means, 26: Operation panel, 27: Electric motor, 28: Temperature sensor, 29: Temperature / humidity sensor, 30: Temperature sensor

Claims (3)

A sensible heat exchange rotor that moves heat from a high temperature side to a low temperature side between an air supply path that takes in outside air into the room and an exhaust path that discharges the air in the room, and a flow of air in the room in the exhaust path A desiccant ventilation fan comprising a second heat exchanger disposed downstream of the sensible heat exchange rotor and connected to a first heat exchanger in the air supply path via a refrigerant circuit,
The refrigerant circuit is provided with a temperature sensor for measuring the temperature of the refrigerant sent to the second heat exchanger acting as an evaporator, and the sensible heat exchange rotor transfers heat from the exhaust passage to the supply passage. And, when the heat exchanger of the younger brother 2 is acting as an evaporator, the sensible heat exchange rotor is stopped when the temperature measured by the temperature sensor is equal to or lower than a predetermined frosting prevention temperature. The desiccant ventilation fan characterized by raising the temperature in the exhaust passage. 2. The desiccant ventilation fan according to claim 1, wherein, even when the sensible heat exchange rotor is stopped, when the temperature measured by the temperature sensor decreases and becomes a temperature lower by α ° C. than the frost prevention temperature, the refrigerant A desiccant ventilation fan characterized by stopping circulation of the refrigerant in a circuit. The desiccant ventilation fan according to claim 1 or 2, wherein the stopped sensible heat exchange rotor starts to operate when a temperature measured by the temperature sensor is higher by β ° C than the frost prevention temperature. Desiccant ventilation fan.

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