JPH09287848A - Heat-exchange type ventilation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform comfortable ventilation with low humidity during a summer season and a rainy season and to prevent excessive reduction of an indoor temperature caused by cooling dehumidification. SOLUTION: A heat-exchanger 5 is located between a feed rout 3 to feed outside air to the interior of a room 2 of a building 1 and an exhaust route 4 to discharge indoor air to the outside of a housing. A dehumidifier 6 to effect cooling dehumidification is arranged at the part, situated further outdoor than the heat-exchanger 5, of the feed route 3. A reheater 7 to heat feed air is arranged at the part, situated further indoor than the heat-exchanger 5, of the feed route 3. The dehumidifier 6 and the reheater 7 are connected to a common heat pump type condenser unit 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchange type ventilation device for centralized heat recovery ventilation and dehumidification in a building such as a house.

[0002]

2. Description of the Related Art In recent years, with the improvement of airtightness and heat insulation of a house, an active ventilation system has been demanded. For this reason, even in houses, systems for centralized ventilation of the entire building by installing ducts in the ceiling and the like are gradually being adopted. FIG. 5 shows an example thereof. The ventilation system in the figure is
The heat recovery ventilation and ventilation cooling are performed, and the air supply path 5
1, a heat exchanger 53 is provided between the exhaust passage 52 and the exhaust passage 52, and a dehumidifier 54 including a cooling device is provided in the air supply passage 51. The heat exchanger 53 exchanges heat between the supply air and the exhaust air to reduce energy loss due to ventilation. The dehumidifier 54 is generally arranged on the indoor side of the heat exchanger 53 for the purpose of cooling the supply air.

However, in a climate of high humidity and heavy rain like Japan, the method of supplying the cooled air to the room as shown in the figure causes the outside air supplied to the room to have high humidity, and the summer or the rainy season. Sometimes I cannot provide comfortable ventilation. Moreover, since the cooling air having such a high humidity and a large temperature difference from the air around the duct is caused to flow, dew condensation is likely to occur around the equipment and the duct, and a countermeasure against it is necessary. There is also a problem of dew condensation at the outlet to the room. Further, since heavy air with high humidity is transported, the duct diameter becomes large, and a large piping space is required in the back of the ceiling or the like.

In order to solve such a problem, the applicant of the present invention has proposed the following heat exchange type ventilation device with a dehumidifying function (Japanese Patent Publication No. 7-65776). This is, as shown in FIG. 6, provided with a dehumidifier 54 in a portion of the air supply path 51 on the outdoor side of the heat exchanger 53. According to this,
The high-temperature and high-humidity fresh outside air is cooled and dehumidified by the dehumidifier 54, and the temperature thereof is raised by the exhaust heat of the room by the heat exchanger 53, and then supplied to the room. Therefore, the outside air that has been cooled and dehumidified is supplied to the room as dry air having a low relative humidity due to the temperature rise, and comfortable ventilation can be performed.
In addition, since dehumidification is performed on the outside air side of the heat exchanger and dry air is sent in this way, there is little problem of dew condensation around the equipment, ducts, outlets, and the like.

[0005]

However, even if the temperature of the air cooled by the dehumidifier 54 rises in the heat exchanger 53 due to the exhaust heat in the room, it does not rise to a sufficient temperature, and the room temperature drops due to dehumidification. Sometimes it's too much.

The present invention solves the above problems and provides a comfortable ventilation with a low humidity, less hindrance to dew condensation around equipment, ducts, etc., and a heat exchange type that can prevent an excessive decrease in indoor temperature. The purpose is to provide a ventilation device. It is another object of the present invention to minimize heat loss and prevent the room temperature from falling too low.

[0007]

The structure of the present invention will be described with reference to FIG. 1 corresponding to an embodiment. This heat exchange type ventilator has an air supply path (3) for supplying the outside air indoors and an exhaust path (4) for discharging the indoor air to the inside of these paths (3), (4). A dehumidifier provided with a heat exchanger (5) for exchanging heat between the supply air and the exhaust gas flowing through the air, and cooling and dehumidifying the supply air to a portion of the supply path (3) on the outdoor side of the heat exchanger (5). (6) is provided, and a reheater (7) for heating the supply air is provided in a portion of the supply air passage (3) closer to the indoor side than the heat exchanger (5). According to this configuration, the high-temperature and high-humidity fresh outside air is cooled and dehumidified by the dehumidifier (6), heated by the heat of the exhaust air in the room by the heat exchanger (5), and then supplied to the room. Therefore, the outside air that has been cooled and dehumidified is supplied to the room as dry air having a low relative humidity due to the temperature rise, and comfortable ventilation can be performed.
Moreover, since dehumidification is performed on the outside air side of the heat exchanger (5) and dry air is sent in this way, there is little problem of dew condensation around the equipment, ducts, blowout ports and the like. The temperature rise due to heat exchange also reduces the temperature difference between the air inside the duct and the air around the duct such as the back of the hut or the ceiling, which also makes the problem of dew condensation less likely to occur. Further, since light air with low humidity is transported, the duct diameter can be small. When the room temperature drops too much due to the dehumidifying cooling, the reheater is operated to raise the temperature of fresh air again and supply it to the room. This allows
The room temperature is prevented from falling too much.

In the above structure, the dehumidifier (6) and the reheater (7) have coils for circulating the refrigerant, and these coils are connected to a common heat pump type condenser unit (9). It is preferable. Thus, by connecting the dehumidifier (6) and the reheater (7) to the common condenser unit (9), cooling by the dehumidifier (6) and heating by the reheater (7) are mutually performed. Since waste heat is used, extra heat energy is unnecessary and energy efficiency is good. Further, in this configuration, the condenser unit (9) includes the parallel circuit (29) of the expansion valve (17) and the check valve (28), the compressor (14), and the outdoor air heat exchanger (16). It is preferable that the flow system of the refrigerant in the refrigerant circuit (20) can be switched between the dehumidifying operation system and the heating operation system by the flow system switching means (26). The dehumidifying operation system includes a compressor (14), a reheater (7), an outdoor air heat exchanger (16), a check valve (28),
The flow order of the dehumidifier (6) and the compressor (14) becomes
The heating operation system includes a compressor (14), a reheater (7),
Dehumidifier (6), expansion valve (17), outdoor air heat exchanger (1
6) and the flow order of the compressor (14). As a result, the dehumidifier (6) can also be used for heating and the heat exchange ventilator can be used for heating.

Further, in this structure, a bypass passage (20) is provided in the refrigerant circuit (20) in parallel with the reheater (7).
It is preferable that j) is provided and reheat bypass switching means (30) for selectively flowing the refrigerant is provided in the bypass passage (20j) and the reheater (7). In this case, a temperature sensor (34) is provided indoors, and the detected temperature of the temperature sensor (34) is compared with a set temperature in the operating state of the dehumidifying operation system, and the reheat bypass switching is performed when the detected temperature is low. Switching means (30) into a state of flowing to said reheater (7),
When the detected temperature is high, the reheat bypass switching means (3
Reheat judging means (31) for switching 0) to a state of flowing to the bypass passage (20j) is provided. This makes it possible to control the reheating and stop reheating in accordance with the room temperature without requiring the operation of the occupants, and to maintain the room at a comfortable temperature while achieving ventilation.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. As shown in the conceptual diagram of FIG. 4, this heat exchange type ventilator ventilates outside air from the indoor 2 of the building 1.
A heat exchanger 5 is provided between the air supply path 3 for supplying air to the air and the exhaust path 4 for discharging indoor air to the outside, and cooling and dehumidifying is performed on a portion of the air supply path 3 on the outdoor side of the heat exchanger 5. Dehumidifier 6
Is provided, and the reheater 7 for heating the supply air is provided in a portion of the supply path 3 which is closer to the indoor side than the heat exchanger 5. The reheater 7 comprises an indoor air heat exchanger.

FIG. 3 shows an example of the appearance of this ventilation device. The heat exchanger 5 is a ceiling-suspended type that has a blower built therein.
The dehumidifier 6 and the reheater 7 are indoor units of a heat pump type air conditioner and each have a coil (not shown) for circulating a refrigerant. A heat retaining duct is used for the air supply path 3 and the exhaust path 4. The heat exchanger 5 and the dehumidifier 6 may be incorporated in a common casing to form a dehumidifying / heat exchanging device, and the reheater 7 may also be incorporated in the common casing.

In the example of FIG. 1, the heat exchanger 5, the dehumidifier 6, and the reheater 7 are incorporated into a common housing to form an outside air processing unit 8, and a blower 12 is provided at the outside air inlet OA.
A blower 13 is provided at the exhaust port EA. Portions of the air supply path 3 and the exhaust path 4 inside the casing may be air passages partitioned by partition plates or may be configured by pipes. The outside air processing unit 8 is connected to a condenser unit 9 of a heat pump type air conditioner by a plurality (four) of refrigerant pipes 10.
An operation valve 11 is provided at each refrigerant pipe connection port of the condenser unit 9.

The condenser unit 9 can be switched between a dehumidifying operation and a heating operation, and includes a compressor 14, an accumulator 15, an outdoor air heat exchanger 16, and a parallel circuit 29 of an expansion valve 17 and a check valve 28. And a four-way switching valve 21 is provided. The outdoor air heat exchanger 16 is provided with a motor-driven fan 18. The refrigerant circuit 20 that connects the condenser unit 9 and each part of the outside air processing unit 8 has the following circuit parts and various valves. The solid arrow attached to the refrigerant circuit 20 indicates the refrigerant flow direction of the dehumidifying operation system, and the broken arrow indicates the refrigerant flow direction of the heating operation system.

The outlet of the compressor 14 is connected to the refrigerant inlet of the reheater 7 at the circuit portion 20a, and the refrigerant outlet of the reheater 7 is connected to the first port a of the four-way switching valve 21 at the circuit portion 20b. ing. The second port b of the four-way switching valve 21 is connected to one refrigerant port of the outdoor air heat exchanger 16 via the circuit portion 20c. The other refrigerant port of the outdoor heat exchanger 16 is connected to the parallel circuit 29 of the expansion valve 17 and the check valve 28 at the circuit portion 20d, and the dehumidifier 6 of the dehumidifier 6 is connected from this parallel circuit 29 through one circuit portion 20e. It is connected to one refrigerant port. The other refrigerant port of the dehumidifier 6 is connected to the third port c of the four-way switching valve 21 at the circuit portion 20f. The fourth port d of the four-way switching valve 21 is connected to the inlet of the compressor 14 from the circuit portion 20g via the accumulator 15. The four-way switching valve 21 is capable of switching between a state in which the ports a and b and the ports c and d are opened and a state in which the ports a and c and the ports b and d are opened.

The circuit portion 20a on the discharge side of the compressor 20 is
A branched circuit portion 20h is connected to the circuit portion 20e between the expansion valve 17 and the dehumidifier 6, and a hot gas bypass valve 22 and a check valve 23 are provided on the way. In the circuit portion 20e, a parallel connection circuit of a check valve 25 and a line resistance 24 is provided between the expansion valve 17 and a connection portion with the circuit portion 20h.

A circuit portion 20 on the discharge side of the compressor 14 is also provided.
The first control valve SV1 is provided at a on the reheater 7 side of the branch portion of the circuit portion 20h, and the third control valve SV3 is provided in parallel with the first control valve SV1. Between the parallel circuit portion of these control valves SV1 and SV3 and the branch portion of the circuit portion 20h, from the circuit portion 20a to the bypass passage 20j.
Is branched and connected to the circuit portion 20b on the return side from the reheater 7. The second control valve SV is provided in the bypass passage 20j.
2 are provided. Each of the control valves SV1 to SV3 is an electromagnetic on-off valve.

The refrigerant circuit 20 has the above-mentioned circuit configuration.
It is configured to be switchable between the dehumidifying operation system and the heating operation system,
In addition, the reheater 7 and the bypass passage 20j can be switched to a state of selectively flowing. The flow system switching means 26 for switching between the dehumidifying operation system and the heating operation system is composed of a four-way switching valve 21 and first and second control valves SV1 and SV2. The reheat bypass switching means 30 includes the second and third
Control valves SV2 and SV3.

The electrical control system will be described. Control means 27
Is composed of an electronic circuit or the like, and has a mode switching means 31 and a reheat determination means 32. The mode switching means 31 is
It is a means for switching between the dehumidifying operation mode in which the flow system switching means 26 is set to the dehumidifying operation system and the heating operation mode in which it is set to the heating operation system, and further, it is possible to switch to the simple ventilation mode. The mode selection of the mode switching means 32 is performed by the operation means 33 such as a switch board. In the dehumidification mode selected state, the reheat determination means 31 compares the temperature detected by the temperature sensor 34 provided in a predetermined ventilation target room of the indoor 2 with a set temperature (for example, 22 ° C.), and when the detected temperature is low, The reheat bypass switching means 30 is switched to the state of flowing to the reheater 7, and when the detected temperature is high, the reheat bypass switching means 30 is switched to the state of flowing to the bypass 20j.
FIG. 2 shows the control states of the control valves SV1 to SV3, etc. by the mode switching means 31 and the reheat determination means 31.

The operation of the above configuration will be described. First, the wind system will be explained. During the dehumidifying operation, fresh outside air flowing into the air supply path 3 is dehumidified by the dehumidifier 6, heat-exchanged with indoor exhaust by the heat exchanger 5, and then introduced indoors. Therefore, the outside air that has been cooled and dehumidified has its relative humidity lowered due to the temperature rise and is supplied to the room, so that comfortable ventilation can be performed.
When the indoor temperature drops too much, the reheater 7 is brought into a heated state, and the air after passing through the heat exchanger 5 is heated and introduced into the room.
This prevents the indoor temperature from dropping too much. During the heating operation, the dehumidifier 6 is in a heating state, and the fresh outside air flowing into the air supply path 3 is slightly heated by the dehumidifier 6 and the heat exchanger 5
After recovering the heat in step 1, the reheater 7 is used to heat the temperature. During the ventilation operation, the condenser unit 9 is stopped (hence, the compressor 14 is stopped), and the heat recovery operation of only the heat exchanger 5 is performed.

The operation of the refrigerant system will be described. Switching between the dehumidifying operation and the heating operation is performed by the four-way switching valve 21 and the control valve SV1,
It is performed by switching SV2. The solid arrow indicates the dehumidification operation, and the chain arrow indicates the heating operation. The control valve SV3 is used when reheating during the dehumidifying operation. That is, as shown in FIG. 2, in the heating operation, the control valve SV1 is turned on and the control valves SV2 and SV3 are turned off. Therefore, the heating operation system is the compressor 1
4, the reheater 7, the dehumidifier 6, the expansion valve 17, the outdoor air heat exchanger 16, the accumulator 15, and the compressor 14 in that order. In the dehumidifying operation, the flow is switched depending on the room temperature as shown in FIG. When the room temperature is equal to or lower than the set temperature (22 ° C.), the control valves SV1 and SV2 are turned off and the control valve SV3 is turned on. Therefore, the refrigerant flow is the compressor 14, the reheater 7, the outdoor air heat exchanger 16, the check valve 17, the dehumidifier 6,
The accumulator 15 and the compressor 14 flow in this order, and the indoor supply air is heated by the reheater 7. When the room temperature is equal to or higher than the set temperature (22 ° C.), the control valve SV1 is turned off, the control valve SV2 is turned on, and the control valve SV3 is turned off.
Therefore, the refrigerant flow in the dehumidifying operation system passes from the compressor 14 through the bypass 20j and is not heated by the reheater 7.

The hot gas bypass valve 22 bypasses the hot gas as necessary so that the low pressure is not lowered too much for the purpose of preventing frost formation on the dehumidifier 6 during the dehumidifying operation. That is, the low pressure is always maintained at a predetermined pressure (for example, 3.5 kg / cm ² ) or more. However, when the low pressure is high, the hot gas bypass valve 22 is closed.

[0022]

EFFECT OF THE INVENTION The heat exchange type ventilation device of the present invention has a supply air path for supplying outside air indoors and an exhaust air path for discharging indoor air outdoors, and supply air and exhaust air flowing through these paths. A heat exchanger for exchanging heat with the heat exchanger is provided, and a dehumidifier for cooling and dehumidifying the supply air is provided on a portion outside the heat exchanger in the air supply path, and more than the heat exchanger in the air supply path. Since a reheater that heats the supply air is installed in the indoor side, comfortable ventilation with low humidity can be performed, there is little hindrance to dew condensation around the equipment and ducts, and moreover the indoor temperature is prevented from dropping too much. can do. When the dehumidifier and the reheater are connected to a common condenser unit, waste heat is used for cooling by the dehumidifier and heating by the reheater.
Energy efficient. If the condenser unit can be switched between the dehumidifying operation system and the heating operation system, the dehumidifier can also be used for heating in addition to the reheater, and this heat exchange type ventilation device can be used for heating. it can. If a bypass path is provided in parallel with the reheater and the reheat bypass switching means is provided, and if the reheat determination means that switches the reheat bypass switching means according to the room temperature is provided, the operation of the resident is particularly required. It is possible to maintain a comfortable temperature inside the room while performing ventilation by controlling reheat and stop of reheat depending on the room temperature.

[Brief description of drawings]

FIG. 1 is a configuration explanatory view showing a refrigerant circuit, an air path, and an electric control system of a heat exchange type ventilation device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a control state of each part by the mode switching means and the reheat determination means.

FIG. 3 is a perspective view of an external configuration example of a heat exchange type ventilation device.

FIG. 4 is an explanatory diagram of a conceptual configuration of a heat exchange type ventilation device.

FIG. 5 is an explanatory diagram of a conceptual configuration of a conventional example.

FIG. 6 is an explanatory diagram of a conceptual configuration of another conventional example.

[Explanation of symbols]

2 ... Indoor, 3 ... Air supply path, 4 ... Exhaust path, 5 ... Heat exchanger, 6 ... Dehumidifier, 7 ... Dehumidifier, 8 ... Outside air processing unit,
9 ... Condenser unit, 14 ... Compressor, 16 ... Outdoor air heat exchanger, 17 ... Expansion valve, 20 ... Refrigerant circuit, 20j ... Bypass passage, 21 ... Four-way switching valve, 26 ... Flow system switching means,
28 ... Check valve, 29 ... Parallel circuit, 30 ... Reheat bypass switching means, 31 ... Reheat determination means, 34 ... Temperature sensor, SV
1-SV3 ... Control valve

Claims (4)

[Claims] 1. A heat exchanger for exchanging heat between the supply air and the exhaust air flowing between the supply air path for supplying the outside air indoors and the exhaust path for discharging the indoor air outdoors. Provided,
A dehumidifier that cools and dehumidifies the air supply is provided in an area on the outdoor side of the heat exchanger of the air supply path, and a reheater that heats the air supply to an area on the indoor side of the heat exchanger of the air supply path. Heat exchange type ventilator equipped with. 2. The dehumidifier and the reheater each have a coil for circulating a refrigerant, and the coils of the dehumidifier and the reheater are connected to a common heat pump type condenser unit. Heat exchange type ventilator. 3. The condenser unit has a parallel circuit of an expansion valve and a check valve, a compressor, and an outdoor air heat exchanger,
Also, the flow system of the refrigerant in the refrigerant circuit can be switched to a dehumidifying operation system and a heating operation system by the flow system switching means, and the dehumidifying operation system includes a compressor, a reheater, and outdoor air heat exchange. The flow order of the compressor, the check valve, the dehumidifier, and the compressor is the flow order, and the heating operation system is the flow order of the compressor, the reheater, the dehumidifier, the expansion valve, the outdoor air heat exchanger, and the compressor. The heat exchange-type ventilation device according to claim 2, wherein 4. A bypass path is provided in the refrigerant circuit in parallel with the reheater, and reheat bypass switching means for selectively flowing a refrigerant is provided in the bypass path and the reheater, and a temperature sensor is installed indoors. Provided, the temperature detected by the temperature sensor is compared with the set temperature in the operating state in the dehumidifying operation system, and when the detected temperature is low, the reheat bypass switching means is switched to a state of flowing to the reheater. The heat exchange type ventilation device according to claim 3, further comprising reheat determination means for switching the reheat bypass switching means to a state of flowing to the bypass passage when the temperature is high.