Heat exchange type ventilation device

Abstract

To provide technique for improving efficiency of respective operations of plural kinds of operation modes of a heat exchange type ventilation device.SOLUTION: A supply air passage 7 conveys a supply air current 3 sucked from the outdoor side and blown out to the indoor side through a body case 11. An exhaust air passage 6 conveys an exhaust air current 2 sucked from the indoor side and blown out to the outdoor side through the body case 11. A circulation air passage 8 conveys a circulation air current 4 sucked from the indoor side and blown out again to the indoor side through the body case 11. A first heat exchanger 12 performs heat exchange between the supply air current 3 and the exhaust air current 2. A first temperature adjusting unit 34 cools or heats the supply air current 3 after passing through the first heat exchanger 12 on the basis of an operation mode. A second heat exchanger 35 performs heat exchange between the supply air current 3 after passing through the first temperature adjusting unit 34 and the circulation air current 4. A second temperature adjusting unit 38 cools or heats the supply air current 3 after passing through the second heat exchanger 35 on the basis of the operation mode.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, a heat exchange ventilation device that performs heat exchange between an intake air flow and an exhaust air flow during ventilation has been known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a heat exchange ventilation device has a plurality of types of operation modes, it is required to improve the efficiency of operations in each operation mode.

[0005] Therefore, the present disclosure solves the above problems and aims to provide a technique for improving the efficiency of operations of each of a plurality of types of operation modes provided in a heat exchange ventilation device.

Means for Solving the Problems

[0006] In order to solve the above problems, a heat exchange ventilation device according to an aspect of the present disclosure is a heat exchange ventilation device having a refrigeration cycle and capable of setting a plurality of operation modes, including an operation mode acquisition unit for acquiring an operation mode, an air supply intake for sucking air from the outside, an air supply outlet for blowing air into the room, an exhaust intake for sucking air from the room, an exhaust outlet for blowing air to the outside, a return air intake for sucking air from the room, and a return air outlet for blowing air into the room; a housing having an air supply duct communicating the air supply intake and the air supply outlet and conveying an air supply flow sucked from the outside and blown into the room through the housing, an exhaust duct communicating the exhaust intake and the exhaust outlet and conveying an exhaust flow sucked from the room and blown to the outside through the housing, and a return air duct communicating the return air intake and the return air outlet and conveying a return air flow sucked from the room and blown back into the room through the housing; a first heat exchanger for performing heat exchange between the air supply flow and the exhaust flow; a first temperature adjustment unit belonging to the refrigeration cycle and cooling or heating the air supply flow after passing through the first heat exchanger based on the operation mode acquired by the operation mode acquisition unit; a second heat exchanger for performing heat exchange between the air supply flow after passing through the first temperature adjustment unit and the return air flow; and a second temperature adjustment unit belonging to the refrigeration cycle and cooling or heating the air supply flow after passing through the second heat exchanger based on the operation mode acquired by the operation mode acquisition unit.

[0007] In addition, any combination of the above components, as well as those obtained by converting the expressions of the present disclosure among methods, devices, systems, recording media, computer programs, etc., are also effective as aspects of the present disclosure.

Effects of the Invention

[0008] According to the present disclosure, the efficiency of each operation of a plurality of types of operation modes provided in the heat exchange ventilation device can be improved.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The embodiments described below all show a preferred specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments, as well as the steps (processes) and the order of the steps, etc. are examples and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, the components not described in the independent claims indicating the most general concept of the present disclosure are described as arbitrary components. Also, in each figure, the same reference numerals are given to substantially the same configurations, and duplicate explanations are omitted or simplified.

[0011] Figures 1(a) and 1(b) show the configuration and the outline of the operation of the dehumidifying operation mode in the heat exchange type ventilation device 1. Figure 1(a) shows the configuration of the heat exchange type ventilation device 1. The heat exchange type ventilation device 1 includes an indoor unit 10 and an outdoor unit 32. The outdoor unit 32 is a device that compresses and expands the refrigerant. The outdoor unit 32 is provided outdoors. The outdoors (outside the house) is the outside of the building, and the indoors (inside the house) is the inside of the building. The outdoor unit 32 forms a refrigeration cycle 30 in which the refrigerant circulates between the indoor unit 10. Here, for example, an alternative refrigerant (HFC134a) is used as the refrigerant in the refrigeration cycle 30. Also, the connection of each device constituting the refrigeration cycle 30 is made, for example, by welding a copper pipe. The outdoor unit 32 includes a compressor 31, an expander 33 (first expander 33a, second expander 33b), an outdoor unit temperature adjustment unit 39 (outdoor evaporator 39a, outdoor condenser 39b), and a four-way valve 41.

[0012] The compressor 31 belongs to the refrigeration cycle 30 and is a device that pressurizes the refrigerant and raises the temperature of the refrigerant. The compressor 31 circulates the refrigeration cycle 30, that is, the refrigerant, by pressurizing the refrigerant.

[0013] The first expander 33a belongs to the refrigeration cycle 30 and is a device that depressurizes the refrigerant and lowers the temperature of the refrigerant. The first expander 33a can switch between an expansion state in which the refrigerant is depressurized and expanded and an open state in which the refrigerant passes through without being depressurized. The second expander 33b belongs to the refrigeration cycle 30 and is a device that depressurizes the refrigerant and lowers the temperature of the refrigerant. The second expander 33b can switch between an expansion state in which the refrigerant is depressurized and expanded and an open state in which the refrigerant is not depressurized.

[0014] The outdoor unit temperature adjustment unit 39 cools or heats the passing refrigerant with the outside air. The outdoor unit temperature adjustment unit 39 is provided in the internal flow path of the outdoor unit 32 between the expander 33 (the first expander 33a and the second expander 33b) and the four-way valve 41 described later in the refrigeration cycle. When the outdoor unit temperature adjustment unit 39 functions as an outdoor evaporator 39a, it introduces the expanded refrigerant and is heated by discharging cold air to the outside (the outside air). On the other hand, when the outdoor unit temperature adjustment unit 39 functions as an outdoor condenser 39b, it introduces the condensed refrigerant and is cooled by discharging heat to the outside.

[0015] The four-way valve 41 belongs to the refrigeration cycle 30 and is a member that switches the flow path of the refrigerant sent out from the compressor 31. The four-way valve 41 can switch between a flow path that allows the compressed refrigerant to flow to the first temperature adjustment unit 34 described later and a flow path that allows the refrigerant to flow to the outdoor unit temperature adjustment unit 39. When the compressed refrigerant flows to the first temperature adjustment unit 34, the four-way valve 41 guides the refrigerant that has flowed into the four-way valve 41 from the outdoor unit temperature adjustment unit 39 to the compressor 31 and guides the refrigerant that has flowed into the four-way valve 41 from the compressor 31 to the first temperature adjustment unit 34. Also, when the compressed refrigerant flows to the outdoor unit temperature adjustment unit 39, the four-way valve 41 guides the refrigerant that has flowed into the four-way valve 41 from the first temperature adjustment unit 34 to the compressor 31 and guides the refrigerant that has flowed into the four-way valve 41 from the compressor 31 to the outdoor unit temperature adjustment unit 39.

[0016] The indoor unit 10 exhausts to the outside and supplies air to the inside. The indoor unit 10 includes a main body case 11, an exhaust suction port 14, an exhaust blowout port 15, an exhaust air path 6, an air supply suction port 17, an air supply blowout port 18, an air supply air path 7, a return air suction port 60, a return air blowout port 62, a return air path 8, a first heat exchanger 12, a second heat exchanger 35, a first temperature adjustment unit 34, and a second temperature adjustment unit 38. The indoor unit 10 also includes an exhaust fan, an air supply fan, and a return air fan (not shown). The main body case 11 is the outer frame (housing) of the indoor unit 10. The main body case 11 is formed, for example, in a hollow box shape.

[0017] The exhaust air inlet 14 is an inlet that sucks the exhaust air flow 2 (air) from the outdoors into the indoor unit 10. The exhaust air inlet 14 is provided, for example, in a circular shape and a duct is connected thereto. The exhaust air outlet 15 is an outlet that blows the exhaust air flow 2 (air) from the indoor unit 10 to the outdoors. The exhaust air outlet 15 is provided, for example, in a circular shape and a duct is connected thereto. The exhaust air duct 6 is an air duct that communicates the exhaust air inlet 14 and the exhaust air outlet 15. Therefore, the exhaust air duct 6 conveys the exhaust air flow 2 flowing from the indoors to the outdoors. The exhaust fan (not shown) is a blower that guides the exhaust air flow 2 sucked from the exhaust air inlet 14 to the exhaust air outlet 15. The exhaust fan is composed of, for example, a sirocco fan.

[0018] The supply air inlet 17 is an inlet that sucks the supply air flow 3 (air) from the outdoors into the indoor unit 10. The supply air inlet 17 is provided, for example, in a circular shape and a duct is connected thereto. The supply air outlet 18 is an outlet that blows the supply air flow 3 (air) from the indoor unit 10 to each room indoors. The supply air outlet 18 is provided, for example, in a circular shape and a duct is connected thereto. The supply air duct 7 is an air duct that communicates the supply air inlet 17 and the supply air outlet 18. Therefore, the supply air duct 7 conveys the supply air flow 3 flowing from the outdoors to the indoors. The supply fan (not shown) is a blower that guides the supply air flow 3 sucked from the supply air inlet 17 to the supply air outlet 18. The supply fan is composed of, for example, a sirocco fan.

[0019] The return air inlet 60 is an inlet that sucks the return air flow 4 (air) from the indoors into the indoor unit 10. The return air inlet 60 is provided, for example, in a circular shape and a duct is connected thereto. The return air outlet 62 is an outlet that blows the return air flow 4 (air) from the indoor unit 10 to each room indoors. The return air outlet 62 is provided, for example, in a circular shape and a duct is connected thereto. The return air duct 8 is an air duct that communicates the return air inlet 60 and the return air outlet 62. Therefore, the return air duct 8 conveys the return air flow 4 sucked from the indoors, passing through the main body case 11 and then blown out to the indoors again. The return fan (not shown) is a blower that guides the return air flow 4 sucked from the return air inlet 60 to the return air outlet 62. The return fan is composed of, for example, a sirocco fan.

[0020] The first heat exchanger 12 performs heat exchange between the exhaust gas flow 2 and the supply air flow 3.

[0021] The first temperature control unit 34 is connected to the first heat exchanger 12 and belongs to the refrigeration cycle 30. When the first temperature control unit 34 functions as the first evaporator 34a, it introduces the expanded refrigerant and cools the supply air flow 3 after it has passed through the first heat exchanger 12. On the other hand, when the first temperature control unit 34 functions as the first condenser 34b, it introduces the condensed refrigerant and heats the supply air flow 3 after it has passed through the first heat exchanger 12.

[0022] The second heat exchanger 35 is connected to the first temperature control unit 34. The second heat exchanger 35 performs heat exchange between the supply air flow 3 after passing through the first temperature control unit 34 and before passing through the second temperature control unit 38, and the return air flow 4. The second heat exchanger 35 is, for example, a sheet heat exchanger.

[0023] The second temperature control unit 38 is connected to the second heat exchanger 35 and belongs to the refrigeration cycle 30. When the second temperature control unit 38 functions as the second evaporator 38a, it introduces the expanded refrigerant and cools the supply air flow 3 after it has passed through the first temperature control unit 34 (the second heat exchanger 35). On the other hand, when the second temperature control unit 38 functions as the second condenser 38b, it introduces the condensed refrigerant and heats the supply air flow 3 after it has passed through the first temperature control unit 34 (the second heat exchanger 35).

[0024] The heat exchange ventilation device 1 can realize a plurality of operation modes by controlling the first temperature control unit 34 and the second temperature control unit 38 belonging to the refrigeration cycle 30. The plurality of operation modes include, for example, a cooling operation mode, a heating operation mode, and a dehumidifying operation mode.

[0025] The control device 20 controls the compressor 31, the first expander 33a, and the second expander 33b independently. In other words, the control device 20 independently controls the heating or cooling in the first temperature control unit 34 belonging to the refrigeration cycle 30 and the heating or cooling in the second temperature control unit 38. Further, the control device 20 can control the four-way valve 41 to switch the circulation direction in the refrigeration cycle 30. Thus, the control device 20 controls the operation mode. In this embodiment, the control device 20 is built into the indoor unit 10 but may be provided outside the indoor unit 10.

[0026] The main body case 11 is also provided with an inclined bottom surface (not shown) and a water receiving portion. The inclined bottom surface is a part of the bottom surface of the main body case 11 and is inclined so that the moisture generated inside the indoor unit 10 flows to one side surface (not shown) side of the main body case 11. The inclined bottom surface is provided vertically below the second heat exchanger 35, the first temperature control unit 34, and the second temperature control unit 38. The water receiving portion is a member that collects the moisture guided to the one side surface side by the inclined bottom surface. The water receiving portion is provided on one side surface side of the main body case 11. The water receiving portion can discharge the collected moisture outdoors, for example, by connecting to a drain hose.

[0027] First, the case where the heat exchange and ventilation device 1 operates in the dehumidification operation mode among a plurality of operation modes will be described. When the set operation mode is the dehumidification operation mode, in the refrigeration cycle 30, the refrigerant circulates in the order of the compressor 31, the four-way valve 41, the outdoor unit temperature control unit 39, the first expander 33a, the second temperature control unit 38, the second expander 33b, the first temperature control unit 34, the four-way valve 41, and the compressor 31. In the case of the dehumidification operation mode, the first expander 33a is in an open state where it does not depressurize the refrigerant, and the second expander 33b is in an expansion state where it depressurizes the refrigerant.

[0028] Here, the outdoor unit temperature adjustment unit 39 functions as a condenser (outdoor condenser 39b) when the refrigerant compressed by the compressor 31 is introduced. Further, the first temperature adjustment unit 34 functions as an evaporator (first evaporator 34a) when the refrigerant compressed by the second expander 33b is introduced. Further, the second temperature adjustment unit 38 functions as a condenser (second condenser 38b) when the refrigerant compressed by the compressor 31 is introduced.

[0029] As a result, the configuration inside the main body case 11 is shown as in Fig. 1(b). Fig. 1(b) shows an outline of the operation in the dehumidifying operation mode of the heat exchange ventilation device 1. The first heat exchanger 12, the first evaporator 34a, the second heat exchanger 35, and the second condenser 38b are arranged in order. The supply air duct 7 is connected from the supply air inlet 17 to the supply air outlet 18 via the first heat exchanger 12, the first evaporator 34a, the second heat exchanger 35, and the second condenser 38b. Further, the exhaust air duct 6 is connected from the exhaust air inlet 14 to the exhaust air outlet 15 via the first heat exchanger 12. Furthermore, the return air duct 8 is connected from the return air inlet 60 to the return air outlet 62 via the second heat exchanger 35. The return air duct 8 may pass through the second condenser 38b (second temperature adjustment unit 38). Here, a return air intake switching unit 64 is provided at the return air inlet 60 of the return air duct 8. The return air intake switching unit 64 is an openable and closable lid that switches the opening and closing of the return air inlet 60.

[0030] The supply air flow temperature sensor 50 detects the temperature of the supply air flow 3 after passing through the first temperature adjustment unit 34 (first evaporator 34a) and before passing through the second heat exchanger 35. The supply air flow temperature sensor 50 has a communication function and transmits the detected temperature of the supply air flow 3 to a control device 20 (not shown). The indoor temperature sensor 52 detects the indoor temperature. The indoor temperature sensor 52 may detect the temperature of the return air flow 4 in the vicinity of the return air inlet 60 in the return air duct 8 as the indoor temperature. The indoor temperature sensor 52 has a communication function and transmits the detected indoor temperature to a control device 20 (not shown).

[0031] The control device 20 receives the temperature of the supply air flow 3 from the supply air flow temperature sensor 50 and the indoor temperature from the indoor temperature sensor 52. Further, the control device 20 includes an operation mode acquisition unit (not shown), and the operation mode acquisition unit acquires the currently set operation mode. The operation mode is one of, but not limited to, a dehumidification operation mode, a cooling operation mode, and a heating operation mode. Also, the operation mode is set by the user, for example. When the operation mode acquired by the operation mode acquisition unit of the control device 20 is the dehumidification operation mode, as described above, the first temperature adjustment unit 34 operates as the first evaporator 34a, the second temperature adjustment unit 38 operates as the second condenser 38b, and the outdoor unit temperature adjustment unit 39 operates as the outdoor condenser 39b.

[0032] When the operation mode acquired by the operation mode acquisition unit of the control device 20 is the dehumidification operation mode, regardless of the detection results of the supply air flow temperature sensor 50 and the indoor temperature sensor 52, the control device 20 selects the open state of the return air intake port 60 and does not select the closed state. The control device 20 transmits the selection result to the return air intake switching unit 64. The return air intake switching unit 64 has a communication function and opens the return air intake port 60 based on the selection result received from the control device 20. Thus, the return air intake switching unit 64 switches the opening and closing of the return air intake port 60 based on the operation mode acquired by the operation mode acquisition unit.

[0033] The supply air flow 3 sucked from the supply air intake port 17 is cooled (pre-cooled) by heat exchange with the exhaust air flow 2 in the first heat exchanger 12. The supply air flow 3 from the first heat exchanger 12 is cooled by the first evaporator 34a. As a result, the temperature of the supply air flow 3 becomes equal to or lower than the dew point temperature, and the supply air flow 3 condenses, so the moisture in the supply air flow 3 is removed. That is, dehumidification of the supply air flow 3 is performed by passing through the first evaporator 34a. The moisture generated inside the indoor unit 10 by the first evaporator 34a is collected in the water receiving part and discharged outdoors.

[0034] The supply air flow 3 from the first evaporator 34a undergoes heat exchange with the return air flow 4 in the second heat exchanger 35. As a result, the supply air flow 3 is heated. The supply air flow 3 from the second heat exchanger 35 is heated by the second condenser 38b to suppress excessive temperature drop due to dehumidification.

[0035] The exhaust air flow 2 sucked in from the exhaust air inlet 14 undergoes heat exchange with the supply air flow 3 in the first heat exchanger 12. As a result, the exhaust air flow 2 is heated. The return air flow 4 sucked in from the return air inlet 60 undergoes heat exchange with the supply air flow 3 in the first heat exchanger 12, and the return air flow 4 that has undergone heat exchange is returned indoors from the return air outlet 62. Since a part of the indoor air blown out from the heat exchange ventilation device 1 circulates, the dehumidification efficiency is improved.

[0036] Next, the case where the heat exchange ventilation device 1 operates in the cooling operation mode among a plurality of operation modes will be described. FIGS. 2(a)-(b) show the configuration and operation outline of the cooling operation mode in the heat exchange ventilation device 1. FIG. 2(a) shows the configuration of the heat exchange ventilation device 1. When the set operation mode is the cooling operation mode, in the refrigeration cycle 30, the refrigerant circulates in the order of the compressor 31, the four-way valve 41, the outdoor unit temperature regulator 39, the first expander 33a, the second temperature regulator 38, the second expander 33b, the first temperature regulator 34, the four-way valve 41, and the compressor 31. In the case of the cooling operation mode, the first expander 33a and the second expander 33b are in an expanded state in which the refrigerant is depressurized.

[0037] Here, the outdoor unit temperature regulator 39 functions as a condenser (outdoor condenser 39b) when the refrigerant compressed by the compressor 31 is introduced. Also, the first temperature regulator 34 functions as an evaporator (first evaporator 34a) when the refrigerant expanded by the second expander 33b is introduced. Further, the second temperature regulator 38 functions as an evaporator (second evaporator 38a) when the refrigerant expanded by the first expander 33a is introduced.

[0038] As a result, the configuration inside the main body case 11 is shown as in Fig. 2(b). Fig. 2(b) shows an outline of the operation in the cooling operation mode of the heat exchange type ventilation device 1. The first heat exchanger 12, the first evaporator 34a, the second heat exchanger 35, and the second evaporator 38a are arranged in order. The supply air duct 7 is connected from the supply air inlet 17 to the supply air outlet 18 via the first heat exchanger 12, the first evaporator 34a, the second heat exchanger 35, and the second evaporator 38a. Also, the exhaust air duct 6 is connected from the exhaust air inlet 14 to the exhaust air outlet 15 via the first heat exchanger 12. Further, the return air duct 8 is connected from the return air inlet 60 to the return air outlet 62 via the second heat exchanger 35.

[0039] The control device 20 receives the temperature of the supply air flow 3 from the supply air flow temperature sensor 50 and the indoor temperature from the indoor temperature sensor 52. Also, when the operation mode acquired by the operation mode acquisition unit of the control device 20 is the cooling operation mode, as described above, the first temperature adjustment unit 34 operates as the first evaporator 34a, the second temperature adjustment unit 38 operates as the second evaporator 38a, and the outdoor unit temperature adjustment unit 39 operates as the outdoor condenser 39b.

[0040] When the operation mode acquired by the operation mode acquisition unit of the control device 20 is the cooling operation mode, if the temperature of the supply air flow 3 is equal to or higher than the temperature of the indoor air, the control device 20 selects the open state of the return air inlet 60, and if the temperature of the supply air flow 3 is lower than the temperature of the indoor air, the control device 20 selects the closed state of the return air inlet 60. The control device 20 transmits the selection result to the return air intake switching unit 64.

[0041] Based on the selection result received from the control device 20, the return air intake switching unit 64 selects the open state or the closed state of the return air inlet 60. That is, when the temperature of the supply air flow 3 is equal to or higher than the temperature of the indoor air, the return air intake switching unit 64 opens the return air inlet 60. Thereby, the return air flow 4 flows through the second heat exchanger 35. On the other hand, when the temperature of the supply air flow 3 is lower than the temperature of the indoor air, the return air intake switching unit 64 closes the return air inlet 60. Thereby, the return air flow 4 does not flow through the second heat exchanger 35.

[0042] The control device 20 may determine the opening degree of the return air suction switching unit 64, for example, to be 0.5 according to the temperature of the supply air flow 3 and the indoor temperature. The return air outlet 62 may adjust the opening degree of the return air suction port 60 based on the opening degree information received from the control device 20.

[0043] In this way, the return air suction switching unit 64 switches the opening and closing of the return air suction port 60 based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow 3 acquired by the supply air flow temperature sensor 50, and the temperature of the indoor air acquired by the indoor temperature sensor 52.

[0044] The supply air flow 3 sucked from the supply air suction port 17 is cooled (pre-cooled) by heat exchange with the exhaust air flow 2 in the first heat exchanger 12. The supply air flow 3 from the first heat exchanger 12 is cooled by the first evaporator 34a. When the temperature of the supply air flow 3 is equal to or higher than the indoor temperature, the supply air flow 3 from the first evaporator 34a performs heat exchange with the return air flow 4 in the second heat exchanger 35. Thereby, the supply air flow 3 is cooled. On the other hand, when the temperature of the supply air flow 3 is lower than the indoor temperature, no heat exchange occurs in the second heat exchanger 35. Further, the supply air flow 3 is cooled by the second evaporator 38a.

[0045] The exhaust air flow 2 sucked from the exhaust air suction port 14 performs heat exchange with the supply air flow 3 in the first heat exchanger 12. Thereby, the exhaust air flow 2 is heated. When the temperature of the supply air flow 3 is equal to or higher than the indoor temperature, the return air flow 4 sucked from the return air suction port 60 performs heat exchange with the supply air flow 3 in the second heat exchanger 35, and the return air flow 4 that has undergone heat exchange is returned to the indoor from the return air outlet 62. On the other hand, when the temperature of the supply air flow 3 is lower than the indoor temperature, the return air flow 4 is not sucked from the return air suction port 60. Since the supply air flow 3 is cooled using the return air flow 4 in this way, the cooling efficiency is improved.

[0046] Next, the case where the heat exchange ventilation device 1 operates in the heating operation mode among a plurality of operation modes will be described. FIGS. 3(a)-(b) show the configuration and operation outline of the heating operation mode in the heat exchange ventilation device 1. FIG. 3(a) shows the configuration of the heat exchange ventilation device 1. When the set operation mode is the heating operation mode, in the refrigeration cycle 30, the refrigerant circulates in the order of the compressor 31, the four-way valve 41, the first temperature adjustment unit 34, the second expander 33b, the second temperature adjustment unit 38, the first expander 33a, the outdoor unit temperature adjustment unit 39, the four-way valve 41, and the compressor 31. In the case of the heating operation mode, the first expander 33a is in an expanded state for reducing the pressure of the refrigerant, and the second expander 33b is in an open state for not reducing the pressure of the refrigerant.

[0047] Here, the outdoor unit temperature adjustment unit 39 functions as an evaporator (outdoor evaporator 39a) when the refrigerant expanded by the first expander 33a is introduced. Also, the first temperature adjustment unit 34 functions as a condenser (first condenser 34b) when the refrigerant compressed by the compressor 31 is introduced. Further, the second temperature adjustment unit 38 also functions as a condenser (second condenser 38b) when the refrigerant compressed by the compressor 31 is introduced.

[0048] As a result, the configuration inside the main body case 11 is shown as in FIG. 3(b). FIG. 3(b) shows the operation outline of the heating operation mode in the heat exchange ventilation device 1. The first heat exchanger 12, the first condenser 34b, the second heat exchanger 35, and the second condenser 38b are arranged in order. The supply air duct 7 is connected from the supply air suction port 17 to the supply air blowout port 18 via the first heat exchanger 12, the first condenser 34b, the second heat exchanger 35, and the second condenser 38b. Also, the exhaust air duct 6 is connected from the exhaust air suction port 14 to the exhaust air blowout port 15 via the first heat exchanger 12. Further, the return air duct 8 is connected from the return air suction port 60 to the return air blowout port 62 via the second heat exchanger 35.

[0049] The control device 20 receives the temperature of the supply air flow 3 from the supply air flow temperature sensor 50 and the indoor temperature from the indoor temperature sensor 52. Further, when the operation mode acquired by the operation mode acquisition unit is the heating operation mode, as described above, the first temperature adjustment unit 34 operates as the first condenser 34b, the second temperature adjustment unit 38 operates as the second condenser 38b, and the outdoor unit temperature adjustment unit 39 operates as the outdoor evaporator 39a.

[0050] When the operation mode acquired by the operation mode acquisition unit of the control device 20 is the heating operation mode, if the temperature of the supply air flow 3 is equal to or higher than the temperature of the indoor air, the closed state of the return air inlet 60 is selected, and if the temperature of the supply air flow 3 is lower than the temperature of the indoor air, the open state of the return air inlet 60 is selected. The control device 20 transmits the selection result to the return air intake switching unit 64.

[0051] The return air intake switching unit 64 selects the open state or the closed state of the return air inlet 60 based on the selection result received from the control device 20. That is, when the temperature of the supply air flow 3 is equal to or higher than the temperature of the indoor air, the return air intake switching unit 64 closes the return air inlet 60. As a result, the return air flow 4 does not flow through the second heat exchanger 35. On the other hand, when the temperature of the supply air flow 3 is lower than the temperature of the indoor air, the return air intake switching unit 64 opens the return air inlet 60. As a result, the return air flow 4 flows through the second heat exchanger 35.

[0052] The control device 20 may determine the opening degree of the return air intake switching unit 64, for example, to be 0.5 according to the temperature of the supply air flow 3 and the indoor temperature. The return air outlet 62 may adjust the opening degree of the return air inlet 60 based on the opening degree information received from the control device 20.

[0053] In this way, the return air intake switching unit 64 switches the opening and closing of the return air inlet 60 based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow 3 acquired by the supply air flow temperature sensor 50, and the temperature of the indoor air acquired by the indoor temperature sensor 52.

[0054] The supply air flow 3 sucked in from the supply air inlet 17 is heated by heat exchange with the exhaust air flow 2 in the first heat exchanger 12. The supply air flow 3 from the first heat exchanger 12 is heated by the first condenser 34b. When the temperature of the supply air flow 3 is equal to or higher than the indoor temperature, no heat exchange occurs in the second heat exchanger 35. On the other hand, when the temperature of the supply air flow 3 is lower than the indoor temperature, the supply air flow 3 from the first evaporator 34a undergoes heat exchange with the return air flow 4 in the second heat exchanger 35. Thereby, the supply air flow 3 is heated. Further, the supply air flow 3 is heated by the second condenser 38b.

[0055] The exhaust air flow 2 sucked in from the exhaust air inlet 14 undergoes heat exchange with the supply air flow 3 in the first heat exchanger 12. Thereby, the exhaust air flow 2 is cooled. When the temperature of the supply air flow 3 is equal to or higher than the indoor temperature, the return air flow 4 is not sucked in from the return air inlet 60. On the other hand, when the temperature of the supply air flow 3 is lower than the indoor temperature, the return air flow 4 sucked in from the return air inlet 60 undergoes heat exchange with the supply air flow 3 in the second heat exchanger 35, and the return air flow 4 that has undergone heat exchange is returned indoors from the return air outlet 62. Since the supply air flow 3 is heated using the return air flow 4 in this way, the heating efficiency is improved.

[0056] Figure 4 is a flowchart showing the operation procedure by the heat exchange ventilation device 1. The operation of the heat exchange ventilation device 1 is started (S10). The operation mode acquisition unit acquires the operation mode (S12). When the operation mode is the dehumidification operation mode (Y in S14), the return air suction switching unit 64 opens the return air inlet 60 (S16). When the operation mode is not the dehumidification operation mode (N in S14) and is the cooling operation mode (Y in S18), if the temperature of the supply air flow 3 is not equal to or higher than the indoor temperature (N in S20), the return air suction switching unit 64 closes the return air inlet 60 (S22). If the temperature of the supply air flow 3 is equal to or higher than the indoor temperature (Y in S20), the return air suction switching unit 64 opens the return air inlet 60 (S24).

[0057] When not in the cooling operation mode (N in S18), if the temperature of the supply air flow 3 is not lower than the indoor temperature (N in S26), the return air suction switching unit 64 closes the return air suction port 60 (S28). If the temperature of the supply air flow 3 is lower than the indoor temperature (Y in S26), the return air suction switching unit 64 opens the return air suction port 60 (S30).

[0058] (Modification Example 1) Modification Example 1 of the present embodiment will be described. In the previous FIGS. 1(b), 2(b), and 3(b), by controlling the inflow of the return air flow 4 into the return air duct 8 by the return air suction switching unit 64, it is controlled whether heat exchange is performed between the supply air flow 3 and the supply air duct 7. On the other hand, in Modification Example 1, the return air duct 8 includes a heat exchange return air duct 72 and a bypass return air duct 74, and by switching between the heat exchange return air duct 72 and the bypass return air duct 74, it is controlled whether heat exchange is performed between the supply air flow 3 and the supply air duct 7.

[0059] FIGS. 5(a)-(c) show an overview of the operation of the heat exchange ventilation device 1. FIG. 5(a) shows the case of the dehumidifying operation mode. Similar to the previous cases, the first heat exchanger 12, the first evaporator 34a, the second heat exchanger 35, and the second condenser 38b are arranged in order. The supply air duct 7 is connected from the supply air suction port 17 to the supply air outlet 18 via the first heat exchanger 12, the first evaporator 34a, the second heat exchanger 35, and the second condenser 38b. Also, the exhaust air duct 6 is connected from the exhaust air suction port 14 to the exhaust air outlet 15 via the first heat exchanger 12.

[0060] A return air duct switching unit 70 is provided in the return air duct 8 from the return air outlet 62 at a position before passing through the second heat exchanger 35. The return air duct 8 branches into a heat exchange return air duct 72 and a bypass return air duct 74 at the return air duct switching unit 70. The heat exchange return air duct 72 is a duct for the return air flow 4 to pass through the second heat exchanger 35, and the bypass return air duct 74 is a duct for the return air flow 4 to bypass the second heat exchanger 35. Further, the heat exchange return air duct 72 and the bypass return air duct 74 are connected at a position after passing through the second heat exchanger 35.

[0061] When the operation mode acquired by the operation mode acquisition unit is the dehumidification operation mode, the control device 20 selects the heat recovery air duct 72 and does not select the bypass return air duct 74 regardless of the detection results of the supply air temperature sensor 50 and the indoor temperature sensor 52. The control device 20 transmits the selection result to the return air duct switching unit 70. The return air duct switching unit 70 has a communication function and selects the heat recovery air duct 72 based on the selection result received from the control device 20, and conveys the return air flow 4 to the heat recovery air duct 72. In this way, the return air duct switching unit 70 switches between the heat recovery air duct 72 and the bypass return air duct 74 based on the operation mode acquired by the operation mode acquisition unit.

[0062] Since the supply air flow 3 sucked from the supply air inlet 17, the exhaust air flow 2 sucked from the exhaust air inlet 14, and the return air flow 4 sucked from the return air inlet 60 are conveyed as before, the description is omitted here.

[0063] Figure 5(b) shows the case of the cooling operation mode. As before, the first heat exchanger 12, the first evaporator 34a, the second heat exchanger 35, and the second evaporator 38a are arranged in order. The supply air duct 7 is connected from the supply air inlet 17 to the supply air outlet 18 via the first heat exchanger 12, the first evaporator 34a, the second heat exchanger 35, and the second evaporator 38a. Also, the exhaust air duct 6 is connected from the exhaust air inlet 14 to the exhaust air outlet 15 via the first heat exchanger 12.

[0064] When the operation mode acquired by the operation mode acquisition unit is the cooling operation mode, if the temperature of the supply air flow 3 is equal to or higher than the temperature of the indoor air, the control device 20 selects the heat recovery air duct 72. On the other hand, when the operation mode acquired by the operation mode acquisition unit is the cooling operation mode, if the temperature of the supply air flow 3 is lower than the temperature of the indoor air, the control device 20 selects the bypass return air duct 74. The control device 20 transmits the selection result to the return air duct switching unit 70.

[0065] The return air passage switching unit 70 switches between the heat return air passage 72 and the bypass return air passage 74 based on the selection result received from the control device 20. That is, when the temperature of the supply air flow 3 is equal to or higher than the temperature of the indoor air, the heat return air passage 72 is opened and the bypass return air passage 74 is closed. Thereby, the return air flow 4 is conveyed through the heat return air passage 72. On the other hand, when the temperature of the supply air flow 3 is lower than the temperature of the indoor air, the heat return air passage 72 is closed and the bypass return air passage 74 is opened. Thereby, the return air flow 4 is conveyed through the bypass return air passage 74.

[0066] In this way, the return air passage switching unit 70 switches between the heat return air passage 72 and the bypass return air passage 74 based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow 3 acquired by the supply air temperature sensor 50, and the temperature of the indoor air acquired by the indoor temperature sensor 52.

[0067] The supply air flow 3 sucked from the supply air inlet 17 and the exhaust air flow 2 sucked from the exhaust air inlet 14 are conveyed in the same manner as before, so the description thereof is omitted here. When the temperature of the supply air flow 3 is equal to or higher than the indoor temperature, the return air flow 4 sucked from the return air inlet 60 passes through the heat return air passage 72 and exchanges heat with the supply air flow 3 in the second heat exchanger 35. The return air flow 4 that has undergone heat exchange is returned indoors from the return air outlet 62. On the other hand, when the temperature of the supply air flow 3 is lower than the indoor temperature, the return air flow 4 sucked from the return air inlet 60 passes through the bypass return air passage 74 and does not exchange heat with the supply air flow 3 in the second heat exchanger 35. The return air flow 4 that has not undergone heat exchange is returned indoors from the return air outlet 62.

[0068] FIG. 5(c) shows the case of the heating operation mode. As before, the first heat exchanger 12, the first condenser 34b, the second heat exchanger 35, and the second condenser 38b are arranged in order. The supply air passage 7 is connected from the supply air inlet 17 to the supply air outlet 18 via the first heat exchanger 12, the first condenser 34b, the second heat exchanger 35, and the second condenser 38b. Also, the exhaust air passage 6 is connected from the exhaust air inlet 14 to the exhaust air outlet 15 via the first heat exchanger 12.

[0069] When the operation mode acquired by the operation mode acquisition unit is the heating operation mode, if the temperature of the supply air flow 3 is equal to or higher than the temperature of the indoor air, the control device 20 selects the bypass return air duct 74. On the other hand, when the operation mode acquired by the operation mode acquisition unit is the heating operation mode and the temperature of the supply air flow 3 is lower than the temperature of the indoor air, the control device 20 selects the heat exchange return air duct 72. The control device 20 transmits the selection result to the return air duct switching unit 70.

[0070] Based on the selection result received from the control device 20, the return air duct switching unit 70 switches between the heat exchange return air duct 72 and the bypass return air duct 74. That is, when the temperature of the supply air flow 3 is equal to or higher than the temperature of the indoor air, the return air duct switching unit 70 opens the bypass return air duct 74 and closes the heat exchange return air duct 72. Thereby, the return air flow 4 is conveyed to the bypass return air duct 74. On the other hand, when the temperature of the supply air flow 3 is lower than the temperature of the indoor air, the bypass return air duct 74 is closed and the heat exchange return air duct 72 is opened. Thereby, the return air flow 4 is conveyed to the heat exchange return air duct 72.

[0071] In this way, the return air duct switching unit 70 switches between the heat exchange return air duct 72 and the bypass return air duct 74 based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow 3 acquired by the supply air temperature sensor 50, and the temperature of the indoor air acquired by the indoor temperature sensor 52.

[0072] Since the supply air flow 3 sucked from the supply air inlet 17 and the exhaust air flow 2 sucked from the exhaust air inlet 14 are conveyed as before, the description is omitted here. When the temperature of the supply air flow 3 is lower than the indoor temperature, the return air flow 4 sucked from the return air inlet 60 passes through the heat exchange return air duct 72 and exchanges heat with the supply air flow 3 in the second heat exchanger 35. The return air flow 4 that has undergone heat exchange is returned indoors from the return air outlet 62. On the other hand, when the temperature of the supply air flow 3 is equal to or higher than the indoor temperature, the return air flow 4 sucked from the return air inlet 60 passes through the bypass return air duct 74 and does not exchange heat with the supply air flow 3 in the second heat exchanger 35. The return air flow 4 that has not undergone heat exchange is returned indoors from the return air outlet 62.

[0073] FIG. 6 is a flowchart showing an operation procedure by the heat exchange ventilation device 1. The operation of the heat exchange ventilation device 1 is started (S50). The operation mode acquisition unit acquires the operation mode (S52). When the operation mode is the dehumidification operation mode (Y in S54), the return air flow 4 is conveyed in the heat exchange return air duct 72 (S56). When the operation mode is not the dehumidification operation mode (N in S54) and is the cooling operation mode (Y in S58), if the temperature of the supply air flow 3 is not equal to or higher than the indoor temperature (N in S60), the return air flow 4 is conveyed in the bypass return air duct 74 (S62). If the temperature of the supply air flow 3 is equal to or higher than the indoor temperature (Y in S60), the return air flow 4 is conveyed in the heat exchange return air duct 72 (S64).

[0074] When it is not the cooling operation mode (N in S58), if the temperature of the supply air flow 3 is not lower than the indoor temperature (N in S66), the return air flow 4 is conveyed in the bypass return air duct 74 (S68). If the temperature of the supply air flow 3 is lower than the indoor temperature (Y in S66), the return air flow 4 is conveyed in the heat exchange return air duct 72 (S70).

[0075] (Modification Example 2) A modification example 2 of this embodiment will be described. In the second embodiment, the exhaust air duct 6 and the return air duct 8 communicate with each other via the confluence duct 80. FIG. 7 shows an outline of the operation of the heat exchange ventilation device 1. Here, as an example, the dehumidification operation mode is shown. Similar to the above, the first heat exchanger 12, the first evaporator 34a, the second heat exchanger 35, and the second condenser 38b are arranged in order. The supply air duct 7 is connected from the supply air inlet 17 to the supply air outlet 18 via the first heat exchanger 12, the first evaporator 34a, the second heat exchanger 35, and the second condenser 38b.

[0076] After passing through the second heat exchanger 35 at the return air inlet 60, the combined air passage 80 branches off from the branch position 82. The combined air passage 80 is connected to the exhaust air passage 6 at the merging position 84. The merging position 84 is the position before passing through the first heat exchanger 12 in the exhaust air passage 6. That is, the combined air passage 80 communicates the exhaust air passage 6 and the return air passage 8 to merge the return air flow 4 after passing through the second heat exchanger 35 into the exhaust air flow 2 before passing through the first heat exchanger 12. When a part of the return air flow 4 cooled in the second heat exchanger 35 merges into the exhaust air flow 2, the temperature of the exhaust air flow 2 decreases, and the temperature difference between the exhaust air flow 2 and the supply air flow 3 in the first heat exchanger 12 increases, so the heat exchange amount increases. As a result, the temperature of the supply air flow 3 flowing into the first evaporator 34a becomes lower, and the dehumidification efficiency is improved.

[0077] The main body of the device, system, or method in the present disclosure includes a computer. By executing a program on this computer, the functions of the main body of the device, system, or method in the present disclosure are realized. The computer mainly includes a processor that operates according to the program as a hardware configuration. The type of the processor is not limited as long as it can realize functions by executing the program. The processor is composed of one or more electronic circuits including a semiconductor integrated circuit (IC) or LSI (Large Scale Integration). The plurality of electronic circuits may be integrated on one chip or provided on a plurality of chips. The plurality of chips may be integrated into one device or provided in a plurality of devices. The program is recorded on a non-temporary recording medium such as a computer-readable ROM, optical disk, or hard disk drive. The program may be pre-stored in the recording medium or supplied to the recording medium via a wide area communication network including the Internet or the like.

[0078] According to this embodiment, since heat exchange is performed between the supply air flow 3 and the exhaust air flow 2 in the first heat exchanger 12 and heat exchange is performed between the supply air flow 3 and the return air flow 4 in the second heat exchanger 35, the efficiency of each operation of the plurality of types of operation modes provided in the heat exchange and ventilation device 1 can be improved. Further, when the operation mode is the dehumidifying operation mode, the return air suction port 60 is opened regardless of the detection results of the supply air temperature sensor 50 and the indoor temperature sensor 52, so that heat exchange can be performed between the supply air flow 3 and the return air flow 4 in the second heat exchanger 35. Further, since heat exchange is performed between the supply air flow 3 and the return air flow 4 in the second heat exchanger 35, the return air flow 4 can be dehumidified. Further, since the return air flow 4 is dehumidified, the dehumidifying efficiency can be improved.

[0079] Further, when the operation mode is the cooling operation mode and the temperature of the supply air flow 3 is equal to or higher than the temperature of the indoor air, the return air suction port 60 is opened, so that the supply air flow 3 can be cooled by heat exchange in the second heat exchanger 35. Further, since the supply air flow 3 is cooled by heat exchange in the second heat exchanger 35, the cooling efficiency can be improved. Further, when the operation mode is the heating operation mode and the temperature of the supply air flow 3 is lower than the temperature of the indoor air, the return air suction port 60 is opened, so that the supply air flow 3 can be heated by heat exchange in the second heat exchanger 35. Further, since the supply air flow 3 is heated by heat exchange in the second heat exchanger 35, the heating efficiency can be improved.

[0080] Further, when the operation mode is the dehumidifying operation mode, the return air flow 4 is conveyed to the heat exchange return air duct 72 regardless of the detection results of the supply air temperature sensor 50 and the indoor temperature sensor 52, so that heat exchange can be performed between the supply air flow 3 and the return air flow 4 in the second heat exchanger 35. Further, when the operation mode is the cooling operation mode and the temperature of the supply air flow 3 is equal to or higher than the temperature of the indoor air, the return air flow 4 is conveyed to the heat exchange return air duct 72, so that the supply air flow 3 can be cooled by heat exchange in the second heat exchanger 35. Further, when the operation mode is the heating operation mode and the temperature of the supply air flow 3 is lower than the temperature of the indoor air, the return air flow 4 is conveyed to the heat exchange return air duct 72, so that the supply air flow 3 can be heated by heat exchange in the second heat exchanger 35.

[0081] In addition, since the return air flow 4 after passing through the second heat exchanger 35 is merged into the exhaust air flow 2 before passing through the first heat exchanger 12, the temperature difference between the supply air flow 3 and the exhaust air flow 2 in the first heat exchanger 12 can be increased. Also, since the temperature difference between the supply air flow 3 and the exhaust air flow 2 in the first heat exchanger 12 is increased, the heat exchange amount in the first heat exchanger 12 can be increased. Further, since the heat exchange amount is increased, the heat exchange efficiency in the heat exchange ventilation device 1 can be improved.

[0082] The summary of one aspect of the present disclosure is as follows. (Item 1) A heat exchange ventilation device (1) having a refrigeration cycle (30) and capable of setting a plurality of operation modes, an operation mode acquisition unit that acquires the operation mode, a housing (11) having a supply air intake (17) for sucking air from the outside, a supply air outlet (18) for blowing air into the room, an exhaust air intake (14) for sucking air from the room, an exhaust air outlet (15) for blowing air to the outside, a return air intake (60) for sucking air from the room, and a return air outlet (62) for blowing air into the room, a supply air duct (7) that communicates the supply air intake (17) and the supply air outlet (18) and conveys a supply air flow (3) that is sucked from the outside and blown into the room through the housing (11), an exhaust air duct (6) that communicates the exhaust air intake (14) and the exhaust air outlet (15) and conveys an exhaust air flow (2) that is sucked from the room and blown to the outside through the housing (11), a return air duct (8) that communicates the return air intake (60) and the return air outlet (62) and conveys a return air flow (4) that is sucked from the room and blown back into the room through the housing (11), a first heat exchanger (12) that performs heat exchange between the supply air flow (3) and the exhaust air flow (2), a first temperature adjustment unit (34) that belongs to the refrigeration cycle (30) and cools or heats the supply air flow (3) after passing through the first heat exchanger (12) based on the operation mode acquired by the operation mode acquisition unit, A second heat exchanger (35) that performs heat exchange between the supply air flow (3) and the return air flow (4) after passing through the first temperature adjustment unit (34); A second temperature adjustment unit (38) that belongs to the refrigeration cycle (30) and cools or heats the supply air flow (3) after passing through the second heat exchanger (35) based on the operation mode acquired by the operation mode acquisition unit; A heat exchange type ventilation device (1) comprising:

[0083] (Item 2) A supply air flow temperature sensor (50) that detects the temperature of the supply air flow (3) after passing through the first temperature adjustment unit (34) and before passing through the second heat exchanger (35); An indoor temperature sensor (52) that detects the temperature of the indoor air; A return air intake switching unit (64) that switches the opening and closing of the return air intake (60) based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow (3) acquired by the supply air flow temperature sensor (50), and the temperature of the indoor air acquired by the indoor temperature sensor (52). The return air intake switching unit (64) is When the operation mode acquired by the operation mode acquisition unit is the dehumidification mode, the return air intake (60) is kept open regardless of the detection results of the supply air flow temperature sensor (50) and the indoor temperature sensor (52). The heat exchange type ventilation device (1) according to Item 1.

[0084] (Item 3) A supply air flow temperature sensor (50) that detects the temperature of the supply air flow (3) after passing through the first temperature adjustment unit (34) and before passing through the second heat exchanger (35); An indoor temperature sensor (52) that detects the temperature of the indoor air; A return air intake switching unit (64) that switches the opening and closing of the return air intake (60) based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow (3) acquired by the supply air flow temperature sensor (50), and the temperature of the indoor air acquired by the indoor temperature sensor (52). The return air intake switching unit (64) is When the operation mode acquired by the operation mode acquisition unit is the cooling mode and the temperature of the supply air flow (3) acquired by the supply air flow temperature sensor (50) is equal to or higher than the temperature of the indoor air acquired by the indoor temperature sensor (52), the return air suction port (60) is opened. When the operation mode acquired by the operation mode acquisition unit is the cooling mode and the temperature of the supply air flow (3) acquired by the supply air flow temperature sensor (50) is lower than the temperature of the indoor air acquired by the indoor temperature sensor (52), the heat exchange type ventilation device (1) according to item 1 closes the return air suction port (60).

[0085] (Item 4) A supply air flow temperature sensor (50) for detecting the temperature of the supply air flow (3) after passing through the first temperature adjustment unit (34) and before passing through the second heat exchanger (35); An indoor temperature sensor (52) for detecting the temperature of the indoor air; A return air suction switching unit (64) for switching the opening and closing of the return air suction port (60) based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow (3) acquired by the supply air flow temperature sensor (50), and the temperature of the indoor air acquired by the indoor temperature sensor (52). The return air suction switching unit (64) When the operation mode acquired by the operation mode acquisition unit is the heating mode and the temperature of the supply air flow (3) acquired by the supply air flow temperature sensor (50) is equal to or higher than the temperature of the indoor air acquired by the indoor temperature sensor (52), the return air suction port (60) is closed. When the operation mode acquired by the operation mode acquisition unit is the heating mode and the temperature of the supply air flow (3) acquired by the supply air flow temperature sensor (50) is lower than the temperature of the indoor air acquired by the indoor temperature sensor (52), the heat exchange type ventilation device (1) according to item 1 opens the return air suction port (60).

[0086] (Item 5) An intake air flow temperature sensor (50) for detecting the temperature of the intake air flow (3) after passing through the first temperature adjustment unit (34) and before passing through the second heat exchanger (35); An indoor temperature sensor (52) for detecting the temperature of the indoor air, and further comprising: The return air duct (8) is A heat exchange return air duct (72) through which the return air flow (4) passes through the second heat exchanger (35); A bypass return air duct (74) through which the return air flow (4) bypasses the second heat exchanger (35); A return air duct switching unit (70) for switching between the heat exchange return air duct (72) and the bypass return air duct (74) based on the operation mode acquired by the operation mode acquisition unit, the temperature of the intake air flow (3) acquired by the intake air flow temperature sensor (50), and the temperature of the indoor air acquired by the indoor temperature sensor (52); The return air duct switching unit (70) is When the operation mode acquired by the operation mode acquisition unit is the dehumidification mode, the return air flow (4) is conveyed to the heat exchange return air duct (72) regardless of the detection results of the intake air flow temperature sensor (50) and the indoor temperature sensor (52). The heat exchange type ventilation device (1) according to item 1.

[0087] (Item 6) An intake air flow temperature sensor (50) for detecting the temperature of the intake air flow (3) after passing through the first temperature adjustment unit (34) and before passing through the second heat exchanger (35); An indoor temperature sensor (52) for detecting the temperature of the indoor air, and further comprising: The return air duct (8) is A heat exchange return air duct (72) through which the return air flow (4) passes through the second heat exchanger (35); A bypass return air duct (74) through which the return air flow (4) bypasses the second heat exchanger (35); A return air duct switching unit (70) that switches the heat recovery air duct (72) and the bypass return air duct (74) based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow (3) acquired by the supply air flow temperature sensor (50), and the temperature of the indoor air acquired by the indoor temperature sensor (52). The return air duct switching unit (70) When the operation mode acquired by the operation mode acquisition unit is the cooling mode and the temperature of the supply air flow (3) acquired by the supply air flow temperature sensor (50) is equal to or higher than the temperature of the indoor air acquired by the indoor temperature sensor (52), the return air flow (4) is conveyed through the heat recovery air duct (72). The heat exchange type ventilation device (1) according to item 1, wherein when the operation mode acquired by the operation mode acquisition unit is the cooling mode and the temperature of the supply air flow (3) acquired by the supply air flow temperature sensor (50) is lower than the temperature of the indoor air acquired by the indoor temperature sensor (52), the return air flow (4) is conveyed through the bypass return air duct (74).

[0088] (Item 7) A supply air flow temperature sensor (50) that detects the temperature of the supply air flow (3) after passing through the first temperature adjustment unit (34) and before passing through the second heat exchanger (35). An indoor temperature sensor (52) that detects the temperature of the indoor air, and further includes. The return air duct (8) A heat recovery air duct (72) through which the second heat exchanger (35) passes through the return air flow (4). A bypass return air duct (74) through which the second heat exchanger (35) bypasses the return air flow (4). A return air duct switching unit (70) that switches the heat recovery air duct (72) and the bypass return air duct (74) based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow (3) acquired by the supply air flow temperature sensor (50), and the temperature of the indoor air acquired by the indoor temperature sensor (52). The return air duct switching unit (70) When the operation mode acquired by the operation mode acquisition unit is the heating mode and the temperature of the supply air flow (3) acquired by the supply air flow temperature sensor (50) is equal to or higher than the temperature of the indoor air acquired by the indoor temperature sensor (52), the return air flow (4) is conveyed to the bypass return air duct (74). The heat exchange type ventilation device (1) according to item 1, wherein when the operation mode acquired by the operation mode acquisition unit is the heating mode and the temperature of the supply air flow (3) acquired by the supply air flow temperature sensor (50) is lower than the temperature of the indoor air acquired by the indoor temperature sensor (52), the return air flow (4) is conveyed to the heat exchange return air duct (72).

[0089] (Item 8) The heat exchange type ventilation device (1) according to item 1, further comprising a confluence air duct (80) that communicates the exhaust air duct (6) and the return air duct (8) to confluence the return air flow (4) after passing through the second heat exchanger (35) with the exhaust air flow (2) before passing through the first heat exchanger (12).

[0090] As described above, the present disclosure has been described based on the embodiments. However, it can be easily inferred that the present disclosure is not limited to the above embodiments at all, and various improvements and modifications are possible without departing from the spirit of the present disclosure.

Explanation of reference numerals

[0091] 1 Heat exchange and ventilation device, 2 Exhaust air flow, 3 Supply air flow, 4 Return air flow, 6 Exhaust air duct, 7 Supply air duct, 8 Return air duct, 10 Indoor unit, 11 Main body case, 12 First heat exchanger, 14 Exhaust air inlet, 15 Exhaust air outlet, 17 Supply air inlet, 18 Supply air outlet, 20 Control device, 30 Refrigeration cycle, 31 Compressor, 32 Outdoor unit, 33 Expander, 33a First expander, 33b Second expander, 34 First temperature control section, 34a First evaporator, 34b First condenser, 35 Second heat exchanger, 38 Second temperature control section, 38a Second evaporator, 38b Second condenser, 39 Outdoor unit temperature control section, 39a Outdoor evaporator, 39b Outdoor condenser, 41 Four-way valve, 50 Supply air flow temperature sensor, 52 Indoor temperature sensor, 60 Return air inlet, 62 Return air outlet, 64 Return air inlet switching section, 70 Return air duct switching section, 72 Heat exchange return air duct, 74 Bypass return air duct, 80 Confluence duct, 82 Branch position, 84 Confluence position.

Claims

1. A heat exchange ventilation device having a refrigeration cycle and capable of setting a plurality of operation modes, an operation mode acquisition unit that acquires the operation mode; a housing having an air supply inlet for sucking air from the outside, an air supply outlet for blowing air into the room, an exhaust inlet for sucking air from the room, an exhaust outlet for blowing air to the outside, a return air inlet for sucking air from the room, and a return air outlet for blowing air into the room; an air supply air passage that communicates the air supply inlet and the air supply outlet and conveys an air supply flow that is sucked from the outside, passes through the housing, and is blown into the room; an exhaust air passage that communicates the exhaust inlet and the exhaust outlet and conveys an exhaust flow that is sucked from the room, passes through the housing, and is blown to the outside; a return air passage that communicates the return air inlet and the return air outlet and conveys a return air flow that is sucked from the room, passes through the housing, and is blown back into the room; a first heat exchanger that performs heat exchange between the air supply flow and the exhaust flow; a first temperature adjustment unit that belongs to the refrigeration cycle and cools or heats the air supply flow after passing through the first heat exchanger based on the operation mode acquired by the operation mode acquisition unit; a second heat exchanger that performs heat exchange between the air supply flow after passing through the first temperature adjustment unit and the return air flow; a second temperature adjustment unit that belongs to the refrigeration cycle and cools or heats the air supply flow after passing through the second heat exchanger based on the operation mode acquired by the operation mode acquisition unit; A heat exchange ventilation device comprising:

2. an air supply flow temperature sensor that detects the temperature of the air supply flow after passing through the first temperature adjustment unit and before passing through the second heat exchanger; an indoor temperature sensor that detects the temperature of the air in the room; A return air intake switching unit that switches the opening and closing of the return air intake based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow acquired by the supply air flow temperature sensor, and the temperature of the indoor air acquired by the indoor temperature sensor. The return air intake switching unit When the operation mode acquired by the operation mode acquisition unit is the dehumidification mode, the return air intake is kept open regardless of the detection results of the supply air flow temperature sensor and the indoor temperature sensor. The heat exchange type ventilation device according to claim 1.

3. A supply air flow temperature sensor that detects the temperature of the supply air flow after passing through the first temperature adjustment unit and before passing through the second heat exchanger. An indoor temperature sensor that detects the temperature of the indoor air. A return air intake switching unit that switches the opening and closing of the return air intake based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow acquired by the supply air flow temperature sensor, and the temperature of the indoor air acquired by the indoor temperature sensor. The return air intake switching unit When the operation mode acquired by the operation mode acquisition unit is the cooling mode and the temperature of the supply air flow acquired by the supply air flow temperature sensor is equal to or higher than the temperature of the indoor air acquired by the indoor temperature sensor, the return air intake is kept open. When the operation mode acquired by the operation mode acquisition unit is the cooling mode and the temperature of the supply air flow acquired by the supply air flow temperature sensor is lower than the temperature of the indoor air acquired by the indoor temperature sensor, the return air intake is kept closed. The heat exchange type ventilation device according to claim 1.

4. A supply air flow temperature sensor that detects the temperature of the supply air flow after passing through the first temperature adjustment unit and before passing through the second heat exchanger. An indoor temperature sensor that detects the temperature of the indoor air. A return air intake switching unit that switches the opening and closing of the return air intake based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow acquired by the supply air flow temperature sensor, and the temperature of the indoor air acquired by the indoor temperature sensor; The return air intake switching unit is configured to: When the operation mode acquired by the operation mode acquisition unit is the heating mode and the temperature of the supply air flow acquired by the supply air flow temperature sensor is equal to or higher than the temperature of the indoor air acquired by the indoor temperature sensor, the return air intake is closed. When the operation mode acquired by the operation mode acquisition unit is the heating mode and the temperature of the supply air flow acquired by the supply air flow temperature sensor is lower than the temperature of the indoor air acquired by the indoor temperature sensor, the return air intake is opened. The heat exchange type ventilation device according to claim 1.

5. A supply air flow temperature sensor that detects the temperature of the supply air flow after passing through the first temperature adjustment unit and before passing through the second heat exchanger; An indoor temperature sensor that detects the temperature of the indoor air; and further includes: The return air duct is configured to: A heat return air duct through which the return air flow passes through the second heat exchanger; A bypass return air duct through which the return air flow bypasses the second heat exchanger; A return air duct switching unit that switches between the heat return air duct and the bypass return air duct based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow acquired by the supply air flow temperature sensor, and the temperature of the indoor air acquired by the indoor temperature sensor; The return air duct switching unit is configured to: When the operation mode acquired by the operation mode acquisition unit is the dehumidification mode, regardless of the detection results of the supply air flow temperature sensor and the indoor temperature sensor, the return air flow is conveyed to the heat return air duct. The heat exchange type ventilation device according to claim 1.

6. A supply air flow temperature sensor that detects the temperature of the supply air flow after passing through the first temperature adjustment unit and before passing through the second heat exchanger; further comprising an indoor temperature sensor configured to detect the temperature of the indoor air; The return air duct includes: a heat exchange return air duct through which the return air flow passes through the second heat exchanger; a bypass return air duct through which the return air flow bypasses the second heat exchanger; a return air duct switching unit configured to switch between the heat exchange return air duct and the bypass return air duct based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow acquired by the supply air flow temperature sensor, and the temperature of the indoor air acquired by the indoor temperature sensor; The return air duct switching unit: when the operation mode acquired by the operation mode acquisition unit is the cooling mode and the temperature of the supply air flow acquired by the supply air flow temperature sensor is equal to or higher than the temperature of the indoor air acquired by the indoor temperature sensor, conveys the return air flow through the heat exchange return air duct; when the operation mode acquired by the operation mode acquisition unit is the cooling mode and the temperature of the supply air flow acquired by the supply air flow temperature sensor is lower than the temperature of the indoor air acquired by the indoor temperature sensor, conveys the return air flow through the bypass return air duct. The heat exchange type ventilation device according to claim 1.

7. further comprising a supply air flow temperature sensor configured to detect the temperature of the supply air flow after passing through the first temperature adjustment unit and before passing through the second heat exchanger; an indoor temperature sensor configured to detect the temperature of the indoor air; The return air duct includes: a heat exchange return air duct through which the second heat exchanger passes through the return air flow; a bypass return air duct through which the second heat exchanger bypasses the return air flow; a return air duct switching unit configured to switch between the heat exchange return air duct and the bypass return air duct based on the operation mode acquired by the operation mode acquisition unit, the temperature of the supply air flow acquired by the supply air flow temperature sensor, and the temperature of the indoor air acquired by the indoor temperature sensor; The return air duct switching unit: When the operation mode acquired by the operation mode acquisition unit is the heating mode and the temperature of the supply air flow acquired by the supply air flow temperature sensor is equal to or higher than the temperature of the indoor air acquired by the indoor temperature sensor, the return air flow is conveyed through the bypass return air duct. The heat exchange type ventilation device according to claim 1, wherein when the operation mode acquired by the operation mode acquisition unit is the heating mode and the temperature of the supply air flow acquired by the supply air flow temperature sensor is lower than the temperature of the indoor air acquired by the indoor temperature sensor, the return air flow is conveyed through the heat exchange return air duct.

8. The heat exchange type ventilation device according to claim 1, further comprising a confluence air duct that communicates the exhaust air duct and the return air duct to cause the return air flow after passing through the second heat exchanger to merge with the exhaust air flow before passing through the first heat exchanger.

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