US20240133576A1

US20240133576A1 - Refrigeration cycle apparatus and indoor unit

Info

Publication number: US20240133576A1
Application number: US18/546,499
Authority: US
Inventors: Shinya Higashiiue
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2021-04-22
Filing date: 2021-04-21
Publication date: 2024-04-25
Also published as: EP4328512A4; JPWO2022224406A1; EP4328512A1; CN117157493A; JP7466764B2; WO2022224406A1

Abstract

A refrigeration cycle apparatus includes an indoor unit provided with a first air inlet and a second air inlet; a first heat exchange unit located in a first air flow passage connecting the first air inlet and an air outlet; a second heat exchange unit located in a second air flow passage connecting the second air inlet and the air outlet, the second heat exchange unit being connected to the first heat exchange unit such that the second heat exchange unit is positioned downstream of the first heat exchange unit during heating operation; a first damper capable of adjusting an amount of air entering from the first air flow passage to the second air flow passage; and a second damper provided at the second air inlet and capable of adjusting an amount of air to be sucked from the second air inlet.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a U.S. National Stage Application of International Application No. PCT/JP2021/016303 filed on Apr. 22, 2021, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a refrigeration cycle apparatus and an indoor unit.

BACKGROUND

Some refrigeration cycle apparatus cools or heats air by exchanging heat between the room air and refrigerant flowing in a heat exchanger. In recent years, there is a refrigeration cycle apparatus with a technique to draw outside air into an indoor unit and perform cooling and heating while providing ventilation. (See, for example, Patent Literature 1)

PATENT LITERATURE

- Patent Literature 1: Japanese Unexamined Patent Application Publication No. H11-257793

However, in the refrigeration cycle apparatus disclosed in Patent Literature 1, the indoor unit is provided with a heat exchanger dedicated to ventilation. This limits the size of a heat exchanger that can be used to perform cooling and heating without providing ventilation, and thus may decrease efficiency of the refrigeration cycle apparatus.

SUMMARY

The present disclosure has been made to solve the problem described above. It is an object of the present disclosure to provide a refrigeration cycle apparatus that performs cooling and heating, in which it is possible to set whether to provide ventilation and it is also possible to prevent a decrease in efficiency when the refrigeration cycle apparatus does not provide ventilation.
A refrigeration cycle apparatus according to an embodiment of the present disclosure includes an indoor unit provided with a first air inlet communicating with an inside of a room and a second air inlet communicating with outside of the room; a first heat exchange unit located in a first air flow passage connecting the first air inlet and an air outlet; a second heat exchange unit located in a second air flow passage connecting the second air inlet and the air outlet, the second heat exchange unit being connected to the first heat exchange unit such that the second heat exchange unit is positioned downstream of the first heat exchange unit when the refrigeration cycle apparatus performs heating operation; a first damper capable of adjusting an amount of air entering from the first air flow passage to the second air flow passage; and a second damper provided at the second air inlet and capable of adjusting an amount of air to be sucked from the second air inlet.
In the refrigeration cycle apparatus according to an embodiment of the present disclosure, it is possible to set whether to provide ventilation. Even when not providing ventilation, the refrigeration cycle apparatus can still exhibit equal performance compared to an indoor heat exchanger installed in some refrigeration cycle apparatus. This can prevent the refrigeration cycle apparatus from decreasing its efficiency regardless of the usage conditions.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates the configuration of a refrigeration cycle apparatus in Embodiment 1.

FIG. 2 illustrate operation of an indoor unit in Embodiment 1.

FIG. 3 illustrates the state in an indoor heat exchanger during heating operation in Embodiment 1.

FIG. 4 illustrates another configuration of the indoor unit in Embodiment 1.

FIG. 5 illustrate the structure and operation of, and a flow of air in, an indoor unit in Working Example 1.

FIG. 6 illustrate the structure and operation of, and a flow of air in, an indoor unit in Working Example 2.

FIG. 7 illustrate the structure and operation of, and a flow of air in, an indoor unit in Working Example 3.

FIG. 8 illustrate an operating means of a second damper in Working Example 3.

FIG. 9 illustrate a modification of the indoor unit in Working Example 1.

FIG. 10 illustrate a modification of the indoor unit in Working Example 2.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described below with reference to the accompanying drawings. In the drawings, the same or equivalent parts will be denoted by the same reference signs, and redundant descriptions of the same or equivalent parts will be appropriately simplified or omitted. Note that the embodiments described below are not intended to limit the scope of the present disclosure.

Embodiment 1

FIG. 1 illustrates the configuration of a refrigeration cycle apparatus 100 in the present embodiment. The refrigeration cycle apparatus 100 includes a compressor 1, a four-way valve 2, an indoor unit 3, an expansion valve 9, and an outdoor heat exchanger 10. Further in FIG. 1 , the indoor unit 3 has a first indoor heat exchange unit 4, a second indoor heat exchange unit 5, and a first indoor fan 6 accommodated in the indoor unit 3. Note that the outdoor heat exchanger 10 is accommodated in an outdoor unit (not illustrated) and an outdoor fan is also accommodated in the outdoor unit.
Furthermore, the refrigeration cycle apparatus 100 includes a controller 50. The controller 50 issues a command to the compressor 1, the four-way valve 2, the first indoor fan 6, the expansion valve 9, a first damper 11, and a second damper 12, which will be described later, and the outdoor fan (not illustrated), to control operation of the respective components.
The compressor 1, the four-way valve 2, the first indoor heat exchange unit 4, the second indoor heat exchange unit 5, the expansion valve 9, and the outdoor heat exchanger 10 are connected by pipes, forming a refrigerant circuit. In the refrigerant circuit, refrigerant such as R32 (difluoromethane) circulates. Note that the type of refrigerant to be filled in the refrigeration cycle apparatus 100 is not particularly limited.
In FIG. 1 , in cooling operation, refrigerant flows in the direction shown by the dotted arrows. That is, refrigerant discharged from the compressor 1 condenses in the outdoor heat exchanger 10, is reduced in pressure by the expansion valve 9, and evaporates in the second indoor heat exchange unit 5 and the first indoor heat exchange unit 4. The refrigerant having evaporated flows back to the compressor 1.
In contrast, in heating operation, refrigerant flows in the direction shown by the solid arrows. That is, refrigerant discharged from the compressor 1 condenses in the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5, is reduced in pressure by the expansion valve 9, and evaporates in the outdoor heat exchanger 10. The refrigerant having evaporated flows back to the compressor 1. Switching between the cooling operation and the heating operation is performed by the four-way valve 2 changing the connection in the refrigerant circuit.
The compressor 1 is, for example, a rotary compressor. The capacity, rated frequency, and other specifications of the compressor 1 are determined by the type of refrigerant to be filled in the refrigerant circuit, the capacity of the refrigeration cycle apparatus 100, and other factors. Note that the compressor 1 may be a piston compressor or a scroll compressor. The compressor 1 may be operated with a rated frequency by the controller 50 or with a variable frequency controlled by an inverter installed in the controller 50.
The four-way valve 2 is configured to switch flow passages, and switches between flow passages depending on whether the refrigeration cycle apparatus 100 performs cooling operation or heating operation. When the refrigeration cycle apparatus 100 performs cooling operation, the four-way valve 2 connects a discharge port of the compressor 1 and the outdoor heat exchanger 10, and also connects the first indoor heat exchange unit 4 and a suction port of the compressor 1. In contrast, when the refrigeration cycle apparatus 100 performs heating operation, the four-way valve 2 connects the discharge port of the compressor 1 and the first indoor heat exchange unit 4, and also connects the outdoor heat exchanger and the suction port of the compressor 1. The connections in the four-way valve 2 are changed by the controller 50.
The indoor unit 3 accommodates the first indoor heat exchange unit 4, the second indoor heat exchange unit 5, and the first indoor fan 6 in the indoor unit 3. Note that the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5 may be identical indoor heat exchangers to each other, or may be different indoor heat exchangers. There is a structural relationship between the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5, including two points as follows. The first point is that the first indoor heat exchange unit 4 is positioned upstream of the second indoor heat exchange unit 5 in a flow of refrigerant when the refrigeration cycle apparatus 100 performs heating operation, while the second indoor heat exchange unit 5 is positioned downstream of the first indoor heat exchange unit 4 during the heating operation. The second point is that, as will be described later, while room air always flows through the first indoor heat exchange unit 4, outside air or room air flows through the second indoor heat exchange unit 5.
The first indoor heat exchange unit 4 and the second indoor heat exchange unit 5 are each, for example, a fin-and-tube heat exchanger made up of cooper tubes and aluminum fins fixedly attached to the copper tubes. Refrigerant flows through the inside of the copper tubes, and heat of the refrigerant is thus transmitted to the fins. This allows the refrigerant and air flowing between the fins to exchange heat with each other. Note that, in general, in a fin-and-tube heat exchanger, refrigerant flows through the inside of multiple branches of copper tubes (hereinafter, “paths”). The number of branches of copper tubes (hereinafter, “the number of paths”) may be equal or different between the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5. The density and shape of the fins may also be the same or different between the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5. Note that, when the volume of the first indoor heat exchange unit 4 and the volume of the second indoor heat exchange unit 5 are considered, the first indoor heat exchange unit 4 is larger in volume than the second indoor heat exchange unit 5. As will be described later, when the refrigeration cycle apparatus 100 performs heating operation, a relatively large amount of refrigerant in a gas state and in a two-phase gas-liquid state flows through the first indoor heat exchange unit 4, while a relatively large amount of refrigerant in a liquid state flows through the second indoor heat exchange unit 5. In general, refrigerant in a gas state and in a two-phase gas-liquid state fills a larger proportion of the volume of a refrigeration cycle heat exchanger in comparison to refrigerant in a liquid state. Accordingly, the first indoor heat exchange unit 4 needs to have a volume larger than a volume of the second indoor heat exchange unit 5.
The first indoor heat exchange unit 4 and the second indoor heat exchange unit 5 are connected by copper tubes. Note that the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5 may be connected in any manner. For example, provided that the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5 have equal number of paths, their respective paths may be connected to each other. For another example, in a case where the first indoor heat exchange unit 4 has a larger number of paths than the number of paths of the second indoor heat exchange unit 5, some of the paths of the first indoor heat exchange unit 4 may be merged into one that is merged with a path of the second indoor heat exchange unit 5.
The first indoor fan 6 is, for example, a cross flow fan provided inside the indoor unit 3. The first indoor fan 6 generates airflow to help blow out the air with its temperature adjusted by the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5 from the indoor unit 3. The first indoor fan 6 is controlled by the controller 50. Note that the first indoor fan 6 is not limited to the cross flow fan, and any means such as a propeller fan and a sirocco fan may be used as the first indoor fan 6.
A first air inlet 13 through which room air is sucked, a second air inlet 14 through which outside air is sucked, and an air outlet 15 through which air with its temperature adjusted is blown out are formed in the indoor unit 3. For example, outside air is sucked from an air passage hole provided at a wall of a room or from a duct connecting to the outside of the room through the second air inlet 14.
Room air sucked through the first air inlet 13 into the indoor unit 3 passes through the first indoor heat exchange unit 4 and is blown out from the air outlet 15. In contrast, outside air sucked through the second air inlet 14 into the indoor unit 3 passes through the second indoor heat exchange unit 5 and is blown out from the air outlet 15. The room air described above flows through an air flow passage, that is, a path connecting the first air inlet 13 and the air outlet 15. This path is defined as a first air flow passage 7. Similarly, the outside air flows through an air flow passage, that is, a path connecting the second air inlet 14 and the air outlet 15. This path is defined as a second air flow passage 8.
FIGS. 2(a) to 2(d) illustrate the states of the first damper 11 and the second damper 12, and flows of air through the first air flow passage 7 and the second air flow passage 8. The first damper 11 is installed in the first air flow passage 7 at a position at which the first damper 11 is capable of adjusting the amount of room air that branches off from the first air flow passage 7 and flows through the second air flow passage 8. In contrast, the second damper 12 is installed in the vicinity of the second air inlet 14 or another position at which the second damper 12 is capable of adjusting the amount of outside air to be sucked through the second air inlet 14.
An example of the installation position of the first damper 11 is described below in more detail. As illustrated in FIGS. 2(a) and 2(b), a partition wall 18 may be provided inside the indoor unit 3 to separate the first air flow passage 7 from the second air flow passage 8. In this case, there is a hole on a portion of the partition wall 18 to allow the first air flow passage 7 and the second air flow passage 8 to communicate with each other. The first damper 11 is installed at a position at which the first damper 11 is capable of opening and closing the hole. The first damper 11 is installed in this manner, and the first damper 11 thus can prevent the room air flowing through the first air flow passage 7 from flowing to the second indoor heat exchange unit 5, or can adjust the room air described above such that it flows to the second indoor heat exchange unit 5.
Note that the example has been described above in which the partition wall 18 is provided in the indoor unit 3, however, the partition wall 18 may not be necessarily provided as long as a flow of room air can be adjusted by only the first damper 11 without the partition wall 18. The partition wall 18 is provided for the purpose of preventing room air from entering the second indoor heat exchange unit 5 when the first damper 11 is in a closed state. Therefore, the structure of the partition wall 18 is not limited to the example as described above in which the partition wall 18 separates the first air flow passage 7 from the second air flow passage 8 and has a hole on a portion of the partition wall 18 to allow both the air flow passages to communicate with each other.
A flow of air in the indoor unit 3 is described below in more detail. In FIG. 2(a), the first damper 11 is in a closed state, while the second damper 12 is in an open state. In this case, room air sucked through the first air inlet 13 enters the first indoor heat exchange unit 4 from the first air flow passage 7. Outside air sucked through the second air inlet 14 enters the second indoor heat exchange unit 5 from the second air flow passage 8.
In contrast, in FIG. 2(b), the first damper 11 is in an open state, while the second damper 12 is in a closed state. In this case, room air sucked through the first air inlet 13 flows to the first air flow passage 7. Further, since the first damper 11 is in an open state, a portion of the sucked room air branches off from the first air flow passage 7 and then also flows to the second air flow passage 8. In this case, the room air enters both the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5.
In contrast, in FIG. 2(c), the first damper 11 is in a closed state, while the second damper 12 is in a half-open state. In this case, room air sucked through the first air inlet 13 flows to the first air flow passage 7. Outside air sucked through the second air inlet 14 flows to the second air flow passage 8. Note that the second damper 12 is in a half-open sate, and accordingly has a smaller open area of the second air inlet 14 compared to an open area in a case of FIG. 2(a). For this reason, the amount of outside air to be sucked through the second air inlet 14 is reduced compared to the amount of outside air in a case of FIG. 2(a).
In contrast, in FIG. 2(d), the first damper 11 and the second damper 12 are each in a half-open state. In this case, room air sucked through the first air inlet 13 passes through the first air flow passage 7. Note that, since the first damper 11 is in a half-open state, a portion of the sucked room air flows to the second air flow passage 8. Outside air sucked through the second air inlet 14, and the portion of the sucked room air flows to the second air flow passage 8.
The expansion valve 9 is, for example, a solenoid valve with its opening degree controllable. The expansion valve 9 reduces the high pressure of refrigerant having entered the expansion valve 9 to a low pressure. The opening degree of the solenoid valve is controlled by the controller 50.
The outdoor heat exchanger 10 is, for example, a fin-and-tube heat exchanger. While FIG. 1 illustrates the example in which there is a single outdoor heat exchanger 10, the number of paths may be variable or the density and shape of the fins may be variable, for example, in any location throughout the outdoor heat exchanger 10.
The controller 50 is made up of, for example, a central processing unit (CPU), a storage medium having control programs stored in the storage medium, such as a read only memory (ROM), a working memory such as a random access memory (RAM), and a communication circuit. The controller 50 issues a command to the compressor 1, the four-way valve 2, the first indoor fan 6, the expansion valve 9, the first damper 11, the second damper 12, and the outdoor fan in accordance with operational programs stored in advance or signals input by a user of a refrigeration cycle apparatus, and thus controls operation of the respective components.
Subsequently, operation and effects of the refrigeration cycle apparatus 100 in the present embodiment are described. First, heating operation is described, during which the refrigeration cycle apparatus 100 of the present disclosure produces significant effects.
In the descriptions below, the first damper 11 and the second damper 12 operate automatically by detecting the conditions in a room through a sensor and other devices. In this case, the first damper 11 and the second damper 12 are brought into any of the states in FIGS. 2(a) to 2(d) depending on the outside air temperature and the room air temperature, as well as on contamination status of the room air.
Note that the configuration of the refrigeration cycle apparatus 100 in the present disclosure is not limited to this, and the first damper 11 and the second damper 12 may operate in accordance with a signal input through a remote control or other means by a user of the refrigeration cycle apparatus 100, or may be operated manually by the user.
First, circumstances are considered where the outside air temperature is lower than the room air temperature and the room air is contaminated. In this case, as illustrated in FIG. 2(a), the first damper 11 is in a closed state, while the second damper 12 is in an open state. In this case, the room air flows through the first air flow passage 7 and the first indoor heat exchange unit 4, while the outside air flows through the second air flow passage 8 and the second indoor heat exchange unit 5.
In this case, since the outside air is supplied into the room, the level of air contamination in the room is reduced. Note that the contaminated air in the room is discharged to the outside from a window or an air vent provided in the room, or from a crack.
At this time, higher-temperature room air flows through the first indoor heat exchange unit 4, while lower-temperature outside air flows through the second indoor heat exchange unit 5. FIG. 3 illustrates the state in the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5. Note that, in a case of FIG. 3 , the state in the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5 in FIG. 2(a) is illustrated by the solid line. In FIG. 3 , high-temperature and high-pressure gas refrigerant compressed in the compressor 1 enters the first indoor heat exchange unit 4. The high-temperature and high-pressure gas refrigerant exchanges heat with room air and thus becomes two-phase gas-liquid refrigerant. The two-phase gas-liquid refrigerant further exchanges heat with the room air and thus becomes liquid refrigerant.
The refrigerant having become liquid refrigerant enters the second indoor heat exchange unit 5. Since the outside air temperature is lower than the room air temperature, the difference in temperature between the refrigerant and the outside air increases at the second indoor heat exchange unit 5, and accordingly the amount of heat exchange increases. The refrigerant having become subcooled liquid through the heat exchange flows out from the second indoor heat exchange unit 5.
Descriptions are made on differences in the state between the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5 in the present disclosure and an existing indoor heat exchanger of some refrigeration cycle apparatus in which outside air is not drawn into an indoor unit. FIG. 3 shows the state in the existing indoor heat exchanger by the dotted line. In the existing heat exchanger, heat is exchanged between refrigerant and high-temperature room air even in the region where the refrigerant has become liquid. That is, there is a relatively small difference in temperature between the air and the refrigerant, and accordingly the amount of heat exchange decreases.
In this case, to ensure a sufficient amount of heat exchange in the liquid region, the subcooled liquid region in the heat exchanger is enlarged, while the two-phase gas-liquid region in the heat exchanger is reduced. In general, the heat transfer rate in tubes of a heat exchanger is higher in the two-phase gas-liquid region than in the subcooled liquid region. For this reason, in the existing heat exchanger whose subcooled liquid region is relatively large, the efficiency of this existing heat exchanger decreases and its internal pressure increases.
In contrast, the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5 of the present disclosure illustrated by the solid line can still ensure a sufficient amount of heat exchange even in the subcooled liquid region since the second indoor heat exchange unit 5 has a relatively large difference in temperature between refrigerant and outside air. Consequently, the two-phase gas-liquid region in the heat exchanger is larger compared to the existing heat exchanger, and thus the efficiency of the heat exchanger improves. Accordingly, the pressure in the heat exchanger decreases compared to the pressure in a case of the existing heat exchanger. As the pressure in the heat exchanger decreases, the ratio between high-pressure and low-pressure in a refrigeration cycle formed in the refrigeration cycle apparatus 100, that is, the compression ratio in the compressor 1 decreases, which improves efficiency of the compressor 1, and leads to energy saving. Further, as the subcooled liquid region is reduced, the amount of refrigerant to be filled in the refrigeration cycle apparatus 100 decreases in its entirety.
In addition, in the second indoor heat exchange unit 5 where there is a relatively large difference in temperature between refrigerant and outside air, the amount of heat exchange between the refrigerant and the outside air increases, and the temperature of outside air entering the indoor unit thus can be quickly increased. With this configuration, although ventilation is provided by allowing the outside air to enter the room, problems such as a reduction in the heating capacity and a decrease in blowing temperature are less likely to occur.
Next, circumstances are considered where room air is not contaminated. In this case, as illustrated in FIG. 2(b), the second damper 12 is in a closed state, while the first damper 11 is in an open state. In this case, the room air flows to the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5. At this time, the states in the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5 are the same as the states in a case of the existing heat exchanger in which outside air is not drawn into the indoor unit, and therefore descriptions of the states in the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5 are omitted.
Subsequently, a case is described where room air is contaminated at a relatively low level. In this case, as illustrated in FIG. 2(c), the second damper 12 is in a half-open state, while the first damper 11 is in a closed state. In this case, the amount of outside air that flows through the second air flow passage 8 and the second indoor heat exchange unit 5 is smaller compared to the amount of the outside air when the second damper 12 is in an open state illustrated in FIG. 2(a). The reason for this is that the second damper 12 is in a half-open state, which results in an air flow resistance.
In the state illustrated in FIG. 2(c), ventilation is provided in the room more slowly compared to the case illustrated in FIG. 2(a). Also in this case, the difference in temperature between refrigerant and outside air increases at the second indoor heat exchange unit 5, and the efficiency of the heat exchanger thus improves in its entirety as illustrated in FIG. 3 . In addition, since the amount of outside air decreases, problems such as a reduction in heating capacity and a decrease in blowing temperature are even less likely to occur.
Furthermore, when the outside air temperature is higher than the room air temperature, the first damper 11 may be brought into a half-open state as illustrated in FIG. 2(d). In this case, room air sucked through the first air inlet 13 partially enters the second air flow passage 8. In the second air flow passage 8, the room air described above and outside air sucked through the second air inlet 14 are mixed together. At this time, since the room air temperature is lower than the outside air temperature, the mixed air has a temperature lower than the outside air temperature. The mixed air described above enters the second indoor heat exchange unit 5.
In a case where the outside air temperature is relatively high, when the outside air is allowed to enter the second indoor heat exchange unit 5, the difference in temperature between the outside air and refrigerant decreases, and accordingly the amount of heat exchange decreases. However, the room air and the outside air are mixed together as illustrated in FIG. 2(d), and the mixed air with its temperature decreased is thus allowed to enter the second indoor heat exchange unit 5. With this configuration, the refrigeration cycle apparatus 100 can provide ventilation, while preventing a decrease in the amount of heat exchange.
The operation of the refrigeration cycle apparatus 100 has been described above. However, the examples illustrated in FIGS. 2(a) to 2(d) are not intended to limit the operation of the refrigeration cycle apparatus 100. The refrigeration cycle apparatus 100 can also operate differently from the operation illustrated in FIGS. 2(a) to 2(d). For example, both the first damper 11 and the second damper 12 may be each brought into an open state. In this case, even when the outside air temperature is relatively high, it is still possible, in addition to increasing the amount of ventilation, to slow the decrease in the amount of heat exchange in the second indoor heat exchange unit 5.
In FIGS. 2(a) to 2(d), each of the first damper 11 and the second damper 12 is in any of an open state, a closed state, or a half-open state. However, it is still possible for each of the first damper 11 and the second damper 12 to be in an intermediate state between the open state and the half-open state or in an intermediate state between the closed state and the half-open state. The opening degree of each of the first damper 11 and the second damper 12 can be set minutely in the manner as described above, and the refrigeration cycle apparatus 100 thus can adjust the amount of ventilation in response to the circumstances in the room, and can optimize as possible the efficiency of the heat exchanger.
Note that, while the case where the refrigeration cycle apparatus 100 performs heating operation has been described above, the refrigeration cycle apparatus 100 can also perform cooling operation. In this case, circumstances are considered where the outside air temperature is higher than the room air temperature and the room air is contaminated. In this case, as illustrated in FIG. 2(a), the second damper 12 is in an open state, while the first damper 11 is in a closed state, and room air flows through the first indoor heat exchange unit 4, while outside air flows through the second indoor heat exchange unit 5.
At this time, low-temperature refrigerant in a two-phase gas-liquid state with its pressure reduced by the expansion valve 9 flows through the second indoor heat exchange unit 5. As high-temperature outside air enters the second indoor heat exchange unit 5, the difference in temperature between the outside air and the refrigerant increases, and accordingly the amount of heat exchange increases. At this time, the high temperature of the outside air is decreased quickly to a low temperature through the heat exchange. Therefore, the refrigeration cycle apparatus 100 can provide ventilation by supplying the outside air, in addition to preventing the reduction in cooling capacity and the increase in blowing temperature.
During cooling operation, the refrigeration cycle apparatus 100 also changes the states of the first damper 11 and the second damper 12 in response to the contamination status of the room air, and the outside air temperature and the room air temperature. This allows the refrigeration cycle apparatus 100 to provide the proper amount of ventilation, in addition to maintaining its cooling capacity and efficiency under various circumstances.
As explained above, the refrigeration cycle apparatus 100 in the present embodiment operates the first damper 11 and the second damper 12 in response to the contamination status of room air, the outside air temperature, the room air temperature, and other factors. This allows the refrigeration cycle apparatus 100 to provide the proper amount of ventilation, in addition to reducing variations in its blowing temperature.
In a case where the refrigeration cycle apparatus 100 does not provide ventilation, the refrigeration cycle apparatus 100 can feed room air to the second indoor heat exchange unit 5 by operating the first damper 11 and the second damper 12. In this case, the condition of air inside the indoor unit 3, that is, a mechanism to exchange heat between the air and refrigerant is the same as the mechanism to exchange heat between air and refrigerant in an indoor unit of an existing refrigeration cycle apparatus. Therefore, even when it is unnecessary to provide ventilation, the refrigeration cycle apparatus 100 can still achieve efficiency almost equal to efficiency of the existing refrigeration cycle apparatus.
Note that the configuration of the refrigeration cycle apparatus 100 explained above is merely an example of the configuration of the refrigeration cycle apparatus 100 in the present disclosure. Various modifications can be made without departing from the scope of the present disclosure.
FIG. 4 illustrates another configuration example of the indoor unit 3. In FIG. 4 , a second indoor fan 16 is provided. It is thus possible to adjust the amount of outside air that enters the second indoor heat exchange unit 5 independently of the amount of room air that enters the first indoor heat exchange unit 4. In addition, in FIG. 4 , a filter 17 is installed at the second air inlet 14. The filter 17 removes dust and dirt contained in the outside air. This allows cleaner outside air to be supplied into a room.

Working Example 1

Working Examples of the structure and operation of the indoor unit 3 will be described below. Note that a flow of air inside the indoor unit 3 is additionally described.
FIGS. 5(a) to 5(e) illustrate the structure and operation of the indoor unit 3 of the refrigeration cycle apparatus 100 in Working Example 1, and illustrate a flow of air inside the indoor unit 3. FIG. 5(a) is a perspective view illustrating the structure of an indoor unit 3 a in its entirety. FIG. 5(b) is a front view of the indoor unit 3 a, which is viewed from the front. FIG. 5(c) is a rear view of the indoor unit 3 a, which is viewed from the rear. FIGS. 5(d) and 5(e) are left-side views of the indoor unit 3 a, which is viewed from the left.
In the indoor unit 3 a illustrated in FIGS. 5(a) to 5(e), the first air inlet 13 is provided at the top face of the indoor unit 3 a, through which room air is sucked, and a second air inlet 14 a is provided at the rear face of the indoor unit 3 a, through which outside air is sucked. At the lower portion of the front face of the indoor unit 3 a, the air outlet 15 is provided. The air outlet 15 is provided with an air-flow direction adjustment means configured to adjust the direction of airflow blown out from the indoor unit 3 a. Further, the indoor unit 3 a has first indoor heat exchange units 4 a and 4 b, a second indoor heat exchange unit 5 a, and the first indoor fan 6 accommodated in the indoor unit 3 a.
Furthermore, the indoor unit 3 a has a first damper 11 a and a second damper 12 a accommodated in the indoor unit 3 a. The second damper 12 a is located in the vicinity of the second air inlet 14 a. The second damper 12 a has a shape substantially the same as a shape of the second air inlet 14 a. Additionally, the second damper 12 a is slightly larger in size than the second air inlet 14 a. In the example illustrated in FIG. 5(c), the second damper 12 a is located immediately below the second air inlet 14 a. While the second air inlet 14 a has a rectangular shape, the second damper 12 a also has a rectangular shape. The second damper 12 a has a width and a height that are both greater than a width and a height of the second air inlet 14 a.
Furthermore, the second damper 12 a has an operating means (not illustrated) and operates such that the second damper 12 a is brought into any of an open state in which the second damper 12 a does not interfere with outside air flowing from the second air inlet 14 a into the indoor unit 3 a, a closed state in which the second damper 12 a closes the second air inlet 14 a and stops the outside air from entering the indoor unit 3 a, and a half-open state that is intermediate between the open state and the closed state. When the second damper 12 a is in the closed state, since the second damper 12 a is greater in size than the second air inlet 14 a, the second damper 12 a can completely seal the second air inlet 14 a.
Note that, as the operating means configured to change the state of the second damper 12 a, any type of means can be used. For example, a rotational shaft may be attached to one end of the second damper 12 a, and the rotational shaft may be rotated by power to operate the second damper 12 a.
The first damper 11 a is located inside the indoor unit 3 a and between the first air inlet 13 and the second indoor heat exchange unit 5 a. In the example illustrated in FIGS. 5(a) and 5(d), the first damper 11 a is installed in the rear face of the indoor unit 3 a below the first air inlet 13.
While the shape of the first damper 11 a is not particularly limited, the first damper 11 a has a size large enough to stop the room air sucked through the first air inlet 13 from entering the second indoor heat exchange unit 5 a. In the example in FIGS. 5(a) and 5(d), the first damper 11 a has a width greater than a width of the first air inlet 13, and a length greater than the distance from the rear face of the indoor unit 3 a to the second indoor heat exchange unit 5 a. The first damper 11 a has the size as described above, and when the first damper 11 a is in a closed state, which will be described later, the first damper 11 a thus can stop the room air from entering the second indoor heat exchange unit 5 a.
Furthermore, the first damper 11 a has an operating means (not illustrated) and operates such that the first damper 11 a is brought into any of a closed state in which the first damper 11 a stops room air sucked through the first air inlet 13 from entering the second indoor heat exchange unit 5 a, an open state in which the first damper 11 a does not interfere with the room air entering the second indoor heat exchange unit 5 a, and a half-open state that is intermediate between the open state and the closed state. When the first damper 11 a is in the closed state, since the first damper 11 a has the width greater than the width of the first air inlet 13, and the length greater than a length from the rear face of the indoor unit 3 a to the second indoor heat exchange unit 5 a, the first damper 11 a can stop the room air from entering the second indoor heat exchange unit 5 a.
Note that, as the operating means configured to change the state of the first damper 11 a, any type of means can be used. For example, a rotational shaft may be attached to one end of the first damper 11 a, and the rotational shaft may be rotated by power to operate the first damper 11 a.
FIGS. 5(d) and 5(e) illustrate airflow in the indoor unit 3 a when the indoor unit 3 a is viewed from the leftward direction. In FIG. 5(d), the second damper 12 a is in the open state, while the first damper 11 a is in the closed state. In contrast, in FIG. 5(e), the second damper 12 a is in the closed state, while the first damper 11 a is in the open state.
In the state illustrated in FIG. 5(d), the room air enters the indoor unit 3 a from the first air inlet 13, while the outside air enters the indoor unit 3 a from the second air inlet 14 a. Note that the room air sucked through the first air inlet 13 is interfered with by the first damper 11 a, and thus enters the first indoor heat exchange units 4 a and 4 b without entering the second indoor heat exchange unit 5 a. Since the second damper 12 a is in the open state, the outside air is sucked through the second air inlet 14 a and enters the second indoor heat exchange unit 5 a.
At this time, when the refrigeration cycle apparatus 100 operates in heating mode, the first indoor heat exchange units 4 a and 4 b, and the second indoor heat exchange unit 5 a are in a state in which the subcooled liquid region is reduced as illustrated by the solid line in FIG. 3 , and accordingly the efficiency of the heat exchanger increases in its entirety.
In contrast, in FIG. 5(e), the second damper 12 a is in the closed state, while the first damper 11 a is in the open state. In the state illustrated in FIG. 5(e), while the room air enters from the first air inlet 13, the outside air does not enter from the second air inlet 14 a since the second damper 12 a seals the second air inlet 14 a. The room air having entered from the first air inlet 13 enters the first indoor heat exchange units 4 a and 4 b and the second indoor heat exchange unit 5 a.
At this time, when the refrigeration cycle apparatus 100 operates in heating mode, the state in the first indoor heat exchange units 4 a and 4 b, and the second indoor heat exchange unit 5 a are brought into the same state as in the existing heat exchanger illustrated by the dotted line in FIG. 3 , into which outside air is not drawn.

Working Example 2

FIGS. 6(a) to 6(c) illustrate the structure and operation of the indoor unit 3 in Working Example 2, and illustrate a flow of air inside the indoor unit 3. FIG. 6(a) is a perspective view illustrating the structure of an indoor unit 3 b in its entirety. FIGS. 6(b) and 6(c) are rear views of the indoor unit 3 b, which is viewed from the rear. Note that the differences between Working Example 1 illustrated in FIGS. 5(a) to 5(e) and Working Example 2 illustrated in FIGS. 6(a) to 6(c) will be described below.
At the rear face of the indoor unit 3 b illustrated in FIGS. 6(a) to 6(c), a second air inlet 14 b is provided through which outside air is sucked. In Working Example 2, the location and shape of the second air inlet 14 b are different from the location and shape of the second air inlet in Working Example 1. The indoor unit 3 b has first indoor heat exchange units 4 a, 4 b, and 4 c, and second indoor heat exchange units 5 b and 5 c accommodated in the indoor unit 3 b. In Working Example 2, the shapes of the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5 are different from the shapes of the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5 in Working Example 1.
Further, the indoor unit 3 b has a first damper 11 b and a second damper 12 b accommodated in the indoor unit 3 b. The second damper 12 b is located in the vicinity of the second air inlet 14 b. The second damper 12 b has a shape substantially the same as a shape of the second air inlet 14 b. Additionally, the second damper 12 b is larger in size than the second air inlet 14 b. FIG. 6(b) illustrates the example in which the second damper 12 b is located on the right of the second air inlet 14 b along the rear face of the indoor unit 3 b. While the second air inlet 14 b has a substantially square shape, the second damper 12 b also has a substantially square shape. The second damper 12 b has a width and a length that are both greater than a width and a length of the second air inlet 14 b.
Furthermore, the second damper 12 b has an operating means (not illustrated) and operates such that the second damper 12 b is brought into any of an open state in which the second damper 12 b does not interfere with outside air flowing from the second air inlet 14 b into the indoor unit 3 b, a closed state in which the second damper 12 b closes the second air inlet 14 b and stops the outside air from entering the indoor unit 3 b, and a half-open state that is intermediate between the open state and the closed state. FIG. 6(b) illustrates the example in which the second damper 12 b is positioned on the right of the second air inlet 14 b and in an open state in which the second damper 12 b does not close the second air inlet 14 b. In contrast, FIG. 6(c) illustrates the example in which the second damper 12 b has moved to a position at which the second damper 12 b closes the second air inlet 14 b from the inner side, and is in a closed state in which the second damper 12 b closes the second air inlet 14 b. Note that, when the second damper 12 b is in the closed state, since the second damper 12 b is greater in size than the second air inlet 14 b, the second damper 12 b can completely seal the second air inlet 14 b.
Note that, as the operating means configured to change the state of the second damper 12 b, any type of means can be used. For example, a rail may be installed for the second damper 12 b to move the second damper 12 b along the rail.
The first damper 11 b is located inside the indoor unit 3 b and between the first air inlet 13 and the second indoor heat exchange units 5 b and 5 c. FIGS. 6(a) and 6 (b) illustrate the example in which the first damper 11 b is installed in the rear face of the indoor unit 3 b below the first air inlet 13.
Note that, while the shape of the first damper 11 b is not particularly limited, the first damper 11 b has a size large enough to stop the room air sucked through the first air inlet 13 from entering the second indoor heat exchange units 5 b and 5 c. In the example in FIGS. 6(a) and 6(b), the first damper 11 b has a width greater than a width of the second indoor heat exchange unit 5 b, and a length greater than the distance from the rear face of the indoor unit 3 b to the front-side end portion of the second indoor heat exchange unit 5 b. The first damper 11 b has the size as described above, and when the first damper 11 b is in a closed state, which will be described later, the first damper 11 b thus can stop the room air from entering the second indoor heat exchange units 5 b and 5 c.
Furthermore, the first damper 11 b has an operating means (not illustrated) and operates such that the first damper 11 b is brought into any of a closed state in which the first damper 11 b stops room air sucked through the first air inlet 13 from entering the second indoor heat exchange units 5 b and 5 c, an open state in which the first damper 11 b does not interfere with the room air entering the second indoor heat exchange units 5 b and 5 c, and a half-open state that is intermediate between the open state and the closed state. FIGS. 6(a) and 6(b) illustrate the example in which the first damper 11 b is in the closed state. At this time, the first damper 11 b has the width greater than the width of the second indoor heat exchange unit 5 b, and the length greater than the distance from the rear face of the indoor unit 3 b to the front-side end portion of the second indoor heat exchange unit 5 b. This configuration can stop the room air from entering the second indoor heat exchange units 5 b and 5 c. In contrast, FIG. 6(c) illustrates the example in which the first damper 11 b is in the open state. At this time, since the first damper 11 b is not positioned between the first air inlet 13 and the second indoor heat exchange units 5 b and 5 c, the first damper 11 b allows the room air to enter the second indoor heat exchange units 5 b and 5 c.
Note that, as the operating means configured to change the state of the first damper 11 b, any type of means can be used. For example, a rail may be installed for the first damper 11 b to move the first damper 11 b along the rail.
FIGS. 6(b) and 6(c) illustrate airflow in the indoor unit 3 b when the indoor unit 3 b is viewed from the rear. In FIG. 6(b), the second damper 12 b is in the open state, while the first damper 11 b is in the closed state. In contrast, in FIG. 6(c), the second damper 12 b is in the closed state, while the first damper 11 b is in the open state.
In the state illustrated in FIG. 6(b), the room air enters the indoor unit 3 b from the first air inlet 13, while the outside air enters the indoor unit 3 b from the second air inlet 14 b. Note that the room air sucked through the first air inlet 13 is interfered with by the first damper 11 b, and thus enters the first indoor heat exchange units 4 a, 4 b, and 4 c without entering the second indoor heat exchange units 5 b and 5 c. Since the second damper 12 b is in the open state, the outside air is sucked through the second air inlet 14 b and enters the second indoor heat exchange units 5 b and 5 c.
At this time, when the refrigeration cycle apparatus 100 operates in heating mode, the first indoor heat exchange units 4 a, 4 b, and 4 c, and the second indoor heat exchange units 5 b and 5 c are in a state in which the subcooled liquid region is reduced as illustrated by the solid line in FIG. 3 , and accordingly the efficiency of the heat exchanger increases in its entirety.
In contrast, in FIG. 6(c), the second damper 12 b is in the closed state, while the first damper 11 b is in the open state. In the state illustrated in FIG. 6(c), while the room air enters from the first air inlet 13, the outside air does not enter from the second air inlet 14 b since the second damper 12 b seals the second air inlet 14 b. The room air having entered from the first air inlet 13 enters the first indoor heat exchange units 4 a, 4 b, and 4 c, and the second indoor heat exchange units 5 b and 5 c.
At this time, when the refrigeration cycle apparatus 100 operates in heating mode, the first indoor heat exchange units 4 a, 4 b, and 4 c, and the second indoor heat exchange units 5 b and 5 c are brought into the same state as in the existing heat exchanger illustrated by the dotted line in FIG. 3 , into which outside air is not drawn.

Working Example 3

FIGS. 7(a) to 7(c) illustrate the structure and operation of the indoor unit 3 in Working Example 3, and illustrate a flow of air inside the indoor unit 3. FIG. 7(a) is a perspective view illustrating the structure of an indoor unit 3 c in its entirety. FIGS. 7(b) and 7(c) are front views of the indoor unit 3 c, which is viewed from the front. Note that the differences between Working Example 1 illustrated in FIGS. 5(a) to 5(e) and Working Example 3 illustrated in FIGS. 7(a) to 7(c) and between Working Example 2 illustrated in FIGS. 6(a) to 6(c) and Working Example 3 illustrated in FIGS. 7(a) to 7(c) will be described below.
On the right of the indoor unit 3 c illustrated in FIGS. 7(a) to 7(c), a second air inlet 14 c is provided through which outside air is sucked. In Working Example 3, the second air inlet 14 c is provided at a position different from the position in Working Examples 1 and 2. Similarly to Working Example 2, the indoor unit 3 c has the first indoor heat exchange units 4 a, 4 b, and 4 c, and the second indoor heat exchange units 5 b and 5 c accommodated in the indoor unit 3 c.
Further, the indoor unit 3 c has a first damper 11 c and a second damper 12 c accommodated in the indoor unit 3 c. The second damper 12 c is located in the vicinity of the second air inlet 14 c. The second damper 12 c has a shape substantially the same as a shape of the second air inlet 14 c. Additionally, the second damper 12 c is larger in size than the second air inlet 14 c. FIG. 7(a) illustrates the example in which the second damper 12 c is located below the second air inlet 14 c along the right face of the indoor unit 3 c. While the second air inlet 14 c has a square shape, the second damper 12 c also has a square shape. The second damper 12 c has a width and a length that are both greater than a width and a length of the second air inlet 14 c.
Furthermore, the second damper 12 c has an operating means (not illustrated) and operates such that the second damper 12 c is brought into any of an open state in which the second damper 12 c does not interfere with outside air flowing from the second air inlet 14 c into the indoor unit 3 c, a closed state in which the second damper 12 c closes the second air inlet 14 c and stops the outside air from entering the indoor unit 3 c, and a half-open state that is intermediate between the open state and the closed state. FIG. 7(b) illustrates the example in which the second damper 12 c is positioned below the second air inlet 14 c and is in an open state in which the second damper 12 c does not close the second air inlet 14 c. In contrast, FIG. 7(c) illustrates the example in which the second damper 12 c has moved and is thus in a closed state in which the second damper 12 c closes the second air inlet 14 c. Note that, when the second damper 12 c is in the closed state, since the second damper 12 c is greater in size than the second air inlet 14 c, the second damper 12 c can completely seal the second air inlet 14 c.
Note that, as the operating means configured to change the state of the second damper 12 c, any type of means can be used. For example, the operating means of the second damper 12 c may be manually operated by a user. FIGS. 8(a) and 8(b) illustrate an example in which the operating means of the second damper 12 c is manually operated. As illustrated in FIGS. 8(a) and 8(b), slits 20 with protruding portions may be provided at the right face of the indoor unit 3 c, and tabs 21 that are movable along the slits 20 may be attached to the second damper 12 c, and a user thus can move the tabs 21 to operate the second damper 12 c.
In FIG. 8(a), the second damper 12 c is brought into the open state by the operating means described above. In FIG. 8(b), the second damper 12 c is brought into the closed state by the operating means described above. Note that, in FIGS. 8(a) and 8(b), the protruding portions are also provided at the middle of the respective slits 20, and the second damper 12 c can be brought into the half-open state by a user moving the tabs 21 to the middle protruding portions described above.
The first damper 11 c is located inside the indoor unit 3 c and between the first air inlet 13 and the second indoor heat exchange units 5 b and 5 c. In the example illustrated in FIGS. 7(a) and 7(b), the first damper 11 c is installed in the rear face of the indoor unit 3 c below the first air inlet 13. The shape and operation of the first damper 11 c in the present working example are substantially the same as the shape and operation of the first damper 11 b in Working Example 2. However, it is necessary to avoid the first damper 11 c from interfering with the second damper 12 c as will be described later.
Note that, while the shape of the first damper 11 c is not particularly limited, the first damper 11 c has a size large enough to stop the room air sucked through the first air inlet 13 from entering the second indoor heat exchange units 5 b and 5 c. In the example in FIGS. 7(a) and 7(b), similarly to Working Example 2, the first damper 11 c has a width greater than the width of the second indoor heat exchange unit 5 b, and a length greater than the distance from the rear face of the indoor unit 3 c to the front-side end portion of the second indoor heat exchange unit 5 b.
In addition, the first damper 11 c needs to have a size such that the first damper 11 c does not interfere with the second damper 12 c when the second damper 12 c is in the closed state and the first damper 11 c is in an open state, which will be described later.
Furthermore, the first damper 11 c has an operating means (not illustrated) and operates such that the first damper 11 c is brought into any of a closed state in which the first damper 11 c stops room air sucked through the first air inlet 13 from entering the second indoor heat exchange units 5 b and 5 c, an open state in which the first damper 11 c does not interfere with the room air entering the second indoor heat exchange units 5 b and 5 c, and a half-open state that is intermediate between the open state and the closed state. FIGS. 7(a) and 7(b) illustrate the example in which the first damper 11 c is in the closed state. In contrast, FIG. 7(c) illustrates the example in which the first damper 11 c is in the open state.
As the operating means configured to change the state of the first damper 11 c, any type of means can be used. Note that the operating means of the first damper 11 c needs to have a size such that the first damper 11 c does not interfere with the second damper 12 c when the second damper 12 c is in the closed state and the first damper 11 c is in the open state.
FIGS. 7(b) and 7(c) illustrate a flow of air in the indoor unit 3 c when the indoor unit 3 c is viewed from the front. In FIG. 7(b), the second damper 12 c is in the open state, while the first damper 11 c is in the closed state. In contrast, in FIG. 7(c), the second damper 12 c is in the closed state, while the first damper 11 c is in the open state.
In the state illustrated in FIG. 7(b), room air enters the indoor unit 3 c from the first air inlet 13, while outside air enters the indoor unit 3 c from the second air inlet 14 c. Note that the room air sucked through the first air inlet 13 is interfered with by the first damper 11 c, and thus enters the first indoor heat exchange units 4 a, 4 b, and 4 c without entering the second indoor heat exchange units 5 b and 5 c. Since the second damper 12 c is in the open state, the outside air is sucked through the second air inlet 14 c and enters the second indoor heat exchange units 5 b and 5 c.
At this time, when the refrigeration cycle apparatus 100 operates in heating mode, the first indoor heat exchange units 4 a, 4 b, and 4 c, and the second indoor heat exchange units 5 b and 5 c are in a state in which the subcooled liquid region is reduced as illustrated by the solid line in FIG. 3 , and accordingly the efficiency of the heat exchanger increases in its entirety.
In contrast, in FIG. 7(c), the second damper 12 c is in the closed state, while the first damper 11 c is in the open state. In the state illustrated in FIG. 7(c), while room air enters from the first air inlet 13, outside air does not enter from the second air inlet 14 c since the second damper 12 c seals the second air inlet 14 c. The room air having entered from the first air inlet 13 enters the first indoor heat exchange units 4 a, 4 b, and 4 c, and the second indoor heat exchange units 5 b and 5 c. At this time, when the refrigeration cycle apparatus 100 operates in heating mode, the state in the first indoor heat exchange units 4 a, 4 b, and 4 c, and the second indoor heat exchange units 5 b and 5 c is the same as the state in the existing heat exchanger illustrated by the dotted line in FIG. 3 , into which outside air is not drawn.
As explained above, the refrigeration cycle apparatus 100 in the present disclosure has the first indoor heat exchange unit 4 and the second indoor heat exchange unit 5. The indoor unit 3 is provided with the first air inlet 13 through which room air is sucked, and the second air inlet 14 through which outside air is sucked. Further, the first damper 11 and the second damper 12 are installed in the indoor unit 3.
When the refrigeration cycle apparatus 100 performs heating operation, the second damper 12 is brought into the open state, while the first damper 11 is brought into the closed state, and low-temperature outside air thus enters the second indoor heat exchange unit 5. With this configuration, ventilation is provided by drawing the outside air into a room. In addition, in the second indoor heat exchange unit 5, the amount of heat exchange between the refrigerant and the outside air increases, and the temperature of outside air entering the indoor unit thus can be quickly increased. Therefore, although ventilation is provided by allowing the outside air to enter the room, a reduction in the heating capacity is less likely to occur.
Further, as the efficiency of the second indoor heat exchange unit 5 improves, the ratio between high-pressure and low-pressure in the refrigeration cycle apparatus 100 decreases, the refrigeration cycle apparatus 100 achieves energy saving. Note that, when the outside air temperature is almost equal to the room air temperature, or when the outside air is contaminated, the second damper 12 is brought into the closed state, while the first damper 11 is brought into the open state, and the refrigeration cycle apparatus 100 thus can operate substantially the same as the existing refrigeration cycle apparatus.
Note that, in Working Examples 1, 2, and 3, the first damper 11 and the second damper 12 have been described as being in the open state or the closed state, however, the first damper 11 and the second damper 12 may be each brought into the half-open state. This allows for adjustment of the amount of outside air and the amount of room air entering the second indoor heat exchange unit 5.
In Working Examples 1, 2, and 3, the partition wall 18 can also be provided to more reliably separate room air flowing in the indoor unit 3 from outside air.
FIGS. 9(a), 9(b), and 9(c) illustrate the structure of the indoor unit 3 a in Working Example 1 when the partition wall 18 is provided inside the indoor unit 3 a.
FIGS. 9(a), 9(b), and 9(c) illustrate an example in which the partition wall 18 is attached to the rear face of the indoor unit 3 a with the first damper 11 a located at the tip end portion of the partition wall 18. Therefore, in FIGS. 9(a), 9(b), and 9(c), both the partition wall 18 and the first damper 11 a are located between the first air inlet 13 and the second indoor heat exchange unit 5 a.
Note that, in the case illustrated in FIGS. 9(a), 9(b), and 9(c), the first damper 11 a operates, for example, such that the first damper 11 a rotates about its connection portion with the partition wall 18. Specifically, in FIG. 9(b), the first damper 11 a is in the closed state, and prevents the room air sucked through the first air inlet 13 from flowing to the second indoor heat exchange unit 5 a. In contrast, in FIG. 9(c), the first damper 11 a has rotated about its connection portion with the partition wall 18 and is thus in the open state. Therefore, the first damper 11 a allows the room air sucked through the first air inlet 13 to enter the second indoor heat exchange unit 5 a.
The partition wall 18 and the first damper 11 a are located in the manner as described above, which helps easily control a flow of air in the indoor unit 3 a. This facilitates making use of the capacity of the refrigeration cycle apparatus as designed.
FIGS. 10(a) and 10(b) illustrate the structure of the indoor unit 3 b in Working Example 2 when the partition wall 18 is provided inside the indoor unit 3 b.
In FIGS. 10(a) and 10(b), the partition wall 18 is provided on the left of the second air inlet 14 b. In FIG. 10(a), the second damper 12 b is in the open state, and outside air is sucked through the second air inlet 14 into the indoor unit 3 b and flows to the second indoor heat exchange unit 5 c. At this time, room air is sucked through the first air inlet 13 into the indoor unit 3 b, however, this room air flows in a direction limited by the first damper 11 b and the partition wall 18, and thus very little amount of the room air flows to the second indoor heat exchange unit 5 c.
In FIG. 10(b), the first damper 11 b is in the open state. When FIG. 10(a) and FIG. 10(b) are compared to each other, the first damper 11 b moves transversely in the drawings, while the partition wall 18 is provided such that the movement of the first damper 11 b described above is allowed. Therefore, even in a case where the partition wall 18 is provided, the first damper 11 b still operates properly, and in addition, flows of room air and outside air in the indoor unit 3 b can be reliably controlled. This facilitates making use of the capacity of the refrigeration cycle apparatus as designed.

INDUSTRIAL APPLICABILITY

The refrigeration cycle apparatus of the present disclosure is particularly applicable to performing heating operation while providing ventilation.

Claims

1. A refrigeration cycle apparatus comprising:

an indoor unit provided with a first air inlet communicating with an inside of a room and a second air inlet communicating with outside of the room;

a first heat exchange unit located in a first air flow passage connecting the first air inlet and an air outlet;

a second heat exchange unit located in a second air flow passage connecting the second air inlet and the air outlet, the second heat exchange unit being connected to the first heat exchange unit such that the second heat exchange unit is positioned downstream of the first heat exchange unit when the refrigeration cycle apparatus performs heating operation;

a first damper capable of adjusting an amount of air entering from the first air flow passage to the second air flow passage; and

a second damper provided at the second air inlet and capable of adjusting an amount of air to be sucked from the second air inlet.

2. The refrigeration cycle apparatus of claim 1, wherein

a partition wall is provided inside the indoor unit, the partition wall separating the first air flow passage from the second air flow passage,

the partition wall is provided with a communication portion through which the first air flow passage and the second air flow passage communicate with each other, and

the first damper is installed at the communication portion, and is capable of adjusting an amount of air flowing through the communication portion.

3. The refrigeration cycle apparatus of claim 1, comprising:

a first fan configured to suck air from the first air inlet and feed the air to the first heat exchange unit; and

a second fan configured to suck outside air from the second air inlet and feed the air to the second heat exchange unit.

4. The refrigeration cycle apparatus of claim 1, wherein a filter removing dust and dirt is installed at the second air inlet.

5. The refrigeration cycle apparatus of claim 1, wherein the second damper is larger in size than the second air inlet.

6. The refrigeration cycle apparatus of claim 1, wherein the first heat exchange unit has a volume larger than a volume of the second heat exchange unit.

7. The refrigeration cycle apparatus of claim 1, wherein the second air inlet is provided at a rear face of the indoor unit.

8. The refrigeration cycle apparatus of claim 1, wherein the second air inlet is provided at a lateral face of the indoor unit.