REFRIGERATION CYCLE DEVICE AND AIR CONDITIONER EQUIPPED WITH THE SAME

Description

TECHNICAL FIELD

The present disclosure relates to the field of air conditioner technology, and in particular, to a refrigeration cycle device and an air conditioner having the refrigeration cycle device.

BACKGROUND

When an air conditioner is used for heating during cold seasons, a surface temperature of an outdoor heat exchanger is low, and an ambient temperature outside is also low, so that frosting often occurs on a surface of the outdoor heat exchanger. In order to melt the frost on the outdoor heat exchanger, a defrosting operation is usually carried out to defrost the outdoor heat exchanger.

Comparative document 1 disclosed an air conditioner, and specifically disclosed that in a refrigerant loop, a part of a refrigerant pipe connecting an outdoor heat exchanger and an expansion valve between the outdoor heat exchanger and a bottom surface. In this way, during a defrosting operation, a drainage below the outdoor heat exchanger can be prevented from frosting or freezing by the heat in the refrigerant pipe, and the ice can be rapidly melted.

PRIOR ART

Patent Documents

• • Patent Document 1: Chinese Published Patent: CN102187158A

SUMMARY OF INVENTION

Technical Problem to be Solved by the Invention

However, in Patent Document 1, since the defrosting operation was performed by using a refrigerant that had passed through an indoor heat exchanger during the defrosting operation, a temperature of the refrigerant was not high, and a defrosting effect was not good.

Therefore, it is necessary to provide an air conditioner capable of preventing frosting or freezing of the drainage below the outdoor heat exchanger and effectively melting ice.

Technical Solutions for Solving Technical Problems

To solve the above problems, a refrigeration cycle device provided by an embodiment of the present invention includes: a refrigeration cycle portion including a compressor, a first indoor heat exchanger, an outdoor heat exchanger, and a first expansion valve, a discharge portion of the compressor is capable of discharging a compressed refrigerant. The refrigeration cycle device further includes an outdoor device housing having a chassis and configured for accommodating the outdoor heat exchanger; and an anti-freeze pipe arranged on the chassis, and the refrigerant discharged from the discharge portion flowing into the anti-freeze pipe without passing through the first indoor heat exchanger.

To solve the above problems, an air conditioner provided by another embodiment of the present invention includes the above-mentioned refrigeration cycle device; a first indoor fan; an outdoor fan received in the outdoor device housing; and a first indoor device housing receiving the first indoor heat exchanger and the first indoor fan.

To solve the above problems, an air conditioner provided by yet another embodiment of the present invention includes the above-mentioned refrigeration cycle device; a first indoor fan; an outdoor fan received in the outdoor device housing; a first indoor device housing receiving the first indoor heat exchanger and the first indoor fan; a control portion configured to control the refrigeration cycle portion, the first indoor fan, and the on-off valve; and a judgment portion configured to determine whether the on-off valve is in an open state or a closed state based on a temperature difference between a temperature of the refrigerant flowed into the anti-freeze pipe via the on-off valve and a temperature of the refrigerant discharged from the compressor, when the control portion has controlled the on-off valve to switch to the open state and the judgment portion determines that the on-off valve is in the closed state, or when the control portion has controlled the on-off valve to switch to the closed state and the judgment portion determines that the on-off valve is in the open state, the control portion controls the compressor to stop.

To solve the above problems, an air conditioner provided by yet another embodiment of the present invention includes the above-mentioned refrigeration cycle device; a first indoor fan; an outdoor fan received in the outdoor device housing; a first indoor device housing receiving the first indoor heat exchanger and the first indoor fan; a control portion configured to control the refrigeration cycle portion, the first indoor fan, and the on-off valve; and a judgment portion configured to determine whether the on-off valve is in an open state or a closed state based on a temperature difference between a temperature of the refrigerant flowed into the anti-freeze pipe via the on-off valve and a temperature of the refrigerant discharged from the discharge portion, when the control portion has controlled the on-off valve to switch to the open state and the judgment portion determines that the on-off valve is in the closed state, the control portion does not stop an operation of the compressor, when the control portion has controlled the on-off valve to switch to the closed state and the judgment portion determines that the on-off valve is in the open state, the control portion controls the compressor to stop.

Advantageous Effects

According to the refrigeration cycle device and the air conditioner of the present disclosure, the high-temperature refrigerant discharged from the discharge portion of the compressor can be quickly delivered into the anti-freeze pipe. Therefore, it can more effectively inhibit the freezing of a lower part of the outdoor heat exchanger and promote the melting of ice.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a structural block diagram of an air conditioner according to a first embodiment of the present disclosure.

FIG. 2 is a schematic configuration diagram of the air conditioner shown in FIG. 1.

FIG. 3 is a schematic configuration diagram of the air conditioner shown in FIG. 2 during a refrigeration operation.

FIG. 4 is a schematic configuration diagram of the air conditioner shown in FIG. 2 during a first heating operation.

FIG. 5 is a schematic configuration diagram of the air conditioner shown in FIG. 2 during a second heating operation.

FIG. 6 is a schematic configuration diagram of the air conditioner shown in FIG. 2 during a defrosting operation.

FIG. 7 is a stereoscopic structure schematic diagram of an outdoor device of the air conditioner shown in FIG. 1.

FIG. 8 is a stereoscopic structure schematic diagram of the outdoor device shown in FIG. 7, viewed from another angle.

FIG. 9 is a structural schematic diagram of a bottom surface of the outdoor device shown in FIG. 7.

FIG. 10 is a flowchart of a heating operation of the air conditioner shown in FIG. 1.

FIG. 11 is a schematic configuration diagram of an air conditioner according to a second embodiment during the refrigeration operation.

FIG. 12 is a schematic configuration diagram of the air conditioner according to the second embodiment during the second heating operation.

FIG. 13 is a schematic configuration diagram of the air conditioner according to the second embodiment during the defrosting operation.

FIG. 14 is a schematic configuration diagram of the air conditioner according to the present embodiment wherein a second expansion valve is closed in the second heating operation shown in FIG. 12.

FIG. 15 is a schematic configuration diagram of a modification of the second embodiment.

DETAILED DESCRIPTION

Each embodiment of the present invention is hereinafter described with reference to the drawings. In the following description, the same components are given the same reference characters, and their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

First Embodiment

Hereinafter, an air conditioner according to the first embodiment of the present invention will be described with reference to the drawings.

<Overall Structure of the Air Conditioner>

Referring to FIG. 1 to FIG. 5, FIG. 1 is a structural block diagram of the air conditioner 100 of this embodiment, FIG. 2 is a schematic configuration diagram of the air conditioner 100 of this embodiment, FIG. 3 is a schematic configuration diagram of the air conditioner 100 of this embodiment during a refrigeration operation, FIG. 4 is a schematic configuration diagram of the air conditioner 100 of this embodiment during a first heating operation, FIG. 5 is a schematic configuration diagram of the air conditioner 100 of this embodiment during a second heating operation, and FIG. 6 is a schematic configuration diagram of the air conditioner 100 of this embodiment during a defrosting operation.

As shown in FIG. 1 to FIG. 5, the air conditioner 100 of this embodiment includes an outdoor device 10 arranged outdoors, an indoor device 30 arranged indoors, and a remote controller 40.

Referring to FIG. 1, FIG. 2, FIG. 7, and FIG. 8, the outdoor device 10 includes an outdoor device housing 11, a compressor 12, a four-way valve 13, an outdoor heat exchanger 14, an anti-freeze pipe 15, an on-off valve 16, and an outdoor fan 17. The outdoor device housing 11 receives components such as the compressor 12, the outdoor heat exchanger 14, the anti-freeze pipe 15, and the outdoor fan 17, and is provided with an air outlet 111 opposite to the outdoor fan 17 so as to discharge air that has undergone heat exchanges to outside of the outdoor device 10. The indoor device 30 includes an indoor device housing (not shown), an indoor heat exchanger 32, an expansion valve 33, and an indoor fan 34. The indoor device housing receives the indoor heat exchanger 32, the expansion valve 33, and the indoor fan 34. The remote controller 40 serves as an operating device configured for starting and stopping operations for various operation modes and switching the operation modes. In addition, the remote controller 40 can set a target temperature of an indoor temperature, an air volume, and an air direction. Instructions inputted into the remote controller 40 by user's operations are transmitted to a control portion 50 described later, enabling the air conditioner 100 to execute the various operation modes and the like.

The air conditioner 100 includes a refrigeration cycle device. The refrigeration cycle device includes a refrigeration cycle portion, the outdoor device housing 11, the anti-freeze pipe 15, the on-off valve 16, and the control portion 50. The refrigeration cycle portion is configured by sequentially connecting the compressor 12, the four-way valve 13, the outdoor heat exchanger 14, the expansion valve 33, and the indoor heat exchanger 32 through pipes. In another words, the refrigeration cycle portion includes the compressor 12, the four-way valve 13, the indoor heat exchanger 32, the expansion valve 33, and the outdoor heat exchanger 14, and the control portion 50 controls the refrigeration cycle portion and the on-off valve 16.

Hereinafter, each of the above components will be described in detail.

The compressor 12 is a mechanism that compresses a low-pressure refrigerant to a high-pressure refrigerant in the refrigeration cycle device. The compressor 12 is, for example, a compressor driven to rotate by a motor. The motor of the compressor 12 can be controlled for a rotation speed (frequency) through an inverter or other means. Specifically, the compressor 12 includes a discharge portion 121 and a suction portion 122. The discharge portion 121 and the suction portion 122 are respectively connected to different connection ports of the four-way valve 13. When the compressor 12 is operating, the low-pressure refrigerant is sucked in from the suction portion 122. After the refrigerant has been compressed to generate the high-pressure refrigerant, the compressed refrigerant is discharged from the discharge portion 121.

The four-way valve 13 is a valve that switches circulation directions of the refrigerant corresponding to the refrigeration operation or the heating operation in the refrigeration cycle device, and the four-way valve 13 is connected to the discharge portion 121 of the compressor 12, the suction portion 122 of the compressor 12, the outdoor heat exchanger 14, and the indoor heat exchanger 32 through pipes. In this embodiment, the four-way valve 13 is provided with an inlet a, an outlet b, a first switching port c, and a second switching port d. The inlet a of the four-way valve 13 is connected to the discharge portion 121 of the compressor 12 through a first pipe 61. The outlet b of the four-way valve 13 is connected to the suction portion 122 of the compressor 12 through a second pipe 62. The first switching port c of the four-way valve 13 is connected to the outdoor heat exchanger 14 through a third pipe 63. The second switching port d of the four-way valve 13 is connected to the indoor heat exchanger 32 through a fourth pipe 64. Based on a control signal sent from the control portion 50 of the air conditioner 100, the four-way valve 13 is switchable between a first state in which the refrigerant discharged from the discharge portion 121 flows into the indoor heat exchanger 32 and a second state in which the refrigerant discharged from the discharge portion 121 flows into the outdoor heat exchanger 14. In this embodiment, the first state refers to the heating operation, and the second state refers to the refrigeration operation or the defrosting operation.

The expansion valve 33 is configured to cause the refrigerant flowing between the outdoor heat exchanger 14 and the indoor heat exchanger 32 to expand to reduce pressure. The expansion valve 33 is, for example, an electric expansion valve whose opening degree can be controlled. During the refrigeration operation, the expansion valve 33 is used to reduce the pressure of the high-pressure refrigerant, which has dissipated heat in the outdoor heat exchanger 14, before delivering the refrigerant to the indoor heat exchanger 32. During the heating operation, the expansion valve 33 is used to reduce the pressure of the high-pressure refrigerant, which has dissipated heat in the indoor heat exchanger 32, before delivering the refrigerant to the outdoor heat exchanger 14. In this embodiment, the expansion valve 33 is arranged on the fifth pipe 65 that is configured for connecting the outdoor heat exchanger 14 and the indoor heat exchanger 32.

The outdoor heat exchanger 14 is received in the outdoor device housing 11 and arranged opposite to the outdoor fan 17 to perform the heat exchange between the air sucked into the outdoor device 10 by the outdoor fan 17 and the refrigerant. The outdoor heat exchanger 14 serves as an evaporator during the refrigeration operation and as a condenser during the heating operation.

The indoor heat exchanger 32 performs the heat exchange between the air sucked into the indoor device 30 by the indoor fan 34 and the refrigerant. The indoor heat exchanger 32 serves as the condenser during the refrigeration operation and as the evaporator during the heating operation.

As shown in FIG. 7 to FIG. 9, the anti-freeze pipe 15 is arranged on a chassis 112 of the outdoor device housing 11, and is configured to be located between the outdoor heat exchanger 14 and the chassis 112 of the outdoor device housing 11 when viewed from the top. When the on-off valve 16 is in an open state, the refrigerant discharged from the discharge portion 121 of the compressor 12 flows directly into the anti-freeze pipe 15 without passing through the indoor heat exchanger 32. Specifically, one end of the anti-freeze pipe 15 is connected to the first pipe 61, which connects the discharge portion 121 of the compressor 12 and the inlet a of the four-way valve 13, through the sixth pipe 66, and the other end is connected to the third pipe 63, which connects the four-way valve 13 and the outdoor heat exchanger 14, through the seventh pipe 67. Wherein, the sixth pipe 66, the anti-freeze pipe 15, and the seventh pipe 67 form a heat pipe, so as to prevent the chassis 112 of the outdoor heat exchanger 14 from frosting or to effectively melt the ice formed on the chassis 112.

In this embodiment, during the defrosting operation, the refrigerant can flow directly into the anti-freeze pipe 15 without passing through the indoor heat exchanger 32. Thus, the temperature of the refrigerant reaching the anti-freeze pipe 15 is relatively high, which can more effectively inhibit the freezing of the lower part of the outdoor heat exchanger 14 and promote the melting of ice.

The on-off valve 16 is arranged on the sixth pipe 66, one end of the sixth pipe 66 away from the anti-freeze pipe 15 is connected to the first pipe 61 that connect the discharge portion 121 of the compressor 12 and the inlet a of the four-way valve 13. Thus, the on-off valve 16 is switchable between a closed state in which the refrigerant does not flow into the anti-freeze pipe 15 and an open state in which the refrigerant flows into the anti-freeze pipe 15, so as to control the flow directions of the refrigerant. Specifically, when the on-off valve 16 is closed, the refrigerant discharged from the discharge portion 121 does not flow into the anti-freeze pipe 15. When the on-off valve 16 is open, the refrigerant discharged from the discharge portion 121 can flow directly into the anti-freeze pipe 15 without passing through the first indoor heat exchanger 32. As a result, the high-temperature refrigerant discharged from the discharge portion 121 can flow into the anti-freeze pipe 15 by opening the on-off valve 16, which can further prevent the chassis 112 of the outdoor device housing 11 from freezing or quickly melting ice formed on the chassis 112. Therefore, ice formation on the chassis 112 can be more effectively inhibited, and ice melting can be promoted.

Furthermore, when the on-off valve 16 is in the open state, the refrigerant discharged from the discharge portion 121 can directly flow into the anti-freeze pipe 15 for the defrosting operation. In this way, the high-temperature refrigerant can quickly dissolve the frost formed on the outdoor heat exchanger 14 or prevent the chassis 112 of the outdoor device housing 11 from freezing.

Furthermore, when a first temperature sensor 18 described later detects that the temperature of the refrigerant flowed into the anti-freeze pipe 15 through the on-off valve 16 is higher than a predetermined temperature, the on-off valve 16 is switched to the closed state. The predetermined temperature is, for example, 85° C. (ANSI-UL 60335-2-40 3rd Ed. Nov. 1, 2019). It can be understood that, when the temperature of the refrigerant is detected to be higher than the predetermined temperature, indicating that the frost on the outdoor heat exchanger 14 has been completely removed or the ice has melted, and then the on-off valve 16 is switched to the closed state.

In addition, the outdoor device 10 further includes a first temperature sensor (a anti-freeze pipe temperature sensor) 18 and a second temperature sensor (a compressor discharge temperature sensor) 19. The first temperature sensor 18 is arranged on the anti-freeze pipe 15 and is configured to detect the temperature of the refrigerant flowed into the anti-freeze pipe 15 through the on-off valve 16. The second temperature sensor 19 is arranged at the discharge portion 121 of the compressor 12 and is configured to detect the temperature of the refrigerant discharged from the compressor 12.

Furthermore, the air conditioner 100 further includes a storage portion 51, a communication portion 52, a judgment portion 55, a counting portion 56, etc.

The control portion 50 is composed of, for example, a CPU (Central Processing Unit). The control portion 50 reads and executes programs and data recorded in the storage portion 51, thereby managing the control of the air conditioner 100.

The storage portion 51 is, for example, a ROM (Read Only Memory) and a RAM (Random Access Memory), etc., and records the programs executed by the control portion 50 and various parameters used by the control portion 50.

The communication portion 52 controls, for example, a wireless communication of various data with the remote controller 40. The communication portion 52 is not limited to the wireless communication with the remote controller 40, and for example, may also control wireless communications with external terminals such as a server device or a smartphone.

The judgment portion 55 determines whether the on-off valve 16 is in the open state or the closed state based on a temperature difference between the temperature of the refrigerant flowed into the anti-freeze pipe 15 through the on-off valve 16 and the temperature of the refrigerant discharged from the compressor 12.

When the control portion 50 has controlled the on-off valve 16 to switch to the open state, but the judgment portion 55 determines that the on-off valve 16 is in the closed state; or when the control portion 50 has controlled the on-off valve 16 to switch to the closed state, but the judgment portion 55 determines that the on-off valve 16 is in the open state, indicating that the on-off valve 16 is in a faulty state, and then the control portion 50 controls the compressor 12 to stop.

In a specific embodiment, if the temperature difference between the temperature of the refrigerant flowed into the anti-freeze pipe 15 from the on-off valve 16, which is detected by the first temperature sensor 18, and the temperature of the refrigerant discharged from the compressor 12, which is detected by the second temperature sensor 19, is below a predetermined value or a tendency of change in the temperature difference within the predetermined time (for example, 1 minute) is a decreasing trend, the on-off valve 16 is determined to be in the open state. If the temperature difference is above the predetermined value or the tendency of change in the temperature difference within a predetermined time (for example, 1 minute) is an increasing trend, the on-off valve 16 is determined to be in the closed state.

It can be understood that, when the on-off valve 16 is controlled to be in the closed state, the refrigerant should not flow into the anti-freeze pipe 15. Therefore, the temperature of the refrigerant flowed into the anti-freeze pipe 15 from the on-off valve 16 detected by the first temperature sensor 18 should remain unchanged, and the temperature difference between it and the temperature of the refrigerant discharged from the compressor 12 detected by the second temperature sensor 19 should be above the predetermined value or the tendency of change in the temperature difference within the predetermined time should be the increasing trend. However, if the temperature difference between the temperature of the refrigerant flowed into the anti-freeze pipe 15 from the on-off valve 16 and detected by the first temperature sensor 18 and the temperature of the refrigerant discharged from the compressor 12 and detected by the second temperature sensor 19 is below the predetermined value or the tendency of change in the temperature difference within the predetermined time is the decreasing trend, it indicates that the on-off valve 16 is in the open state. That is, the on-off valve 16 is in the faulty state, and then the control portion 50 controls the compressor 12 to stop.

Conversely, when the on-off valve 16 is controlled to be in the open state, the refrigerant will flow into the anti-freeze pipe 15. Therefore, the temperature of the refrigerant flowed into the anti-freeze pipe 15 from the on-off valve 16 and detected by the first temperature sensor 18 will increase as the refrigerant flows in the anti-freeze pipe 15, and the temperature difference between it and the temperature of the refrigerant discharged from the compressor 12 and detected by the second temperature sensor 19 should be below the predetermined value or the tendency of change in the temperature difference within the predetermined time should be the decreasing trend. However, when the temperature difference between the temperature of the refrigerant flowed into the anti-freeze pipe 15 from the on-off valve 16 and detected by the first temperature sensor 18 and the temperature of the refrigerant discharged from the compressor 12 and detected by the second temperature sensor 19 is above the predetermined value or the tendency of change in the temperature difference within the predetermined time is the increasing trend, it indicates that the on-off valve 16 is in the closed state, that is, the on-off valve 16 is in the faulty state, and then the control portion 50 controls the compressor 12 to stop.

That is, in this specific embodiment, when the on-off valve 16 is indicated to be in the faulty state, the operation of the compressor 12 is stopped.

In another embodiment, when the control portion 50 controls the on-off valve 16 to switch to the open state and the judgment portion 55 determines that the on-off valve 16 is in the closed state, the control portion 50 does not stop the operation of the compressor 12. When the control portion 50 controls the on-off valve 16 to switch to the closed state and the judgment portion 55 determines that the on-off valve 16 is in the open state, the control portion 50 controls the compressor 12 to stop.

That is, in this specific embodiment, when the control portion 50 controls the on-off valve 16 to switch to the open state and the judgment portion 55 determines that the on-off valve 16 is in the closed state, the control portion 50 does not stop the operation of the compressor 12. That is, even if the on-off valve is in the faulty state in this case, the operation of the compressor 12 is not stopped.

In some embodiments, a counting portion 56 counts for at least one of times of a first counting state and times of a second counting state. The times of the first counting state are the times that the judgment portion 55 determines that the on-off valve 16 is in the closed state when the control portion 50 controls the on-off valve 16 to switch to the open state. The times in the second counting state are the times that the judgment portion 55 determines that the on-off valve 16 is in the open state when the control portion 50 controls the on-off valve 16 to switch to the closed state. When the times counted by the counting portion 56 are no more than predetermined times, the control portion 50 does not stop the operation of the compressor 12.

In one embodiment, the predetermined times can be 3 times. In other embodiments, the predetermined times may also be 2 times, 4 times, 5 times, etc., and is not limited herein.

It can be understood that, there are various reasons for a malfunction of the on-off valve 16. Even in the case of a single occurrence of the malfunction of the on-off valve 16, there is still a possibility that the on-off valve 16 will return to its normal operating state. Therefore, when the on-off valve 16 cannot be opened smoothly, the operation of the compressor 12 is not forced to be stopped.

Especially, when the on-off valve 16 is supposed to be in the open state (for example, during the defrosting operation or at an initial stage of the heating operation), even if the on-off valve 16 fails to be opened, it will only result in the refrigerant not flowing into the anti-freeze pipe 15, but the air conditioner can still operate. Therefore, when the on-off valve 16 is supposed to be in the open state but is actually in the closed state, the operation of the compressor 12 is not forced to be stopped until the times reach the predetermined times or more.

In contrast, when the on-off valve 16 is supposed to be in the closed state but is actually in the open state, the refrigeration cycle cannot work normally. The high-temperature refrigerant, which should originally flow to the indoor heat exchanger side, is used for the anti-freezing purpose. In this case, the operation of the compressor 12 may also be forced to be stopped, but this is not limited herein.

Hereinafter, various operation modes of the air conditioner 100 will be described.

<Refrigeration Operation>

As shown in FIG. 3, when the air conditioner 100 is in the refrigeration operation, the on-off valve 16 is in the closed state. The control portion 50 controls the four-way valve 13 to operate. The refrigerant is discharged from the discharge portion 121 of the compressor 12. The refrigerant sequentially passes through the inlet a of the four-way valve 13, the first switching port c of the four-way valve 13, the outdoor heat exchanger 14, the expansion valve 33, the indoor heat exchanger 32, the second switching port d of the four-way valve 13, and the outlet b of the four-way valve 13, and finally is sucked into the compressor 12 by the suction portion 122 of the compressor 12, thereby completing the refrigeration cycle and repeating the refrigeration cycle.

<Heating Operation>

<First Heating Operation>

As shown in FIG. 4, during an inaction period of the compressor 12, when an instruction to start the operation of the compressor 12 is received, the operation of the compressor 12 is started, that is a beginning period of the heating operation, the on-off valve 16 is in the open state, the control portion 50 controls the four-way valve 13 to operate, and the refrigerant is discharged from the discharge portion 121 of the compressor 12. A first part of the refrigerant sequentially passes through the inlet a of the four-way valve 13, the second switching port d of the four-way valve 13, the indoor heat exchanger 32, the expansion valve 33, the outdoor heat exchanger 14, the first switching port c of the four-way valve 13, and the outlet b of the four-way valve 13, and finally is sucked into the compressor 12 by the suction portion 122 of the compressor 12, thereby completing the heating cycle, and repeating the heating cycle. A second part of the refrigerant sequentially passes through the on-off valve 16, the anti-freeze pipe 15, and converges with the first part of the refrigerant in the third pipe 63, and then sequentially passes through the first switching port c of the four-way valve 13 and the outlet b of the four-way valve 13, and is finally sucked into the compressor 12 by the suction portion 122 of the compressor 12, thereby completing the heating cycle and repeating the heating cycle.

It can be understood that, the instruction is not only in a case of receiving a starting operation instruction from the remote controller 40 etc., but also in a case from a thermo-off (for example, the operation of the compressor 12 has been stopped because a temperature sensor (not shown) located in the indoor device 30 had detected that the indoor temperature reaches a target temperature,) to a thermo-on (for example, when the indoor temperature is detected to be away from the target temperature, the operation of the compressor 12 is started). It can be understood that, in the heating operation and the refrigeration operation, when the temperature sensor in the indoor device 30 detects that the indoor temperature reaches the target temperature, the operation of the compressor 12 will be automatically stopped. When the indoor temperature is detected to be away from the target temperature, the operation of the compressor 12 will be automatically started again. The starting operation instruction for the compressor 12 is an instruction for the four-way valve 13 to be in in the first state to drive the heating operation of the refrigeration cycle portion.

Furthermore, when a predetermined time has elapsed since the start of the operation of the compressor 12, the on-off valve 16 is switched to the closed state.

As a result, within the predetermined time after the start of the heating operation, the on-off valve 16 is open, which allows a part of the refrigerant to flow back into the compressor 12 through the on-off valve 16 and the anti-freeze pipe 15, this can prevent a lack of refrigeration oil by recovering the refrigerant remained in the pipes, and thus ensure that the refrigeration, heating, and defrosting effects are fully exerted during the subsequent operation of the compressor 12.

<Second Heating Operation>

As shown in FIG. 5, when the air conditioner 100 is in the stable heating operation, the on-off valve 16 is in the closed state, the control portion 50 controls the four-way valve 13 to operate, the refrigerant is discharged from the discharge portion 121 of the compressor 12, and then the refrigerant sequentially passes through the inlet a of the four-way valve 13, the second switching port d of the four-way valve 13, the indoor heat exchanger 32, the expansion valve 33, the outdoor heat exchanger 14, the first switching port c of the four-way valve 13, and the outlet b of the four-way valve 13, and is finally sucked into the compressor 12 by the suction portion 122 of the compressor 12, so as to complete the heating cycle and repeat the heating cycle.

(3) Defrosting Operation

As shown in FIG. 6, the first part of the refrigerant discharged from the discharge portion 121 of the compressor 12 sequentially passes through the inlet a of the four-way valve 13, the first switching port c of the four-way valve 13, the outdoor heat exchanger 14, the expansion valve 33, the indoor heat exchanger 32, the second switching port d of the four-way valve 13, and the outlet b of the four-way valve 13, and is finally sucked into the compressor 12 by the suction portion 122 of the compressor 12, and the second part of the refrigerant sequentially passes through the on-off valve 16, the anti-freeze pipe 15, and converges with the first part of the refrigerant in the third pipe 63, and then sequentially passes through the outdoor heat exchanger 14, the expansion valve 33, the first indoor heat exchanger 32, the second switching port d of the four-way valve 13, and the outlet b of the four-way valve 13, and is finally sucked into the compressor 12 by the suction portion 122 of the compressor 12.

As a result, the part of the refrigerant discharged from the discharge portion 121 of the compressor 12 can quickly reach the chassis 112 of the outdoor heat exchanger 14, that is, a relatively high-temperature refrigerant is provided to melt the ice on the chassis 112, then converges with another part of the refrigerant in the third pipe 63 to enter the outdoor heat exchanger 14, so as to melt the frost on the outdoor heat exchanger 14, thereby quickly removing the frost on the outdoor heat exchanger 14 and the residual frost on the chassis 112.

In addition, in this embodiment, the control portion 50 switches the on-off valve 16 to the open state when starting the defrosting operation. As a result, the high-temperature refrigerant is allowed to efficiently flow into the anti-freeze pipe 15 by opening the on-off valve 16 when the compressor 12 restarts.

Furthermore, the control portion 50 switches the on-off valve 16 to the closed state when starting the heating operation. As a result, the hot refrigerant remains in the anti-freeze pipe 15 until the refrigerant cools down by closing the on-off valve 16 when the compressor 12 restarts, thus making full use of the remaining refrigerant.

FIG. 10 shows the flowchart of the air conditioner 100 in the heating operation.

In step S101, during the inaction period of the compressor 12, the control portion 50 determines whether receiving the starting operation instruction for the compressor 12. If the control portion 50 determines that the starting operation instruction for the compressor 12 has been received, the process proceeds to step S102. On the other hand, if the control portion 50 determines that the starting operation instruction for the compressor 12 has not been received, the process returns to step S101.

In this embodiment, the starting operation instruction for the compressor 12 is the instruction for the four-way valve 13 to be in the first state to drive the heating operation of the refrigeration cycle portion. This instruction is not only in the case of receiving the starting operation instruction from the remote controller 40 etc., but also in the case from a thermo-off (for example, when the temperature sensor detects that the room temperature had reached the target temperature, the operation of the compressor 12 has been stopped) to a thermo-on (for example, when the temperature sensor detects that the room temperature is away from the target temperature, the operation of the compressor 12 is started) based on detection results of the temperature sensor (not shown) arranged on 32.

In step S102, start the heating operation, and the on-off valve 16 is opened. Then the process proceeds to step S103.

Due to opening the on-off valve 16 at the same time as starting the heating operation in step S102, a part of the refrigerant can pass through the on-off valve 16 and the anti-freeze pipe 15, this can prevent the loss of refrigeration oil by recovering the refrigerant trapped in the pipes, thereby ensuring that the refrigeration, heating, and defrosting effects are fully utilized during the subsequent operation of the compressor 12.

In step S103, the control portion 50 determines whether the predetermined time has elapsed since the start of the heating operation. If the control portion 50 determines that the predetermined time has elapsed, the process proceeds to step S104. Otherwise, the process returns to step S103.

In step S104, the heating operation continues, and the on-off valve 16 is closed. Then the process proceeds to step S105.

In step S105, the control portion 50 determines whether a defrosting condition is satisfied. If the control portion 50 determines that the defrosting condition is satisfied, the process proceeds to step S106; otherwise, the process returns to step S105.

Here, whether the defrosting condition is satisfied can be determined, for example, by judging whether the predetermined time has elapsed since the start of the heating operation, or whether the temperature of the outdoor heat exchanger is lower than a predetermined temperature, etc., and it is not limited herein.

In step S106, the defrosting operation is started, and the on-off valve 16 is opened. Then the process proceeds to step S107.

In step S106, the heating operation ends, and the four-way valve 13 drives the defrosting operation of the refrigeration cycle portion in the refrigeration operation state. When performing the defrosting operation, the on-off valve 16 is switched to the open state.

In step S107, the control portion 50 determines whether a defrosting end condition is satisfied. If the control portion 50 determines that the defrosting end condition is satisfied, the process proceeds to step S108; otherwise, the process returns to step S107.

In this step, whether the defrosting end condition is satisfied can be determined, for example, by judging whether the temperature of the outdoor heat exchanger 14 is above a predetermined temperature, or whether the defrosting time has passed a predetermined time, etc., and it is not limited herein.

In step S108, the defrosting operation is ended, and the heating operation starts.

Then the process returns to step S105 to cyclically determine whether the defrosting operation is required.

Second Embodiment

The second embodiment of the present invention will be described in detail with reference to FIG. 11 to FIG. 14. In addition, for the convenience of description, the components having the same functions as those described in the above-mentioned embodiment are marked with the same reference numerals, and their descriptions are omitted.

The air conditioner 100A according to this embodiment is different from the air conditioner 100 according to the first embodiment in that the air conditioner 100A includes two indoor devices (a first indoor device and a second indoor device) and one outdoor heat exchanger. Specifically, for the structure of the first indoor device, the indoor heat exchanger 32 in the first embodiment serves as the first indoor heat exchanger of the second embodiment, the expansion valve 33 in the first embodiment serves as a first expansion valve of the second embodiment, the indoor fan 34 in the first embodiment serves as a first indoor fan of the second embodiment, and the indoor device housing in the first embodiment serves as a first indoor device housing of the second embodiment. The structure of the second indoor device further includes a second indoor heat exchanger 35, a second expansion valve 36, a second indoor fan 37, and a second indoor device housing. The second indoor device housing is configured to accommodate the second indoor fan 37 and the second indoor heat exchanger 35.

Specifically, the second indoor heat exchanger 35 is connected to the fourth pipe 64, which connects the first indoor heat exchanger 32 and the four-way valve 13, through the eighth pipe 68, and a ninth pipe 69 is connected to the fifth pipe 65 connecting the first indoor heat exchanger 32 and the outdoor heat exchanger 14. A connection point of the ninth pipe 69 and the fifth pipe 65 is located between the first expansion valve 33 and the outdoor heat exchanger 14.

The second expansion valve 36 is installed on the ninth pipe 69.

In this embodiment, the refrigeration cycle portion of the refrigeration cycle device is configured by sequentially connecting the compressor 12, the four-way valve 13, the outdoor heat exchanger 14, the first expansion valve 33, the first indoor heat exchanger 32, the second expansion valve 36, and the second indoor heat exchanger 35 through pipes. That is, the refrigeration cycle portion includes the compressor 12, the four-way valve 13, the outdoor heat exchanger 14, the first expansion valve 33, the first indoor heat exchanger 32, the second expansion valve 36, and the second indoor heat exchanger 35.

In this embodiment, the first indoor device and the second indoor device may operate simultaneously or only one of the indoor devices operates. The refrigeration operation, the heating operation, and the defrosting operation of each of the first indoor device and the second indoor device are same as those of the first embodiment. The heating operation and the defrosting operation are taken as examples for description below.

Referring to FIG. 12, which shows a situation when the air conditioner 100A of this embodiment is in normal operation, that is, when both the first expansion valve 33 and the second expansion valve 36 are normally opened, that is, when the two indoor devices operate simultaneously.

Referring to FIG. 12. during performing the heating operation, the control portion 50 controls the four-way valve 13 to operate, and the refrigerant discharged from the discharge portion 121 of the compressor 12 passes through the inlet a of the four-way valve 13 and the second switching port d of the four-way valve 13, then flows into the fourth pipe 64. In the fourth pipe 64, a part of the refrigerant continues to flow along the fourth pipe 64, the first indoor heat exchanger 32, the first expansion valve 33, the outdoor heat exchanger 14, the first switching port c of the four-way valve 13, and the outlet b of the four-way valve 13, and is finally sucked into the compressor 12 by the suction portion 122 of the compressor 12. In the fourth pipe 64, another part of the refrigerant flows along the eighth pipe 68, the second indoor heat exchanger 35, the second expansion valve 36, the outdoor heat exchanger 14, the first switching port c of the four-way valve 13, and the outlet b of the four-way valve 13, and is finally sucked into the compressor 12 by the suction portion 122 of the compressor 12, so as to complete the heating cycle and repeat the heating cycle.

Referring to FIG. 13. during the defrosting operation, the control portion 50 controls the four-way valve 13 to operate. After the first part of the refrigerant discharged from the discharge portion 121 of the compressor 12 sequentially passes through the inlet a of the four-way valve 13, the first switching port c of the four-way valve 13, and the outdoor heat exchanger 14, a part of the first part of the refrigerant sequentially passes through the fifth pipe 65, the first expansion valve 33, the first indoor heat exchanger 32, the second switching port d of the first four-way valve 13, and the outlet b of the four-way valve 13, and is finally sucked into the compressor 12 by the suction portion 122 of the compressor 12, another part of the first part of the refrigerant sequentially passes through the fifth pipe 65, the ninth pipe 69, the second expansion valve 36, the second indoor heat exchanger 35, the eighth pipe 68, and converges with this part of the refrigerant, then passes through the second switching port d of the first four-way valve 13 and the outlet b of the four-way valve 13, and is finally sucked into the compressor 12 by the suction portion 122 of the compressor 12. The second part of the refrigerant sequentially passes through the on-off valve 16, the anti-freeze pipe 15, and converges with the first part of the refrigerant in the third pipe 63, then sequentially passes through the outdoor heat exchanger 14, the expansion valve 33, the first indoor heat exchanger 32, the second switching port d of the four-way valve 13, and the outlet b of the four-way valve 13, and is finally sucked into the compressor 12 by the suction portion 122 of the compressor 12.

Referring to FIG. 14, when only one indoor device is started, that is, the heating operation is performed while the second expansion valve 36 is closed, after the refrigerant discharged from the exhaust port of the compressor 12 passes through the inlet a of the four-way valve 13 and the second switching port d of the four-way valve 13, a part of the refrigerant continues to flow along the fourth pipe 64, the first indoor heat exchanger 32, the first expansion valve 33, the outdoor heat exchanger 14, the first switching port c of the four-way valve 13, and the outlet b of the four-way valve 13, and is finally sucked into the compressor 12 by the suction portion 122 of the compressor 12.

In this embodiment, even if one of the expansion valves is closed, the defrosting operation is not affected. That is, in the case that one of the expansion valves is in the closed state, when the defrosting operation is required, the defrosting operation is still performed according to the way of the defrosting operation shown in FIG. 13.

In this embodiment, although it is shown that based on the air conditioner 100 according to the first embodiment, it is further provided with the second indoor heat exchanger 35, the second expansion valve 36, the second indoor fan 37, and the second indoor device housing. However, in other embodiments, it may further be provided with a third indoor heat exchanger 35, a third expansion valve 36, a third indoor fan 37, and a third indoor device housing, etc., and it is not limited herein.

Modification of the Second Embodiment

Although in the first embodiment and the second embodiment, it is shown that the pipe connecting the on-off valve 16 is connected to the first pipe 61 connecting the compressor 12 and the inlet a of the four-way valve 13. However, in the outdoor air conditioner 100B of the modification, as shown in FIG. 15, one end of the sixth pipe 66 is connected to the anti-freeze pipe 15, and the other end of the sixth pipe 66 is connected to the third pipe 63 that connects the outdoor heat exchanger 14 and the second switching port c of the four-way valve 13. The other components are the same as those of the second embodiment, and will not be described in detail here.

In this modification, although it is shown that the modification is based on the structure of the air conditioner 100A according to the second embodiment, it can also be based on the structure of the air conditioner 100 according to the first embodiment, and is not limited herein.

The embodiments of the present invention are illustrated in all aspects and should not be considered as limitations. The scope of the present invention is represented not by the above description but by the scope of the claims, and is intended to include all meanings equivalent to the scope of the claims and all changes within the scope. Moreover, the structures obtained by combining the components of different embodiments described in this specification with each other are included in the scope of the present invention.

REFERENCE SIGNS LIST

• • 100, 100A, 100B: Outdoor air conditioner
  • 10: Outdoor device
  • 11: Outdoor device housing
  • 112: chassis
  • 12: Compressor
  • 121: Discharge portion
  • 122: Suction portion
  • 13: Four-way valve
  • 14: Outdoor heat exchanger
  • 15: Anti-freeze pipe
  • 16: On-off valve
  • 17: Outdoor fan
  • 18: First temperature sensor
  • 19: Second temperature sensor
  • 30: Indoor device
  • 32: Indoor heat exchanger (First indoor heat exchanger)
  • 33: Expansion valve (First expansion valve)
  • 34: Indoor fan (First indoor fan)
  • 35: Second indoor heat exchanger
  • 36: Second expansion valve
  • 37: Second indoor fan
  • 40: Remote controller
  • 50: Control portion
  • 51: Storage portion
  • 52: Communication portion
  • 55: Judgment portion
  • 56: Counting portion
  • 61: First pipe
  • 62: Second pipe
  • 63: Third pipe
  • 64: Fourth pipe
  • 65: Fifth pipe
  • 66: Sixth pipe
  • 67: Seventh pipe
  • 68: Eighth pipe
  • 69: Ninth pipe