Outdoor unit of air conditioner, and air conditioner

Abstract

An outdoor unit (10) of an air conditioner (1) is provided with: a housing (10a); a compressor (11) that is disposed within the housing (10a) and compresses a flammable refrigerant; an outdoor heat exchanger (13) that is disposed within the housing (10a), that is connected to the compressor (11) via refrigerant piping (40) through which the flammable refrigerant circulates, and that exchanges heat between the flammable refrigerant and air; an outdoor electrical component box (16) that is disposed above the compressor (11) within the housing (10a); a refrigerant detection sensor (30a) that is installed outside of the outdoor electrical component box (16) and that detects leakage of the flammable refrigerant; and an outdoor control device (50) that is disposed in the interior of the outdoor electrical component box (16), that is constituted by a plurality of electronic components, and that stops operation of the electronic components which have movable parts from among the electronic components when the refrigerant detection sensor (30a) has detected leakage of the flammable refrigerant.

Description

Outdoor unit of air conditioner, and air conditioner

[0001] The present disclosure relates to an air conditioner that uses a flammable refrigerant.

[0002] In conventional air conditioners that use flammable refrigerants, refrigerant detection sensors are provided in the indoor and outdoor units to prevent fires in the event of a refrigerant leak from the indoor unit. Techniques have been disclosed, such as issuing an alarm or driving fans provided in the indoor and outdoor units to diffuse the refrigerant and reduce its concentration, depending on the detection value of the refrigerant detection sensor (see, for example, Patent Document 1).

[0003] JP 2016-70594 A

[0004] The indoor and outdoor units of air conditioners are equipped with a control device that controls the various components, such as the fans and compressors, required for heating and cooling operation. The control device is an electronic board on which multiple electronic components are mounted, including those with moving parts, such as electromagnetic switches and relays.

[0005] Electronic components with moving parts can generate fires when they move. If a flammable refrigerant leaks and generates a fire when the refrigerant concentration is high, there is a risk that the leaked refrigerant will ignite.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an outdoor unit for an air conditioner that can prevent refrigerant from igniting when a refrigerant leak is detected.

[0007] The outdoor unit of the air conditioner according to the present disclosure comprises a housing, a compressor disposed within the housing for compressing a flammable refrigerant, an outdoor heat exchanger disposed within the housing and connected to the compressor via a refrigerant pipe through which the flammable refrigerant flows and for exchanging heat between the flammable refrigerant and air, an outdoor electrical equipment box disposed above the compressor within the housing, a refrigerant detection sensor installed outside the outdoor electrical equipment box for detecting leakage of the flammable refrigerant, and an outdoor control device disposed inside the outdoor electrical equipment box and composed of a plurality of electronic components, which stops the operation of electronic components having moving parts among the electronic components when the refrigerant detection sensor detects leakage of the flammable refrigerant.

[0008] According to the present disclosure, when a refrigerant leak is detected in an outdoor unit, the operation of electronic components having moving parts can be stopped to prevent the refrigerant from catching fire.

[0009] FIG. 1 is a configuration diagram of an air conditioner 1 according to embodiment 1. FIG. 2 is a front view showing a schematic internal structure of the outdoor unit 10 of the air conditioner 1 according to embodiment 1. FIG. 3 is a block diagram showing the functional configuration of the outdoor control device 50 and the indoor control device 60 according to embodiment 1. FIG. 4 is a flowchart showing refrigerant leak detection processing in the air conditioner 1 according to embodiment 1. FIG. 5 is a configuration diagram of an air conditioner 1 according to embodiment 2. FIG. 6 is a block diagram showing the functional configuration of the outdoor control device 50 and the indoor control device 60 according to embodiment 2. FIG. 7 is a flowchart showing refrigerant leak detection processing in the air conditioner 1 according to embodiment 2. FIG. 8 is a configuration diagram of an air conditioner 1 according to embodiment 3. FIG. 9 is a block diagram showing the functional configuration of the outdoor control device 50 and the indoor control device 60 according to embodiment 3. FIG. 10 is a flowchart showing refrigerant leak detection processing in the outdoor unit 10 of the air conditioner 1 according to embodiment 3. FIG. 11 is a flowchart showing refrigerant leak detection processing in the indoor unit 20 of the air conditioner 1 according to embodiment 3.

[0010] The following description will discuss embodiments of the present disclosure with reference to the accompanying drawings. In each drawing, identical or corresponding parts are designated by the same reference numerals, and redundant descriptions are appropriately simplified or omitted. The present disclosure is not limited to the following embodiments, and any of the components of the embodiments may be modified, combined, or omitted without departing from the spirit of the present disclosure.

[0011] Embodiment 1. Fig. 1 is a configuration diagram of an air conditioner 1 according to embodiment 1 of the present disclosure. Solid arrows shown in Fig. 1 indicate the flow of refrigerant during cooling operation. Dashed arrows shown in Fig. 1 indicate the flow of refrigerant during heating operation. Fig. 2 is a front view schematically showing the internal structure of the outdoor unit of the air conditioner 1 according to embodiment 1 of the present disclosure. With reference to Figs. 1 and 2, an air conditioner in which an outdoor unit 10 and an indoor unit 20 are connected via refrigerant piping 40 consisting of gas refrigerant piping 40a and liquid refrigerant piping 40b will be described as an example of this embodiment.

[0012] The outdoor unit 10 includes a box-shaped housing 10a, which houses a compressor 11, a four-way valve 12, an outdoor heat exchanger 13, an expansion valve 14, an outdoor fan 15, an outdoor electrical equipment box 16, and a refrigerant detection sensor 30a. The interior space of the housing 10a is divided by a separator 17 into a machine chamber 18 and an air blower chamber 19. The machine chamber 18 houses the compressor 11, the four-way valve 12, the expansion valve 14, and the outdoor electrical equipment box 16. The air blower chamber 19 houses the outdoor heat exchanger 13 and the outdoor fan 15. An outdoor control device 50 that controls the compressor 11, the four-way valve 12, and the outdoor fan 15 is provided inside the outdoor electrical equipment box 16.

[0013] The indoor unit 20 includes an indoor heat exchanger 21, an indoor fan 22, and an indoor electrical equipment box 23. The indoor electrical equipment box 23 also includes an indoor control device 60 that controls the indoor fan 22 and communicates with the outdoor control device 50.

[0014] The refrigerant circuit of the air conditioner 1 is composed of a compressor 11, a four-way valve 12, an outdoor heat exchanger 13, an expansion valve 14, and an indoor heat exchanger 21, which are connected in sequence by refrigerant piping 40. The refrigerant piping 40 has a gas refrigerant piping 40a through which gaseous refrigerant flows, and a liquid refrigerant piping 40b through which liquid refrigerant flows. The outdoor unit 10 and the indoor unit 20 are connected by the gas refrigerant piping 40a and the liquid refrigerant piping 40b.

[0015] The refrigerant circuit is configured such that during cooling operation, the refrigerant circulates in the order of the compressor 11, four-way valve 12, outdoor heat exchanger 13, expansion valve 14, indoor heat exchanger 21, and four-way valve 12. During heating operation, the refrigerant circuit is configured such that the refrigerant circulates in the order of the compressor 11, four-way valve 12, indoor heat exchanger 21, expansion valve 14, outdoor heat exchanger 13, and four-way valve 12.

[0016] The refrigerant circulating in the refrigerant circuit is a flammable refrigerant such as R290.

[0017] The compressor 11 compresses the refrigerant it draws in, and discharges it in a high-temperature, high-pressure state. The compressor 11 is, for example, a positive displacement compressor with a variable operating capacity that is driven by a motor controlled by an inverter. The compressor 11 is disposed in contact with the bottom surface of the housing 10a of the outdoor unit 10, as shown in FIG. 2 .

[0018] The four-way valve 12 has a function of switching the refrigerant flow path. During cooling operation, the four-way valve 12 connects the refrigerant discharge side of the compressor 11 to the refrigerant piping 40 connected to the outdoor heat exchanger 13, and also connects the refrigerant suction side of the compressor 11 to the refrigerant piping 40 connected to the indoor heat exchanger 21. On the other hand, during heating operation, the four-way valve 12 connects the refrigerant discharge side of the compressor 11 to the refrigerant piping 40 connected to the indoor heat exchanger 21, and also connects the refrigerant suction side of the compressor 11 to the refrigerant piping 40 connected to the outdoor heat exchanger 13.

[0019] The outdoor heat exchanger 13 is configured to exchange heat between the refrigerant flowing inside the outdoor heat exchanger 13 and the air flowing outside the outdoor heat exchanger 13. The outdoor heat exchanger 13 is configured to function as a condenser that condenses the refrigerant during cooling operation, and as an evaporator that evaporates the refrigerant during heating operation.

[0020] The expansion valve 14 reduces the pressure of the refrigerant condensed by the condenser by expanding it, and is, for example, an electronic expansion valve whose opening is variably controlled. The expansion valve 14 reduces the pressure of the refrigerant condensed by the outdoor heat exchanger 13 during cooling operation, and reduces the pressure of the refrigerant condensed by the indoor heat exchanger 21 during heating operation.

[0021] The indoor heat exchanger 21 is configured to exchange heat between the refrigerant flowing inside the indoor heat exchanger 21 and the air flowing outside the indoor heat exchanger 21. The indoor heat exchanger 21 is configured to function as a condenser that condenses the refrigerant during heating operation, and as an evaporator that evaporates the refrigerant during cooling operation.

[0022] The outdoor fan 15 is disposed near the outdoor heat exchanger 13. It draws air in through an air inlet (not shown) in the housing 10a and exchanges heat between the air and the outdoor heat exchanger 13. The outdoor fan 15 then blows the air that has exchanged heat with the outdoor heat exchanger 13 out through an air outlet (not shown) in the housing 10a. In other words, the outdoor fan 15 is configured to generate an airflow that passes through the outdoor heat exchanger 13.

[0023] The indoor fan 22 is disposed near the indoor heat exchanger 21 and configured to blow indoor air to the indoor heat exchanger 21. In other words, the indoor fan 22 is configured to supply air to the indoor heat exchanger 21.

[0024] The outdoor electrical equipment box 16 houses the outdoor control device 50, which controls the rotation speed of the motors that drive the compressor 11 and the outdoor fan 15, the switching of the four-way valve 12, the opening of the expansion valve 14, etc. The outdoor control device 50 includes an electronic circuit board on which electronic components such as a microcomputer and a relay are mounted. The outdoor control device 50 also includes an electromagnetic contactor that conducts the power supply circuit and an electromagnetic contactor used to control the motors that drive the compressor 11 and the outdoor fan 15. When electronic components with moving parts, such as relays and electromagnetic contactors, move, an arc discharge occurs the moment the contact points come into contact, generating a spark that may become an ignition source.

[0025] The refrigerant detection sensor 30a detects the refrigerant concentration in the air and, when the refrigerant concentration exceeds a threshold, sends a refrigerant leak detection signal indicating a refrigerant leak to the outdoor control device 50. The refrigerant detection sensor 30a is located inside the housing 10a of the outdoor unit 10, outside the outdoor electrical equipment box 16. This allows refrigerant leaking from the refrigerant piping 40 to be detected when it flows near the outdoor electrical equipment box 16 before it enters the interior of the outdoor electrical equipment box 16. Furthermore, because flammable refrigerants have a higher density than air, leaking refrigerant flows downward and accumulates below the housing 10a, so it is desirable to install the refrigerant detection sensor 30a on the exterior, lower surface or lower side of the outdoor electrical equipment box 16.

[0026] Furthermore, the refrigerant detection sensor 30a may be installed between a location where refrigerant leakage is likely to occur and the outdoor electrical equipment box 16. Locations where refrigerant leakage is likely to occur include the joint between the compressor and a liquid pipe or a gas pipe, a U-bend in the heat exchanger, and joints of the refrigerant piping 40. The outdoor electrical equipment box 16 is located in the machine room 18 above the compressor 11, the expansion valve 14, and the refrigerant piping 40 connecting them. Therefore, by locating the refrigerant detection sensor 30a above the compressor 11, the expansion valve 14, and the refrigerant piping 40 connecting them, but below the outdoor electrical equipment box 16, refrigerant leaking from the refrigerant piping 40 can be detected before it flows into the outdoor electrical equipment box 16.

[0027] FIG. 3 is a block diagram showing the functional configuration of the outdoor control device 50 and the indoor control device 60 according to the first embodiment. The outdoor control device 50 includes an outdoor control unit 51, an outdoor power supply circuit 52, an outdoor communication unit 53, a compressor control unit 54, and an outdoor fan control unit 55. The outdoor control unit 51 controls the compressor 11, the four-way valve 12, the outdoor fan 15, and the expansion valve 14 and receives a detection signal from the refrigerant detection sensor 30a. The outdoor control unit 51 also includes at least one processor and at least one memory. The processor is also referred to as a CPU (Central Processing Unit), processing device, arithmetic unit, microprocessor, microcomputer, or DSP. The memory includes, for example, non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, and EEPROM. The outdoor power supply circuit 52 controls the power supply to the outdoor control device 50. The outdoor communication unit 53 communicates with the indoor control device 60 via wired or wireless communication. The compressor control unit 54 includes a component that controls the compressor 11 and an inverter circuit that supplies voltage to the compressor 11. The outdoor fan control unit 55 includes a component that controls the outdoor fan 15 and an inverter circuit that supplies voltage to the outdoor fan 15. The components are configured by software, firmware, or a combination of software and firmware.

[0028] The compressor control unit 54, the outdoor fan control unit 55, and the outdoor power supply circuit 52 include electronic components with moving parts, such as relays and electromagnetic contactors. Electronic components with moving parts may generate a fire when they move, and if a fire is generated in an environment with a high concentration of flammable refrigerant, the flammable refrigerant may ignite.

[0029] The indoor control device 60 includes an indoor control unit 61, an indoor power supply circuit 62, an indoor communication unit 63, and an indoor fan control unit 64. The indoor power supply circuit 62 receives power from the power grid 70 and controls the power supply of the indoor control device 60. The indoor power supply circuit 62 also supplies power to the outdoor power supply circuit 52. The indoor control unit 61 controls the indoor fan. The indoor control unit 61 and the indoor communication unit 63 also communicate with the outdoor control device 50. The indoor fan control unit 64 includes a component that controls the indoor fan 22 and an inverter circuit that supplies voltage to the indoor fan 22. The indoor control unit 61 can also send a signal to an alarm means 24 located outside the indoor unit 20 to alert users to abnormalities such as refrigerant leakage. The alarm means 24 is a remote control device used to control the air conditioner 1. Alternatively, the alarm means 24 may be a smartphone or tablet terminal. The alarm provided by the alarm means 24 is an audible warning or voice message. Alternatively, the notification by the notification means 24 may be visual, such as by flashing a light source or displaying text on a display screen.

[0030] 4 is a flowchart showing the refrigerant leakage detection process in the air conditioner 1 according to Embodiment 1 of the present disclosure. With reference to FIG. 4, the operation of the air conditioner 1 when the refrigerant detection sensor 30a detects a refrigerant leakage will be described.

[0031] When the air conditioner 1 is powered on, the refrigerant leak detection process begins. First, in step S101, the outdoor control unit 51 determines whether or not a refrigerant leak detection signal has been received from the refrigerant detection sensor 30a. If a refrigerant leak detection signal has been received (Yes in step S101), the process proceeds to step S102. Here, because the refrigerant detection sensor 30a is located outside the outdoor electrical equipment box 16, the refrigerant detection sensor 30a can detect leaked refrigerant before it flows into the outdoor electrical equipment box 16. If a refrigerant leak detection signal has not been received (No in step S101), the process returns to step S101.

[0032] In step S102, the outdoor control unit 51 stops the operation of electronic components with moving parts included in the outdoor control device 50. Stopping the operation means not switching relays, electromagnetic switches, etc. Specifically, the outdoor control unit 51 maintains the current output for switching relays, electromagnetic switches, etc. This prevents a spark from being generated inside the outdoor electrical equipment box 16 and the leaked refrigerant from igniting. Next, proceed to step S103.

[0033] In step S103, the outdoor control unit 51 notifies the indoor communication unit 63 via the outdoor communication unit 53 that a refrigerant leak has occurred in the outdoor unit 10. At this time, the outdoor control device 50 has stopped operating electronic components having moving parts, but the outdoor control device 50 as a whole has not stopped, so the outdoor communication unit 53 is still functioning. Next, the process proceeds to step S104.

[0034] In step S104, the indoor control unit 61 receives information about a refrigerant leak in the outdoor unit 10 via the indoor communication unit 63, and causes the notification means 24 to notify the user of the refrigerant leak. The notification means 24 notifies the user of the refrigerant leak by voice or screen display, etc. Next, the process proceeds to step S105.

[0035] In step S105, the indoor control unit 61 controls the indoor power supply circuit 62 to cut off the power supply to the outdoor unit 10. This stops the operation of the refrigerant circuit of the air conditioner 1, and the refrigerant leak detection process ends.

[0036] Furthermore, since it is necessary to identify and repair the location of the refrigerant leak before the air conditioner 1 is next operated, it is desirable to also notify the user that repair is required when issuing the notification in step S104.

[0037] Through the above process, the refrigerant detection sensor 30a detects a refrigerant leak before it flows into the outdoor electrical equipment box 16, and by stopping the operation of the electronic components with moving parts in the outdoor control device 50, no spark is generated inside the outdoor electrical equipment box 16 and the leaked refrigerant does not ignite. Furthermore, because the outdoor control device 50 can communicate with the indoor control device 60 while the operation of the electronic components with moving parts is stopped, the user can be notified of the refrigerant leak via the indoor control device 60.

[0038] As described above, the outdoor unit 10 of the air conditioner 1 of the present disclosure comprises a housing 10a, a compressor 11 disposed within the housing 10a and compressing a flammable refrigerant, an outdoor heat exchanger 13 disposed within the housing 10a and connected to the compressor 11 via a refrigerant pipe 40 through which the flammable refrigerant flows and exchanging heat between the flammable refrigerant and air, an outdoor electrical equipment box 16 disposed within the housing 10a above the compressor 11, a refrigerant detection sensor 30a installed outside the outdoor electrical equipment box 16 and detecting leakage of the flammable refrigerant, and an outdoor control device 50 disposed within the outdoor electrical equipment box 16 and comprising a plurality of electronic components, which stops operation of electronic components having moving parts when the refrigerant detection sensor 30a detects leakage of the flammable refrigerant.

[0039] With this configuration, even if a leaking flammable refrigerant flows into the outdoor electrical equipment box 16, electronic components with moving parts that could be an ignition source will not be operated, thereby preventing the flammable refrigerant from igniting.

[0040] Alternatively, the refrigerant detection sensor 30a may be disposed on the outer surface of the outdoor electrical equipment box 16. With this configuration, the refrigerant detection sensor 30a can detect that the leaking flammable refrigerant has flowed into the vicinity of the outdoor electrical equipment box 16 before entering the outdoor electrical equipment box 16.

[0041] The interior of the housing 10a is divided into a machine chamber 18 in which the compressor 11 and the outdoor electrical equipment box 16 are disposed, and an air blower chamber 19 in which the outdoor heat exchanger 13 is disposed, and the refrigerant detection sensor 30a may be disposed above the compressor 11 in the machine chamber 18 and below the outdoor electrical equipment box 16. With this configuration, the refrigerant detection sensor 30a is disposed between a location where refrigerant is likely to leak and the outdoor electrical equipment box 16, and can detect leaked flammable refrigerant before it flows into the vicinity of the outdoor electrical equipment box 16.

[0042] In addition, the air conditioner 1 of the present disclosure comprises an outdoor unit, an indoor unit 20 having an indoor control device 60 that receives a refrigerant leak notification from the outdoor control device 50 indicating that a flammable refrigerant leak has been detected in the outdoor unit 10, and an alarm means 24 that is communicatively connected to the indoor control device 60 and alerts the user, and when the indoor control device 60 receives the refrigerant leak notification, it causes the alarm means 24 to alert the user that a refrigerant has leaked.

[0043] With this configuration, even if the operation of electronic components having moving parts in the outdoor control device 50 is stopped, a refrigerant leak notification can be sent to the indoor control device 60, and the indoor control device 60 can have the alarm means 24 alert the user to the refrigerant leak.

[0044] Second Embodiment Next, a second embodiment will be described with reference to the drawings. Fig. 5 is a configuration diagram of an air conditioner according to the second embodiment. Fig. 6 is a block diagram showing the functional configuration of an outdoor control device 50 and an indoor control device 60 according to the second embodiment. Note that a description of the same parts of this embodiment as those of the above-mentioned embodiments will be omitted.

[0045] In the second embodiment, as shown in Fig. 5, the outdoor unit 10 is provided with a second refrigerant detection sensor 30b on its lower part. As shown in Fig. 6, the second refrigerant detection sensor 30b is connected so as to be able to communicate with an outdoor control unit 51 provided in the outdoor control device 50 inside the outdoor electrical equipment box 16. The second refrigerant detection sensor 30b detects the refrigerant concentration in the air, and when the refrigerant concentration exceeds a threshold value, sends a refrigerant leak detection signal indicating a refrigerant leak to the outdoor control unit 51 provided in the outdoor control device 50.

[0046] Flammable refrigerant has a higher density than air. Therefore, refrigerant that leaks inside the outdoor unit 10 accumulates at the bottom. By providing the second refrigerant detection sensor 30b at the bottom inside the housing 10a of the outdoor unit 10, it can detect refrigerant that leaks inside the outdoor unit 10 earlier than the refrigerant detection sensor 30a. Specifically, the second refrigerant detection sensor 30b is preferably provided below the compressor 11, expansion valve 14, outdoor heat exchanger 13, and refrigerant piping 40 connecting them, through which the flammable refrigerant flows.

[0047] Fig. 7 is a flowchart showing the refrigerant leak detection process in the air conditioner 1 according to Embodiment 2. The refrigerant leak detection process in the air conditioner 1 will be described with reference to Fig. 7 .

[0048] When the air conditioner 1 is powered on, the refrigerant leak detection process begins. First, in step S201, the outdoor control unit 51 determines whether or not a refrigerant leak detection signal is present from the refrigerant detection sensor 30a. If a refrigerant leak detection signal is present (Yes in step S201), the process proceeds to step S202. Here, because the refrigerant detection sensor 30a is located near the outside of the outdoor electrical equipment box 16, the refrigerant detection sensor 30a can detect a refrigerant leak before the leaked refrigerant flows into the outdoor electrical equipment box 16. The case where the result in step S201 is Yes will be described.

[0049] In step S202, the outdoor control unit 51 stops the operation of electronic components with moving parts included in the outdoor control device 50. Stopping the operation means not switching relays, electromagnetic switches, etc. Specifically, the outdoor control unit 51 maintains the current output for switching relays, electromagnetic switches, etc. This prevents a spark from being generated inside the outdoor electrical equipment box 16 and the leaked refrigerant from igniting. Next, proceed to step S203.

[0050] In step S203, the outdoor control unit 51 notifies the indoor communication unit 63 via the outdoor communication unit 53 that a refrigerant leak has occurred in the outdoor unit 10. At this time, the outdoor control device 50 has stopped operating electronic components having moving parts, but the outdoor control device 50 as a whole has not stopped, so the outdoor communication unit 53 is still functioning. Next, the process proceeds to step S204.

[0051] In step S204, the indoor control unit 61 receives information about a refrigerant leak in the outdoor unit 10 via the indoor communication unit 63, and causes the notification means 24 to notify the user of the refrigerant leak. The notification means 24 notifies the user of the refrigerant leak by voice or screen display, etc. Next, the process proceeds to step S205.

[0052] In step S205, the indoor control unit 61 controls the indoor power supply circuit 62 to cut off the power supply to the outdoor unit 10. This stops the operation of the refrigerant circuit of the air conditioner 1, and the refrigerant leak detection process ends.

[0053] Next, a description will be given of the case where there is no refrigerant leakage detection signal in step S201 (No in step S201). If there is no refrigerant leakage detection signal in step S201, the process proceeds to step S206.

[0054] In step S206, the outdoor control unit 51 determines whether or not a refrigerant leak detection signal has been received from the second refrigerant detection sensor 30b. If no refrigerant leak detection signal has been received (No in step S206), the process returns to step S201. If a refrigerant leak detection signal has been received from the second refrigerant detection sensor 30b (Yes in step S206), the process proceeds to step S207. Here, the second refrigerant detection sensor 30b is located at the bottom of the housing 10a of the outdoor unit 10. Flammable refrigerant has a density greater than that of air and flows downward from the leaked location. Therefore, even a small amount of leaked refrigerant will flow to the bottom of the housing 10a and be detected by the second refrigerant detection sensor 30b.

[0055] In step S207, the outdoor control unit 51 drives the outdoor fan 15. Step S207 is performed when there is no refrigerant leak detection signal from the refrigerant detection sensor 30a, but there is a refrigerant leak detection signal from the second refrigerant detection sensor 30b. In other words, the refrigerant has not flowed into the outdoor electrical equipment box 16, and is present in the lower part of the housing 10a of the outdoor unit 10. By driving the outdoor fan 15, the refrigerant accumulated in the lower part of the housing 10a can be dispersed to the outside of the housing 10a. Next, the process proceeds to step S208.

[0056] In step S208, it is determined whether a refrigerant leak detection signal is received from the second refrigerant detection sensor 30b for a certain period of time. If a refrigerant leak detection signal is received from the second refrigerant detection sensor 30b (No in step S208), refrigerant remains in the lower part of the housing 10a, so the process returns to step S207 and continues driving the outdoor fan 15. If a refrigerant leak detection signal is not received from the second refrigerant detection sensor 30b for a certain period of time (Yes in step S208), the refrigerant accumulated in the lower part of the housing 10a has been blown out of the housing 10a. If a refrigerant leak detection signal is not received from the second refrigerant detection sensor 30b for a certain period of time, the process proceeds to step S203. The processes in steps S203 to S205 are as described above and will be omitted here.

[0057] As described above, a refrigerant leak is detected by the refrigerant detection sensor 30a, which detects the refrigerant leak before it flows into the outdoor electrical equipment box 16, and the second refrigerant detection sensor 30b, which detects the refrigerant accumulated in the lower part of the housing 10a, and the processing is changed depending on the location of the refrigerant leak. If the refrigerant does not flow into the outdoor electrical equipment box 16 but is present in the lower part of the housing 10a of the outdoor unit 10, the accumulated refrigerant is dispersed outside the housing 10a, thereby preventing the refrigerant from igniting.

[0058] As described above, the outdoor unit 10 of the air conditioner 1 of the present disclosure comprises a housing 10a, a compressor 11 disposed within the housing 10a and compressing a flammable refrigerant, an outdoor heat exchanger 13 disposed within the housing 10a and connected to the compressor 11 via a refrigerant pipe 40 through which the flammable refrigerant flows and exchanging heat between the flammable refrigerant and air, an outdoor electrical equipment box 16 disposed within the housing 10a above the compressor 11, a refrigerant detection sensor 30a installed outside the outdoor electrical equipment box 16 and detecting a flammable refrigerant leak, and an outdoor control device 50 disposed within the outdoor electrical equipment box 16 and comprising a plurality of electronic components that, if the refrigerant detection sensor 30a detects a flammable refrigerant leak, stops the operation of those electronic components that have moving parts, and further comprises a second refrigerant detection sensor 30b disposed within the housing 10a below the refrigerant detection sensor 30a for detecting a flammable refrigerant leak. With this configuration, refrigerant leaking to the lower part of the housing 10 a of the outdoor unit 10 can be detected.

[0059] The outdoor unit 10 is further provided with an outdoor fan 15 disposed within the housing 10a that generates an airflow that passes through the outdoor heat exchanger 13, and the outdoor control device 50 drives the outdoor fan 15 when the refrigerant detection sensor 30a does not detect a flammable refrigerant leak and the second refrigerant detection sensor 30b detects a flammable refrigerant leak. With this configuration, when refrigerant leaks within the outdoor unit 10 but the leaked refrigerant has not yet flowed into the outdoor electrical equipment box 16, safety can be ensured by driving the outdoor fan 15 to disperse the leaked refrigerant outside the housing 10a.

[0060] Third Embodiment Next, a third embodiment will be described with reference to the drawings. Fig. 8 is a configuration diagram of an air conditioner 1 according to the third embodiment. Fig. 9 is a block diagram showing the functional configuration of an outdoor control device 50 and an indoor control device 60 according to the third embodiment. Note that a description of the same parts of this embodiment as those of the above-mentioned embodiments will be omitted.

[0061] In the third embodiment, as shown in Fig. 8, the indoor unit 20 is equipped with an indoor refrigerant detection sensor 30c. As shown in Fig. 9, the indoor refrigerant detection sensor 30c is connected so as to be able to communicate with an indoor control unit 61 provided in the indoor control device 60 inside the indoor electrical equipment box 23. The indoor refrigerant detection sensor 30c detects the refrigerant concentration in the air, and when the refrigerant concentration exceeds a threshold value, sends a refrigerant leak detection signal indicating a refrigerant leak to the indoor control unit 61 provided in the indoor control device 60.

[0062] Figure 10 is a flowchart showing refrigerant leak detection processing in the outdoor unit 10 of an air conditioner 1 according to Embodiment 3. Figure 11 is a flowchart showing refrigerant leak detection processing in the indoor unit 20 of an air conditioner 1 according to Embodiment 3. In this embodiment, the indoor refrigerant detection sensor 30c arranged inside the indoor unit 20 is connected to be able to communicate with the indoor control device 60. Therefore, refrigerant leak detection processing is performed by the outdoor control device 50, which receives the refrigerant leak detection signal from the refrigerant detection sensor 30a, and the indoor control device 60, which receives the refrigerant leak detection signal from the indoor refrigerant detection sensor 30c. The refrigerant leak detection processing of the air conditioner 1 will be described with reference to Figures 10 and 11 .

[0063] First, the refrigerant detection process in the outdoor unit 10 will be described with reference to Figure 10. In step S301, the outdoor control unit 51 determines whether or not a refrigerant leak detection signal has been received from the refrigerant detection sensor 30a. If a refrigerant leak detection signal has been received (Yes in step S301), the process proceeds to step S302. Here, because the refrigerant detection sensor 30a is located outside the outdoor electrical equipment box 16, the refrigerant detection sensor 30a can detect leaking refrigerant before it enters the outdoor electrical equipment box 16. If a refrigerant leak detection signal has not been received (No in step S301), the process returns to step S301.

[0064] In step S302, the outdoor control unit 51 stops the operation of electronic components having moving parts included in the outdoor control device 50. Stopping the operation means not switching relays, electromagnetic switches, etc. Specifically, the outdoor control unit 51 maintains the current output for switching relays, electromagnetic switches, etc. This prevents a spark from being generated inside the outdoor electrical equipment box 16 and the leaked refrigerant from igniting. Next, proceed to step S303.

[0065] In step S303, the outdoor control unit 51 notifies the indoor communication unit 63 via the outdoor communication unit 53 that a refrigerant leak has occurred in the outdoor unit 10. At this time, the operation of electronic components having moving parts in the outdoor control device 50 has stopped, but the outdoor communication unit 53 is still functioning because the outdoor control device 50 as a whole has not stopped. This completes the refrigerant detection process in the outdoor unit 10.

[0066] Next, the refrigerant detection process in the indoor unit 20 will be described with reference to Figure 11. In step S401, the indoor control unit 61 determines whether the indoor communication unit 63 has received a refrigerant leak notification from the outdoor unit 10. If there has been a refrigerant leak notification from the outdoor unit 10 (Yes in step S401), the process proceeds to step S402. If there has not been a refrigerant leak notification from the outdoor unit 10 (No in step S401), the process proceeds to step S406.

[0067] In step S402, the indoor control unit 61 determines whether or not a refrigerant leakage detection signal has been received from the indoor refrigerant detection sensor 30c. If a refrigerant leakage detection signal has been received (Yes in step S402), the process proceeds to step S403. If a refrigerant leakage detection signal has not been received (No in step S402), the process proceeds to step S404.

[0068] In step S403, the indoor control unit 61 causes the notification means 24 to notify the user of a refrigerant leak. At this time, refrigerant is leaking from both the outdoor unit 10 and the indoor unit 20, making it difficult to ensure safety by controlling the air conditioner 1. Therefore, it is preferable to issue an alarm that is louder than the notifications in steps S404 and S408, which will be described later, so that the user can immediately notice the notification of a refrigerant leak. Furthermore, specific instructions to ensure the user's safety, such as opening a window or not using open flames, may also be issued.

[0069] In step S404, the indoor control unit 61 causes the notification means 24 to notify the user of the refrigerant leak. The notification means 24 notifies the user of the refrigerant leak by voice or screen display, etc. Next, the process proceeds to step S405.

[0070] In step S405, the indoor control unit 61 controls the indoor power supply circuit 62 to cut off the power supply to the outdoor unit 10. As a result, the refrigerant circuit of the air conditioner 1 stops operating.

[0071] In step S406, the indoor control unit 61 determines whether or not a refrigerant leakage detection signal has been received from the indoor refrigerant detection sensor 30c. If a refrigerant leakage detection signal has been received (Yes in step S406), the process proceeds to step S407. If a refrigerant leakage detection signal has not been received (No in step S406), the process returns to step S401.

[0072] In step S407, the indoor control unit 61 transmits a refrigerant recovery notification to the outdoor communication unit 53 via the indoor communication unit 63. Upon receiving the refrigerant recovery notification via the outdoor communication unit 53, the outdoor control unit 51 causes the compressor control unit 54 to perform pump-down operation of the compressor 11. Pump-down operation of the compressor 11 refers to operation in which the compressor is driven while the refrigerant circuit is blocked at the outlet of the outdoor heat exchanger 13 in the refrigerant flow direction. Pump-down operation forcibly collects refrigerant in the refrigerant circuit in the outdoor heat exchanger 13. In step S407, refrigerant is leaking only inside the indoor unit 20. Therefore, collecting refrigerant in the refrigerant circuit in the outdoor heat exchanger 13 of the outdoor unit 10 can prevent refrigerant from leaking from the indoor unit 20. In step S407, the indoor control unit 61 may also transmit a notification to the outdoor communication unit 53 via the indoor communication unit 63 indicating that refrigerant is not leaking from the indoor unit 20. Next, the process proceeds to step S408.

[0073] In step S408, the indoor control unit 61 causes the notification means 24 to notify the user of the refrigerant leakage. The notification means 24 notifies the user of the refrigerant leakage by voice or on-screen display.

[0074] As described above, a refrigerant leak is detected by the refrigerant detection sensor 30a, which detects a refrigerant leak before it flows into the outdoor electrical equipment box 16, and the indoor refrigerant detection sensor 30c, which detects a refrigerant leak inside the indoor unit 20, and processing is changed depending on the location of the refrigerant leak. If a refrigerant leak occurs near the outdoor electrical equipment box 16, the operation of electronic components having moving parts is stopped, as in the first embodiment. If a refrigerant leak occurs near the outdoor electrical equipment box 16 and inside the indoor unit 20, it is difficult to ensure safety in the air conditioner 1, so the user is notified of the refrigerant leak and is urged to take measures. If a refrigerant leak occurs near the outdoor electrical equipment box 16 but not inside the indoor unit 20, the power supply to the outdoor unit 10 is cut off to prevent the leaked refrigerant in the outdoor unit 10 from igniting. If the refrigerant is not leaking near the outdoor electrical equipment box 16 and is leaking inside the indoor unit 20, the compressor 11 of the outdoor unit 10 is pumped down to collect the refrigerant in the outdoor unit 10, thereby suppressing the refrigerant leakage from the indoor unit 20.

[0075] As described above, the outdoor unit 10 of the air conditioner 1 of the present disclosure comprises a housing 10a, a compressor 11 that is disposed within the housing 10a and compresses a flammable refrigerant, an outdoor heat exchanger 13 that is disposed within the housing 10a and connected to the compressor 11 via a refrigerant pipe 40 through which the flammable refrigerant flows and that exchanges heat between the flammable refrigerant and air, an outdoor electrical equipment box 16 that is disposed within the housing 10a above the compressor 11, a refrigerant detection sensor 30a that is installed outside the outdoor electrical equipment box 16 and detects leakage of the flammable refrigerant, and a refrigerant detection sensor 30a that is disposed within the outdoor electrical equipment box 16 and is composed of a plurality of electronic components and that detects leakage of the flammable refrigerant. the indoor unit (20) having an indoor control device (60) that receives a refrigerant leakage notification from the outdoor control device (50) indicating that a flammable refrigerant leak has been detected in the outdoor unit (10); and notification means (24) that is communicatively connected to the indoor control device (60) and that notifies the user, wherein the indoor control device (60) causes the notification means (24) to notify the user of a refrigerant leak when the indoor control device (60) receives the refrigerant leakage notification, and the indoor unit (20) further has an indoor refrigerant detection sensor (30c) inside that detects a flammable refrigerant leak.

[0076] With this configuration, refrigerant leakage between the outdoor electrical equipment box 16 of the outdoor unit 10 and the inside of the indoor unit 20 can be detected.

[0077] Furthermore, when the indoor control device 60 receives a refrigerant leakage notification from the outdoor control device 50, it cuts off the power supply to the outdoor unit 10. As a result, when a refrigerant leaks in the outdoor unit 10, the operation of the outdoor unit 10 is stopped, thereby preventing the refrigerant from catching fire.

[0078] Furthermore, when the indoor control device 60 receives a refrigerant leak notification from the outdoor control device 50 and the indoor refrigerant detection sensor 30c detects a flammable refrigerant leak, it causes the notification means 24 to notify the user of the flammable refrigerant leak. This makes it possible to notify the user when a refrigerant leak has occurred between the indoor unit 20 and the outdoor unit 10 and it is difficult to ensure safety using the air conditioner 1.

[0079] Furthermore, if the refrigerant detection sensor 30a does not detect a flammable refrigerant leak and the indoor refrigerant detection sensor 30c detects a refrigerant leak, the outdoor control device 50 causes the compressor 11 to perform pump-down operation to recover the flammable refrigerant to the outdoor unit 10. As a result, if refrigerant is leaking in the indoor unit 20 but not in the outdoor unit 10, the safety of the indoor unit 20 can be ensured by recovering the refrigerant in the outdoor unit 10.

[0080] The configurations shown in the above embodiments are examples of the content of the present invention, and may be combined with other known technologies, and some of the configurations may be omitted or modified within the scope of the gist of the present invention.

[0081] According to the present disclosure, it is possible to provide an outdoor unit for an air conditioner that can prevent refrigerant from catching fire when a refrigerant leak is detected.

[0082] REFRIGERATED TERMS AND CONDITIONS 1 Air conditioner, 10 Outdoor unit, 11 Compressor, 12 Four-way valve, 13 Outdoor heat exchanger, 14 Expansion valve, 15 Outdoor fan, 16 Outdoor electrical equipment box, 17 Separator, 18 Machine room, 19 Blower room, 20 Indoor unit, 21 Indoor heat exchanger, 22 Indoor fan, 23 Indoor electrical equipment box, 24 Notification means, 30a Refrigerant detection sensor, 30b Second refrigerant detection sensor, 30c Indoor refrigerant detection sensor, 40 Refrigerant piping, 40b Liquid refrigerant piping, 40a Gas refrigerant piping, 50 Outdoor control device, 51 Outdoor control unit, 52 Outdoor power supply circuit, 53 Outdoor communication unit, 54 Compressor control unit, 55 Outdoor fan control unit, 60 Indoor control device, 61 Indoor control unit, 62 Indoor power supply circuit, 63 Indoor communication unit, 64 Indoor fan control unit, 70 System power supply.

Claims

1. A housing having an interior divided into a machine room and a ventilation room, A compressor for compressing a flammable refrigerant is located inside the aforementioned machine room. An outdoor heat exchanger is located in the aforementioned ventilation chamber, connected to the compressor via refrigerant piping through which the flammable refrigerant flows, and performs heat exchange between the flammable refrigerant and air. An outdoor electrical equipment box is located above the compressor in the machine room, A refrigerant detection sensor is installed in the machine room above the compressor and below the outdoor electrical equipment box to detect leakage of the flammable refrigerant, An outdoor control device is located inside the outdoor electrical equipment box and is composed of multiple electronic components. When the refrigerant detection sensor detects a leak of the flammable refrigerant, the control device stops the operation of the electronic components that have movable parts. An outdoor unit for an air conditioner equipped with [a specific feature / feature].

2. The outdoor unit of the air conditioner according to claim 1, characterized in that the refrigerant detection sensor is arranged on the outer surface of the outdoor electrical equipment box.

3. An outdoor unit according to claim 1 or 2, An indoor unit having an indoor control unit that receives a refrigerant leak notification from the outdoor control unit indicating that it has detected a leak of the flammable refrigerant in the outdoor unit, It is connected to the aforementioned indoor control device in a communicative manner and includes a notification means for notifying the user, The indoor control device is an air conditioner that, upon receiving the refrigerant leak notification, causes the notification means to notify that a refrigerant has leaked.

4. The outdoor unit of an air conditioner according to claim 1 or 2, further comprising a second refrigerant detection sensor for detecting leakage of the flammable refrigerant, located below the refrigerant detection sensor within the housing.

5. Housing and A compressor for compressing a flammable refrigerant is placed inside the aforementioned enclosure, An outdoor heat exchanger is located within the aforementioned enclosure, connected to the compressor via refrigerant piping through which the flammable refrigerant flows, and performs heat exchange between the flammable refrigerant and air. An outdoor electrical equipment box is located above the compressor within the aforementioned enclosure, A refrigerant detection sensor is installed on the outside of the aforementioned outdoor electrical equipment box to detect leakage of the flammable refrigerant, An outdoor control device is located inside the outdoor electrical equipment box and is composed of multiple electronic components. When the refrigerant detection sensor detects a leak of the flammable refrigerant, the control device stops the operation of the electronic components that have movable parts. Within the housing, below the refrigerant detection sensor, is a second refrigerant detection sensor for detecting leakage of the flammable refrigerant, An outdoor fan is placed inside the aforementioned enclosure and generates airflow that passes through the outdoor heat exchanger, Equipped with, The outdoor unit of an air conditioner is characterized in that the outdoor control device drives the outdoor fan when the refrigerant detection sensor does not detect a leak of the flammable refrigerant, and the second refrigerant detection sensor detects a leak of the flammable refrigerant.

6. The air conditioner according to claim 3, wherein the indoor unit further comprises an indoor refrigerant detection sensor for detecting leakage of the flammable refrigerant.

7. The air conditioner according to claim 6, characterized in that when the indoor control device receives a refrigerant leak notification from the outdoor control device, it shuts off the power supply to the outdoor unit.

8. The air conditioner according to claim 6, wherein the indoor control device receives the refrigerant leak notification from the outdoor control device, and when the indoor refrigerant detection sensor detects a leak of the flammable refrigerant, it causes the notification means to notify the leak of the flammable refrigerant.

9. The air conditioner according to claim 6, characterized in that, if the outdoor control device does not detect a leak of the flammable refrigerant by the refrigerant detection sensor and the indoor refrigerant detection sensor detects a leak of the flammable refrigerant, the compressor is operated in a pump-down operation to recover the flammable refrigerant to the outdoor unit.