Air-conditioning device

Abstract

This air-conditioning device compares a first operation valve provided between a compressor and an indoor heat exchanger on a gas pipe, a second operation valve provided between the expansion valve and the indoor heat exchanger on a liquid pipe, a first temperature measurement unit for measuring the temperature of the indoor heat exchanger, a second temperature measurement unit for measuring the temperature of an outdoor heat exchanger, a third temperature measurement unit for measuring the indoor temperature, a fourth temperature measurement unit for measuring the outdoor temperature, and a control device. The control device has an operation determination unit, a first comparison unit for comparing the outdoor temperature with the temperature of the outdoor heat exchanger in the case of a cooling operation, and a first determination unit for determining the state of each device when the temperature of the outdoor heat exchanger is lower than the outdoor temperature.

Description

Technical Field

[0001] The present disclosure relates to an air conditioner.

[0002] Priority is claimed on Japanese Patent Application No. 2023-166722, filed September 28, 2023, the content of which is incorporated herein by reference.Background Art

[0003] In an air conditioner using a refrigeration cycle, an abnormality such as a low-gas state (insufficient refrigerant amount), closing of an operation valve, and switching failure of a four-way valve may occur. It is known that, in such a state, the operation is continued, which causes a failure of the compressor.

[0004] As a technique for determining a type of an abnormality of a refrigeration cycle, a technique described in PTL 1 below is known. In the device according to PTL 1, it is said that a temperature of any one of an indoor heat exchanger and an outdoor heat exchanger can be acquired as an indicator, and various abnormal states can be determined based on the indicator.Citation ListPatent Literature

[0005] [PTL 1] Japanese Unexamined Patent Application Publication No. 2003-090582Summary of InventionTechnical Problem

[0006] However, when the temperature of only any one of the indoor heat exchanger and the outdoor heat exchanger is used as the indicator as described above, there is a concern that the accuracy of the determination of the abnormal state may be impaired. For example, a disadvantage remains that the closing of the operation valve of the gas pipe (pipe through which the gas-phase refrigerant flows) and the closing of the operation valve of the liquid pipe (pipe through which the liquid-phase refrigerant flows) cannot be determined.

[0007] The present disclosure provides an air conditioner capable of more finely determining a type of an abnormal state.Solution to Problem

[0008] An air conditioner according to the present disclosure includes an indoor heat exchanger, an outdoor heat exchanger, a gas pipe that connects the indoor heat exchanger and the outdoor heat exchanger and through which a gas-phase refrigerant flows, a compressor that is disposed on the gas pipe, a liquid pipe that connects the indoor heat exchanger and the outdoor heat exchanger, through which a liquid-phase or gas-liquid two-phase refrigerant flows, and that forms a circulation circuit together with the gas pipe, an expansion valve that is provided on the liquid pipe, and a four-way valve that switches a flow direction of the refrigerant between a cooling operation and a heating operation, in which the air conditioner further includes a first operation valve that is provided between the compressor and the indoor heat exchanger on the gas pipe, a second operation valve that is provided between the expansion valve and the indoor heat exchanger on the liquid pipe, a first temperature measurement unit that measures a temperature of the indoor heat exchanger, a second temperature measurement unit that measures a temperature of the outdoor heat exchanger, a third temperature measurement unit that measures an indoor temperature, a fourth temperature measurement unit that measures an outdoor temperature, and a control device, the control device includes an operation determination unit that determines whether the air conditioner is in the cooling operation or the heating operation, a first comparison unit that compares the temperature of the outdoor heat exchanger with the outdoor temperature in a case of the cooling operation, and a first determination unit that determines a state of each device when the temperature of the outdoor heat exchanger is lower than the outdoor temperature, and the first determination unit determines that a switching failure of the four-way valve has occurred when the temperature of the indoor heat exchanger is equal to or higher than a predetermined first threshold value, and determines that the first operation valve and the second operation valve are in a closed state when the temperature of the indoor heat exchanger is lower than the first threshold value.

[0009] An air conditioner according to the present disclosure includes an indoor heat exchanger, an outdoor heat exchanger, a gas pipe that connects the indoor heat exchanger and the outdoor heat exchanger and through which a gas-phase refrigerant flows, a compressor that is disposed on the gas pipe, a liquid pipe that connects the indoor heat exchanger and the outdoor heat exchanger, through which a liquid-phase refrigerant flows, and that forms a circulation circuit together with the gas pipe, an expansion valve that is provided on the liquid pipe, and a four-way valve that switches a flow direction of the refrigerant between a cooling operation and a heating operation, in which the air conditioner further includes a first operation valve that is provided between the compressor and the indoor heat exchanger on the gas pipe, a second operation valve that is provided between the expansion valve and the indoor heat exchanger on the liquid pipe, a first temperature measurement unit that measures a temperature of the indoor heat exchanger, a second temperature measurement unit that measures a temperature of the outdoor heat exchanger, a third temperature measurement unit that measures an indoor temperature, a fourth temperature measurement unit that measures an outdoor temperature, and a control device, the control device includes an operation determination unit that determines whether the air conditioner is in the cooling operation or the heating operation, a first comparison unit that compares the temperature of the outdoor heat exchanger with the outdoor temperature in a case of the heating operation, and a first determination unit that determines a state of each device when the temperature of the outdoor heat exchanger is higher than the outdoor temperature, and the first determination unit determines that a switching failure of the four-way valve has occurred when the temperature of the indoor heat exchanger is lower than a predetermined first threshold value.Advantageous Effects of Invention

[0010] According to the present disclosure, it is possible to provide an air conditioner capable of more finely determining a type of an abnormal state.Brief Description of Drawings

[0011] FIG. 1 is a circuit diagram of an air conditioner according to an embodiment of the present disclosure, and is a diagram showing a state during a cooling operation. FIG. 2 is a circuit diagram of the air conditioner according to the embodiment of the present disclosure, and a diagram showing a state during a heating operation. FIG. 3 is a table showing a relationship between various indicators and an abnormal state in the air conditioner according to the embodiment of the present disclosure. FIG. 4 is a functional block diagram of a control device according to the embodiment of the present disclosure. FIG. 5 is a control flow of the control device according to the embodiment of the present disclosure during the cooling operation. FIG. 6 is another control flow of the control device according to the embodiment of the present disclosure during the cooling operation and the heating operation. FIG. 7 is a control flow of the control device according to the embodiment of the present disclosure during the heating operation. FIG. 8 is a hardware configuration diagram of a control device according to the embodiment of the present disclosure. Description of Embodiments(Configuration of Air Conditioner 1)

[0012] Hereinafter, an air conditioner 1 according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 8. As shown in FIG. 1, the air conditioner 1 includes a refrigeration cycle circuit 10, a first operation valve 20, a second operation valve 30, a first temperature measurement unit 41, a second temperature measurement unit 42, a third temperature measurement unit 43, a fourth temperature measurement unit 44, and a control device 50.(Refrigeration Cycle Circuit 10)

[0013] The refrigeration cycle circuit 10 includes an indoor heat exchanger 11, an outdoor heat exchanger 12, a gas pipe 13, a compressor 14, a liquid pipe 15, an expansion valve 16, and a four-way valve (not shown).

[0014] The indoor heat exchanger 11 performs heat exchange between air in a room and a refrigerant. The indoor heat exchanger 11 is, for example, a heat exchanger of a fin-and-tube type or a plate type, and a refrigerant flows inside. Although not shown, it is desirable that a fan that blows air into the room be provided in the indoor heat exchanger 11.

[0015] The outdoor heat exchanger 12 performs heat exchange between air outside the room and a refrigerant. The outdoor heat exchanger 12 is, for example, a heat exchanger of a fin-and-tube type or a plate type, and a refrigerant flows inside, as in the indoor heat exchanger 11. Although not shown, it is desirable that a fan that blows air into the outside of the room be provided in the outdoor heat exchanger 12.(Gas Pipe 13 and Compressor 14)

[0016] The gas pipe 13 is a pipe that connects the indoor heat exchanger 11 and the outdoor heat exchanger 12, and a gas-phase refrigerant flows inside. The compressor 14 is provided on the gas pipe 13. The compressor 14 is, for example, a scroll type or a rotary type rotary machine, and compresses a gas-phase refrigerant flowing in from an inlet side to raise the pressure of the refrigerant to a predetermined pressure, and then discharges the refrigerant to the gas pipe 13.(Liquid Pipe 15 and Expansion Valve 16)

[0017] The liquid pipe 15 is a pipe that connects the indoor heat exchanger 11 and the outdoor heat exchanger 12, and a liquid-phase or gas-liquid two-phase refrigerant flows inside. The liquid pipe 15 forms a circulation circuit together with the gas pipe 13. That is, both end portions of the liquid pipe 15 are connected to end portions different from the end portions of the indoor heat exchanger 11 and the outdoor heat exchanger 12 to which the gas pipe 13 is connected. The expansion valve 16 is provided on the liquid pipe 15. The expansion valve 16 is, for example, an electromagnetic expansion valve 16, and has a function of expanding a refrigerant flowing through the liquid pipe 15 to reduce the pressure.

[0018] Although not shown, the four-way valve is a valve that switches a flow direction of the refrigerant in the gas pipe 13 and the liquid pipe 15 between the cooling operation and the heating operation. During the cooling operation, as shown in FIG. 1, the refrigerant flows in the order of the compressor 14, the outdoor heat exchanger 12, the expansion valve 16, and the indoor heat exchanger 11. On the other hand, during the heating operation, as shown in FIG. 2, the refrigerant flows in the order of the compressor 14, the indoor heat exchanger 11, the expansion valve 16, and the outdoor heat exchanger 12.(Operation of Refrigeration Cycle Circuit 10)

[0019] Subsequently, the operation of the refrigeration cycle circuit 10 during the cooling operation will be described. During the cooling operation, the high-temperature and high-pressure gas-phase refrigerant discharged from the compressor 14 flows into the outdoor heat exchanger 12. In the outdoor heat exchanger 12, the refrigerant exchanges heat with the air outside the room to become a high-temperature and high-pressure liquid-phase refrigerant. Next, the refrigerant passes through the expansion valve 16 to be depressurized, and becomes a low-temperature and low-pressure liquid-phase or gas-liquid two-phase refrigerant. Further, the refrigerant flows into the indoor heat exchanger and exchanges heat with the air in the room. That is, the low-temperature refrigerant exchanges heat with the high-temperature air in the room, and the air temperature in the room is lowered. On the other hand, the temperature of the refrigerant is raised, and the refrigerant becomes a low-temperature and low-pressure gas-phase refrigerant. The refrigerant flows again into the compressor 14, and the above-described cycle continuously occurs.

[0020] On the other hand, during the heating operation, the high-temperature and high-pressure gas-phase refrigerant discharged from the compressor 14 flows into the indoor heat exchanger 11. In the indoor heat exchanger 11, the refrigerant exchanges heat with the air in the room to become a high-temperature and high-pressure liquid-phase refrigerant. Next, the refrigerant passes through the expansion valve 16 to be depressurized, and becomes a low-temperature and low-pressure gas-liquid two-phase refrigerant. Further, the refrigerant flows into the outdoor heat exchanger and exchanges heat with the air outside the room. That is, the low-temperature refrigerant exchanges heat with the air outside the room, and a low-temperature and low-pressure gas-phase refrigerant is generated. The refrigerant flows again into the compressor 14, and the above-described cycle continuously occurs.(First Operation Valve 20 and Second Operation Valve 30)

[0021] The first operation valve 20 is a valve that switches a flow state of the refrigerant in the gas pipe 13. The second operation valve 30 is a valve that switches a flow state of the refrigerant in the liquid pipe 15. As these valves, an electromagnetic on / off valve is suitably used.(First Temperature Measurement Unit 41 to Fourth Temperature Measurement Unit 44)

[0022] The first temperature measurement unit 41 is a temperature sensor that measures a temperature of the indoor heat exchanger 11. The second temperature measurement unit 42 is a temperature sensor that measures a temperature of the outdoor heat exchanger 12. These sensors directly measure a temperature of a pipe, a fin, or the like in the heat exchanger, instead of a temperature of the refrigerant in the heat exchanger. The third temperature measurement unit 43 measures the indoor temperature, and the fourth temperature measurement unit 44 measures the outdoor temperature. The first temperature measurement unit 41 to the fourth temperature measurement unit 44 are electrically connected to the control device 50 described below, and transmit each measurement result to the control device 50 as an electric signal.(Control Device 50)

[0023] The control device 50 detects and determines an abnormal state of various devices based on the results measured by the first temperature measurement unit 41 to the fourth temperature measurement unit 44. As shown in FIG. 4, the control device 50 includes an operation determination unit 51, a first comparison unit 52, a first determination unit 53, a second comparison unit 54, a second determination unit 55, a third determination unit 56, a fourth determination unit 57, and a storage unit 58. Hereinafter, the operation of each functional block will be described with reference to flowcharts shown in FIGS. 5 to 7.(Operation of Each Functional Block during Cooling Operation)

[0024] The operation determination unit 51 determines whether the air conditioner 1 is in a cooling operation state or a heating operation state (step S11). First, the operation of each functional block during the cooling operation will be described. The first comparison unit 52 compares the temperature of the outdoor heat exchanger 12 and the outdoor temperature in a case of the cooling operation (step S12). The first determination unit 53 determines the state of each device when it is determined that the temperature of the outdoor heat exchanger 12 is lower than the outdoor temperature (step S13). Specifically, the first determination unit 53 determines that a switching failure of the four-way valve has occurred when the temperature of the indoor heat exchanger 11 is equal to or higher than a predetermined first threshold value, and determines that the first operation valve 20 and the second operation valve 30 are in a closed state when the temperature of the indoor heat exchanger 11 is lower than the first threshold value.

[0025] That is, the type of the abnormal state is determined based on the relationship between the measured temperature of each unit and the state of various devices shown in FIG. 3. Each state of [1] to [5] in FIG. 3 corresponds to each number of [1] to [5] in FIGS. 5 to 7.

[0026] The second comparison unit 54 compares the temperature of the indoor heat exchanger 11 and the indoor temperature when it is determined by the first comparison unit 52 that the temperature of the outdoor heat exchanger 12 is higher than the outdoor temperature (step S14). The second determination unit 55 determines the state of each device by comparing the temperature of the indoor heat exchanger 11 and a predetermined second threshold value when it is determined in step S14 that the temperature of the indoor heat exchanger 11 is higher than the indoor temperature (step S15). Specifically, the second determination unit 55 determines that the first operation valve 20 is in a closed state when the temperature of the indoor heat exchanger 11 is higher than the second threshold value, and determines that the first operation valve 20 and the second operation valve 30 are in a closed state when the temperature of the indoor heat exchanger 11 is lower than the second threshold value.

[0027] On the other hand, when it is determined by the first comparison unit 52 that the temperature of the outdoor heat exchanger 12 is lower than the outdoor temperature, the abnormal state is determined by the third determination unit 56 (step S16). Specifically, the third determination unit 56 determines the state of each device by comparing the temperature of the indoor heat exchanger 11 with a predetermined third threshold value and a fourth threshold value that is a value higher than the third threshold value. More specifically, the third determination unit 56 determines that the second operation valve 30 is in the closed state or in the normal operation state when the temperature of the indoor heat exchanger 11 is lower than the third threshold value. When the temperature of the indoor heat exchanger 11 is higher than the third threshold value and lower than the fourth threshold value, it is determined that the filling amount of the refrigerant is reduced. Further, when the temperature of the indoor heat exchanger 11 is higher than the fourth threshold value, it is determined that the first operation valve 20 and the second operation valve 30 are in the closed state.

[0028] When it is determined by the third determination unit 56 that the temperature of the indoor heat exchanger 11 is lower than the third threshold value, further determination is performed by the fourth determination unit 57. As shown in FIG. 6, the fourth determination unit 57 operates for a predetermined time in a state where the rotation speed of the compressor 14 is higher than a predetermined rotation speed threshold value (step S21). Thereafter, when the temperature of the indoor heat exchanger 11 is higher than a predetermined fifth threshold value, it is determined that the second operation valve 30 is in the closed state (step S22). That is, it is determined whether the second operation valve 30 is in the normal operation state or in the closed state.(Operation of Each Functional Block during Heating Operation)

[0029] On the other hand, during the heating operation, each functional block operates as shown in FIG. 7. That is, even when it is determined in step S31 that the heating operation is performed, the first comparison unit 52 compares the temperature of the outdoor heat exchanger 12 and the outdoor temperature (step S32). The first determination unit 53 determines the state of each device when it is determined that the temperature of the outdoor heat exchanger 12 is higher than the outdoor temperature. Specifically, the first determination unit 53 determines that the switching failure of the four-way valve has occurred when the temperature of the indoor heat exchanger 11 is lower than the predetermined first threshold value (step S33).

[0030] On the other hand, when it is determined by the first determination unit 53 that the temperature of the outdoor heat exchanger 12 is lower than the outdoor temperature, the second comparison unit 54 compares the temperature of the indoor heat exchanger 11 and the indoor temperature (step S34). When it is determined in step S34 that the temperature of the indoor heat exchanger 11 is lower than the indoor temperature, the second determination unit 55 determines the state of each device by comparing the temperature of the indoor heat exchanger 11 and the predetermined second threshold value. Specifically, the second determination unit 55 determines that the first operation valve 20 and the second operation valve 30 are in the closed state when the temperature of the indoor heat exchanger 11 is higher than the second threshold value, and determines that the first operation valve 20 is in the closed state when the temperature of the indoor heat exchanger 11 is equal to or lower than the second threshold value (step S35).

[0031] Further, when it is determined by the second comparison unit 54 that the temperature of the indoor heat exchanger 11 is higher than the indoor temperature, the third determination unit 56 determines the state of each device. Specifically, the third determination unit 56 compares the temperature of the indoor heat exchanger 11 with the predetermined third threshold value and the fourth threshold value that is a value higher than the third threshold value. The third determination unit 56 determines that the first operation valve 20 and the second operation valve 30 are in the closed state when the temperature of the indoor heat exchanger 11 is lower than the third threshold value. When the temperature of the indoor heat exchanger 11 is higher than the third threshold value and lower than the fourth threshold value, it is determined that the filling amount of the refrigerant is reduced. When the temperature of the indoor heat exchanger 11 is higher than the fourth threshold value, it is determined that the second operation valve 30 is in the closed state or in the normal operation state (step S36).

[0032] When it is determined by the third determination unit 56 that the temperature of the indoor heat exchanger 11 is higher than the third threshold value, further determination is performed by the fourth determination unit 57. As shown in FIG. 6, when it is determined that the temperature of the indoor heat exchanger 11 is higher than the fourth threshold value, the fourth determination unit 57 operates for a predetermined time in a state where the rotation speed of the compressor 14 is higher than the predetermined rotation speed threshold value (step S21). Thereafter, when the temperature of the outdoor heat exchanger 12 is lower than a predetermined sixth threshold value, it is determined that the second operation valve 30 is in the closed state (step S22).(Operations and Effects)

[0033] Here, in the device in the related art, it is common to acquire the temperature of any one of the indoor heat exchanger 11 and the outdoor heat exchanger 12 as an indicator, and to determine various abnormal states based on the indicator. However, in this case, there is a concern that the accuracy of the determination of the abnormal state may be impaired. For example, a disadvantage remains that the closing of the operation valve of the gas pipe 13 (pipe through which the gas-phase refrigerant flows) and the closing of the operation valve of the liquid pipe 15 (pipe through which the liquid-phase refrigerant flows) cannot be determined. Therefore, in the present embodiment, each of the configurations described above is adopted.

[0034] According to the above-described configuration, the first determination unit 53 can determine the switching failure of the four-way valve and the closing of the first operation valve 20 and the second operation valve 30 based on the temperature of the indoor heat exchanger 11, the temperature of the outdoor heat exchanger 12, the indoor temperature, and the outdoor temperature. That is, when the switching failure of the four-way valve occurs in the cooling operation state, the flow direction of the refrigerant is opposite to a predetermined direction, so that the temperature of the indoor heat exchanger 11 is raised and the temperature of the outdoor heat exchanger 12 is lowered. On the other hand, when the switching of the four-way valve is normal and the closing of the first operation valve 20 and the second operation valve 30 occurs, the temperatures of the indoor heat exchanger 11 and the outdoor heat exchanger 12 do not change. Based on the indicators of these temperatures, it is possible to more finely determine the abnormal state. Therefore, when the abnormality occurs, an appropriate measure for recovery can be taken immediately. As a result, the air conditioner 1 can be operated more stably over a long period.

[0035] According to the above-described configuration, the second determination unit 55 can determine whether the first operation valve 20 is in the closed state or the first operation valve 20 and the second operation valve 30 are in the closed state based on the temperature of the indoor heat exchanger 11 and the indoor temperature. That is, when the first operation valve 20 is in the closed state in the cooling operation state, the refrigerant present in the section between the first operation valve 20 and the inlet of the compressor 14 flows into the indoor heat exchanger 11 and the outdoor heat exchanger 12, but the amount is small, so that the pressure increase width is small. Therefore, the change amount of the temperature of the indoor heat exchanger 11 and the outdoor heat exchanger 12 is small. On the other hand, when the first operation valve 20 and the second operation valve 30 are in the closed state, the state where the indoor heat exchanger 11 and the outdoor heat exchanger 12 are blocked is established, so that the change amount of the temperature of the indoor heat exchanger 11 is extremely small. In addition, the refrigerant present in the section between the first operation valve 20 and the inlet of the compressor 14 flows into the indoor heat exchanger 11 and the outdoor heat exchanger 12, but the amount is small, so that the pressure increase width of the outdoor heat exchanger 12 is small. Therefore, the change amount of the temperature of the outdoor heat exchanger 12 is small. Based on the indicators of these temperatures, it is possible to more finely determine the abnormal state. Therefore, when the abnormality occurs, an appropriate measure for recovery can be taken immediately. As a result, the air conditioner 1 can be operated more stably over a long period.

[0036] According to the above-described configuration, the third determination unit 56 can determine whether the second operation valve 30 is in the closed state or in the normal operation state, whether the filling amount of the refrigerant is reduced, and whether the first operation valve 20 and the second operation valve 30 are in the closed state based on the temperature of the indoor heat exchanger 11 and the indoor temperature. That is, when the filling amount of the refrigerant is reduced in the cooling operation state, the flow direction of the refrigerant is the same as in the normal operation, so that the temperature change of the indoor heat exchanger 11 and the outdoor heat exchanger 12 is small. In addition, when the second operation valve 30 is in the closed state, the pressure of the indoor heat exchanger 11 is lowered, so that the temperature of the indoor heat exchanger 11 is also lowered. On the other hand, the pressure of the outdoor heat exchanger 12 is raised, so that the temperature of the outdoor heat exchanger 12 is raised. Based on the indicators of these temperatures, it is possible to more finely determine the abnormal state. Therefore, when the abnormality occurs, an appropriate measure for recovery can be taken immediately. As a result, the air conditioner 1 can be operated more stably over a long period.

[0037] According to the above-described configuration, when it is determined by the third determination unit 56 that the temperature of the indoor heat exchanger 11 is lower than the third threshold value, the compressor 14 can be operated at a predetermined rotation speed for a certain time, and then the fourth determination unit 57 can determine whether the second operation valve 30 is in the closed state or in the normal operation state based on the comparison with a further threshold value. That is, when the second operation valve 30 is in the closed state in the cooling operation state, the pressure of the indoor heat exchanger 11 is lowered, so that the temperature of the indoor heat exchanger 11 is also lowered. On the other hand, the pressure of the outdoor heat exchanger 12 is raised, so that the temperature of the outdoor heat exchanger 12 is raised. Based on the indicators of these temperatures, it is possible to more finely determine the abnormal state. Therefore, when the abnormality occurs, an appropriate measure for recovery can be taken immediately. As a result, the air conditioner 1 can be operated more stably over a long period.

[0038] According to the above-described configuration, the first determination unit 53 can determine the switching failure of the four-way valve based on the temperature of the indoor heat exchanger 11, the temperature of the outdoor heat exchanger 12, the indoor temperature, and the outdoor temperature. That is, when the switching failure of the four-way valve occurs in the heating operation state, the flow direction of the refrigerant is opposite to a predetermined direction, so that the temperature of the indoor heat exchanger 11 is lowered and the temperature of the outdoor heat exchanger 12 is raised. Based on the indicators of these temperatures, it is possible to more finely determine the abnormal state. Therefore, when the abnormality occurs, an appropriate measure for recovery can be taken immediately. As a result, the air conditioner 1 can be operated more stably over a long period.

[0039] According to the above-described configuration, the second determination unit 55 can determine whether the first operation valve 20 is in the closed state or the first operation valve 20 and the second operation valve 30 are in the closed state based on the temperature of the indoor heat exchanger 11 and the indoor temperature. That is, when the first operation valve 20 is in the closed state in the heating operation state, all the refrigerant flows into the section between the first operation valve 20 and the inlet of the compressor 14, so that the pressure of the indoor heat exchanger 11 and the outdoor heat exchanger 12 is lowered. Therefore, the temperature of the indoor heat exchanger 11 and the outdoor heat exchanger 12 is also lowered. On the other hand, when the first operation valve 20 and the second operation valve 30 are in the closed state, the state where the indoor heat exchanger 11 and the outdoor heat exchanger 12 are blocked is established, so that the change amount of the temperature of the outdoor heat exchanger 12 is extremely small. In addition, since all the refrigerant flows into the section between the first operation valve 20 and the inlet of the compressor 14, the pressure of the outdoor heat exchanger 12 is lowered. Therefore, the temperature of the outdoor heat exchanger 12 is also lowered. Based on the indicators of these temperatures, it is possible to more finely determine the abnormal state. Therefore, when the abnormality occurs, an appropriate measure for recovery can be taken immediately. As a result, the air conditioner 1 can be operated more stably over a long period.

[0040] According to the above-described configuration, the third determination unit 56 can determine whether the second operation valve 30 is in the closed state or in the normal operation state, whether the filling amount of the refrigerant is reduced, and whether the first operation valve 20 and the second operation valve 30 are in the closed state based on the temperature of the indoor heat exchanger 11 and the indoor temperature. That is, when the filling amount of the refrigerant is reduced in the heating operation state, the flow direction of the refrigerant is the same as in the normal operation, so that the temperature change of the indoor heat exchanger 11 and the outdoor heat exchanger 12 is small. In addition, when the second operation valve 30 is in the closed state, the pressure of the indoor heat exchanger 11 is raised, so that the temperature of the indoor heat exchanger 11 is also raised. On the other hand, the pressure of the outdoor heat exchanger 12 is lowered, so that the temperature of the outdoor heat exchanger 12 is lowered. Based on the indicators of these temperatures, it is possible to more finely determine the abnormal state. Therefore, when the abnormality occurs, an appropriate measure for recovery can be taken immediately. As a result, the air conditioner 1 can be operated more stably over a long period.

[0041] According to the above-described configuration, when it is determined by the third determination unit 56 that the temperature of the indoor heat exchanger 11 is higher than the fourth threshold value, the compressor 14 can be operated at a predetermined rotation speed for a certain time, and then the fourth determination unit 57 can determine whether the second operation valve 30 is in the closed state or in the normal operation state based on the comparison with a further threshold value. That is, when the second operation valve 30 is in the closed state in the heating operation state, the pressure of the indoor heat exchanger 11 is raised, so that the temperature of the indoor heat exchanger 11 is also raised. On the other hand, the pressure of the outdoor heat exchanger 12 is lowered, so that the temperature of the outdoor heat exchanger 12 is also lowered. Based on the indicators of these temperatures, it is possible to more finely determine the abnormal state. Therefore, when the abnormality occurs, an appropriate measure for recovery can be taken immediately. As a result, the air conditioner 1 can be operated more stably over a long period.(Other Embodiments)

[0042] The embodiments of the present disclosure have been described in detail with reference to the drawings hereinbefore. However, the specific configuration is not limited to the embodiments, and includes design changes and the like within a scope not departing from the gist of the present disclosure. For example, the configuration of the refrigeration cycle circuit 10 is an example, and a configuration including other auxiliaries such as a receiver (not shown) can be adopted. That is, the above-described configurations can be applied to any device using a refrigeration cycle. In other words, regardless of the form of the refrigeration cycle device or the type of the auxiliaries, the abnormal state can be accurately determined by the above-described configuration while maintaining high versatility.

[0043] In a processing flow of the control device 50 of the embodiments of the present disclosure, the order of processing may be changed in a range in which appropriate processing is performed.

[0044] Each of the storage unit 58 and other storage devices in the embodiments of the present disclosure may be provided anywhere in a range in which appropriate information is transmitted and received. Further, each of the storage unit 58 and the other storage devices may be present in a plurality in a range in which appropriate information is transmitted and received, and data may be stored in a distributed manner.

[0045] The process of the processing by the control device 50 described above is stored in the form of a program in a recording medium that can be read by a computer 200, and the computer 200 reads out and executes this program, so that the processing is performed. A specific example of the computer 200 will be described below.

[0046] As shown in FIG. 8, the computer 200 includes a CPU 101, a main memory 102, a storage 103, and an interface 104.

[0047] For example, the control device 50 is mounted on the computer 200. Further, the operation of each processing unit described above is stored in the storage 103 in the form of a program. The CPU 101 reads out the program from the storage 103, loads the program into the main memory 102, and performs the above-described processing according to the program. Further, the CPU 101 secures a storage area corresponding to the storage unit 58 described above in the main memory 102 according to the program.

[0048] Examples of the storage 103 include a hard disk drive (HDD), a solid-state drive (SSD), a magnetic disk, a magneto-optical disk, a compact disc read-only memory (CD-ROM), a digital versatile disc read-only memory (DVD-ROM), and a semiconductor memory. The storage 103 may be an internal medium directly connected to a bus of the computer 200 or may be an external medium connected to the computer 200 via the interface 104 or a communication line. Further, when this program is delivered to the computer 200 through the communication line, the computer 200 to which the program is delivered may load the program into the main memory 102 and may perform the processing. The storage 103 is a non-transitory tangible storage medium.

[0049] Further, the above program may implement some of the above-mentioned functions. Furthermore, the program may be a so-called differential file (differential program) that can realize the above functions in combination with a program already recorded in the computer 200.

[0050] A custom large scale integrated circuit (LSI) such as a programmable logic device (PLD), an application specific integrated circuit (ASIC), a graphics processing unit (GPU), and a processing device similar thereto may be provided in addition to the above-described configuration or instead of the above-described configuration. As examples of the PLD, a programmable array logic (PAL), a generic array logic (GAL), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA) can be given. In this case, a part or all of the functions realized by the processor may be realized by the integrated circuit.<Additional Notes>

[0051] The air conditioner 1 described in each embodiment is understood as follows, for example. (1) An air conditioner 1 according to a first aspect includes an indoor heat exchanger 11, an outdoor heat exchanger 12, a gas pipe 13 that connects the indoor heat exchanger 11 and the outdoor heat exchanger 12 and through which a gas-phase refrigerant flows, a compressor 14 that is disposed on the gas pipe 13, a liquid pipe 15 that connects the indoor heat exchanger 11 and the outdoor heat exchanger 12, through which a liquid-phase or gas-liquid two-phase refrigerant flows, and that forms a circulation circuit together with the gas pipe 13, an expansion valve 16 that is provided on the liquid pipe 15, and a four-way valve that switches a flow direction of the refrigerant between a cooling operation and a heating operation, in which the air conditioner 1 further includes a first operation valve 20 that is provided between the compressor 14 and the indoor heat exchanger 11 on the gas pipe 13, a second operation valve 30 that is provided between the expansion valve 16 and the indoor heat exchanger 11 on the liquid pipe 15, a first temperature measurement unit 41 that measures a temperature of the indoor heat exchanger 11, a second temperature measurement unit 42 that measures a temperature of the outdoor heat exchanger 12, a third temperature measurement unit 43 that measures an indoor temperature, a fourth temperature measurement unit 44 that measures an outdoor temperature, and a control device 50, the control device 50 includes an operation determination unit 51 that determines whether the air conditioner 1 is in the cooling operation or the heating operation, a first comparison unit 52 that compares the temperature of the outdoor heat exchanger 12 with the outdoor temperature in a case of the cooling operation, and a first determination unit 53 that determines a state of each device when the temperature of the outdoor heat exchanger 12 is lower than the outdoor temperature, and the first determination unit 53 determines that a switching failure of the four-way valve has occurred when the temperature of the indoor heat exchanger 11 is equal to or higher than a predetermined first threshold value, and determines that the first operation valve 20 and the second operation valve 30 are in a closed state when the temperature of the indoor heat exchanger 11 is lower than the first threshold value.

[0052] According to the above-described configuration, the first determination unit 53 can determine the switching failure of the four-way valve and the closing of the first operation valve 20 and the second operation valve 30 based on the temperature of the indoor heat exchanger 11, the temperature of the outdoor heat exchanger 12, the indoor temperature, and the outdoor temperature.

[0053] (2) An air conditioner 1 according to a second aspect is the air conditioner 1 according to (1), in which the control device 50 further includes a second comparison unit 54 that compares the temperature of the indoor heat exchanger 11 with the indoor temperature when the first comparison unit 52 determines that the temperature of the outdoor heat exchanger 12 is higher than the outdoor temperature, and a second determination unit 55 that determines the state of each device by comparing the temperature of the indoor heat exchanger 11 with a predetermined second threshold value when the temperature of the indoor heat exchanger 11 is higher than the indoor temperature, and the second determination unit 55 determines that the first operation valve 20 is in the closed state when the temperature of the indoor heat exchanger 11 is higher than the second threshold value, and determines that the first operation valve 20 and the second operation valve 30 are in the closed state when the temperature of the indoor heat exchanger 11 is lower than the second threshold value.

[0054] According to the above-described configuration, the second determination unit 55 can determine whether the first operation valve 20 is in the closed state or the first operation valve 20 and the second operation valve 30 are in the closed state based on the temperature of the indoor heat exchanger 11 and the indoor temperature.

[0055] (3) An air conditioner 1 according to a third aspect is the air conditioner 1 according to (2), in which the control device 50 further includes a third determination unit 56 that determines the state of each device by comparing the temperature of the indoor heat exchanger 11 with a predetermined third threshold value and a fourth threshold value that is a value higher than the third threshold value, when the second comparison unit 54 determines that the temperature of the indoor heat exchanger 11 is lower than the indoor temperature, and the third determination unit 56 determines that the second operation valve 30 is in the closed state or in a normal operation state when the temperature of the indoor heat exchanger 11 is lower than the third threshold value, determines that a filling amount of the refrigerant is reduced when the temperature of the indoor heat exchanger 11 is higher than the third threshold value and lower than the fourth threshold value, and determines that the first operation valve 20 and the second operation valve 30 are in the closed state when the temperature of the indoor heat exchanger 11 is higher than the fourth threshold value.

[0056] According to the above-described configuration, the third determination unit 56 can determine whether the second operation valve 30 is in the closed state or in the normal operation state, whether the filling amount of the refrigerant is reduced, and whether the first operation valve 20 and the second operation valve 30 are in the closed state based on the temperature of the indoor heat exchanger 11 and the indoor temperature.

[0057] (4) An air conditioner 1 according to a fourth aspect is the air conditioner 1 according to (3), in which the control device 50 further includes a fourth determination unit 57 that determines whether the second operation valve 30 is in the closed state or in the normal operation state when the third determination unit 56 determines that the temperature of the indoor heat exchanger 11 is lower than the third threshold value, and the fourth determination unit 57 determines that the second operation valve 30 is in the closed state when the compressor 14 operates for a predetermined time in a state where a rotation speed of the compressor 14 is higher than a predetermined rotation speed threshold value and when the temperature of the indoor heat exchanger 11 is higher than a predetermined fifth threshold value.

[0058] According to the above-described configuration, when it is determined by the third determination unit 56 that the temperature of the indoor heat exchanger 11 is lower than the third threshold value, the compressor 14 can be operated at a predetermined rotation speed for a certain time, and then the fourth determination unit 57 can determine whether the second operation valve 30 is in the closed state or in the normal operation state based on the comparison with a further threshold value.

[0059] (5) An air conditioner 1 according to a fifth aspect includes an indoor heat exchanger 11, an outdoor heat exchanger 12, a gas pipe 13 that connects the indoor heat exchanger 11 and the outdoor heat exchanger 12 and through which a gas-phase refrigerant flows, a compressor 14 that is disposed on the gas pipe 13, a liquid pipe 15 that connects the indoor heat exchanger 11 and the outdoor heat exchanger 12, through which a liquid-phase refrigerant flows, and that forms a circulation circuit together with the gas pipe 13, an expansion valve 16 that is provided on the liquid pipe 15, and a four-way valve that switches a flow direction of the refrigerant between a cooling operation and a heating operation, in which the air conditioner 1 further includes a first operation valve 20 that is provided between the compressor 14 and the indoor heat exchanger 11 on the gas pipe 13, a second operation valve 30 that is provided between the expansion valve 16 and the indoor heat exchanger 11 on the liquid pipe 15, a first temperature measurement unit 41 that measures a temperature of the indoor heat exchanger 11, a second temperature measurement unit 42 that measures a temperature of the outdoor heat exchanger 12, a third temperature measurement unit 43 that measures an indoor temperature, a fourth temperature measurement unit 44 that measures an outdoor temperature, and a control device 50, the control device 50 includes an operation determination unit 51 that determines whether the air conditioner 1 is in the cooling operation or the heating operation, a first comparison unit 52 that compares the temperature of the outdoor heat exchanger 12 with the outdoor temperature in a case of the heating operation, and a first determination unit 53 that determines a state of each device when the temperature of the outdoor heat exchanger 12 is higher than the outdoor temperature, and the first determination unit 53 determines that a switching failure of the four-way valve has occurred when the temperature of the indoor heat exchanger 11 is lower than a predetermined first threshold value.

[0060] According to the above-described configuration, the first determination unit 53 can determine the switching failure of the four-way valve based on the temperature of the indoor heat exchanger 11, the temperature of the outdoor heat exchanger 12, the indoor temperature, and the outdoor temperature.

[0061] (6) An air conditioner 1 according to a sixth aspect is the air conditioner 1 according to (5), in which the control device 50 further includes a second comparison unit 54 that compares the temperature of the indoor heat exchanger 11 with the indoor temperature when the first comparison unit 52 determines that the temperature of the outdoor heat exchanger 12 is lower than the outdoor temperature, and a second determination unit 55 that determines the state of each device by comparing the temperature of the indoor heat exchanger 11 with a predetermined second threshold value when the temperature of the indoor heat exchanger 11 is lower than the indoor temperature, and the second determination unit 55 determines that the first operation valve 20 and the second operation valve 30 are in a closed state when the temperature of the indoor heat exchanger 11 is higher than the second threshold value, and determines that the first operation valve 20 is in the closed state when the temperature of the indoor heat exchanger 11 is equal to or lower than the second threshold value.

[0062] According to the above-described configuration, the second determination unit 55 can determine whether the first operation valve 20 is in the closed state or the first operation valve 20 and the second operation valve 30 are in the closed state based on the temperature of the indoor heat exchanger 11 and the indoor temperature.

[0063] (7) An air conditioner 1 according to a seventh aspect is the air conditioner 1 according to (6), in which the control device 50 further includes a third determination unit 56 that determines the state of each device by comparing the temperature of the indoor heat exchanger 11 with a predetermined third threshold value and a fourth threshold value that is a value higher than the third threshold value, when the second comparison unit 54 determines that the temperature of the indoor heat exchanger 11 is higher than the indoor temperature, and the third determination unit 56 determines that the first operation valve 20 and the second operation valve 30 are in the closed state when the temperature of the indoor heat exchanger 11 is lower than the third threshold value, determines that a filling amount of the refrigerant is reduced when the temperature of the indoor heat exchanger 11 is higher than the third threshold value and lower than the fourth threshold value, and determines that the second operation valve 30 is in the closed state or in a normal operation state when the temperature of the indoor heat exchanger 11 is higher than the fourth threshold value.

[0064] According to the above-described configuration, the third determination unit 56 can determine whether the second operation valve 30 is in the closed state or in the normal operation state, whether the filling amount of the refrigerant is reduced, and whether the first operation valve 20 and the second operation valve 30 are in the closed state based on the temperature of the indoor heat exchanger 11 and the indoor temperature.

[0065] (8) An air conditioner 1 according to an eighth aspect is the air conditioner 1 according to (7), in which the control device 50 further includes a fourth determination unit 57 that determines whether the second operation valve 30 is in the closed state or in the normal operation state when the third determination unit 56 determines that the temperature of the indoor heat exchanger 11 is higher than the fourth threshold value, and the fourth determination unit 57 determines that the second operation valve 30 is in the closed state when the compressor 14 operates for a predetermined time in a state where a rotation speed of the compressor 14 is higher than a predetermined rotation speed threshold value and when the temperature of the outdoor heat exchanger 12 is lower than a predetermined sixth threshold value.

[0066] According to the above-described configuration, when it is determined by the third determination unit 56 that the temperature of the indoor heat exchanger 11 is higher than the fourth threshold value, the compressor 14 can be operated at a predetermined rotation speed for a certain time, and then the fourth determination unit 57 can determine whether the second operation valve 30 is in the closed state or in the normal operation state based on the comparison with a further threshold value.Industrial Applicability

[0067] According to the present disclosure, it is possible to provide an air conditioner capable of more finely determining a type of an abnormal state.Reference Signs List

[0068] 1: air conditioner 10: refrigeration cycle circuit 11: indoor heat exchanger 12: outdoor heat exchanger 13: gas pipe 14: compressor 15: liquid pipe 16: expansion valve 20: first operation valve 30: second operation valve 41: first temperature measurement unit 42: second temperature measurement unit 43: third temperature measurement unit 44: fourth temperature measurement unit 50: control device 51: operation determination unit 52: first comparison unit 53: first determination unit 54: second comparison unit 55: second determination unit 56: third determination unit 57: fourth determination unit 58: storage unit 101: CPU 102: main memory 103: storage 104: interface 200: computer

Claims

1. An air conditioner comprising: an indoor heat exchanger; an outdoor heat exchanger; a gas pipe that connects the indoor heat exchanger and the outdoor heat exchanger and through which a gas-phase refrigerant flows; a compressor that is disposed on the gas pipe; a liquid pipe that connects the indoor heat exchanger and the outdoor heat exchanger, through which a liquid-phase or gas-liquid two-phase refrigerant flows, and that forms a circulation circuit together with the gas pipe; an expansion valve that is provided on the liquid pipe; and a four-way valve that switches a flow direction of the refrigerant between a cooling operation and a heating operation, wherein the air conditioner further includes a first operation valve that is provided between the compressor and the indoor heat exchanger on the gas pipe, a second operation valve that is provided between the expansion valve and the indoor heat exchanger on the liquid pipe, a first temperature measurement unit that measures a temperature of the indoor heat exchanger, a second temperature measurement unit that measures a temperature of the outdoor heat exchanger, a third temperature measurement unit that measures an indoor temperature, a fourth temperature measurement unit that measures an outdoor temperature, and a control device, the control device includes an operation determination unit that determines whether the air conditioner is in the cooling operation or the heating operation, a first comparison unit that compares the temperature of the outdoor heat exchanger with the outdoor temperature in a case of the cooling operation, and a first determination unit that determines a state of each device when the temperature of the outdoor heat exchanger is lower than the outdoor temperature, and the first determination unit determines that a switching failure of the four-way valve has occurred when the temperature of the indoor heat exchanger is equal to or higher than a predetermined first threshold value, and determines that the first operation valve and the second operation valve are in a closed state when the temperature of the indoor heat exchanger is lower than the first threshold value.

2. The air conditioner according to Claim 1, wherein the control device further includes a second comparison unit that compares the temperature of the indoor heat exchanger with the indoor temperature when the first comparison unit determines that the temperature of the outdoor heat exchanger is higher than the outdoor temperature, and a second determination unit that determines the state of each device by comparing the temperature of the indoor heat exchanger with a predetermined second threshold value when the temperature of the indoor heat exchanger is higher than the indoor temperature, and the second determination unit determines that the first operation valve is in the closed state when the temperature of the indoor heat exchanger is higher than the second threshold value, and determines that the first operation valve and the second operation valve are in the closed state when the temperature of the indoor heat exchanger is lower than the second threshold value.

3. The air conditioner according to Claim 2, wherein the control device further includes a third determination unit that determines the state of each device by comparing the temperature of the indoor heat exchanger with a predetermined third threshold value and a fourth threshold value that is a value higher than the third threshold value, when the second comparison unit determines that the temperature of the indoor heat exchanger is lower than the indoor temperature, and the third determination unit determines that the second operation valve is in the closed state or in a normal operation state when the temperature of the indoor heat exchanger is lower than the third threshold value, determines that a filling amount of the refrigerant is reduced when the temperature of the indoor heat exchanger is higher than the third threshold value and lower than the fourth threshold value, and determines that the first operation valve and the second operation valve are in the closed state when the temperature of the indoor heat exchanger is higher than the fourth threshold value.

4. The air conditioner according to Claim 3, wherein the control device further includes a fourth determination unit that determines whether the second operation valve is in the closed state or in the normal operation state when the third determination unit determines that the temperature of the indoor heat exchanger is lower than the third threshold value, and the fourth determination unit determines that the second operation valve is in the closed state when the compressor operates for a predetermined time in a state where a rotation speed of the compressor is higher than a predetermined rotation speed threshold value and when the temperature of the indoor heat exchanger is higher than a predetermined fifth threshold value.

5. An air conditioner comprising: an indoor heat exchanger; an outdoor heat exchanger; a gas pipe that connects the indoor heat exchanger and the outdoor heat exchanger and through which a gas-phase refrigerant flows; a compressor that is disposed on the gas pipe; a liquid pipe that connects the indoor heat exchanger and the outdoor heat exchanger, through which a liquid-phase refrigerant flows, and that forms a circulation circuit together with the gas pipe; an expansion valve that is provided on the liquid pipe; and a four-way valve that switches a flow direction of the refrigerant between a cooling operation and a heating operation, wherein the air conditioner further includes a first operation valve that is provided between the compressor and the indoor heat exchanger on the gas pipe, a second operation valve that is provided between the expansion valve and the indoor heat exchanger on the liquid pipe, a first temperature measurement unit that measures a temperature of the indoor heat exchanger, a second temperature measurement unit that measures a temperature of the outdoor heat exchanger, a third temperature measurement unit that measures an indoor temperature, a fourth temperature measurement unit that measures an outdoor temperature, and a control device, the control device includes an operation determination unit that determines whether the air conditioner is in the cooling operation or the heating operation, a first comparison unit that compares the temperature of the outdoor heat exchanger with the outdoor temperature in a case of the heating operation, and a first determination unit that determines a state of each device when the temperature of the outdoor heat exchanger is higher than the outdoor temperature, and the first determination unit determines that a switching failure of the four-way valve has occurred when the temperature of the indoor heat exchanger is lower than a predetermined first threshold value.

6. The air conditioner according to Claim 5, wherein the control device further includes a second comparison unit that compares the temperature of the indoor heat exchanger with the indoor temperature when the first comparison unit determines that the temperature of the outdoor heat exchanger is lower than the outdoor temperature, and a second determination unit that determines the state of each device by comparing the temperature of the indoor heat exchanger with a predetermined second threshold value when the temperature of the indoor heat exchanger is lower than the indoor temperature, and the second determination unit determines that the first operation valve and the second operation valve are in a closed state when the temperature of the indoor heat exchanger is higher than the second threshold value, and determines that the first operation valve is in the closed state when the temperature of the indoor heat exchanger is equal to or lower than the second threshold value.

7. The air conditioner according to Claim 6, wherein the control device further includes a third determination unit that determines the state of each device by comparing the temperature of the indoor heat exchanger with a predetermined third threshold value and a fourth threshold value that is a value higher than the third threshold value, when the second comparison unit determines that the temperature of the indoor heat exchanger is higher than the indoor temperature, and the third determination unit determines that the first operation valve and the second operation valve are in the closed state when the temperature of the indoor heat exchanger is lower than the third threshold value, determines that a filling amount of the refrigerant is reduced when the temperature of the indoor heat exchanger is higher than the third threshold value and lower than the fourth threshold value, and determines that the second operation valve is in the closed state or in a normal operation state when the temperature of the indoor heat exchanger is higher than the fourth threshold value.

8. The air conditioner according to Claim 7, wherein the control device further includes a fourth determination unit that determines whether the second operation valve is in the closed state or in the normal operation state when the third determination unit determines that the temperature of the indoor heat exchanger is higher than the fourth threshold value, and the fourth determination unit determines that the second operation valve is in the closed state when the compressor operates for a predetermined time in a state where a rotation speed of the compressor is higher than a predetermined rotation speed threshold value and when the temperature of the outdoor heat exchanger is lower than a predetermined sixth threshold value.

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