JP6656490B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner.

  In order to prevent global warming, it is required to reduce the GWP (Global Warming Potential) value of a refrigerant used for refrigeration and air conditioning equipment. Since a refrigerant having a low GWP value has slight flammability (combustibility), laws and standards have been enacted that require safety measures against refrigerant leakage in order to safely use the slightly flammable A2L refrigerant. ing.

  When a refrigerant leak occurs, it is necessary to detect the refrigerant leak and take necessary measures to prevent the leaked refrigerant from burning, and there is an air conditioner provided with a refrigerant detection sensor for detecting the refrigerant leak. This refrigerant detection sensor has a lifetime and needs to be replaced or maintained in a predetermined period.

  The refrigeration cycle apparatus disclosed in Patent Document 1 is configured such that, when the integrated energization time to the refrigerant detection means is equal to or longer than the first threshold time, the notification unit is notified of the abnormality and the blower fan is operated. Yes. " Further, it states that "the control unit stops the compressor of the refrigerant circuit when the integrated energization time becomes equal to or longer than the first threshold time".

Japanese Patent No. 6143977

  In the technology described in Patent Document 1, the first threshold time is a time for notifying an abnormality. However, it is difficult to determine whether the abnormality is actually abnormal by the first threshold time. This is because it is doubtful whether the life of the sensors can be determined by the first threshold time.

  An object of the present invention is to solve the above-described problem, and an object of the present invention is to provide an air conditioner that can consider the life of a refrigerant detection sensor.

In order to solve the above-described problems, an air conditioner according to the present invention includes a refrigerant circuit in which a refrigerant circulates, a refrigerant detection sensor that detects leakage of the refrigerant, and a control unit that controls the refrigerant circuit. parts, said the refrigerant detection life regarding the first notification regarding the life of the refrigerant detection sensor when the second period has elapsed is shorter than the first period of the sensor, the abnormality of the refrigerant detection sensor after the first period has elapsed Is detected, a second notification about the life of the refrigerant detection sensor is issued, and when a predetermined period has elapsed from the second notification , the air conditioning operation is forcibly disabled . Other aspects of the present invention will be described in embodiments described later.

  According to the present invention, the life of the refrigerant detection sensor can be considered.

It is a figure showing the whole air conditioner composition. It is a figure showing a refrigeration cycle system of an air conditioner. It is a figure showing the front of the floor-standing type indoor unit with which an air conditioner is provided. It is a figure showing the longitudinal section of a floor standing type indoor unit with which an air conditioner is provided. It is a figure showing the relation between a refrigerant detection sensor and a control part. It is a figure which shows the installation situation of a refrigerant | coolant detection sensor. It is a figure showing composition of a control part of an air conditioner. It is a figure showing period management by a control part. It is a flowchart which shows the life management process of a refrigerant | coolant detection sensor. It is a figure showing an example of an abnormality judgment value of a refrigerant detection sensor.

An embodiment for carrying out the present invention will be described in detail with reference to the drawings as appropriate.
FIG. 1 is a diagram showing the overall configuration of the air conditioner. The air conditioner AC includes an indoor unit 100 and an outdoor unit 200. The indoor unit 100 and the outdoor unit 200 are connected by a refrigerant pipe and a control line. The indoor unit 100 includes a control unit 60, an air-conditioning control terminal 22 (remote controller), and a refrigerant detection sensor 30 that detects refrigerant leakage. The outdoor unit 200 has a control unit 50. As the refrigerant circulating between the indoor unit 100 and the outdoor unit 200, a slightly flammable (A2L) refrigerant such as R32, R1234yf, and R1234ze is used.

  FIG. 2 is a diagram illustrating a refrigeration cycle system of the air conditioner. In FIG. 2, the direction in which the refrigerant flows during the heating operation is indicated by a solid line, and the direction in which the refrigerant flows during the cooling operation is indicated by a broken line. The air conditioner AC is a device that performs air conditioning such as heating and cooling. As shown in FIG. 2, the air conditioner AC includes a refrigerant circuit 10, an outdoor fan Fo, an indoor fan Fi, blocking valves PV1 and PV2, a refrigerant detection sensor 30, and controllers 50 and 60. ing.

  The refrigerant circuit 10 is a circuit in which the refrigerant circulates in a refrigeration cycle (heat pump cycle). As shown in FIG. 2, the refrigerant circuit 10 includes a compressor 11, a four-way valve 12, an outdoor heat exchanger 13, an expansion valve 14, and an indoor heat exchanger 15.

  The compressor 11 is a device that compresses a gaseous refrigerant. The type of the compressor 11 is not particularly limited, and a compressor of a scroll type, a piston type, a rotary type, a screw type, a centrifugal type, or the like is used. Although not shown in FIG. 1, an accumulator for separating the refrigerant into gas and liquid is provided on the suction side of the compressor 11.

  The outdoor heat exchanger 13 is a heat exchanger that exchanges heat between the refrigerant flowing through the heat transfer tube (not shown) and the outside air sent from the outdoor fan Fo. The outdoor fan Fo is a fan that sends outside air to the outdoor heat exchanger 13, and is installed near the outdoor heat exchanger 13.

  The indoor heat exchanger 15 exchanges heat between the refrigerant flowing through the heat transfer tube 15a (see FIG. 4) and the indoor air (air in the air-conditioned space) sent from the indoor fan Fi. It is a vessel. The indoor fan Fi is a fan that sends indoor air to the indoor heat exchanger 15 and is installed near the indoor heat exchanger 15.

  The expansion valve 14 is a valve for reducing the pressure of the refrigerant condensed in the “condenser” (one of the outdoor heat exchanger 13 and the indoor heat exchanger 15). The refrigerant decompressed by the expansion valve 14 is guided to an “evaporator” (the other of the outdoor heat exchanger 13 and the indoor heat exchanger 15).

  The four-way valve 12 is a valve that switches the flow path of the refrigerant according to the operation mode of the air conditioner AC. For example, during the cooling operation (see the dashed arrow in FIG. 2), the compressor 11, the outdoor heat exchanger 13 (condenser), the expansion valve 14, and the indoor heat exchanger 15 (evaporator) are connected to the four-way valve 12 The refrigerant circulates in the refrigeration cycle in the refrigerant circuit 10 which is sequentially connected in a ring through the refrigerant circuit.

  During the heating operation (see the solid arrow in FIG. 2), the compressor 11, the indoor heat exchanger 15 (condenser), the expansion valve 14, and the outdoor heat exchanger 13 (evaporator) are connected to the four-way valve 12 The refrigerant circulates in the refrigeration cycle in the refrigerant circuit 10 which is sequentially connected in a ring through the refrigerant circuit. As described above, in the refrigerant circuit 10, the refrigerant circulates in the refrigeration cycle through the compressor 11, the "condenser", the expansion valve 14, and the "evaporator" in this order.

  In the example shown in FIG. 2, the compressor 11, the four-way valve 12, the outdoor heat exchanger 13, the expansion valve 14, the outdoor fan Fo, and a control unit 50 described later are provided in the outdoor unit 200. On the other hand, in addition to the indoor heat exchanger 15 and the indoor fan Fi, the indoor unit 100 includes a refrigerant detection sensor 30 and a control unit 60 described later.

  The blocking valves PV1 and PV2 are valves that are opened after the installation work of the air conditioner AC to distribute the refrigerant sealed in the outdoor unit 200 to the entire refrigerant circuit 10 up to that time.

  The refrigerant detection sensor 30 is a sensor that detects leakage of the refrigerant in the refrigerant circuit 10, and is installed at a predetermined location in the indoor unit 100 where leakage of the refrigerant is easily detected. The refrigerant detection sensor 30 outputs a refrigerant leakage detection signal (for example, the output voltage in FIG. 10) corresponding to the concentration of the refrigerant detected by the refrigerant detection sensor 30 to the control unit 60.

  The control units 50 and 60 are, for example, a microcomputer (microcomputer), and include electronic circuits such as a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and various interfaces (not shown). It is composed of Then, the program stored in the ROM is read and expanded in the RAM, and the CPU executes various processes. The control unit 50 appropriately controls the compressor 11, the expansion valve 14, the outdoor fan Fo, and the like.

  The control unit 60 is, for example, a microcomputer, and is connected to the control unit 50 via a control line. The control unit 60 appropriately controls the indoor fan Fi and the like based on a signal input from the control unit 50 and the air conditioning control terminal 22 (see FIG. 3), a detection result of the refrigerant detection sensor 30, and the like. Next, as an example, the configuration of the floor-standing type indoor unit 100 will be described.

  FIG. 3 is a diagram illustrating a front surface of a floor-standing indoor unit included in the air conditioner. As shown in FIG. 3, the indoor unit 100 includes a cabinet 21 and an air conditioning control terminal 22 (remote control). The cabinet 21 is a housing that houses the indoor heat exchanger 15 (see FIG. 4), the indoor fan Fi (see FIG. 4), and the like. The cabinet 21 includes a front panel 21a, a bottom base 21b, an air inlet h1, and an air outlet h2.

  The front panel 21a is a part of the front plate of the cabinet 21 and is removable. The bottom base 21b is a bottom plate of the cabinet 21. The air suction port h1 is an opening for guiding air into the interior of the cabinet 21, and is provided below the front panel 21a. The air outlet h2 is an opening for blowing air with conditioned temperature and humidity into the air-conditioned space, and is provided above the front panel 21a.

  The air-conditioning control terminal 22 is for performing switching of operation / stop, change of set temperature, change of operation mode, and the like by a user operation, and is provided at the center of the front panel 21a.

  FIG. 4 is a diagram showing a vertical section of a floor-standing indoor unit provided in the air conditioner. In the example shown in FIG. 4, the indoor heat exchanger 15, the drain pan 23, the heat insulating plate 24 and the like are installed in an upper space in the cabinet 21. In addition, an indoor fan Fi, a bell mouth 25, an electric component box 44, and the like are installed in a lower space in the cabinet 21.

  The drain pan 23 receives condensed water dripping from the indoor heat exchanger 15. The condensed water received by the drain pan 23 is discharged to the outside via the drain pipe K1 and the like. In addition, another drain pipe (not shown) is connected to the downstream end k of the drain pipe K1 via a pipe intake hole i provided in a side plate or the like of the cabinet 21. Another refrigerant pipe is also connected to a connection j of the refrigerant pipe J1 for guiding the refrigerant to the indoor heat exchanger 15 via a pipe intake hole i.

  The heat insulating plate 24 is a plate for insulating the space between the space subject space and the inside of the cabinet 21. The heat insulating plate 24 is provided between the indoor heat exchanger 15 and the front panel 21a. The bell mouth 25 guides the flow of air from the indoor fan Fi (for example, a centrifugal fan), and is installed on the blowout side of the indoor fan Fi.

  The electric component box 44 is a box that accommodates the control unit 60 (see FIG. 1), and is installed below the drain pan 23.

  Further, the above-described refrigerant detection sensor 30 is provided on the bottom base 21b. This refrigerant detection sensor 30 includes a sensor case 31 that houses circuit components and the like. For example, when the refrigerant leaks from near the connection j of the refrigerant pipe J1 (unconnected state in FIG. 3), the gas refrigerant having a specific gravity higher than that of air sinks and accumulates at the bottom. When the concentration of the gas refrigerant is equal to or higher than the predetermined threshold, the refrigerant detection sensor 30 detects refrigerant leakage.

  FIG. 5 is a diagram illustrating a relationship between the refrigerant detection sensor and the control unit. In FIG. 5, the illustration of the electrical connection between the control unit 60 and other devices (such as the control unit 50 and the air conditioning control terminal 22 shown in FIG. 1) is omitted. The refrigerant detection sensor 30 includes a sensor unit 30a and a sensor board 30b that outputs an output voltage or the like detected by the sensor unit 30a.

  The sensor unit 30a is an element having sensitivity to the concentration of the refrigerant. That is, the sensor unit 30a outputs a signal (analog signal) indicating the concentration of the refrigerant. As such a sensor unit 30a, an element of a contact combustion type, an electrochemical type, or the like can be used in addition to a semiconductor type or an infrared type. Then, a gas refrigerant or the like is introduced into the sensor unit 30a through the net Q shown in FIG.

  The sensor board 30b outputs a refrigerant detection signal (for example, the output voltage Vout in FIG. 10) based on a signal input from the sensor unit 30a, and electrically connects the control unit 60 to the control unit 60 via a plurality of wires m. Connected. The control unit 60 supplies a circuit voltage (for example, 5 V) to the sensor substrate 30b.

  If the output voltage Vout of the refrigerant detection sensor 30 falls within a predetermined range (for example, the voltage V3 or more and the voltage V4 or less in FIG. 10), the control unit 60 determines that there is refrigerant leakage, and air-conditions that fact. The control terminal 22 (see FIG. 3) has a function of notifying by display or sound. In addition, when the leakage of the flammable refrigerant (for example, the refrigerant R32) is detected, the control unit 60 may drive the indoor fan Fi (see FIG. 4) even while the air conditioning operation is stopped. . As a result, the gas refrigerant that has settled near the floor of the space to be air-conditioned is diffused, so that the concentration of the refrigerant can be prevented from locally increasing.

  FIG. 6 is a diagram illustrating a state of installation of the refrigerant detection sensor. As described above, in the floor-mounted indoor unit 100 (see FIG. 4), the refrigerant detection sensor 30 is installed on the bottom base 21b. Note that a rib 211b is formed at a position where the refrigerant detection sensor 30 is installed on the bottom base 21b. The rib 211b extends upward from the bottom base 21b, and has a frame shape (for example, a square frame shape) in plan view.

  The thin lid-shaped sensor case 31 is fixed with bolts F so as to cover the ribs 211b. As shown in FIG. 6, the sensor case 31 includes a flat base 31a and a side wall 31b extending downward from a peripheral edge of the base 31a.

  The above-described refrigerant detection sensor 30 is provided on the back surface (inner surface) of the base portion 31a. In other words, the refrigerant detection sensor 30 is provided on the inner ceiling surface of the sensor case 31.

  The sensor board 30b is fixed to the base 31a by a claw member (not shown), a screw, or the like, but the sensor board 30b can be removed from the base 31a. Thus, for example, before the end of the life of the refrigerant detection sensor 30, the sensor substrate 30b on which the sensor unit 30a is mounted can be removed from the sensor case 31 and replaced with a new one.

  As shown in FIG. 6, a predetermined gap is provided between the sensor case 31 and the rib 211b in the horizontal and vertical directions. Further, a plurality of slits 31c (refrigerant intake) are provided in the side wall 31b of the sensor case 31. In the example shown in FIG. 6, a number of slits 31c are provided over substantially the entire circumference of the side wall 31b.

  When the refrigerant leaks from the refrigerant circuit 10 (see FIG. 2), the vaporized gas refrigerant enters the sensor case 31 through the slit 31c. Even if a large amount of condensed water overflows from the drain pan 23 (see FIG. 3), the condensed water flowing down to the bottom base 21b is blocked by the rib 211b. Thereby, it is possible to prevent the condensed water from adhering to the sensor unit 30a mounted on the sensor substrate 30b.

  Incidentally, it is rare that the refrigerant leaks or the condensed water overflows from the drain pan 23 (see FIG. 3). However, in FIG. 5, “gas refrigerant” or “condensed water” Is described.

  As described above, the refrigerant detection sensor 30 is replaced before the life of the sensor unit 30a expires. When replacing the refrigerant detection sensor 30, the maintenance worker removes the sensor case 31 from the bottom base 21b, further removes the refrigerant detection sensor 30 from the sensor case 31, and then replaces the new refrigerant detection sensor 30 with the sensor case 31. Installed in

  FIG. 7 is a diagram illustrating a configuration of a control unit of the indoor unit. The control unit 60 includes an air conditioning control unit 61 that performs air conditioning control in accordance with an instruction from the air conditioning control terminal 22, a refrigerant leak determination unit 62 that determines whether there is a refrigerant leak based on an output of the refrigerant detection sensor 30, a refrigerant detection It has a refrigerant detection sensor life management unit 63 that manages the life of the sensor 30, a notification unit 66 that issues various notification instructions to the air conditioning control terminal 22, and a storage unit 69 that stores setting values and the like. The refrigerant detection sensor life management unit 63 includes an operation time integration unit 64 and a refrigerant detection sensor abnormality / failure monitoring unit 65.

The storage unit 69 includes, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The storage unit 69, the first period T1, which will be described in FIG. 8, the second period T2, the predetermined time period Tc, the voltage _{V 1,} V _{2, V} 3, which will be described in FIG. _{10, V 4, V 5,} V 6 , etc. The judgment value is stored.

  FIG. 8 is a diagram illustrating period management by the control unit. FIG. 8 shows a monitoring state until the life of the refrigerant detection sensor 30 after the start of the operation of the indoor unit 100 and a replacement time of the sensor. The first period T1 (time Ts to Tb) is a period that indicates the initial expected life of the refrigerant detection sensor 30. The second period T2 (time ts to ta) is a period shorter than the first period T1. Time ta is a time for notifying that the refrigerant detection sensor 30 is approaching the end of its life. Further, the predetermined period Tc (time tc to td) is a period from the detection of the sensor abnormality of the refrigerant detection sensor 30 (time tc) after the first period elapses until the operation is forcibly stopped. The third period T3 (time ts to td) is a period from the start of the operation of the indoor unit 100 to the forcible stop of the operation.

  When the air conditioning operation is started, the operation time is accumulated. When the operation time increases and a predetermined second period elapses (time ta), the air-conditioning control terminal indicates that the expected life of the refrigerant detection sensor 30 is approaching and that the refrigerant detection sensor 30 needs to be prepared for replacement. An advance notice is displayed on the display 22. The user checks the display and arranges replacement of the refrigerant detection sensor 30. Since the time between the second period and the first period (time ta to tb) is set to a time during which arrangements necessary for replacement of the refrigerant detection sensor 30 can be made, the user has enough time to operate the refrigerant detection sensor 30. There is an effect that the exchange can be performed. Furthermore, it is desirable to replace the refrigerant detection sensor 30 before the operation time increases and reaches a predetermined first period corresponding to the expected life of the refrigerant detection sensor 30.

  When the operation time elapses a predetermined first period (time tb), a first life notification that the estimated life of the refrigerant detection sensor 30 has been reached is displayed on the display. Originally, the expected life of the refrigerant detection sensor 30 is reached, and the detection accuracy cannot be guaranteed. Therefore, the user needs to replace the refrigerant detection sensor 30 immediately.

  When the operation time further elapses and the sensor abnormality of the refrigerant detection sensor 30 is detected (time tc), the second life notification is displayed on the display of the air conditioning control terminal 22. This prompts the sensor replacement immediately.

  When the operation is further continued and a third period T3 elapses after a predetermined period Tc elapses after the sensor abnormality is detected (time td), any further operation is performed when a refrigerant leak occurs. The operation of the air conditioner AC is forcibly stopped because the sensor 30 may not be able to detect it. Then, it is possible to prompt the user to replace the refrigerant detection sensor 30 and to ensure safety.

Patent Literature 1 describes that “the control unit stops the compressor of the refrigerant circuit when the integrated energization time is equal to or longer than the first threshold time”. It is characterized in that the operation of the air conditioner AC is not stopped immediately even when the detection sensor 30 reaches the expected life. As a reason,
(1) The life of the individual refrigerant detection sensors 30 varies from one unit to another, and a failure does not always occur at the estimated life. For example, a sensor whose initial life is assumed to be about 5 years may be extended by several years.
(2) Give the user many replacement timings.
It is because that was considered.

  The air conditioner AC of the present embodiment includes a refrigerant circuit 10 in which a refrigerant circulates, a refrigerant detection sensor 30 that detects leakage of the refrigerant, and a control unit 60 that controls the refrigerant circuit. Then, when the first period T1 has elapsed and the refrigerant detection sensor 30 needs to be replaced, the control unit 60 notifies the air conditioning control terminal 22 when the second period T2 shorter than the first period T1 has elapsed. It is possible to make a notification, detect an abnormality of the refrigerant detection sensor 30 after the first period T1 has elapsed, and forcibly stop the air-conditioning operation when the predetermined period Tc has elapsed.

  The advance notification is a notification that the air conditioning operation cannot be performed. In addition, the advance notification is a notification that the refrigerant detection sensor 30 needs to be replaced. The advance notification is displayed on the display unit of the air conditioning control terminal 22 of the air conditioner AC, and is reported, the light emitting unit of the air conditioning control terminal 22 is reported by light emission, and the voice of the air conditioning control terminal 22 is reported by voice. At least one.

  The control unit 60 can cause the air-conditioning control terminal 22 to notify that the refrigerant detection sensor 30 needs to be replaced when the first period T1 has elapsed. Further, after the first period T1 has elapsed, the control unit 60 may be in a state where the air conditioning operation cannot be performed after a second predetermined period Tc2 longer than the predetermined period Tc.

  The control unit 60 detects an abnormality of the refrigerant detection sensor 30 after the first period T1 has elapsed, and can disable the air conditioning operation when the predetermined period Tc has elapsed. When the refrigerant detection sensor abnormality / failure monitoring unit 65 detects the sensor abnormality or the sensor failure before the first period T1 has elapsed, the notification unit 66 notifies the sensor abnormality via the air conditioning control terminal 22 that the sensor abnormality is present. Alternatively, it notifies that there is a sensor failure. In the case of a sensor abnormality, the air conditioning operation may not be immediately stopped, and the user may wait for the sensor to be replaced. In the case of a sensor failure, it is preferable to make the air conditioning operation impossible immediately.

  FIG. 9 is a flowchart showing the life management process of the refrigerant detection sensor. Referring to FIG. 7 as appropriate. The refrigerant detection sensor life management unit 63 executes a life management process of the refrigerant detection sensor 30. When the air conditioning operation starts (step S601), the refrigerant detection sensor life management unit 63 causes the operation time accumulation unit 64 to accumulate the operation time. In the present embodiment, a circuit voltage is supplied to the refrigerant detection sensor 30 during the air-conditioning operation. When the refrigerant detection sensor 30 is energized when the air conditioning is stopped, the operation time may be accumulated by the operation time accumulation unit 64. This is for improving the accuracy of the life management of the refrigerant detection sensor 30.

  The refrigerant detection sensor life management unit 63 determines whether the second period T2 has elapsed (step S602). If the second period T2 has elapsed (step S602, Yes), the process proceeds to step S603, where the second period T2 is determined. If T2 has not elapsed (step S602, No), the process returns to step S602.

  In step S603, the notification unit 66 displays an advance notice on the display of the air conditioning control terminal 22. The notice display includes, for example, "The refrigerant sensor replacement time is approaching. The contact address is xxxx." Then, the process proceeds to step S604.

  The refrigerant detection sensor life management unit 63 determines whether or not the sensor has been replaced (step S604). If the sensor has not been replaced (step S604, incomplete), the process proceeds to step S605, and the sensor has been replaced. (Step S604, completion), the integration time is initialized (for example, integration time = 0) (Step S620), and the process returns to Step S602.

  In step S605, the refrigerant detection sensor life management unit 63 determines whether or not the first period T1 has elapsed. If the first period T1 has elapsed (step S605, Yes), the process proceeds to step S606, where the first period T1 is determined. If T1 has not elapsed (step S605, No), the process returns to step S604.

  In step S606, the notification unit 66 displays the first life notification on the display of the air conditioning control terminal 22. The first life notification includes, for example, "It is time to replace the refrigerant detection sensor. The contact address is xxxx." Then, the process proceeds to step S607.

  The refrigerant detection sensor life management unit 63 determines whether the sensor has been replaced (step S607). If the sensor has not been replaced (step S607, incomplete), the process proceeds to step S608, and the sensor has been replaced. (Step S607, completion), the integration time is initialized (for example, integration time = 0) (Step S620), and the process returns to Step S602.

  In step S608, the refrigerant detection sensor life management unit 63 determines whether a sensor abnormality has been detected. If a sensor abnormality has been detected (Yes in step S608), the process proceeds to step S609, and the sensor abnormality detection is performed. If not (step S608, No), the process returns to step S607.

  In step S609, the notification unit 66 displays the second life notification on the display of the air conditioning control terminal 22. The second life notification includes, for example, "There is an abnormality in the refrigerant detection sensor, and it should be replaced immediately. The contact address is xxxx." Then, the process proceeds to step S610.

  The refrigerant detection sensor life management unit 63 determines whether or not the sensor has been replaced (step S10). If the sensor has not been replaced (step S610, incomplete), the process proceeds to step S611, and if the sensor has been replaced. (Step S610, completion), the integration time is initialized (for example, integration time = 0) (Step S620), and the process returns to Step S602.

In step S611, the refrigerant detection sensor life management unit 63 determines whether the predetermined period Tc has elapsed. If the predetermined period Tc has not elapsed (step S611, No), the process returns to step S610. On the other hand, when the predetermined period Tc has elapsed (Step S611, Yes), the refrigerant detection sensor life management unit 63 forcibly stops the operation of the air conditioner AC to disable the operation (Step S612), and the notification unit 66 Then, the operation disable notification is displayed on the display of the air conditioning control terminal 22 (step S613). The non-operation notification includes, for example, "There is an error in the refrigerant detection sensor. Operation cannot be performed until the sensor is replaced."
The above is the life management process of the refrigerant detection sensor.

FIG. 10 is a diagram illustrating an example of an abnormality determination value of the refrigerant detection sensor. Reference is made to FIGS. 7 and 9 as appropriate. The horizontal axis is the gas concentration, and the vertical axis is the output voltage Vout from the refrigerant detection sensor 30. The voltage Vc is a circuit voltage of the refrigerant detection sensor 30. Normally, refrigerant leakage determination unit 62, the output voltage Vout is the voltage V ₃ or more, and, if the voltage V ₄ or less, it is determined that the "refrigerant leakage".

For the sensor abnormality detection in step S608 of FIG. 9, the refrigerant detection sensor abnormality / failure monitor section 65, the output voltage Vout is lower than the voltage V _2, or, when it exceeds the voltage V _5, the abnormality of the refrigerant detection sensor 30 It is determined that there is. Further, it is determined that the refrigerant detection sensor abnormality / failure monitor section 65 is less than the output voltage Vout is the voltage V _1, or, if it exceeds voltage V _6, is a failure of the coolant sensor 30. This takes into account the instability of the output voltage Vout when the refrigerant detection sensor 30 exceeds the expected life.

That is, the upper limit (for example, the voltage V ₅ ) and the lower limit (for example, the voltage V ₂ ) for determining the abnormality of the refrigerant detection sensor 30 are determined for the output voltage of the refrigerant detection sensor 30. It may be determined that the refrigerant detection sensor is abnormal when the output voltage Vout exceeds the upper limit value or when the output voltage Vout is lower than the lower limit value.

  As described above, in the embodiment, the configuration in which the indoor unit 100 (see FIG. 3) is a floor-standing type has been described, but the present invention is not limited to this. That is, the indoor unit 100 may be a ceiling embedded type or a wall mounted type.

  Further, the refrigerant detection sensor 30 may be provided outside the indoor unit 100. For example, in a configuration in which the indoor unit 100 embedded in the ceiling is provided, a configuration may be employed in which the refrigerant detection sensor 30 is installed near a floor where the leaked refrigerant is likely to settle and accumulate (near a floor in a space to be air-conditioned). .

  Further, in the embodiment, the configuration in which the air conditioner AC (see FIG. 1) includes one indoor unit 100 has been described, but the configuration is not limited to this. That is, each embodiment can be applied to a building multi air conditioner (Variable Refrigerant Flow: VRF) or a packaged air conditioner (Packaged Air Conditioning systems: PAC) having a plurality of indoor units. In addition, each embodiment can be applied to an integrated air conditioner in which an indoor unit and an outdoor unit are integrated.

  In addition, each embodiment is described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to one having all the described configurations. Further, for a part of the configuration of each embodiment, it is possible to add, delete, or replace another configuration. In addition, the above-described mechanisms and configurations are shown to be necessary for the description, and do not necessarily indicate all the mechanisms and configurations on the product.

Reference Signs List 10 refrigerant circuit 11 compressor 12 four-way valve 13 outdoor heat exchanger (condenser / evaporator)
14 Expansion valve 15 Indoor heat exchanger (evaporator / condenser)
21 cabinet 22 air conditioning control terminal (remote control)
Reference Signs List 30 refrigerant detection sensor 30a sensor part 30b sensor substrate 31 sensor case 31a base part 31b side wall 31c slit (refrigerant intake)
50, 60 control unit 44 electrical box 100 indoor unit 200 outdoor unit AC air conditioner Fo outdoor fan Fi indoor fan T1 first period T2 second period T3 third period Tc predetermined period Tc2 second predetermined period

Claims (9)

A refrigerant circuit through which the refrigerant circulates,
A refrigerant detection sensor for detecting refrigerant leakage,
A control unit for controlling the refrigerant circuit,
Wherein the control unit, the first notification regarding the life of the refrigerant detection sensor when the shorter second period than in the first period for the life of the coolant sensor has elapsed,
When an abnormality of the refrigerant detection sensor is detected after the first period has elapsed, a second notification regarding the life of the refrigerant detection sensor is issued, and when a predetermined period has elapsed since the second notification , the air conditioning operation is performed. An air conditioner that makes it impossible . The air conditioner according to claim 1, wherein the first notification is a notification that air conditioning operation cannot be performed. The air conditioner according to claim 1, wherein the first notification is a notification that the refrigerant detection sensor needs to be replaced. Wherein, when said first period of time, the air conditioner according to claim 1, characterized in that the notification to the effect that there is a need for replacement of the refrigerant detection sensor. The air conditioner according to claim 1, wherein the control unit is configured to disable the air conditioning operation after a second predetermined period longer than the predetermined period after the first period has elapsed. The air according to claim 1, wherein the control unit detects an abnormality of the refrigerant detection sensor after the first period has elapsed, and disables the air-conditioning operation when the predetermined period has elapsed. Harmony machine. The air conditioner according to claim 1, wherein the refrigerant detection sensor is installed outside the air conditioner. The first notification is at least one of displaying and notifying on an air conditioning control terminal of the air conditioner, notifying by light emission of the air conditioning control terminal, and notifying by voice from the air conditioning control terminal. The air conditioner according to claim 1, characterized in that: For the output voltage of the refrigerant detection sensor, an upper limit value and a lower limit value for performing an abnormality determination are set, and the control unit determines that the output voltage exceeds the upper limit value, or that the output voltage is The air conditioner according to claim 1, wherein it is determined that the refrigerant detection sensor is abnormal when the value is smaller than the lower limit value.

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