Air conditioner

Abstract

To provide an air conditioner appropriately performing operation control using a dust sensor.SOLUTION: An air conditioner includes an indoor unit 20 having a dust sensor 26, and a control part for performing at least one of an internal cleaning operation of the indoor unit 20 and an air cleaning operation for cleaning air in an air-conditioned room provided with the indoor unit 20 based on a detection value of the dust sensor 26, and the control part performs the at least one based on a correction value having a value larger than a detection value of the dust sensor 26 when a use period of the dust sensor 26 is a predetermined period or more.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] With regard to an air conditioner equipped with a dust sensor that detects fine particles such as dust, for example, the technology described in Patent Document 1 is known. That is, Patent Document 1 describes that a sensitivity adjustment key is provided on the wireless remote control of the air conditioner, and the sensitivity of the dust sensor is adjusted based on the user's operation of the sensitivity adjustment key. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-65969 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, when a dust sensor is used for a long period of time, the dust sensor deteriorates and its detection sensitivity decreases. In the technology described in Patent Document 1, the user operates a sensitivity adjustment key on a wireless remote control, but the sensitivity is not always set to an appropriate level. It would be desirable to use a dust sensor to appropriately control the operation of an air conditioner, but Patent Document 1 does not describe such technology.

[0005] Therefore, an object of the present disclosure is to provide an air conditioner that uses a dust sensor to appropriately control operation. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the air conditioner of the present disclosure includes an indoor unit having a dust sensor, and a control unit that performs at least one of an internal cleaning operation of the indoor unit and an air purification operation that purifies the air in the air-conditioned room in which the indoor unit is installed based on the detection value of the dust sensor, and the control unit performs at least one of the above based on a correction value that is larger than the detection value of the dust sensor if the dust sensor has been in use for a predetermined period of time or longer. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide an air conditioner that uses a dust sensor to appropriately control operation. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a configuration diagram of an air conditioner according to an embodiment. [Figure 2] 1 is a vertical cross-sectional view of an indoor unit of an air conditioner according to an embodiment. [Figure 3] FIG. 2 is an explanatory diagram showing an example of the configuration of a dust sensor of the air conditioner according to the embodiment. [Figure 4] 4 is an explanatory diagram showing an example of a pulse signal in a photo IC of the dust sensor of the air conditioner according to the embodiment. FIG. [Figure 5] FIG. 2 is a functional block diagram of the air conditioner according to the embodiment. [Figure 6] 4 is an explanatory diagram showing the relationship between the duration of use of the dust sensor of the air conditioner according to the embodiment and the light intensity of the LED. FIG. [Figure 7] 10 is an explanatory diagram showing the relationship between the period of use of the dust sensor of the air conditioner according to the embodiment and the amount of increase from the detection value of the dust sensor to the corrected value. FIG. [Figure 8] FIG. 4 is an explanatory diagram showing the relationship between the detection value and the correction value of the dust sensor of the air conditioner according to the embodiment. [Figure 9] 4 is a flowchart showing processing by a control unit of the air conditioner according to the embodiment. [Figure 10]FIG. 10 is an explanatory diagram showing the relationship between the period of use of the dust sensor of the air conditioner according to the modified example and the amount of increase from the detected value of the dust sensor to the corrected value. DETAILED DESCRIPTION OF THE INVENTION

[0009] <Embodiment> <Air conditioner configuration> FIG. 1 is a configuration diagram of an air conditioner 100 according to an embodiment. The solid arrows in FIG. 1 indicate the flow of the refrigerant in the heating cycle. The dashed arrows in FIG. 1 indicate the flow of refrigerant in the cooling cycle. The air conditioner 100 is a device that performs air conditioning such as cooling and heating. As shown in Fig. 1, the air conditioner 100 includes components provided in the outdoor unit 30, such as a compressor 11, an outdoor heat exchanger 12, an outdoor fan 13, an expansion valve 14, and a four-way valve 17. The air conditioner 100 also includes components provided in the indoor unit 20, such as an indoor heat exchanger 15 and an indoor fan 16.

[0010] The compressor 11 is a device that compresses a low-temperature, low-pressure gas refrigerant and discharges it as a high-temperature, high-pressure gas refrigerant, and is equipped with a compressor motor 11a that serves as a drive source. Although not shown in Fig. 1, an accumulator for separating the refrigerant into gas and liquid is connected to the suction side of the compressor 11.

[0011] The outdoor heat exchanger 12 is a heat exchanger in which heat is exchanged between a refrigerant flowing through its heat transfer tubes (not shown) and outside air sent in from the outdoor fan 13. The outdoor fan 13 is a fan that sends outside air into the outdoor heat exchanger 12. The outdoor fan 13 is provided with an outdoor fan motor 13a as a drive source, and is installed near the outdoor heat exchanger 12.

[0012] The expansion valve 14 is a valve that reduces the pressure of the refrigerant condensed in the condenser (one of the outdoor heat exchanger 12 and the indoor heat exchanger 15). The refrigerant reduced in pressure by the expansion valve 14 is guided to the evaporator (the other of the outdoor heat exchanger 12 and the indoor heat exchanger 15).

[0013] The indoor heat exchanger 15 is a heat exchanger in which heat is exchanged between the refrigerant flowing through its heat transfer tubes 15b (see FIG. 2) and the indoor air (air in the air-conditioned room) sent from the indoor fan 16. The indoor fan 16 is a fan that sends the indoor air to the indoor heat exchanger 15. The indoor fan 16 is provided with an indoor fan motor 16a as a drive source, and is installed near the indoor heat exchanger 15.

[0014] The four-way valve 17 is a valve that switches the refrigerant flow path depending on the operation mode of the air conditioner 100. For example, during cooling operation (see the dashed arrow in FIG. 1), the refrigerant circulates in the refrigerant circuit 10 sequentially through the compressor 11, the outdoor heat exchanger 12 (condenser), the expansion valve 14, and the indoor heat exchanger 15 (evaporator). Also, during heating operation (see the solid arrow in FIG. 1), the refrigerant circulates in the refrigerant circuit 10 sequentially through the compressor 11, the indoor heat exchanger 15 (condenser), the expansion valve 14, and the outdoor heat exchanger 12 (evaporator).

[0015] FIG. 2 is a vertical cross-sectional view of the indoor unit 20. As shown in FIG. 2, in addition to the indoor heat exchanger 15 and the indoor fan 16, the indoor unit 20 includes a drain pan 18, a housing 19, filters 21a and 21b, and a front panel 22. The indoor unit 20 also includes left and right airflow direction vanes 23, up and down airflow direction vanes 24, air purification units 25A and 25B, and a dust sensor 26.

[0016] The indoor heat exchanger 15 includes a plurality of fins 15a and a plurality of heat transfer tubes 15b penetrating these fins 15a. The indoor fan 16 is, for example, a cylindrical crossflow fan, and is installed downstream of the indoor heat exchanger 15 in the air flow direction. In addition to the indoor fan motor 16a (see FIG. 1), the indoor fan 16 includes a plurality of fan blades 16b and an annular partition plate 16c on which these fan blades 16b are installed.

[0017] The drain pan 18 receives condensation water from the indoor heat exchanger 15 and is installed below the indoor heat exchanger 15. The housing 19 houses the indoor heat exchanger 15, the indoor fan 16, etc. The filters 21a and 21b collect dust from the air flowing toward the indoor heat exchanger 15, and are installed upstream of the indoor heat exchanger 15 in the air flow direction. More specifically, one filter 21a is installed in front of the indoor heat exchanger 15, and the other filter 21b is installed above the indoor heat exchanger 15.

[0018] Front panel 22 is a panel that is installed so as to cover front filter 21a. Front panel 22 may be configured to be fixed and not particularly rotatable. Alternatively, front panel 22 may be configured to be rotatable forward.

[0019] The horizontal airflow direction vane 23 is a plate-like member that adjusts the left-right direction of air blown out from the indoor unit 20. The horizontal airflow direction vane 23 is arranged in the blow-out air duct W1 of the indoor unit 20, and is configured to rotate left and right by a horizontal airflow direction vane motor 23a (see FIG. 5). The vertical airflow direction flap 24 is a plate-like member that adjusts the vertical direction of air blown out from the indoor unit 20. The vertical airflow direction flap 24 is disposed at the air outlet W2 of the indoor unit 20, and is configured to rotate vertically by a vertical airflow direction flap motor 24a (see FIG. 5).

[0020] The air drawn in through the filters 21a and 21b exchanges heat with the refrigerant flowing through the heat transfer tubes 15b of the indoor heat exchanger 15, and the heat-exchanged air is guided to the outlet airflow duct W1. The air flowing through the outlet airflow duct W1 is guided in a predetermined direction by the left-right airflow direction vanes 23 and the up-down airflow direction vanes 24, and is blown out into the air-conditioned room through the air outlet W2.

[0021] The air purifying units 25A and 25B are ionizers that generate predetermined ions. The ions generated by the air purifying units 25A and 25B charge particles in the air. The ions generated by the air purifying units 25A and 25B are OH- Ya O 2- The ions may be negative ions such as those mentioned above, or may be other types of ions.

[0022] In the example of Fig. 2, one air purification unit 25A is installed on the air intake side of the indoor unit 20. More specifically, the air purification unit 25A is installed between the front panel 22 and the front filter 21a. As shown in Fig. 2, the air purification unit 25A includes a plasma electrode 251A and a housing 252A.

[0023] Plasma electrode 251A is an electrode for generating predetermined ions by application of high voltage. Housing 252A is a container for accommodating plasma electrode 251A and the like. In the example of FIG. 2, in addition to plasma electrode 251A, dust sensor 26, which will be described later, is also accommodated in housing 252A. Furthermore, opening H1 is provided above air purification unit 25A in indoor unit 20. Predetermined ions are emitted from air purification unit 25A toward opening H1.

[0024] The other air purification unit 25B is installed on the air blowing side of the indoor unit 20. More specifically, the air purification unit 25B is installed in front of the drain pan 18 and above the air outlet W2. A predetermined opening H2 is provided below the air purification unit 25 in the indoor unit 20 (in the direction of ion emission). A high voltage is applied to a plasma electrode (not shown) to generate predetermined ions, which are then emitted from the air purification unit 25B through the opening H2 to the air outlet W2.

[0025] The air purification units 25A, 25B are driven appropriately in an interior cleaning operation or an air purification operation. Here, "interior cleaning operation" refers to an operation for purifying the inside of the indoor unit 20. Also, "air purification operation" refers to an operation for purifying the air in the air-conditioned room in which the indoor unit 20 is installed. The interior cleaning operation and air purification operation will be described later.

[0026] Dust sensor 26 shown in Fig. 2 is a sensor that detects fine particles in the air, and is provided on the air intake side of indoor unit 20. Examples of such fine particles include dust and mold floating in the air, as well as pollen and PM2.5. In the example of Fig. 2, dust sensor 26 is housed in housing 252A of air purification unit 25A, but dust sensor 26 may also be arranged on the outside of housing 252A.

[0027] For example, the dust sensor 26 may be configured to start being used when the "monitoring function" (a function for monitoring the degree of air pollution in an air-conditioned room) is switched on by the user operating the remote control 50 (see FIG. 5) or a mobile terminal (not shown). The dust sensor 26 may be configured to be constantly driven while the "monitoring function" is on. In this case, the dust sensor 26 continues to be driven not only while the air conditioning is running, but also while the air conditioning is stopped.

[0028] The detection value of the dust sensor 26 while air conditioning operation is being performed is used to estimate the degree of contamination (dust concentration) in the air-conditioned room. In addition, the detection value of the dust sensor 26 while air conditioning operation is stopped is used to estimate the degree of contamination (dust concentration) inside the indoor unit 20. It is also possible to temporarily stop use of the dust sensor 26 depending on the state of the air conditioner 100.

[0029] The following describes a case where the "light scattering method" is used as the detection method when detecting particulates with the dust sensor 26. Here, the "light scattering method" is a detection method in which light is irradiated into the air and the light scattered by the particulates is measured. However, other well-known detection methods such as the light transmission method and the triboelectric method can also be used as the detection method when detecting particulates.

[0030] FIG. 3 is an explanatory diagram showing an example of the configuration of the dust sensor 26. As shown in FIG. 3, dust sensor 26 includes case 261, heater 262, light-emitting unit 263, and light-receiving unit 264. Case 261 is a housing for housing heater 262, light-emitting unit 263, and light-receiving unit 264. Case 261 is provided with inlet 261a and outlet 261b as openings for allowing air to flow through the interior of case 261. Air that flows into case 261 through inlet 261a flows out through outlet 261b.

[0031] The heater 262 is an electric heater for generating heat. The heat from the heater 262 generates an ascending air current inside the case 261, and the air flows through the inlet 261a and the outlet 261b in this order.

[0032] The light-emitting unit 263 is a light source that emits a predetermined light (for example, infrared light). For example, an LED (Light Emitting Diode) is used as such a light-emitting unit 263. In the "light scattering method" described above, a portion of the light emitted from the light-emitting unit 263 is scattered by fine particles in the air, and the scattered light is incident on the light-receiving unit 264. It is assumed that light (infrared light) continues to be emitted from the light-emitting unit 263 while the dust sensor 26 is in use.

[0033] The light receiving unit 264 receives scattered light resulting from scattering of light by the particles and converts the received light into a predetermined electrical signal. As shown in Fig. 3, the light receiving unit 264 includes a lens 264a and a photo IC (Integrated Circuit) 264b. The lens 264a is an optical element that refracts light incident thereon and focuses it onto the photo IC 264b.

[0034] The photo IC 264b is an integrated circuit for photoelectrically converting light incident through the lens 264a, and is configured to emit a predetermined pulse signal according to the amount of light received. Although not shown, the photo IC 264b is configured to include a photoelectric conversion element such as a photodiode or phototransistor, and a signal processing circuit.

[0035] FIG. 4 is an explanatory diagram showing an example of a pulse signal in the photo IC of the dust sensor (also see FIG. 3 as appropriate). 4, the horizontal axis represents time, and the vertical axis represents the pulse signal from the photo IC 264b of the dust sensor 26. It is assumed that while the dust sensor 26 is in use, a predetermined pulse signal continues to be output from the photo IC 264b.

[0036] For example, when the concentration of particles in the air (dust concentration) is low, almost no light scattered by the particles (light irradiated from the light-emitting unit 263 and scattered by the particles) enters the light-receiving unit 264. In such a case, the photo IC 264b is set so that the value of the pulse signal becomes "High." Furthermore, when light scattered by the particles enters the light-receiving unit 264, the pulse signal of the photo IC 264b switches from "High" to "Low." Note that the higher the concentration of particles in the air (dust concentration), the more easily light scattered by the particles enters the light-receiving unit 264, and therefore the longer the time the pulse signal remains low.

[0037] Therefore, the predetermined time t P For the pulse signal, the low time t α ,t β ,t γ The sum of (t α +t β +t γ ) is used as the detection value of the dust sensor 26. In other words, the detection value of the dust sensor 26 is the low time ratio in the pulse signal. This low time ratio may be calculated by the control unit 40 (see FIG. 5) described later, or may be calculated inside the dust sensor 26.

[0038] FIG. 5 is a functional block diagram of the air conditioner 100. The indoor unit 20 shown in FIG. 5 includes a remote control transmitting / receiving unit 27, an indoor temperature sensor 28, and an indoor control circuit 41 in addition to the components described above. The remote control transmitter / receiver 27 exchanges predetermined information with the remote control 50 by infrared communication or the like. The indoor temperature sensor 28 is a sensor that detects the temperature of the air-conditioned room, and is installed, for example, on the air intake side of the indoor heat exchanger 15.

[0039] Although not shown, the indoor control circuit 41 is configured to include electronic circuits such as a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), various interfaces, etc. The program stored in the ROM is read and expanded in the RAM, and the CPU executes various processes.

[0040] 5, the indoor control circuit 41 includes a memory unit 41a and an indoor control unit 41b. The memory unit 41a stores predetermined programs, as well as data received via the remote control transceiver unit 27 and detection values ​​of each sensor. The indoor control unit 41b controls the indoor fan motor 16a, the left / right airflow direction vane motor 23a, the up / down airflow direction vane motor 24a, and the air purification units 25A and 25B in a predetermined manner based on signals received from the remote control 50 and detection values ​​of the indoor temperature sensor 28 and the dust sensor 26.

[0041] In addition to the components described above, the outdoor unit 30 is equipped with an outdoor temperature sensor 31 and an outdoor control circuit 42. The outdoor temperature sensor 31 is a sensor that detects the temperature of outside air, and is installed at a predetermined location in the outdoor unit 30. The detected values ​​of the outdoor temperature sensor 31, etc. are output to the outdoor control circuit 42.

[0042] Although not shown, the outdoor control circuit 42 is configured to include electronic circuits such as a CPU, ROM, RAM, and various interfaces, and is connected to the indoor control circuit 41 via a communication line. As shown in Fig. 5, the outdoor control circuit 42 is equipped with a memory unit 42a and an outdoor control unit 42b. The memory unit 42a has predetermined programs stored in advance, as well as the detected value of the outdoor temperature sensor 31 and data received from the indoor control circuit 41. The outdoor control unit 42b controls the compressor motor 11a, the outdoor fan motor 13a, the expansion valve 14, and the four-way valve 17 based on the data in the memory unit 42a.

[0043] Hereinafter, the indoor control circuit 41 and the outdoor control circuit 42 are collectively referred to as the control unit 40. The control unit 40 appropriately drives the air purification units 25A and 25B based on the detection value of the dust sensor 26 to perform the above-mentioned interior cleaning operation and air purification operation.

[0044] <About dust sensor deterioration> FIG. 6 is an explanatory diagram showing the relationship between the period of use of the dust sensor and the light intensity of the LED (also see FIG. 3 as appropriate). 6, the horizontal axis represents the usage period of dust sensor 26, and the vertical axis represents the light intensity of the LED used as light-emitting unit 263 of dust sensor 26. Here, the usage period of dust sensor 26 is the integrated value (value obtained by sequentially adding up) of the time during which light (e.g., infrared light) is irradiated from light-emitting unit 263.

[0045] It is desirable that the amount of light emitted from the LED (light emitting unit 263) of the dust sensor 26 be constant regardless of the length of time the dust sensor 26 has been in use. However, in reality, the longer the period of use of the dust sensor 26, the more the LED deteriorates over time, and the amount of light gradually decreases. In the example of FIG. 6, the period of use is a predetermined period t L The light intensity of the LED is approximately the same as when it was new until the (first period) is reached, but after a predetermined period t L After this time, the LED light intensity gradually decreases.

[0046] When the light intensity of the LED decreases in this way, the Low time ratio in the pulse signal of the photo IC 264b (see FIG. 4) described above becomes lower than the intended value, and as a result, the detection value of the dust sensor 26 becomes lower than the intended value. In other words, the detection sensitivity of the dust sensor 26 decreases. Therefore, in this embodiment, when the period of use of the dust sensor 26 reaches a predetermined period, the control unit 40 (see FIG. 5) corrects the detection value of the dust sensor 26. As an example, a case will be described below in which the control unit 40 adds a predetermined value corresponding to the length of time the dust sensor 26 has been in use to the detection value of the dust sensor 26.

[0047] FIG. 7 is an explanatory diagram showing the relationship between the period of use of the dust sensor and the amount of increase from the detected value of the dust sensor to the corrected value (see also FIG. 3 as appropriate). 7, the horizontal axis represents the period of use of the dust sensor 26, and the vertical axis represents the amount of increase from the detected value of the dust sensor 26 to the corrected value. As shown in FIG. 7, when the period of use of the dust sensor 26 is a predetermined period t L , the increase in the detection value of the dust sensor 26 is zero. In this case, the light intensity of the LED (light emitting portion 263) of the dust sensor 26 hardly decreases (see FIG. 6), and there is no particular need to correct the detection value. In other words, if the period of use of the dust sensor 26 is longer than the predetermined period t L Until this value is reached, the detection value of the dust sensor 26 is directly reflected in the operation control of the air conditioner 100 (see FIG. 5).

[0048] On the other hand, if the period of use of the dust sensor 26 is a predetermined period t L After the predetermined period t is reached, the increase from the detection value of the dust sensor 26 to the correction value increases linearly. In other words, the longer the period of use of the dust sensor 26, the larger the increase from the detection value to the correction value. For example, L A specified period of use t that is longer than A is a predetermined increment Δσ A In addition, the usage period t A A specified period of use t that is longer than B The aforementioned increase Δσ AAnother increment Δσ that is larger than B are associated.

[0049] The rate at which the correction value is increased relative to the length of the usage period is set in advance based on the average rate at which the LED light intensity decreases (see FIG. 6) and the specifications of the photo IC 264b (see FIG. 3). Data (such as that shown in FIG. 7) that associates the usage period of the dust sensor 26 with the amount of increase from the detection value of the dust sensor 26 to the correction value is stored in advance as a predetermined formula or data table.

[0050] FIG. 8 is an explanatory diagram showing the relationship between the detection value of the dust sensor and the correction value (also see FIG. 3 as appropriate). 8, the horizontal axis represents the detection value of the dust sensor 26, and the vertical axis represents the correction value of the dust sensor 26. In other words, the correction value shown in FIG. 8 is the value obtained by adding the increase amount explained in FIG. 7 to the detection value. The dashed line L0 in FIG. 8 represents the time when the dust sensor 26 has been in use for a predetermined period t L 7. It should be noted that the straight line shows the relationship between the detection value and the correction value when the period of use of the dust sensor 26 is shorter than the predetermined period t L If the distance is shorter than 100 msec, no correction of the detected value is performed, but for convenience, FIG. 8 shows a straight line L0 (a straight line passing through the origin with a slope of 1).

[0051] The dashed line in Figure 8 is the straight line L A is the time period t A This is a straight line that shows the relationship between the detection value and the correction value when only the IR filter (see Figure 7) is used. A is a predetermined increment Δσ A (See also FIG. 7) For example, the detection value α0 of the dust sensor 26 is added with an increase Δσ A is added to calculate the correction value σ1.

[0052] In addition, the solid line L in Fig. 8 B is the time period t BThis is a straight line that shows the relationship between the detection value and the correction value when only the IR filter (see Figure 7) is used. B is the increment Δσ of the value of each point on the line L0. B (See also FIG. 7) For example, the detection value α0 of the dust sensor 26 is added with an increase Δσ B In this way, a predetermined value (for example, the increase amount Δσ) corresponding to the period of use of the dust sensor 26 is added to the correction value σ2. A and the increase Δσ B ) is added to the detected value.

[0053] The method for correcting the detection value of the dust sensor 26 is not limited to adding a predetermined value to the detection value. For example, if the period of use of the dust sensor 26 is longer than a predetermined period t L (see FIG. 6), the control unit 40 may multiply the detection value of the dust sensor 26 by a predetermined value (a value greater than 1). In this case, the longer the period of use of the dust sensor 26, the larger the predetermined value.

[0054] In addition, the period of use of the dust sensor 26 is a predetermined period t L (See FIG. 6) has passed, the control unit 40 may generate a correction value (a value larger than the detection value) by substituting the detection value of the dust sensor 26 into a predetermined formula or by reading a value corresponding to the detection value from a predetermined data table. The formula and data table are set so that the longer the period of use of the dust sensor 26, the greater the increase from the detection value to the correction value.

[0055] <Processing of control section> FIG. 9 is a flowchart showing the processing of the control unit (also see FIG. 5 as appropriate). At the time of "START" in FIG. 9, air conditioning operation such as cooling operation or heating operation may be in progress, or air conditioning operation may be stopped. In step S101, the control unit 40 reads the detection value of the dust sensor . In step S102, the control unit 40 determines whether the period of use of the dust sensor 26 is equal to or longer than a predetermined period.

[0056] The predetermined period is a threshold value that serves as a criterion for determining whether or not to correct the detection value of the dust sensor 26, and is set in advance. This predetermined period is a first period (predetermined period t in FIG. 6) from the start of use of the dust sensor 26 (the start of light irradiation by the LED, which is the light-emitting unit 263) until the amount of light from the LED starts to decrease. L ) and may be a period longer than the first period.

[0057] If it is determined in step S102 that the period of use of the dust sensor 26 is equal to or longer than the predetermined period (S102: Yes), the process of the control unit 40 proceeds to step S103. In step S103, the control unit 40 corrects the detection value of the dust sensor 26. That is, the control unit 40 calculates a correction value that is a value greater than the detection value of the dust sensor 26. As described above, there are various methods for calculating the correction value, but the correction value is set so that the longer the period of use of the dust sensor 26, the greater the increase from the detection value to the correction value.

[0058] In step S104, the control unit 40 determines whether the correction value is equal to or greater than a predetermined value. The predetermined value is a threshold value that serves as a criterion for determining whether or not the detection value of the dust sensor 26 is reflected in the internal cleaning operation or the air purification operation, and is set in advance as an appropriate value. If the correction value of the dust sensor 26 is equal to or greater than the predetermined value in step S104 (S104: Yes), the processing of the control unit 40 proceeds to step S105.

[0059] In step S105, the control unit 40 reflects the correction value of the dust sensor 26 in the internal cleaning operation and the air purification operation. That is, the control unit 40 performs the internal cleaning operation and the air purification operation in a mode when the dust concentration in the air-conditioned room is high (the correction value of the dust sensor 26 is equal to or greater than a predetermined value). Details of the processing of step S105 will be described later. After performing the processing of step S105, the processing of the control unit 40 returns to "START" (RETURN).

[0060] In this way, if the period of use of the dust sensor 26 is equal to or longer than the predetermined period (S102: Yes), the control unit 40 performs the interior cleaning operation or the air purification operation based on the correction value that is greater than the detection value of the dust sensor 26 (S105).

[0061] Furthermore, if the correction value of the dust sensor 26 is less than the predetermined value in step S104 (S104: No), the process of the control unit 40 returns to "START" (RETURN). In this case, although not specifically shown in Fig. 9, the interior cleaning operation and air purification operation are appropriately performed in a mode when the dust concentration in the air-conditioned room is not so high.

[0062] Furthermore, if it is determined in step S102 that the period of use of dust sensor 26 is less than the predetermined period (S102: No), the process of control unit 40 proceeds to step S106. In this case, the LED that is light-emitting unit 263 of dust sensor 26 is in a state where it has hardly deteriorated, so there is no particular need to correct the detection value of dust sensor 26.

[0063] In step S106, the control unit 40 determines whether the detection value of the dust sensor 26 is equal to or greater than a predetermined value. Note that the "predetermined value" in step S106 (when the detection value is used as is) and the "predetermined value" in step S104 (when a corrected value is used) may be the same value. If the detection value of the dust sensor 26 is equal to or greater than the predetermined value in step S106 (S106: Yes), the control unit 40 proceeds to step S105.

[0064] In step S105, the control unit 40 reflects the detection value of the dust sensor 26 in the internal cleaning operation and the air purification operation. Also, if the detection value of the dust sensor 26 is less than the predetermined value in step S106 (S106: No), the processing of the control unit 40 returns to "START" (RETURN). Next, the interior cleaning operation and the air cleaning operation will be described in order with reference to FIG.

[0065] <Internal cleaning operation> As described above, the "internal cleaning operation" is an operation for cleaning the inside of the indoor unit 20. Examples of such internal cleaning operations include an operation for driving the air purification unit 25B on the air blowing side, an operation for cleaning the indoor heat exchanger 15, an operation for cleaning the fan, and an operation for drying the inside of the indoor unit 20. The control unit 40 (see FIG. 5) executes at least one of the above-mentioned multiple operation modes as the internal cleaning operation. Note that the internal cleaning operation may be performed when the accumulated operating time of the air conditioner 100 reaches a predetermined value, or the internal cleaning operation may be performed periodically, such as once per day.

[0066] First, a case where air purification unit 25B on the air blowing side is driven for the internal cleaning operation will be described. Note that air purification unit 25A on the air suction side may be kept stopped during the internal cleaning operation. For example, control unit 40 (see FIG. 5) rotates indoor fan 16 in the reverse direction (opposite to the direction of rotation during normal air conditioning operation) with up / down air direction vanes 24 closed, and applies a high voltage to the plasma electrode (not shown) of air purification unit 25B.

[0067] As a result, ions generated by the air purification unit 25B fill the interior of the indoor unit 20 and attach to and charge fine particles in the air, such as dust, mold, and PM2.5. The charged fine particles move inside the indoor unit 20 as the indoor fan 16 is driven, and attach to the indoor heat exchanger 15. The fine particles attached to the indoor heat exchanger 15 are washed away in the subsequent cleaning operation.

[0068] The "cleaning operation," which is one of the internal cleaning operations, is an operation in which the indoor heat exchanger 15 is cooled to below freezing point to cause frost (or condensation), and then the temperature of the indoor heat exchanger 15 is raised to thaw it, thereby washing away dust and other particles from the indoor heat exchanger 15.

[0069] Furthermore, the "fan cleaning operation," which is one of the internal cleaning operations, is an operation in which the indoor fan 16 is cleaned by a fan cleaning unit (not shown). For example, the control unit 40 may drive the indoor fan 16 while the brush of the fan cleaning unit is in contact with the indoor fan 16. This allows the brush to remove dust adhering to the indoor fan 16, keeping the indoor fan 16 clean.

[0070] Furthermore, the "drying operation," which is one of the interior cleaning operations, is an operation in which the indoor fan 16 is driven with the vertical airflow direction flap 24 open to dry the inside of the indoor unit 20. Note that, during at least a portion of the drying operation, the control unit 40 may cause the indoor heat exchanger 15 to function as a condenser and raise the temperature of the indoor heat exchanger 15. This promotes drying of the inside of the indoor unit 20, thereby suppressing the growth of mold.

[0071] For example, if the period of use of the dust sensor 26 is equal to or longer than a predetermined period (S102: Yes in FIG. 9), and the correction value of the dust sensor 26 is equal to or greater than a predetermined value (S104: Yes), the control unit 40 increases the frequency of the interior cleaning operation (S105). This makes it possible to keep the interior of the indoor unit 20 clean even when a large amount of fine particles such as dust are present.

[0072] <Air purification operation> As described above, "air purification operation" is an operation for purifying the air in the air-conditioned room in which the indoor unit 20 is installed. Note that the air purification operation may be switched between ON and OFF based on the user's operation of the remote control 50 (see FIG. 5) or mobile terminal. The control unit 40 appropriately drives the air purification units 25A and 25B during the period when the air purification operation is set to ON to perform the air purification operation.

[0073] In the air purification operation, the control unit 40 drives the indoor fan 16 with the upper and lower louvers 24 open. The air purification operation may be performed during air conditioning operation, or may be performed while the air conditioning operation is stopped. When generating predetermined ions when the detection value of the dust sensor 26 (or the corrected value if the detection value is corrected) is less than a predetermined value, the control unit 40, for example, drives the air purification unit 25B on the air blowing side while keeping the air purification unit 25A on the air suction side stopped.

[0074] The ions generated by the air purification unit 25B are blown into the air-conditioned room and attach to and charge fine particles in the air, such as dust, mold, and PM2.5. The charged fine particles move through the air intake of the indoor unit 20, some of which are captured by the filters 21a and 21b, while the rest pass through the tiny gaps between the filters 21a and 21b and attach to the indoor heat exchanger 15. The fine particles captured by the filters 21a and 21b are removed during filter cleaning operation. Dust adhering to the indoor heat exchanger 15 is washed away during the cleaning operation described above.

[0075] For example, if dust sensor 26 has been in use for a predetermined period of time or longer (S102: Yes in FIG. 9), and if the correction value of dust sensor 26 is equal to or greater than a predetermined value (S104: Yes), control unit 40 increases the number of air purification units being driven for air purification operation (S105). Specifically, control unit 40 increases the number of air purification units being driven from one (air purification unit 25B) to two, and drives air purification unit 25B on the air blowing side while also driving air purification unit 25A on the air suction side. By driving both air purification units 25A and 25B in this way, the air in the air-conditioned room can be kept clean even when there is a large amount of fine particles such as dust in the air.

[0076] According to this embodiment, when the period of use of dust sensor 26 reaches a predetermined period, control unit 40 performs the internal cleaning operation or the air purification operation based on a correction value that is greater than the detection value of dust sensor 26. As a result, even if the light intensity of light-emitting element 263 of dust sensor 26 has decreased, the internal cleaning operation or the air purification operation can be performed in the same way as when dust sensor 26 is new.

[0077] Furthermore, according to this embodiment, it is possible to reduce costs for the user because there is no need to replace the dust sensor 26 even if the dust sensor 26 deteriorates over time. Furthermore, when correcting the detection value of the dust sensor 26, the user does not need to operate the remote control 50 or a mobile terminal, which saves the user time and effort.

[0078] Furthermore, according to this embodiment, the longer the period of use of the dust sensor 26, the greater the increase in the correction value from the detection value of the dust sensor 26. This makes it possible to correct the detection value of the dust sensor 26 to an appropriate value depending on the period of use of the dust sensor 26.

[0079] <<Variations>> The air conditioner 100 according to the present disclosure has been described above in various embodiments, but is not limited to these descriptions and various modifications can be made. For example, in the embodiments, the case where the increase from the detected value to the corrected value continuously increases as the period of use of the dust sensor 26 increases (see FIG. 7) has been described, but the present disclosure is not limited to this and may be made as follows.

[0080] FIG. 10 is an explanatory diagram showing the relationship between the period of use of the dust sensor of the air conditioner according to the modified example and the amount of increase from the detected value of the dust sensor to the corrected value. 10, the horizontal axis represents the period of use of the dust sensor 26, and the vertical axis represents the amount of increase from the detection value of the dust sensor 26 to the corrected value. In the example of FIG. 10, the period of use of the dust sensor 26 is a predetermined period t LAfter reaching this value, the longer the period of use, the larger the amount of increase from the detection value to the correction value. Even in such a case, the longer the period of use of the dust sensor 26, the larger the amount of increase from the detection value to the correction value.

[0081] Furthermore, in the embodiment, a case where the internal cleaning operation and the air purification operation are each performed appropriately has been described, but this is not limiting. That is, the embodiment can also be applied to a case where the internal cleaning operation is performed while the air purification operation is not performed. Furthermore, the embodiment can also be applied to a case where the air purification operation is performed while the internal cleaning operation is not performed. That is, the embodiment can also be applied to a case where the control unit 40 performs at least one of the internal cleaning operation of the indoor unit 20 and the air purification operation that purifies the air in the air-conditioned room in which the indoor unit 20 is installed based on the detection value of the dust sensor 26. Furthermore, if the dust sensor 26 has been in use for a predetermined period of time or longer, the control unit 40 performs at least one of the internal cleaning operation and the air purification operation based on a correction value that is greater than the detection value of the dust sensor 26. Even with this type of processing, the same effects as those of the embodiment can be achieved.

[0082] In the embodiment, the “predetermined period” (threshold value of the period of use of the dust sensor 26) that serves as the criterion for determining whether or not to correct the detection value of the dust sensor 26 is the “first period” (predetermined period t in FIG. 6 ) until the light intensity of the light emitting unit 263 (LED) of the dust sensor 26 starts to decrease. L ) is used in the above description, but the present invention is not limited to this. That is, a period longer than the above-mentioned "first period" may be used as the "predetermined period" that serves as the criterion for determining whether or not to correct the detection value of the dust sensor 26.

[0083] In the embodiment, the air purification units 25A, 25B generate predetermined ions to charge dust drawn into the indoor unit 20, but this is not limiting. For example, a predetermined air purification unit may generate ozone (O3). In this case, the control unit 40 drives the indoor fan 16 with the upper and lower airflow direction flap 24 closed to fill the interior of the indoor unit 20 with ozone. This allows the interior of the indoor unit 20 to be disinfected.

[0084] Furthermore, in the embodiment, a case has been described in which air purifying unit 25A is installed on the air intake side of indoor unit 20 and another air purifying unit 25B is installed on the air outlet side of indoor unit 20, but this is not limiting. That is, the embodiment can also be applied to a configuration in which one or both of air purifying units 25A and 25B are omitted. For example, if both air purifying units 25A and 25B are omitted, the above-mentioned washing operation, fan cleaning operation, and drying operation are performed as appropriate as the internal cleaning operation based on the detection value (or corrected value) of dust sensor 26. Furthermore, three or more air purifying units may be installed in indoor unit 20. In this case, the same effects as those of the embodiment can be achieved.

[0085] Furthermore, in the embodiment, a configuration has been described in which the air conditioner 100 (see FIG. 1) is provided with the four-way valve 17, but this is not limiting. That is, the four-way valve 17 may be omitted from the air conditioner 100, and the air conditioner may be configured to be dedicated to cooling or heating. In the embodiment, a configuration in which one indoor unit 20 (see FIG. 1) and one outdoor unit 30 (see FIG. 1) are provided has been described, but the configuration is not limited to this. That is, a plurality of indoor units connected in parallel may be provided, and a plurality of outdoor units connected in parallel may also be provided. Furthermore, in the embodiment, a case has been described in which the air conditioner 100 is a room air conditioner, but the embodiment can also be applied to various types of air conditioners, such as packaged air conditioners and multi-air conditioners for buildings.

[0086] Furthermore, the embodiments have been described in detail to clearly explain the present disclosure, and are not necessarily limited to those including all of the configurations described. Furthermore, some of the configurations of the embodiments may be added to, deleted from, or replaced with other configurations. Furthermore, the mechanisms and configurations described above are those that are considered necessary for the explanation, and do not necessarily represent all mechanisms and configurations of the product. [Explanation of symbols]

[0087] 10 Refrigerant circuit 11 Compressor 12 Outdoor heat exchanger 13 Outdoor fan 14 Expansion valve 15 Indoor heat exchanger 16 Indoor fan 17 Four-way valve 20 Indoor unit 25A, 25B Air Purification Unit 26 Dust sensor 30 Outdoor unit 40 Control Unit 50 Remote Control 100 Air conditioner 261 cases 262 Heater 263 Light-emitting part (LED) 264 Light receiving part 264a lens 264b Photo IC

Claims

1. The indoor unit has a dust sensor, a control unit that performs at least one of an internal cleaning operation of the indoor unit and an air cleaning operation that purifies the air in an air-conditioned room in which the indoor unit is installed based on a detection value of the dust sensor; The control unit performs at least one of the above operations based on a correction value that is greater than the detection value of the dust sensor when the period of use of the dust sensor is equal to or greater than a predetermined period.

2. The dust sensor has a light emitting unit and a light receiving unit, the light-emitting unit is an LED (Light Emitting Diode), The predetermined period is a first period from when the dust sensor is first used until the amount of light from the LED begins to decrease, or is a period longer than the first period.

2. The air conditioner according to claim 1,

3. the light receiving unit has a lens and a photo IC (Integrated Circuit) that emits a pulse signal according to the amount of received light, The detected value is a Low time ratio in the pulse signal.

3. The air conditioner according to claim 2, wherein:

4. The longer the period of use of the dust sensor, the greater the increase in the correction value from the detection value.

2. The air conditioner according to claim 1,

5. The control unit increases the frequency of the internal cleaning operation when the correction value is equal to or greater than a predetermined value in a case where the period of use of the dust sensor is equal to or greater than the predetermined period.

2. The air conditioner according to claim 1,

6. When the period of use of the dust sensor is equal to or longer than the predetermined period and the correction value is equal to or greater than a predetermined value, the control unit increases the number of air cleaning units to be driven for the air cleaning operation.

2. The air conditioner according to claim 1,

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