Air conditioners

Abstract

To provide an air conditioner that efficiently operates to clean an indoor heat exchanger.SOLUTION: Before a stop duration (T2), which is started to measure from the stop timing of air-conditioning operation or dehumidifying operation, exceeds a pre-set reference time (m1), if a controller (40) executes air-conditioning operation for the purpose of cleaning, heating operation or air-blowing operation is executed to return the moisture deposited on an indoor heat exchanger (32) to the indoor side before executing the air-conditioning operation for cleaning.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an air conditioner equipped with a cleaning operation function for cleaning the surface of an indoor heat exchanger. [Background technology]

[0002] When an air conditioner is used for a long period of time, dust accumulates on the indoor heat exchanger. For this reason, some air conditioners are equipped with a cleaning function that cleans the surface of the indoor heat exchanger on which dust has accumulated. A conventional technique related to an air conditioner equipped with such a cleaning function is disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-300030 A Summary of the Invention [Problem to be solved by the invention]

[0004] When the humidity in the room is low, condensation is less likely to occur on the indoor heat exchanger. If the amount of water droplets to wash off the dust attached to the surface of the indoor heat exchanger is small, the dust and dirt will remain attached to the surface of the indoor heat exchanger, which requires improvement.

[0005] An object of the present invention is to provide an air conditioner that makes it easier for condensation to occur on the surface of an indoor heat exchanger by increasing the humidity in the room. [Means for solving the problem]

[0006] In claim 1, a refrigerant circuit in which a refrigerant circulates and flows, a compressor provided in the refrigerant circuit and capable of compressing a refrigerant; an expansion valve provided in the refrigerant circuit to reduce a pressure of the refrigerant; a four-way valve provided in the refrigerant circuit for switching a flow direction of the refrigerant; an indoor heat exchanger provided in the refrigerant circuit for exchanging heat between the refrigerant and indoor air; An indoor fan that takes in air from the room and blows air into the room; a control unit that controls the compressor, the expansion valve, the four-way switching valve, and the indoor fan to execute a heating operation for heating the indoor air, a cooling operation for cooling the indoor air, a dehumidification operation for dehumidifying the indoor air, a blowing operation for blowing air into the room by the indoor fan without performing heat exchange by the indoor heat exchanger, and a cleaning cooling operation for cleaning the surface of the indoor heat exchanger by causing condensation on the surface of the indoor heat exchanger, When the control unit executes the cleaning cooling operation before a stop duration time measured from the stop of the cooling operation or the dehumidification operation exceeds a preset reference time, The air conditioner is provided in which, before performing the cleaning cooling operation, the heating operation or the air blowing operation is performed in order to return moisture adhering to the indoor heat exchanger to the room.

[0007] As described in claim 2, preferably, as the operation time of the cooling operation or the dehumidification operation that was performed immediately before the measurement of the stop duration is started becomes longer, The operation time of the heating operation or the air blowing operation for returning moisture adhering to the indoor heat exchanger to the room is set long. Effect of the Invention

[0008] In claim 1, when the control unit executes the cleaning cooling operation before the stop duration time measured from the stop of the cooling operation or the dehumidification operation exceeds a preset reference time, the control unit executes the heating operation or the ventilation operation to return moisture adhering to the indoor heat exchanger to the room before executing the cleaning cooling operation. Normally, when the cooling operation or the dehumidification operation is executed, the humidity in the room is low. By executing the heating operation or the ventilation operation before executing the cleaning cooling operation, the moisture is returned to the room. The cleaning cooling operation can be executed after increasing the humidity in the room. The indoor heat exchanger can be efficiently cleaned.

[0009] In claim 2, the operation time of the heating operation or the fan operation is set to be longer as the operation time of the cooling operation or the dehumidification operation executed before the start of the heating operation or the fan operation for returning the moisture adhering to the indoor heat exchanger to the room becomes longer. Normally, as the operation time of the cooling operation or the dehumidification operation becomes longer, the indoor humidity also decreases. When the indoor humidity decreases, the operation time of the heating operation or the fan operation for returning the moisture adhering to the indoor heat exchanger to the room is extended. The moisture return operation can be executed efficiently according to the indoor humidity. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of an air conditioner according to an embodiment. [Diagram 2] FIG. 2 is a block diagram of the air conditioner shown in FIG. [Diagram 3] 2 is a flowchart illustrating the first part of the control content of the air conditioning operation of the air conditioner shown in FIG. [Figure 4] 2 is a flowchart illustrating the latter part of the control content of the air conditioning operation of the air conditioner shown in FIG. [Diagram 5] 4 is a flowchart illustrating the control content of a cleaning operation of the air conditioner shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings.

[0012] <Example> 1 shows an air conditioner 10 (air conditioner) equipped with a refrigerant circuit 11 through which a refrigerant flows. The air conditioner 10 has the function of performing a cooling operation to cool the room R, and a heating operation to warm the room R. The refrigerant circuit 11 includes an outdoor unit 20 arranged outside Ou, and an indoor unit 30 arranged inside the room R. Hereinafter, unless otherwise specified, the direction in which the refrigerant circulates is based on the cooling operation.

[0013] The outdoor unit 20 has a four-way switching valve 21 that switches the direction in which the refrigerant circulates during cooling operation and heating operation, a compressor 22 through which the refrigerant that has passed through this four-way switching valve 21 flows and compresses the refrigerant, an outdoor heat exchanger 23 through which the refrigerant that has been compressed in the compressor 22 and has become high temperature and high pressure flows, a propeller fan 24 that blows air toward the outdoor heat exchanger 23, and an expansion valve 25 that reduces the pressure of the refrigerant that has passed through the outdoor heat exchanger 23.

[0014] The indoor unit 30 is hung on a wall Wa in the room R. The indoor unit 30 has an indoor fan 31 that takes in air from the room and blows air into the room, an indoor heat exchanger 32 that cools the air taken in by the indoor fan 31, and a case 33 that houses the indoor fan 31 and the indoor heat exchanger 32.

[0015] The case 33 has an air outlet 33a which serves as an outlet for the air blown out by the indoor fan 31. A left-right louver 34 for adjusting the left-right direction of the blown air and a top-bottom louver 35 for adjusting the up-down direction of the blown air are arranged in the air outlet 33a.

[0016] Cooling operation will now be described. The refrigerant that has been made high temperature and high pressure by the compressor 22 exchanges heat with outside air in the outdoor heat exchanger 23, releasing heat. At this time, the propeller fan 24 rotates to forcibly flow the outside air around the outdoor heat exchanger 23, promoting the heat exchange. The refrigerant that has passed through the outdoor heat exchanger 23 and released heat is reduced in pressure in the expansion valve 25, and its temperature drops. The refrigerant with the lowered temperature flows to the indoor heat exchanger 32.

[0017] The low-temperature refrigerant that has flowed into the indoor heat exchanger 32 exchanges heat with the air in the room R in the indoor heat exchanger 32, cooling the air in the room R. The cooled air is blown into the room R by the indoor fan 31. The indoor fan 31 forcibly flows the air around the periphery of the indoor heat exchanger 32, promoting heat exchange with the refrigerant. The operating principles of the dehumidification operation that dehumidifies the air in the room and the cleaning cooling operation described below are the same as those of the cooling operation described above.

[0018] During heating operation, the four-way valve 21 switches the flow path of the refrigerant to circulate the refrigerant in the opposite direction to that during cooling operation. Furthermore, the air conditioner 10 also has a function of performing a fan operation in which the indoor fan 31 blows air into the room without performing heat exchange by the indoor heat exchanger 32.

[0019] Fig. 2 shows a control block diagram of the air conditioner device 10 (see Fig. 1). The indoor unit 30 incorporates an indoor control unit 40 (control unit) that controls the indoor fan 31, the left and right louvers 34, and the up and down louvers 35, a room temperature sensor 41 that detects the room temperature, an indicator lamp 42 that displays the operating status by the indoor control unit 40, a remote control transmitting / receiving unit 43 that exchanges predetermined information with the remote control 12, a humidity sensor 46 that detects the humidity in the room, and a human presence sensor 47 that detects a person in the room.

[0020] The indoor control unit 40 has a memory unit 44 in which data received via the remote control transmitter / receiver unit 43, detection values ​​of the room temperature sensor 41, the set temperature and reference time described below, and other specified programs, etc. are stored, as well as timers T1 to T4 which measure the elapsed time of various operations.

[0021] The outdoor unit 20 has an outdoor control unit 45 that is electrically connected to the indoor control unit 40. The indoor control unit 40 is capable of controlling the four-way switching valve 21, the compressor 22, the propeller fan 24, and the expansion valve 25 via the outdoor control unit 45.

[0022] The air conditioner 10 also has a function of performing a cleaning operation to clean dust adhering to the surface of the indoor heat exchanger 32 (see FIG. 1). Operations other than the cleaning operation, specifically, operations for the purpose of conditioning the room by heating operation, cooling operation, etc., are referred to as air conditioning operations. Note that the display state of the indicator lamp 42 differs depending on each operation.

[0023] The cleaning operation includes a cleaning cooling operation in which water droplets are generated on the surface of the indoor heat exchanger 32 by condensation to wash away dust, and a drying operation which is performed after the cleaning cooling operation to dry the surface of the indoor heat exchanger 32.

[0024] Furthermore, the cleaning operation includes a humidity return operation that increases the humidity in the room. By performing the humidity return operation before the cleaning cooling operation, the humidity in the room can be increased and the efficiency of the cleaning cooling operation can be improved. Each operation in the cleaning operation is performed by controlling the compressor 22, the expansion valve 25, the four-way switching valve 21, and the indoor fan 31.

[0025] Please refer to Fig. 3. When a signal to start operation of the air conditioner unit 10 is sent from the remote control 12 (see Fig. 2) to the indoor control unit 40, or based on other programs such as timer operation, the indoor control unit 40 starts operation of the air conditioner unit 10.

[0026] In step st1, it is determined whether an air conditioning operation (an operation other than a cleaning operation) has started.

[0027] When the air conditioning operation is started, in step st2, flag A is cleared. When flag A is cleared, it means that "the air conditioning device 10 is operating." When flag A is set, it means that "the air conditioning device 10 is stopped."

[0028] In step st3, flag B is cleared. The cleared state of flag B means that "the conditions for starting the moisture return operation are not met." The set state of flag B means that "the conditions for starting the moisture return operation are met."

[0029] In step st4, it is determined whether the currently executed operation is a cooling operation or a dehumidifying operation.

[0030] If the operation currently being performed is neither a cooling operation nor a dehumidification operation, for example, if a heating operation or a fan operation is being performed, in step st5, it is determined whether the air conditioning operation has ended.

[0031] When the air conditioning operation ends, in step st6, flag A is set (air conditioning operation stopped) and the process ends (END).

[0032] If it is determined in step st4 that the currently executed operation is the cooling operation or the dehumidification operation, in step st7, the first timer T1 is started from "0".

[0033] In step st8, it is determined whether the cooling operation or the dehumidifying operation has ended.

[0034] Please refer to Fig. 4. When the cooling operation or the dehumidification operation is completed, in step st9, flag A is set (air conditioning operation is stopped).

[0035] In step st10, the first timer T1 is stopped and the time measured by the first timer T1 is stored. This stored time T1 is the operation time during which the cooling operation or the dehumidification operation was performed.

[0036] In step st11, the second timer T2 is started from “0.” The time measured by the second timer T2 is the stop duration that starts from the time when the cooling operation or the dehumidifying operation is stopped.

[0037] In step st12, flag B is set (conditions for moisture return operation are met).

[0038] In step st13, it is determined whether the time measured by the second timer T2 (the duration T2 during which the cooling operation or the dehumidifying operation is stopped) has passed a preset reference time m1 (second timer T2>reference time m1).

[0039] When the stop duration T2 has passed the reference time m1 (second timer T2>reference time m1), in step st14, the second timer T2 is reset.

[0040] In step st15, flag B is turned off (moisture return operation cannot be started), and the process ends (END).

[0041] Please refer to Fig. 5. Next, a case where a command to start a cleaning operation is given will be described. Note that the cleaning operation can be started at any timing regardless of the flow charts shown in Figs.

[0042] In step st16, it is determined whether flag A is set (air conditioning operation is stopped).

[0043] When the air conditioning operation is stopped, in step st17, it is determined whether flag B is set (whether the conditions for starting the moisture return operation are met). As shown in steps st12 to st15 in Fig. 4, the condition for starting the moisture return operation is that the stop duration (the time measured by the second timer T2) that starts from the stop of the cooling operation or the dehumidification operation does not exceed a preset reference time m1.

[0044] If the flag B is set in step st17 (the conditions for starting the moisture return operation are met), the room temperature Tr is detected by the room temperature sensor 41 in step st18.

[0045] In step st19, it is determined whether the room temperature Tr detected in step st18 is lower than a preset reference temperature Trs (room temperature Tr<reference temperature Trs).

[0046] (Moisture return operation by heating operation) If the room temperature Tr is lower than the reference temperature Trs (room temperature Tr<reference temperature Trs), in step st20, the heating operation is started as the moisture return operation. In the heating operation as the moisture return operation, the air volume, the set temperature, etc. may be set to be larger than in the normal heating operation.

[0047] After the heating operation is started, in step st21, the third timer T3 is started from "0".

[0048] In step st22, the third timer T3 determines whether a preset set time Ts1 has elapsed (third timer T3>set time Ts1). Note that, as the measurement time of the first timer T1 stored in step st10 (the operation time of the cooling operation or dehumidification operation performed immediately before the measurement of the stop duration T2 is started) becomes longer, the set time Ts1 is set longer.

[0049] When the third timer T3 has elapsed the set time Ts1 (third timer T3>set time Ts1), the cleaning cooling operation is executed in step st23, and then the drying operation is executed in step st24, and the operation is terminated (END). Detailed explanations of the cleaning cooling operation and the drying operation are omitted.

[0050] (Moisture return operation by fan operation) When the room temperature Tr is equal to or higher than a preset reference temperature Trs (room temperature Tr≧reference temperature Trs), in step st25, the air blowing operation is started as a moisture returning operation.

[0051] In step st26, the fourth timer T4 is started from "0".

[0052] In step st27, the fourth timer T4 judges whether a preset set time Ts2 has elapsed (fourth timer T4>set time Ts2). Note that, as the measurement time of the first timer stored in step st10 (the operation time of the cooling operation or dehumidification operation performed immediately before the measurement of the stop duration T2 is started) becomes longer, the set time Ts2 is set longer.

[0053] When the fourth timer T4 has elapsed the set time Ts2 (fourth timer T4>set time Ts2), the cleaning cooling operation is executed in step st23, and then the drying operation is executed in step st24, and the operation is terminated (END). Detailed explanations of the cleaning cooling operation and the drying operation are omitted.

[0054] (Effects of the embodiment) (Moisture return operation) Refer to Fig. 5. When flag B is set in step st17, that is, as shown in steps st12 to st15 in Fig. 4, the start condition of the moisture return operation is that when the stop duration (time measured by the second timer T2) from when the cooling operation or the dehumidification operation is stopped does not exceed a preset reference time m1, the heating operation in step st20 or the fan operation in step st25 is performed to return moisture adhering to the indoor heat exchanger 32 to the room before performing the cleaning cooling operation in step st23.

[0055] When the cooling operation or the dehumidification operation is being performed (see step st4), the humidity in the room is low. Before performing the cleaning cooling operation in step st23, the heating operation in step st20 or the fan operation in step st25 is performed, so that the humidity returns to the room. The cleaning cooling operation can be performed after increasing the humidity in the room. The indoor heat exchanger 32 can be efficiently cleaned.

[0056] (Moisture return operation time) In addition, the longer the measurement time of the first timer T1 stored in step st10 (the operating time of the cooling operation or dehumidification operation performed immediately before the measurement of the stop duration T2 began), the longer the setting time Ts1 of step st22 or the setting time Ts2 of step st27 is set.

[0057] Normally, as the operating time of the cooling or dehumidifying operation becomes longer, the indoor humidity also decreases. When the indoor humidity drops significantly, the operating time of the heating or fan operation (set times Ts1, Ts2) is extended to return the moisture adhering to the indoor heat exchanger 32 to the room. The moisture return operation can be performed efficiently according to the indoor humidity.

[0058] By using the humidity sensor 46, when the indoor humidity is equal to or higher than a predetermined humidity, the cleaning cooling operation of step st23 may be started without executing the moisture return operation (steps st20, st25). By using the humidity sensor 46, when the humidity rise becomes gentle during the operation time of the moisture return operation (steps st20, st25), the moisture return operation may be ended before the operation time (set times Ts1, Ts2) has elapsed.

[0059] Furthermore, by using the human presence sensor 47, the moisture return operation may be executed only when no one is present in the room (steps st20 and st25).

[0060] As long as the functions and effects of the present invention are exhibited, the present invention is not limited to the examples. [Industrial Applicability]

[0061] The air conditioner of the present invention is suitable for use as a home air conditioner. [Explanation of symbols]

[0062] 10…Air conditioning equipment (air conditioner) 11...Refrigerant circuit 21...Four-way switching valve 22...Compressor 25…Expansion valve 32…Indoor heat exchanger 40...Indoor control unit (control unit) 41…Room temperature sensor T1: The operation time of the cooling or dehumidification operation that was performed immediately before the measurement of the stop duration started T2: The duration of the stoppage measured from the time the cooling or dehumidification operation is stopped m1: Pre-set reference time Ts1: Heating operation setting time (operating time) Ts2…Setting time for fan operation (operating time)

Claims

1. a refrigerant circuit through which a refrigerant circulates; a compressor provided in the refrigerant circuit and capable of compressing a refrigerant; an expansion valve provided in the refrigerant circuit to reduce a pressure of the refrigerant; a four-way valve provided in the refrigerant circuit for switching a flow direction of the refrigerant; an indoor heat exchanger provided in the refrigerant circuit for exchanging heat between the refrigerant and indoor air; An indoor fan that takes in air from the room and blows air into the room; a control unit that controls the compressor, the expansion valve, the four-way switching valve, and the indoor fan to execute a heating operation for heating the indoor air, a cooling operation for cooling the indoor air, a dehumidification operation for dehumidifying the indoor air, a blowing operation for blowing air into the room by the indoor fan without performing heat exchange by the indoor heat exchanger, and a cleaning cooling operation for cleaning the surface of the indoor heat exchanger by causing condensation on the surface of the indoor heat exchanger, Before the stop duration time measured from the stop of the cooling operation or the dehumidification operation exceeds a preset reference time, When a signal to start the cleaning cooling operation is manually transmitted to the control unit, Before performing the cleaning cooling operation, the heating operation or the air blowing operation is performed to return moisture adhering to the indoor heat exchanger to the room; After the stop duration exceeds the reference time, When a signal to start the cleaning cooling operation is manually transmitted to the control unit, The control unit executes the cleaning cooling operation without executing the heating operation or the air blowing operation.

2. As the operation time of the cooling operation or the dehumidification operation that was performed immediately before the measurement of the stop duration is started becomes longer, The air conditioner according to claim 1 , wherein an operation time of the heating operation or the air blowing operation for returning moisture adhering to the indoor heat exchanger to the room is set long.

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