JP6022291B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner that performs a defrosting operation while performing a heating operation.

  Conventionally, in this type, an air conditioner that performs a heating operation by flowing a refrigerant that has been heated to high temperature by a compressor in a refrigeration cycle into an indoor heat exchanger and supplying indoor air to the indoor heat exchanger by an indoor fan. When the outdoor air exchanger where the outside air temperature decreases and the low-temperature refrigerant flows during heating operation is frosted and the temperature detected by the outdoor heat exchanger sensor falls below the defrosting start temperature, the indoor fan and the outdoor A defrosting operation for defrosting the outdoor heat exchanger was performed by stopping the fan and causing the refrigerant to flow in the opposite direction. (For example, Patent Document 1)

JP 2012-78065 A

  However, with such conventional devices, if it is determined that the room temperature has reached the set temperature set by the remote controller in general, the heating operation is interrupted so that the room temperature does not rise too much. When the outside temperature is low with a low heating load, such as when the room is heated together with other heaters, the heating operation is temporarily suspended because the room temperature has risen above the set temperature. After that, when the room temperature decreases and the heating operation resumes, the temperature of the outdoor heat exchanger decreases immediately after the heating operation resumes, reaches the defrosting start temperature, starts the defrosting operation, and interrupts the heating operation again. Therefore, the heating feeling of the user may be lost due to frequent intermittent heating operation.

  In order to solve the above problems, in claim 1 of the present invention, a compressor that compresses a refrigerant, an indoor heat exchanger that is disposed indoors, an expansion valve that decompresses the refrigerant, and outdoor heat that is disposed outdoors. A refrigerating cycle in which the exchanger is connected in an annular manner, a flow path switching unit that is installed in the middle of the refrigerating cycle and changes the flow direction of the refrigerant, an indoor fan that supplies indoor air to the indoor heat exchanger, An outdoor fan that supplies the air to the outdoor heat exchanger, an outdoor heat exchange sensor that detects the temperature of the outdoor heat exchanger, a room temperature sensor that detects the indoor temperature, and a desired indoor temperature A remote controller for setting the temperature, and a heating operation in which the indoor fan and the outdoor fan are driven so that the set temperature is set by the remote controller, and the compressor is driven to flow the refrigerant to the indoor heat exchanger. Before and after When a temperature equal to or lower than the first defrosting start temperature is detected by the outdoor heat exchange sensor, the indoor fan and the outdoor fan are stopped, and the defrosting operation is performed by causing the flow path switching means to flow the refrigerant in the direction opposite to that during the heating operation. An air conditioner including a control unit for controlling the control unit, wherein the control unit detects a value equal to or higher than a set temperature set by the remote controller during the heating operation, and the outdoor heat exchange sensor detects the value. When a temperature equal to or lower than the second defrost start temperature higher than the first defrost start temperature is detected, the defrost operation is started.

  Further, in claim 2, the control unit detects a value equal to or higher than a set temperature set by the remote controller during the heating operation, and an output of the compressor during the heating operation is a predetermined value or less. When the outdoor heat exchange sensor detects a temperature not higher than the second defrost start temperature that is higher than the first defrost start temperature by a predetermined value, the defrost operation is started.

  According to a third aspect of the present invention, the control unit detects a value equal to or higher than a set temperature set by the remote controller during the heating operation, and the output of the compressor during the heating operation is a predetermined value or less. The defrosting operation is started when the outdoor heat exchange sensor detects a temperature equal to or lower than the second defrosting start temperature that is higher than the first defrosting start temperature by a predetermined value. To do.

According to a fourth aspect of the present invention, there is provided a refrigeration in which a compressor that compresses refrigerant, an indoor heat exchanger that is disposed indoors, an expansion valve that decompresses the refrigerant, and an outdoor heat exchanger that is disposed outdoors are connected in a ring shape. A flow path switching means that is installed in the middle of the refrigeration cycle to change the flow direction of the refrigerant, an indoor fan that supplies indoor air to the indoor heat exchanger, and outdoor air to the outdoor heat exchanger An outdoor fan to be supplied, an outdoor heat exchange sensor for detecting the temperature of the outdoor heat exchanger, a room temperature sensor for detecting a room temperature, a remote controller for setting a set temperature so as to be a desired room temperature, and the remote controller The indoor fan and the outdoor fan are driven so that the set temperature is set in step S1, and the compressor is driven to perform a heating operation in which the refrigerant flows to the indoor heat exchanger, and the outdoor heat exchange sensor First defrost opening An air provided with a control unit for controlling a defrosting operation in which the indoor fan and the outdoor fan are stopped when a temperature equal to or lower than the temperature is detected, and the refrigerant is caused to flow in a direction opposite to that during the heating operation by the flow path switching unit. In the conditioner, the control unit is configured such that the room temperature sensor detects a value equal to or higher than a set temperature set by the remote controller during the heating operation, and the output of the compressor during the heating operation is a predetermined value or less. If there is, a rate of change that is a rate of change of the temperature detected by the outdoor heat exchange sensor in a predetermined time is calculated, and if the rate of change is equal to or less than a predetermined negative value, the defrosting operation is started. .

According to a fifth aspect of the present invention, the control unit detects a value equal to or higher than a set temperature set by the remote controller during the heating operation, and the output of the compressor during the heating operation is a predetermined value or less. If the state continues for a predetermined time or more, a change rate that is a change rate of the temperature detected by the outdoor heat exchange sensor in the predetermined time is calculated, and if the change rate is a negative negative value or less, The defrosting operation is started.

  According to the first aspect of the present invention, the room temperature sensor detects a value equal to or higher than the set temperature set by the remote controller during heating operation, and the second defrost start is higher than the first defrost start temperature by the outdoor heat exchange sensor. When a temperature below the temperature is detected, the defrosting operation is started, so the outdoor heat can be removed without reducing the time required for the heating operation by performing the defrosting operation when the room temperature is higher than the set temperature and there is no heating request. The defrosting of the exchanger can be performed, the loss of the user's feeling of heating can be prevented, and the defrosting is performed in a state where the amount of frosting of the outdoor heat exchanger is small, so that the defrosting time can be shortened. it can.

  According to claim 2, the room temperature sensor detects a value equal to or higher than the set temperature set by the remote controller during the heating operation, the compressor output during the heating operation is equal to or less than a predetermined value, and the outdoor heat exchange sensor When a temperature equal to or lower than the second defrosting start temperature that is higher than the first defrosting start temperature is detected, the defrosting operation is started, so that the room temperature becomes higher than the set temperature and there is no heating request, and the compressor If the output is low and the heating load is small, the defrosting start temperature is raised and the defrosting operation is performed at an early stage, so that the defrosting operation can be performed when the room temperature is sufficiently warm. It is possible to prevent the person from losing the feeling of heating and to reduce the defrosting time because the defrosting is performed in a state where the amount of frost formation on the outdoor heat exchanger is small.

  According to the third aspect, the room temperature sensor detects a value equal to or higher than the set temperature set by the remote controller during the heating operation, and the state where the compressor output during the heating operation is equal to or lower than the predetermined value continues for a predetermined time or longer. When the outdoor heat exchange sensor detects a temperature equal to or lower than the second defrost start temperature that is higher than the first defrost start temperature by a predetermined value, the defrost operation is started. If there is no request and the compressor output is low and the heating load is low for a predetermined time or longer and the room temperature is stable, the defrosting start temperature is raised and the defrosting operation is performed early. Therefore, the defrosting operation can be performed when there is little fluctuation in the room temperature and the room temperature is not excessively lowered by the defrosting operation, and the loss of heating feeling of the user can be prevented, and the frosting of the outdoor heat exchanger can be prevented. Defrosting is performed in a small amount Because, the defrosting time can also be shortened.

According to claim 4, if the room temperature sensor detects a value equal to or higher than the set temperature set by the remote controller during heating operation, and the output of the compressor during heating operation is equal to or less than a negative predetermined value, The rate of change, which is the rate of change of the temperature detected by the outdoor heat exchange sensor for a predetermined time, is calculated, and if the rate of change is less than the predetermined value, the defrosting operation is started. The room temperature is sufficient by starting the defrosting operation when there is no request and the outside air temperature decreases in the state where the output of the compressor is low and the heating load is small, and the detection temperature of the outdoor heat exchange sensor suddenly decreases. The defrosting operation can be performed before the amount of frost formation on the outdoor heat exchanger increases in a warmed state, and the loss of the user's feeling of heating can be prevented, and the amount of frost formation on the outdoor heat exchanger is small Because defrosting is performed in the state, at the time of defrosting It can also be shortened.

According to the fifth aspect, the room temperature sensor detects a value equal to or higher than the set temperature set by the remote controller during the heating operation, and a state where the compressor output during the heating operation is equal to or lower than the predetermined value continues for a predetermined time or more. If so, the rate of change, which is the rate of change of the temperature detected by the outdoor heat exchange sensor for a predetermined time, is calculated, and if the rate of change is equal to or less than a predetermined negative value, the defrosting operation is started. When the room temperature is stable for a predetermined time or longer when the compressor output is low and the heating load is low for a predetermined time or longer, the outside air temperature decreases and the detected temperature of the outdoor heat exchange sensor By starting the defrosting operation due to a sudden drop, the defrosting operation is performed before the amount of frost formation in the outdoor heat exchanger increases when there is little risk of room temperature fluctuations and there is no risk of the room temperature dropping excessively due to the defrosting operation. Can do and use Loss of feeling of warmth with can be prevented, since the defrost state frost of the outdoor heat exchanger is small is made, it can be shortened defrosting time.

Schematic configuration diagram showing an embodiment of the present invention Control block diagram of the first embodiment of the invention Flowchart for explaining the operation of the first embodiment of the invention Control block diagram of the second embodiment of the invention Flow chart for explaining the operation of the second embodiment of the invention Control block diagram of the third embodiment of the invention Flowchart for explaining the operation of the third embodiment of the invention

Next, an embodiment of an air conditioner to which the present invention is applied will be described with reference to the drawings.
1 is an indoor unit installed indoors, 2 is an outdoor unit installed outdoor, and the refrigerant flows in the refrigeration cycle 3 in which the indoor unit 1 and the outdoor unit 2 are connected by piping, It constitutes an air conditioner capable of heating operation.

  4 is an indoor heat exchanger in which refrigerant flows in a plurality of pipes, 5 is a cross-flow fan as an indoor fan that supplies indoor air to the indoor heat exchanger 4, and 6 is a room temperature for detecting the indoor temperature. Each of the sensors is provided in the indoor unit 1 and distributes high-temperature or low-temperature refrigerant to the indoor heat exchanger 4 and drives the cross-flow fan 5 to supply the indoor air to the indoor heat exchanger 4. Thus, air conditioning of the room provided with the indoor unit 1 is performed.

  7 is a compressor that compresses the refrigerant to high temperature and high pressure, 8 is a four-way valve as flow path switching means that changes the flow direction of the refrigerant, 9 is an expansion valve that expands the refrigerant to low temperature and low pressure, 10 is inside An outdoor heat exchanger in which a refrigerant flows through a plurality of pipes provided, 11 is a blower fan as an outdoor fan that supplies outside air toward the outdoor heat exchanger 10, and 12 is a temperature of the outdoor heat exchanger 10. The outdoor heat exchange sensors to be detected are provided in the outdoor unit 2, respectively.

  13 is a remote controller for setting the operation mode and set temperature by the indoor unit 1, an operation button 14 for instructing start and stop of operation, and an operation switch button 15 for switching each operation mode such as heating operation and cooling operation. A temperature setting button 16 for changing the set temperature in each operation mode and a display 17 for displaying the room temperature, the set temperature, the current time, and the like are provided.

  Reference numeral 18 denotes a control unit that is provided in the outdoor unit 2 and is configured by a microcomputer that gives instructions to each functional device. By switching the direction of the four-way valve 8, switching between the cooling operation and the heating operation is possible. The temperature comparison means 19 is provided for comparing the room temperature detected in step 1 and the temperature of the outdoor heat exchanger 10 detected by the outdoor heat exchange sensor 12 with a predetermined value.

Next, a specific operation in one embodiment of the present invention will be described.
When the heating operation is selected by the operation switching button 15 installed on the remote controller 13, the four-way valve 8 is switched to the direction shown by the solid line in FIG. 1, and the compressor 7 is driven, compressed by the compressor 7, and compressed at high temperature and high pressure. The refrigerant that has flowed in the direction of the solid arrow in FIG. 1 causes the indoor heat exchanger 3 to function as a condenser, so that the indoor air supplied by the cross flow fan 5 is heated and the indoor temperature is increased. Wind is blown.

  The refrigerant that has flowed out of the indoor heat exchanger 3 is expanded by the expansion valve 9, becomes low temperature and low pressure, flows into the outdoor heat exchanger 10, and the refrigerant that flows into the outdoor heat exchanger 10 that functions as an evaporator is supplied by the blower fan 11. It evaporates by the outdoor air, changes its state to a gas refrigerant, and flows into the compressor 7. As described above, the refrigerant flows in the refrigeration cycle 3 so that the heating operation can be performed.

  Further, when the cooling operation is selected by the operation switching button 15 installed on the remote controller 13, the four-way valve 8 is switched to the direction indicated by the broken line in FIG. The refrigerant that has been compressed at the high temperature and high pressure flows in the direction of the broken arrow and flows into the outdoor heat exchanger 10, and the refrigerant that flows into the outdoor heat exchanger 10 that functions as a condenser is supplied to the outdoor fan 11. Condensed by air.

  The refrigerant flowing into the expansion valve 9 from the outdoor heat exchanger 10 is expanded and becomes low-temperature and low-pressure, and the refrigerant flows into the indoor heat exchanger 4 that functions as an evaporator and absorbs the heat of the indoor air supplied by the crossflow fan 5. The state changes to a gas refrigerant and flows into the compressor 7. In this way, the refrigerant flows in the refrigeration cycle 3 so that the cooling operation can be performed.

  Further, in the heating operation and the cooling operation, when the room temperature approaches the set temperature set by the temperature setting button 16 of the remote controller 13, the output of the compressor 7 is decreased to prevent an excessive increase or decrease in the room temperature. The room temperature can be maintained near the set temperature.

  Further, during the cooling operation or the heating operation, the control unit 18 compares the set temperature set by the temperature setting button 16 of the remote controller 13 with the room temperature detected by the room temperature sensor 6 by the temperature comparison unit 19. If it is determined that the room temperature has reached the set temperature, the compressor 7, the cross flow fan 5, and the blower fan 11 are stopped, and the temperature control is stopped to temporarily stop the cooling operation or the heating operation. After that, when it is determined that the room temperature detected by the room temperature sensor 6 has deviated from the set temperature, the cooling operation or the heating operation is resumed, so that excessive air conditioning in the room is prevented and an increase in power consumption is prevented.

Next, 1st Embodiment of the defrost operation which removes the frost formation of the outdoor heat exchanger 10 is described based on the flowchart of FIG.
When the heating operation is selected by the operation switching button 15 installed on the remote controller 13, the set temperature is set to 20 ° C. by the temperature setting button 16, and the operation button 14 is operated to start the heating operation (step S101), the control is performed. The unit 18 compares the temperature detected by the outdoor heat exchange sensor 12 with a predetermined first defrosting start temperature (for example, −10 ° C.) by the temperature comparison means 19 (step S102). If the detected value is −10 ° C. or lower, it is assumed that the temperature of the outdoor heat exchanger 10 is low and the amount of frost formation is large, and the refrigerant that has become high temperature and high pressure in the compressor 7 by switching the four-way valve 8 is transferred to the outdoor heat exchanger 10. A defrosting operation for inflowing and melting frost is started (step S103).

  Here, the defrosting operation will be described. When the temperature detected by the outdoor heat exchange sensor 12 is not more than a predetermined value such as −10 ° C., the temperature of the outdoor heat exchanger 10 is low, and the amount of frost formation is increased. If the heating operation is continued as it is, the amount of frost formation is further increased and the heating efficiency is lowered. Therefore, the control unit 18 switches the valve direction of the four-way valve 8 and causes the refrigerant to flow in the same direction as in the cooling operation, thereby compressing. The refrigerant heated to high temperature and high pressure in the machine 7 flows into the outdoor heat exchanger 10 to perform defrosting to dissolve frost.

  On the other hand, if the detected value of the outdoor heat exchange sensor 12 is higher than −10 ° C. in step S102, the control unit 18 confirms the room temperature detected by the room temperature sensor 6 (step S104), and the detected room temperature is set. If the detected room temperature is 20 ° C. or higher when compared with the temperature of 20 ° C. or higher (step S105), the temperature control for stopping the compressor 7, the cross flow fan 5 and the blower fan 11 is performed. Stop is performed (step S106), and if the detected room temperature is less than 20 ° C., the detection value of the outdoor heat exchange sensor 12 is confirmed again in step S102.

  When the temperature control is stopped in step S106, the controller 18 compares the temperature detected by the outdoor heat exchange sensor 12 and the second defrost start temperature (for example, −5 ° C.) higher than the first defrost start temperature. 19 (step S107), and if the temperature detected by the outdoor heat exchange sensor 12 is −5 ° C. or lower, the direction of the four-way valve 8 is switched and then the compressor 7 is driven to start the defrosting operation. (Step S108).

  As described above, when the temperature detected by the outdoor heat exchange sensor 12 at the time of temperature control stop becomes equal to or lower than the second defrost start temperature higher than the first defrost start temperature, the defrost operation is started, so that the outside air temperature is reduced. Air conditioning in a frosting condition due to low temperature and low set temperature during heating operation, or heating indoors using a heater other than the indoor unit 1 such as a fan heater When the heating load of the machine is small, it is possible to extend the time until the defrosting operation start condition is reached after the temperature control is stopped and the heating operation is restarted, and the heating operation time can be extended. Therefore, the loss of the user's feeling of heating is prevented, and the defrosting is performed in a state where the amount of frost formation on the outdoor heat exchanger 10 is small, so that the defrosting operation time can also be shortened.

Next, a second embodiment of the present invention will be described based on the control block diagram of FIG.
20 is an output comparing means for comparing the output of the compressor 7 driven during the cooling operation and the heating operation with a predetermined value, and 21 is always calculating the average value of the compressor 7 for a predetermined time of 20 minutes from the start of the heating operation. The average output calculation means to be updated is provided in the control unit 18 and the other components are the same as those in the first embodiment, and the description thereof will be omitted.

Next, the defrost operation which removes frost formation of the outdoor heat exchanger 10 of 2nd Embodiment is demonstrated based on the flowchart of FIG.
Steps S101 to S106 are the same as those in the first embodiment, and thus description thereof is omitted.
When the temperature adjustment is stopped in step S106, the control unit 18 checks the output of the compressor 7 immediately before the temperature adjustment is stopped (step S201), and the output immediately before the temperature adjustment is stopped and a predetermined value of 30 Hz are output comparing means 20. (Step S202), if it is determined that the compressor 7 immediately before the temperature adjustment stop is driven at a low output of 30 Hz or less, the process proceeds to the next step, and if the output immediately before the temperature adjustment exceeds 30 Hz, the control is performed. Exit.

  If it is determined in step S202 that the output of the compressor 7 immediately before the temperature adjustment is stopped is 30 Hz or less, the control unit 18 calculates the average output of the compressor 7 for 20 minutes before the temperature adjustment is stopped by the average output calculation means 21. The result is confirmed (step S203), and the average output of the calculation result is compared with a predetermined value of 35 Hz by the output comparison means 20 (step S204), and the compressor 7 is driven at a low output of 35 Hz or less. If it is determined that it has been, the process proceeds to the next step. If the average output exceeds 35 Hz, the control is terminated.

  If it judges that the average output of the compressor 7 is 35 Hz or less in step S204, the control part 18 will be the 2nd defrost start temperature (for example, higher than the temperature detected with the outdoor heat exchanger sensor 12 and the said 1st defrost start temperature). −5 ° C.) is compared by the temperature comparison means 19 (step S205), and if the temperature detected by the outdoor heat exchange sensor 12 is −5 ° C. or less, the defrosting operation is started (step S206).

  As described above, if the output of the compressor 7 immediately before the stop of the temperature control is equal to or less than the predetermined value and the average output of the compressor 7 for 20 minutes before the stop of the temperature control is equal to or less than the predetermined value, the heating load is small and the temperature control is stopped. It is determined that the previous room is sufficiently warm, and the defrosting operation is started earlier by starting the defrosting operation when the temperature becomes equal to or lower than the second defrosting start temperature that is higher than the first defrosting start temperature by a predetermined value. In the state where the time required for the defrosting operation is shortened and the decrease in the room temperature can be minimized, the loss of the user's feeling of heating is prevented, and the amount of frost formation in the outdoor heat exchanger 10 is small. Since defrosting is performed, the defrosting operation time can also be shortened.

It will now be described with reference to the control block diagram of FIG. 6 a third embodiment of the present invention.
Reference numeral 22 denotes change rate calculation means for constantly calculating and updating the change rate a, which is the rate of change in temperature from the change value of temperature in 10 minutes, which is the predetermined time of the outdoor heat exchange sensor 12, using Equation (1). Since these components are the same as those in the first embodiment and the second embodiment, description thereof will be omitted.
(1) Change rate a = change value of temperature / predetermined time

It will now be described with reference to the flowchart of FIG. 7 for defrosting operation to remove frost in the outdoor heat exchanger 10 of the third embodiment.
Since Steps S101 to S106 and Steps S201 to S204 are the same controls as those in the first and second embodiments, description thereof will be omitted. If it is determined in step S204 that the average output of the compressor 7 is 35 Hz or less, the control unit 18 calculates a change rate calculation means for the change rate a of the temperature detected by the outdoor heat exchange sensor 12 for 10 minutes before the temperature adjustment is stopped. The numerical value calculated in 22 is confirmed (step S301).

  When the change rate a is confirmed in step S301, the control unit 18 compares the change rate a with a predetermined value (for example, -0.2) (step S302), and the change rate a is a predetermined value of -0.2 or less. If so, the defrosting operation is started (step S303).

  If the outdoor temperature rapidly decreases during the heating operation, the temperature of the outdoor heat exchanger 10 decreases quickly, and there is a concern that the amount of frost formation will increase, but the change detected by the outdoor heat exchange sensor 12 over 10 minutes Since the defrosting operation is started based on the rate of change calculated from the value, the defrosting operation is started early because the frost formation of the outdoor heat exchanger 10 may increase in the future. The defrosting of the exchanger 10 can be completed, and efficient defrosting that can prevent the occurrence of the remaining defrosting is enabled.

As described above, the output of the compressor 7 immediately before the temperature adjustment stop is equal to or less than the predetermined value, the average output of the compressor 7 for 20 minutes before the temperature adjustment stop is equal to or less than the predetermined value, and the outdoor heat exchange sensor 12 at the predetermined time. If the rate of change calculated from the detected temperature change value is less than or equal to the specified value, the defrosting operation is started, so the outdoor temperature drops rapidly when the heating load is small and the room temperature is stable near the set temperature. Then, it is determined based on the rate of change that the amount of frost formation in the outdoor heat exchanger 10 may increase, and the time required for the defrosting operation is shortened by starting the defrosting operation at an early stage. The decrease can be minimized, and loss of the user's feeling of heating can be prevented.

  In the above embodiment, the defrosting start temperature is raised or detected by the outdoor heat exchange sensor 12 based on the output of the compressor 7 immediately before the temperature adjustment is stopped and the average output of the compressor 7 for 20 minutes before the temperature adjustment is stopped. Although the control for starting the defrosting operation at the rate of temperature change is performed, the present invention is not limited to this. For example, if the average value of the room temperature detected by the room temperature sensor 6 is near the set temperature, the room temperature is stable. Even in the control of determining that the room temperature is less likely to be lowered by the defrosting operation and increasing the defrosting start temperature by a predetermined value or starting the defrosting operation based on the rate of change of the temperature detected by the outdoor heat exchange sensor 12. It ’s good.

  In the present embodiment, the first defrost start temperature is set to −10 ° C., the second defrost start temperature is set to −5 ° C., and the defrost start temperature is increased or the temperature detected by the outdoor heat exchange sensor 12. For the defrosting start condition based on the rate of change in temperature, the output immediately before stopping the temperature adjustment is 30 Hz or less, the average output for 20 minutes after the temperature control of the compressor 7 is stopped is 35 Hz or less, and detected by the outdoor heat exchange sensor 12 for 10 minutes. Although the temperature change rate is -0.2 or less, the present invention is not limited to the numerical values shown here, and the numerical values may be changed without departing from the content of the present invention.

DESCRIPTION OF SYMBOLS 1 Indoor unit 2 Outdoor unit 3 Refrigeration cycle 4 Indoor heat exchanger 5 Cross flow fan 6 Room temperature sensor 7 Compressor 8 Four-way valve 9 Expansion valve 10 Outdoor heat exchanger 11 Blower fan 12 Outdoor heat exchange sensor 13 Remote control 18 Control part

Claims (5)

  A compressor that compresses the refrigerant, an indoor heat exchanger that is disposed indoors, an expansion valve that decompresses the refrigerant, and an outdoor heat exchanger that is disposed outdoors, and a refrigeration cycle, A flow path switching means that is installed in the middle and changes the flow direction of the refrigerant, an indoor fan that supplies indoor air to the indoor heat exchanger, an outdoor fan that supplies outdoor air to the outdoor heat exchanger, and An outdoor heat exchanger sensor for detecting the temperature of the outdoor heat exchanger, a room temperature sensor for detecting the temperature of the room, a remote controller for setting a set temperature to be a desired room temperature, and a set temperature set by the remote controller The indoor fan and the outdoor fan are driven so that the compressor is driven to cause the refrigerant to flow to the indoor heat exchanger, and the outdoor heat exchange sensor uses the outdoor heat exchange sensor to lower the first defrost start temperature. Check the temperature of Then, in the air conditioner including the control unit that controls the defrosting operation in which the indoor fan and the outdoor fan are stopped and the flow path switching unit causes the refrigerant to flow in a direction opposite to that during the heating operation. The unit detects a value equal to or higher than a set temperature set by the remote controller during the heating operation, and is equal to or lower than a second defrost start temperature higher than the first defrost start temperature by the outdoor heat exchange sensor. When the temperature is detected, the defrosting operation is started.   The control unit detects a value equal to or higher than a set temperature set by the remote controller during the heating operation, the output of the compressor during the heating operation is a predetermined value or less, and the outdoor heat 2. The air conditioner according to claim 1, wherein the defrosting operation is started when a temperature equal to or lower than the second defrost start temperature that is higher than the first defrost start temperature by a predetermined value is detected by an alternating sensor.   The control unit detects a value equal to or higher than a set temperature set by the remote controller during the heating operation, and the compressor output during the heating operation is not more than a predetermined value for a predetermined time or longer. When the outdoor heat exchange sensor detects a temperature equal to or lower than the second defrost start temperature that is higher than the first defrost start temperature by a predetermined value, the defrost operation is started. Item 3. An air conditioner according to Item 2. A compressor that compresses the refrigerant, an indoor heat exchanger that is disposed indoors, an expansion valve that decompresses the refrigerant, and an outdoor heat exchanger that is disposed outdoors, and a refrigeration cycle, A flow path switching means that is installed in the middle and changes the flow direction of the refrigerant, an indoor fan that supplies indoor air to the indoor heat exchanger, an outdoor fan that supplies outdoor air to the outdoor heat exchanger, and An outdoor heat exchanger sensor for detecting the temperature of the outdoor heat exchanger, a room temperature sensor for detecting the temperature of the room, a remote controller for setting a set temperature to be a desired room temperature, and a set temperature set by the remote controller The indoor fan and the outdoor fan are driven so that the compressor is driven to cause the refrigerant to flow to the indoor heat exchanger, and the outdoor heat exchange sensor uses the outdoor heat exchange sensor to lower the first defrost start temperature. Check the temperature of Then, in the air conditioner including the control unit that controls the defrosting operation in which the indoor fan and the outdoor fan are stopped and the flow path switching unit causes the refrigerant to flow in a direction opposite to that during the heating operation. When the room temperature sensor detects a value equal to or higher than the set temperature set by the remote controller during the heating operation, and the output of the compressor during the heating operation is equal to or less than a predetermined value, the unit An air conditioner that calculates a rate of change, which is a rate of change in temperature detected by the outdoor heat exchange sensor, and starts the defrosting operation if the rate of change is equal to or less than a predetermined negative value. The control unit detects a value equal to or higher than a set temperature set by the remote controller during the heating operation, and the compressor output during the heating operation is not more than a predetermined value for a predetermined time or longer. If so, a rate of change, which is a rate of change of the temperature detected by the outdoor heat exchange sensor in a predetermined time, is calculated, and if the rate of change is less than a predetermined negative value, the defrosting operation is started. The air conditioner according to claim 4.

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