JP2007155245A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner capable of surely executing a low-temperature operation at a temperature lower than a comfortable temperature and free from freezing a room during the cold months, and a defrosting operation in the low-temperature operation. <P>SOLUTION: This air conditioner comprises an indoor fan for supplying heat-exchanged air into the room, and a compressor compressing a refrigerant and circulating the same through routes respectively corresponding to a cooling operation and a heating operation. When frost formation on an outdoor heat exchanger is detected (S13, 21), defrosting is performed (S23). Further this air conditioner has a means for receiving a command to execute the low-temperature operation for heating (S5) at a set temperature (S1) lower than the comfortable temperature and free from freezing the room during the cold months, and a means for continuing an operation of the indoor fan (S19) regardless of the stop of the compressor (S17) and a temperature of an indoor heat exchanger, during the execution of the low-temperature operation, and stopping the indoor fan when the defrosting is performed (S23) during the execution of the low-temperature operation, and the defrosting is performed until a temperature of the outdoor heat exchanger reaches a prescribed temperature, when the defrosting is performed (S23) during the execution of low-temperature operation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an air conditioner that performs a cooling operation and a heating operation, and more particularly, to a separate type air conditioner that includes an outdoor unit and an indoor unit.

In the conventional air conditioner heating operation, when the air volume is automatically adjusted, when the detected room temperature approaches the set temperature, the output of the compressor of the heat pump is reduced and there is a difference depending on the model, but to maintain the blowing temperature Also, reduce the air volume of the indoor fan.
In the separate type or the like, as shown in FIG. 1, the indoor unit 7 is generally mounted above the wall, and if the air volume of the indoor fan is reduced too much, warm air that is lighter than the surrounding air will not reach the floor. There is a limit to the amount of air that can be dropped. However, in the inverter type etc., the frequency of the inverter that drives the compressor is lowered (output is lowered), so naturally the temperature of the hot air is lowered, and the temperature difference and weight difference from the surroundings are also reduced. Warm air can reach the floor even with a small air flow from the indoor fan.

In addition, when the outdoor temperature is low during heating operation, a phenomenon of frost formation on the outdoor heat exchanger is observed. When time elapses, the outdoor heat exchanger is blocked by frost and air does not pass through, and heat exchange cannot be performed, so a defrosting operation is performed. In addition, an outdoor heat exchanger temperature measuring device (defrosting thermo) is added to the outdoor heat exchanger, which is used for controlling the defrosting operation.
The start time of the defrosting operation is that when the outdoor heat exchanger is blocked, the measured temperature of the outdoor heat exchanger temperature measuring device decreases sharply. It is determined based on the fact that the difference between and changes rapidly.

In the defrosting operation, defrosting (cycle defrosting) is generally performed by switching the four-way valve of the heat pump to make a cooling cycle and flowing hot gas to the outdoor heat exchange equipment side.
The defrosting operation is terminated when the frost is removed if the measured temperature of the outdoor heat exchanger temperature measuring device reaches around 10 ° C. during the defrosting operation. In addition, when the maximum defrosting operation time is provided and the measurement temperature of the outdoor heat exchange temperature measuring device does not rise for approximately 10 to 15 minutes or more, the defrosting is forcibly terminated to prevent the indoor temperature from decreasing. And return to normal heating operation.

When the room temperature reaches the set temperature and the compressor is stopped, the indoor fan is stopped to prevent cold air. When the room temperature falls below the set temperature and the compressor starts to operate again, confirm that the indoor heat exchanger has warmed up based on the temperature measured by the indoor heat exchanger (about 25 ° C) and then operate the indoor fan. (Hereinafter, this operation control will be referred to as hot keep operation). There are models that do not stop the indoor fan even when the compressor is stopped. However, in order to prevent the user from feeling cold, the model that extremely reduces the rotational speed of the indoor fan and the model that fixes the louver direction upward. Is also present.
JP 7-229662 A

The low temperature operation is an operation aimed at heating the air conditioner and preventing the room from freezing in a cold outside air environment to the extent that the room is frozen, so the set temperature is about 10 ° C. good. When such an operation is performed with normal heating operation specifications, the following problems occur.
First, in low temperature operation, the room temperature reaches the set temperature and the compressor is likely to stop, and it is easy to shift to hot keep operation. However, in hot keep operation, the indoor fan stops, so the indoor temperature distribution is not uniform. . As a matter of course, the temperature is lowered as the floor surface is approached, and the freezing temperature is likely to be 0 ° C. However, since the indoor unit of the air conditioner is installed above, it is difficult to obtain temperature information of the floor surface, and it is not possible to cope with the excessively low temperature of the floor surface.

Further, the frequency of the inverter that drives the compressor is lowered without stopping until the compressor is stopped, and even when the indoor fan is operated with a slight wind, the hot air does not always reach from the indoor unit to a distant place.
Also, when defrosting, the frost of the outdoor heat exchanger is melted by the heat stored in the indoor heat exchanger and the condensation heat generated when the refrigerant is compressed by the compressor, but the set temperature is originally low. Therefore, the operation time of the compressor is short. Therefore, the temperature of the indoor heat exchanger tends to be low, and since the amount of heat that can be used for defrosting is smaller than usual, the time required for defrosting becomes longer. Therefore, when the defrosting operation is started, it is necessary to surely defrost, but since the maximum defrosting operation time is provided, the defrosting may end halfway and frost may remain.

Patent Document 1 describes a defrosting operation control device for an air conditioner that switches the start of the defrosting operation of the outdoor heat exchanger during heating operation according to the operating state of the compressor.
The present invention has been made in view of the above-described circumstances, and can reliably perform a low-temperature operation in which heating is performed at a temperature that is lower than a comfortable temperature and does not freeze in the cold season, and a defrosting operation at a low-temperature operation. An object is to provide an air conditioner.

In order to solve the above problems, the indoor fan is operated even when the compressor is stopped. When the rotation speed of the indoor fan is equal to or higher than the predetermined rotation speed, the indoor fan is conventionally based on the temperature of the indoor heat exchanger. However, when the rotational speed is less than the predetermined rotational speed, control is adopted that does not decrease the rotational speed of the indoor fan. As a result, the wind reaches the floor and far away to prevent freezing in the room, and the temperature distribution difference in the room is reduced, thereby obtaining a more accurate room temperature.
Further, basically, the defrosting operation is terminated based on the temperature of the outdoor heat exchanger, so that the defrosting can be surely performed, and the iced state of the outdoor heat exchanger due to insufficient defrosting is avoided.

Moreover, the continuous defrosting time is limited and the defrosting is continued further to avoid freezing the room during the defrosting operation.
Moreover, defrost control is completed in a short time by providing the defrost preparation mode. In addition, by setting a wide range for the set temperature, it is possible to avoid freezing by raising the room temperature even in areas where there is a possibility of freezing depending on the installation area. Can be prevented.
In addition, by moving the louver, it is possible to send wind to every corner.

  An air conditioner according to the present invention includes an outdoor heat exchanger provided outdoors, an indoor heat exchanger provided indoors, and an outdoor heat exchanger that measures the temperatures of the outdoor heat exchanger and the indoor heat exchanger. A temperature measuring device, an indoor heat exchanger temperature measuring device, an indoor fan for blowing out the air heat-exchanged by the indoor heat exchanger into the room, an indoor temperature measuring device for measuring the temperature of the indoor air, the outdoor heat exchanger, A compressor that compresses the refrigerant flowing through the indoor heat exchanger and flows through the corresponding paths for the cooling operation and the heating operation, and a frost detection unit that detects frost formation on the outdoor heat exchanger, In the air conditioner configured to defrost when detected by the frost detection means, an instruction to execute a low temperature operation for heating at a set temperature that is lower than the comfortable temperature and does not freeze in the cold season is received. Reception means and execution of the low temperature operation Means for continuing the operation of the indoor fan regardless of the stop of the compressor and the temperature measured by the indoor heat exchange temperature measuring device, and stopping the indoor fan when defrosting during the low temperature operation. When defrosting during execution of the low temperature operation, the defrosting is performed until the measured temperature of the outdoor heat exchanger temperature measuring device reaches a predetermined temperature.

  In this air conditioner, an outdoor heat exchanger is provided outdoors, an indoor heat exchanger is provided indoors, and an outdoor heat exchanger temperature measuring device and an indoor heat exchanger temperature measuring device are an outdoor heat exchanger and an indoor heat exchanger. Measure the temperature of each. The indoor fan blows out the air heat-exchanged by the indoor heat exchanger into the room, and the indoor temperature measuring device measures the temperature of the indoor air. The compressor compresses the refrigerant flowing through the outdoor heat exchanger and the indoor heat exchanger, and causes the refrigerant to flow through the respective paths corresponding to the cooling operation and the heating operation, and the frosting detection unit forms frosting on the outdoor heat exchanger. Is detected, and when the frost detection means detects, defrosting is performed. The reception means receives an instruction to execute a low-temperature operation in which heating is performed at a set temperature that is lower than the comfortable temperature and does not freeze in the cold season, and during the low-temperature operation, the compressor is stopped and the temperature measured by the indoor heat exchanger is measured. Regardless of the operation of the indoor fan, when the defrosting is performed during the low temperature operation, the indoor fan is stopped. When defrosting during execution of the low temperature operation, defrosting is performed until the temperature measured by the outdoor heat exchange temperature measuring device reaches a predetermined temperature.

  In the air conditioner according to the present invention, when the frost detection means detects, a means for increasing the output of the compressor to a predetermined amount for a predetermined time, and a predetermined number of rotations of the indoor fan for the predetermined time. And a means for reducing the temperature after the predetermined time has elapsed.

  In this air conditioner, when the frost detection means detects, the output of the compressor is increased to a predetermined amount for a predetermined time, and the rotation speed of the indoor fan is decreased to a predetermined rotation time for a predetermined time, and the predetermined time has elapsed. Defrost later.

  The air conditioner according to the present invention is further characterized by further comprising means for changing the set temperature within a predetermined range every predetermined first time around the set temperature.

  The air conditioner according to the present invention is configured to start defrosting during execution of the low-temperature operation and end defrosting when a predetermined second time has elapsed.

  The air conditioner according to the present invention further includes an electric vertical louver that shakes the air blown out by the indoor fan in the vertical direction, and an electric left and right louver that shakes the air in the horizontal direction, and when the receiving unit receives the execution instruction Is configured to start the electric upper and lower louvers and the electric left and right louvers.

  In this air conditioner, when the electric upper and lower louvers swing the air blown by the indoor fan in the vertical direction, the electric left and right louvers shake the air blown by the indoor fan in the left and right directions, and the accepting means accepts the low temperature operation execution instruction The electric up / down louver and the electric left / right louver are started.

  In the air conditioner according to the present invention, during the execution of the low temperature operation, the rotation speed of the indoor fan is set to a predetermined first rotation speed or a predetermined first rotation speed higher than the first rotation speed every predetermined third time. It is configured to be switched to two revolutions.

  In this air conditioner, during the low temperature operation, the rotation speed of the indoor fan is switched to a predetermined first rotation speed or a predetermined second rotation speed higher than the first rotation speed every predetermined third time.

According to the air conditioner according to the present invention, it is possible to realize an air conditioner that can reliably perform a low-temperature operation in which heating is performed at a temperature that is lower than a comfortable temperature in the cold season and the room is not frozen, and a defrosting operation in the low-temperature operation. Can do. Further, it is possible to continue the low temperature operation safely.
In normal heating operation, at a set temperature of 10 ° C., as the frequency of the inverter that drives the compressor motor first decreases, the rotational speed of the indoor fan also decreases, so there is a possibility that the wind will not reach every corner of the room. is there. When the compressor is stopped (when the room temperature is likely to exceed the set temperature), the indoor fan stops to prevent cold air, so there is a risk of freezing from the floor. There is a possibility of being late.

According to the air conditioner according to the present invention, it is possible to realize an air conditioner that can reliably perform a low-temperature operation in which heating is performed at a temperature that is lower than a comfortable temperature in the cold season and the room is not frozen, and a defrosting operation in the low-temperature operation. Can do.
During defrosting during low-temperature operation, the set temperature may be low and heat is not stored in the indoor heat exchanger, so the defrosting time tends to be longer. The defrosting can be completed more quickly by executing a preparatory operation for preparing to be executed.

  According to the air conditioner according to the present invention, it is possible to realize an air conditioner that can reliably perform a low-temperature operation in which heating is performed at a temperature that is lower than a comfortable temperature in the cold season and the room is not frozen, and a defrosting operation in the low-temperature operation. Can do. Moreover, freezing of the room can be prevented more safely and reliably by changing the set temperature.

  According to the air conditioner according to the present invention, it is possible to realize an air conditioner that can reliably perform a low-temperature operation in which heating is performed at a temperature that is lower than a comfortable temperature in the cold season and the room is not frozen, and a defrosting operation in the low-temperature operation. Can do. Moreover, the effect which suppresses indoor freezing can be anticipated by providing the time limit for continuous operation of defrosting.

  According to the air conditioner according to the present invention, it is possible to realize an air conditioner that can reliably perform a low-temperature operation in which heating is performed at a temperature that is lower than a comfortable temperature in the cold season and the room is not frozen, and a defrosting operation in the low-temperature operation. Can do. Further, by swinging the electric upper and lower louvers and the electric left and right louvers, the wind can be sent to every corner of the room.

  According to the air conditioner according to the present invention, it is possible to realize an air conditioner that can reliably perform a low-temperature operation in which heating is performed at a temperature that is lower than a comfortable temperature in the cold season and the room is not frozen, and a defrosting operation in the low-temperature operation. Can do. Even if the indoor air cannot be agitated due to the operation of the indoor fan at a low speed, the indoor air can be agitated to every corner by periodically operating the indoor fan at a high speed for a predetermined time. Therefore, freezing can be prevented in every corner of the room at low power cost.

Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof.
FIG. 1 is a cross-sectional view schematically showing a configuration of an embodiment of an air conditioner according to the present invention. This air conditioner is a separate type, installed above the wall in the house 15, and installed on the ground along the outer wall of the house 15 and the indoor unit 7 that blows the hot air 16 downward in the heating operation. And an outdoor unit 14. In the indoor unit 7, a control device 20 including a microcomputer that controls each device provided in the indoor unit 7 and the outdoor unit 14 is provided.

  FIG. 2 is a perspective view showing the appearance of the indoor unit 7. As shown in the side longitudinal sectional view of FIG. 3, the indoor unit 7 shuts off the indoor temperature measuring device 1 that measures the temperature of the air sucked from the room, and the air inlet from the room and the air outlet to the room. The indoor heat exchanger 3 for exchanging heat with the sucked air and the indoor heat exchanger temperature measuring device 2 for measuring the temperature of the indoor heat exchanger 3 are provided.

  The indoor unit 7 is also provided at the blowout port side of the indoor unit 7 in the indoor heat exchanger 3, and is provided at the blowout port with the sirocco indoor fan 4 that blows out the heat-exchanged air from the blowout port. The electric up-and-down louver 5 which shakes the air to be blown up and down, and the electric left and right louver 6 which is provided at the outlet and shakes the blown-out air in the left and right direction. Further, although a control unit having a microcomputer for controlling each of the above devices, an operation lamp, and the like are provided, the illustration is omitted. Note that the louver can be operated at a low temperature even with a non-electric model.

  FIG. 4 is a perspective view showing the appearance of the outdoor unit 14. As shown in the exploded schematic diagram of FIG. 5, the outdoor unit 14 is provided so as to block the outside air temperature measuring device 12 that measures the temperature of the sucked outside air, and the outside air inlet and the outdoor outlet, An outdoor heat exchanger 8 that exchanges heat with the sucked outside air and an outdoor heat exchanger temperature measuring device 13 that measures the temperature of the outdoor heat exchanger 8 are provided.

  The outdoor unit 14 is also provided on the outlet side of the outdoor unit 14 of the outdoor heat exchanger 8, and the outdoor fan 9, the indoor heat exchanger 3, and the outdoor heat exchanger that blow out the heat-exchanged outside air from the outlet. The compressor 11 which compresses the refrigerant | coolant which flows in the piping which does not illustrate connecting the 8 and the four-way valve 10 which switches the direction through which the refrigerant | coolant which the compressor 11 compressed flows according to the time of cooling or heating is provided. Moreover, although the expansion valve and capillary tube peculiar to the outdoor unit 14 are also provided, illustration is abbreviate | omitted.

FIG. 6 is a piping system diagram showing the refrigeration cycle of the air conditioner according to the present invention, and shows each flow path of the refrigerant during the heating operation (a) and during the defrosting operation (b).
In this refrigeration cycle, during the heating operation (a), the four-way valve 10 and the three-way valve 18 in which the gaseous refrigerant compressed to the high temperature and high pressure by the rotary compressor 11 being compressed by the outdoor unit 14 is switched to the heating operation. Is sent to the indoor heat exchanger 3 of the indoor unit 7. The high-temperature and high-pressure refrigerant sent to the indoor heat exchanger 3 loses heat (condensation heat) to the indoor air passing through the indoor heat exchanger 3 by the indoor fan 4 and condenses and liquefies, and the temperature of the indoor air rises. To do.

  The liquefied refrigerant is sent to the outdoor heat exchanger 8 via the two-way valve 17 and the capillary tube (capillary tube) 19 of the outdoor unit 14, and the pressure is reduced during that time. The decompressed refrigerant is supplied to the outside air passing through the outdoor heat exchanger 8 by the outdoor fan 9 to be vaporized by being supplied with heat of vaporization, and then returned to the compressor 11 via the four-way valve 10. The gaseous refrigerant returned to the compressor 11 is compressed again to a high temperature and high pressure, and is sent to the indoor heat exchanger 3 of the indoor unit 7 via the four-way valve 10 and the three-way valve 18.

  During the defrosting operation (b), this refrigeration cycle is operated in the same way as during the cooling operation, and the gaseous refrigerant compressed to high temperature and high pressure by the rotary compressor 11 in the outdoor unit 14 is used for the defrosting operation. It is sent to the outdoor heat exchanger 8 via the four-way valve 10 that has been switched to (for cooling operation). The high-temperature and high-pressure refrigerant sent to the outdoor heat exchanger 8 is condensed and liquefied by the outdoor fan 9 taking heat (condensation heat) from the outside air passing through the outdoor heat exchanger 8.

  The liquefied refrigerant is sent to the indoor heat exchanger 3 of the indoor unit 7 via the capillary tube (capillary tube) 19 and the two-way valve 17, and the refrigerant is depressurized during that time. The decompressed refrigerant is supplied with vaporization heat to the indoor air passing through the indoor heat exchanger 3 by the indoor fan 4 and vaporized, and then returned to the compressor 11 via the three-way valve 18. Here, the temperature of the indoor air to which the heat of vaporization is supplied is lowered. The gaseous refrigerant returned to the compressor 11 is compressed again to a high temperature and high pressure and sent to the outdoor heat exchanger 8.

Below, operation | movement of the air conditioner of such a structure is demonstrated, referring the flowchart of FIG.7,8,9 which shows it.
The air conditioner control device 20 performs a cooling operation or a heating operation as usual in accordance with an operation of a remote control device (not shown). When the low temperature button provided in the remote control device is operated, the low temperature operation is started.
The low-temperature operation is intended to prevent indoor freezing in a cold region, and usually no consideration is given to people, such as the prevention of cold wind, assuming that there are no people in the room. Also, compared to using an oil fan heater or the like, the safety is expected to increase because no fire is used.

  When the low temperature button is operated, the control device 20 first sets the room temperature to 10 ° C. (S1), and then determines whether the room temperature measured by the room temperature measuring device 1 is less than 10 ° C. ( S3) If it is less than 10 ° C., the compressor 11, the outdoor fan 9 and the indoor fan 4 are activated, and the heating operation is started at the set temperature of 10 ° C. (S5). During this heating operation, the electric up / down louver 5 is swung in the up / down direction, and the electric left / right louver 6 is swung in the left / right direction.

The control device 20 sets the set temperature of the room temperature to 10 ° C. (S1), and then sets the set temperature within a predetermined range (for example, 2 ° C.) every predetermined time (for example, 1 hour) centering on 10 ° C. It is also possible to change in the order of 10 ° C. → 12 ° C. → 10 ° C. → 8 ° C. → 10 ° C. →. Thus, freezing of a room can be prevented more reliably by changing the set temperature.
It is also possible to switch the rotation speed of the indoor fan 4 to a normal rotation speed or a predetermined rotation speed higher than the normal rotation speed every predetermined time (for example, 10 minutes). As a result, even when the indoor air cannot be completely agitated during the operation of the indoor fan 4 at the normal rotation speed, the indoor fan 4 is periodically operated at a higher rotation speed than the normal time for a predetermined time. Since the agitation can be performed as much as possible, freezing can be prevented at every corner of the room at low power cost.

  The control device 20 determines whether or not the room temperature measured by the room temperature measuring instrument 1 has become 10 ° C. or higher during the heating operation (S7). The frequency of the inverter to drive is reduced, and the output of the compressor 11 is reduced by a predetermined amount (S9). Moreover, after reducing the rotation speed of the indoor fan 4 to a predetermined rotation speed (S11), it is determined whether or not the room temperature measured by the room temperature measuring instrument 1 is less than 10 ° C. (S3).

The control device 20 determines whether or not the room temperature measured by the room temperature measuring instrument 1 has become 10 ° C. or higher during the heating operation (S7), and if it has not exceeded 10 ° C., outdoor heat exchange. It is determined whether frosting of the container 8 is detected (S21). If frost formation is not detected, it is determined again whether or not the room temperature measured by the room temperature measuring instrument 1 has become 10 ° C. or higher (S7).
If the control apparatus 20 has detected the frost formation of the outdoor heat exchanger 8 (S21), after performing a defrost operation (S23), the room temperature which the room temperature measuring device 1 measured is less than 10 degreeC. It is determined whether or not (S3).

If the room temperature measured by the room temperature measuring device 1 is not less than 10 ° C. (S3), the control device 20 determines whether or not frost formation in the outdoor heat exchanger 8 is detected (S13), and frost formation is performed. If the defrosting operation is executed (S23), it is determined whether or not the room temperature measured by the room temperature measuring device 1 is less than 10 ° C. (S3).
If the frosting of the outdoor heat exchanger 8 is not detected (S13), the control device 20 determines whether or not the room temperature measured by the room temperature measuring device 1 is 11 ° C. or more (S15). If the temperature is not 11 ° C. or higher, it is determined again whether or not the room temperature measured by the room temperature measuring instrument 1 is less than 10 ° C. (S3).

  If the room temperature measured by the room temperature measuring device 1 is 11 ° C. or higher (S15), the control device 20 stops the compressor 11 (S17) and maintains the rotational speed of the indoor fan 4 at a predetermined rotational speed. (S19), it is determined whether the room temperature measured by the room temperature measuring instrument 1 is less than 10 ° C. (S3). If the room temperature is not 11 ° C. or higher (S15), it is determined whether the room temperature measured by the room temperature measuring instrument 1 is less than 10 ° C. (S3).

The detection of frost formation in the outdoor heat exchanger 8 is performed by the fact that the measured temperature of the outdoor heat exchanger temperature measuring device 13 is suddenly lowered or the difference between the outdoor air temperature and the measured temperature of the outdoor heat exchanger temperature measuring device 13 is thereby detected. Judgment is made based on a rapid change or the like.
Normally, when the output of the compressor 11 decreases and the temperature of the indoor heat exchanger 3 decreases, in order to maintain the blowing temperature as much as possible, the rotational speed of the indoor fan 4 is also reduced, and the compressor 11 is stopped. In this case, the indoor fan 4 is also stopped. However, in the low temperature operation, even if the temperature of the indoor heat exchanger 3 decreases, the rotational speed of the indoor fan 4 is not lowered below a predetermined rotational speed, and even if the compressor 11 stops, the rotational speed of the indoor fan 4 is reduced. Maintain a predetermined number of revolutions.

This is because when the indoor fan 4 is stopped, the room usually cools from the floor surface, but the indoor temperature measuring instrument 1 of the air conditioner mounted above can grasp the condition of the floor surface. It is not possible. Further, since the purpose is to prevent indoor freezing, it is necessary to keep the floor surface and every corner of the room at 0 ° C. or higher.
According to the results of the examination by the inventors in the laboratory, it has been found that if the set temperature is maintained at 10 ° C., the room is hardly frozen. However, in an actual user's house, it is impossible to grasp all the conditions of driving, so it is possible to freeze more reliably by changing the set temperature in the range of 9 ° C to 14 ° C. A prevention function can be provided. The method for changing the set temperature is only required to be periodically raised or lowered. Note that it is possible to change the set temperature with a remote control device or the like, so that the set temperature is not changed, or it can be maintained at a higher temperature.

  When executing the defrosting operation (S23), the controller 20 may determine whether or not the compressor 11 is in operation (S31 in FIG. 8). Otherwise, the operation of the compressor 11 is started (S63). Next, the rotational speed of the indoor fan 4 is reduced to a predetermined rotational speed (S33), the electric upper and lower louvers 5 are fixed upward (S35), and the timer count is started (S37), and then the output of the compressor 11 is increased. (S39) to enter the defrost preparation mode.

In the defrost preparation mode, the control device 20 prohibits changing the output of the compressor 11 after increasing the output of the compressor 11 (S39) (S41). When the time is counted for 3 minutes (S43), the timer is reset (S45 in FIG. 9), then defrosting is started (S47), and the time measurement with the timer is started again (S49).
When the defrosting is started (S47), the control device 20 stops the indoor fan 4, the outdoor fan 9, and the compressor 11, and then switches the four-way valve 10 to operate only the compressor 11 again to defrost.

  After starting defrosting (S47) and timing for 3 minutes (S51), the control device 20 determines whether or not the measured temperature of the outdoor heat exchanger temperature measuring device 13 is 10 ° C. or higher (S53). If it is 10 degreeC or more, a timer will be reset (S55) and a defrost will be complete | finished (S57). When the defrosting is finished, after the compressor 11 is stopped, the operation of the outdoor fan 9 is started, and after the four-way valve 10 is switched and restored (S59), the process returns to resume the low-temperature operation.

  If the measured temperature of the outdoor heat exchanger temperature measuring device 13 is not 10 ° C. or higher (S53), the controller 20 determines whether or not 30 minutes have passed since the start of defrosting (S47) (S61), If 30 minutes have not passed, it is further determined whether or not the measured temperature of the outdoor heat exchanger temperature measuring device 13 is 10 ° C. or higher (S53). Hereinafter, whether the measurement temperature of the outdoor heat exchanger temperature measuring device 13 is 10 ° C. or higher (S53), or until 30 minutes have passed (S61), whether defrosting is continued and the measured temperature is 10 ° C. or higher (S53) When 30 minutes have elapsed (S61), the timer is reset (S55), and the defrosting is terminated (S57).

When the user leaves the house for a long period of time and the low temperature operation is repeated, the outdoor heat exchanger 8 is frosted. Therefore, when it is detected that frost formation has occurred, the defrost preparation mode is entered, the frequency of the inverter that drives the motor of the compressor 11 is increased, the capacity of the compressor 11 is increased, and the temperature of the indoor heat exchanger 3 is increased. .
Although the defrost preparation mode ends in 3 minutes, the operation of the compressor 11 is continued even if the measured temperature of the room temperature measuring instrument 1 rises to the set temperature (10 ° C.) by the end. Moreover, the rotation speed of the indoor fan 4 is reduced to a predetermined rotation speed, the direction of the electric upper and lower louvers 5 is fixed upward, the short circuit state is established, and heat is stored as much as possible to prepare for defrosting. When 3 minutes have passed, defrosting is started.

The defrosting is started by stopping the indoor fan 4, the outdoor fan 9 and the compressor 11 and switching the four-way valve 10 and then operating only the compressor 11 again. After the operation of the compressor 11 is continued for a minimum of 3 minutes, when the temperature of the outdoor heat exchanger 8 is monitored and reaches 10 ° C., it is determined that the defrosting is finished, and the defrosting operation is finished. Further, if the temperature of the outdoor heat exchanger 8 does not reach 10 ° C. even after 30 minutes have elapsed since the start of the defrosting, the defrosting operation is forcibly terminated.
When the defrosting operation is terminated or forcibly terminated, the operation of the compressor 11 is stopped, the operation of the outdoor fan 9 is started, and the four-way valve 10 is switched to the heating cycle side while reducing the refrigerant pressure difference. Start cold operation again.

It is sectional drawing which shows typically the structure of embodiment of the air conditioner which concerns on this invention. It is a perspective view which shows the external appearance of the indoor unit of the air conditioner which concerns on this invention. It is a side longitudinal section showing an example of important section composition of an indoor unit of an air harmony machine concerning the present invention. It is a perspective view which shows the external appearance of the outdoor unit of the air conditioner which concerns on this invention. It is a disassembled schematic diagram which shows the principal part structural example of the outdoor unit of the air conditioner which concerns on this invention. It is a piping system diagram which shows the refrigerating cycle of the air conditioner which concerns on this invention. It is a flowchart which shows operation | movement of the air conditioner which concerns on this invention. It is a flowchart which shows operation | movement of the air conditioner which concerns on this invention. It is a flowchart which shows operation | movement of the air conditioner which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Indoor temperature measuring device 2 Indoor heat exchanger temperature measuring device 3 Indoor heat exchanger 4 Indoor fan 5 Electric upper / lower louver 6 Electric left / right louver 7 Indoor unit 8 Outdoor heat exchanger 9 Outdoor fan 10 Four-way valve 11 Compressor 12 Outside air temperature measuring device 13 Outdoor heat exchange temperature measuring device (defrost thermo)
14 Outdoor unit 15 House 16 Hot air 17 Two-way valve 18 Three-way valve 19 Capillary tube (capillary tube)
20 Control device

Claims (6)

An outdoor heat exchanger provided outdoors, an indoor heat exchanger provided indoors, an outdoor heat exchanger temperature measuring device and an indoor heat exchanger temperature measurement for measuring temperatures of the outdoor heat exchanger and the indoor heat exchanger, respectively. , An indoor fan that blows out the air heat-exchanged by the indoor heat exchanger into the room, an indoor temperature measuring device that measures the temperature of the indoor air, and a refrigerant that flows through the outdoor heat exchanger and the indoor heat exchanger And a frosting detection means for detecting frost formation on the outdoor heat exchanger, when the frost detection means detects In the air conditioner configured to defrost,
Receiving means for receiving a low temperature operation execution instruction that heats at a set temperature that is lower than a comfortable temperature and does not freeze in the cold season; and during the low temperature operation, the compressor is stopped and the indoor heat exchanger temperature measuring device Regardless of the measured temperature, when the indoor fan continues to operate and defrosts during the low-temperature operation, the indoor fan is stopped and defrosted during the low-temperature operation. Is configured to defrost until the temperature measured by the outdoor heat exchanger temperature measuring device reaches a predetermined temperature.   Means for increasing the output of the compressor to a predetermined amount for a predetermined time when the frost detection means detects, and means for reducing the rotational speed of the indoor fan to a predetermined rotational speed for the predetermined time; The air conditioner according to claim 1, wherein the air conditioner is configured to be defrosted after the predetermined time has elapsed.   The air conditioner according to claim 1 or 2, further comprising means for changing the set temperature within a predetermined range at predetermined first times with the set temperature as a center.   The air conditioning according to any one of claims 1 to 3, wherein defrosting is started during execution of the low temperature operation and the defrosting is terminated when a predetermined second time has elapsed. Machine.   An electric upper and lower louver that shakes the air blown by the indoor fan in the vertical direction; and an electric left and right louver that shakes the air in the left and right direction, and when the receiving means receives the execution instruction, the electric vertical louver and the electric left and right louvers The air conditioner according to any one of claims 1 to 4, wherein the louver is configured to start.   During execution of the low temperature operation, the rotational speed of the indoor fan is switched to a predetermined first rotational speed or a predetermined second rotational speed higher than the first rotational speed every predetermined third time. The air conditioner according to any one of claims 1 to 5.

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