WO2014126046A1

WO2014126046A1 - Air conditioner

Info

Publication number: WO2014126046A1
Application number: PCT/JP2014/053050
Authority: WO
Inventors: 藤本知
Original assignee: シャープ株式会社
Priority date: 2013-02-12
Filing date: 2014-02-10
Publication date: 2014-08-21
Also published as: JP2014153008A; JP6185251B2; CN104969010B; CN104969010A

Abstract

An air conditioner is provided with: a control device (10) which controls the rotational speed of a compressor (1) according to air conditioning operation and which controls the drive of an indoor fan (7) according to the rotational speed of the compressor (1); a temperature detector (14) which detects the temperature of an indoor heat exchanger (6); and a humidity detector (13) which detects indoor humidity. When performing dehumidification operation, the control device (10) performs correction control which, in order that the temperature of the indoor heat exchanger (6) is the dew point temperature at which humidity is lower than the detected indoor humidity, reduces the air blowing capacity of the indoor fan (7) by reducing the rotational speed thereof. Consequently, the temperature of the indoor heat exchanger is reduced while the dehumidification capacity is maintained, and as a result, dehumidification is capable of being performed while minimizing a reduction in indoor temperature.

Description

Air conditioner

The present invention relates to an air conditioner that performs an energy-saving dehumidifying operation.

In the air conditioner, when the dehumidifying operation is performed, the indoor air is condensed by the indoor heat exchanger, and the dry air is blown out into the room. As the dehumidifying operation, a weak operation of the cooling operation is performed. In this operation, the humidity decreases, but the room temperature also decreases, which may give the user a feeling of cold air.

In order to prevent a decrease in room temperature during the dehumidifying operation, in Patent Document 1, the rotation of the compressor with a variable number of revolutions is set to a lower speed than in the normal cooling operation, and the rotation of the indoor fan is also reduced. Thereby, dehumidification is performed while preventing a decrease in room temperature.

JP 59-185932 A

In the case of the above dehumidifying operation, if the rotational speed of the compressor is lowered to the minimum rotational speed during the dehumidifying operation, the dehumidifying capacity is lowered and the temperature of the indoor heat exchanger cannot be lowered. If the temperature of the indoor heat exchanger does not fall to the desired humidity dew point, moisture in the room air cannot be condensed. As a result, the room temperature decreases, but a situation in which dehumidification cannot be performed occurs.

In view of the above, an object of the present invention is to provide an air conditioner that can perform dehumidification while suppressing a decrease in room temperature by lowering the temperature of an indoor heat exchanger while maintaining dehumidification capability.

The air conditioner of the present invention includes an indoor fan in which a refrigeration cycle is formed from a compressor, an outdoor heat exchanger, a throttle device, and an indoor heat exchanger, and sends indoor air to the indoor heat exchanger, and a compressor according to an air conditioning operation. And a control device that drives and controls the indoor fan in accordance with the rotational speed of the compressor. A temperature detector that detects the temperature of the indoor heat exchanger and a humidity detector that detects the humidity of the room are provided, and the controller detects the indoor humidity at which the temperature of the indoor heat exchanger is detected during the dehumidifying operation. Correction control is performed to reduce the blowing capacity of the indoor fan so that the dew point temperature has a lower humidity.

When performing the dehumidifying operation, by reducing the blowing capacity of the indoor fan, the temperature of the indoor heat exchanger can be easily lowered, and the amount of cold air blown into the room can be reduced. Thereby, sensible heat cooling capability becomes low and the fall of room temperature can be suppressed. And the indoor humidity becomes the target humidity when the temperature of the indoor heat exchanger becomes a dew point temperature lower than the dew point temperature of the detected indoor humidity.

The indoor fan is driven at a reference rotational speed corresponding to the rotational speed of the compressor, and during the dehumidifying operation, the control device sets the rotational speed of the indoor fan to a rotational speed lower than the reference rotational speed and adjusts to the temperature of the indoor heat exchanger. Accordingly, the rotation speed of the indoor fan may be changed. When the number of rotations of the indoor fan is reduced, the amount of air passing through the indoor heat exchanger is reduced, so that the air blowing capability is reduced. And by changing the rotation speed of an indoor fan, the temperature of an indoor heat exchanger can be maintained at the dew point temperature of the target humidity, and desired dehumidification can be performed.
Note that the control device may control the indoor fan so that the rotation speed of the indoor fan does not become less than the minimum rotation speed. That is, during the dehumidifying operation, the indoor fan is driven at a minimum rotational speed or more. Thereby, it can avoid that rotation speed of an indoor fan becomes lower than minimum rotation speed, and rotation becomes unstable.

The control device performs correction control of the indoor fan rotation speed when the rotation speed of the compressor is equal to or less than the predetermined rotation speed, and does not perform correction control when the rotation speed of the compressor is greater than the predetermined rotation speed. Good. When the rotation speed of the compressor is larger than the predetermined rotation speed, the temperature of the indoor heat exchanger may be lower than the dew point temperature. If correction control is performed when the temperature of the indoor heat exchanger is lower than the dew point temperature, the temperature of the indoor heat exchanger may further decrease and the indoor heat exchanger may freeze. Therefore, it is possible to dehumidify without lowering the temperature of the indoor heat exchanger, and there is no need to perform correction control.

The control device may change the rotation speed of the indoor fan while maintaining the correction value of the rotation speed of the indoor fan before the change when changing the reference rotation speed in accordance with the change in the rotation speed of the compressor. . Although the reference rotation speed of the indoor fan changes with the change in the rotation speed of the compressor, the dehumidification capability can be maintained by making the correction value for the rotation speed of the indoor fan the same before and after the change.

A lower limit temperature lower than the dew point temperature is set, and the control device performs correction control when the temperature of the indoor heat exchanger is higher than the lower limit temperature, and performs correction control when the temperature of the indoor heat exchanger is equal to or lower than the lower limit temperature. It may not be possible. If the temperature of the indoor heat exchanger is too low, the indoor heat exchanger may be frozen. In order to prevent this freezing, a lower limit temperature is set to the temperature of the indoor heat exchanger. When the temperature of the indoor heat exchanger becomes equal to or lower than the lower limit temperature, the indoor fan is controlled so as to increase the rotation speed of the indoor fan. Thereby, the temperature of an indoor heat exchanger rises and it can prevent freezing beforehand.

If the temperature of the indoor heat exchanger becomes lower than the lower limit temperature, the indoor heat exchanger may be frozen, and if it is frozen, the dehumidifying capacity will decrease. Therefore, when the temperature of the indoor heat exchanger becomes equal to or lower than the lower limit temperature, the temperature of the indoor heat exchanger is increased by increasing the rotation speed of the indoor fan, thereby preventing freezing. Moreover, when the temperature of the indoor heat exchanger becomes lower than the lower limit temperature, the rotational speed of the compressor may be lowered. Thereby, although the fall of the temperature of an indoor heat exchanger is suppressed, a dehumidification capability falls. However, by not performing the correction control, the number of rotations of the indoor fan increases, so that the temperature of the indoor heat exchanger increases. When the temperature of the indoor heat exchanger rises from the lower limit temperature to a certain temperature or more, correction control is performed again, the rotational speed of the indoor fan is lowered, and the dehumidifying capacity is restored.

When a louver for controlling the blowing direction is provided and the blowing capacity of the indoor fan is reduced, the control device may operate the louver to change the blowing direction. Thereby, it is possible to make it difficult for the user to directly hit the cold air, and it is possible to provide the user with a comfortable space maintained at a constant temperature.

According to the present invention, by reducing the rotational speed of the indoor fan, the temperature of the indoor heat exchanger can be lowered to the target humidity dew point temperature even when the rotational speed of the compressor is low, without lowering the room temperature. Can be dehumidified. In addition, the power consumption of the indoor fan can be reduced, the evaporation temperature of the refrigeration cycle can be lowered, and an energy-saving dehumidifying operation can be realized.

Schematic configuration diagram of the refrigeration cycle of the air conditioner of the present invention Air conditioner control device block diagram The figure which shows the change of the rotation speed of an indoor fan with respect to the temperature of an indoor heat exchanger The figure which shows the change of the rotation speed of an indoor fan when the temperature of an indoor heat exchanger becomes an operation | movement minimum temperature.

The air conditioner of this embodiment is shown in FIG. This air conditioner is configured by connecting an outdoor unit and an indoor unit by piping and wiring. The outdoor unit includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an expansion device 4, and an outdoor fan 5. The indoor unit includes an indoor heat exchanger 6 and an indoor fan 7. A refrigeration cycle is formed by the compressor 1, the four-way valve 2, the outdoor heat exchanger 3, the expansion device 4, and the indoor heat exchanger 6. Although the expansion valve is used as the expansion device 4, a capillary tube or the like may be used.

As shown in FIG. 2, the air conditioner includes a control device 10 that controls the refrigeration cycle and performs air conditioning operations such as cooling, heating, and dehumidification. An outdoor air temperature detector 11 is provided in the outdoor unit, and a room temperature detector 12 and a humidity detector 13 are provided in the indoor unit. Moreover, the indoor heat exchanger temperature detector 14 which detects the temperature of the indoor heat exchanger 6 is provided. The control device 10 rotates the compressor 1 based on the temperature and humidity detected by the

temperature detectors

11, 12, 14 and the humidity detector 13 according to the designated air conditioning operation, and the opening degree of the expansion device 4. The rotation of the outdoor fan 5 and the rotation of the indoor fan 7 are controlled.

Here, the control device 10 determines the rotational speed of the compressor 1 based on the set temperature set by the user or the preset temperature set in the automatic operation mode, the detected room temperature, and the outside air temperature. Then, the rotational speed of the indoor fan 7 is determined in accordance with the rotational speed of the compressor 1. The control device 10 controls the compressor 1 at a determined rotational speed, changes the rotational speed of the compressor 1 in accordance with the room temperature, and based on the rotational speed in accordance with the rotational speed of the compressor 1, the indoor fan 7. To control.

The rotational speed of the compressor 1 is set in stages, and the reference rotational speed of the indoor fan 7 is set corresponding to each rotational speed of the compressor 1. This reference rotational speed is also set in stages. For each air conditioning operation such as a cooling operation, a table showing the correspondence between the rotation speeds of the compressor 1 and the indoor fan 7 is stored in the nonvolatile memory. For example, the cooling operation is as follows.

Compressor speed FD1 FD2 FD3 ... FD9
(Rpm) 400 1175 1950 4600
Fan speed during cooling operation F3 F4 F5 ・・・・・ F8
(Rpm) 800 850 930 1110

During cooling operation, when the rotation speed of the compressor 1 is FD1 (400 rpm), the reference rotation speed of the indoor fan 7 is F3 (800 rpm), and when the rotation speed of the compressor 1 is FD2 (1175 rpm), the reference of the indoor fan 7 The rotation speed is F4 (850 rpm). During the air conditioning operation, the control device 10 selects an appropriate rotation speed from the table according to the room temperature, the outside air temperature, and the like, and determines the reference rotation speed of the indoor fan 7 according to the rotation speed. In this air conditioner, the number of rotations of the compressor 1 is set in nine stages from FD1 to FD9. The number of rotations of the indoor fan 7 is set in eight stages from F1 to F8. Here, although the compressor 1 and the indoor fan 7 have different rotational speeds, for example, the reference rotational speed at FD5 and the reference rotational speed at FD6 are set to the same F7. The number of stages is reduced. However, the number of stages in the indoor fan 7 may be the same according to the number of stages in the compressor 1, and the number of stages is not limited to nine.

Further, when performing the air conditioning operation, the control device 10 changes the rotational speed of the indoor fan 7 according to the set temperature and room temperature so that the rotational speed of the indoor fan 7 does not exceed the reference rotational speed. Further, the minimum number of rotations is determined so that the rotation of the indoor fan 7 does not become unstable. The minimum rotation speed is, for example, 300 rpm. The minimum number of revolutions is determined based on the specifications of the motor used for the indoor fan 7. The control device 10 changes the rotation speed of the indoor fan 7 at the minimum rotation speed or more so that it does not become less than the minimum rotation speed. That is, the rotation speed of the indoor fan 7 changes between the minimum rotation speed and the reference rotation speed.

In the dehumidifying operation, a weak cooling operation is performed, but correction control is performed to reduce the blowing capacity of the indoor fan 7 as compared to the cooling operation while monitoring the indoor humidity so that the dehumidification can be performed without lowering the room temperature. Is called. That is, the control device 10 sets the rotational speed of the indoor fan 7 to a rotational speed lower than the reference rotational speed so that the temperature of the indoor heat exchanger 6 becomes the dew point temperature of the target humidity lower than the detected indoor humidity. Correction control for changing the rotational speed of the indoor fan 7 in accordance with the temperature of the indoor heat exchanger 6 is performed.

The reference rotational speed of the indoor fan 7 during the dehumidifying operation is set as follows. The control device 10 drives the indoor fan 7 at the set reference rotational speed at the start of the dehumidifying operation. And if the temperature of the indoor heat exchanger 6 changes with dehumidification operation, the control apparatus 10 will change the rotation speed of the indoor fan 7 according to the temperature of the indoor heat exchanger 6 with respect to dew point temperature. When the outside air temperature or the room temperature changes and the rotation speed of the compressor 1 changes, the reference rotation speed of the indoor fan 7 is also changed. The rotation speed of the indoor fan 7 changes between the minimum rotation speed and the reference rotation speed.

Compressor rotational speed FD1 FD2 FD3 ... FD7
(Rpm) 400 1175 1950 ... 3500
Fan speed during dehumidification operation F1 F2 F3 ... F8
(Rpm) 700 750 800... 1110

When the user operates the remote controller to instruct the dehumidifying operation or the dehumidifying operation is performed in the automatic operation mode, the control device 10 first performs a weak cooling operation (weak cooling operation) that is a normal dehumidifying operation. The correction control is executed when a predetermined time, for example, 15 minutes has elapsed since the start of the dehumidifying operation. Room temperature may be high at the start of dehumidifying operation. In the correction control, since the cooling capacity is lower than that in the weak cooling operation, it takes too much time to bring the room temperature close to the set temperature. Therefore, the control device 10 does not perform correction control at the start of the dehumidifying operation, but performs correction control when a predetermined time has elapsed. Even in a normal weak cooling operation, when the temperature of the indoor heat exchanger 6 falls below the dew point temperature, it has a dehumidifying capacity, and therefore can be dehumidified.

When the predetermined time has elapsed, the control device 10 starts correction control for reducing the blowing capacity by lowering the rotational speed of the indoor fan 7. By performing the correction control after a predetermined time has elapsed, dehumidification can be performed without lowering the room temperature that is the set temperature, and the room can be prevented from being overcooled. Therefore, the correction control can be performed after the room temperature reaches the set temperature, and the correction control characteristic that the dehumidification can be performed without lowering the room temperature can be effectively utilized.

The control device 10 reads the current room temperature from the room temperature detector 12 and reads the current room humidity from the humidity detector 13 when performing correction control. Then, the control device 10 sets a target humidity that is a constant value α% lower than the current humidity. The constant value α is a predetermined value (0 to 30%) and is stored in the nonvolatile memory. Furthermore, the control apparatus 10 sets the humidity lower by β%, for example, 5% than the target humidity, as the lower limit humidity.

The control apparatus 10 calculates the dew point temperature DPo of the target humidity from the current room temperature Ta and the target humidity RHo using the following equation.
DPo = −0.0032 × RHo ² + 0.65 × RHo + Ta−35

The calculated dew point temperature is set as the target temperature DPo (α) of the indoor heat exchanger 6. Furthermore, the control device 10 also calculates the dew point temperature of the lower limit humidity. The calculated dew point temperature is set as the lower limit temperature DPo (α + β) of the indoor heat exchanger 6.

In the correction control, the control device 10 controls the rotation of the indoor fan 7 so that the temperature of the indoor heat exchanger 6 is between the target temperature and the lower limit temperature. That is, at the start of the dehumidifying operation, the control device 10 drives the indoor fan 7 at a reference rotational speed that is lower than the reference rotational speed during the cooling operation. Then, the control device 10 determines whether or not to change the rotational speed of the indoor fan 7 at regular intervals according to the detected temperature of the indoor heat exchanger 6, and when changing the speed, changes it by a predetermined rotational speed. For example, the rotation speed is changed in units of 10 rpm at 1 minute intervals. The change width is set in the range of 0 to 30 rpm.

As shown in FIG. 3, when the temperature Texa of the indoor heat exchanger 6 is higher than the target temperature DPo (α), the control device 10 performs control so as to reduce the rotational speed of the indoor fan 7. Thereby, the air volume of the indoor air passing through the indoor heat exchanger 6 decreases, the evaporation amount of the refrigerant passing through the indoor heat exchanger 6 decreases, and the temperature of the indoor heat exchanger 6 decreases. When the temperature Texa of the indoor heat exchanger 6 becomes equal to or lower than the target temperature DPo (α), the control device 10 maintains the rotation speed of the indoor fan 7 without changing it. When the temperature Texa of the indoor heat exchanger 6 becomes equal to or lower than the lower limit temperature DPo (α + β), the control device 10 controls to increase the rotational speed of the indoor fan 7. Thus, the rotation of the indoor fan 7 is controlled so that the temperature of the indoor heat exchanger 6 is between the lower limit temperature and the target temperature.

By preventing the temperature of the indoor heat exchanger 6 from falling below the lower limit temperature, it is possible to prevent the temperature of the indoor heat exchanger 6 from being lowered excessively and freezing the indoor heat exchanger 6. In addition, by setting the lower limit humidity, the humidity can be reduced to a little lower than the target humidity, preventing the room from drying out excessively, and preventing the cooling capacity and the dehumidifying capacity from being excessively reduced due to a decrease in the air volume. it can.

In such correction control, while the rotational speed of the compressor 1 is the same as that during the cooling operation, the indoor fan 7 is driven at a lower rotational speed than during the cooling operation, so that the air volume of the indoor air passing through the indoor heat exchanger 6 is increased. And the evaporation amount of the refrigerant passing through the indoor heat exchanger 6 is reduced. As the amount of heat absorbed by the indoor heat exchanger 6 decreases, the sensible heat cooling capacity decreases, and conversely the latent heat cooling capacity increases. In addition, the amount of cold air blown into the room is reduced, and a decrease in room temperature can be suppressed. In this way, the sensible heat ratio of the refrigeration cycle can be reduced, and the indoor humidity can be reduced while suppressing a decrease in room temperature. Then, by driving the indoor fan 7 at a low rotational speed so that the temperature of the indoor heat exchanger 6 is between the lower limit temperature and the target temperature, the room can be kept at a desired humidity. By such correction control, the power consumption of the indoor fan 7 can be reduced, and an energy-saving dehumidifying operation can be realized.

By the way, when the rotational speed of the indoor fan 7 decreases and becomes lower than the minimum rotational speed, the rotational control becomes unstable. The control device 10 controls the indoor fan 7 so that the rotational speed of the indoor fan 7 is equal to or higher than the minimum rotational speed. For example, even if the temperature of the indoor heat exchanger 6 is higher than the target temperature DPo (α), if the rotational speed of the indoor fan 7 is lowered and becomes lower than the minimum rotational speed, the rotational speed of the indoor fan 7 is the minimum rotational speed. Maintained above.

Also, when the room temperature is low and the indoor humidity is low, the dew point temperature of the target humidity, that is, the target temperature is set low. In this case, if correction control is performed so that the temperature of the indoor heat exchanger 6 becomes the target temperature, there is a possibility that if the temperature of the indoor heat exchanger 6 is slightly lowered, the temperature becomes lower than the operation lower limit temperature, for example, 5 ° C. When the temperature of the indoor heat exchanger 6 becomes lower than the operation lower limit temperature, the control device 10 performs anti-freezing control. That is, the control device 10 performs correction control when the temperature of the indoor heat exchanger 6 is higher than the operation lower limit temperature, and performs freeze prevention control when the temperature of the indoor heat exchanger 6 is equal to or lower than the operation lower limit temperature. Freezing prevention control is performed with priority over correction control. In the freeze prevention control, when the temperature of the indoor heat exchanger 6 becomes equal to or lower than the operation lower limit temperature, the rotation speed of the compressor 1 is lowered. When anti-freezing control is performed, the dehumidifying ability is lost.

Therefore, during the dehumidifying operation, when the temperature of the indoor heat exchanger 6 decreases and approaches the operating lower limit temperature, as shown in FIG. Correction control is performed so as to avoid it. That is, when the temperature of the indoor heat exchanger 6 approaches the operation lower limit temperature, for example, when the temperature becomes 6 ° C. or less, the control device 10 stops the decrease in the rotational speed of the indoor fan 7. Further, when the temperature of the indoor heat exchanger 6 decreases and becomes lower than the operation lower limit temperature (5 ° C.), the control device 10 increases the rotational speed of the indoor fan 7. When the temperature of the indoor heat exchanger 6 rises and becomes higher than 6 ° C., the control device 10 performs correction control while keeping the rotational speed of the indoor fan 7 from decreasing. When the temperature of the indoor heat exchanger 6 reaches 7 ° C. or higher, the control device 10 performs normal correction control that can reduce the rotational speed of the indoor fan 7. Thereby, even if the temperature of the indoor heat exchanger 6 becomes low, the dehumidifying ability can be maintained and the room can be maintained at a desired humidity.

During air conditioning operation, when the room temperature approaches the set temperature, the rotation speed of the compressor 1 decreases. Along with this, the reference rotational speed of the indoor fan 7 also decreases. In the dehumidifying operation, the minimum rotation speed of the compressor 1, for example, 1200 rpm is set so as to ensure the dehumidifying capacity. During the dehumidifying operation, when the rotation speed of the compressor 1 is lowered according to room temperature or the like and becomes lower than the minimum rotation speed, the control device 10 sets the rotation speed of the compressor 1 to the minimum rotation speed and performs correction control.

When the rotation speed of the compressor 1 is FD1 or FD2, these rotation speeds are lower than the minimum rotation speed (1200 rpm). However, the compressor 1 is driven at the minimum rotational speed. At this time, the reference rotation speed of the indoor fan 7 is set to 700 rpm or 750 rpm corresponding to FD1 or FD2.

For example, at the time of correction control, when the rotational speed of the compressor 1 determined by room temperature or the like is FD2, and the indoor fan 7 is driven at 700 rpm, the compressor 1 is actually driven at the minimum rotational speed, The indoor fan 7 is controlled between a minimum rotation speed (300 rpm) and a reference rotation speed (750 rpm).

Here, when the rotation speed of the compressor 1 changes from FD2 to FD1, the compressor 1 is driven with the minimum rotation speed, and the rotation speed of the indoor fan 7 changes to 650 rpm. In this case, the correction value of the rotation speed of the indoor fan 7 is 50 rpm, but the correction value of the rotation speed does not change even if the reference rotation speed of the indoor fan 7 changes.

Thus, the correction value of the rotational speed is maintained before and after the change of the reference rotational speed of the indoor fan 7. That is, when the control device 10 changes the reference rotational speed of the indoor fan 7 in accordance with the change in the rotational speed of the compressor 1, the control device 10 maintains the correction value for the rotational speed of the indoor fan 7 before the change. Change the rotation speed.

When the room temperature reaches the set temperature during the dehumidifying operation, the control device 10 performs thermo-off control for stopping the compressor 1. When the compressor stops, the control device 10 continues driving while maintaining the rotation speed of the indoor fan 7. However, when the indoor humidity is lower than the target humidity, the control device 10 stops the indoor fan 7. After a while since the compressor 1 is stopped, the room temperature becomes higher than the set temperature, so the control device 10 starts the compressor 1. Until a predetermined time, for example, 5 minutes elapses after the compressor 1 is started, the control device 10 does not perform the correction control and drives the indoor fan 7 while maintaining the rotation speed. When a certain time has elapsed, the control device 10 resumes the correction control and changes the rotational speed of the indoor fan 7. When the indoor fan 7 is stopped and the temperature of the indoor heat exchanger 6 when the correction control is resumed is higher than the target temperature, the control device 10 drives the indoor fan 7 at the minimum rotational speed. When the temperature of the indoor heat exchanger 6 is equal to or lower than the target temperature, the control device 10 drives the indoor fan 7 at the reference rotational speed. Thereby, the rotation speed change of the indoor fan 7 by the rapid temperature change of the indoor heat exchanger 6 before the formation of the stable refrigeration cycle after turning off the compressor 1 can be stabilized.

In the dehumidifying operation, when the correction control is started after a predetermined time has elapsed, the temperature of the indoor heat exchanger 6 may be lower than the target temperature. For example, when the rotational speed of the compressor 1 is high, a low-temperature refrigerant flows into the indoor heat exchanger 6, so the temperature of the indoor heat exchanger 6 decreases. In such a case, when it is confirmed that the detected temperature of the indoor heat exchanger 6 is lower than the target temperature, the control device 10 performs the dehumidifying operation without performing the correction control and reducing the blowing capacity. That is, the indoor fan 7 is driven at a reference rotational speed determined according to the rotational speed of the compressor 1. Thereafter, when the temperature of the indoor heat exchanger 6 rises and becomes equal to or higher than the target temperature, the control device 10 performs correction control and controls the indoor fan 7 so as to reduce the rotational speed of the indoor fan 7.

When the temperature of the indoor heat exchanger 6 is lower than the dew point temperature of the target humidity, the dehumidifying operation is performed without reducing the rotation speed of the indoor fan 7, so the temperature of the indoor heat exchanger 6 does not become too low. As a result, anti-freezing control is performed, and it is possible to prevent the dehumidifying ability from being lowered, and it is also possible to prevent dew condensation on the indoor unit due to low temperature wind blowing.

During the dehumidifying operation, correction control for changing the rotational speed of the indoor fan 7 according to the temperature of the indoor heat exchanger 6 is performed. Further, the rotational speed of the indoor fan 7 changes according to the rotation of the compressor 1. In the correction control of the first embodiment, when the rotation speed of the compressor 1 changes, the correction value of the rotation speed of the indoor fan 7 is maintained, and the reference rotation corresponding to the rotation speed of the compressor 1 after the change. The number of rotations is reduced by a correction value from the number. In this case, even if the rotation speed of the indoor fan 7 changes, the dehumidifying ability can be maintained.

Here, as another form (second embodiment) of correction control, when the rotation speed of the compressor 1 changes, the control device 10 does not change the rotation speed of the indoor fan 7. That is, the rotational speed of the indoor fan 7 is the same before and after the change in the rotational speed of the compressor 1. When the rotation speed of the compressor 1 increases, the rotation speed of the indoor fan 7 with respect to the temperature of the indoor heat exchanger 6 decreases relatively. Then, the control apparatus 10 changes the rotation speed of the indoor fan 7 according to the change of the temperature of the indoor heat exchanger 6. FIG. Therefore, the dehumidifying capacity is temporarily increased. On the contrary, when the rotation speed of the compressor 1 decreases, the room temperature is low and the temperature of the indoor heat exchanger 6 is low. At this time, the dehumidifying ability is high. Since the rotational speed of the indoor fan 7 with respect to the temperature of the indoor heat exchanger 6 is relatively increased, it is possible to prevent the temperature of the indoor heat exchanger 6 from rising and the temperature of the indoor heat exchanger 6 from being too low to freeze. .

Furthermore, as another form (third embodiment) of correction control, when the rotation speed of the compressor 1 changes, the control device 10 resets the correction value of the rotation speed of the indoor fan 7. That is, when the rotation speed of the compressor 1 changes, the indoor fan 7 is driven at the reference rotation speed of the indoor fan 7 corresponding to the changed rotation speed. Then, the control apparatus 10 changes the rotation speed of the indoor fan 7 according to the change of the temperature of the indoor heat exchanger 6. FIG. When the rotation speed of the compressor 1 increases, the dehumidifying capacity temporarily decreases, but the indoor heat exchanger 6 can be prevented from freezing. In particular, when the rotational speed of the compressor 1 changes, if the temperature of the indoor heat exchanger 6 is below the lower limit temperature, the dehumidifying capacity is sufficient, so the correction value may be set to 0. A decrease in temperature can be suppressed.

In the above correction control, the air blowing capacity is reduced by lowering the rotational speed of the indoor fan 7. As another form (fourth embodiment) of the reduction in the blowing capacity, the control device 10 drives the indoor fan 7 intermittently.

That is, when performing the correction control, the control device 10 stops the indoor fan 7 when the temperature of the indoor heat exchanger 6 is higher than the target temperature. During this time, the temperature of the indoor heat exchanger 6 decreases and dehumidification is performed. However, since ventilation is not performed, room temperature does not fall. When the temperature of the indoor heat exchanger 6 decreases and becomes equal to or lower than the lower limit temperature, the control device 10 drives the indoor fan 7 at the reference rotational speed. When the temperature of the indoor heat exchanger 6 rises and becomes higher than the target temperature, the control device 10 stops the indoor fan 7. By repeatedly driving and stopping the indoor fan 7, dehumidification can be performed while suppressing a decrease in room temperature. In addition, dehumidification can be performed while saving energy compared to the case where the indoor fan 7 is always driven.

By the way, a louver for controlling the blowing direction is provided at the outlet of the indoor unit. As the louvers, a horizontal louver that changes the wind direction in the vertical direction and a vertical louver that changes the wind direction in the left-right direction are movably provided, and the control device 10 operates each louver to change the blowing direction.

During dehumidification operation, the wind direction is set so that the horizontal louver is moved and the wind blows out horizontally or diagonally upward, so that the user is not directly exposed to cold air. However, since the rotational speed of the indoor fan 7 becomes low, or immediately after the indoor fan 7 is driven intermittently, the rotational speed is low, so that the specific gravity of the blown cold air is heavy and tends to hang down. . For this reason, cold air may reach the vicinity of the user's living position and feel cold. Therefore, the wind direction is changed by moving the horizontal louver so that the blowing direction of the cold air is further upward than obliquely upward. Further, the direction of the vertical louver may be shifted to either the left or right. By moving the horizontal louver and the vertical louver so that the wind does not hit the user, the feeling of cold air can be eliminated and the comfort by dehumidifying operation that does not lower the room temperature can be enhanced. As described above, when the wind direction is further upward or biased in the left-right direction, the indoor unit may be dewed by the cold air blown out at high humidity. The direction of the wind may be automatically changed only when the humidity is below a certain humidity such as 65% or less.

As described above, the air conditioner of the present invention is an indoor fan in which a refrigeration cycle is formed from the compressor 1, the outdoor heat exchanger 3, the expansion device 4, and the indoor heat exchanger 6, and sends indoor air to the indoor heat exchanger 6. 7 and a control device 10 that controls the rotational speed of the compressor 1 according to the air conditioning operation and drives and controls the indoor fan 7 according to the rotational speed of the compressor 1. A temperature detector 14 for detecting the temperature of the indoor heat exchanger 6 and a humidity detector 13 for detecting the humidity of the room are provided. When the controller 10 performs the dehumidifying operation, the temperature of the indoor heat exchanger 6 is Correction control for reducing the blowing capacity of the indoor fan 7 is performed so that the dew point temperature is lower than the detected indoor humidity.

When performing the dehumidifying operation, by reducing the blowing capacity of the indoor fan 7, the efficiency of heat exchange in the indoor heat exchanger 6 is reduced, the temperature of the indoor heat exchanger 6 is easily lowered, and the air is blown into the room. The amount of cold air can also be reduced. Thereby, sensible heat cooling capability becomes low and the fall of room temperature can be suppressed. Then, the temperature of the indoor heat exchanger 6 can be set to a dew point temperature lower than the detected dew point temperature of the indoor humidity, the latent heat cooling capacity is not lowered, and the indoor humidity is maintained while maintaining the current room temperature. Dehumidification can be achieved to achieve the target humidity.

The indoor fan 7 is driven at a reference rotational speed corresponding to the rotational speed of the compressor 1, and the control device 10 sets the rotational speed of the indoor fan 7 to a rotational speed lower than the reference rotational speed during the dehumidifying operation, thereby exchanging indoor heat. The rotational speed of the indoor fan 7 is changed according to the temperature of the vessel 6.

Since the rotational speed of the indoor fan 7 is reduced, the amount of air passing through the indoor heat exchanger 6 is reduced, so that the air blowing capacity is reduced. And when changing the rotation speed of the indoor fan 7 according to the temperature of the indoor heat exchanger 6, if the rotation speed of the indoor fan 7 is lowered | hung, the temperature of the indoor heat exchanger 6 will fall and the rotation speed of the indoor fan 7 will be reduced. If it raises, the temperature of the indoor heat exchanger 6 will rise. Therefore, by increasing or decreasing the rotational speed of the indoor fan 7, the temperature of the indoor heat exchanger 6 can be maintained at the target humidity dew point temperature.

The control device 10 performs correction control when the rotation speed of the compressor 1 is equal to or lower than the predetermined rotation speed, and does not perform correction control when the rotation speed of the compressor 1 is larger than the predetermined rotation speed.

When the rotation speed of the compressor 1 is greater than the predetermined rotation speed, the temperature of the indoor heat exchanger 6 may be lower than the dew point temperature. If correction control is performed when the temperature of the indoor heat exchanger 6 is lower than the dew point temperature, the temperature of the indoor heat exchanger 6 may further decrease and the indoor heat exchanger 6 may freeze. Therefore, when the rotation speed of the compressor 1 is larger than the predetermined rotation speed, dehumidification can be performed without lowering the temperature of the indoor heat exchanger 6. When the compressor 1 is driven at a predetermined speed or less, by performing correction control, the temperature of the indoor heat exchanger 6 can be lowered to the dew point temperature without lowering the room temperature.

When the control device 10 changes the reference rotational speed according to the change in the rotational speed of the compressor 1, the control apparatus 10 changes the rotational speed of the indoor fan 7 while maintaining the correction value of the rotational speed of the indoor fan 7 before the change.

The rotational speed of the compressor 1 changes depending on the room temperature, the outside air temperature, etc., and the reference rotational speed of the indoor fan 7 changes accordingly. For example, when the reference rotational speed of the indoor fan 7 increases, if the correction is made so that the rotational speed of the indoor fan 7 is lowered from the changed reference rotational speed, the rotational speed after the change of the reference rotational speed is higher than the rotational speed before the change. Thus, even if the temperature of the indoor heat exchanger 6 is close to the dew point temperature, the temperature of the indoor heat exchanger 6 may increase, and the dehumidifying ability may decrease. In order to prevent such a situation, the increase / decrease in the rotational speed of the indoor fan 7 before and after the change is reduced by leaving the correction value of the rotational speed as it is before and after the change in the reference rotational speed of the indoor fan 7, and compression. Even if the rotation speed of the machine 1 changes, the dehumidifying ability can be maintained. Moreover, the responsiveness with respect to the rotation speed of the compressor 1 after a change can be made quick, and a dehumidification capability can be maintained.

A lower limit temperature lower than the dew point temperature is set, and the control device 10 performs correction control when the temperature of the indoor heat exchanger 6 is higher than the lower limit temperature, and corrects when the temperature of the indoor heat exchanger 6 is equal to or lower than the lower limit temperature. Do not control.

If the temperature of the indoor heat exchanger 6 is too low, the indoor heat exchanger 6 may be frozen, and when the indoor heat exchanger 6 is frozen, the dehumidifying capacity is lowered. In order to prevent this freezing, a lower limit temperature is set for controlling so as not to decrease the rotation speed of the indoor fan 7. When the temperature of the indoor heat exchanger 6 falls below the lower limit temperature, the indoor fan 7 is controlled so as to increase the rotational speed of the indoor fan 7. Thereby, the temperature of the indoor heat exchanger 6 rises and freezing can be prevented beforehand.

That is, the dew point temperature is set as a target temperature, and a lower limit temperature lower than the target temperature is set. When the temperature of the indoor heat exchanger 6 is lower than the lower limit temperature, the control device 10 increases the rotational speed of the indoor fan 7 When the temperature of the heat exchanger 6 is higher than the target temperature, the rotational speed of the indoor fan 7 is lowered, and when the temperature of the indoor heat exchanger 6 is between the target temperature and the lower limit temperature, the rotational speed of the indoor fan 7 is maintained. To do.

Moreover, in order to perform anti-freezing control as the lower limit temperature, an operation lower limit temperature lower than the above lower limit temperature is set. When the temperature of the indoor heat exchanger 6 becomes lower than the operation lower limit temperature, the rotational speed of the compressor 1 is lowered. Thereby, although the fall of the temperature of the indoor heat exchanger 6 is suppressed, dehumidification capability falls. Therefore, the control device 10 does not perform correction control when the temperature of the indoor heat exchanger 6 is equal to or lower than the lower limit temperature. That is, when the temperature of the indoor heat exchanger 6 is lower than the dew point temperature, the control device 10 controls the indoor fan 7 at the reference rotational speed without performing correction control during the dehumidifying operation. As described above, by not performing the correction control, the rotational speed of the indoor fan 7 is increased, so that the temperature of the indoor heat exchanger 6 is increased. When the temperature of the indoor heat exchanger 6 rises from the lower limit temperature by a certain temperature or more and approaches the dew point temperature, correction control is performed again, the rotational speed of the indoor fan 7 is lowered, and the dehumidifying ability is restored.

The control device 10 does not perform the correction control at the start of the dehumidifying operation, and then performs the dehumidifying operation with the correction control. At the start of the dehumidifying operation, the room temperature may be high, and it is desirable to lower it to the set temperature. Therefore, by performing the dehumidifying operation without performing the correction control, the air blowing capacity is not lowered, and the room temperature can be lowered while dehumidifying. Correction control is performed after a predetermined time has elapsed from the start of the dehumidifying operation or when the room temperature falls to the operation starting temperature set near the set temperature. Thereby, the room temperature can be quickly set to the set temperature, and further dehumidification can be performed without lowering the room temperature from the set temperature.

The control device 10 performs correction control at the minimum rotational speed or more at which the rotation of the indoor fan 7 becomes unstable. When the rotation speed of the indoor fan 7 becomes lower than the minimum rotation speed, the rotation of the indoor fan 7 becomes unstable. To avoid this. The indoor fan 7 is controlled so that the rotational speed of the indoor fan 7 does not become lower than the minimum rotational speed.

The minimum rotational speed of the compressor 1 during the dehumidifying operation is set, and the control device 10 controls the compressor 1 at the minimum rotational speed even when the rotational speed of the compressor 1 is lower than the minimum rotational speed during the dehumidifying operation. To do. When the rotation speed of the compressor 1 is lowered, the dehumidifying ability is also lowered. Therefore, in order to ensure the dehumidifying ability when performing the correction control, the compressor 1 is lowered in accordance with the room temperature, the outside air temperature, and the like, and even when the compressor 1 is lower than the minimum revolution, The number of rotations is the minimum number of rotations. Thereby, the fall of a dehumidification capability can be prevented. Regarding the control of the indoor fan 7, the rotational speed of the indoor fan 7 is determined based on the reference rotational speed corresponding to the rotational speed of the compressor 1 after the change that becomes lower than the minimum rotational speed.

The control device 10 drives the indoor fan 7 intermittently to reduce the blowing capacity. When the indoor fan 7 is intermittently driven, the amount of air blown to the indoor heat exchanger 6 is reduced as compared with the case where the indoor fan 7 is always driven. While the indoor fan 7 is decreasing, the temperature of the indoor heat exchanger 6 is decreased, the air around the indoor heat exchanger 6 is dehumidified, and the cooled air is not blown into the room, so the room temperature decreases. do not do. When the indoor fan 7 is driven, indoor air is sucked in, dehumidified when passing through the indoor heat exchanger 6, and dried air is blown out into the room. At this time, the room temperature is lowered, and the room temperature can be brought close to the set temperature.

In addition, this invention is not limited to the said embodiment, Of course, many corrections and changes can be added to the said embodiment within the scope of the present invention. In the air conditioner dedicated to the cooling operation or the integrated air conditioner, correction control of the dehumidifying operation may be performed.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Outdoor heat exchanger 4 Throttle device 5 Outdoor fan 6 Indoor heat exchanger 7 Indoor fan 10 Control apparatus 11 Outdoor temperature detector 12 Room temperature detector 13 Humidity detector 14 Indoor heat exchanger temperature detector

Claims

A compressor, outdoor heat exchanger, expansion device, and indoor heat exchanger form a refrigeration cycle, an indoor fan that sends indoor air to the indoor heat exchanger, and the compressor rotation speed is controlled according to the air conditioning operation. A control device that drives and controls the indoor fan according to the number of rotations of the machine, a temperature detector that detects the temperature of the indoor heat exchanger, and a humidity detector that detects the humidity in the room are provided. The air conditioning is characterized in that when performing the dehumidifying operation, correction control is performed to reduce the blowing capacity of the indoor fan so that the temperature of the indoor heat exchanger becomes a dew point temperature lower than the detected indoor humidity. Machine.
The indoor fan is driven at a reference rotational speed corresponding to the rotational speed of the compressor, and during the dehumidifying operation, the control device sets the rotational speed of the indoor fan to a rotational speed lower than the reference rotational speed and adjusts to the temperature of the indoor heat exchanger. The air conditioner according to claim 1, wherein the rotational speed of the indoor fan is changed accordingly.
When the control device changes the reference rotation speed in accordance with the change in the rotation speed of the compressor, the control apparatus changes the rotation speed of the indoor fan while maintaining the correction value of the rotation speed of the indoor fan before the change. The air conditioner according to claim 1 or 2.
A lower limit temperature lower than the dew point temperature is set, and the control device performs correction control when the temperature of the indoor heat exchanger is higher than the lower limit temperature, and performs correction control when the temperature of the indoor heat exchanger is equal to or lower than the lower limit temperature. The air conditioner according to any one of claims 1 to 3, wherein there is no air conditioner.
The louver for controlling the air blowing direction is provided, and when the air blowing capacity of the indoor fan is reduced, the control device operates the louver to change the air blowing direction. Air conditioner.