JP6906311B2 - Air conditioner - Google Patents

Description

The present invention relates to an air conditioner that controls ventilation in an indoor unit.

In the heating operation of the air conditioner, the temperature of the floor surface in the air-conditioned space tends to decrease because the warm air increases. Therefore, in the heating operation of the conventional air conditioner, the comfort is improved by transporting warm air to the feet by using a fan. Further, in order to improve the comfort during heating, for example, an air conditioner as described in Patent Document 1 has been proposed.

The air conditioner described in Patent Document 1 controls the blowing direction and the amount of air blown at that time according to the position of a person in the room and the intention of the user, and provides a more efficient and comfortable air-conditioned space. There is.

JP-A-2010-60250

By the way, recently, the airtightness and heat insulation of buildings have been improved, and the heating load tends to be reduced. When the heating load is small, the heating capacity of the air conditioner is also small and limited. Therefore, for example, in the air conditioner described in Patent Document 1, when the heating capacity of the indoor heat exchanger is small, if the air volume of the air blown out from the indoor unit is secured, the temperature of the blown air becomes low, so that the air conditioner is conveyed to the feet. The temperature of the air becomes low.

Further, when the air volume of the air blown out from the indoor unit is reduced, the temperature of the blown air rises. However, since the air volume of the blown air is small, the blown air having a lighter specific density than the cold air at the feet, that is, the warm air rises, and the warm air cannot be conveyed to the feet.

The present invention has been made in view of the above problems in the prior art, and an object of the present invention is to provide an air conditioner capable of supplying warm air to the feet of a user even when the heating load is small. And.

The air conditioner of the present invention is an air conditioner including a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger connected by a refrigerant pipe to circulate the refrigerant, and is in an air-conditioned space. An indoor blower that supplies indoor air, which is the air of the above, to the indoor heat exchanger, an indoor temperature sensor that measures the indoor temperature, which is the temperature of the air-conditioned space, and control modes such as a normal mode, a first mode, and a control mode. It has a second mode and includes a control device that controls the compressor and the indoor blower according to the control mode. In the first mode, the control device is a first compressor having a frequency lower than a set frequency. The compressor is operated at a frequency and the indoor blower is operated intermittently. In the second mode, the compressor is operated at a second compressor frequency lower than the first compressor frequency. In addition, the indoor blower is configured to intermittently operate at a rotation speed lower than the rotation speed in the first mode, and when the control mode is the normal mode, the compressor frequency of the compressor is said. When the frequency becomes equal to or lower than the set frequency, the control mode is changed from the normal mode to the first mode, and when the control mode is the first mode, the room temperature measured by the room temperature sensor becomes The control mode is changed from the first mode to the second mode when the frequency reduction start temperature set to a value higher than the set temperature and lower than the thermo OFF temperature at which the thermo is turned off is exceeded. be.

As described above, according to the air conditioner of the present invention, by intermittently operating the indoor blower, warm air can be supplied to the feet of the user even when the heating load is small.

It is the schematic which shows an example of the structure of the air conditioner which concerns on Embodiment 1. FIG. It is a block diagram which shows an example of the structure of the control device of FIG. It is the schematic for demonstrating the arrangement of the component | component of the indoor unit of FIG. It is the schematic for demonstrating the operation of each part in the air conditioner of FIG. It is a schematic diagram for demonstrating the relationship between the rotation speed of the indoor blower in the 1st FIO mode or the 2nd FIO mode, and a condensation temperature. It is a flowchart which shows an example of the flow of the process of FIO control in the air conditioner 1 which concerns on Embodiment 1. FIG. It is the schematic which shows an example of the structure of the air conditioner which concerns on Embodiment 2. FIG. It is the schematic for demonstrating the operation of each part in the air conditioner which concerns on Embodiment 2. FIG.

Embodiment 1.
Hereinafter, the air conditioner according to the first embodiment of the present invention will be described.

[Circuit configuration of air conditioner]
FIG. 1 is a schematic view showing an example of the configuration of the air conditioner 1 according to the first embodiment. As shown in FIG. 1, the air conditioner 1 is composed of an indoor unit 10, an outdoor unit 20, and a control device 30. The indoor unit 10 includes an indoor heat exchanger 11 and an indoor blower 12. The outdoor unit 20 includes a compressor 21, a refrigerant flow path switching device 22, an expansion valve 23, an outdoor heat exchanger 24, and an outdoor blower 25.

In the air conditioner 1, the compressor 21, the refrigerant flow path switching device 22, the indoor heat exchanger 11, the expansion valve 23, and the outdoor heat exchanger 24 are connected in an annular shape by the refrigerant pipe 2, so that the refrigerant circuit 3 is connected. It is configured. Then, the heat pump is formed by circulating the refrigerant in the refrigerant circuit 3 while repeating compression and expansion.

In this example, the outdoor unit 20 is provided with the expansion valve 23, but the present invention is not limited to this, and for example, the indoor unit 10 may be provided with the expansion valve 23. Further, the control device 30 may be provided in, for example, the indoor unit 10 or the outdoor unit 20, or may be provided in a place different from the indoor unit 10 and the outdoor unit 20.

(Indoor unit)
The indoor heat exchanger 11 exchanges heat between the air in the air-conditioned space (hereinafter, appropriately referred to as “indoor air”) supplied by the indoor blower 12 such as a fan and the refrigerant. As a result, heating air or cooling air, which is conditioned air supplied to the indoor space, is generated. The indoor heat exchanger 11 functions as an evaporator that evaporates the refrigerant during the cooling operation and cools the indoor air by the heat of vaporization at that time. Further, the indoor heat exchanger 11 functions as a condenser that dissipates the heat of the refrigerant to the indoor air and condenses the refrigerant during the heating operation.

The indoor blower 12 is a fan capable of varying the flow rate of air supplied to the indoor heat exchanger 11. As such a fan, for example, a centrifugal fan or a multi-blade fan driven by a motor such as a DC (Direct Current) fan motor can be used.

The pipe temperature sensor 13 is provided in the pipe on the outlet side during the heating operation of the indoor heat exchanger 11. The pipe temperature sensor 13 measures the temperature of the refrigerant flowing out of the indoor heat exchanger 11 during the heating operation, that is, the condensation temperature. The indoor temperature sensor 14 is provided in the vicinity of the indoor blower 12. The indoor temperature sensor 14 measures the temperature of the air taken in by the indoor blower 12, that is, the indoor temperature of the air-conditioned space.

(Outdoor unit)
The compressor 21 sucks in a low-temperature low-pressure refrigerant, compresses the refrigerant, puts it in a high-temperature and high-pressure state, and discharges the refrigerant. As the compressor 21, for example, an inverter compressor or the like that can control the capacity, which is the amount of refrigerant delivered per unit time, can be used by arbitrarily changing the drive frequency.

The refrigerant flow path switching device 22 is, for example, a four-way valve, and switches between cooling operation and heating operation by switching the flow direction of the refrigerant. The refrigerant flow path switching device 22 is not limited to the four-way valve described above, and may be used in combination with, for example, other valves.

The expansion valve 23 depressurizes the refrigerant and expands it. The expansion valve 23 is composed of a valve such as an electronic expansion valve whose opening degree can be controlled.

The outdoor heat exchanger 24 exchanges heat between the air supplied by the outdoor blower 25 such as a fan (hereinafter, appropriately referred to as “outdoor air”) and the refrigerant. Specifically, the outdoor heat exchanger 24 functions as a condenser during the cooling operation. Further, the outdoor heat exchanger 24 functions as an evaporator during the heating operation.

The outdoor blower 25 is a fan capable of varying the flow rate of air supplied to the outdoor heat exchanger 24. As such a fan, for example, a centrifugal fan or a multi-blade fan driven by a motor such as a DC (Direct Current) fan motor can be used.

(Control device)
The control device 30 is composed of, for example, a microcomputer, software executed on an arithmetic unit such as a CPU (Central Processing Unit), hardware such as a circuit device that realizes various functions, and the like.

The control device 30 includes, for example, the entire air conditioner 1 including the indoor unit and the outdoor unit 20 based on the setting by the user's operation for the remote controller (not shown) and various information received from each part of the indoor unit 10 and the outdoor unit 20. Control the operation. Specifically, the control device 30 controls, for example, the compressor frequency of the compressor 21, the rotation speeds of the indoor blower 12 and the outdoor blower 25, and the like, based on information from various sensors provided in the air conditioner 1. ..

FIG. 2 is a block diagram showing an example of the configuration of the control device 30 of FIG. As shown in FIG. 2, the control device 30 includes a frequency comparison unit 31, a temperature comparison unit 32, a frequency determination unit 33, a rotation speed determination unit 34, a wind direction plate operation determination unit 35, an operation control unit 36, and a storage unit 37. ing. Note that, in FIG. 2, only the portion related to the first embodiment is illustrated, and the illustration and description of the other portions are omitted.

The frequency comparison unit 31 compares the compressor frequency included in the frequency information supplied from the compressor 21 with the set frequency for the compressor frequency stored in the storage unit 37, which will be described later. The frequency comparison unit 31 supplies the comparison result to the frequency determination unit 33, the rotation speed determination unit 34, and the wind direction plate operation determination unit 35.

The temperature comparison unit 32 compares the room temperature included in the room temperature information supplied from the room temperature sensor 14 with various temperatures such as a set temperature with respect to the room temperature stored in the storage unit 37. The temperature comparison unit 32 supplies the comparison result to the frequency determination unit 33, the rotation speed determination unit 34, and the wind direction plate operation determination unit 35.

The frequency determination unit 33 determines the compressor frequency of the compressor 21 based on the comparison results supplied from each of the frequency comparison unit 31 and the temperature comparison unit 32. The frequency determination unit 33 supplies the operation control unit 36 with frequency information indicating the determined compressor frequency.

The rotation speed determination unit 34 of the indoor blower 12 is based on the comparison results supplied from each of the frequency comparison unit 31 and the temperature comparison unit 32 and the condensation temperature of the indoor heat exchanger 11 supplied from the pipe temperature sensor 13. Determine the number of revolutions. The rotation speed determination unit 34 supplies the rotation speed information indicating the determined rotation speed to the operation control unit 36.

The wind direction plate operation determination unit 35 determines the operation including the opening degree and the angle of the wind direction plate 16 based on the comparison results supplied from each of the frequency comparison unit 31 and the temperature comparison unit 32. The wind direction plate operation determining unit 35 supplies the wind direction plate information indicating the determined operation of the wind direction plate 16 to the operation control unit 36.

The operation control unit 36 generates control information for controlling the compressor frequency of the compressor 21 based on the frequency information supplied from the frequency determination unit 33, and supplies the control information to the compressor 21. Further, the operation control unit 36 generates control information for controlling the rotation speed of the indoor blower 12 based on the rotation speed information supplied from the rotation speed determination unit 34, and supplies the control information to the indoor blower 12. Further, the motion control unit 36 generates control information for controlling the operation of the wind direction plate 16 based on the wind direction plate information supplied from the wind direction plate operation determination unit 35, and supplies the control information to the wind direction plate 16.

The storage unit 37 stores information used in various processes described later, for example, various setting information regarding the compressor frequency, the room temperature, the condensation temperature, and the operation of the wind direction plate 16. The storage unit 37 reads out various setting information stored in response to requests from each of the frequency comparison unit 31, the temperature comparison unit 32, the frequency determination unit 33, the rotation speed determination unit 34, and the wind direction plate operation determination unit 35. , Supply to each.

[Structure of indoor unit]
Next, the arrangement of each component in the indoor unit 10 will be described. FIG. 3 is a schematic view for explaining the arrangement of the components of the indoor unit 10 of FIG. As shown in FIG. 3, the indoor unit 10 has an indoor heat exchanger 11, an indoor blower 12, a pipe temperature sensor 13, and an indoor temperature sensor 14 arranged inside the main body of the indoor unit 10. The indoor heat exchanger 11 is arranged on the downstream side of the air flow of the indoor blower 12.

Further, the indoor unit 10 is provided with a suction port (not shown) for sucking indoor air, which is an air-conditioning target space, and an air outlet 15 for sending harmonized air into the room, in a main body forming an outer shell. There is. The air outlet 15 forms a ventilation path on the downstream side of the indoor blower 12. The air outlet 15 is provided with a wind direction plate 16 such as a louver. The angle and open / closed state of the wind direction plate 16 can be changed based on the control of the control device 30. The direction of air blown from the air outlet 15 can be adjusted by changing the angle of the wind direction plate 16, and the opening area of the air outlet 15 can be adjusted by changing the open / closed state.

[Operation of air conditioner]
Next, the operation of the refrigerant in the air conditioner 1 having the above configuration will be described.
In the example shown in FIG. 1, the state shown by the solid line of the refrigerant flow path switching device 22 is the state of the heating operation mode. Here, only the operation of the refrigerant in the heating operation mode related to the present invention will be described, and the description of the cooling operation mode will be omitted.

(Heating operation mode)
In the heating operation mode, the refrigerant flow path switching device 22 is switched to the state shown by the solid line in FIG. Then, the low-temperature and low-pressure refrigerant is compressed by the compressor 21 and discharged as a high-temperature and high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 21 flows into the indoor heat exchanger 11 via the refrigerant flow path switching device 22.

The high-temperature and high-pressure gas refrigerant flowing into the indoor heat exchanger 11 exchanges heat with the indoor air taken in by the indoor blower 12 and condenses while radiating heat, becomes a high-pressure liquid refrigerant and flows out from the indoor heat exchanger 11. .. The high-pressure liquid refrigerant flowing out of the indoor heat exchanger 11 is depressurized by the expansion valve 23 to become a low-temperature low-pressure gas-liquid two-phase refrigerant, which flows into the outdoor heat exchanger 24.

The low-temperature, low-pressure gas-liquid two-phase refrigerant that has flowed into the outdoor heat exchanger 24 exchanges heat with the outdoor air to absorb and evaporate, and becomes a low-temperature, low-pressure gas refrigerant that flows out of the outdoor heat exchanger 24. The low-temperature low-pressure gas refrigerant flowing out of the outdoor heat exchanger 24 passes through the refrigerant flow path switching device 22 and is sucked into the compressor 21.

(FIO control)
Next, FIO (Fan Intermitent Operation) control by the air conditioner 1 according to the first embodiment will be described. In the first embodiment, FIO control is performed in order to improve the comfort of the feet when the heating load is small. The FIO control is a control in which the indoor blower 12 generates an air flow that delivers warm air to the feet even when the heating load is low.

FIG. 4 is a schematic view for explaining the operation of each part in the air conditioner 1 of FIG. In the first embodiment, the first FIO mode and the second FIO mode are used as the modes for performing FIO control. The first FIO mode is a mode applied when the FCO (Fan Communication Operation) mode, which is a control mode during normal operation, is first shifted to the FIO mode under a low heating load. In the first FIO mode, the indoor blower 12 is operated intermittently while the compressor 21 is continuously operated.

The second FIO mode is a mode applied when the heating load is lower than the heating load to which the first FIO mode is applied. In the second FIO mode, as in the first FIO mode, the indoor blower 12 is operated intermittently while the compressor 21 is continuously operated. At this time, in the second FIO mode, the compressor frequency of the compressor 21 is lowered as compared with that in the first FIO mode, and the rotation speed of the indoor blower 12 during operation is lowered as compared with that in the first FIO mode.

The "FCO mode" corresponds to the "normal mode" in the present invention. Further, the "first FIO mode" corresponds to the "first mode" in the present invention. Further, the "second FIO mode" corresponds to the "second mode" in the present invention.

As shown in FIG. 4, first, the heating load is reduced from the state in which the air conditioner 1 is operating in the FCO mode during normal operation, and the compressor frequency f _FCO of the compressor 21 is set to a preset frequency f _SET. When becomes (time t ₁ ), the control mode shifts to the first FIO mode. The compressor frequency f _{FCO at} this time is not a preset constant value, but a value that changes depending on the relationship between the set temperature and the room temperature.

When the control mode shifts to the first FIO mode, the compressor frequency is set to the preset constant frequency f _FIO while the operation of the compressor 21 is continued, and the rotation speed of the indoor blower 12 is increased. It is set to the preset rotation speed N _FIO . The compressor frequency f _{FIO at} this time is, for example, a value of about ½ _{from the lowest compressor frequency f MIN} to the set frequency f _SET. Further, it is assumed that the rotation speed N _FIO of the indoor blower 12 turns the indoor blower 12 ON or OFF, that is, intermittently operates at the same rotation speed as the rotation speed N _{FCO in the FCO mode.} The "compressor frequency f _FIO " corresponds to the "first compressor frequency" in the present invention.

Further, in the first FIO mode, the angle of the wind direction plate 16 provided at the air outlet 15 of the indoor unit 10 is changed, and the air blowing direction from the air outlet 15 is set to a preset direction, for example, downward. As a result, it is possible to prevent the warm air blown out from the air outlet 15 from rising up and allow the warm air to reach the floor surface.

When the horizontal direction with respect to the floor surface is 0 ° and the vertical direction is 90 °, the angle of the wind direction plate 16 at this time is preferably, for example, 45 ° or more, and more preferably 60 ° or more and 85 ° or less.

Next, when the indoor temperature Ta of the air-conditioned space becomes _{higher than the set temperature T SET} and equal to or higher than the preset temperature T _{FIO (time t 2} ), the control mode shifts to the second FIO mode. The temperature T _FIO is a temperature for shifting the control mode to the first FIO mode and lowering the compressor frequency of the compressor 21 as compared with the FCO mode. The temperature T _FIO is a temperature higher than the set temperature T _SET by a preset temperature ΔT ₁ , and “temperature T _FIO = set temperature T _SET + ΔT ₁ ”. Hereinafter, this temperature T _FIO will be appropriately referred to as “frequency reduction start-up temperature T _FIO ” and will be described.

When the control mode shifts to the second FIO mode, the compressor frequency is set to the preset constant frequency f _{FIO_L} while the operation of the compressor 21 is continued, and the rotation speed of the indoor blower 12 is increased. It is set to the preset rotation speed N _{FIO_L} . The compressor frequency f _{FIO_L at} this time is, for example, _{a value from the lowest compressor frequency f MIN} to about 1/2 of the compressor frequency f _FIO. Further, the rotation speed N _{FIO_L} of the indoor blower 12 shall be such that the indoor blower 12 is operated intermittently at a rotation speed of about 1/2 of the rotation speed N _FIO. The "compressor frequency f _{FIO_L} " corresponds to the "second compressor frequency" in the present invention.

Further, in the second FIO mode, the opening degree of the wind direction plate 16 is set to the half-open state, and the opening area of the air outlet 15 is about 1/2 of that in the FCO mode. At this time, the air volume is reduced by lowering the rotation speed of the indoor blower 12, but the wind speed of the air blown from the air outlet 15 can be maintained by setting the opening degree of the wind direction plate 16 to a half-open state. ..

Then, when the indoor temperature of the air-conditioned space becomes _{equal to or higher than the thermo-OFF temperature T-OFF,} which is the thermo-off for stopping the compressor 21, the operation of the indoor blower 12 is stopped. The thermo-OFF temperature T _OFF is a temperature higher than the set temperature T _SET by a preset temperature ΔT ₂ , and is “thermo OFF temperature T _OFF = T _SET + ΔT ₂ ”. The thermo-OFF temperature T _OFF is set to a value higher than the frequency reduction start temperature T _{FIO described above.} Further, when the surface temperature of the indoor heat exchanger 11 rises and the condensation temperature _{becomes High} or higher again while the operation of the indoor blower 12 is stopped, the indoor blower 12 restarts the operation.

Here, the ON or OFF timing of the indoor blower 12 is determined based on the condensation temperature. FIG. 5 is a schematic view for explaining the relationship between the rotation speed of the indoor blower 12 and the condensation temperature in the first FIO mode or the second FIO mode.

As shown in FIG. 5, in the first embodiment, two determination values of _{temperature T 1} and temperature T _{2 are preset for the condensation temperature CT of the indoor heat exchanger 11.} Then, the condensation temperature CT changes up and down between _{the temperature T 1} and the temperature T _2. At this time, the indoor blower 12 starts the operation _{when the condensation temperature CT exceeds the temperature T 1} , and stops the operation when the _{temperature falls below the temperature T 2.} That is, the indoor blower 12 is stopped at the rise time _{t r,} operated at fall time _{t f.}

More specifically with reference to FIG. 5, while the operation of the indoor blower 12 is stopped, the condensation temperature CT of the indoor heat exchanger 11 rises _{from the temperature T 2} to the temperature T _1. At time _{t 3,} the condensation temperature CT is reaches a temperature _{T 1,} the indoor blower 12 starts operating. During the operation of the indoor blower 12 from time t ₃ to time t ₄ , the indoor heat exchanger 11 is cooled by the blower, so that the condensation temperature CT drops from the temperature T _{1 to the temperature T 2.} Then, at time _{t 4,} the condensation temperature CT is drops to a temperature _{T 2,} the operation of the indoor blower 12 is stopped.

Thereafter, similarly, the operation of the indoor blower 12 at time t ₅ is started, the operation of the indoor blower 12 is stopped at time t _6. Further, operation of the indoor blower 12 at time t ₇ is started, operation of the indoor fan 12 is stopped at time t _8. The "temperature T ₁ " corresponds to the "first set temperature" in the present invention. Further, the "temperature T ₂ " corresponds to the "second set temperature" in the present invention.

FIG. 6 is a flowchart showing an example of the flow of FIO control processing in the air conditioner 1 according to the first embodiment. First, the air conditioner 1 is set to the FCO mode, which is a control mode during normal operation (step S1). At this time, the compressor frequency of the compressor 21 is set to the _{frequency f FCO.} Further, the rotation speed of the indoor blower 12 is set to the _{rotation speed NFCO.} Further, the wind direction plate 16 has an opening degree fully open and an arbitrary angle.

Next, the compressor 21 measures the current compressor frequency f and supplies it to the control device 30 (step S2). The frequency comparison unit 31 of the control device 30 compares the compressor frequency f measured in step S2 with the set frequency f _SET (step S3). In this process, it is determined whether or not to shift the control mode from the FCO mode to the FIO mode based on the relationship between the compressor frequency f and the set frequency f _SET.

As a result of comparison, when the compressor frequency f is _{equal to or less than the set frequency f SET} (step S3; YES), the control mode shifts from the FCO mode to the first FIO mode. Then, the operation control unit 36 of the control device 30 sets the compressor frequency to the frequency f _FIO and sets the rotation speed of the indoor blower 12 to the rotation speed N _FIO . Further, the operation control unit 36 is set so that the opening degree of the wind direction plate 16 is fully open and the angle is downward (step S4). On the other hand, when the compressor frequency f is _{larger than the set frequency f SET} (step S3; NO), the process returns to step S1 and the FCO mode is maintained.

Next, the indoor temperature sensor 14 measures the indoor temperature Ta and supplies the measurement result to the control device 30 (step S5). The temperature comparison unit 32 of the control device 30 compares the room temperature Ta measured in step S5 with the frequency reduction start-up temperature _TFIO (step S6). In this process, it is determined whether or not the control mode is set to the second FIO mode based on the relationship between the room temperature Ta and the frequency reduction start temperature T _FIO.

As a result of comparison, when the room temperature Ta is _{larger than the frequency reduction start temperature T FIO} (step S6; YES), the control mode shifts to the second FIO mode. Then, the operation control unit 36 sets the compressor frequency from f _FIO to f _{FIO_L,} and sets the rotation speed of the indoor blower 12 from N _{FIO to N FIO_L} . Further, the operation control unit 36 is set so that the opening degree of the wind direction plate 16 is in the half-open state and the angle is downward (step S7). On the other hand, when the room temperature Ta is _{equal to or lower than the frequency reduction start temperature T FIO} (step S6; NO), the process returns to step S5.

Next, the indoor temperature sensor 14 measures the indoor temperature Ta and supplies the measurement result to the control device 30 (step S8). The temperature comparison unit 32 compares the indoor temperature Ta measured in step S8 with the thermo-OFF temperature T _OFF that stops the blowing of the indoor blower 12 (step S9). In this process, it is determined whether or not to stop the operation of the indoor blower 12 based on the relationship between the indoor temperature Ta and the thermo-OFF temperature T _OFF.

As a result of comparison, when the room temperature Ta is _{larger than the thermo-OFF temperature T-OFF} (step S9; YES), the operation control unit 36 stops the operation of the compressor 21 to turn off the thermo (step S10). Then, the process returns to step S8, and the processes of steps S8 to S10 are repeated until the room temperature Ta becomes equal to or lower than the _{thermo-OFF temperature T OFF.}

On the other hand, when the indoor temperature Ta is _{equal to or lower than the thermo-OFF temperature T OFF} (step S9; NO), the indoor temperature sensor 14 measures the indoor temperature Ta (step S11). The temperature comparison unit 32 compares the room temperature Ta measured in step S11 with the set temperature T _SET (step S12). In this process, it is determined whether or not the control mode is set to the normal operation mode (FCO mode) based on the relationship between the room temperature Ta and the set temperature T _SET.

As a result of comparison, when the room temperature Ta is _{larger than the set temperature T SET} (step S12; YES), the process returns to step S2, and the control mode is set to the first FIO mode. On the other hand, when the room temperature Ta is _{equal to or lower than the set temperature T SET} (step S12; NO), the process returns to step S1 and the control mode is set to the FCO mode.

As described above, the air conditioner 1 according to the first embodiment is a refrigerant that circulates the refrigerant by connecting the compressor 21, the indoor heat exchanger 11, the expansion valve 23, and the outdoor heat exchanger 24 with the refrigerant pipe 2. A circuit 3 is provided, an indoor blower 12 for supplying indoor air to the indoor heat exchanger 11, an indoor temperature sensor 14 for measuring the indoor temperature, and FCO mode, the first FIO mode, and the first FIO mode as control modes. It has a 2FIO mode and includes a control device 30 that controls the compressor 21 and the indoor blower 12 according to the control mode. The control device 30 is configured to operate the compressor 21 at a compressor frequency f _{FIO lower than the set frequency f SET} in the first FIO mode and intermittently operate the indoor blower 12. In the second FIO mode, the controller 30 is configured to operate the compressor intermittently. _{The compressor 21 is operated at a compressor frequency f FIO_L} lower than the frequency f _FIO , and the indoor blower 12 is intermittently operated at a rotation speed lower than the rotation speed in the first FCO mode. The control device 30 changes the control mode from the FCO mode to the first FIO mode when the control mode is the FCO mode and the compressor frequency of the compressor 21 _{becomes equal to or lower than the set frequency f SET, and the control mode is changed.} In the first FIO mode, the room temperature measured by the room temperature sensor 14 exceeds the frequency reduction start temperature T _{FIO set to a value higher than the set temperature T SET and} lower than the thermo OFF temperature T _OFF. Occasionally, the control mode is changed from the first FIO mode to the second FIO mode.

In this way, when the compressor frequency of the compressor 21 is _{equal to or lower than the set frequency f SET} , the temperature of the air blown out from the outlet 15 of the indoor unit 10 is lowered by intermittently operating the indoor blower 12 when the heating load is low. Can be suppressed and warm air can reach the floor surface.

Further, when the room temperature exceeds the frequency reduction start temperature T _{FIO in the first FIO} mode, the rise in the room temperature can be suppressed by changing the control mode to the second FIO mode. Then, since the rise in the indoor temperature can be suppressed, the indoor temperature is suppressed from reaching the thermo-OFF temperature, so that the operation of the compressor can be continued and the start and stop of the compressor can be suppressed. Further, energy saving can be improved by suppressing the start and stop of the compressor.

Embodiment 2.
Next, the air conditioner according to the second embodiment will be described. The air conditioner according to the second embodiment is different from the first embodiment described above in that a plurality of indoor units are provided in the air-conditioned space. In the following description, the same reference numerals are given to the parts common to the above-described first embodiment, and detailed description thereof will be omitted.

[Configuration of air conditioner]
FIG. 7 is a schematic view showing an example of the configuration of the air conditioner 100 according to the second embodiment. As shown in FIG. 7, the air conditioner 100 includes a centralized control device 130, a plurality of indoor units 10A to 10C, and a plurality of communication devices 50A to 50C. Each of the indoor units 10A to 10C is connected to the centralized control device 130 via the communication devices 50A to 50C, and each is connected in parallel. The connection between the indoor units 10A to 10C and the communication devices 50A to 50C, and the connection between the communication devices 50A to 50C and the centralized control device 130 can be wired as long as various information such as control commands and device information can be exchanged. It may be wireless.

The plurality of indoor units 10A to 10C have the same functions as the indoor units 10 in the first embodiment. The centralized control device 130 replaces the control device 30 in the first embodiment described above, and controls the operation of the indoor units 10A to 10C via the communication devices 50A to 50C respectively. In this example, it has been described that three indoor units 10A to 10C are provided, but the present invention is not limited to this, and for example, two units may be used, or four or more units may be provided.

[FIO control of air conditioner]
Next, the FIO control in the air conditioner 100 according to the second embodiment will be described. In the second embodiment, the indoor units 10A to 10C perform FIO control in the same manner as in the first embodiment. At this time, the centralized traffic control device 130 controls the indoor units 10A to 10C so that the timing of transition from the FCO mode to the first FIO mode and from the first FIO mode to the second FIO mode is different.

FIG. 8 is a schematic view for explaining the operation of each part in the air conditioner 100 according to the present embodiment. As shown in FIG. 8, for example, the indoor unit 10B delays the timing of shifting from the FCO mode to the first FIO mode with respect to the indoor unit 10A by a time ΔT corresponding to the operation period of the indoor blower 12 of the indoor unit 10A. .. Similarly, regarding the timing of shifting to the second FIO mode, the indoor unit 10B delays the operation period of the indoor blower 12 of the indoor unit 10A.

Regarding the indoor unit 10C, the control mode may be switched at the same timing as either of the indoor unit 10A or 10B. As a result, in the air-conditioned space, harmonious air is always blown out from any one of the plurality of indoor units 10A to 10C.

As described above, in the air conditioner 100 according to the second embodiment, a plurality of indoor units 10A to 10C each having an indoor heat exchanger 11 and an indoor blower 12 are connected in parallel, and a plurality of centralized control devices 130 are used. Each indoor blower 12 in the indoor units 10A to 10C is controlled, and in the first FIO mode and the second FIO mode, the operation period in the intermittent operation of at least one of the plurality of indoor blowers 12 is set as the remaining operation period. The plurality of indoor blowers 12 are controlled so as to be different from the operation period in the intermittent operation of the indoor blowers 12. As a result, warm air can always be blown from any of the plurality of indoor units 10A to 10C, so that warm air can always be supplied to the floor surface.

Although the first and second embodiments of the present invention have been described above, the present invention is not limited to the above-described first and second embodiments of the present invention, and varies within the range not deviating from the gist of the present invention. Can be transformed and applied. For example, in the second embodiment, it has been described that the operation cycles of the indoor blowers 12 in the plurality of indoor units 10A to 10C are delayed by half a cycle from each other, but this is not limited to this example. For example, if the number of indoor units 10 is taken into consideration and the conditioned air is always blown out from one of the plurality of indoor units 10A to 10C, the conditioned air can be arbitrarily set. ..

1 Air conditioner, 2 Refrigerant piping, 3 Refrigerant circuit, 10, 10A, 10B, 10C Indoor unit, 11 Indoor heat exchanger, 12 Indoor blower, 13 Pipe temperature sensor, 14 Indoor temperature sensor, 15 Air outlet, 16 Wind direction plate , 20 outdoor unit, 21 compressor, 22 refrigerant flow path switching device, 23 expansion valve, 24 outdoor heat exchanger, 25 outdoor blower, 30 controller, 31 frequency comparison unit, 32 temperature comparison unit, 33 frequency determination unit, 34 Rotation speed determination unit, 35 wind direction plate operation determination unit, 36 operation control unit, 37 storage unit, 50A, 50B, 50C communication device, 100 air conditioner, 130 centralized control device.

Claims (8)

An air conditioner equipped with a refrigerant circuit that circulates refrigerant by connecting a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger with a refrigerant pipe.
An indoor blower that supplies indoor air, which is the air in the air-conditioned space, to the indoor heat exchanger.
An indoor temperature sensor that measures the indoor temperature, which is the temperature of the air-conditioned space,
The control mode has a normal mode, a first mode, and a second mode, and includes a control device that controls the compressor and the indoor blower according to the control mode.
The control device is
In the first mode, the compressor is operated at a first compressor frequency lower than the set frequency, and the indoor blower is operated intermittently.
In the second mode, the compressor is operated at a second compressor frequency lower than the first compressor frequency, and the indoor blower is interrupted at a rotation speed lower than the rotation speed in the first mode. Configured to drive
When the control mode is the normal mode and the compressor frequency of the compressor becomes equal to or lower than the set frequency, the control mode is changed from the normal mode to the first mode.
When the control mode is the first mode, the frequency reduction start-up in which the room temperature measured by the room temperature sensor is set to a value higher than the set temperature and lower than the thermo-OFF temperature at which the thermo is turned off. An air conditioner comprising changing the control mode from the first mode to the second mode when the temperature is exceeded. It is provided at the air outlet of the main body and is further equipped with a wind direction plate that adjusts the angle and opening.
The control device is
The air conditioner according to claim 1, wherein when the control mode is the first mode, the angle of the wind direction plate is controlled so that the air blowing direction of the air outlet becomes the set direction. The control device is
The air conditioner according to claim 2, wherein the angle of the wind direction plate is 45 ° or more when the horizontal angle with respect to the floor surface is 0 ° and the vertical angle is 90 °. The control device is
The air conditioning according to claim 2 or 3, wherein the opening degree of the wind direction plate is controlled so that the opening area of the air outlet becomes the set area when the control mode is the second mode. Device. Further equipped with a pipe temperature sensor for measuring the condensation temperature of the indoor heat exchanger,
The control device is
The invention according to any one of claims 1 to 4, wherein when the control mode is the first mode or the second mode, the timing of the intermittent operation of the indoor blower is determined based on the condensation temperature. The described air conditioner. The control device is
When the condensation temperature becomes higher than the first set temperature, the indoor blower is operated.
The air conditioner according to claim 5, wherein the indoor blower is stopped when the condensation temperature becomes lower than the second set temperature, which is lower than the first set temperature. The control device is
When the control mode is the second mode,
When the room temperature is higher than the set temperature, the control mode is shifted from the second mode to the first mode.
The air conditioner according to any one of claims 1 to 6, wherein when the room temperature becomes equal to or lower than the set temperature, the control mode is shifted from the second mode to the normal mode. .. A plurality of indoor units having the indoor heat exchanger and the indoor blower are connected in parallel.
The control device is
Control each of the indoor blowers in the plurality of indoor units,
In the first mode and the second mode, the operation period in the intermittent operation of at least one of the plurality of indoor blowers is different from the operation period in the intermittent operation of the remaining indoor blowers. The air conditioner according to any one of claims 1 to 7, wherein the plurality of indoor blowers are controlled.

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