JP2002106925A - Air conditioner - Google Patents

Abstract

(57) [Problem] To provide an air conditioner capable of always ensuring stable and appropriate dehumidifying ability during dry operation and achieving comfortable air conditioning and energy saving effect. SOLUTION: During a dry operation, the number of revolutions N of an outdoor fan 8 is controlled in accordance with the temperature detected by an indoor temperature sensor 22, and a cool dry, an isothermal dry, and a warm dry with different dry air temperatures are selectively executed. I do. During cold dry and isothermal dry, the opening of the PMV 6 is controlled so that the degree of superheat of the refrigerant in the indoor heat exchanger 7 functioning as an evaporator becomes a constant value, and during warm dry, the PMV 6 is kept at a constant opening. maintain.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner having a dry operation function.

[0002]

2. Description of the Related Art In an air conditioner, two indoor heat exchangers are connected via an expansion valve with a variable throttle amount, and the expansion valves are fully opened so that both indoor heat exchangers function as an evaporator. In some cases, the cooling operation is executed by the air conditioner and the dry operation is executed by restricting the expansion valve so that one of the indoor heat exchangers functions as an evaporator and the other functions as a reheater (condenser). That is, in the dry operation, the air cooled and dehumidified by the evaporator is reheated by the reheater, reaches the normal temperature, and is blown into the room.

[0003]

Although the humidity in a room is removed by the dry operation, it is important to sufficiently consider the temperature fluctuation in the room when dehumidifying the room.

[0004] In dry operation, it is desirable to always ensure stable and appropriate dehumidifying ability.

[0005] The present invention has been made in view of the above circumstances,
It is an object of the air conditioner of the first aspect to make it possible to moderate the fluctuation of the room temperature during the dry operation and to improve the comfort.

The air conditioner according to claims 2 to 5 is
It is an object of the present invention to always secure stable and appropriate dehumidifying ability during dry operation to obtain comfortable air conditioning and energy saving effects.

[0007]

According to the first aspect of the present invention, an air conditioner includes a compressor, an outdoor heat exchanger, an expansion mechanism, a first indoor heat exchanger, an expansion mechanism with a variable throttle amount, and a second indoor heat exchanger. A connected refrigeration cycle, an outdoor fan that circulates outdoor air to the outdoor heat exchanger, and an outdoor heat exchanger, an expansion mechanism, a first indoor heat exchanger, and a variable expansion amount of refrigerant discharged from the compressor. A means for flowing through the second indoor heat exchanger and squeezing the expansion mechanism to fully open an expansion mechanism with a variable throttle amount to execute a cooling operation; and an outdoor heat exchanger for discharging refrigerant discharged from the compressor. Means for flowing through a mechanism, a first indoor heat exchanger, a variable expansion amount expansion mechanism, and a second indoor heat exchanger and fully opening the expansion mechanism to restrict the variable expansion amount expansion mechanism to perform a dry operation; An indoor temperature sensor for detecting temperature;
Means for controlling the number of rotations of the outdoor fan according to the detected temperature and the detected humidity of the indoor temperature sensor during the dry operation, and selectively performing a cool dry, an isothermal dry, and a warm dry with different dry air temperatures. And

According to a second aspect of the present invention, there is provided an air conditioner comprising a refrigeration cycle including a compressor, an outdoor heat exchanger, a first electronic expansion valve, a first indoor heat exchanger, a second electronic expansion valve, and a second indoor heat exchanger. When,
An outdoor fan that circulates outdoor air through the outdoor heat exchanger; and an outdoor heat exchanger, a first electronic expansion valve, a first indoor heat exchanger, a second electronic expansion valve, and a second refrigerant that discharge refrigerant discharged from the compressor. Means for flowing through the indoor heat exchanger and squeezing the first electronic expansion valve to fully open the second electronic expansion valve to execute a cooling operation;
The refrigerant discharged from the compressor flows through an outdoor heat exchanger, a first electronic expansion valve, a first indoor heat exchanger, a second electronic expansion valve, a second indoor heat exchanger, and the first electronic expansion valve Means for fully opening the second electronic expansion valve to perform a dry operation, a room temperature sensor for detecting a room temperature, and a rotation of the outdoor fan according to a detected temperature and a detected humidity of the room temperature sensor during the dry operation. A means for controlling the number and selectively performing cold dry, isothermal dry, warm dry with different dry air temperatures, and cold dry and isothermal dry,
Means for controlling the degree of opening of the second electronic expansion valve so that the degree of superheat of the refrigerant in the second indoor heat exchanger is constant, and maintaining the degree of opening of the second electronic expansion valve at a constant degree during warm, dry operation Means to perform.

According to a third aspect of the present invention, in the air conditioner, the degree of opening of the second electronic expansion valve is controlled so that the temperature of the first indoor heat exchanger or the second indoor heat exchanger becomes a constant value when the apparatus is warm and dry. The air conditioner according to the second aspect differs from the air conditioner of the second aspect only in the function at the time of warm drying.

According to a fourth aspect of the present invention, the air conditioner includes means for maintaining the second electronic expansion valve at a constant opening in accordance with the capacity of the compressor when the apparatus is warm and dry. It is different from the air conditioner of claim 2.

According to a fifth aspect of the present invention, in the air conditioner, the second electronic expansion is performed such that the temperature of the first indoor heat exchanger or the second indoor heat exchanger becomes a constant value corresponding to the capacity of the compressor at the time of warm drying. The air conditioner is provided with a means for controlling the opening degree of the valve.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a discharge port of the compressor 1
The outdoor heat exchanger 3 is connected via the four-way valve 2. The outdoor heat exchanger 3 is connected to a first indoor heat exchanger 5 via an expansion mechanism such as a first electronic expansion valve 4. The first indoor heat exchanger 5 is connected to a second indoor heat exchanger 7 via a variable expansion mechanism, for example, a second electronic expansion valve 6, and the second indoor heat exchanger 7 is provided via the four-way valve 2. Connected to the suction port of compressor 1.

The electronic expansion valves 4 and 6 are pulse motor valves whose opening continuously changes in accordance with the number of input drive pulses. Hereinafter, this pulse motor valve is referred to as P
Abbreviated as MV.

The compressor 1 is a variable capacity compressor, and a drive motor is connected to an inverter circuit 11. The inverter circuit 11 rectifies the voltage of the commercial AC power supply 10, converts the rectified voltage into AC having a frequency corresponding to a command from the control unit 20, and outputs the AC. This output is the driving power of the compressor motor.

An outdoor fan 8 is provided near the outdoor heat exchanger 3. The outdoor fan 8 circulates outside air to the outdoor heat exchanger 3, and a motor 8M is connected to the phase control circuit 12. This phase control circuit 12 is connected to the commercial AC power supply 10.
The phase of the power supply to the motor 8M is controlled in accordance with a command from the control unit 20. By this phase control, the rotation speed of the outdoor fan 8 can be changed.

An indoor fan 9 is provided near the indoor heat exchangers 5 and 7.
Is provided. The indoor fan 9 is connected to the indoor heat exchangers 5 and 7.
The motor 9 </ b> M is connected to the commercial AC power supply 10 via the tap switching circuit 13. The tap switching circuit 13 includes a speed switching tap H (high speed), M
It has (medium speed), L (low speed), L- (very low speed), and UL (ultra low speed), and performs tap switching according to a command from the control unit 20.

A temperature sensor 14 is attached to a connecting pipe between the second electronic expansion valve 6 and the second indoor heat exchanger 7. A temperature sensor 15 is attached to a connection pipe between the second indoor heat exchanger 7 and the four-way valve 2 at a position close to the second indoor heat exchanger 7.
Further, a temperature sensor 16 is attached at a position near the first indoor heat exchanger 5 in a connection pipe between the PMV 4 and the first indoor heat exchanger 5.

The control section 20 is composed of a microcomputer and its peripheral circuits, and controls the entire air conditioner. The control unit 20 includes a remote control type operation device (hereinafter, abbreviated as a remote controller) 21, an indoor temperature sensor 22, an indoor humidity sensor 23, and an outdoor temperature sensor 2.
4, four-way valve 2, PMV4, PMV6, inverter circuit 1
1, a phase control circuit 12, a tap switching circuit 13, and temperature sensors 14, 15, 16 are connected.

The control section 20 has the following functional means.

[1] The compressor 1 is operated, and the refrigerant discharged from the compressor 1 is supplied to the four-way valve 2, the outdoor heat exchanger 3, the PMV 4,
First indoor heat exchanger 5, PMV6, second indoor heat exchanger 7,
Means for flowing through the four-way valve 2, controlling the throttle of the PMV 4 and fully opening the PMV 6 to execute a cooling operation.

[2] Degree of superheating of the refrigerant in the indoor heat exchangers 5 and 7 functioning as evaporators during the cooling operation (= temperature sensor 15)
Means for controlling the opening degree (aperture amount) of the PMV 4 so that the detected temperature (the detected temperature of the temperature sensor 16) becomes a constant value.

[3] At the time of cooling operation, the condition for allocating the frequency and the number of revolutions predetermined for the cooling in the internal memory, the room temperature Ta detected by the room temperature sensor 22 and the room humidity detected by the room humidity sensor 23 From Ha, the operating frequency of compressor 1 (output frequency of inverter circuit 11) F
And means for setting the number of revolutions of the indoor fan 9 (based on switching of the tap switching circuit 13).

[4] The compressor 1 is operated, and the refrigerant discharged from the compressor 1 is supplied to the four-way valve 2, the outdoor heat exchanger 3, the PMV 4,
First indoor heat exchanger 5, PMV6, second indoor heat exchanger 7,
Flow through the four-way valve 2 and fully open PMV4
6. A means for controlling the aperture of 6 and performing a dry operation.

[5] At the time of the dry operation, the frequency and rotation number allocation conditions for the dry determined in advance in the internal memory;
Means for setting the operating frequency F of the compressor 1 and the number of revolutions of the indoor fan 9 from the indoor temperature Ta and the indoor humidity Ha.

[6] During the dry operation, the number of rotations of the outdoor fan 8 (the phase control circuit 12) depends on the detected indoor temperature Ta.
Means for controlling N, thereby adjusting the amount of sensible heat, and selectively performing cool dry, isothermal dry, and warm dry with different dry air temperatures.

[7] Cold dry and isothermal dry
Means for controlling the opening degree (throttle amount) of the PMV 6 such that the degree of superheat of the refrigerant in the indoor heat exchanger 7 functioning as an evaporator (= detected temperature of the temperature sensor 15−detected temperature of the temperature sensor 14) becomes a constant value.

[8] Means for maintaining the PMV 6 at a constant opening during warm and dry.

[9] The compressor 1 is operated, and the refrigerant discharged from the compressor 1 is supplied to the four-way valve 2, the second indoor heat exchanger 7, and the PMV.
6, first indoor heat exchanger 5, PMV4, outdoor heat exchanger 3,
Flow through the four-way valve 2 and fully open PMV6 for PMV
Means for controlling the throttle of 4 and performing a heating operation.

[10] During the heating operation, PM is set so that the degree of superheat of the refrigerant in the outdoor heat exchanger 3 functioning as an evaporator becomes a constant value.
Means for controlling the opening of V4. A temperature sensor for detecting the degree of superheat of the refrigerant in the outdoor heat exchanger 3 is provided at an intermediate position of the outdoor heat exchanger 3 and between the outdoor heat exchanger 3 and the four-way valve 2 (not shown).

[11] Means for controlling the operating frequency F of the compressor 1 according to the room temperature Ta during the heating operation.

[12] Means for selecting one of the cooling operation, the dry operation, and the heating operation in accordance with the setting mode of the remote controller 21.

[13] Means for selecting the setting of the cooling / dry mode or the execution of the heating operation according to the area of the room temperature Ta when the automatic mode is set by the remote controller 21.

[14] When the cooling / dry mode is set, means for selecting the execution of the cooling operation or the execution of the dry operation from the room temperature Ta and the room humidity Ha and the operation mode selection conditions predetermined in the internal memory in advance. .

Next, FIG. 2 shows the internal structure of the indoor unit in which the indoor heat exchangers 5 and 7 are mounted.

An indoor unit 30 has an air inlet 31 at the front and an air outlet 32 at the lower part. Inside, a heat insulating material 33 is provided on the back side, between the heat insulating material 33 and the front surface, and from the air inlet 31 to the air outlet 32,
The ventilation path 34 is formed. PMV
6, indoor heat exchanger 7, indoor heat exchanger 5, indoor fan 9,
A louver 35 is provided.

The indoor heat exchanger 7 and the indoor heat exchanger 5 are arranged by arranging two heat exchangers located on the leeward and leeward sides on a common fin made of aluminum. The leeward side is an indoor heat exchanger 5. The central portions of the indoor heat exchangers 7 and 5 are bent in the shape of a "<" to reduce the size of the unit housing.

It should be noted that the indoor heat exchangers 7 and 5 having such an integral structure can be used during the dry operation to be described later.
The drain generated in the (evaporator) flows into the indoor heat exchanger 5 (= reheater), which evaporates in the indoor heat exchanger 5 and is blown out into the room, which may cause a decrease in dehumidifying performance.

Therefore, slots 40 are formed at intermediate positions in the fins of both heat exchangers. That is, the drain generated in the indoor heat exchanger 7 (= evaporator) is guided downward by the slot 40.

However, in the indoor heat exchangers 7 and 5 having the shape of a “<”, as shown in FIG. 3, the drain generated at the upper part of the indoor heat exchanger 7 and once flowing into the slot 40 is the indoor heat exchanger. It may drop toward the lower part of the exchanger 5.

In order to solve this problem, as shown in FIG. 4, the upper edge of the plate-shaped drain guide 41 is inserted into the slot 40 on the upper side of the indoor heat exchangers 7, 5, and The lower edge is inserted into the slot 40 on the lower side of the indoor heat exchangers 7,5. The drain guide 41 has a “<” shape corresponding to the bending of the indoor heat exchangers 7 and 5.

That is, the drain generated on the upper side of the indoor heat exchanger 7 flows along the plate surface of the slot 40 and the drain guide 41 and is guided downward without dripping to the lower side of the indoor heat exchanger 5. Therefore, a decrease in dehumidifying performance is prevented. Moreover, due to the presence of the drain guide 41,
Useless ventilation at the bent portion is eliminated, and heat exchange efficiency can be improved.

FIG. 5 shows another structure for preventing the deterioration of the dehumidifying performance. This is because the connecting piece 42 which is a component of the fin is provided at the bent portion between the upper part and the lower part of the indoor heat exchanger 7.
It is a configuration to leave.

As shown in FIG. 6, the connection piece 42 is formed in advance by making a cut in a fin at a position where the indoor heat exchangers 7 and 5 are to be bent before the indoor heat exchangers 7 and 5 are bent. By being bent, it is formed in a plate-like shape and in the shape of a "ku".

That is, the drain generated on the upper side of the indoor heat exchanger 7 flows along the slot 40 and the connecting piece 42 and is guided downward without dripping on the lower side of the indoor heat exchanger 5. Therefore, a decrease in dehumidifying performance is prevented.
Moreover, the presence of the connecting piece 42 eliminates useless ventilation at the bent portion, and improves the heat exchange efficiency.

Next, the overall operation will be described.

It is assumed that the remote controller 31 has set the automatic mode. In this case, if the room temperature Ta detected by the room temperature sensor 22 is in the higher cooling / drying area, the cooling / dry mode is set.

When the cooling / dry mode is set, the cooling operation is performed based on the room temperature Ta, the room humidity Ha detected by the room humidity sensor 23, and the operation mode selection condition previously set in the internal memory of the control unit 20. Execution, execution of a dry operation, or execution of a ventilation operation is selected.

That is, if the room temperature Ta is sufficiently higher than the set temperature Ts on the remote controller 21, the cooling operation is executed, and if the room temperature Ta is within a predetermined range centered on the set temperature Ts, the dry operation is performed. Is executed and the room temperature T
When a falls below the set temperature Ts and deviates from the predetermined range, the air blowing operation is executed.

In the cooling operation, the operation of the compressor 1 and the four-way valve 2
Inactive (neutral state), throttle of PMV4, PM
Full opening of V6, operation of the outdoor fan 8, and operation of the indoor fan 9 are set.

In this case, the refrigerant is discharged from the compressor 1,
It enters the outdoor heat exchanger 3 through the four-way valve 2. In the outdoor heat exchanger 3, the refrigerant releases heat to the outside air and liquefies. The refrigerant that has passed through the outdoor heat exchanger 3 is decompressed by the PMV 4 so as to be easily vaporized, and enters the indoor heat exchanger 5. The refrigerant that has entered the indoor heat exchanger 5 also flows into the indoor heat exchanger 7 through the PMV 6 that is fully open. In the indoor heat exchangers 5, 7, the refrigerant takes heat from the indoor air and evaporates. The refrigerant having passed through the indoor heat exchangers 5 and 7 returns to the compressor 1 through the four-way valve 2.

In this way, the refrigerant flows in the direction indicated by the solid arrows in FIG. 1 to form a cooling cycle, and the outdoor heat exchanger 3 functions as a condenser and the indoor heat exchangers 5 and 7 both function as evaporators. Is cooled.

During the cooling operation, the PMV 4 is controlled so that the degree of superheat of the refrigerant in the indoor heat exchangers 5 and 7 functioning as evaporators (= detected temperature of the temperature sensor 15−detected temperature of the temperature sensor 16) becomes constant. The opening is controlled. Thereby, stable and appropriate cooling capacity is secured.

In the dry operation, the operation of the compressor 1, the non-operation of the four-way valve 2, the full opening of the PMV 4, the throttle of the PMV 6, the operation of the outdoor fan 8, and the operation of the indoor fan 9 are set.

In this case, the refrigerant is discharged from the compressor 1,
It passes through the four-way valve 2 and the outdoor heat exchanger 3 and from there through the PMV 4 into the indoor heat exchanger 5. In the indoor heat exchanger 5, the refrigerant emits heat to indoor air and liquefies. The refrigerant that has passed through the indoor heat exchanger 5 is decompressed by the PMV 6 so as to be easily vaporized, and enters the indoor heat exchanger 7. In the indoor heat exchanger 7, the refrigerant takes heat from indoor air and evaporates. The refrigerant that has passed through the indoor heat exchanger 7 returns to the compressor 1 through the four-way valve 2.

Thus, the refrigerant flows in the direction indicated by the solid arrow in FIG. 1 to form a dry cycle, and the outdoor heat exchanger 3
, The indoor heat exchanger 5 also works as a condenser (reheater), and the indoor heat exchanger 7 works as an evaporator.

Accordingly, the indoor air is cooled by the indoor heat exchanger 7, and the moisture contained in the indoor air becomes a drain and adheres to the indoor heat exchanger 7. The dry air cooled and dehumidified by the indoor heat exchanger 7 is warmed by the indoor heat exchanger 5, which is a reheater, and is blown into the room.

At the time of this dry operation, the compressor 1 is determined on the basis of the predetermined frequency and rotation number allocation conditions for drying shown in FIG. 7 and the detected room temperature Ta and room humidity Ha.
Is set, and the operating frequency F of the indoor fan 9 is set.

Under the frequency / rotation speed allocation condition shown in FIG.
The numerical value in the upper part is the operating frequency F, the alphabet of interruption is the number of revolutions, and the operating frequency F is assigned over a wide range around the set temperature Ts and the set humidity Hs. The lower numerical value is the rotation speed N of the outdoor fan 8 (based on the output of the phase control circuit 12).

For example, the difference (Ta-Ts) between the room temperature Ta and the set temperature Ts is 0 deg to 0.5 deg, and the difference (Ha-Hs) between the room humidity Ha and the set humidity Hs is + 5% to + 10%. If it is in the zone (the shaded zone in the figure), the operating frequency F = 28H
z, the ultra-low speed UL of the indoor fan 9 and the speed N = 200 rpm of the outdoor fan 8 are set.

As described above, the dry-only allocation condition is prepared, and the operating frequency F is allocated over a wide range centered on the set temperature Ts and the set humidity Hs, thereby lowering the cooling capacity based on the room temperature Ta. Regardless, the necessary and sufficient dehumidifying capacity (latent heat) can be secured. Therefore, the room humidity Ha can be reliably and quickly reached to the set humidity Hs, and the comfort can be improved.

In this case, the rotational speed N of the outdoor fan 8 is set by the lower numerical value in the allocation condition, which is selected from the cool dry operation, the isothermal dry operation, and the warm dry operation according to the indoor temperature Ta. It is for.

When the room temperature Ta is low, the warm dry operation is selected. In this warm dry operation, the outdoor fan 8 is operated at the rotation speed N = 0 rpm or the rotation speed N = 100 rpm. In this case, since the heat radiation of the refrigerant in the outdoor heat exchanger 3 is small (the amount of sensible heat is small), the amount of heat applied to the reheater (the indoor heat exchanger 5) is increased, and the dry air is sufficiently warmed to be indoors. It is blown out.

If the room temperature Ta is close to the set temperature Ts,
Isothermal dry operation is selected. In this isothermal dry operation, the outdoor fan 8 is operated at a rotation speed N = 150 rpm. In this case, the amount of heat radiated by the reheater (the indoor heat exchanger 5) is reduced by the amount of the heat radiated by the refrigerant in the outdoor heat exchanger 3, and the dry air is blown into the room to such an extent that it is warmed to the same temperature as the room temperature Ta. .

When the room temperature Ta is high, the cool dry operation is selected. In this cool dry operation, the outdoor fan 8 is operated at a rotation speed N = 200 rpm to a rotation speed N = 400 rpm. In this case, the amount of heat radiation of the reheater (indoor heat exchanger 5) decreases as much as the amount of heat radiation of the refrigerant in the outdoor heat exchanger 3 increases, and the dry air is blown into the room in a cold state without being heated much. Is done.

As described above, by controlling the number of revolutions N of the outdoor fan 8 to adjust the temperature of the dry air, it is possible to moderate the fluctuation of the indoor temperature, which is comfortable.

In the dry operation, as shown in FIG. 8, the indoor heat exchange functioning as an evaporator during the isothermal dry operation and the cool dry operation in which the rotational speed N of the outdoor fan 8 becomes N ₁ (= 150 rpm) or more. The degree of opening of the PMV 6 is controlled such that the degree of superheating of the refrigerant in the heater 5 (= detection temperature of the temperature sensor 15−detection temperature of the temperature sensor 14) becomes a constant value. Thereby, stable and appropriate dehumidifying ability is secured.

However, the rotational speed N of the outdoor fan 8 is N
_{In the} warm dry operation of ₁ (= 150 rpm) or less, the constant value control of the refrigerant superheat degree is prohibited, and the PMV 6 is maintained at a constant opening degree.

Generally, in the warm dry operation, when the superheat degree constant value control is performed, the refrigerant of the reheater almost reaches the supercooling region, the heating capacity of the reheater decreases, and the evaporator capacity becomes equal or increases. Therefore, the warming ability is rather reduced. That is, as shown in FIG. 9, even if the operating frequency F of the compressor 1 increases, the amount of sensible heat does not increase so much. Moreover, in the superheat constant value control at the time of warm-drying, the difference between the high and low pressures of the refrigeration cycle increases, the compressor load increases, and the power consumption increases.

In order to solve these problems, the PMV 6 is maintained at a constant opening as described above, so that comfortable air conditioning and energy saving effects can be obtained.

When the operation is started from a stop, as shown in FIG. 10, the PMVs 4 and 6 are initialized when the power is turned on. This initialization is to adjust the opening of PMV4,6 properly.
The PMVs 4 and 6 are once fully closed and then brought to the opening required for operation.

When switching from the cooling operation to the dry operation, the PMV 4 shifts from the throttled state to the fully opened state,
The MV 6 shifts from the fully opened state to the throttled state. At that time, there is a concern that loud refrigerant noise may be generated due to pressure fluctuation.

Therefore, in a situation where the pressure fluctuation of the refrigerant is large, such as when switching from the cooling operation to the dry operation, the PMV4,
6 slows down the opening change. For example, the number of drive pulses supplied to the PMVs 4 and 6 is suppressed to about 10 pulses per second.

In a situation where the change in pressure of the refrigerant is not so large as during operation, it is not necessary to slow down the change in the opening of the PMVs 4 and 6, for example, the number of drive pulses supplied to the PMVs 4 and 6 is reduced to 30 per second. It is about a pulse.

On the other hand, at the time of initialization, the compressor 1 is not yet operated and no refrigerant noise is generated, and the driving noise of the PMVs 4 and 6 is not prolonged.
The opening degree change of 4, 6 is made faster. For example, PMV4,6
Is 100 pulses per second.

In the above-described embodiment, the PMV 6 is maintained at a constant opening during warm drying, but the opening of the PMV 6 may be maintained at a constant opening corresponding to the operating frequency F of the compressor 1. Similar effects can be obtained. FIG. 9 shows the change in the sensible heat amount in this case, and FIG. 11 shows the relationship between the operating frequency F and the constant opening. That is, the operation frequency F is set by the command code S sent from the indoor unit to the outdoor unit, and at the same time, the constant opening of the PMV 6 is set.

At the time of warm drying, the temperature of the indoor heat exchanger 7 as an evaporator (that is, the evaporating temperature) is detected by the temperature sensor 15, and the PMV 6 is controlled so that the detected temperature becomes a constant value (for example, 5 ° C to 10 ° C). The same effect can be obtained by controlling the opening degree of.

In this case, the opening of the PMV 6 may be controlled so that the evaporation temperature is maintained at a predetermined value corresponding to the operating frequency F of the compressor 1. FIG. 12 shows the relationship between the operating frequency F and the evaporation temperature in this case. That is, when the operation frequency F is set by the command code S sent from the indoor unit to the outdoor unit, the evaporation temperature corresponding to the operation frequency F is read, and the temperature sensor 1
The opening degree of the PMV 6 is controlled so that the detected temperatures 5 coincide.

At the time of warm drying, the temperature of the indoor heat exchanger 5 (that is, the condensing temperature), which is a reheater, is detected by the temperature sensor 16, and the detected temperature is a constant value (for example, 30 ° C. to 35 ° C.).
The same effect can be obtained by controlling the opening of the PMV 6 such that

In this case, the opening of the PMV 6 may be controlled so that the condensing temperature is maintained at a predetermined value corresponding to the operating frequency F of the compressor 1. FIG. 13 shows the relationship between the operating frequency F and the condensation temperature in this case. That is, when the operating frequency F is set by the command code S sent from the indoor unit to the outdoor unit, the condensing temperature corresponding to the operating frequency F is read, and the temperature sensor 1
The opening degree of the PMV 6 is controlled so that the detected temperatures 5 coincide.

In the above embodiment, the pressure reducer is P
Although the MVs 4 and 6 are used, an expansion mechanism with a variable throttle amount including a capillary and an on-off valve may be used instead.

[0082]

As described above, according to the present invention, the air conditioner of the first aspect controls the number of rotations of the outdoor fan in accordance with the indoor temperature during the dry operation, so that the temperature of the dry air is different. Since the configuration is such that the mild dry, the isothermal dry, and the warm dry are selectively executed, the fluctuation in the room temperature during the dry operation can be moderated, and the comfort can be improved.

In the air conditioner of the second aspect, the opening degree of the second electronic expansion valve is controlled so that the degree of superheat of the refrigerant in the second indoor heat exchanger functioning as an evaporator becomes constant during the cold-dry and the isothermal drying. , And the second electronic expansion valve is maintained at a constant opening during warm drying, so that stable and appropriate dehumidifying ability is always ensured during dry operation, and comfortable air conditioning and energy saving effects can be obtained. .

In the air conditioner of the third aspect, the opening degree of the second electronic expansion valve is controlled such that the degree of superheat of the refrigerant in the second indoor heat exchanger functioning as an evaporator becomes constant during the cold-dry and the isothermal drying. And controlling the opening of the second electronic expansion valve so that the temperature of the first indoor heat exchanger (condensation temperature) or the temperature of the second indoor heat exchanger (evaporation temperature) becomes a constant value during the warm-dry time. With such a configuration, stable and appropriate dehumidifying ability during dry operation is always ensured, and comfortable air conditioning and energy saving effects can be obtained.

In the air conditioner of the fourth aspect, the opening degree of the second electronic expansion valve is controlled so that the degree of superheat of the refrigerant in the second indoor heat exchanger functioning as an evaporator becomes constant during the cold-dry and the isothermal drying. The second electronic expansion valve is maintained at a constant opening in accordance with the capacity of the compressor when warm and dry, so that stable and appropriate dehumidifying capacity during dry operation is always ensured for comfortable air conditioning. And an energy saving effect is obtained.

In the air conditioner of the fifth aspect, the opening degree of the second electronic expansion valve is controlled so that the degree of superheat of the refrigerant in the second indoor heat exchanger functioning as an evaporator becomes constant during the cold and isothermal drying. The second electronic expansion valve so that the temperature of the first indoor heat exchanger (condensation temperature) or the second indoor heat exchanger (evaporation temperature) becomes a constant value according to the capacity of the compressor during warm drying. , The stable and appropriate dehumidifying capacity during dry operation is always ensured, and comfortable air conditioning and energy saving effects can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a refrigeration cycle according to an embodiment of the present invention.

FIG. 2 is an internal configuration diagram of the indoor unit in the embodiment.

FIG. 3 is a diagram showing a general drain discharge configuration of an indoor heat exchanger.

FIG. 4 is a diagram showing a drain discharge configuration of the indoor heat exchanger in the embodiment.

FIG. 5 is a configuration diagram of a modified example of FIG. 4;

FIG. 6 is a diagram showing a state before bending of the indoor heat exchanger of FIG. 5;

FIG. 7 is a format of a frequency / rotational number allocation condition for a dry machine according to the embodiment;

FIG. 8 is a flowchart for explaining constant superheat degree value control during a dry operation in the embodiment.

FIG. 9 is a diagram showing a relationship between an operating frequency F and a sensible heat amount in the embodiment.

FIG. 10 is a time chart showing an example of a change in the opening degree of PMVs 4 and 6 in the embodiment.

FIG. 11 shows a format of opening control of PMV6 in another embodiment of the present invention.

FIG. 12 shows a format of evaporation temperature constant control by PMV6 in still another embodiment.

FIG. 13 is a format of constant condensing temperature control by PMV6 in another embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... 4-way valve, 3 ... Outdoor heat exchanger, 4 ... PM
V (first electronic expansion valve), 5: first indoor heat exchanger, 6: P
MV (second electronic expansion valve), 7 ... second indoor heat exchanger, 8 ...
Outdoor fan, 9: indoor fan, 20: control unit.

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[Procedure amendment]

[Submission Date] September 25, 2001 (2001.9.2)
5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Deleted

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005] The present invention has been made in view of the above circumstances ,
It is an object of the present invention to provide an air conditioner that can moderate fluctuations in room temperature during a dry operation and improve comfort.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Deleted

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007]

In the air conditioner according to the first aspect of the present invention , the indoor heat exchanger includes a cooling / dehumidifying portion and a heating portion.
And the air volume of the fan of the outdoor heat exchanger during dry operation
Of compressor and compressor capacity and airflow of fan of indoor heat exchanger
By controlling the heating capacity of the heating part, outdoor heat exchanger
Control the amount of heat radiation.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

[0008] An air conditioner according to a second aspect of the present invention is an indoor air conditioner.
Cooling / dehumidifying part and heating part where heat exchanger is thermally divided
And provided between the cooling / dehumidifying portion and the heating portion.
A second expansion mechanism provided by the indoor temperature sensor.
Control means for inputting the detected room temperature.
The control means controls the fan of the outdoor heat exchanger.
Airflow, compressor capacity, and indoor heat exchanger fan airflow
By controlling the amount, cool dry, isothermal dry, warm dry
Perform each dry operation control of b.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

An air conditioner according to a third aspect of the present invention is an indoor air conditioner.
The heat exchanger has a cooling / dehumidifying part and a heating part.
Input the room temperature detected by the room temperature sensor.
Control means for controlling the detected room temperature and the set temperature.
When it is determined that the difference from
Reduce the heat radiation of the heat exchanger to increase the heating capacity of the heating part.
The operation is controlled so as to increase.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

[0010] The air conditioner of the invention according to claim 4 is an indoor air conditioner.
The heat exchanger has a dry function consisting of a cooler and a heater
Controlling the number of revolutions of the outdoor fan motor
Means, and means for controlling the number of revolutions of the compressor,
It controls the rotation speed of the outer fan motor and the compressor
Control the internal temperature and dehumidification capacity.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

[0011] air conditioner of the invention according to claim 5, wherein
The invention according to claim 1 or 2, further comprising:
A temperature sensor is provided, and the temperature is detected by the indoor temperature sensor.
Compare the detected room temperature with the set room temperature, and
Cold when dry, isothermal when both are roughly equal
Dry, warm dry when the detection room temperature is lower
I am able to drive. The sky of the invention according to claim 6
The air conditioner divides the indoor heat exchanger into two parts and dehumidifies between them
The compressor has a cycle configuration with a throttle device.
Equipped with a compressor that can change the number of turns,
And at least one of the outdoor fan motors
Humidity detector that detects the indoor humidity by mounting a motor
A step is provided to respond to the indoor humidity detected by the indoor humidity detecting means.
The number of revolutions of the compressor is changed accordingly. Claim 7
The air conditioner according to the invention according to the first aspect includes a first indoor heat exchanger and a second indoor heat exchanger.
A cycle equipped with a dehumidifying operation throttle device between the internal heat exchanger
An indoor temperature sensor that has a
Indoor humidity sensor to detect indoor humidity and compressor rotation
The number of rotations of the indoor fan motor and the outdoor fan motor.
Control means for controlling the room temperature and the setting.
According to the difference between the constant temperature and the difference between the indoor humidity and the set humidity
The rotation speed of the compressor during dry operation, the rotation speed of the indoor fan,
The number of rotations of the outdoor fan is stored, and is
Difference between the detected room temperature and the set temperature and the room humidity
And the difference between the indoor humidity detected by the sensor and the set humidity
The number of rotations of the compressor, the number of rotations of the indoor fan,
The number of rotations of the compressor according to the number of rotations of the outdoor fan,
Controls the fan speed and the outdoor fan speed. Claim
The air conditioner according to the invention according to claim 8 is the air conditioner according to claim 7,
During the dry operation stored in the control means
The number of rotations of the compressor is limited.
Is the difference between the room temperature and the set temperature
The room increases as the negative value increases.
The larger the difference between the internal humidity and the set humidity, the larger
It is set to become. The sky of the invention according to claim 9
An air conditioner according to claim 7 or claim 8 is provided.
The room for the dry operation stored in the control means.
The number of rotations of the inner fan is limited.
Is the difference between the room temperature and the set temperature
The room increases as the negative value increases.
The larger the difference between the internal humidity and the set humidity, the larger
It is set to become. The invention according to claim 10
An air conditioner according to the ninth aspect of the present invention is the indoor fan.
The number of rotations of the
Is in the area where the difference between the room temperature and the set temperature is far,
Smaller value for the same absolute value difference on the negative side than on the positive side
Is set to An air conditioner according to claim 11.
The invention according to any one of claims 7 to 10
In addition, the number of rotations of the outdoor fan is limited,
At this rotation speed, the difference between the room temperature and the set temperature increases.
Is set to be larger in accordance with

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

As shown in FIG. 1, a discharge port of the compressor 1
The outdoor heat exchanger 3 is connected via the four-way valve 2. This outdoor heat exchanger 3 is used as an expansion mechanism such as a dehumidifying throttle device.
Is connected to the first indoor heat exchanger 5 via the first electronic expansion valve 4 that functions as a heat exchanger. The first indoor heat exchanger 5 is connected to a second indoor heat exchanger 7 via a variable expansion mechanism such as a second electronic expansion valve 6, and the second indoor heat exchanger 7 is connected to the four-way valve 2.
To the suction port of the compressor 1.

[Procedure amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

The compressor 1 is a variable capacity ( variable rotational speed) compressor, and a drive motor is connected to an inverter circuit 11. The inverter circuit 11 rectifies the voltage of the commercial AC power supply 10, converts the rectified voltage into AC having a frequency corresponding to a command from the control unit 20, and outputs the AC. This output is the driving power of the compressor motor.

[Procedure amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

An outdoor fan (outdoor outdoor) is provided near the outdoor heat exchanger 3.
A heat exchanger fan 8 is provided. This outdoor fan 8
The motor 8 circulates outside air to the outdoor heat exchanger 3.
M is connected to the phase control circuit 12. The phase control circuit 12 performs phase control of energization from the commercial AC power supply 10 to the motor 8M according to a command from the control unit 20. By this phase control, the rotation speed of the outdoor fan 8 can be changed.

[Procedure amendment 13]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction contents]

An indoor fan is provided near the indoor heat exchangers 5, 7.
(Fan of indoor heat exchanger) 9 is provided. The indoor fan 9 circulates indoor air through the indoor heat exchangers 5 and 7, and a motor 9M is connected to a commercial AC power supply 10 via a tap switching circuit 13. The tap switching circuit 13 includes speed switching taps H (high speed), M (medium speed), L (low speed), L-
(Very low speed) and UL (ultra low speed), and performs tap switching according to a command from the control unit 20.

[Procedure amendment 14]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction contents]

It should be noted that the indoor heat exchangers 7 and 5 having such an integral structure can be used during the dry operation to be described later.
(= Evaporator ; cooler ) drain generated in the indoor heat exchanger 5
(= Reheater ; heater ), which evaporates in the indoor heat exchanger 5 and is blown out into the room, which may cause a decrease in dehumidification performance.

[Procedure amendment 15]

[Document name to be amended] Statement

[Correction target item name] 0045

[Correction method] Change

[Correction contents]

That is, the drain generated on the upper side of the indoor heat exchanger 7 flows along the slot 40 and the connecting piece 42 and is guided downward without dripping on the lower side of the indoor heat exchanger 5. Therefore, a decrease in dehumidifying performance is prevented.
In addition , the presence of the connecting piece 42 eliminates useless ventilation at the bent portion, and improves the heat exchange efficiency.

[Procedure amendment 16]

[Document name to be amended] Statement

[Correction target item name] 0058

[Correction method] Change

[Correction contents]

At the time of this dry operation, the operating frequency F of the compressor 1 and the indoor fan 9 are determined based on the predetermined frequency and rotation number allocation conditions for drying shown in FIG. 7 and the detected indoor temperature Ta and set humidity Ha. Is set. Figure
7 is assigned to the internal memo of the control unit 20.
Is stored in the memory.

[Procedure amendment 17]

[Document name to be amended] Statement

[Correction target item name] 0066

[Correction method] Change

[Correction contents]

As described above, by controlling the number of revolutions N of the outdoor fan 8 to adjust the temperature of the dry air, it is possible to moderate the fluctuation of the indoor temperature, which is comfortable. What
Note that the frequency and rotation number allocation conditions for the dry in FIG.
Can be expressed as follows. Compressor 1 during dry operation
The operating frequency F (rotational speed) of the vehicle is the room temperature Ta and the set temperature.
Positive and negative values increase with the difference from Ts centered at 0
And the room humidity Ha and the set humidity
So that the difference from the degree Hs increases
Is set to The number of rotations of the indoor fan 9 is the indoor temperature.
The difference between Ta and the set temperature Ts is positive and negative around 0.
As the value increases, it increases and the indoor humidity increases.
As the difference between the degree Ha and the set humidity Hs increases,
The room temperature Ta is set to
In the region where the difference from the constant temperature Ts is far away, the negative side is more than the positive side.
Is set to a smaller value for the same absolute value difference.
You. The rotational speed N of the outdoor fan 8 is determined by the indoor temperature Ta and the set temperature.
So that the difference from the degree Ts increases
Is set to

[Procedure amendment 18]

[Document name to be amended] Statement

[Correction target item name]

[Correction method] Change

[Correction contents]

[0082]

As described above, according to the present invention, the fluctuation in the room temperature during the dry operation can be moderated, and the comfort can be improved.

[Procedure amendment 19]

[Document name to be amended] Statement

[Correction target item name] 0083

[Correction method] Deleted

[Procedure amendment 20]

[Document name to be amended] Statement

[Correction target item name]

[Correction method] Deleted

[Procedure amendment 21]

[Document name to be amended] Statement

[Correction target item name] 0085

[Correction method] Deleted

[Procedure amendment 22]

[Document name to be amended] Statement

[Correction target item name] 008

[Correction method] Deleted

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takao Hoshi 336 Tatehara, Fuji City, Shizuoka Prefecture Inside Fuji Plant, Toshiba Corporation (72) Inventor Hideaki Suzuki 336 Tatehara Field, Fuji City, Shizuoka Prefecture Inside Fuji Plant, Toshiba Corporation (72) Inventor Yoshitaka Strashina 336 Tatehara, Fuji-shi, Shizuoka Prefecture Inside Fuji Plant, Toshiba Corporation (72) Inventor Megumi Komasaki 336 Tatehara, Fuji City, Shizuoka Prefecture Inside Fuji Plant Toshiba Corporation (72) Inventor Nobuo Kawai Fuji City, Shizuoka Prefecture 336 Tatehara F-term in Toshiba Corporation Fuji Plant (Reference) 3L060 AA07 CC02 CC07 DD05 EE06 EE09

Claims (5)

[Claims] 1. A compressor, an outdoor heat exchanger, an expansion mechanism, a first
A refrigeration cycle to which an indoor heat exchanger, an expansion mechanism with a variable throttle amount, and a second indoor heat exchanger are connected, an outdoor fan that circulates outdoor air through the outdoor heat exchanger, and a refrigerant that is discharged from the compressor. The heat exchanger, the expansion mechanism, the first indoor heat exchanger, the expansion mechanism with a variable throttle amount, and the second indoor heat exchanger are flowed through and the expansion mechanism is narrowed to fully open the expansion mechanism with a variable throttle amount to execute the cooling operation. Means for performing refrigerant discharge from the compressor, an outdoor heat exchanger, an expansion mechanism, a first indoor heat exchanger,
An expansion mechanism with a variable throttle amount, means for flowing through the second indoor heat exchanger and fully opening the expansion mechanism to narrow the expansion mechanism with a variable throttle amount to perform a dry operation; an indoor temperature sensor for detecting an indoor temperature; During dry operation, means for controlling the number of rotations of the outdoor fan according to the detected temperature of the indoor temperature sensor, and selectively performing cold dry, isothermal dry, warm dry in which the temperature of dry air is different. An air conditioner, comprising: 2. A refrigeration cycle connecting a compressor, an outdoor heat exchanger, a first electronic expansion valve, a first indoor heat exchanger, a second electronic expansion valve, and a second indoor heat exchanger, and the outdoor heat exchanger. An outdoor fan for circulating outdoor air to the outdoor heat exchanger, a first electronic expansion valve, a first indoor heat exchanger, a second electronic expansion valve, and a second indoor heat exchanger. Means for flowing cooling air through the first electronic expansion valve and fully opening the second electronic expansion valve to execute a cooling operation; and an outdoor heat exchanger, a first electronic expansion valve, and a first electronic expansion valve for discharging the refrigerant discharged from the compressor. Means for flowing through the indoor heat exchanger, the second electronic expansion valve, and the second indoor heat exchanger, and for fully opening the first electronic expansion valve, narrowing the second electronic expansion valve and executing a dry operation, and detecting the indoor temperature The outdoor temperature according to the temperature detected by the indoor temperature sensor during the dry operation. Means for controlling the number of rotations of the fan, and selectively performing cold dry, isothermal dry, and warm dry with different dry air temperatures; Means for controlling the degree of opening of the second electronic expansion valve so that the degree of superheating of the refrigerant becomes a constant value, and means for maintaining the degree of opening of the second electronic expansion valve at a constant degree of opening during warm drying. And air conditioner. 3. A refrigeration cycle connecting a compressor, an outdoor heat exchanger, a first electronic expansion valve, a first indoor heat exchanger, a second electronic expansion valve, and a second indoor heat exchanger, and the outdoor heat exchanger. An outdoor fan for circulating outdoor air to the outdoor heat exchanger, a first electronic expansion valve, a first indoor heat exchanger, a second electronic expansion valve, and a second indoor heat exchanger. Means for flowing cooling air through the first electronic expansion valve and fully opening the second electronic expansion valve to execute a cooling operation; and an outdoor heat exchanger, a first electronic expansion valve, and a first electronic expansion valve for discharging the refrigerant discharged from the compressor. Means for flowing through the indoor heat exchanger, the second electronic expansion valve, and the second indoor heat exchanger, and for fully opening the first electronic expansion valve, narrowing the second electronic expansion valve and executing a dry operation, and detecting the indoor temperature The outdoor temperature according to the temperature detected by the indoor temperature sensor during the dry operation. Means for controlling the number of rotations of the fan, and selectively performing cold dry, isothermal dry, and warm dry with different dry air temperatures; Means for controlling the degree of opening of the second electronic expansion valve so that the degree of superheat of the refrigerant becomes a constant value, and the temperature of the first indoor heat exchanger or the second indoor heat exchanger becomes a constant value during warm drying. Means for controlling the opening of the second electronic expansion valve as described above. 4. A refrigeration cycle connecting a compressor, an outdoor heat exchanger, a first electronic expansion valve, a first indoor heat exchanger, a second electronic expansion valve, and a second indoor heat exchanger, and the outdoor heat exchanger. An outdoor fan for circulating outdoor air to the outdoor heat exchanger, a first electronic expansion valve, a first indoor heat exchanger, a second electronic expansion valve, and a second indoor heat exchanger. Means for flowing cooling air through the first electronic expansion valve and fully opening the second electronic expansion valve to execute a cooling operation; and an outdoor heat exchanger, a first electronic expansion valve, and a first electronic expansion valve for discharging the refrigerant discharged from the compressor. Means for flowing through the indoor heat exchanger, the second electronic expansion valve, and the second indoor heat exchanger, and for fully opening the first electronic expansion valve, narrowing the second electronic expansion valve and executing a dry operation, and detecting the indoor temperature The outdoor temperature according to the temperature detected by the indoor temperature sensor during the dry operation. Means for controlling the number of rotations of the fan, and selectively performing cold dry, isothermal dry, and warm dry with different dry air temperatures; Means for controlling the opening of the second electronic expansion valve so that the degree of superheat of the refrigerant becomes a constant value, and maintaining the second electronic expansion valve at a constant opening in accordance with the capacity of the compressor during warm drying. And an air conditioner. 5. A refrigeration cycle connecting a compressor, an outdoor heat exchanger, a first electronic expansion valve, a first indoor heat exchanger, a second electronic expansion valve, and a second indoor heat exchanger, and the outdoor heat exchanger. An outdoor fan for circulating outdoor air to the outdoor heat exchanger, a first electronic expansion valve, a first indoor heat exchanger, a second electronic expansion valve, and a second indoor heat exchanger. Means for flowing cooling air through the first electronic expansion valve and fully opening the second electronic expansion valve to execute a cooling operation; and an outdoor heat exchanger, a first electronic expansion valve, and a first electronic expansion valve for discharging the refrigerant discharged from the compressor. Means for flowing through the indoor heat exchanger, the second electronic expansion valve, and the second indoor heat exchanger, and for fully opening the first electronic expansion valve, narrowing the second electronic expansion valve and executing a dry operation, and detecting the indoor temperature The outdoor temperature according to the temperature detected by the indoor temperature sensor during the dry operation. Means for controlling the number of rotations of the fan, and selectively performing cold dry, isothermal dry, and warm dry with different dry air temperatures; Means for controlling the degree of opening of the second electronic expansion valve so that the degree of superheat of the refrigerant becomes a constant value, and when the temperature of the first indoor heat exchanger or the second indoor heat exchanger is low, Means for controlling the degree of opening of the second electronic expansion valve so as to have a constant value corresponding to the capacity.