JPH10306949A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a multi-room split type air conditioner for suitably and efficiently operating without lowering an efficiency of a refrigerating cycle even when non-azeotrope refrigerant is used as refrigerant. SOLUTION: The multi-room split type air conditioner comprises a refrigerant circuit using as refrigerant non-azeotrope refrigerant to supply it from a compressor 1 to a vapor-liquid separator 5 via an outdoor heat exchanger 2 operating as a condenser, to separate gas refrigerant separated by the separator 5 via a first indoor heat exchanger 3 operating as a condenser and first pressure- reducing means 6, to combine it with liquid refrigerant fed through a third pressure-reducing means 8, and to return it to the compressor 1 via a second pressure reducing means 7 and a second indoor side heat exchanger 4 operating as an evaporator. And, dryness altering means 19 to 24 for pouring the liquid refrigerant in the gas refrigerant flowing to the exchanger 3 to refrigerant of vapor-liquid two-phase state are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an outdoor unit in which a plurality of indoor units are connected in parallel to one outdoor unit, and cooling and heating are selectively performed for each indoor unit. ,
The present invention relates to a multi-room air conditioner having a refrigerant circuit in which heating can be simultaneously performed in the other indoor unit and a non-azeotropic mixed refrigerant is used as a refrigerant.

[0002]

2. Description of the Related Art FIG.
FIG. 5 is a schematic configuration diagram illustrating a refrigerant circuit in a conventional multi-room air conditioner at the time of simultaneous cooling-heating and heating operations in a conventional multi-chamber air conditioner described in Japanese Patent Publication No. 5 (JP-A) No. 5; In the figure, 1 is a compressor, 2 is an outdoor heat exchanger that operates as a condenser, 3 is a first indoor heat exchanger that operates as a condenser, 4 is a second indoor heat exchanger that operates as an evaporator, 5 is a gas-liquid separator, 6 is a first decompression means, 7
Is a second pressure reducing means, 8 is a third pressure reducing means, and 9 to 18 are refrigerant pipes.

Next, the operation will be described. The high-temperature and high-pressure refrigerant discharged from the compressor 1 flows into the outdoor heat exchanger 2 through the discharged refrigerant pipe 9, where it exchanges heat with outdoor air to be cooled, condensed to a certain degree of dryness, and is in a gas-liquid two-phase state. And flows into the gas-liquid separator 5 through the refrigerant pipe 10. Gas-liquid separator 5
, The refrigerant is divided into a liquid refrigerant and a gas refrigerant, and the gas refrigerant flows through the refrigerant pipe 11 and is condensed in the first indoor heat exchanger 3 until it is supercooled. The pressure is reduced by the means 6 to become a liquid refrigerant. The liquid refrigerant separated by the gas-liquid separator 5 is slightly depressurized by the third decompression means 8 via the bypass refrigerant pipe 14 and then transmitted from the first indoor heat exchanger 3 and the first decompression means 6. With the liquid refrigerant. The merged liquid refrigerant flows through the refrigerant pipe 16 into the second decompression means 7, where it is decompressed to a low pressure and evaporated in the second indoor heat exchanger 4, and then becomes a gas refrigerant and becomes a refrigerant pipe 18
To return to the compressor 1.

[0004]

In a conventional multi-chamber air conditioner as described above, when a non-azeotropic mixed refrigerant is used as the refrigerant, the liquid refrigerant separated in the gas-liquid separator 5 is not used. The composition of the gas refrigerant changes according to the temperature under the same pressure,
The efficiency of the air conditioner is reduced, the target capacity is not obtained in the indoor unit, and the supercooling degree or superheat degree of the target refrigerant is not obtained at the outlet of the indoor heat exchanger, There have been problems such as the reliability of the refrigeration cycle being impaired due to noise and liquid return to the compressor.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. Even if a non-azeotropic mixed refrigerant is used as the refrigerant, the efficiency of the refrigeration cycle does not decrease, and the target for each indoor unit is reduced. And a multi-room air conditioner that can operate the refrigeration cycle properly and efficiently by setting the refrigerant state at the outlet of each indoor heat exchanger to the target degree of supercooling or superheat. The purpose is to gain.

[0006]

The air conditioner according to claim 1 of the present invention uses a non-azeotropic mixed refrigerant as a refrigerant,
In an air conditioner provided with a refrigerant circuit that returns from the compressor to the condenser, the decompression means, and the evaporator to the compressor, the heat exchanger of at least one of the condenser and the evaporator has a degree of dryness of the refrigerant. A means for changing dryness is provided.

A multi-room air conditioner according to a second aspect of the present invention has a plurality of indoor heat exchangers and a gas-liquid separator, and uses the gas refrigerant separated by the gas-liquid separator to heat the indoor heat exchanger. In the multi-room air conditioner that performs a simultaneous cooling and heating operation with a refrigerant circuit that uses a non-azeotropic mixed refrigerant as a refrigerant, the liquid refrigerant flows into the cooling indoor heat exchanger, and flows into the heating indoor heat exchanger. A dryness changing means is provided by injecting a liquid refrigerant into a gas refrigerant to convert the refrigerant into a gas-liquid two-phase refrigerant.

According to a third aspect of the present invention, a multi-chamber air conditioner uses a non-azeotropic mixed refrigerant as a refrigerant, flows from a compressor to an outdoor heat exchanger, and flows into a gas-liquid separator. The gas refrigerant separated by the separator is supplied to the first indoor heat exchanger and the first indoor heat exchanger.
And the liquid refrigerant separated by the gas-liquid separator and passed through the third decompression means, and then returned to the compressor via the second decompression means and the second indoor heat exchanger. In a multi-room air conditioner provided with a circuit, a dryness changing means is provided, in which a liquid refrigerant is injected into a gas refrigerant flowing into the first indoor heat exchanger to convert the gas refrigerant into a gas-liquid two-phase state refrigerant. .

A multi-room air conditioner according to a fourth aspect of the present invention is the multi-room air conditioner according to the third aspect of the present invention, wherein
A hole through which the liquid refrigerant in the gas-liquid separator flows is provided in the middle of the pipe connecting the indoor heat exchanger.

[0010] According to a fifth aspect of the present invention, in the multi-chamber air conditioner according to the third aspect, the gas-liquid separator and the first air conditioner are connected to each other.
In the middle of the gas refrigerant pipe connecting the indoor heat exchanger, the liquid refrigerant is sucked up from the liquid refrigerant pipe connecting the gas-liquid separator and the third decompression means via the gas-liquid mixing pipe, and And a gas-liquid mixing section for mixing the gas refrigerant.

According to a sixth aspect of the present invention, there is provided a multi-room air conditioner comprising: an outdoor unit having a variable displacement compressor, a four-way valve, and an outdoor heat exchanger; an indoor heat exchanger and first flow control means, respectively. Are connected by two refrigerant pipes of the indoor unit, the outdoor unit, the high-pressure refrigerant pipe, and the low-pressure refrigerant pipe,
The air conditioner further includes a branch controller connected to each of the first flow control unit and the medium-pressure refrigerant pipe by the indoor heat exchangers and the gas refrigerant pipes of the plurality of indoor units, and the branch controller is connected to the outdoor unit. A gas-liquid separator that separates the refrigerant from the high-pressure refrigerant pipe into a high-pressure gas refrigerant pipe and a high-pressure liquid refrigerant pipe,
Second flow control means connected between the plurality of medium-pressure refrigerant pipes connected to the indoor unit, and connection between the low-pressure refrigerant pipe connected to the outdoor unit and the plurality of medium-pressure refrigerant pipes Third flow control means, a first switching on-off valve for selectively connecting an output high-pressure gas refrigerant pipe of the gas-liquid separator and a plurality of gas refrigerant pipes connected to the indoor unit, and the outdoor A second switching valve that selectively connects a low-pressure refrigerant pipe connected to the unit and a plurality of gas refrigerant pipes connected to the indoor unit, and further includes a non-azeotropic mixed refrigerant as a refrigerant. In the multi-chamber air conditioner used, in the middle of a refrigerant pipe connecting the output high-pressure gas refrigerant pipe of the gas-liquid separator and the plurality of second switching valves, the output high-pressure liquid of the gas-liquid separator is provided. From the refrigerant pipe to the gas-liquid mixing pipe,
A gas-liquid mixing section is provided which sucks up liquid refrigerant via an on-off valve opened during simultaneous cooling and heating operations mainly for cooling and mixes with the gas refrigerant in the output high-pressure gas refrigerant pipe of the gas-liquid separator.

A multi-chamber air conditioner according to a seventh aspect of the present invention is the multi-room air conditioner according to the sixth aspect, wherein the multi-room air conditioner branches off from a high-pressure or medium-pressure refrigerant pipe upstream or downstream of the second flow control means of the branch controller. A bypass flow path to a low-pressure refrigerant pipe via a bypass flow rate control means and a supercooling heat exchanger that exchanges heat with a plurality of medium-pressure refrigerant pipes and a high-pressure liquid refrigerant pipe.

The multi-chamber air conditioner according to an eighth aspect of the present invention is the multi-room air conditioner according to the seventh aspect, wherein the first temperature detecting means detects a refrigerant temperature upstream of the bypass flow rate control means,
Second temperature detecting means for detecting the refrigerant temperature downstream of the bypass flow rate control means, first pressure detecting means for detecting the refrigerant pressure downstream of the bypass flow rate control means, and second pressure for detecting the discharge pressure of the compressor Detecting means, third pressure detecting means for detecting the suction pressure of the compressor, the first and second temperature detecting means, and refrigerant for calculating the composition of the refrigerant from the detected values of the first pressure detecting means A compressor / outdoor for controlling the operating frequency of the compressor and the number of rotations of the outdoor fan in accordance with a composition calculation device, a calculation value of the refrigerant composition calculation device, and a detection value of the second and third pressure detection means. A fan control device is provided.

According to a ninth aspect of the present invention, in the multi-room air conditioner according to the seventh aspect, a first temperature detecting means for detecting a refrigerant temperature upstream of the bypass flow control means,
A second temperature detecting means for detecting a refrigerant temperature downstream of the bypass flow rate control means, a third temperature detecting means for detecting a high pressure refrigerant temperature upstream of the second flow rate control means, and a refrigerant pressure downstream of the bypass flow rate control means. First pressure detecting means for detecting;
Fifth pressure detecting means for detecting the output high-pressure refrigerant pressure of the gas-liquid separator, refrigerant for calculating the composition of the refrigerant from the detection values of the first and second temperature detecting means, and the first pressure detecting means A controller for controlling the degree of opening of the second flow rate control means in accordance with the composition calculation device, the calculation value of the refrigerant composition calculation device, and the detection values of the fifth pressure detection means and the third temperature detection means. Are provided.

According to a tenth aspect of the present invention, in the multi-room air conditioner according to the sixth aspect, a fourth pressure detecting means for detecting a refrigerant pressure of the medium-pressure refrigerant pipe; Fifth pressure detecting means for detecting the output high-pressure refrigerant pressure;
A controller for controlling the opening of the third flow control means in accordance with the detection values of the fourth pressure detection means and the fifth pressure detection means is provided.

[0016] According to an eleventh aspect of the present invention, in the multi-room air conditioner according to the seventh aspect, a fourth pressure detecting means for detecting a refrigerant pressure of the medium-pressure refrigerant pipe, and a gas-liquid separator. Fifth pressure detecting means for detecting the output high-pressure refrigerant pressure;
Second temperature detecting means for detecting the temperature of the refrigerant downstream of the bypass flow rate control means, fourth temperature detecting means for detecting the temperature of the refrigerant downstream of the subcooling heat exchanger in the bypass line, and the fourth pressure detecting means , A fifth pressure detecting means, a second temperature detecting means, and a controller for controlling an opening degree of the bypass flow rate controlling means in accordance with a detection value of the fourth temperature detecting means.

According to a twelfth aspect of the present invention, in the multi-room air conditioner according to the seventh aspect of the present invention, the fifth aspect detects the refrigerant temperature between the indoor heat exchanger and the first flow rate control means. Temperature detecting means, sixth temperature detecting means for detecting the refrigerant temperature of the gas refrigerant pipe connected to the indoor heat exchanger, fifth pressure detecting means for detecting the output high-pressure refrigerant pressure of the gas-liquid separator, According to the detected values of the fifth temperature detecting means and the sixth temperature detecting means, or the detected values and the saturated temperature value of the high-pressure refrigerant pressure value detected by the fifth pressure detecting means,
And a controller for controlling the opening of the flow rate control means.

According to a thirteenth aspect of the present invention, in the multi-room air conditioner according to the eighth or ninth aspect, the operation value of the refrigerant composition operation device is calculated according to the capacity ratio between the cooling and the heating of the indoor unit. It is to be corrected.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a schematic configuration diagram showing a refrigerant circuit at the time of simultaneous cooling / heating operation mainly in cooling according to Embodiment 1 of the present invention. In FIG. A first indoor heat exchanger that operates as a condenser, 4 is a second indoor heat exchanger that operates as an evaporator, 5 is a gas-liquid separator, 6 is first decompression means, and 7 is second decompression means. , 8 are third pressure reducing means, and 9 to 18 are refrigerant pipes, which are the same as those of the conventional multi-room air conditioner shown in FIG. A non-azeotropic refrigerant mixture is used as the refrigerant in the refrigerant circuit.

Reference numeral 19 denotes a first dryness changing unit for changing the dryness of a refrigerant provided in the middle of the first indoor heat exchanger 3 which is a condenser, and reference numeral 20 denotes the first dryness change unit 19. A liquid mixing pipe for injecting the liquid refrigerant from the refrigerant pipe 14 into the second, a second dryness changing unit 21 for changing the dryness of the refrigerant provided in the middle of the second indoor heat exchanger 4 as an evaporator, Reference numerals 22 and 23 denote high-pressure and low-pressure gas mixing tubes for injecting the gas refrigerant from the refrigerant pipe 11 into the second dryness changing unit 21, and reference numeral 24 denotes a mixed gas decompression means for decompressing the injected gas refrigerant. The dryness changing units 19 and 21, the liquid mixing pipe 20, the gas mixing pipes 22 and 23, and the mixed gas decompression means 24 constitute dryness changing means.

FIG. 2 is a partial side sectional view showing an example of the first dryness changing unit 19 in the first embodiment, and FIG.
FIG. 4 is a phase equilibrium diagram showing a change in the composition of the refrigerant by the dryness changing section 19, FIG. 4 is a partial side sectional view showing an example of the second dryness changing section 21, and FIG. FIG. 4 is a phase equilibrium diagram showing a change in composition of. In the figure, reference numeral 19 denotes a heat transfer tube of the first indoor heat exchanger 3 which constitutes a first dryness changing unit;
a is a nozzle-shaped opening at the tip of the liquid mixing tube 20, 21 is a heat transfer tube of the second indoor heat exchanger 4 constituting a second dryness changing unit,
Reference numeral 23a denotes a nozzle-shaped opening at the tip of the low-pressure gas mixing pipe 23.

Next, the flow of the refrigerant according to the first embodiment will be described. The high-temperature and high-pressure refrigerant discharged from the compressor 1 flows into the outdoor heat exchanger 2 through the discharged refrigerant pipe 9, where it exchanges heat with outdoor air to be cooled, condensed to a certain degree of dryness, and is in a gas-liquid two-phase state. And flows into the gas-liquid separator 5 through the refrigerant pipe 10. In the gas-liquid separator 5, the refrigerant is divided into a liquid refrigerant and a gas refrigerant, and the gas refrigerant is reduced in dryness by the first dryness changing unit 19 in the first indoor heat exchanger 3, The refrigerant is converted into a gas-liquid two-phase refrigerant having a high degree, is condensed until supercooling is obtained, and is decompressed by the first decompression means 6 to become a liquid refrigerant. The liquid refrigerant separated by the gas-liquid separator 5 flows through the bypass refrigerant pipe 14 to the third pressure reducing means 8.
, And merges with the liquid refrigerant from the first indoor heat exchanger 3 and the first decompression means 6. The combined liquid refrigerant flows into the second pressure reducing means 7 through the refrigerant pipe 16,
Here, the pressure is reduced to a low pressure and evaporated in the second indoor heat exchanger 4, and the dryness is increased by the second dryness changing unit 21. Return to

Next, the operation of the first dryness changing unit 19 will be described with reference to FIG.
And FIG. The refrigerant flowing from the high-pressure gas refrigerant pipe 11 to the first dryness changing section 19 which is the heat transfer pipe of the first indoor heat exchanger 3 is supplied from the refrigerant pipe 14 to the liquid mixing pipe 20.
And is mixed with the liquid refrigerant ejected from the front end opening 20a of the refrigerant to form a gas-liquid two-phase refrigerant having a small dryness. In FIG. 3, if the composition of the refrigerant upstream of the liquid mixing tube tip opening 20a of the first dryness changing unit 19 is A and the composition of the downstream refrigerant is B, the saturated liquid temperature Tao in the upstream composition A On the other hand, in the composition B in the downstream part, the saturated liquid temperature becomes Tbo. That is, since Tao <Tbo, the condensing temperature of the composition B is higher than that of the composition A, and the condensing ability is larger. Therefore, by mixing the liquid refrigerant with the refrigerant being condensed, the condensing temperature rises, and the condensing ability can be improved. Further, by controlling the composition or the flow rate of the liquid refrigerant flowing from the liquid mixing pipe 20, the condensing capacity can be made variable.

Next, the operation of the second dryness changing unit 21 will be described with reference to FIG.
And FIG. The refrigerant flowing from the low-pressure two-phase refrigerant pipe 17 to the second dryness changing section 21 which is the heat transfer pipe of the second indoor heat exchanger 4 is supplied from the refrigerant pipe 11 to the high-pressure gas mixing pipe 22, the pressure reducing means 24 and the low-pressure gas mixing. Through tube 23,
It is mixed with the gas refrigerant jetted from the distal end opening 23a to become a gas-liquid two-phase refrigerant having a large dryness. In FIG.
If the composition of the refrigerant upstream of the gas mixing tube tip opening 23a of the second dryness changing section 21 is A and the composition of the downstream refrigerant is C, the saturation gas temperature is Tao in the upstream composition A. On the other hand, in the composition C in the downstream part, the saturation gas temperature is Tco.
That is, since Tao> Tco, the evaporation temperature in the case of the composition C is lower than that in the case of the composition A, and the evaporation ability is higher.
Therefore, by mixing the gaseous refrigerant with the refrigerant in the middle of evaporation, the evaporation temperature is reduced, and the evaporation ability can be improved. Further, by controlling the composition or the flow rate of the gas refrigerant flowing from the gas mixing pipe 23, it is possible to make the evaporation capacity variable.

Embodiment 2 FIG. 6 is a schematic configuration diagram showing a refrigerant circuit at the time of simultaneous cooling / heating operation mainly for cooling in Embodiment 2 of the present invention. In FIG. A first indoor heat exchanger operating as a condenser, 4 a second indoor heat exchanger operating as an evaporator
Indoor heat exchanger, 5 is a gas-liquid separator, 6 is a first decompression means, 7 is a second decompression means, 8 is a third decompression means, 9-1
Reference numeral 8 denotes a refrigerant pipe, which is the same as the multi-room air conditioner according to the first embodiment shown in FIG. Reference numeral 25 denotes a dryness changing unit provided in the gas-liquid separator 5 for changing the dryness of the refrigerant to the refrigerant pipe 11. A non-azeotropic refrigerant mixture is used as the refrigerant in the refrigerant circuit.

FIG. 7 is a partial sectional side view showing an example of the dryness changing means 25. Reference numeral 11a denotes a U-shaped pipe portion bent in a U-shape in the gas-liquid separator 5 of the refrigerant pipe 11, and 27 denotes this U-shaped portion. A hole 28 provided in the lower part of the pipe 11a is a liquid refrigerant. FIG. 8 shows a means 25 for changing the dryness of the refrigerant in the gas-liquid separator 5.
FIG. 4 is a phase equilibrium diagram showing a change in the composition of the refrigerant due to the following.

Next, the flow of the refrigerant according to the second embodiment will be described. The high-temperature and high-pressure refrigerant discharged from the compressor 1 flows into the outdoor heat exchanger 2 through the discharged refrigerant pipe 9, where it exchanges heat with outdoor air to be cooled, condensed to a certain degree of dryness, and is in a gas-liquid two-phase state. And flows into the gas-liquid separator 5 through the refrigerant pipe 10. In the gas-liquid separator 5, the dryness is reduced by the liquid refrigerant and the dryness changing means 25, that is, the gaseous refrigerant is sucked from the end of the U-shaped tube 11 a and the liquid refrigerant is sucked from the hole 27. The gas-liquid two-phase refrigerant flows through the refrigerant pipe 11, is condensed in the first indoor heat exchanger 3 until it is supercooled, and is decompressed by the first decompression means 6. And becomes a liquid refrigerant. The liquid refrigerant separated by the gas-liquid separator 5 is slightly depressurized by the third decompression means 8 via the bypass refrigerant pipe 14 and then transmitted from the first indoor heat exchanger 3 and the first decompression means 6. With the liquid refrigerant. The merged liquid refrigerant flows through the refrigerant pipe 16 into the second decompression means 7, where it is decompressed to a low pressure and evaporated in the second indoor heat exchanger 4, and then becomes a gas refrigerant and becomes a refrigerant pipe 18 To return to the compressor 1.

Next, the effect of increasing the condensing capacity of the first indoor heat exchanger 3 by the dryness changing means 25 will be described with reference to FIG. 8, A is the composition of the refrigerant flowing into the gas-liquid separator 5, B is the composition of the liquid refrigerant in the gas-liquid separator 5, C is the composition of the gas refrigerant, and D is the gas-liquid separation by the dryness changing means 25. The composition of the gas-liquid mixed refrigerant when the liquid refrigerant and the gas refrigerant in the vessel 5 are mixed at an appropriate ratio is shown.

Here, a comparison is made between when the gas refrigerant flows through the first indoor heat exchanger 3 and when the gas-liquid mixed refrigerant flows. When only the gas refrigerant flows through the first indoor heat exchanger 3, the saturated liquid temperature at the condenser outlet is Tco and the average condensing temperature is Tc. On the other hand, when the gas-liquid two-phase refrigerant flows through the first indoor heat exchanger 3, the saturated liquid temperature at the condenser outlet becomes Tdo
The average condensation temperature becomes Td. Tco <Tdo, so Tc <
Td. Therefore, the condensing temperature in the first indoor heat exchanger 3 is higher when the gas-liquid two-phase refrigerant is supplied thereto than when only the gas refrigerant is supplied, and the first indoor heat exchanger 3
, The temperature difference from the heat exchange medium is increased, and the heat exchange capacity is increased.

FIG. 9 is a partial side sectional view showing another example of the dryness changing means 25. In this example, the refrigerant pipe 11 has an end located at an upper part in the gas-liquid separator 5, and A hole 27 is provided in the lower part of the gas-liquid separator 5 which is taken out from the lower part. Even with such a configuration, the same operation and effect as those of the dryness changing unit 25 shown in FIG. 7 are obtained.

Embodiment 3 FIG. 10 is a schematic configuration diagram showing a refrigerant circuit at the time of simultaneous cooling / heating operation mainly for cooling according to Embodiment 3 of the present invention. In the figure, 1 is a compressor, 2 is an outdoor heat exchanger that operates as a condenser, A first indoor heat exchanger that operates as a condenser, 4 is a second indoor heat exchanger that operates as an evaporator, 5 is a gas-liquid separator, 6 is first decompression means, and 7 is second decompression means. , 8 are third decompression means, 9 to 1
Reference numeral 8 denotes a refrigerant pipe, which is the same as the multi-room air conditioner according to the first embodiment shown in FIG. 29 is a gas refrigerant pipe 1 connecting the gas-liquid separator 5 and the first indoor heat exchanger 3.
A gas-liquid mixing section provided in the middle of 1 and mixing the liquid refrigerant with the gas refrigerant in the gas refrigerant pipe 11 is a gas-liquid mixing pipe that sucks the liquid refrigerant from the liquid refrigerant pipe 14 into the gas-liquid mixing section 29. ,
The gas-liquid mixing section 29 and the gas-liquid mixing pipe 30 constitute a dryness changing unit. A non-azeotropic refrigerant mixture is used as the refrigerant in the refrigerant circuit.

FIG. 11 is a partial sectional side view showing the internal structure of the gas-liquid mixing section 29, wherein 11b is an inlet pipe, 11c is a nozzle section, 11d is a thin tube section, 11e is a mixing section, 11f is a diffuser section, and 11g is an outlet. Piping. FIG. 12 is a phase equilibrium diagram showing a change in the composition of the refrigerant in the gas-liquid mixing section 29, and FIG. 13 is a diagram showing the relationship between the dryness of the refrigerant at the inlet of the first indoor heat exchanger 3 and the efficiency of the refrigeration cycle.

Next, the flow of the refrigerant according to the third embodiment will be described. The high-temperature and high-pressure refrigerant discharged from the compressor 1 flows into the outdoor heat exchanger 2 through the discharged refrigerant pipe 9, where it exchanges heat with outdoor air to be cooled, condensed to a certain degree of dryness, and is in a gas-liquid two-phase state. And flows into the gas-liquid separator 5 through the refrigerant pipe 10. In the gas-liquid separator 5, the refrigerant is divided into a liquid refrigerant and a gas refrigerant, and this gas refrigerant flows into the gas-liquid mixing section 29 from the gas refrigerant pipe 11, and is sucked up from the liquid refrigerant pipe 14 through the gas-liquid mixing pipe 30. The liquid refrigerant is mixed with the liquid refrigerant, and is converted into a gas-liquid two-phase refrigerant having a certain degree of dryness, flows into the first indoor heat exchanger 3, where it is condensed until it is supercooled, and the first pressure reducing means 6 The pressure is reduced to a liquid refrigerant. The liquid refrigerant separated by the gas-liquid separator 5 is slightly depressurized by the third decompression means 8 via the bypass refrigerant pipe 14 and then transmitted from the first indoor heat exchanger 3 and the first decompression means 6. With the liquid refrigerant. The merged liquid refrigerant flows through the refrigerant pipe 16 into the second decompression means 7, where it is decompressed to a low pressure and evaporated in the second indoor heat exchanger 4, and then becomes a gas refrigerant and becomes a refrigerant pipe 18
To return to the compressor 1.

Next, the operation of the gas-liquid mixing section 29 will be described with reference to FIGS.
2 and FIG. The gas refrigerant from the gas-liquid separator 5 to the high-pressure gas refrigerant pipe 11 flows into the gas-liquid mixing section 29 from the inlet pipe 11b, and the narrow pipe section 11d flows through the nozzle section 11c.
The nozzle is accelerated and jetted to the mixing section 11e to reduce the static pressure at the nozzle outlet. With a decrease in the static pressure, the liquid refrigerant is sucked up from the liquid refrigerant pipe 14 through the gas-liquid mixing pipe 30, and the gas-liquid refrigerant is accelerated to the same speed in the mixing unit 11e, and then decelerated by the diffuser unit 11f and decelerated. The pressure is restored, and the refrigerant is converted into a gas-liquid two-phase refrigerant having an appropriate degree of dryness and flows out to the outlet pipe 11g.

Here, the thin tube portion 11 at the tip of the nozzle portion 11c
The static pressure P _{so at the} outlet d can be expressed by the following equation (1) from Bernoulli's theorem. P _so = P _si −1 / 2 · (ρ _i u _i2 −ρ _o u _o2 ) (1) where P _si is the static pressure at the inlet of the gas-liquid mixing section 29 and ρ _i is the inlet pressure at the inlet of the gas-liquid mixing section 29. Density, ρ _o is the density at the outlet of the thin tube portion 11d, u _i is the velocity at the inlet of the gas-liquid mixing unit 29, and u _o is the thin tube portion 11d.
d is the speed at the exit. The nozzle 11c is designed so that the following equation (2) is satisfied. P _so ≦ P _L + ρ _L gZ _L −ΔP (2) where g is the gravitational acceleration, Z _L is the vertical distance from the inlet of the gas-liquid mixing pipe 30 to the gas-liquid mixing section 29, and P _L is the gas-liquid mixing. The static pressure and ΔP of the refrigerant at the inlet of the pipe 30 are the frictional resistance until the liquid refrigerant flows through the gas-liquid mixing pipe 30 and flows into the mixing section 11e, and the liquid refrigerant flowing into the mixing section 11e is the nozzle section 11c.
Pressure loss including acceleration loss when accelerating to the speed of gas flowing out of the chamber, and varies depending on the shape of the mixing section.

As is clear from the above equation (1), the flow rate of the liquid refrigerant in the gas-liquid mixing section 29 changes in accordance with the gas refrigerant velocity at the tip of the nozzle 11c. And the inflow of the liquid refrigerant increases. As a result, regardless of the flow rate of the refrigerant flowing through the refrigerant pipe 11, the gas-liquid mixing ratio (dryness) τ _r of the refrigerant can be made substantially constant as shown in FIG. Here, the speed of the gas refrigerant flowing through the refrigerant pipe 11 changes according to the load and capacity of the first indoor heat exchanger 3 that performs heating. Furthermore, when the inflow of the liquid refrigerant is increased, the dryness of the refrigerant at the outlet of the gas-liquid mixing unit 29 is reduced, and the flow rate of the refrigerant in the first indoor heat exchanger 3 is increased. Since the pressure loss in the heat exchanger 3 increases and the condensing temperature decreases, the performance of the indoor unit for heating decreases.
Therefore, as shown in FIG. 13, the first indoor heat exchanger 3
There is an optimum value for the dryness of the refrigerant at the inlet, which maximizes the efficiency of the refrigeration cycle. Therefore, by adjusting the dryness of the refrigerant supplied to the first indoor heat exchanger 3 to this optimum value, it is possible to improve the efficiency of the refrigeration cycle in a wide range regardless of the load or capacity thereof. .

Embodiment 4 FIG. FIG. 14 is a refrigerant circuit diagram of a multi-room air conditioner according to Embodiment 4 of the present invention.
FIG. 16 is a refrigerant circuit diagram showing a refrigerant flow during simultaneous cooling / heating operation mainly for cooling (hereinafter referred to as cooling main operation), and FIG. 16 is a refrigerant flow during simultaneous cooling / heating operation mainly for heating (hereinafter referred to as heating main operation). FIG. 17 is a refrigerant circuit diagram showing the flow of refrigerant during an operation of performing only cooling in an indoor unit (hereinafter referred to as cooling only operation), and FIG. 18 is an operation of performing only heating in an indoor unit (hereinafter referred to as heating only). FIG. 4 is a refrigerant circuit diagram illustrating a flow of a refrigerant during operation).

In the figure, 1 is a variable displacement compressor, 2 is an outdoor heat exchanger, 5 is a gas-liquid separator, 11a, 11b, 11
c is a high-pressure gas refrigerant pipe, 29a, 29b, 29c is a gas-liquid mixing section, 30 is a gas-liquid mixing pipe, 31 is an outdoor unit, 32 is a branch controller, 33a, 33b, 33c is an indoor unit, 34
Is an accumulator, 35 is a four-way valve, 36a, 36b, 3
6c and 36d are check valves, and 37 and 38 are low-pressure and high-pressure refrigerant pipes connecting the outdoor unit 31 and the branch controller 32.
9 is a high-pressure gas refrigerant pipe, 40 is a high-pressure liquid refrigerant pipe, 41 is a medium-pressure refrigerant pipe, 42 is a second flow rate control means, 43 is a non-azeotropic refrigerant mixture, and is opened and closed only during the cold main operation. Valves, 44a, 44b, 44c are first switching on-off valves,
45a, 45b, 45c are second switching valves, 46 is third flow control means, 47 is a low-pressure refrigerant pipe, 48a,
8b, 48c are indoor heat exchangers, 49a, 49b, 49c
Is a first flow control means, 50a, 50b, and 50c are gas refrigerant pipes connecting the indoor units 33a, 33b, and 33c to the flow dividing controller 32, and 51a, 51b, and 51c are divided into the indoor units 33a, 33b, and 33c. Controller 32
And a medium-pressure refrigerant pipe that connects

Next, the flow of the refrigerant during the cooling main operation in the fourth embodiment will be described with reference to FIG. Now
The indoor unit 33a performs the heating operation, the indoor units 33b and 33c perform the cooling operation, the on-off valve 43 is opened, the first switching on-off valve 44a is closed, the 44b and 44c are open, and the second switching on-off valve 45a is Open, 45b, 45c are closed, and the third flow control means 46 is closed.

The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 of the outdoor unit 31 passes through the four-way valve 35 and passes through the outdoor heat exchanger 2.
, Where it is cooled by exchanging heat with the outdoor air, condensed to a certain degree of dryness, and becomes a gas-liquid two-phase state.
b, flows into the gas-liquid separator 5 in the branch controller 32 through the high-pressure refrigerant pipe 38. Here, the refrigerant is divided into a liquid refrigerant and a gas refrigerant, and this gas refrigerant is a high-pressure gas refrigerant pipe 39.
From the high-pressure liquid refrigerant pipe 40 to the on-off valve 43 and the liquid refrigerant sucked up through the gas-liquid mixing pipe 30 in the gas-liquid mixing section 29a. The refrigerant is turned into a refrigerant, passes through the second switching valve 45a and the gas refrigerant pipe 50a, and passes through the indoor heat exchanger 48a of the indoor unit 33a.
, Where heat is exchanged with room air to be heated and condensed, reduced in pressure by the first flow control means 49a to become a liquid refrigerant, and flows into the diversion controller 32 through the medium-pressure refrigerant pipe 51a. .

In the branching controller 32, the liquid refrigerant separated by the gas-liquid separator 5 is slightly depressurized by the second flow rate control means 42 through the high-pressure liquid refrigerant pipe 40, and then the indoor refrigerant is supplied by the medium-pressure refrigerant pipe 41. Liquid refrigerant flowing from the compressor 33a through the medium-pressure refrigerant pipe 51a into the medium-pressure refrigerant pipes 51b, 51b.
c, the first flow control means 4 of the indoor units 33b and 33c.
9b, 49c, where it is decompressed to a low pressure and exchanged with indoor air in the indoor heat exchangers 48b, 48c to be cooled and evaporated to become a gas refrigerant and to become a gas refrigerant pipe 50
b, 50c, the first switching on / off valves 44b, 44c of the diversion controller 32, the low-pressure refrigerant pipe 37, the check valve 36a of the outdoor unit 31, the four-way valve 35, and the accumulator 34, and return to the compressor 1.

Next, the flow of the refrigerant during the warm-up main operation will be described with reference to FIG. Now, it is assumed that the indoor units 33a and 33b perform the heating operation and the indoor unit 33c performs the cooling operation, the on-off valve 43 is closed, the first switching on-off valves 44a and 44b are closed,
44c is opened, the second switching valves 45a and 45b are opened,
45c is closed, the second flow control means 42 is closed, and the third flow control means 46 is opened.

The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 of the outdoor unit 31 passes through the four-way valve 35 to the check valve 36d.
The high-pressure refrigerant pipe 38 flows into the gas-liquid separator 5 in the diversion controller 32. The gas refrigerant from the gas-liquid separator 5 flows from the high-pressure gas refrigerant pipe 39 to the refrigerant pipes 11a and 11b, and is not mixed with the liquid refrigerant because the on-off valve 43 is closed in the gas-liquid mixing sections 29a and 29b. Switching valve 4
5a, 45b and gas refrigerant pipes 50a, 50b, flow into the indoor heat exchangers 48a, 48b of the indoor units 33a, 33b, where they are exchanged with indoor air for heating and condensed, and The pressure is reduced by the flow control means 49a, 49b to become a liquid refrigerant, and flows into the branch controller 32 through the medium-pressure refrigerant pipes 51a, 51b.

In the branch controller 32, the indoor unit 3
The liquid refrigerant that has flowed through the medium-pressure refrigerant pipes 51a and 51b from the 3a and 33b merges in the medium-pressure refrigerant pipe 41, and a part of the liquid refrigerant flows through the medium-pressure refrigerant pipe 51c and the first flow control means of the indoor unit 33c. 49c, where the pressure is reduced to a low pressure, and the indoor heat exchanger 48c exchanges heat with indoor air to cool and evaporate. The remaining liquid refrigerant in the medium pressure refrigerant pipe 41 is the third liquid refrigerant.
The refrigerant is reduced in pressure by the flow control means 46, becomes a gas-liquid two-phase refrigerant, flows into the low-pressure refrigerant pipe 47, evaporates in the indoor heat exchanger 48c, and merges with the gas refrigerant flowing through the gas refrigerant pipe 50c and the first switching valve 44c. And flows into the outdoor heat exchanger 2 through the low-pressure refrigerant pipe 37 and the check valve 36c of the outdoor unit 31, where it exchanges heat with outdoor air and evaporates to become a gaseous refrigerant, and passes through the four-way valve 35 and the accumulator 34. Return to the compressor 1.

Next, referring to FIG. 17, all the indoor units 33a, 3
The flow of the refrigerant at the time of the cooling only operation in which the cooling operation of the cooling units 3b and 33c is performed will be described. At this time, the on-off valve 43 is closed,
The switching valves 44a, 44b, 44c are opened, all the second switching valves 45a, 45b, 45c are closed, and the third flow control means 46 is closed.

The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 of the outdoor unit 31 passes through the four-way valve 35 and passes through the outdoor heat exchanger 2.
, Where it is cooled and condensed into liquid refrigerant by heat exchange with outdoor air, and flows into the gas-liquid separator 5 in the flow dividing controller 32 through the check valve 36 b and the high-pressure refrigerant pipe 38.
The liquid refrigerant from the gas-liquid separator 5 is slightly depressurized by the second flow control means 42 through the high-pressure liquid refrigerant pipe 40, and then flows through the medium-pressure refrigerant pipe 41 and the medium-pressure refrigerant pipes 51a, 51b, 51c. Then, the air flows into the first flow control means 49a, 49b, 49c of the indoor units 33a, 33b, 33c, where the pressure is reduced to a low pressure, and the indoor heat exchangers 48a, 48b, 48c exchange heat with indoor air to perform cooling. And evaporates to become a gas refrigerant,
Gas refrigerant pipes 50a, 50b, 50c, first switching on-off valves 44a, 44b, 44c of the branch controller 32,
The refrigerant returns to the compressor 1 through the low-pressure refrigerant pipe 37, the check valve 36a of the outdoor unit 31, the four-way valve 35, and the accumulator 34.

Next, referring to FIG. 18, all the indoor units 33a, 3
A description will be given of the flow of the refrigerant during the heating only operation in which the heating operation is performed on the heating units 3b and 33c. At this time, the on-off valve 43 is closed,
The switching valves 44a, 44b, 44c are closed, all the second switching valves 45a, 45b, 45c are opened, and the second flow control means 42 is closed.

Then, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 of the outdoor unit 31 passes through the four-way valve 35 to the check valve 36d,
The high-pressure refrigerant pipe 38 flows into the gas-liquid separator 5 in the diversion controller 32. The gas refrigerant from the gas-liquid separator 5 is supplied from the high-pressure gas refrigerant pipe 39 to the refrigerant pipes 11a, 11b,
11c, the gas-liquid mixing sections 29a, 29b, and 29c close the second switching on-off valves 45a, 45b, and 45c without being mixed with the liquid refrigerant because the on-off valve 43 is closed. To the indoor units 33a, 33b,
33c, flows into the indoor heat exchangers 48a, 48b, 48c, where it is heat-exchanged with room air, heated and condensed, and decompressed by the first flow control means 49a, 49b, 49c to become a liquid refrigerant. , Medium pressure refrigerant pipes 51a, 51
b, 51c, merges in the medium-pressure refrigerant pipe 41 of the branching controller 32, is decompressed by the third flow control means 46, becomes a gas-liquid two-phase refrigerant, flows into the low-pressure refrigerant pipe 47, and flows into the low-pressure refrigerant pipe 37, the outdoor unit. The refrigerant flows into the outdoor heat exchanger 2 via the check valve 36c of 31, and then exchanges heat with the outdoor air to evaporate into a gas refrigerant, and returns to the compressor 1 through the four-way valve 35 and the accumulator 34.

As described above, the gas-liquid mixing sections 29a, 29b, 29c, the gas-liquid mixing pipe 30, and the on-off valve 43 are provided in the refrigerant circuit of the conventional multi-chamber air conditioner, and the non-azeotropic mixed refrigerant is provided. By using the open / close valve 43 only during the cold main operation in use, the refrigeration cycle can be operated efficiently both when using a single refrigerant, an azeotropic mixed refrigerant, and when using a non-azeotropic mixed refrigerant. can do.

Embodiment 5 19 to 30 show a multi-room air conditioner according to Embodiment 5 of the present invention.
9 is a refrigerant circuit diagram thereof, FIG. 20 is a refrigerant circuit diagram showing the flow of the refrigerant in the cold main operation, FIG. 21 is a refrigerant circuit diagram showing the flow of the refrigerant in the warm main operation, and FIG. FIG. 23 is a refrigerant circuit diagram showing a refrigerant flow during a heating only operation, FIG. 24 is a block diagram showing a control system, and FIG. 25 is a flowchart showing an algorithm of refrigerant composition calculation. 26 is a flowchart showing a control algorithm of the compressor and the outdoor fan, FIG. 27 is a flowchart showing a control algorithm of the second flow control means, and FIG.
Is a flowchart showing a control algorithm of the third flow control means, FIG. 29 is a flowchart showing a control algorithm of the bypass flow control means, and FIG. 30 is a flowchart showing a control algorithm of the first flow control means.

In the drawing, 1 is a variable displacement compressor, 2 is an outdoor heat exchanger, 5 is a gas-liquid separator, 11a, 11b, 11
c is a high-pressure gas refrigerant pipe, 29a, 29b, 29c is a gas-liquid mixing section, 30 is a gas-liquid mixing pipe, 31 is an outdoor unit, 32 is a branch controller, 33a, 33b, 33c is an indoor unit, 34
Is an accumulator, 35 is a four-way valve, 36a, 36b, 3
6c and 36d are check valves, 37 and 38 are low-pressure and high-pressure refrigerant pipes, 39 is a high-pressure gas refrigerant pipe, 40 is a high-pressure liquid refrigerant pipe,
41 is a medium pressure refrigerant pipe, 42 is a second flow control means, 43
Is an on-off valve, 44a, 44b and 44c are first switching on-off valves, and 45a, 45b and 45c are second switching on-off valves.
6 is a third flow control means, 47 is a low-pressure refrigerant pipe, 48
a, 48b, 48c are indoor heat exchangers, 49a, 49b,
49c is a first flow control means, 50a, 50b, 50c
Is a gas refrigerant pipe connecting each indoor unit 33a, 33b, 33c and the branch controller 32, 51a, 51b, 51
c is a medium-pressure refrigerant pipe, and the above is the fourth embodiment shown in FIG.
Is similar to

52 is an outdoor fan for the outdoor heat exchanger, 53
Is a bypass pipe branching from the medium-pressure refrigerant pipe 41 downstream of the second flow rate control means 42 or the upstream high-pressure liquid refrigerant pipe 40 to the low-pressure refrigerant pipe in the branch flow controller 32, and 54 is this bypass pipe. A bypass flow rate control means provided upstream of 53, 55a, 55b, 55c is a first supercooling heat exchanger that exchanges heat with medium pressure refrigerant pipes 51a, 51b, 51c, and 56 is a heat exchange with high pressure liquid refrigerant pipe 40. A second subcooling heat exchanger.

57 is a first temperature detecting means for detecting the temperature of the refrigerant upstream of the bypass flow rate control means 54; 58 is a second temperature detecting means for detecting the temperature of the refrigerant downstream of the bypass flow rate control means 54; The first pressure detecting means for detecting the refrigerant pressure downstream of the control means 54,
Second pressure detecting means for detecting the discharge pressure of the compressor, 61 is third pressure detecting means for detecting the suction pressure of the compressor 1, and 62 is the refrigerant in the high-pressure liquid refrigerant pipe 40 upstream of the second flow control means 42. Third temperature detecting means for detecting the temperature, 63 is fourth temperature detecting means for detecting the refrigerant temperature downstream of the second subcooling heat exchanger 56 in the bypass pipe 53, and 64 is the bypass pipe 5
Third pressure detecting means 65 for detecting the refrigerant pressure at the branch point from the medium-pressure refrigerant pipe 41. Reference numeral 65 denotes the refrigerant pressure of the high-pressure gas refrigerant pipe 39 or the high-pressure liquid refrigerant pipe 40 which is the outlet of the gas-liquid separator 5. Pressure detecting means 66a, 66b for detecting
66c is connected to the indoor heat exchangers 48a, 48b, 48c and the first
Fifth temperature detecting means 67a, 67b, 6 for detecting the refrigerant temperature between the flow rate controlling means 49a, 49b, 49c.
Reference numeral 7c denotes sixth temperature detecting means for detecting the refrigerant temperature of the gas refrigerant pipes 50a, 50b, 50c connected to the indoor heat exchangers 48a, 48b, 48c.

Reference numeral 68 denotes a detected value T of the first temperature detecting means 57.
₁ , a refrigerant composition calculator 69 for calculating the composition of the refrigerant from the detected value T _{2 of} the second temperature detector 58 and the detected value P _{1 of} the first pressure detector 59,
Of the refrigerant composition value α, which is the calculation result of
Detection value P ₂ 0, and according to the detected value P ₃ of the third pressure detecting means 61, first a compressor, an outdoor fan control device for controlling the rotational speed of the operating frequency and the outdoor fan of the compressor 1 , The refrigerant composition value α from the refrigerant composition calculation device 68, the detection value T ₂ of the _second temperature detection means 58, the third
The detected value T ₃ of the temperature detecting means 62 _, the fourth temperature detecting means 6
Third detection value T _4, the detection value P ₄ of the fourth pressure detecting means 64,
And a detection value P5 of the _fifth pressure detecting means 65, and a second controller which outputs control signals of the second flow rate controlling means 42, the third flow rate controlling means 46, and the bypass flow rate controlling means 54. , 71a to 71c are the indoor units 33a, 33b,
33c, the saturated liquid temperature value TC calculated by the second controller 70, the fifth temperature detecting means 66a, 66b, 6
Detection value T ₅ of 6c, sixth temperature detection means 67a, 67
b, the first flow control means 4 according to the detected value T _{6 of} 67c.
This is a third controller that outputs control signals 9a, 49b, and 49c.

Next, the flow of the refrigerant during the cold main operation in the fifth embodiment will be described with reference to FIG. Now
The indoor unit 33a performs the heating operation, the indoor units 33b and 33c perform the cooling operation, the on-off valve 43 is opened, the first switching on-off valve 44a is closed, the 44b and 44c are open, and the second switching on-off valve 45a is Open, 45b, 45c are closed, and the third flow control means 46 is closed.

Then, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 of the outdoor unit 31 flows through the four-way valve 35 to the outdoor heat exchanger 2.
, Where it is cooled by exchanging heat with the outdoor air, condensed to a certain degree of dryness, and becomes a gas-liquid two-phase state.
b, flows into the gas-liquid separator 5 in the branch controller 32 through the high-pressure refrigerant pipe 38. Here, the refrigerant is divided into a liquid refrigerant and a gas refrigerant, and this gas refrigerant is a high-pressure gas refrigerant pipe 39.
From the high-pressure liquid refrigerant pipe 40 to the on-off valve 43 and the liquid refrigerant sucked up through the gas-liquid mixing pipe 30 in the gas-liquid mixing section 29a. The refrigerant is turned into a refrigerant, passes through the second switching valve 45a and the gas refrigerant pipe 50a, and passes through the indoor heat exchanger 48a of the indoor unit 33a.
, Where heat is exchanged with room air to be heated and condensed, reduced in pressure by the first flow control means 49a to become a liquid refrigerant, and flows into the diversion controller 32 through the medium-pressure refrigerant pipe 51a. .

In the branching controller 32, the liquid refrigerant separated by the gas-liquid separator 5 is slightly depressurized by the second flow rate control means 42 through the high-pressure liquid refrigerant pipe 40, and then the indoor refrigerant is changed by the medium-pressure refrigerant pipe 41. Joins with the liquid refrigerant that has flowed from the device 33a through the medium-pressure refrigerant pipe 51a. Further, a part of the liquid refrigerant decompressed by the second flow control means 42 is diverted to the bypass pipe 53, decompressed by the bypass flow control means 54, and is cooled by the first subcooling heat exchangers 55a, 55b, 55c. The liquid refrigerant flowing through the medium-pressure refrigerant pipes 51a, 51b, and 51c is supercooled by the second subcooling heat exchanger 56, and the liquid refrigerant flowing through the high-pressure liquid refrigerant pipe 40 is evaporated and the low-pressure refrigerant pipe itself evaporates. 37.

The first subcooling heat exchangers 55a, 55b, 5
The remaining liquid refrigerant supercooled by 5c and the second subcooling heat exchanger 56 flows into the first flow control means 49b, 49c of the indoor units 33b, 33c via the medium-pressure refrigerant pipes 51b, 51c. Here, the pressure is reduced to a low pressure, and the indoor heat exchanger 48b is
At 48c, heat is exchanged with the room air to perform cooling and evaporate to become a gas refrigerant, the gas refrigerant pipes 50b and 50c, and the first switching valves 44b and 44 of the branch controller 32.
Then, the refrigerant flows into the low pressure refrigerant pipe 37, the check valve 36 a of the outdoor unit 31, the four-way valve 35, and the accumulator 34, and returns to the compressor 1.

As described above, in this embodiment, the liquid refrigerant from the gas-liquid separator 5 which becomes a refrigerant rich in high boiling point components during the cooling main operation is partially flown into the bypass pipe 53, so that the high-pressure liquid refrigerant pipe 40 and medium pressure refrigerant pipes 51a, 51b, 5
Heat is recovered by exchanging heat with the liquid refrigerant in 1c, and the refrigerant rich in the high boiling point component is bypassed in the bypass pipe 53, and the composition of the refrigerant flowing through the indoor units 48b and 48c to be cooled becomes low boiling point component. The refrigerant becomes rich, the evaporation temperature is lower than that of the refrigerant having the same composition as the refrigerant discharged from the compressor 1, the capacity of the cooling indoor unit is increased, and the refrigeration cycle can be operated efficiently.

Next, the flow of the refrigerant during the warm-up main operation will be described with reference to FIG. Now, it is assumed that the indoor units 33a and 33b perform the heating operation and the indoor unit 33c performs the cooling operation, the on-off valve 43 is closed, the first switching on-off valves 44a and 44b are closed,
44c is opened, the second switching valves 45a and 45b are opened,
45c is closed, the second flow control means 42 is closed, and the third flow control means 46 is opened.

Then, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 of the outdoor unit 31 passes through the four-way valve 35 to the check valve 36d.
The high-pressure refrigerant pipe 38 flows into the gas-liquid separator 5 in the diversion controller 32. The gas refrigerant from the gas-liquid separator 5 flows from the high-pressure gas refrigerant pipe 39 to the refrigerant pipes 11a and 11b, and is not mixed with the liquid refrigerant because the on-off valve 43 is closed in the gas-liquid mixing sections 29a and 29b. Switching valve 4
5a, 45b and gas refrigerant pipes 50a, 50b, flow into the indoor heat exchangers 48a, 48b of the indoor units 33a, 33b, where they are exchanged with indoor air for heating and condensed, and The pressure is reduced by the flow control means 49a, 49b to become a liquid refrigerant, and flows into the branch controller 32 through the medium-pressure refrigerant pipes 51a, 51b.

In the branch controller 32, the indoor unit 3
The liquid refrigerant that has flowed through the medium-pressure refrigerant pipes 51a and 51b from the 3a and 33b merges in the medium-pressure refrigerant pipe 41, and a part of the liquid refrigerant flows through the medium-pressure refrigerant pipe 51c and the first flow control means of the indoor unit 33c. 49c, where the pressure is reduced to a low pressure, and the indoor heat exchanger 48c exchanges heat with indoor air to cool and evaporate. The remaining liquid refrigerant in the medium pressure refrigerant pipe 41 flows into the third flow control means 46 and
Divide into three. The refrigerant flowing into the third flow control means 46 is decompressed and becomes a gas-liquid two-phase refrigerant and flows into the low-pressure refrigerant pipe 47. Of the medium-pressure refrigerant pipe 51a by the supercooling heat exchangers 55a, 55b, 55c of
The refrigerant exchanges heat with the liquid refrigerant flowing through the refrigerants 51b and 51c to supercool these refrigerants.

The gas refrigerant evaporated in the indoor heat exchanger 48c and passed through the gas refrigerant pipe 50c and the first switching valve 44c;
Low-pressure refrigerant pipe 47 depressurized by the third flow control means 46
And the gas refrigerant from the bypass pipe 53 merge into the low-pressure refrigerant pipe 37 and flow into the outdoor unit 31.
Flows into the outdoor heat exchanger 2 through the non-return valve 36c, where it exchanges heat with the outdoor air and evaporates to become a gas refrigerant.
5. Return to the compressor 1 via the accumulator 34.

Next, referring to FIG. 22, all the indoor units 33a, 3
The flow of the refrigerant at the time of the cooling only operation in which the cooling operation of the cooling units 3b and 33c is performed will be described. At this time, the on-off valve 43 is closed,
The switching valves 44a, 44b, 44c are opened, all the second switching valves 45a, 45b, 45c are closed, and the third flow control means 46 is closed.

The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 of the outdoor unit 31 passes through the four-way valve 35 and passes through the outdoor heat exchanger 2.
, Where it is cooled and condensed into liquid refrigerant by heat exchange with outdoor air, and flows into the gas-liquid separator 5 in the flow dividing controller 32 through the check valve 36 b and the high-pressure refrigerant pipe 38.
The liquid refrigerant from the gas-liquid separator 5 is slightly depressurized by the second flow rate control means 42 through the high-pressure liquid refrigerant pipe 40, and then partially diverted from the medium-pressure refrigerant pipe 41 to the bypass pipe 53, The pressure is reduced by the bypass flow rate control means 54, and the medium-pressure refrigerant pipes 51 a,
The liquid refrigerant flowing through the high-pressure liquid refrigerant pipe 40 is supercooled by the second subcooling heat exchanger 56, and the liquid refrigerant itself evaporates and flows into the low-pressure refrigerant pipe 37.

The remaining refrigerant in the medium-pressure refrigerant pipe 41 passes through the medium-pressure refrigerant pipes 51a, 51b, and 51c to the indoor units 33a,
3b, 33c first flow control means 49a, 49b, 4
9c, where the pressure is reduced to a low pressure and the indoor heat exchanger 4
8a, 48b, and 48c, heat exchange with room air is performed, cooling is performed, and the refrigerant is evaporated to a gas refrigerant.
a, 50b, 50c, and the first switching on / off valves 44a, 44b, 44c of the diversion controller 32 to join the gas refrigerant from the bypass line 53, the low-pressure refrigerant pipe 37, and the check valve 36a of the outdoor unit 31. , The four-way valve 35 and the accumulator 34 to return to the compressor 1.

Next, referring to FIG. 23, all the indoor units 33a, 3
A description will be given of the flow of the refrigerant during the heating only operation in which the heating operation is performed on the heating units 3b and 33c. At this time, the on-off valve 43 is closed,
The switching valves 44a, 44b, 44c are closed, all the second switching valves 45a, 45b, 45c are opened, and the second flow control means 42 is closed.

Then, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 of the outdoor unit 31 passes through the four-way valve 35 to the check valve 36d.
The high-pressure refrigerant pipe 38 flows into the gas-liquid separator 5 in the diversion controller 32. The gas refrigerant from the gas-liquid separator 5 is supplied from the high-pressure gas refrigerant pipe 39 to the refrigerant pipes 11a, 11b,
11c, the gas-liquid mixing sections 29a, 29b, and 29c close the second switching on-off valves 45a, 45b, and 45c without being mixed with the liquid refrigerant because the on-off valve 43 is closed. To the indoor units 33a, 33b,
33c, flows into the indoor heat exchangers 48a, 48b, 48c, where it is heat-exchanged with room air, heated and condensed, and decompressed by the first flow control means 49a, 49b, 49c to become a liquid refrigerant. , Medium pressure refrigerant pipes 51a, 51
b and 51c flow into the diversion controller 32.

In the branching controller 32, the liquid refrigerant in the medium-pressure refrigerant pipes 51a, 51b, 51c is
1 and a part thereof is diverted to the bypass pipe 53, the pressure is reduced by the bypass flow rate control means 54, and the intermediate-pressure refrigerant pipes 51a, 51b,
The liquid refrigerant flowing through 1b and 51c is supercooled and evaporated, and flows into the low-pressure refrigerant pipe 37. The remaining liquid refrigerant that has joined in the medium-pressure refrigerant pipe 41 is decompressed by the third flow control means 46 and becomes a gas-liquid two-phase refrigerant.
3 and flows into the low-pressure refrigerant pipe 37,
The gas flows into the outdoor heat exchanger 2 through the check valve 36c of the outdoor unit 31, and exchanges heat with the outdoor air to evaporate into a gas refrigerant.

Next, the calculation of the composition of the refrigerant flowing through the refrigerant circuit in the refrigerant composition calculation device 68 will be described with reference to FIGS. 24 and 25. First, in step S1, the refrigerant temperature detection value T ₁ upstream of the bypass flow rate control means 54 detected by the first temperature detection means 57 is detected by the second temperature detection means 58 and the first pressure detection means 59. The detected refrigerant temperature value T ₂ and the detected pressure value P ₁ downstream of the bypass flow rate control means 54 are detected (hereinafter, detected),
In step S2, the composition value α of the refrigerant is assumed, and
3, the assumed refrigerant composition value α and the first refrigerant temperature detection value T
The enthalpy _HL of the liquid refrigerant upstream of the bypass flow rate control means 54 is calculated from _{1 using a} predetermined calculation formula, and step S4
From the refrigerant composition value α, the first refrigerant pressure detection value P ₁ , and the second refrigerant temperature detection value T _2.
4 enthalpy H _T downstream of the two-phase refrigerant is calculated, and the enthalpy calculated value H _T of liquid refrigerant enthalpy calculated value H _L and two-phase refrigerant are compared at step S5, if they do not match the flow returns to step S2. These steps S2~S5 are repeated while changing the assumption refrigerant composition value alpha, the calculation Once matches H _L and H _T ends, the refrigerant composition value alpha at that time is output from the refrigerant composition calculating unit 68 as a result of calculation .

Next, the control of the compressor 1 and the outdoor fan 52 in the first controller 69 will be described with reference to FIGS. 24 and 26. First, in step S6, the refrigerant composition value α, which is the calculation result of the refrigerant composition calculation device 68, is detected, and in step S7, the high pressure target value P _d ^* and the low pressure pressure in the refrigeration cycle corresponding to the refrigerant composition value α. target value P _s ^* is set. In step S8, the discharge pressure detection value P ₂ of the compressor 1 detected by the second pressure detection means 60 and the suction pressure detection value P _{3 of} the compressor 1 detected by the third pressure detection means 61 are detected. , In step S9,
The difference ΔP _d between the discharge pressure detection value P ₂ and the high pressure target value P _d ^* ,
And the difference Δ between the suction pressure detection value P ₃ and the low pressure target value P _s ^*
P _s is calculated, and these calculated values ΔP _d , Δ
The operating frequency change width ΔF _{comp of} the compressor 1 and the rotation speed change width ΔAK of the outdoor fan 52 are calculated in accordance with P _s, and the operating frequency of the compressor 1 and the rotation of the outdoor fan 52 are calculated in step S11 in accordance with these calculated values. The number changes. And
In step S12, the elapsed time from the start of the compressor 1 or the previous change, Time, detected by a timer (not shown), is compared with a predetermined time Time ^*, and the predetermined time Time ^* is detected ^. Until the time elapses, step S8
Step S12 is repeated, and after elapse of the predetermined time Time ^* , the timer is reset in Step S13 and Step S6
Return to In this embodiment, the operating frequency of the compressor 1 and the number of revolutions of the outdoor fan 52 are controlled, but other means may be used as long as the capacity of the compressor 1 and the outdoor heat exchanger 2 is controlled. Good.

Next, the control of the second flow control means 42 in the second controller 70 will be described with reference to FIGS. 24 and 27. First, in step S14, the operation mode of the air conditioner is detected. The process proceeds to step S15 during the cooling main operation, proceeds to step S16 during the cooling only operation, and proceeds to step S17 during the heating only operation and the warm main operation.

In the cold main operation, the operation is recognized as the cold main operation in step S15, and the process proceeds to step S18, in which the refrigerant composition value α calculated by the refrigerant composition calculating device 68 and the high-pressure refrigerant detected by the fifth pressure detecting means 65 are used. Pressure value P ₅ and third
High-pressure refrigerant temperature value T detected by the temperature detecting means 62 of FIG.
₃ are detected, and the detected refrigerant composition value α, high-pressure refrigerant pressure value P ₅ , and high-pressure refrigerant temperature value T ₃ are detected in step S19.
The supercooling degree value SC of the refrigerant is calculated from
This subcooling degree value SC is compared with a preset target subcooling degree value SC ^*, and the subcooling degree value SC is compared with the target subcooling degree value S.
If it exceeds C ^* , the process proceeds to step S21, and the opening of the second flow rate control means 42 is increased. If the subcooling degree SC is equal to or less than the target supercooling degree SC ^* , the process proceeds to step S22.
Of the flow rate control means 42 is reduced. Step S2
Comparison of 3 is set in advance and the elapsed time Time in the predetermined time Time ^* is performed, the process returns to step S18 if the predetermined time Time ^* less, steps S18~ step S23 is repeated, step after a predetermined time Time ^* elapsed In S24, the timer is reset and the process proceeds to step S25, where a change in the operation mode is confirmed. If there is a change in the operation mode, the process returns to step S14, and if there is no change, the process returns to step S18.

In the cooling only operation, the cooling operation is recognized in step S16 and the process proceeds to step S26, in which the opening of the second flow control means 42 is fully opened, and in step S27, the elapsed time Time and the predetermined time set in advance are set. Comparison with Time ^* is performed, and if it is equal to or less than the predetermined time Time ^* , step S28
Then, the flow returns to step S27 without changing the opening degree of the second flow control means 42 while being fully opened, and after a predetermined time Time ^{* has} elapsed, the timer is reset in step S29 and step S3 is performed.
The process proceeds to step S0, where a change in the operation mode is confirmed. If there is a change in the operation mode, the process returns to step S14, and if there is no change, the process returns to step S27.

At the time of the heating only operation or the warming-up main operation, the operation is recognized as the heating only operation or the warming-up main operation at step S17, and the process proceeds to step S31. The time Time is compared with a predetermined time Time ^* which is set in advance, and the predetermined time Tim is compared.
If it is equal to or less than e ^* , the process proceeds to step S33, and the opening degree of the second flow rate control means 42 is not changed while being fully closed, and step S32 is performed.
After a lapse of the predetermined time Time ^* , the timer is reset in step S34, and the process proceeds to step S35. In step S35, a change in the operation mode is confirmed.
The process returns to step S14, and if there is no change, the process returns to step S32.

Next, the control of the third flow control means 46 in the second controller 70 will be described with reference to FIGS. 24 and 28. First, in step S36, the operation mode of the air conditioner is detected, and the process proceeds to step S37 during cooling only operation or cooling main operation, and proceeds to step S38 during cooling only operation or warm main operation.

At the time of the cooling only operation or the cooling main operation, the cooling operation is recognized as the cooling only operation or the cooling main operation in step S37, and the process proceeds to step S39. The time Time is compared with a predetermined time Time ^* which is set in advance, and the predetermined time Time ^* is compared ^.
If not, the process proceeds to step S41 and returns to step S40 without changing the opening degree of the third flow control means 46 to the fully closed state. After a predetermined time Time ^{* has} elapsed, the timer is reset in step S42 and the process proceeds to step S43. The change of the operation mode is confirmed, and if there is a change in the operation mode, step S3
6, and if there is no change, the process returns to step S40.

[0078] At or during warm main operating heating only operation, the process proceeds to step S44 is recognized as the total heating or warm main operation at step S38, the fourth and intermediate pressure refrigerant pressure value P ₄ detected by the pressure detecting means 64 of the high pressure refrigerant pressure value P ₅ detected by the pressure detecting means 65 of 5 is detected, the pressure difference between a preset target the high pressure refrigerant pressure value P ₅ and the intermediate-pressure refrigerant pressure value P ₄ detected by the step S45 A comparison with the value ΔP ₄₅ ^* is performed. If the pressure difference exceeds the target value, the process proceeds to step S46, where the opening of the third flow rate control means 46 is reduced, and the pressure difference (P ₅ −P ₄ ) is set to the target value. If it is equal to or less than the value ΔP ₄₅ ^* , the process proceeds to step S47, and the opening degree of the third flow control means 46 is increased. In step S48, the elapsed time Time is compared with a predetermined time Time ^* which is set in advance. If the time is less than or equal to the predetermined time Time ^* , the process returns to step S44 and returns to step S44.
Steps S44 to S48 are repeated, the timer is reset in step S49 after a lapse of a predetermined time Time ^{*, and the} process proceeds to step S50, where a change in the operation mode is confirmed. If there is a change in the operation mode, the process returns to step S36. If it is, the process returns to step S44.

Next, the control of the bypass flow rate control means 54 in the second controller 70 will be described with reference to FIGS. First, in step S51, the operation mode of the air conditioner is detected, and the process proceeds to step S52 during cooling only operation or cooling main operation, and proceeds to step S53 during cooling only operation or warm main operation.

During the cooling only operation or the cooling main operation, the cooling operation is recognized as the cooling only operation or the cooling main operation in step S52, and the process proceeds to step S54. The value T ₂ and the refrigerant temperature value T ₄ downstream of the second subcooling heat exchanger 56 detected by the fourth temperature detecting means 63 are detected. In step S55, the detected refrigerant temperature value T ₂ and refrigerant temperature are detected. the value T ₄ and difference superheat value SH of the refrigerant is calculated from, is compared with the degree of superheat value SH preset target degree of superheat value SH ^* in step S56, the superheat value SH is the target degree of superheat value SH ^*
If the superheat degree exceeds the target superheat value SH ^* , the operation proceeds to step S58, and the opening degree of the bypass flow control means 54 decreases. Is done. Comparison with a predetermined time Time ^* set in advance and the elapsed time Time in step S59 is performed, step S if a predetermined time Time ^* less
Returning to step S54, steps S54 to S59 are repeated, and after a lapse of a predetermined time Time ^* , the timer is reset in step S60, and the process proceeds to step S61.
Returning to step 1, if there is no change, return to step S54.

[0081] at the time or warm main operating heating only operation, the process proceeds to step S62 is recognized as the total heating or warm main operation at step S53, the fourth and intermediate pressure refrigerant pressure value P ₄ detected by the pressure detecting means 64 of the high pressure refrigerant pressure value P ₅ detected by the pressure detecting means 65 of 5 is detected, the pressure difference between a preset target the high pressure refrigerant pressure value P ₅ and the intermediate-pressure refrigerant pressure value P ₄ detected by the step S63 A comparison with the value ΔP ₄₅ ^* is performed, and if the pressure difference exceeds the target value, the process proceeds to step S64, where the opening of the bypass flow rate control means 54 is reduced, and the pressure difference (P ₅ −P ₄ ) is reduced to the target value ΔP If it is not more than ₄₅ ^* , the process proceeds to step S65, and the opening degree of the bypass flow rate control means 54 is increased. In step S66, the elapsed time Time is compared with a predetermined time Time ^* which is set in advance. If the time is equal to or shorter than the predetermined time Time ^* , the process returns to step S62, and steps S62 to S66 are repeated, and the predetermined time Time ^* is repeated ^.
After the elapse, the timer is reset in step S67, and the process proceeds to step S68. In step S68, a change in the operation mode is confirmed. If the operation mode is changed, the process returns to step S51. If not, the process returns to step S62.

Next, referring to FIG. 24 and FIG. 30, the third controller 7 provided in each of the indoor units 33a, 33b and 33c will be described.
First flow control means 54 by 1a, 71b, 71c
The control of a, 54b, and 54c will be described. First, in step S69, the operation mode of each indoor unit is detected,
The operation proceeds to step S70 during the cooling operation and to step S71 during the heating operation.

At the time of the cooling operation, the cooling operation is recognized in step S70 and the process proceeds to step S72, where the indoor heat exchangers 48a, 48b and 48c detected by the fifth temperature detecting means 66a, 66b and 66c and the first flow control are performed. Means 49
a, 49b, the refrigerant temperature value T ₅ between the 49c, sixth temperature detection means 67a, 67b, the gas refrigerant pipe 50a detected by 67c, 50b, the refrigerant temperature of 50c value T ₆
There are detected, these detected refrigerant temperature value T ₆ and the refrigerant temperature value T ₅ and superheat value SH of the refrigerant from the difference calculated in step S73, a predetermined target superheating this superheat value SH in step S74 The superheat degree SH is compared with the degree SH ^*.
If the value exceeds the target superheat value SH ^* , the process proceeds to step S75, and the opening of the first flow rate control means 49a, 49b, 49c is increased. If the superheat value SH is equal to or less than the target superheat value SH ^* , Proceeding to S76, the first flow rate control means 49
The opening degrees of a, 49b, and 49c are reduced. Step S7
Comparison with a predetermined time Time ^* set in advance and the elapsed time Time at 7 is carried out, the process returns to step S72 if the predetermined time Time ^* less, steps S72~ step S77 is repeated, step after a predetermined time Time ^* elapsed In S78, the timer is reset, and the process returns to step S69.

During the heating operation, the cooling operation is recognized in step S71, and the flow advances to step S79. Means 49
a, 49b, the refrigerant temperature value T ₅ between the 49c, the fifth pressure detecting means which is transmitted from the branch controller 32 65
Saturated liquid temperature value T of the high-pressure refrigerant pressure value P ₅ detected by
C is detected. Here, in the heating indoor unit during the cooling main operation, the sixth temperature detecting means 67a instead of the saturated liquid temperature value TC,
Gas refrigerant pipe 50a detected by 67b, 67c,
50b, it may be configured to detect a refrigerant temperature value T ₆ of 50c. Step S80 These sensed saturated liquid temperature value TC or a refrigerant temperature value T ₆ and the refrigerant temperature value T ₅ and from the difference of the refrigerant supercooling degree value SC is calculated by preset this degree of supercooling value SC in step S81 Is compared with the set target superheat degree value SC ^* . If the supercool degree value SC exceeds the target supercool degree value SC ^* , the process proceeds to step S82 and the first flow rate control means 4
The opening of 9a, 49b, 49c is increased, and the supercooling degree S
If C is equal to or less than the target supercooling degree value SC ^* , step S82
Then, the opening degree of the first flow control means 54a, 54b, 54c is reduced. In step S82, the elapsed time Time is compared with a predetermined time Time ^* which is set in advance. If the time is equal to or shorter than the predetermined time Time ^* , the process returns to step S79, and steps S79 to S84 are repeated to obtain the predetermined time Tim.
After e ^* , the timer is reset in step S85 and the process returns to step S69.

In this embodiment, since the control according to the composition of the refrigerant is performed as described above, abnormal noise of the refrigerant and liquid back to the compressor can be prevented, and the efficiency can be improved in all the operation modes. , And appropriate driving can be performed.

Embodiment 6 FIG. FIG. 31 is a flowchart illustrating a control algorithm of a compressor and an outdoor fan according to Embodiment 6 of the present invention, and FIG. 32 is a diagram illustrating a relationship between a capacity ratio of a heating indoor unit and a cooling indoor unit and a composition of a refrigerant flowing through the indoor unit. It is. 19 to 25 show the sixth embodiment.
Also applies.

Next, the control of the compressor 1 and the outdoor fan 52 in the first controller 69 will be described with reference to FIGS. 24, 31 and 32. First, in step S86, a refrigerant composition value α _cal which is a calculation result of the refrigerant composition calculation device 68 is detected. As shown in FIG. 32, the cold main operation, the composition of the refrigerant in equilibrium with the gas-liquid separator 5 in accordance with the ratio of the heating indoor functional force Q _e and cooling indoor function force Q _c are different. Therefore, a change in the refrigerant composition with respect to Q _c / Q _c is determined in advance, and the relationship between the cooling room functional force Q _c and the heating indoor functional force Q _e detected in step S87 is used in step S87.
At 88, the detected refrigerant composition value α _cal is corrected, and the composition α _c of the cooling indoor unit circulating refrigerant and the composition α _h of the heating indoor unit circulating refrigerant are obtained. ^* High pressure target value P _d ^* and the low-pressure pressure target value P _s in the refrigeration cycle in accordance with the refrigerant composition value alpha _c and alpha _h is set at step S89.

In step S90, the second pressure detecting means 6
0, the detected discharge pressure value P ₂ of the compressor 1 and the detected pressure value P _{3 of} the compressor 1 detected by the third pressure detecting means 61 are detected. ₂ and the high-pressure pressure target value P _d ^* the difference between [Delta] P _d, and the difference [Delta] P _s of the suction pressure detection value P ₃ and the low pressure target value P _s ^* is calculated, these calculated values [Delta] P _d at step 92, [Delta] P _s , The operating frequency change width ΔF _{comp of} the compressor 1 and the rotation speed change width ΔAK of the outdoor fan 52 are calculated, and step S9 is performed.
In 3, the operating frequency of the compressor 1 and the rotation speed of the outdoor fan 52 are changed according to these calculated values. Then, in step S94, the elapsed time Time and the preset predetermined time Time
^* Comparison with is performed until a predetermined time Time ^* elapses is repeated steps S90~ step S94, the timer is reset at a predetermined time Time ^* elapsed after step S95 returns to step S86.

As described above, in the sixth embodiment, the composition of the refrigerant circulating in the indoor unit is determined more accurately in the cold main operation, so that the refrigeration cycle in the cold main operation is more appropriately operated. be able to.

[0090]

As described above, according to the first aspect of the present invention, a non-azeotropic mixed refrigerant is used as the refrigerant, and the refrigerant returns to the compressor via the condenser, the pressure reducing means, and the evaporator. In the air conditioner provided with the refrigerant circuit, since the dryness changing means for changing the dryness of the refrigerant is provided in the middle of at least one of the condenser and the evaporator, the capacity of the evaporator or the condenser is improved. There is an effect that an air conditioner with improved or variable air quality can be obtained.

According to a second aspect of the present invention, a plurality of indoor heat exchangers and a gas-liquid separator are provided. The gas refrigerant separated by the gas-liquid separator is supplied to the heating indoor heat exchanger, and the liquid refrigerant is cooled. In a multi-room air conditioner that performs simultaneous cooling and heating with a refrigerant circuit that uses a non-azeotropic mixed refrigerant as a refrigerant, the liquid refrigerant is used as a gas refrigerant flowing into the heating indoor heat exchanger. Since the dryness changing means for injecting the refrigerant into the gas-liquid two-phase state refrigerant is provided, there is an effect that a multi-room air conditioner with improved performance of the heating indoor unit can be obtained.

According to the third aspect of the present invention, a non-azeotropic mixed refrigerant is used as a refrigerant, flows into the gas-liquid separator from the compressor via the outdoor heat exchanger, and is separated by the gas-liquid separator. The gas refrigerant passes through the first indoor heat exchanger and the first decompression unit, and joins with the liquid refrigerant separated by the gas-liquid separator and passed through the third decompression unit. In the multi-chamber air conditioner provided with a refrigerant circuit that returns to the compressor through the indoor heat exchanger, a liquid refrigerant is injected into the gas refrigerant flowing into the first indoor heat exchanger, and a gas-liquid two-phase Since the dryness changing means for providing the refrigerant in the state is provided, the capacity of the first indoor heat exchanger is increased, and there is an effect that a multi-room air conditioner capable of operating the refrigeration cycle efficiently can be obtained.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the liquid refrigerant inside the gas-liquid separator is provided in the pipe connecting the gas-liquid separator and the first indoor heat exchanger. Is provided, the gas-liquid two-phase refrigerant flowing to the first indoor heat exchanger can be easily created, the capacity of the first indoor heat exchanger increases, and the refrigeration cycle operates efficiently. There is an effect that a possible multi-room air conditioner can be obtained at low cost.

According to a fifth aspect of the present invention, in the third aspect of the invention, the gas-liquid separator and the first indoor heat exchanger are connected to each other in a gas refrigerant pipe. Since a gas-liquid mixing section for sucking up liquid refrigerant from a liquid refrigerant pipe connecting the pressure reducing means of No. 3 through a gas-liquid mixing pipe and mixing with the gas refrigerant in the gas refrigerant pipe is provided, the first indoor heat A multi-room air conditioner that can appropriately control the dryness of the gas-liquid two-phase state flowing through the exchanger and can improve the efficiency of the refrigeration cycle in a wide range regardless of the load and capacity of the indoor unit can be obtained. effective.

According to the sixth aspect of the present invention, an outdoor unit having a variable displacement compressor, a four-way valve, and an outdoor heat exchanger, and a plurality of indoor units each connected to the indoor heat exchanger and the first flow control means. The indoor unit, the outdoor unit and the high-pressure refrigerant pipe and the low-pressure refrigerant pipe are connected by two refrigerant pipes. Connected by medium-pressure refrigerant pipes,
A gas-liquid separator that separates the refrigerant from the high-pressure refrigerant pipe connected to the outdoor unit into gas and liquid and outputs the refrigerant to the high-pressure gas refrigerant pipe and the high-pressure liquid refrigerant pipe. The high-pressure liquid refrigerant pipe is connected to the indoor unit. Second flow control means connected between the plurality of medium-pressure refrigerant pipes, a low-pressure refrigerant pipe connected to the outdoor unit,
Third flow control means connected between the plurality of medium-pressure refrigerant pipes, an output high-pressure gas refrigerant pipe of the gas-liquid separator,
A first switching on-off valve for selectively connecting a plurality of gas refrigerant pipes connected to the indoor unit, a low-pressure refrigerant pipe connected to the outdoor unit, and a plurality of gas refrigerants connected to the indoor unit In a multi-chamber air conditioner having a non-azeotropic mixed refrigerant as a refrigerant, the output high-pressure gas refrigerant pipe of the gas-liquid separator is provided with a diversion controller having a second switching on-off valve for selectively connecting to a pipe. In the middle of a refrigerant pipe connecting each of the plurality of second switching valves, the output high-pressure liquid refrigerant pipe of the gas-liquid separator is connected by a gas-liquid mixing pipe.
A gas-liquid mixing section is provided for sucking up liquid refrigerant through an on-off valve opened during simultaneous cooling / heating operation mainly for cooling and mixing with the gas refrigerant in the output high-pressure gas refrigerant pipe of the gas-liquid separator. A multi-room air conditioner in which the efficiency of a refrigeration cycle is improved when an azeotropic mixed refrigerant is used, and the efficiency of the refrigeration cycle is not reduced even when a single refrigerant or an azeotropic mixed refrigerant is used as a refrigerant. The effect is obtained.

According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the bypass flow rate control means branches off from the high pressure or medium pressure refrigerant pipe upstream or downstream of the second flow rate control means of the branch flow controller. And a bypass pipe leading to a low-pressure refrigerant pipe connected to the outdoor unit through a plurality of medium-pressure refrigerant pipes and a supercooling heat exchanger that exchanges heat with the high-pressure liquid refrigerant pipe. In addition to the effects of the invention, there is an effect that the evaporating temperature of the cooling indoor heat exchanger is reduced to increase its capacity, and the efficiency of the refrigeration cycle is further improved.

According to an eighth aspect of the present invention, in the invention according to the seventh aspect, the first temperature detecting means for detecting the refrigerant temperature upstream of the bypass flow rate control means, and the refrigerant temperature downstream of the bypass flow rate control means. Temperature detecting means for detecting the pressure, first pressure detecting means for detecting the refrigerant pressure downstream of the flow control means for bypass, second pressure detecting means for detecting the discharge pressure of the compressor, Third to detect suction pressure
Pressure detecting means, a first and second temperature detecting means, a refrigerant composition calculating device for calculating the composition of the refrigerant from the detected value of the first pressure detecting means, a calculated value of the refrigerant composition calculating device, And a compressor / outdoor fan control device for controlling the operating frequency of the compressor and the number of revolutions of the outdoor fan according to the detection values of the second and third pressure detecting means. In addition to the effects of the present invention, the compressor and the outdoor fan can be controlled in accordance with the composition of the refrigerant in all operation modes, so that the efficiency of the refrigeration cycle is further improved.

According to a ninth aspect of the present invention, in the invention according to the seventh aspect, the first temperature detecting means for detecting the refrigerant temperature upstream of the bypass flow rate control means and the refrigerant temperature downstream of the bypass flow rate control means are detected. A second temperature detecting means,
A third method for detecting the high-pressure refrigerant temperature upstream of the second flow control means.
Temperature detecting means, first pressure detecting means for detecting the refrigerant pressure downstream of the bypass flow rate controlling means, fifth pressure detecting means for detecting the output high-pressure refrigerant pressure of the gas-liquid separator, A second temperature detecting means, a refrigerant composition calculating device for calculating the composition of the refrigerant from the detected value of the first pressure detecting means, a calculated value of the refrigerant composition calculating device, the fifth pressure detecting means, And a controller for controlling the opening of the second flow rate control means in accordance with the value detected by the temperature detection means. The opening degree of the second flow rate control means can be controlled accordingly, and the efficiency of the refrigeration cycle is further improved.

According to claim 10 of the present invention, claim 6
In the invention described above, fourth pressure detecting means for detecting the refrigerant pressure of the medium-pressure refrigerant pipe, fifth pressure detecting means for detecting the output high-pressure refrigerant pressure of the gas-liquid separator, and the fourth pressure detecting means And the third value according to the detection value of the fifth pressure detecting means.
And a controller for controlling the opening degree of the flow rate control means of the third embodiment. In addition to the effect of the invention according to claim 6, the opening degree of the third flow rate control means can be properly controlled in any operation mode, and the refrigeration cycle This has the effect of further improving the efficiency.

According to claim 11 of the present invention, claim 7
In the invention described above, fourth pressure detecting means for detecting the refrigerant pressure of the medium-pressure refrigerant pipe, fifth pressure detecting means for detecting the output high-pressure refrigerant pressure of the gas-liquid separator, and refrigerant downstream of the bypass flow rate control means Second temperature detecting means for detecting a temperature;
A fourth temperature detecting means for detecting a refrigerant temperature downstream of the subcooling heat exchanger in the bypass pipe, the fourth pressure detecting means, the fifth pressure detecting means, the second temperature detecting means, and a fourth temperature detecting means. A controller is provided for controlling the opening of the bypass flow rate control means in accordance with the value detected by the temperature detection means. There is an effect that the opening degree can be controlled and the efficiency of the refrigeration cycle is further improved.

According to claim 12 of the present invention, claim 7
In the described invention, a fifth temperature detecting means for detecting a refrigerant temperature between the indoor heat exchanger and the first flow control means,
Sixth temperature detecting means for detecting the refrigerant temperature of the gas refrigerant pipe connected to the indoor heat exchanger, fifth pressure detecting means for detecting the output high-pressure refrigerant pressure of the gas-liquid separator, and the fifth temperature The opening degree of the first flow rate control means according to the detection values of the detection means and the sixth temperature detection means, or the detected values and the saturated temperature value of the high pressure refrigerant pressure value detected by the fifth pressure detection means And a controller for controlling the first bypass flow rate control means so as to provide the optimal degree of superheat and subcooling to the indoor heat exchanger in all operation modes in addition to the effect of the invention described in claim 7. Control can be performed and the efficiency of the refrigeration cycle is further improved.

According to claim 13 of the present invention, claim 8
In the invention according to the ninth or ninth aspect, the calculated value of the refrigerant composition calculating device is corrected according to the capacity ratio between the cooling and the heating of the indoor unit. There is an effect that the composition can be obtained with higher accuracy and the refrigeration cycle in the cold main operation can be more appropriately operated.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a refrigerant circuit during a cold main operation according to a first embodiment of the present invention.

FIG. 2 is a partial side sectional view showing an example of a first dryness changing unit according to the first embodiment.

FIG. 3 is a phase equilibrium diagram showing a change in refrigerant composition by a first dryness changing unit according to the first embodiment.

FIG. 4 is a partial side sectional view showing an example of a second dryness changing unit according to the first embodiment.

FIG. 5 is a phase equilibrium diagram illustrating a change in refrigerant composition by a second dryness changing unit according to the first embodiment.

FIG. 6 is a schematic configuration diagram illustrating a refrigerant circuit during a cold main operation according to the second embodiment.

FIG. 7 is a partial side sectional view showing an example of a dryness changing unit according to the second embodiment.

FIG. 8 is a phase equilibrium diagram showing a change in refrigerant composition by means for changing the dryness of refrigerant in a gas-liquid separator according to the second embodiment.

FIG. 9 is a partial side sectional view showing another example of the dryness changing unit according to the second embodiment.

FIG. 10 is a schematic configuration diagram illustrating a refrigerant circuit during a cold main operation according to a third embodiment.

FIG. 11 is a partial side sectional view showing an internal configuration of a gas-liquid mixing unit according to a third embodiment.

FIG. 12 is a phase equilibrium diagram showing a change in the composition of the refrigerant in the gas-liquid mixing section according to the third embodiment.

FIG. 13 is a diagram showing the relationship between the dryness of the refrigerant at the inlet of the first indoor heat exchanger and the efficiency of the refrigeration cycle in the third embodiment.

FIG. 14 is a refrigerant circuit diagram of the multi-room air conditioner according to the fourth embodiment.

FIG. 15 is a refrigerant circuit diagram illustrating a flow of a refrigerant during a cold main operation according to the fourth embodiment.

FIG. 16 is a refrigerant circuit diagram showing the flow of refrigerant during a warm-up main operation according to a fourth embodiment.

FIG. 17 is a refrigerant circuit diagram illustrating a flow of a refrigerant during a cooling only operation according to the fourth embodiment.

FIG. 18 is a refrigerant circuit diagram illustrating a flow of a refrigerant during a heating only operation according to the fourth embodiment.

FIG. 19 is a refrigerant circuit diagram of the multi-room air conditioner according to the fifth embodiment.

FIG. 20 is a refrigerant circuit diagram showing the flow of the refrigerant during the cold main operation according to the fifth embodiment.

FIG. 21 is a refrigerant circuit diagram showing the flow of refrigerant during a warm-up main operation according to a fifth embodiment.

FIG. 22 is a refrigerant circuit diagram showing the flow of the refrigerant during the cooling only operation in the fifth embodiment.

FIG. 23 is a refrigerant circuit diagram illustrating a flow of a refrigerant during a heating only operation according to the fifth embodiment.

FIG. 24 is a block diagram showing a control system according to the fifth embodiment.

FIG. 25 is a flowchart showing an algorithm of a refrigerant composition calculation according to the fifth embodiment.

FIG. 26 is a flowchart illustrating a control algorithm of a compressor and an outdoor fan according to the fifth embodiment.

FIG. 27 is a flowchart showing a control algorithm of a second flow control unit according to the fifth embodiment.

FIG. 28 is a flowchart illustrating a control algorithm of a third flow control unit according to the fifth embodiment.

FIG. 29 is a flowchart illustrating a control algorithm of a bypass flow rate control unit according to the fifth embodiment.

FIG. 30 is a flowchart showing a control algorithm of a first flow rate control means according to the fifth embodiment.

FIG. 31 is a flowchart showing a control algorithm of a compressor and an outdoor fan according to the sixth embodiment.

FIG. 32 is a diagram illustrating a relationship between a capacity ratio between a heating indoor unit and a cooling indoor unit and a refrigerant composition flowing through the indoor unit according to the sixth embodiment.

FIG. 33 is a schematic configuration diagram showing a refrigerant circuit during a cooling main operation of a conventional multi-room air conditioner.

[Explanation of symbols]

Reference Signs List 1 compressor, 2 outdoor heat exchanger, 3 first indoor heat exchanger (condenser), 4 second indoor heat exchanger (evaporator), 5
Gas-liquid separator, 6 first decompression means, 7 second decompression means, 8 third decompression means, 9-18 refrigerant pipe, 19
1st dryness changing section (dryness changing means), 20 liquid mixing tubes (dryness changing means), 21 second dryness changing section (dryness changing means), 22 high pressure gas mixing pipe, 23 low pressure gas mixing Pipe (dryness changing means), 24 mixed gas decompression means (dryness changing means), 25 dryness changing means, 27
Hole, 28 liquid refrigerant, 29, 29a, 29b, 29c gas-liquid mixing section (dryness changing means), 30 gas-liquid mixing pipe (dryness changing means), 31 outdoor unit, 32 branch controller, 33a, 33b, 33c indoor Machine, 34 accumulator, 35 four-way valve, 36a, 36b, 36c, 36
d check valve, 37 low-pressure refrigerant pipe, 38 high-pressure refrigerant pipe, 39 high-pressure gas refrigerant pipe, 40 high-pressure liquid refrigerant pipe,
41 medium pressure refrigerant pipe, 42 second flow control means, 43
On-off valve, 44a, 44b, 44c First switching on-off valve, 45a, 45b, 45c Second switching on-off valve, 4
6 third flow control means, 47 low-pressure refrigerant pipe, 48
a, 48b, 48c indoor heat exchangers, 49a, 49b,
49c First flow control means, 50a, 50b, 50c
Gas refrigerant piping, 51a, 51b, 51c Medium pressure refrigerant piping, 52 outdoor fan, 53 bypass pipeline, 54 bypass flow rate control means, 55a, 55b, 55c First supercooling heat exchanger, 56 Second supercooling heat Exchanger, 57 first
Temperature detecting means, 58 second temperature detecting means, 59 first pressure detecting means, 60 second pressure detecting means, 61 third pressure detecting means, 62 third temperature detecting means, 63
Fourth temperature detecting means, 64 Fourth pressure detecting means, 65
Fifth pressure detecting means, 66a, 66b, 66c
Temperature detecting means, 67a, 67b, 67c sixth temperature detecting means, 68 refrigerant composition calculating device, 69 first controller (compressor / outdoor fan control device), 70 second controller, 71a to 71c 3 controllers.

Claims (13)

[Claims] 1. An air conditioner using a non-azeotropic mixed refrigerant as a refrigerant and comprising a refrigerant circuit returning from the compressor to a condenser, a decompression means, and an evaporator to the compressor, An air conditioner characterized in that at least one of the heat exchangers of the evaporator is provided with a dryness changing means for changing the dryness of the refrigerant. 2. A gas refrigerant having a plurality of indoor heat exchangers and a gas-liquid separator, wherein the gas refrigerant separated by the gas-liquid separator flows through a heating indoor heat exchanger, and the liquid refrigerant flows through a cooling indoor heat exchanger. In a multi-room air conditioner that performs simultaneous cooling and heating with a refrigerant circuit using a non-azeotropic mixed refrigerant, a liquid refrigerant is injected into the gas refrigerant flowing into the heating indoor heat exchanger, and a gas-liquid two-phase state is formed. A multi-room air conditioner comprising a dryness changing means for using a refrigerant. 3. A non-azeotropic mixed refrigerant is used as the refrigerant, and the gas refrigerant flows from the compressor to the gas-liquid separator through the outdoor heat exchanger and is separated by the gas-liquid separator. After passing through the heat exchanger and the first decompression means, the liquid refrigerant separated by the gas-liquid separator and passing through the third decompression means is joined, and then passed through the second decompression means and the second indoor heat exchanger. In a multi-chamber air conditioner provided with a refrigerant circuit returning to the compressor, a dryness changing means for injecting a liquid refrigerant into a gas refrigerant flowing into the first indoor heat exchanger and converting the gas refrigerant into a gas-liquid two-phase refrigerant A multi-room air conditioner characterized by having a. 4. The gas-liquid separator according to claim 3, wherein a hole through which a liquid refrigerant inside the gas-liquid separator flows is provided in the middle of a pipe connecting the gas-liquid separator and the first indoor heat exchanger. Multi-room air conditioner. 5. A gas refrigerant pipe connecting the gas-liquid separator and the first indoor heat exchanger, a liquid refrigerant pipe connecting the gas-liquid separator and the third pressure reducing means, and a gas-liquid mixing pipe. 4. The multi-room air conditioner according to claim 3, further comprising a gas-liquid mixing section that sucks up the liquid refrigerant and mixes the liquid refrigerant with the gas refrigerant in the gas refrigerant pipe. 6. An outdoor unit having a variable displacement compressor, a four-way valve, and an outdoor heat exchanger, a plurality of indoor units each connected to an indoor heat exchanger and first flow control means, and the outdoor unit High-pressure refrigerant pipes and low-pressure refrigerant pipes are connected by two refrigerant pipes, and the indoor heat exchangers of the plurality of indoor units and gas refrigerant pipes are connected by first flow control means and medium-pressure refrigerant pipes, respectively. A gas-liquid separator that separates refrigerant from a high-pressure refrigerant pipe connected to the outdoor unit into gas-liquid and outputs the refrigerant to a high-pressure gas refrigerant pipe and a high-pressure liquid refrigerant pipe; A second flow control unit connected between the refrigerant pipe and the plurality of medium-pressure refrigerant pipes connected to the indoor unit, a low-pressure refrigerant pipe connected to the outdoor unit, and the plurality of medium-pressure refrigerant pipes; The third stream connected between Quantity control means, a first switching valve for selectively connecting the output high-pressure gas refrigerant pipe of the gas-liquid separator and the plurality of gas refrigerant pipes connected to the indoor unit, and connected to the outdoor unit It has a second switching valve for selectively connecting the low-pressure refrigerant pipe and the plurality of gas refrigerant pipes connected to the indoor unit. In the air conditioner, the output high-pressure gas refrigerant pipe of the gas-liquid separator and the plurality of second
In the middle of the refrigerant pipe connecting the switching valve of
From the output high-pressure liquid refrigerant pipe of the gas-liquid separator, the liquid refrigerant is sucked up by a gas-liquid mixing pipe through an on-off valve that is opened during simultaneous cooling and heating operations mainly for cooling, and the output high-pressure gas refrigerant pipe of the gas-liquid separator A multi-room air conditioner, comprising a gas-liquid mixing section for mixing with a gas refrigerant. 7. A branch from a high-pressure or medium-pressure refrigerant pipe upstream or downstream of the second flow control means of the branch flow controller, and performs heat exchange with the bypass flow control means and a plurality of medium-pressure refrigerant pipes and high-pressure liquid refrigerant pipes. 7. The multi-room air conditioner according to claim 6, wherein a bypass pipe is provided to the low-pressure refrigerant pipe via the supercooling heat exchanger. 8. A first temperature detecting means for detecting a refrigerant temperature upstream of the bypass flow rate control means, a second temperature detecting means for detecting a refrigerant temperature downstream of the bypass flow rate control means, and a refrigerant downstream of the bypass flow rate control means. A first pressure detecting means for detecting a pressure, a second pressure detecting means for detecting a discharge pressure of the compressor, a third pressure detecting means for detecting a suction pressure of the compressor, and the first and second pressure detecting means. Temperature detecting means, and the first
A refrigerant composition calculating device for calculating the composition of the refrigerant from the detected value of the pressure detecting means, and a calculated value of the refrigerant composition calculating device, and the compressor of the compressor according to the detected values of the second and third pressure detecting means. The multi-room air conditioner according to claim 7, further comprising a compressor / outdoor fan control device for controlling an operation frequency and a rotation speed of the outdoor fan. 9. A first temperature detecting means for detecting a refrigerant temperature upstream of the bypass flow rate control means, a second temperature detecting means for detecting a refrigerant temperature downstream of the bypass flow rate control means,
Third temperature detecting means for detecting the high-pressure refrigerant temperature upstream of the flow control means, first pressure detecting means for detecting the refrigerant pressure downstream of the bypass flow control means, and detecting the output high-pressure refrigerant pressure of the gas-liquid separator. A fifth pressure detecting means for performing
A second temperature detecting means, a refrigerant composition calculating device for calculating a composition of the refrigerant from a detection value of the first pressure detecting means, a calculated value of the refrigerant composition calculating device, the fifth pressure detecting means, 8. The multi-room air conditioner according to claim 7, further comprising a controller that controls an opening of the second flow rate control means in accordance with a value detected by the temperature detection means. 10. A fourth pressure detecting means for detecting a refrigerant pressure of a medium-pressure refrigerant pipe, a fifth pressure detecting means for detecting an output high-pressure refrigerant pressure of a gas-liquid separator, and the fourth pressure detecting means. 7. A multi-room air conditioner according to claim 6, further comprising a controller for controlling an opening of said third flow control means in accordance with a value detected by said fifth pressure detection means. 11. A fourth pressure detecting means for detecting a refrigerant pressure of the medium pressure refrigerant pipe, a fifth pressure detecting means for detecting an output high pressure refrigerant pressure of the gas-liquid separator, and a refrigerant downstream of the bypass flow rate control means. Second temperature detecting means for detecting the temperature, fourth temperature detecting means for detecting the refrigerant temperature downstream of the subcooling heat exchanger in the bypass pipe, the fourth pressure detecting means, and the fifth pressure detecting means A controller for controlling an opening of the bypass flow rate control means in accordance with a value detected by the second temperature detection means and the fourth temperature detection means.
The multi-room air conditioner as described. 12. A fifth temperature detecting means for detecting a refrigerant temperature between the indoor heat exchanger and the first flow control means, and a refrigerant temperature of a gas refrigerant pipe connected to the indoor heat exchanger. Sixth temperature detection means, fifth pressure detection means for detecting the output high-pressure refrigerant pressure of the gas-liquid separator, detection values of the fifth temperature detection means and sixth temperature detection means, or these detection values And a controller for controlling an opening degree of the first flow rate control means in accordance with a saturation temperature value of the high pressure refrigerant pressure value detected by the fifth pressure detection means.
The multi-room air conditioner as described. 13. The multi-room air conditioner according to claim 8, wherein a calculation value of the refrigerant composition calculation device is corrected according to a capacity ratio between cooling and heating of the indoor unit.