JPH074779A - Simultaneous cooling-heating type multiple air conditioner - Google Patents

Abstract

PURPOSE:To improve draining of liquid from a heating unit by a method wherein a first pressure reducing valve is provided so that the pressure in a second liquid pipe becomes lower than that in a second gas pipe, and a multiple-effect separator and a supercooler are provided to send liquid refrigerant from the second liquid pipe to a cooling unit. CONSTITUTION:Time opening degree of a first pressure reducing valve 10 is regulated so that a pressure difference of liquid refrigerant separated by a gas-liquid separator l is created between a second gas pipe 4 and a second liquid pipe 5. A multiple-effect separator 11 is provided next to the gas-liquid separator 1 via the pressure reducing valve 10. Gas refrigerant is released to a first gas pipe 3 through a third pressure reducing valve 15 by the multiple- effect separator 11. On the other hand, liquid refrigerant flows through a solenoid valve 9 to a supercooler 13 where liquid refrigerant is cooled by its own liquid, and is sent to a cooling unit via the second liquid pipe 5. Thereby, lack of cooling and heating capacities can be solved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simultaneous cooling and heating type multi-air conditioner.

[0002]

2. Description of the Related Art FIG. 9 is a refrigerant circuit diagram of a conventional cooling / heating simultaneous multi-air conditioner. This circuit is composed of three blocks of circuits surrounded by alternate long and short dash lines in the figure and denoted by reference numerals (I), (II) and (III). The center (I) is the shunt controller circuit, the left (II) is the outdoor unit circuit, and the right (III) is the indoor unit circuit.

In the circuit in the shunt controller (I),
1 is a gas-liquid separator, 2 is a first liquid pipe connected to the outdoor unit (II) and reaches the gas-liquid separator 1, 3 is a first gas pipe connecting the outdoor unit (II) and the indoor unit (III) 4 is the gas side of the gas-liquid separator 1 and the indoor unit (I
II) a second gas pipe connecting 5 to the second liquid pipe connecting the liquid side of the gas-liquid separator 1 to the indoor unit (III), 6 an outdoor throttle,
8 and 9 are solenoid valves.

In the circuit in the outdoor unit (II), 31 is a compressor, 32 is a four-way switching valve connected to the compressor, 33 is an outdoor heat exchanger connected to the four-way switching valve, and 34 is the four-way switching valve. It is an accumulator connected to.

In the circuit in the indoor unit (III), four indoor unit units A, B, C and D are shown in the drawing, and each device is represented by a numeral symbol after each device. Character codes A, B, C and D are attached. 41A ~ 4
1D is an indoor unit throttle, 42A to 42D are indoor heat exchangers,
43A to 43D and 44A to 44D are cooling / heating switching valves. In addition, in the following description, when the individual units are not distinguished, they are represented by only numerical symbols, and character symbols (A to
The addition of D) is omitted. Next, the flow of the refrigerant in various modes in this device will be described.

During cooling, the high-temperature high-pressure gas refrigerant compressed by the compressor 31 of the outdoor unit (II) passes through the four-way switching valve 32 and enters the outdoor heat exchanger 33, where an outdoor fan (not shown) is used. The heat is exchanged with the air sent by, and the liquid refrigerant is cooled and enters the gas-liquid separator 1 through the first liquid pipe 2 of the diversion controller (I). At this time, the solenoid valves 7 and 8 are closed, and the liquid refrigerant is decompressed from the solenoid valve 9 and the second liquid pipe 5 by the throttle 41 of the operating unit (the throttle not operating is fully closed), and the indoor It enters the heat exchanger 42, where it is heated by air sent by an indoor fan (not shown) to become a low-pressure gas refrigerant, which passes through a switching valve 44 to a first
It returns to the compressor 31 via the gas pipe 3 and the four-way switching valve 32.

In the cooling main operation (the cooling operation of the indoor unit is more than that of the heating operation), the operation of the outdoor unit is the same as that of the cooling operation.
The high-pressure refrigerant that has entered the gas-liquid separator 1 from the liquid pipe 2 is gas-liquid separated, and the gas flows from the solenoid valve 8 through the second gas pipe 4 to the switching valve 43A of the heating unit (for example, A unit) to the indoor heat exchanger. It enters into 42A, is cooled here, becomes a liquid refrigerant, passes through the throttle 41A, and is a cooling unit (for example, B, C unit).
Go to. On the other hand, the liquid refrigerant separated by the gas-liquid separator 1 enters the indoor unit side from the second liquid pipe 5 via the solenoid valve 9, merges with the liquid refrigerant discharged from the heating unit, and is decompressed by the throttles 41B and 41C. The heat is exchanged and heated in the indoor heat exchangers 42B and 42C to become a low-pressure gas refrigerant, and returns from the switching valves 44B and 44C to the compressor 31 via the first gas pipe 3 and the four-way switching valve 32.

During heating, the four-way switching valve 32 switches, and the high-temperature high-pressure gas refrigerant enters the indoor heat exchanger 42 from the first gas pipe 3 through the switching valve 44 of the operating heating unit.
Here, heat is exchanged to become a liquid refrigerant, which is decompressed by the outdoor throttle 6 through the throttle 41, enters the outdoor heat exchanger 33 from the second gas pipe 4 through the electromagnetic valve 7 and the first liquid pipe 2, and exchanges heat there. Then, it becomes a low-pressure gas refrigerant and passes through the four-way switching valve 32 and the compressor 31.
Return to.

In heating-based operation, the operation of the outdoor unit is the same as that of heating. The high-temperature and high-pressure gas refrigerant is used as a switching valve 44A, B, C of a unit (for example, A, B, C) that is in heating operation.
To the indoor heat exchangers 42A, B, C, where they exchange heat to be cooled and become high-pressure liquid refrigerant, and the throttles 41A, B, C
The other one is decompressed by the throttle 41D of the unit that is performing the cooling operation, heated by the indoor heat exchanger 42D, becomes a low-pressure gas refrigerant, and enters the second gas pipe 4 through the switching valve 43D. The other liquid refrigerant is decompressed from the second liquid pipe 5 through the outdoor throttle 6, merges with the refrigerant coming from the cooling unit in the second gas pipe 4, and
The liquid pipe 2 goes to the outdoor unit (II) and returns to the compressor 31.

[0010]

In the prior art, the gas refrigerant mixes with the liquid refrigerant during cooling or during cooling, and the liquid refrigerant is not sufficiently supplied to the cooling unit. or,
When the indoor unit is on the upper side, the cooling capacity is insufficient due to the fact that the liquid refrigerant cannot be supplied to the cooling unit due to the head difference.

Further, during the simultaneous cooling and heating operation, the pressure difference between the high-pressure gas line (second gas pipe 4) and the liquid line (second liquid pipe 5) is small, and the liquid refrigerant of the heating unit goes to the liquid line side. It may become difficult to flow and the refrigerant may accumulate in the heat exchanger of the heating unit, resulting in insufficient heating capacity.

The present invention solves the above-mentioned drawbacks of the prior art, prevents the gas refrigerant from mixing with the liquid refrigerant during cooling and during the main cooling operation, and even if there is a head difference, sufficient liquid refrigerant is supplied to the cooling unit. By supplying the air conditioner, the cooling capacity shortage is solved.

Further, it is intended to solve the shortage of heating capacity by making it easier for the liquid refrigerant of the heating unit to flow to the liquid line side during the simultaneous cooling and heating operation.

In the conventional technique, the internal fluid is switched from the high temperature high pressure gas to the low temperature low pressure gas in the first gas pipe 3 every time the cooling main operation and the heating main operation are switched. If the piping is long, heat is absorbed by the piping when switching from the cooling type to the heating type, so that the heating unit does not rise well.

The present invention solves the above-mentioned drawbacks of the prior art and intends to make the heating unit start up quickly when the cooling main body is switched to the heating main body even if the piping is long.

In the prior art, when the pressures of the liquid line and the gas line become equal during the simultaneous cooling and heating operation, the discharge of the liquid from the heating unit becomes poor and the heating capacity becomes insufficient.

Further, when the intake superheat degree control is performed during heating or during heating-main operation, the refrigerant accumulates in the heating unit and the pressure rises when the cooling is excessive.

The present invention solves the above-mentioned drawbacks of the prior art and solves the shortage of heating capacity by improving the discharge of liquid from the heating unit during simultaneous cooling and heating operations.

Further, during heating or during heating-main operation,
Even if the suction superheat control is performed, the pressure of the heating unit is prevented from rising.

[0020]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and has one outdoor unit having a compressor, a four-way switching valve, and an outdoor heat exchanger, and an indoor heat exchanger. A plurality of indoor units, and a flow dividing unit for dividing the refrigerant into a plurality of indoor units provided between the outdoor unit and the indoor unit having a gas-liquid separator, the outdoor unit and the flow dividing unit, A first gas pipe and a first liquid pipe connected to the gas-liquid separator are connected to each other, and the same diversion unit and a plurality of indoor units are connected to the first gas pipe and the gas of the gas-liquid separator. The second that continues to the phase
Of the indoor heat exchanger is connected to one end of each indoor heat exchanger via the cooling / heating switching valve, and the second liquid pipe connected to the liquid phase region of the gas-liquid separator is connected to each of the indoor heat exchangers. A cooling / heating simultaneous multi-air conditioner having the following characteristics in a cooling / heating simultaneous multi-air conditioner in which the other end is connected through an indoor throttle and capable of cooling operation, heating operation, and simultaneous cooling / heating operation. .

(1) A multi-effect separator is provided on the second liquid pipe in the flow dividing unit with a first pressure reducing valve interposed between the second liquid pipe and the gas-liquid separator. A subcooler is provided on the indoor unit side of the multi-effect separator as a cooling source by decompressing a part of the liquid refrigerant branched from the pipe through a second pressure reducing valve, and a gas refrigerant from the subcooler and A third gas pipe is provided for guiding the gas refrigerant, which has passed through the third pressure reducing valve, from the multi-effect separator to the first gas pipe.

(2) The outdoor unit is provided with a switching means for constantly circulating the refrigerant in one direction with respect to the first gas pipe and the first liquid pipe.

(3) A first pressure sensor is provided in the second gas pipe in the flow dividing unit, and a second pressure sensor and a temperature sensor are provided in the second liquid pipe, so that during the cooling operation and the cooling main operation,
The first pressure reducing valve is controlled so that the pressure difference detected by the first and second pressure sensors becomes constant, and the degree of supercooling is detected from the detection values of the second pressure sensor and the temperature sensor. A controller is provided to control the third pressure reducing valve so as to be constant, and to control the second pressure reducing valve so that the degree of subcooling is constant during heating operation and heating-main operation.

(4) On the second liquid pipe in the flow dividing unit, between the gas-liquid separator and the gas-liquid separator, a fixed resistance is set when the heating and heating main operations are performed, and when the cooling and cooling main operations are performed, the resistance is open. A second gas-liquid separator is provided with the solenoid valve having
A subcooler that serves as a cooling source for decompressing a part of the liquid refrigerant branched from the second gas vapor-liquid separator of the liquid pipe of the second pipe through the second pressure reducing valve is provided on the indoor unit side of the second gas separator. A third gas pipe is provided for guiding the gas refrigerant from the cooler and the gas refrigerant that has passed through the third pressure reducing valve from the second gas-liquid separator to the first gas pipe,
Furthermore, a first pressure sensor is provided in the second gas pipe in the flow dividing unit, a second pressure sensor and a temperature sensor are provided in the second liquid pipe, and the first,
The third pressure reducing valve is controlled so that the pressure difference detected by the second pressure sensor becomes constant, and the degree of supercooling is detected from the detection values of the second pressure sensor and the temperature sensor. A controller for controlling the second pressure reducing valve is provided.

[0025]

In the invention including the means of the above item (1), the liquid refrigerant (which may contain a part of gas) separated by the gas-liquid separator passes through the first pressure reducing valve, A pressure difference is generated between the two gas pipes and the second liquid pipe. The opening of the first pressure reducing valve is adjusted so that a constant pressure difference is produced between the two pipes.
The liquid refrigerant slightly depressurized enters the multi-effect separator, and the gas content is released to a low pressure to reduce the dryness. In other words, it becomes a liquid with a small gas content and is further cooled by passing through the supercooler, and becomes a supercooled complete liquid and is supplied to the cooling unit.

In the invention including the means of the above item (2), by providing the second four-way switching valve in the outdoor unit, there is always a high-pressure gas, two-phase, liquid flow in the first liquid pipe, Flowing from the outdoor unit to the branch controller side, the first gas pipe is always a low-pressure two-phase gas refrigerant flow from the branch controller to the outdoor unit side.

In the invention including the means of the above item (3), the first pressure reducing valve is provided between the gas-liquid separator and the multi-effect separator during the cooling operation and the cooling main operation, and the second gas pipe is provided. Second
The pressure of the pressure sensor attached to the liquid pipe is input to control so that the pressure difference becomes constant. Also, input the pressure and temperature of the pressure sensor and temperature sensor attached to the second liquid pipe,
The third pressure reducing valve is controlled so that the degree of supercooling becomes constant. Further, during heating and during heating-main operation, pressure and temperature are input from a pressure sensor and a temperature sensor attached to the second liquid pipe, and the second pressure reducing valve is controlled so that the degree of supercooling becomes constant.

In the invention described in the above item (4), the third pressure reducing valve is controlled so that the pressure difference between the second gas pipe and the second liquid pipe becomes constant during the cooling operation and the cooling main operation.
Since the second pressure reducing valve is controlled so that the degree of supercooling becomes constant,
Good liquid drainage from the heating unit during simultaneous cold and warm operation. In addition, since the second pressure reducing valve is controlled so that the degree of subcooling is constant during heating and heating-main operation, stable heating capacity can be obtained.

[0029]

FIG. 1 is a refrigerant circuit diagram of a shunt controller according to a first embodiment of the present invention. In the figure, 10 is a first pressure reducing valve newly provided in the second liquid pipe 5 connected to the gas-liquid separator 1.
11 is a multi-effect separator provided on the pipe, 12 is a third gas pipe that connects the second liquid pipe 5 and the first gas pipe 3, and 13 is the same gas pipe 12 and the second liquid pipe 5. Supercooler provided between, 1
4 is a second pressure reducing valve provided at a portion where the third gas pipe 12 is branched from the second liquid pipe 5, and 15 is a second pressure reducing valve provided on the pipe connecting the multi-effect separator 11 to the third gas pipe 12. 3 pressure reducing valve. The configuration other than the above is the same as that of the conventional technique (FIG. 7), and thus the description thereof is omitted.

In this apparatus, when only the cooling is performed (the solenoid valves 7 and 8 are closed), the refrigerant flows from the gas-liquid separator 1 to the first pressure reducing valve 10
However, since it is only for cooling, the throttle is fully open. In the multi-effect separator 11, the gas refrigerant is allowed to escape from the third pressure reducing valve 15 to the first gas pipe 3. The liquid refrigerant is cooled by its own liquid in the subcooler 13 via the solenoid valve 9, and is sent to the cooling unit via the second liquid pipe 5. By flowing the liquid refrigerant into the first gas pipe 3 via the second pressure reducing valve 14, the liquid refrigerant is cooled.

When the cooling is mainly performed (only the solenoid valve 7 is closed), the gas refrigerant separated in the gas-liquid separator 1 is supplied from the second gas pipe 4 to the heating unit. On the other hand, the liquid refrigerant is depressurized by the pressure of the first pressure reducing valve. Therefore, there is a pressure difference between the high-pressure gas line (second gas pipe 4) and the second liquid pipe 5, and the first pressure reducing valve 10 is controlled so that this pressure difference becomes constant.
The flow of the liquid refrigerant thereafter is the same as that during cooling.

FIG. 2 is a refrigerant circuit diagram according to the second embodiment of the present invention. In the present embodiment, the cooling / heating switching valves 43 and 44 included in the indoor unit in the first embodiment (or the prior art of FIG. 7) described above are installed in the shunt controller of the first embodiment (FIG. 1). It was transferred. Therefore, the operation of this embodiment is substantially the same as that of the first embodiment, and the description thereof will be omitted.

The above-mentioned first and second embodiments relate to the invention of the item (1) of the means, in which the liquid refrigerant separated by the gas-liquid separator 1 passes through the first pressure reducing valve 10 to form a high pressure gas. A constant pressure difference is generated between the line (second gas pipe 4) and the second liquid pipe 5, and the liquid refrigerant with a small gas content is supercooled to become a complete liquid refrigerant, so that the cooling and heating capacity is improved. Can be increased.

FIG. 3 is a refrigerant system diagram of the flow dividing controller (I) and the outdoor unit (II) according to the third embodiment of the present invention. This circuit differs from the prior art (Fig. 7) in that the solenoid valves 7 and 8 of the conventional shunt controller (I) and the piping provided with the solenoid valve 7 are eliminated, and instead of the outdoor unit ( II) is provided with a second four-way switching valve 35, and further, in the flow dividing controller, the connection of the pipe provided with the outdoor throttle 6 is changed so that the second liquid pipe 5 and the first gas pipe 3 are connected. It is a point. Since two four-way switching valves are provided in this embodiment, the four-way switching valve 3 which has been conventionally provided is used.
2 is referred to as a first four-way switching valve in this embodiment. The parts other than the above are the same as those of the conventional technique, and therefore the description of the configuration is omitted.

In this embodiment, when operating only in cooling, the refrigerant is the compressor 31, the first four-way switching valve 32, the second
Four-way switching valve 35, first liquid pipe 2, gas-liquid separator 1, solenoid valve 9, indoor throttle 41, indoor heat exchanger 42, switching valve 44,
Returning to the compressor 31 via the first gas pipe 3, the second four-way switching valve 35, and the first four-way switching valve 32.

During the cooling main operation, the refrigerant is the compressor 3
1, the first four-way switching valve 32, the outdoor heat exchanger 33, the second four-way switching valve 35, and the first liquid pipe 2 to enter the gas-liquid separator 1, where they are separated into gas and liquid. The gas passes through the switching valve 43 of the heating unit and the indoor heat exchanger 42 of the heating unit.
Enter Liquid is solenoid valve 9 and indoor throttle 4 of cooling unit
1, the cooling unit switching valve 44, the first gas pipe 3, the second four-way switching valve 35, and the first four-way switching valve 32, and then returns to the compressor 31.

During the heating only operation or the heating-only operation, the first four-way switching valve 32 and the second four-way switching valve 35 are used.
Can be switched.

During heating operation, cooling is performed by the compressor 31, the first four-way switching valve 32, the second four-way switching valve 35, the first liquid pipe 2,
Gas-liquid separator 1, switching valve 43 for heating operation unit, indoor heat exchanger 42 for heating operation, indoor throttle 41, outdoor throttle 6, first gas pipe 3, second four-way switching valve 35, outdoor heat exchanger It returns to the compressor 31 through 33 and the 1st four-way switching valve 32.

During the heating-based operation, the refrigerant is the compressor 31,
First four-way switching valve 32, second four-way switching valve 35, first liquid pipe 2, gas-liquid separator 1, switching valve 43 of heating operation unit, indoor heat exchanger 42 of heating operation unit, indoor operation of heating operation unit Throttle 41, indoor throttle 4 of the cooling operation unit
1, the indoor heat exchanger 42 of the cooling operation unit, the switching valve 44 of the cooling operation unit, the first gas pipe 3, the second four-way switching valve 3
5, the outdoor heat exchanger 33, and the first four-way switching valve 32 are returned to the compressor 31. A part of the refrigerant branches from the outlet side of the indoor throttle 41 of the heating operation unit, and the outdoor throttle 6
And join the first gas pipe 3.

O of each switching valve in each of the above operation modes
Table 1 shows the N and OFF states.

[0041]

[Table 1]

FIG. 3 shows an outdoor unit (I) according to a fourth embodiment of the present invention.
It is a refrigerant circuit diagram of I). In this embodiment, the second four-way switching valve 35 in the third embodiment is replaced by four solenoid valves 36a-3.
6d, and the configuration of the parts other than those shown in the figure is the third
Same as the embodiment. Table 2 shows the ON / OFF of this solenoid valve.
It is based on. By controlling these solenoid valves, the same operation as the above-described four-way switching valve can be performed.

[0043]

[Table 2]

The third and fourth embodiments described above relate to the invention of the item (2) of the means, and by providing the outdoor unit with the second four-way switching valve or four electromagnetic valves,
High pressure gas, two-phase and liquid flows in the first liquid pipe 2 always flows from the outdoor unit to the diversion controller side, and in the first gas pipe 3 is always low-pressure two-phase, gas refrigerant and the flow is divided. The flow is from the controller to the outdoor unit side. That is, the flow of the refrigerant is switched on the outdoor unit side so that the pipes 2 and 3 are dedicated lines for high pressure and low pressure, respectively, and the flow of the refrigerant in the pipe is always unidirectional. Therefore, even if the piping is long, the heating unit can be quickly started up when switching from the cooling type to the heating type.

FIG. 5 is a system diagram of a shunt controller (I) according to a fifth embodiment of the present invention. This embodiment is a further improvement of the first embodiment. In this embodiment, the solenoid valve 7 and its piping are eliminated as compared with the first embodiment (FIG. 1). Also, the outdoor throttle 6 and its piping have been eliminated. Instead, the second gas pipe 4 is provided with the first pressure sensor 16, and the second liquid pipe 5 is provided with the second pressure sensor 17 and the temperature sensor 18, and the first pressure sensor 16, the second pressure sensor 17, and the temperature sensor 18 are provided. A controller 100 that controls opening and closing of the first pressure reducing valve 10, the second pressure reducing valve 14, and the third pressure reducing valve 15 based on a signal from

FIG. 6 is a control block diagram of this embodiment.
The control of this embodiment will be described based on this block diagram. 10
In 1, input the operation mode. Check either cooling operation, cooling operation, heating operation, or heating operation. In the case of cooling or cooling-main operation, the pressures of the first pressure sensor 16 and the second pressure sensor 17 are input at 102 to obtain the difference. The set value is input to 103. 10
The pressure difference and the set value are compared at 4 and at 105 the first pressure reducing valve 1
The opening of 0 is determined, and the opening is output at 106. At the same time when the pressure difference is detected, the pressure of the second pressure sensor 17 and the temperature of the temperature sensor 18 are input at 107 to obtain the degree of supercooling.
The set value is input to 108. These are compared in 109, the opening of the third pressure reducing valve 15 is determined in 110,
The opening is output at 111. When the operation mode input of 101 is heating and heating-main operation, the pressure of the second pressure sensor 17 and the temperature sensor 18 are detected by the supercooling degree detecting means 107.
Enter the temperature of and calculate the degree of supercooling. The set value is input to 108, the degree of supercooling and the set value are compared by the comparison means 109, 112 determines the opening of the second pressure reducing valve 14, and 113 outputs the opening. .

The fifth embodiment is related to the invention of the means (3), and in order to improve the liquid discharge of the heating unit during the simultaneous cooling / heating operation, the heating operation and the heating-main operation, a gas pipe is connected. Since a valve for providing a pressure difference to the liquid pipe is provided, stable heating capacity can be obtained by controlling the degree of supercooling.

FIG. 7 is a system diagram of the diversion controller (I) and the outdoor unit (II) according to the sixth embodiment of the present invention. The circuit of the outdoor unit (II) is the same as that shown in FIG. The diversion controller (I) of this embodiment is an improvement of the fifth embodiment shown in FIG. In FIG. 8, reference numeral 19 is an electromagnetic valve provided in place of the first pressure reducing valve 10 in FIG. This solenoid valve 19 is closed during heating and heating-main operation, and is open during cooling and cooling-main operation,
It also has a certain resistance. 20 is a second gas-liquid separator provided in place of the multi-effect separator 11 of FIG.
Reference numeral 00 is a controller provided in place of the controller 100 of FIG. This controller 200 is shown in FIG.
Unlike the above, it is also connected to the solenoid valve 8. The parts other than the above are the same as those in FIG. In the present embodiment, the first pressure reducing valve provided in the fifth embodiment (FIG. 5) is removed and the solenoid valve 19 is provided instead of the first pressure reducing valve, so that the pressure reducing number “first” is provided. The valve no longer exists,
The numbers “second” and “third” in the second pressure reducing valve 14 and the third pressure reducing valve 15 are left as they are as part of the names for comparison with the fifth embodiment.

FIG. 8 is a control block diagram of this embodiment.
The control of this embodiment will be described based on this block diagram. 20
Input the operation mode at 1. Check the cooling operation, cooling operation, heating operation, or heating operation here. At 202, the opening / closing of the solenoid valve is determined. The solenoid valve 8 is closed and the solenoid valve 19 is opened only in the cooling operation, the solenoid valves 8 and 19 are both opened in the cooling main operation, and the solenoid valve 8 is opened in the heating operation and the heating main operation. Decided to close,
It is output at 203.

In the case of cooling and cooling-main operation, at 204, the pressures of the first pressure sensor 16 and the second pressure sensor 17 are input to obtain the difference. The set value is input to 205. At 206, the pressure difference and the set value are compared, and at 207, the third
The opening of the pressure reducing valve 15 is determined, and the opening is output at 208. At the same time as detecting the pressure difference, the detection values of the second pressure sensor 17 and the temperature sensor 18 are input at 209 to obtain the degree of supercooling. The set value is input to 210. 21
These are compared in 1 and the opening of the second pressure reducing valve 14 is determined in 212, and the opening is output in 213.

When the operation mode input of 201 is heating or heating-main operation, the values of the second pressure sensor 17 and the temperature sensor 18 are input by the supercooling degree detecting means 209 to obtain the supercooling degree. The set value is input to 210, and the degree of supercooling and the set value are compared by the comparing means 211, and 212
Determines the opening of the second pressure reducing valve 14, and outputs the opening in 213.

The present embodiment relates to the invention of the item (4) of the means, and the third pressure reducing operation is performed so that the pressure difference between the second gas pipe 4 and the second liquid pipe 5 becomes constant during the cooling operation and the cooling main operation. Valve 1
5, the second pressure reducing valve 14 is controlled so that the degree of supercooling in the second liquid pipe 5 becomes constant, and the degree of supercooling in the second liquid pipe 5 becomes constant during heating and heating main operation. Thus, the second pressure reducing valve 14 is controlled. By doing so, the liquid can be well discharged to the heating unit during the simultaneous cold / warm operation, and a stable heating capacity can be obtained during the heating and the heating main operation.

[0053]

In the invention described in the paragraph (1) of the means, the first pressure reducing valve is provided so that the pressure of the second liquid pipe is always lower than the pressure of the second gas pipe, and the second liquid pipe is further provided. Since a multi-effect separator and a supercooler are provided in order to sufficiently send the liquid refrigerant from the cooling unit to the cooling unit, insufficient cooling capacity and insufficient heating capacity can be eliminated.

In the invention described in item (2) of the means,
The first liquid pipe and the first gas pipe are respectively dedicated lines for high pressure and low pressure, and a switching means such as a second four-way switching valve is provided in the outdoor unit so that the flow of the refrigerant in these pipes is always in the same direction. Therefore, the heating unit can be started up quickly when the operation mode is switched.

In the invention described in the section (3) of the means,
The first pressure reducing valve is controlled to provide a pressure difference between the second gas pipe and the second liquid pipe in order to improve the liquid discharge from the heating unit,
Further, since the third pressure reducing valve is controlled in order to keep the degree of supercooling constant, it is possible to eliminate the insufficient heating capacity. Further, during the heating operation and the heating-main operation, the second pressure reducing valve is controlled so that the degree of subcooling becomes constant, so that the pressure increase in the heating unit can be prevented.

In the invention described in item (4) of the means,
During cooling and cooling-main operation, the third pressure reducing valve is controlled so that the pressure difference between the second gas pipe and the second liquid pipe becomes constant, and the second pressure reducing valve is controlled so that the degree of subcooling becomes constant. Good liquid drainage from the heating unit during simultaneous cold and warm operation. In addition, since the second pressure reducing valve is controlled so that the degree of subcooling is constant during heating and heating-main operation, stable heating capacity can be obtained.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram according to a first embodiment of the present invention.

FIG. 2 is a refrigerant circuit diagram according to a second embodiment of the present invention.

FIG. 3 is a refrigerant circuit diagram according to a third embodiment of the present invention.

FIG. 4 is a refrigerant circuit diagram according to a fourth embodiment of the present invention.

FIG. 5 is a refrigerant circuit diagram according to a fifth embodiment of the present invention.

FIG. 6 is a control block diagram according to the fifth embodiment.

FIG. 7 is a refrigerant circuit diagram according to a sixth embodiment of the present invention.

FIG. 8 is a control block diagram according to the sixth embodiment.

FIG. 9 is a conventional simultaneous cooling and heating type multi-air conditioner.

[Explanation of symbols]

 1 gas-liquid separator 2 1st liquid pipe 3 1st gas pipe 4 2nd gas pipe 5 2nd liquid pipe 6 outdoor throttle 7 solenoid valve 8 solenoid valve 9 solenoid valve 10 first pressure reducing valve 11 multi-effect separator 12 second 3 gas pipe 13 supercooler 14 second pressure reducing valve 15 third pressure reducing valve 16 first pressure sensor 17 second pressure sensor 18 temperature sensor 19 solenoid valve 20 second gas-liquid separator 31 compressor 32 four-way switching valve, first Four-way switching valve 33 Outdoor heat exchanger 34 Accumulator 35 Second four-way switching valve 36a to 36d Electromagnetic valve 41A to 41D Indoor throttle 42A to 42D Indoor heat exchanger 43A to 43D Cooling / heating switching valve 44A to 44D Cooling / heating switching valve 100 Controller 200 Controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masami Ito, Nishi-Biwajima-cho, Nishi-Kasugai-gun, Aichi Prefecture, Asahi-cho, 3-chome, Air-conditioning Plant, Mitsubishi Heavy Industries (72) Inventor Takayuki Kobayashi Nishi-Bashijima-cho, Nishi-Kasugai-gun, Aichi Prefecture Asahi-cho 3-chome Mitsubishi Heavy Industries, Ltd. Air Conditioning Factory

Claims (4)

[Claims] 1. An outdoor unit having a compressor, a four-way switching valve, and an outdoor heat exchanger, a plurality of indoor units each having an indoor heat exchanger, and an outdoor unit having a gas-liquid separator. A first liquid pipe connecting the outdoor unit and the flow dividing unit to the first gas pipe and the gas-liquid separator. Each of the indoor heat exchanges is performed by connecting the same diversion unit and a plurality of indoor units to the first gas pipe and the second gas pipe connected to the gas phase region of the gas-liquid separator by connecting the pipes to each other. One end of each unit was connected via a heating / cooling switching valve, and the other end of each indoor heat exchanger was connected to a second liquid pipe connected to the liquid phase region of the gas-liquid separator via an indoor throttle. In the simultaneous cooling and heating multi-type air conditioner capable of performing cooling operation, cooling operation, heating operation and simultaneous cooling and heating operation, A multi-effect separator is provided on the second liquid pipe in the chamber by interposing a first pressure reducing valve between the gas-liquid separator and the multi-effect separator of the second liquid pipe, which is closer to the indoor unit than the multi-effect separator. Is provided with a subcooler which is used as a cooling source by decompressing a part of the liquid refrigerant branched from the same pipe through a second pressure reducing valve, and the gas refrigerant from the subcooler and the third effect separator from the multi-effect separator are provided. A simultaneous cooling and heating multi-air conditioner comprising a third gas pipe for guiding the gas refrigerant that has passed through a pressure reducing valve to the first gas pipe. 2. The heating / cooling device according to claim 1, further comprising switching means for constantly circulating the refrigerant in one direction with respect to the first gas pipe and the first liquid pipe in the outdoor unit. Simultaneous multi air conditioner. 3. A first pressure sensor is provided in a second gas pipe in the flow dividing unit, a second pressure sensor and a temperature sensor are provided in a second liquid pipe, and the first pressure sensor is provided in a cooling operation and a cooling main operation. , The first pressure reducing valve is controlled so that the pressure difference detected by the second pressure sensor becomes constant, and the degree of supercooling is detected from the detection values of the second pressure sensor and the temperature sensor. The controller for controlling the third pressure reducing valve to control the second pressure reducing valve so that the degree of subcooling is constant during heating operation and heating main operation. Simultaneous cooling and heating type multi-air conditioner. 4. An outdoor unit having a compressor, a four-way switching valve, and an outdoor heat exchanger, a plurality of indoor units each having an indoor heat exchanger, and an outdoor unit having a gas-liquid separator. A first liquid pipe connecting the outdoor unit and the flow dividing unit to the first gas pipe and the gas-liquid separator. Each of the indoor heat exchanges is performed by connecting the same diversion unit and a plurality of indoor units to the first gas pipe and the second gas pipe connected to the gas phase region of the gas-liquid separator by connecting the pipes to each other. One end of each unit was connected via a heating / cooling switching valve, and the other end of each indoor heat exchanger was connected to a second liquid pipe connected to the liquid phase region of the gas-liquid separator via an indoor throttle. In the simultaneous cooling and heating multi-type air conditioner capable of performing cooling operation, cooling operation, heating operation and simultaneous cooling and heating operation, On the second liquid pipe in the container, between the gas-liquid separator and a solenoid valve having a constant resistance, which is closed during heating and heating-main operation and open during cooling and cooling-main operation, is interposed. A second gas-liquid separator is provided, and a part of the liquid refrigerant branched from the second liquid pipe on the indoor unit side of the second gas pipe is decompressed through a second pressure reducing valve to be cooled. And a third gas pipe for guiding the gas refrigerant from the subcooler and the gas refrigerant from the second gas-liquid separator through the third pressure reducing valve to the first gas pipe. And a first pressure sensor in the second gas pipe in the flow dividing unit, and a second pressure sensor in the second gas pipe.
A second pressure sensor and a temperature sensor are provided in the liquid pipe, and the third pressure reducing valve is controlled so that the difference between the pressures detected by the first and second pressure sensors becomes constant during the cooling operation and the cooling main operation, Further, a simultaneous cooling and heating multi-type multi-function device is provided, which is provided with a controller for detecting the degree of supercooling from the detected values of the second pressure sensor and the temperature sensor and controlling the second pressure reducing valve so that the degree of supercooling is constant. Air conditioner.