JP2000161804A - Refrigerating air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize improvement in reliability by correcting a composition change of a non-azeotropic mixed refrigerant, and further make it possible to reuse a recovered refrigerant, thereby reducing cost. SOLUTION: A refrigerating air conditioner has a heat source unit with a large capacity, which is constituted of a combination of a plurality of heat source units, and allows a non-azeotropic mixed refrigerant to circulate as a refrigerant. This refrigerating air conditioner includes a main heat source unit 1a comprising a main compressor 2a, a main four-way directional control valve 3a, a main heat exchanger 4a, and a main liquid reservoring part 5a, a subordinate heat source unit 1b comprising a subordinate compressor 2b, a subordinate four-way directional control valve 3b, a subordinate heat exchanger 4b, and a subordinate main liquid reservoring part 5b, a liquid joining part 32 which allows a pipeline serving as a passage for a liquid refrigerant flowing out of the main heat exchanger 4a to be joined to a pipeline serving as a passage for a liquid refrigerant flowing out of the subordinate heat exchanger 4b, a gas joining part 31 which allows a pipeline serving as a passage for a gas refrigerant discharged from the main compressor 2a to be joined to a pipeline serving as a passage for a gas refrigerant discharged from the subordinate compressor 2b, and a composition detector 6 for detecting the circulating composition of the non-azeotropic mixed refrigerant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration / air-conditioning system in which a plurality of heat source units are combined to form a large-capacity heat source unit, and more particularly to a refrigeration / air-conditioning system for circulating a non-azeotropic refrigerant mixture as a refrigerant. .

[0002]

2. Description of the Related Art A conventional refrigerating air conditioner will be described below. FIG. 16 shows a plurality of heat source devices (here, 101a
And FIG. 101b) is a refrigerant circuit diagram of a conventional refrigeration and air-conditioning apparatus that constitutes a large-capacity heat source unit by combining the two units.

[0003] The refrigerant circuit of the conventional refrigeration and air-conditioning apparatus shown in FIG. 16 is composed of a main heat source unit 1 having a main compressor 102a, a main four-way switching valve 103a, a main heat exchanger 104a, and a main liquid reservoir 105a.
01a, a slave compressor 102b, a slave four-way switching valve 103b,
The secondary heat exchanger 104b includes a secondary heat source unit 101b having a secondary liquid storage part 105b, a use side heat exchanger 121, and a use side flow control valve 122, and a passage of the liquid refrigerant from the main heat exchanger 104a. Merging section 132 that joins a pipe that forms a pipe with a pipe that serves as a passage for the liquid refrigerant from the sub heat exchanger 104b.
And a gas merging section 131 that merges a pipe serving as a passage of a gas refrigerant from the main compressor 102a with a pipe serving as a passage of a gas refrigerant from the sub-compressor 102b. 101a and the slave heat source device 101b are connected in parallel.

In the refrigerant circuit configured as described above, a cooling operation and a heating operation are performed by flowing a refrigerant through internal piping. Hereinafter, the flow of the refrigerant during the cooling operation and the heating operation will be briefly described. Note that the solid arrows in FIG. 16 indicate the flow of the refrigerant during the cooling operation, and the dotted arrows indicate the flow of the refrigerant during the heating operation. Each of the illustrated four-way switching valves 103a and 103b is set for the cooling operation.

For example, when performing a cooling operation, the main compressor 1
02a, the high-temperature, high-pressure gas refrigerant flows out of the main four-way switching valve 1
After flowing through the main heat exchanger 104a through the heat exchanger 03a, the heat is radiated to become a high-pressure liquid refrigerant. Thereafter, the liquid refrigerant is supplied to the main heat source unit 10
It flows out of 1a and reaches the liquid junction 132. Slave heat source unit 1
Similarly, in 01b, the gas refrigerant passes through the slave compressor 102b, turns into a liquid refrigerant via the slave four-way switching valve 103b and the slave heat exchanger 104b, and reaches the liquid junction 132. Liquid junction 132
Are decompressed by the usage-side flow control device 122 to become low-temperature and low-pressure two-phase refrigerants. Further, by absorbing heat in the use-side heat exchanger 121, most of the two-phase refrigerant becomes gaseous.

Thereafter, the low-pressure gas refrigerant is divided into a main heat source device 101a and a sub heat source device 101b at a gas junction 131. The refrigerant flowing to the main heat source unit 101a flows to the main liquid reservoir 105a via the main four-way switching valve 103a, and the main liquid reservoir 10a
In 5a, the liquid refrigerant which has not been evaporated partially is separated, and only the gas refrigerant is returned to the main compressor 102a. Similarly, in the slave heat source device 101b, only the gas refrigerant is returned to the slave compressor 102b via the slave four-way switching valve 103b and the slave liquid reservoir 105b.

On the other hand, when performing the heating operation, the main compressor 10
The high-temperature, high-pressure gas refrigerant exiting from the main four-way switching valve 10
The gas reaches the gas junction 131 via 3a. Gas junction 131
Then, the gas refrigerant and the gas refrigerant flowing from the subordinate heat source device 101b also merge. The combined gas refrigerant is
The heat enters the use-side heat exchanger 121, where heat is radiated and condensed to become a high-pressure liquid refrigerant. The liquid refrigerant that has exited the use side heat exchanger 121 is decompressed by the use side flow control device 122 and becomes a low-pressure two-phase refrigerant.

Thereafter, the two-phase refrigerant is supplied to the liquid junction 132
And is divided into a main heat source unit 101a and a sub heat source unit 101b. The liquid refrigerant flowing into the main heat source unit 101a is supplied to the main heat exchanger 1
At 04a, most of the liquid part is endothermic and evaporated to become a gas refrigerant. Further, the refrigerant flows into the main liquid reservoir 105a via the main four-way switching valve 103a, and in the main liquid reservoir 105a, the liquid refrigerant that has been partially evaporated is separated and only the gas refrigerant is supplied to the main compressor 102a. return. On the other hand, the liquid refrigerant flowing to the sub heat source unit 101b is similarly processed in the sub heat source unit 101b, and only the gas refrigerant is returned to the sub compressor 102b in the sub liquid reservoir 105b.

As described above, in the conventional refrigeration and air-conditioning apparatus, the refrigerant flows through the piping inside the refrigerant circuit, and the main heat exchanger 104a,
The cooling operation and the heating operation are performed by exchanging heat in the slave heat exchanger 104b and the use-side heat exchanger 121.

[0010]

SUMMARY OF THE INVENTION However,
In a conventional refrigeration air conditioner, when a non-azeotropic mixed refrigerant obtained by mixing refrigerants having different boiling points is used as a refrigerant, for example,
Due to factors such as refrigerant stagnation in the indoor unit during heating operation (meaning that refrigerant is accumulated) and excess refrigerant stagnation in each heat source unit, uneven distribution of refrigerant may occur. Thereby, the mixing ratio of the individual refrigerants circulating in the refrigerant circuit (hereinafter, referred to as the mixing ratio)
(Referred to as "composition"), and the reliability of the compressor is reduced, thereby compromising the comfort of the refrigeration and air conditioning system.

Further, in the conventional refrigeration / air-conditioning apparatus, the composition of the non-azeotropic mixed refrigerant circulating in the refrigerant circuit changes in the same manner as described above due to leakage of the refrigerant and erroneous charging of the refrigerant. And the comfort of the refrigeration and air-conditioning system was impaired.

In the conventional refrigeration / air-conditioning apparatus, when the refrigerant is removed and the inside of the refrigerant circuit is repaired, if the refrigerant is a single refrigerant, the refrigerant is simply pumped down and the like. After recovery and restoration, the refrigerant can be reused. However, in a refrigerating air conditioner using a non-azeotropic mixed refrigerant, even if it is simply recovered, the composition of the refrigerant changes, and when the refrigerant is reused, a problem that normal operating characteristics cannot be ensured. there were. In addition, there is also a problem that a new refrigerant is used due to this, which leads to an increase in cost. Further, there is a possibility that the non-reusable recovered refrigerant may affect environmental problems such as global warming.

The present invention has been made in view of the above, and realizes improvement of reliability by correcting a change in composition of a non-azeotropic mixed refrigerant, and enables reuse of a recovered refrigerant. It is an object of the present invention to obtain a refrigeration and air-conditioning system that realizes cost reduction.

[0014]

Means for Solving the Problems The above-mentioned problems are solved,
In order to achieve the object, in a refrigeration / air-conditioning apparatus according to the present invention, at least one main compressor (corresponding to a main compressor 2a of an embodiment described later) and a main four-way switching valve (embodiment described later) , A main heat exchanger (corresponding to a main heat exchanger 4a in an embodiment described later), and a first main liquid reservoir (a main liquid reservoir 5a in an embodiment described later).
), A main heat source unit (corresponding to a main heat source unit 1a according to an embodiment described later), at least one sub-compressor (corresponding to a sub-compressor 2b according to an embodiment described later), and a four-way switching valve (Corresponding to a slave four-way switching valve 3a according to an embodiment described later), a slave heat exchanger (corresponding to a slave heat exchanger 4b according to an embodiment described later), and a first slave main liquid reservoir (described below as an embodiment). At least one secondary heat source unit (corresponding to a secondary liquid storage unit 5b of the embodiment) (corresponding to a secondary heat source unit 1b of an embodiment to be described later) and a pipe serving as a passage for liquid refrigerant flowing out of the main heat exchanger When,
A liquid merging portion (corresponding to a liquid merging portion 32 in an embodiment described later) for merging with a pipe serving as a passage for the liquid refrigerant flowing out of the slave heat exchanger, and a passage for the gas refrigerant discharged from the main compressor (A gas merge portion corresponding to a gas merge portion 31 in an embodiment described later) for joining a pipe that becomes a gas pipe and a pipe that becomes a passage for a gas refrigerant discharged from the slave compressor, and circulation of a non-azeotropic mixed refrigerant And a circulating composition detecting device (corresponding to a composition detecting unit 6 in an embodiment described later) for detecting the composition. And performing a cooling operation or a heating operation.

According to the present invention, the provision of the composition detector 6 makes it possible to always detect the true refrigerant circulation composition. Thereby, for example, even when the refrigerant stagnation into the indoor unit during heating, or due to factors such as excess refrigerant stagnation into each heat source unit, uneven distribution of the refrigerant occurs, even if the composition of the refrigerant circulating in the refrigerant circuit changes, Alternatively, even when the composition of the refrigerant changes due to factors such as refrigerant leakage and erroneous charging of the refrigerant, the change can be detected and the composition can be corrected.

In the refrigeration / air-conditioning apparatus according to the next invention, a flow control valve for adjusting the flow rate of the refrigerant (between the heat exchanger of at least one heat source unit and the liquid junction) is provided. Main flow control valve 8a, sub flow control valve 8
b).

According to the present invention, since each heat source unit is provided with the flow control valve (8a, 8b), the circulation amount of the refrigerant flowing through each heat source unit can be adjusted. Thereby, the uneven distribution of the surplus refrigerant is eliminated.

In the refrigeration / air-conditioning apparatus according to the next invention, a low-pressure pressure detecting means for detecting the pressure of the refrigerant (a main low-pressure detecting section 7a and a sub-low-pressure detecting section in an embodiment described later) for each heat source unit. And a temperature detecting means for detecting the temperature of the refrigerant (a main temperature detecting section 9 in an embodiment described later).
a, corresponding to the auxiliary temperature detector 9b), and adjusting the flow rate control valve based on the detected pressure and temperature to prevent the uneven distribution of the surplus refrigerant stagnating in each heat source device. Features.

According to the present invention, the degree of superheat of each heat exchanger is calculated from the detected pressure and temperature of the refrigerant. Here, when the degree of superheat on the slave heat source unit side is larger than that on the main heat source unit side, the main flow control valve is closed until the difference between the superheat degrees of the respective heat source units becomes smaller than a preset value, and Open the flow control valve. On the other hand, when the degree of superheat on the slave heat source unit side is smaller than that on the main heat source unit side, the main flow control valve is opened until the difference in the degree of superheat between the respective heat source units becomes smaller than a preset value. Close the flow control valve. Thereby, the uneven distribution of the surplus refrigerant is automatically eliminated.

In the refrigeration / air-conditioning apparatus according to the next invention, at least one second liquid storage section (embodiment described later) is provided between the heat exchanger in each heat source unit and the use side heat exchanger. Second main liquid reservoir 11a, second sub liquid reservoir 11b
By adjusting the flow rate control valve, a certain amount of surplus refrigerant stagnating in each heat source unit is secured while constantly keeping the refrigerant in a fluid state in the second liquid reservoir, It is characterized in that surplus refrigerant staying in the liquid reservoir is suppressed.

According to the present invention, the surplus refrigerant is always ensured in the second liquid reservoir, so that the first main liquid reservoir and the first liquid reservoir can be maintained.
The excess refrigerant is not retained in the secondary liquid reservoir. This allows
Fluctuations in the composition of the circulating refrigerant can be suppressed, and proper operation can always be performed.

In the refrigeration / air-conditioning apparatus according to the next invention, a refrigerant recovery port (corresponding to a refrigerant recovery port 14 in an embodiment described later) is provided in a pipe between the heat exchanger and the use side heat exchanger. And a first operating valve (a first main operating valve 12a, a first slave operating valve, and a second auxiliary operating valve in an embodiment described later) for controlling the refrigerant from the use side heat exchanger for each heat source unit. A second operation valve (corresponding to an operation valve 12b) for controlling refrigerant from a heat exchanger in the heat source device (a second operation valve according to an embodiment described later).
Of the main operation valve 13a and the second sub-operation valve 13b), and
Wherein the refrigerant is recovered outside the refrigerant circuit system without changing the composition of the non-azeotropic mixed refrigerant, and thereafter, the recovered refrigerant is reused.

According to the present invention, it is possible to recover the refrigerant without changing the refrigerant composition and to reuse the recovered refrigerant. Accordingly, even when the refrigerant is removed from the refrigerant circuit and the refrigerant circuit is repaired, a new refrigerant is not required after the repair, so that the cost can be reduced.

In the refrigeration / air-conditioning apparatus according to the next invention, a flow control means for controlling the flow rate of the refrigerant flowing into the use side heat exchanger (corresponding to a flow control valve control unit 15 in an embodiment described later). And recovering the refrigerant outside the heat source unit without changing the composition of the non-azeotropic mixed refrigerant, and then reusing the recovered refrigerant.

According to the present invention, almost all of the refrigerant can be recovered to the liquid line, the heat exchanger, or the gas line without changing the refrigerant composition in the heat source device. Further, after the restoration of each heat source unit is completed and the evacuation is completed, the first operation valve and the second operation valve are opened, so that the refrigerant can be recharged, and the refrigerant recycling rate is also reduced. Increase. As a result, even when the refrigerant is removed from the refrigerant circuit and the refrigerant circuit is repaired, a new refrigerant is not required after the repair, so that the cost can be reduced and the refrigerant can be easily recharged. In addition, the service time can be shortened.

In the refrigeration / air-conditioning apparatus according to the next invention, for each heat source unit, a service port (a first main service port 16a, an embodiment described later) for moving the refrigerant to another heat source unit is provided. A second main service port 17a, a third main service port 18a, a first sub service port 16b, a second sub service port 17b, and a third sub service port 18b). The refrigerant is recovered to another heat source without changing the composition of the refrigerant, and then the recovered refrigerant is reused.

According to the present invention, almost all of the refrigerant can be recovered to the liquid line, the heat exchanger, or the gas line without changing the refrigerant composition in the heat source device. Further, after the restoration of each heat source unit is completed and the evacuation is completed, the first operation valve and the second operation valve are opened, so that the refrigerant can be recharged, and the refrigerant recycling rate is also reduced. Increase. As a result, even when the refrigerant is removed from the refrigerant circuit and the refrigerant circuit is repaired, a new refrigerant is not required after the repair, so that the cost can be reduced and the refrigerant can be easily recharged. Thus, the service time can be shortened, and the emergency operation at the time of service can be performed.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a refrigeration / air-conditioning apparatus according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited by the embodiment.

Embodiment 1 FIG. 1 is a diagram showing Embodiment 1 of a refrigerant circuit diagram of a refrigeration / air-conditioning apparatus according to the present invention. This refrigerant circuit constitutes a large-capacity heat source device by combining a plurality of heat source devices using a non-azeotropic mixed refrigerant.

The refrigerant circuit shown in FIG. 1 is a main heat source unit having a main compressor 2a, a main four-way switching valve 3a, a main heat exchanger 4a, a main liquid reservoir 5a, a composition detecting section 6, and a main low pressure detecting section 7. 1a
And the slave compressor 2b, the slave four-way switching valve 3b, and the slave heat exchanger 4.
b, a sub-heat source unit 1b having a sub-liquid reservoir 5b, a use-side heat exchanger 21 for cooling and heating the room, and a use-side flow control valve 22 for controlling the flow rate of the refrigerant.

The refrigerant circuit includes a pipe serving as a passage for the liquid refrigerant flowing from the main heat exchanger 4a and a secondary heat exchanger 4b.
A liquid joining portion 32 for joining a pipe serving as a passage for the liquid refrigerant flowing from the main compressor 2a, and a pipe serving as a passage for the gas refrigerant from the main compressor 2a and a pipe serving as a passage for the gas refrigerant from the sub-compressor 2b. Two heat source units, that is, the main heat source unit 1a and the auxiliary heat source unit 1b are connected in parallel by the gas joining unit 31 to be joined.

The main compressor 2a on the side of the main heat source unit 1a and the auxiliary compressor 2b on the side of the auxiliary heat source unit 1b are both shown as one compressor. However, the present invention is not limited to this. The heat source unit only needs to have at least one capacity control type or constant speed type compressor. Further, when a plurality of compressors exist in each heat source unit, the combination may be the same or different. Absent. Further, in the present embodiment, for convenience, a case of a combination of two heat source devices (1a, 1b) will be described. However, a combination of two or more heat source devices operates in the same manner and provides the same effect. .

Next, the function of each part constituting the main heat source unit 1a will be described. The main compressor 2a outputs a high-temperature, high-pressure gas refrigerant. The main four-way switching valve 3a sets the path of the gas refrigerant according to the cooling operation and the heating operation. Main heat exchanger 4a
Performs heat exchange of each refrigerant (gas refrigerant, liquid refrigerant) according to the cooling / heating operation. The main liquid reservoir 5a separates the gas refrigerant and the liquid refrigerant, and returns only the gas refrigerant to the heat compressor 1a. Composition detector 6
Detects the composition of the non-azeotropic mixed refrigerant from the heat compressor 1a, that is, the mixing ratio of the individual refrigerants. The main low-pressure detector 7 detects the pressure of the two-phase refrigerant.

The components of the slave heat source unit 1b are the same as those described above and will not be described. Also,
In the present embodiment, the main heat source unit 1a includes a composition detection unit 6 that bypasses the space between the main compressor 2a discharge side and the main four-way switching valve 3a and the main liquid reservoir 5a.
It is different from the slave heat source unit 1b in that a main low pressure detection unit 7 provided between the main four-way switching valve 3a and the main compressor 2a is provided.

FIG. 2 is a diagram showing an example of the configuration of the composition detecting section 6. As shown in FIG. In FIG. 2, the composition detecting section 6 is provided between the discharge side of the main compressor 1 a and the main four-way switching valve 3 a via the composition detecting heat exchanger 41 and the pressure reducing section 42, and the first main liquid reservoir 5.
a, which is configured as a bypass circuit for flowing the refrigerant to
A first temperature detecting unit 43 and a second temperature detecting unit 44 are provided at the entrance and exit of the second unit, respectively.

In the refrigerant circuit configured as shown in FIG. 1, the cooling operation and the heating operation are performed by flowing the refrigerant through the internal piping. Hereinafter, the flow of the refrigerant during the cooling operation and the heating operation will be described with reference to FIG.

The solid arrows in FIG. 1 indicate the flow of the refrigerant during the cooling operation, and the dotted arrows indicate the flow of the refrigerant during the heating operation. Each of the illustrated four-way switching valves 3a and 3b is
This shows settings during the cooling operation. For example, when performing the heating operation, the main four-way switching valve 3a includes the main compressor 2a and the use side heat exchanger 21, and the main heat exchanger 4a and the main liquid reservoir. 5
are switched so as to connect to each other (the four-way switching valve 3b is similarly switched).

For example, when performing a cooling operation, the main compressor 2
The high-temperature, high-pressure gas refrigerant that has exited a flows through the main four-way switching valve 3a to the main heat exchanger 4a, where it radiates heat to become a high-pressure liquid refrigerant. Thereafter, the high-pressure liquid refrigerant is supplied to the main heat source unit 1a.
And flows to the liquid junction 32. Similarly, in the slave heat source unit 1b, the high-temperature, high-pressure gas refrigerant that has exited the slave compressor 2b becomes a high-pressure liquid refrigerant through the slave four-way switching valve 3b and the slave heat exchanger 4b. It flows out of 1b and reaches the liquid junction 32.

Each of the heat source devices 1a joined at the liquid joining section 32,
The liquid refrigerant from 1b flows to the use-side flow control device 22, where it is decompressed to a low-temperature, low-pressure two-phase refrigerant. Furthermore, most of the two-phase refrigerant becomes gaseous (gas refrigerant) by absorbing heat in the use-side heat exchanger 21.

Thereafter, the low-pressure gas refrigerant flows to the gas junction 31 where it is split into a main heat source unit 1a and a sub heat source unit 1b. The gas refrigerant that has flowed into the main heat source unit 1a flows through the main four-way switching valve 3a to the main liquid reservoir 5a, where the gas refrigerant and the liquid refrigerant that has been partially evaporated are separated. Then, only the gas refrigerant is returned to the main compressor 2a. Similarly, the gas refrigerant flowing to the main heat source unit 1b flows to the main liquid reservoir 5b via the sub four-way switching valve 3b, and returns only the gas refrigerant to the sub compressor 2b in the main liquid reservoir 5b.

In the present embodiment, by circulating the refrigerant as indicated by the solid line arrow, heat exchange is performed by the main heat exchanger 4a, the sub heat exchanger 4b, and the use side heat exchanger 21. , A cooling operation is being performed.

On the other hand, when performing the heating operation, the main compressor 2a
The high-temperature, high-pressure gas refrigerant that has flowed out flows out of the main heat source unit 1a through the main four-way switching valve 3a, and reaches the gas junction 31. Similarly, the high-temperature, high-pressure gas refrigerant that has exited the slave compressor 2b flows out of the slave heat source unit 1b via the slave four-way switching valve 3b, and reaches the gas junction 31.

In the gas merging section 31, the gas refrigerant flowing from the main heat source unit 1a and the gas refrigerant flowing from the sub heat source unit 1b merge. The merged gas refrigerant enters the use-side heat exchanger 21, where heat is released and condensed to become a high-pressure liquid refrigerant. The high-pressure liquid refrigerant that has exited the use-side heat exchanger 21 is decompressed by the use-side flow control device 22 and becomes a low-pressure two-phase refrigerant.

Thereafter, the two-phase refrigerant flows into the liquid junction 32 and is split into the main heat source unit 1a and the sub heat source unit 1b. Most of the liquid part of the liquid refrigerant flowing into the main heat source unit 1a is absorbed and evaporated in the main heat exchanger 4a to become a gas refrigerant. Further, the gas refrigerant flows into the main liquid reservoir 5a via the main four-way switching valve 3a, and separates the gas refrigerant and the partially unevaporated liquid refrigerant in the main liquid reservoir 5a. Is returned to the main compressor 2a. On the other hand, the liquid refrigerant flowing to the subordinate heat source
b, and only the gas refrigerant is returned to the secondary compressor 2b in the secondary liquid reservoir 5b.

In the present embodiment, by circulating the refrigerant as indicated by the dotted arrow, heat exchange is performed by the main heat exchanger 4a, the sub heat exchanger 4b, and the use side heat exchanger 21. Heating is being done.

Next, the flow of the refrigerant in the composition detecting section 6 will be described in detail with reference to FIGS.
As shown by solid arrows in FIG. 2, the high-temperature, high-pressure gas refrigerant that has exited from the main compressor 2a in the main heat source unit 1a is branched off from the refrigerant flowing to the main four-way switching valve 3 as described above. Some components flow toward the composition detector 6.

The gas refrigerant flowing to the composition detecting section 6 flows into the composition detecting heat exchanger 41 and exchanges heat with a low-temperature, low-pressure two-phase refrigerant flowing from a pressure reducing section 42 to be described later.
It becomes a high-pressure liquid refrigerant. The medium-temperature, high-pressure liquid refrigerant flowing through the composition detecting heat exchanger 41 flows into the decompression unit 42, where it is decompressed to become a low-temperature, low-pressure two-phase refrigerant, and again to the composition detecting heat exchanger 41. Inflows, and exchanges heat with the high-temperature, high-pressure gas refrigerant flowing from the main compressor 2a described above.
It becomes a low-pressure gas refrigerant. Then, the composition detection heat exchanger 4
The low-temperature, low-pressure gas refrigerant that has exited the first main reservoir 5a
Start flowing towards.

In the present embodiment, by circulating the refrigerant as described above, the detection of the refrigerant circulating composition of the non-azeotropic mixed refrigerant, that is, the detection of the mixture ratio of each refrigerant is performed.
Here, the principle of detecting the refrigerant circulation composition by the composition detection unit 6 will be described.

In the composition detecting section 6, the refrigerant is circulated as described above, the first temperature detecting section 43 detects the temperature of the liquid refrigerant before flowing into the pressure reducing section 42, and further detects the second temperature. The detecting section 44 detects the temperature of the liquid refrigerant flowing out of the pressure reducing section 42. Detection of refrigerant circulating composition of non-azeotropic mixed refrigerant is
The calculation is performed based on the temperatures of the two liquid refrigerants and the pressure of the two-phase refrigerant detected by the main low-pressure detector 7. In addition,
It is assumed that the detection of the refrigerant circulation composition is always performed while the power is turned on to the refrigeration / air-conditioning apparatus.

Hereinafter, a method of calculating the refrigerant circulation composition will be specifically described. For example, when a non-azeotropic triple refrigerant mixture called R407C is used as the circulating refrigerant, R32, R32
Since the three types of compositions 125 and R134a are unknowns, three equations are established and the unknown refrigerant circulation composition is calculated by solving the equations. First, the first formula can be determined by utilizing the fact that the addition of each of the three types of refrigerant circulation composition becomes '1'. At this time, R3
2, the composition of R125 and R134a is α
When expressed as 32, α125 and α134a, the following equation always holds.

Α32 + α125 + α134a = 1 (1)

Next, the second equation is as follows:
You can stand up from. FIG. 3 is a Mollier diagram showing a change in the state of the refrigerant in the composition detection unit 6. In this figure, the state of the high-pressure gas refrigerant that has exited the main compressor 2a is heat exchanged with the low-pressure refrigerant in the composition detection heat exchanger 41, and the liquefied state is the state in which the pressure is reduced in the decompression unit 42, The state in which the refrigerant has become a two-phase refrigerant indicates a state in which the refrigerant exchanges heat with a high-pressure refrigerant in the composition detection heat exchanger 41 to evaporate and gasify.

Since the states of FIG. 3 and the state of FIG. 3 have the same enthalpy, it is possible to establish an equation that enthalpies when α32 and α125 are unknowns and enthalpy are equal. That is, the enthalpy of the first temperature detector 43 is hl, the enthalpy of the
Is T11, and the temperature of the second temperature detector 44 is T1.
2. Assuming that the pressure of the main low pressure detecting section 7 is P13, the following equation is established.

Hl (α32, α125, T11) = ht (α32, α125, T12, P13) Expression (2)

Finally, the third equation states that as long as the filling composition initially charged into the refrigeration / air-conditioning system is R407C, a vapor-liquid equilibrium is established, the liquid stays in the main liquid reservoir 5a, and the refrigerant leaks. Even after the occurrence of, there is a certain relationship between the components of the refrigerant circulation composition. That is, assuming that A and B are constants, the following empirical formula for gas-liquid equilibrium composition is established.

Α32 = A × α125 + B (3)

As described above, the equations (1), (2),
And solving equation (3) yields α3
2, α125 and α134a can be obtained.

As described above, in the refrigeration / air-conditioning apparatus according to the present invention, in the refrigerant circuit in which a large-capacity heat source unit is formed by combining a plurality of heat source units using a non-azeotropic mixed refrigerant, the composition detecting unit 6 is used. Due to the provision, the true refrigerant circulation composition can be always detected. Accordingly, for example, uneven distribution of the refrigerant occurs due to factors such as refrigerant stagnation in the indoor unit during heating and excess refrigerant stagnation in each of the heat source units (4a, 4b), and the composition of the refrigerant circulating in the refrigerant circuit is reduced. Even if it changes, or if the composition of the refrigerant changes due to factors such as refrigerant leakage or refrigerant mis-filling, it is possible to detect the change and correct the composition, so that a highly reliable refrigeration and air conditioning system Is obtained.

In the first embodiment, the composition detecting section 6 is provided only in the main heat source unit 1a. However, in order to obtain the above-mentioned highly reliable refrigeration and air-conditioning apparatus, for example, FIG. As shown in the application example, the main composition detecting unit 6a and the auxiliary composition detecting unit 6b are connected to the main heat source unit 5a and the auxiliary heat source unit 5b.
It is good also as a structure provided for each of.

Embodiment 2 FIG. 5 is a diagram showing Embodiment 1 of a refrigerant circuit diagram of the refrigeration / air-conditioning apparatus according to the present invention. This refrigerant circuit also constitutes a large-capacity heat source device by combining a plurality of heat source devices using a non-azeotropic mixed refrigerant similarly to the first embodiment.

In FIG. 5, the configuration and operation of the refrigerant circuit and the flow (operation) of the refrigerant in the refrigeration / air-conditioning apparatus are basically the same as those described in the first embodiment. Are denoted by the same reference numerals and description thereof is omitted. In the second embodiment, the main heat exchanger 4a of the main heat source unit 1a
In that a main flow control valve 8a is provided in the path from the liquid junction part 32 to the liquid junction part 32, and a flow control valve 8b is further provided in the path from the sub heat exchanger 4b of the sub heat source unit 1b to the liquid junction part 32. This is different from the first embodiment.

In a refrigerating air conditioner using a non-azeotropic refrigerant mixture, for example, when excess refrigerant is generated during a heating operation, the ratio of low-boiling refrigerant in the circulating refrigerant becomes high,
In the surplus refrigerant that stays, the ratio of the high-boiling refrigerant is high. As described above, when the ratio of the low-boiling-point refrigerant in the circulating refrigerant is high, problems such as an increase in high-pressure are caused due to the characteristics of the non-azeotropic refrigerant mixture. In particular, in the case of a large-capacity model as in the present invention, the amount of the charged refrigerant increases, and the possibility of occurrence of the above-described problems tends to increase. Furthermore, if the amount of surplus refrigerant present in each heat source unit is unevenly distributed, that is, if the surplus refrigerant is not evenly distributed to each heat source unit, a large amount of high boiling point refrigerant will be present on one side, and consequently As a whole, the ratio of the low-boiling refrigerant in the circulating refrigerant increases.

Here, when surplus refrigerant is generated in the refrigerant circuit, the surplus refrigerant is supplied to each of the heat source units (1a, 1a, 1a, 1a).
An example in the case where the distribution is not uniform in b) will be described with reference to FIG. Note that the solid arrows in FIG. 5 indicate the flow of the refrigerant during the cooling operation, and the dotted arrows indicate the flow of the refrigerant during the heating operation.

For example, during the heating operation, the use side heat exchanger 21
Is returned to the main heat source unit 1a and the sub heat source unit 1b at the liquid junction 20. Ideally, the refrigerant is divided at a ratio corresponding to the refrigerant discharge amount discharged from the main compressor 2a and the sub compressor 2b. It is. However, the easiness of the flow of the refrigerant and the difficulty of the flow are likely to be mainly governed by the pressure loss in the piping, which largely depends on the refrigerant flow rate, the piping diameter, and the piping length of each compressor.

In FIG. 5, for example, when the pipe diameter from the liquid junction 32 to the main heat exchanger 4a is larger than the pipe diameter from the liquid junction 32 to the slave heat exchanger 4b, the same refrigerant flow rate is applied to those pipes. Flows, the pressure loss on the main heat source unit 1a side decreases, and the flow rate flowing on the main heat source unit 1a side increases. Therefore, the flow rate of the two-phase refrigerant flowing through the main heat exchanger 4a increases, and the amount of liquid refrigerant that cannot be evaporated there increases, and a large amount of high-boiling-point refrigerant is present in the main liquid reservoir 5a.

Further, on the side of the main heat exchanger 4a having a small pressure loss, since the pressure drop is small compared with the pressure of the liquid junction 32, the evaporation temperature of the main heat exchanger 4a acting as an evaporator also becomes high. When the evaporation temperature is high, the temperature difference with the fluid to be cooled (air in the air-cooled type, water in the water-cooled type) becomes small, so that the evaporation capacity also decreases. Accordingly, the liquid evaporation amount of the two-phase refrigerant also decreases, so that the dryness of the refrigerant exiting the main heat exchanger 4a tends to decrease. As a result, the unevaporated liquid refrigerant amount exceeds the refrigerant amount discharged from the main compressor or 2a, and the surplus refrigerant amount in the main liquid reservoir 5a increases.

On the other hand, when the pipe diameter from the liquid junction 32 to the main heat exchanger 4a is smaller than the pipe diameter from the liquid junction 32 to the slave heat exchanger 4b, the opposite is true. That is, in the refrigerant circuits having different pipe diameters from the liquid junction 32 to the heat exchangers (4a, 4b), the flow is divided at a ratio corresponding to the refrigerant discharge amount discharged from the main compressor 2a and the sub-compressor 2b. To get closer to the ideal,
The pressure loss from the liquid junction 32 to the outlet of each heat exchanger (4a, 4b) is made equal to the refrigerant discharge amount of each compressor (2a, 2b), and the evaporation temperature in each heat exchanger (4a, 4b) Need to be equivalent.

Therefore, in the second embodiment, the main flow control valve 8a and the sub flow control valve 8b are used to divide the refrigerant in an appropriate amount corresponding to the refrigerant discharge amount of the main compressor 2a and the sub compressor 2b. And These main flow control valves 8a,
By adjusting the sub flow control valve 8b, in the refrigerant circuit according to the second embodiment, the refrigerant is divided at a ratio commensurate with the refrigerant discharge amount discharged from the main compressor 1a and the sub compressor 1b, that is, the liquid equalization. Has been realized.

As described above, in the refrigeration / air-conditioning apparatus according to the present invention, in the refrigerant circuit constituting a large-capacity heat source unit by combining a plurality of heat source units using a non-azeotropic mixed refrigerant, each heat source unit (1a , 1b) with flow control valves (8a, 8
By providing b), the amount of circulation of the refrigerant flowing through each heat source device can be adjusted. Thereby, the uneven distribution of the surplus refrigerant is eliminated, and a more reliable refrigeration / air-conditioning apparatus can be obtained.

In the second embodiment, the main heat source unit 1a is provided with the main flow control valve 8a and the sub heat source unit 1b is provided with the flow control valve 8b. However, for example, in the application example of FIG. As shown, at least one of the heat source devices may be provided with a flow control valve. Also,
For the purpose of suppressing an increase in the size of the flow control valve, a flow control valve and a throttle device may be used in parallel. In addition, the composition detection unit 6
As in the first embodiment, each heat source unit (corresponding to FIG. 1) or one of the heat source units (corresponding to FIG. 4) may be provided, or a composition detecting unit 6 may be provided as in the related art. There may be no configuration.

Embodiment 3 FIG. 7 is a diagram showing Embodiment 3 of the refrigerant circuit diagram of the refrigeration / air-conditioning apparatus according to the present invention. This refrigerant circuit is also similar to the first and second embodiments,
A large-capacity heat source unit is constituted by combining a plurality of heat source units using a non-azeotropic mixed refrigerant.

In FIG. 7, the configuration of the refrigerant circuit and the flow (operation) of the refrigerant in the refrigeration / air-conditioning apparatus are basically the same as those described in the first and second embodiments. Therefore, the same components are denoted by the same reference numerals, and description thereof is omitted. In the third embodiment, the third heat exchanger 4a is provided between the main four-way switching valve 3a and the main heat exchanger 4a of the main heat source unit 1a.
The second embodiment differs from the second embodiment in that a third sub-temperature detector 9b is provided between the sub-four-way switching valve 3b and the sub-heat exchanger 4b of the sub-heat source unit 1b. Is different.

Although not shown in FIG. 7,
The main heat exchanger superheat degree calculating device 10 includes the main low-pressure pressure detecting section 7a and the third main temperature detecting section 9a in the main heat source unit 1a.
Similarly, the sub-low pressure detecting unit 7b and the third sub-temperature detecting unit 9b in the sub-heat source unit 1b are collectively referred to as a sub-heat exchanger superheat degree calculating device 10b.

Here, the main heat exchanger 4
is larger than the pipe diameter from the liquid junction 20 to the sub heat exchanger 4b, that is, the pressure loss on the main heat source unit 1a side is smaller for the same refrigerant circulation amount, and the main heat source unit 1
An example of a case where a large amount of surplus refrigerant is ubiquitous on the a side will be described as an example of liquid leveling control in which refrigerant is diverted at a ratio commensurate with the refrigerant discharge amount discharged from each compressor (1a, 1b).

FIG. 8 is an example of a liquid level control block diagram showing liquid level control according to the third embodiment. As described in the second embodiment, in order to perform the liquid leveling control, the refrigerant circulating amount (discharge amount) of each compressor (2a, 2b) is changed from the liquid junction 32 to each of the heat exchangers (4a, 4b) The pressure loss to the outlet, that is, the degree of superheat may be made equal. Therefore,
The main heat exchanger superheat degree calculation device 10a is configured to detect the low pressure detected by the main low pressure detection unit 7a and the third main temperature detection unit 9a.
The superheat degree SH of the main heat exchanger 4a
a is calculated.

Similarly, the subheat exchanger superheat degree calculating device 10b
Calculates the degree of superheat SHb of the sub heat exchanger 4b from the low pressure detected by the sub low pressure detector 7b and the temperature detected by the third sub temperature detector 9b. When the absolute difference between the two superheat degrees Sha and SHb is smaller than a preset value (FIG. 8, S1, Yes), the operation is continued as it is (S2), but when it is large (S1). , N
o), liquid leveling control described below is performed (S3).

FIG. 9 is a diagram showing the relationship between the refrigerant circulation amount of each compressor (2a, 2b) and the pressure loss, the evaporation temperature, the degree of superheat of the heat exchanger, or the liquid amount in the liquid reservoir ((a), (b), respectively). ),
(Equivalent to (c) and (d)). For example, the main heat exchanger 4
When the absolute difference between the superheat degree SHa of the subheat exchanger a and the superheat degree SHb of the sub heat exchanger 4b is larger than a preset value, the main heat source unit 1a reduces the main flow rate so that the difference between the superheat degrees becomes smaller. Adjust the control valve 8a (Gra → G in FIG. 9C).
ra ′), and increases the pressure loss on the main heat source 1a side (FIG. 9).
(Equivalent to Gra → Gra ′), and the evaporation temperature is reduced (Equivalent to Gra → Gra ′ in FIG. 9B).

As a result, the degree of superheat, pressure loss, and evaporation temperature of the main heat source unit 1a become equal to the degree of superheat, pressure loss, and evaporation temperature of the sub heat source unit 1b, and liquid leveling control is performed. Become. That is, as shown in FIG. 9D, the liquid amounts in the liquid reservoirs (5a, 5b) become equal, and the excess refrigerant is not unevenly distributed in each heat source unit.

As described above, in the refrigerant circuit of the refrigeration / air-conditioning apparatus according to the third embodiment, when the superheat degree of the sub heat source unit 1b is larger than that of the main heat source unit 1a, the main flow control valve 8a is connected to each heat source. The valve is closed until the difference in the degree of superheat of the machine becomes smaller than a preset value, and the dependent flow control valve 8b is opened. on the other hand,
When the superheat degree of the sub heat source unit 1b side is smaller than that of the main heat source unit 1a, the main flow control valve 8a is opened until the difference in superheat degree of each heat source unit becomes smaller than a preset value, The slave flow control valve 8b is closed. Thereby, the uneven distribution of the surplus refrigerant is eliminated, and a more reliable refrigeration / air-conditioning apparatus can be obtained.

In the third embodiment, the main heat source unit 1a is provided with the main flow control valve 8a and the sub heat source unit 1b is provided with the flow control valve 8b. For example, at least one of the heat sources It is good also as composition provided with a flow control valve only in a machine.

Embodiment 4 FIG. 10 is a diagram showing Embodiment 4 of a refrigerant circuit diagram of a refrigeration / air-conditioning apparatus according to the present invention. This refrigerant circuit also constitutes a large-capacity heat source device by combining a plurality of heat source devices using a non-azeotropic mixed refrigerant similarly to the first, second, and third embodiments.

In FIG. 10, the refrigerant circuit configuration and the flow (operation) of the refrigerant in the refrigeration / air-conditioning apparatus are basically the same as those described in the first, second, and third embodiments. The same components are denoted by the same reference numerals and description thereof will be omitted. In the fourth embodiment, the main heat source unit 1a
A second main liquid reservoir 11a between the main heat exchanger 4a and the liquid junction 32, and further comprises a sub heat exchanger 4 of the sub heat source unit 1b.
The third embodiment is different from the third embodiment in that a second auxiliary liquid storage portion 11b is provided between the liquid junction portion 32 and the liquid junction portion 32b.

In the third embodiment, as described above, the refrigerant is diverted at a ratio commensurate with the amount of refrigerant discharged from the main compressor 2a and the sub-compressor 2b, and the main liquid reservoir 5 in the main heat source unit 1a is divided.
The excess refrigerant is evenly present in the auxiliary liquid reservoir a and the auxiliary liquid reservoir 5b in the auxiliary heat source device 1b, thereby suppressing fluctuations in the circulation composition of the refrigerant. On the other hand, in the fourth embodiment, the second main liquid reservoir 11
a and the second auxiliary liquid reservoir 11b are provided so that the excess refrigerant does not accumulate in the main liquid reservoir 5a and the auxiliary liquid reservoir 5b where the excess refrigerant tends to accumulate. By keeping a certain amount of surplus refrigerant in the second auxiliary liquid reservoir 11b while always keeping the refrigerant in a fluidized state, it is intended to suppress fluctuations in the circulation composition of the refrigerant. This makes it possible to always maintain an appropriate operating state.

Here, the surplus refrigerant does not stay in each of the liquid reservoirs (5a, 5b), and a certain amount of fluid that is constantly flowing in the second main liquid reservoir 11a and the second auxiliary liquid reservoir 11b. The control for suppressing the fluctuation of the circulation composition of the refrigerant by securing the liquid refrigerant will be specifically described.

FIG. 11 shows liquid level control according to the fourth embodiment.
That is, it is an example of a liquid leveling control block diagram showing control for suppressing fluctuations in the circulation composition of the refrigerant. As described in the second and third embodiments, in order to perform liquid leveling control, the refrigerant circulating amount (discharge amount) of each of the compressors (2a, 2b) is changed from the liquid merging section 32 to each of the heat exchangers ( 4a, 4b) The pressure loss to the outlet, that is, the degree of superheat may be made equal.

Therefore, the main heat exchanger superheat degree computing device 10a
Calculates the superheat degree SHA of the main heat exchanger 4a from the low pressure detected by the main low pressure detector 7a and the temperature detected by the third main temperature detector 9a. Similarly, the subheat exchanger superheat degree calculation device 10b calculates the temperature of the subheat exchanger 4b based on the low pressure detected by the sub low pressure detector 7b and the temperature detected by the third subtemperature detector 9b. The degree of superheat SHb is calculated.

When the superheat degree Sha is smaller than the preset value A (FIG. 11, S11, N
o), the main flow control valve 8a is closed (S12), and if larger (S11, Yes), the main flow control valve 8a is opened (S13). Similarly, when the superheat degree SHb is smaller than the preset value A (S14, No), the slave flow control valve 8b is closed (S15), and when it is larger (S14, Yes). Open the slave flow control valve 8b (S
16).

As described above, in the refrigerant circuit of the refrigerating and air-conditioning apparatus according to the fourth embodiment, the two superheat degrees SHa and SHb
Is smaller than the preset value A, the degree of superheat (S) is always at the outlet of each heat exchanger (4a, 4b).
H) is secured, and the excess refrigerant does not stay in the main liquid reservoir 5a and the sub liquid reservoir 5b. As a result, the composition fluctuation of the circulating refrigerant can be suppressed, the proper operation can be performed at all times, and a more reliable refrigeration / air-conditioning apparatus can be obtained.

In the fourth embodiment, a second main liquid reservoir 11a is provided between main heat exchanger 4a and liquid junction 32, and a second liquid reservoir 11a is provided between slave heat exchanger 4b and liquid junction 32. Although the configuration includes the subordinate liquid reservoir 11b, for example, a configuration in which a second liquid reservoir is provided between the liquid junction 32 and the use-side heat exchanger 21 may be used. Further, the present invention can also be implemented in a refrigerant circuit without the composition detection unit 6.

Embodiment 5 FIG. 12 is a diagram showing Embodiment 5 of the refrigerant circuit diagram of the refrigeration / air-conditioning apparatus according to the present invention. As in the first embodiment, this refrigerant circuit combines a plurality of heat source devices using a non-azeotropic mixed refrigerant to constitute a large-capacity heat source device.

In FIG. 12, the configuration of the refrigerant circuit and the flow (operation) of the refrigerant in the refrigeration / air-conditioning apparatus are basically the same as those described in the first embodiment. Are denoted by the same reference numerals and description thereof is omitted. In the fifth embodiment, the main heat source unit 1a includes the first main operation valve 12a between the main four-way switching valve 3a and the use side heat exchanger 91, and further includes the main heat exchanger 4a and the use side heat exchange. A second main operating valve 13a between the second main operating valve 13a and the first sub-operating valve 12b between the four-way switching valve 3b and the use side heat exchanger 91 in the sub heat source unit 1b. Prepared,
Further, a point that a second slave valve 13b is provided between the slave heat exchanger 4b and the use side heat exchanger 91,
4 is different from the configuration of the first embodiment.

Generally, the refrigerant is removed from the refrigerant circuit,
In the case of performing a heavy service such as repairing the refrigerant circuit, if the refrigerant used is a single refrigerant such as R22, the refrigeration air conditioner simply performs pump down or the like and executes the refrigerant. Collect. Then, after repairing the refrigerant circuit, the recovered refrigerant is reused. However, if the refrigerant used is a non-azeotropic mixed refrigerant such as R407C, it is difficult to reuse even if it is simply recovered because refrigerants having different boiling points are mixed.

The reason that it is difficult to recycle is that, for example, when surplus refrigerant is generated during the heating operation, the ratio of the low-boiling refrigerant in the circulating refrigerant becomes high, and the excess refrigerant stagnating becomes high. A state in which the ratio of the boiling point refrigerant is high. In this case, even if the circulating refrigerant is recovered from the low-pressure liquid line to the outside of the circuit system, the recovered refrigerant has a composition in which the ratio of the low-boiling refrigerant is high, that is, the refrigerant composition has changed, If the refrigerant is reused, normal operating characteristics cannot be secured.

Therefore, in the fifth embodiment, the operation of each of the heat source units (1a, 1b) during the operation in which the circulation composition does not change, for example, the cooling operation (the operation in which the excess refrigerant is less likely to change the composition) is performed. Refrigerant is recovered from a refrigerant recovery port 14 provided in a liquid line between each heat exchanger (4a, 4b) and the use-side heat exchanger 21 to an empty tank that has been evacuated in advance. By doing so, the refrigerant can be recovered without a change in composition, and thus, after the refrigerant circuit is restored, the recovered refrigerant can be reused.

Further, during the recovery, the operation becomes impossible due to the shortage of the refrigerant, and even if the refrigerant cannot be sufficiently recovered, the composition in the liquid pipe is changed by closing the second operation valves 10a and 10b after the operation is stopped. No reusable refrigerant can be recovered.

As described above, in the refrigerant circuit of the refrigeration / air-conditioning apparatus according to the fifth embodiment, it is possible to collect the refrigerant without changing the refrigerant composition and to reuse the collected refrigerant. . As a result, even when the refrigerant is removed from the refrigerant circuit and the refrigerant circuit is repaired, a new refrigerant is not required after the repair, so that a refrigeration / air-conditioning apparatus that realizes cost reduction can be obtained. Furthermore, in order not to dispose of the recovered refrigerant, that is, to reuse it,
It can also solve environmental problems such as global warming.

In the fifth embodiment, the composition detector 6
Even in a refrigerant circuit having no refrigerant, it is possible to recover the refrigerant without changing the refrigerant composition and to reuse the recovered refrigerant. Further, in a refrigerant circuit configured by a single heat source device instead of a plurality of heat source devices (corresponding to 1a and 1b in the present embodiment) or a refrigerant circuit having the configuration of the second, third, and fourth embodiments. Also, by providing the same configuration as in the fifth embodiment, the same effect can be obtained.

Embodiment 6 FIG. FIG. 13 is a diagram showing Embodiment 6 of the refrigerant circuit diagram of the refrigeration / air-conditioning apparatus according to the present invention. This refrigerant circuit also constitutes a large-capacity heat source device by combining a plurality of heat source devices using a non-azeotropic mixed refrigerant as in the other embodiments.

In FIG. 13, the refrigerant circuit configuration and the flow (operation) of the refrigerant in the refrigeration / air-conditioning apparatus are basically the same as the configurations and operations described in the first and fifth embodiments. The configuration is denoted by the same reference numeral, and the description is omitted. In the sixth embodiment, the use side flow control valve 2
The second embodiment is different from the fifth embodiment in that a flow control valve control unit 15 capable of adjusting the pressure 2 is provided.

In the sixth embodiment, when performing a heavy service such as removing the refrigerant from the refrigerant circuit and repairing the refrigerant circuit, if the recovery method of the fifth embodiment described above is implemented, Even in the case of a non-azeotropic mixed refrigerant, the refrigerant can be reused after repair. However, this collection method requires the preparation of an empty tank that has been evacuated,
There is a limit to the amount of refrigerant that can be recovered. On the other hand, each heat source unit (1
At the time of repairing a and 1b), it is only necessary to recover the refrigerant from inside the heat source device. Therefore, the recovered refrigerant only needs to be moved to other than the heat source device without changing the composition.

Therefore, in the sixth embodiment, first, an operation in which the circulation composition does not change, for example, a cooling operation (operation in which the amount of excess refrigerant is small and the composition does not easily change) is performed.
2a and the slave valve 12b are closed. Next, under the control of the flow control valve control means 15, the use side flow control valve 22 is controlled more loosely than usual, and the outlet of the use side heat exchanger 21 is controlled to be slightly wet. Finally, each heat source unit is determined based on information such as whether the low pressure during the recovery operation is near vacuum, whether the liquid line is sufficiently subcooled, or if there is no liquid amount in each of the liquid reservoirs (5a, 5b). When it is detected from (1a, 1b) that the refrigerant recovery has been completed, the second
The main operation valve 10a and the second slave operation valve 10b are closed.

As described above, in the refrigerant circuit of the refrigeration / air-conditioning apparatus according to the sixth embodiment, almost all of the refrigerant is transferred to the liquid line and to the heat exchange using the above-described recovery method without changing the refrigerant composition in the heat source device. It can be collected in the vessel 21 or in a gas line. After the restoration of each heat source unit is completed and the evacuation is completed, the first main operation valve 12a and the second
Of the main operation valve 13a, the first slave operation valve 12b, and the second
, The refrigerant can be recharged, and the refrigerant recycling rate increases.

As a result, even when the refrigerant circuit is removed from the refrigerant circuit and the refrigerant circuit is repaired, a new refrigerant is not required after the repair, so that the cost can be reduced and the refrigerant can be easily recharged. By doing so, a refrigeration and air-conditioning system that can shorten service time can be obtained. Furthermore, since the collected refrigerant is not disposed of,
That is, environmental problems such as global warming can be solved by reuse.

In the sixth embodiment, the composition detector 6
Even in a refrigerant circuit having no refrigerant, it is possible to recover the refrigerant without changing the refrigerant composition and to reuse the recovered refrigerant. Further, in a refrigerant circuit configured by a single heat source device instead of a plurality of heat source devices (corresponding to 1a and 1b in the present embodiment) or a refrigerant circuit having the configuration of the second, third, and fourth embodiments. Also, by providing the same configuration as in the sixth embodiment, the same effect can be obtained.

Embodiment 7 FIG. 14 and 15 show a refrigeration and air-conditioning apparatus according to a seventh embodiment of the present invention.
FIG. This refrigerant circuit also constitutes a large-capacity heat source device by combining a plurality of heat source devices using a non-azeotropic mixed refrigerant as in the other embodiments. FIG. 14 is a refrigerant circuit diagram showing the flow of the refrigerant during the cooling operation, and FIG. 15 is a refrigerant circuit diagram showing the flow of the refrigerant during the heating operation.

14 and 15, the refrigerant circuit configuration and the flow (operation) of the refrigerant in the refrigerating air conditioner are basically the same as those described in the first, fifth and sixth embodiments. Therefore, the same components are denoted by the same reference numerals and description thereof will be omitted.

In the seventh embodiment, in the main heat source unit 1a, the first main service port 16a is provided between the main four-way switching valve 3a and the use side heat exchanger 21, and the main heat exchanger 4a and the use side heat The second main service port 1 with the exchange 21
7a, and a third main service port 18a at the bottom of the main liquid reservoir 5a.
b and a use side heat exchanger 21, a first sub service port 16 b is provided between the sub heat exchanger 4 b and the use side heat exchanger 21.
And a second sub service port 18b at the bottom of the sub liquid reservoir 5b.
b is different from the configuration of the sixth embodiment.

In the seventh embodiment, when performing a heavy service such as removing the refrigerant from the refrigerant circuit and repairing the refrigerant circuit, when the heat source units (1a, 1b) are repaired,
Since it is only necessary to recover the refrigerant from the heat source device, the recovered refrigerant only needs to be moved to a device other than the heat source device without changing the composition.

In the seventh embodiment, as a first recovery method, for example, a case in which a refrigerant is recovered from the main heat source unit 1a will be described. The same applies to the case where the refrigerant is recovered from the subordinate heat source device 1b. First, as the operation in which the circulation composition does not change, for example, the main heat source unit 1a side stops the operation, and the sub heat source side 1b performs a cooling operation (operation in which the excess refrigerant is less likely to change in composition) (see FIG. 14). 1
The main operation valve 12a and the second main operation valve 13a are closed. Next, the third service port 18a and the first slave service port 16b are connected by a connection tube 19 such as a tube for pressure resistance or a copper pipe.

In this state, the refrigerant in the main heat source unit 1a on the recovery side flows from the third main service port 18a at the bottom of the liquid reservoir 5a through the connecting pipe 15 as shown by the solid arrow in FIG. It is sucked into the first sub service port 16b, which is a low pressure line of the circuit, and can be almost entirely recovered in the sub heat source unit 1b, the liquid line, or the utilization heat exchanger 21. After completion of the recovery, the connecting pipe 19 connecting the third main service port 18a and the first sub service port 16b is removed, and the main heat source unit 1a is repaired. During restoration, main heat source unit 1a
If the first main control valve 12a and the second main control valve 13a on the side are closed as they are, the continuous operation can be performed in an emergency only by the sub heat source unit 1b. Finally, after the restoration of the main heat source unit 1a is completed and the evacuation is completed, the first main operation valve 12a and the second main operation valve 13a are opened.

Next, a description will be given of a second refrigerant recovery method by a heating operation in which the circulation composition is likely to change due to the generation of surplus refrigerant (see FIG. 15). First, the main heat source 1a stops operating, the sub heat source 1b performs heating operation, and closes the first main operation valve 12a and the second main operation valve 13a. Next, the third service port 18a and the second slave service port 17b are connected by a connection tube 15 such as a tube for pressure resistance or a copper pipe.

In this state, the refrigerant in the main heat source unit 1a on the recovery side flows from the third service port 18a at the bottom of the liquid reservoir 5a through the connecting pipe 15 to the refrigerant circuit as shown by the dotted arrow in FIG. Second service port 1 which is a low pressure line of
7b, and almost all can be collected in the subordinate heat source unit 1b, the liquid line, or the utilization heat exchanger 21. After the collection is completed, the connecting pipe 19 connecting the third service port 18a and the second slave service port 17b is removed, and the main heat source unit 1a is repaired. During the restoration, if the first main operation valve 12a and the second main operation valve 13a on the main heat source unit 1a side are closed as they are, the continuous operation can be performed with only the sub heat source unit 1b. Finally, the repair of the main heat source unit 1a is completed,
After the evacuation is completed, the first main operation valve 12a and the second
The main operation valve 13a is opened.

As described above, in the refrigerant circuit of the refrigeration / air-conditioning apparatus according to the seventh embodiment, almost all of the refrigerant can be removed by the first and second recovery methods without changing the refrigerant composition in the heat source unit. Liquid line, use heat exchanger 21,
Or it can be collected in a gas line. After the restoration of each heat source unit is completed and the evacuation is completed, the first main operation valve 12a, the second main operation valve 13a, and the first slave operation valve 1
By opening 2b and the second slave valve 13a,
The refrigerant can be recharged, and the recycling rate of the refrigerant increases.

Thus, even when the refrigerant is removed from the refrigerant circuit and the refrigerant circuit is repaired, a new refrigerant is not required after the repair, so that the cost can be reduced and the refrigerant can be easily recharged. Thus, a refrigeration / air-conditioning apparatus that can shorten service time and can perform emergency operation during service can be obtained.
Further, since the collected refrigerant is not discarded, that is, reused, environmental problems such as global warming can be solved.

In the seventh embodiment, the composition detector 6
Even in a refrigerant circuit having no refrigerant, it is possible to recover the refrigerant without changing the refrigerant composition and to reuse the recovered refrigerant. Further, in a refrigerant circuit configured by a single heat source device instead of a plurality of heat source devices (corresponding to 1a and 1b in the present embodiment) or a refrigerant circuit having the configuration of the second, third, and fourth embodiments. Also, by providing the same configuration as in the sixth embodiment, the same effect can be obtained.

[0116]

As described above, according to the present invention, the provision of the circulating composition detecting device makes it possible to always detect the true refrigerant circulating composition. Thereby, for example, refrigerant stagnation in the indoor unit at the time of heating, or excess refrigerant stagnation in each heat source unit causes uneven distribution of the refrigerant,
Even if the composition of the refrigerant circulating in the refrigerant circuit changes,
Alternatively, even when the composition of the refrigerant changes due to factors such as refrigerant leakage and refrigerant mis-filling, the change can be detected and the composition can be corrected.

According to the next invention, since each heat source unit is provided with a flow control valve, the circulation amount of the refrigerant flowing through each heat source unit can be adjusted. Thereby, there is an effect that the uneven distribution of the surplus refrigerant can be eliminated.

According to the next invention, when the superheat degree of the slave heat source unit is larger than that of the main heat source unit, the difference of the superheat degree of each heat source unit is set smaller than the preset value. Close the valve and open the slave flow control valve. On the other hand, when the degree of superheat on the slave heat source unit side is smaller than that on the main heat source unit side, the main flow control valve is opened until the difference in the degree of superheat between the respective heat source units becomes smaller than a preset value. Close the flow control valve. Thereby, there is an effect that the uneven distribution of the surplus refrigerant can be automatically eliminated.

According to the next invention, the two degrees of superheat SH
Even if a and SHb are smaller than a predetermined value A set in advance, the degree of superheat (S
H) is ensured, and the excess refrigerant is not retained in the main liquid reservoir and the sub liquid reservoir. As a result, there is an effect that the composition fluctuation of the circulating refrigerant can be suppressed and the proper operation can always be performed.

According to the next invention, it is possible to recover the refrigerant without changing the refrigerant composition and to reuse the recovered refrigerant. Accordingly, even in the case where the refrigerant is removed from the refrigerant circuit and the refrigerant circuit is repaired, a new refrigerant is not required after the repair, so that there is an effect that the cost can be reduced.

According to the next invention, almost all of the refrigerant can be recovered to the liquid line, the indoor heat exchanger, or the gas line without changing the refrigerant composition in the heat source device. After the restoration of each heat source unit is completed and the evacuation is completed, the first operation valve and the second operation valve are opened,
The refrigerant can be recharged, and the refrigerant recycling rate increases. As a result, even when the refrigerant is removed from the refrigerant circuit and the refrigerant circuit is repaired, a new refrigerant is not required after the repair, so that the cost can be reduced and the refrigerant can be easily recharged. This has the effect of shortening the service time.

According to the next invention, almost all of the refrigerant can be recovered to the liquid line, the indoor heat exchanger, or the gas line without changing the refrigerant composition in the heat source unit. Can be continued without stopping.
In addition, after the repair of each heat source unit is completed and the evacuation is completed,
By opening the first operation valve and the second operation valve, the refrigerant can be recharged, and the refrigerant recycling rate also increases.
As a result, even when the refrigerant is removed from the refrigerant circuit and the refrigerant circuit is repaired, a new refrigerant is not required after the repair, so that the cost can be reduced and the refrigerant can be easily recharged. In addition, the service time can be shortened, and an emergency operation (continuous operation) at the time of service can be performed.

Therefore, according to the present invention, the reliability is improved by correcting the composition change of the non-azeotropic refrigerant mixture, and the cost is reduced by enabling the recovered refrigerant to be reused. Refrigeration and air-conditioning system can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of a refrigerant circuit diagram of a refrigeration / air-conditioning apparatus according to the present invention.

FIG. 2 is a configuration of a composition detection unit.

FIG. 3 is a Mollier diagram in a composition detection unit.

FIG. 4 is an application example of the first embodiment.

FIG. 5 is a diagram showing Embodiment 2 of the refrigerant circuit diagram of the refrigeration / air-conditioning apparatus according to the present invention.

FIG. 6 is an application example of the second embodiment.

FIG. 7 is a diagram showing Embodiment 3 of a refrigerant circuit diagram of a refrigeration / air-conditioning apparatus according to the present invention.

FIG. 8 is a block diagram of a leveling control.

FIG. 9 shows the compressor refrigerant circulation amount, pressure loss, evaporation temperature,
It is a relation figure with a heat exchanger superheat degree or a liquid amount in a liquid reservoir.

FIG. 10 is a diagram showing Embodiment 4 of a refrigerant circuit diagram of a refrigeration / air-conditioning apparatus according to the present invention.

FIG. 11 is a block diagram of a leveling control.

FIG. 12 is a diagram showing Embodiment 5 of a refrigerant circuit diagram of a refrigeration / air-conditioning apparatus according to the present invention.

FIG. 13 is a diagram showing Embodiment 6 of a refrigerant circuit diagram of a refrigeration / air-conditioning apparatus according to the present invention.

FIG. 14 is a diagram showing a refrigerant circuit diagram of a refrigeration / air-conditioning apparatus according to Embodiment 7 of the present invention (refrigerant flow during cooling operation).

FIG. 15 is a diagram showing a refrigerant circuit diagram of a refrigeration / air-conditioning apparatus according to Embodiment 7 of the present invention (flow of refrigerant during heating operation).

FIG. 16 is a refrigerant circuit diagram of a conventional refrigeration / air-conditioning apparatus.

[Explanation of symbols]

1a, 101a Main heat source unit, 1b, 101b Secondary heat source unit, 2a, 102a Main compressor, 2b, 102b Secondary compressor, 3a, 103a Main four-way switching valve, 3b, 103b
Slave four-way switching valve, 4a, 104a main heat exchanger, 4b,
104b Secondary heat exchanger, 5a, 105a Main liquid reservoir, 5
b, 105b Secondary liquid reservoir, 6, 6a, 6b composition detector,
7, 7a main low pressure detecting section, 7b sub low pressure detecting section, 8a main flow control valve, 8b sub flow control valve, 9a main temperature detecting section, 9b sub temperature detecting section, 10a superheat degree calculating device for main heat exchanger, 10b slave heat exchanger superheat degree calculating device,
11a second main reservoir, 11b second slave reservoir, 1
2a first main operating valve, 12b first slave operating valve, 13
a second main operating valve, 13b second sub operating valve, 14
Refrigerant recovery port, 15 flow control valve controller, 16a first main service port, 16b first sub service port,
17a second main service port, 17b second sub service port, 18a third main service port, 18b
Third slave service port, 19 connecting pipe, 21, 12
1 use side heat exchanger, 22, 122 use side flow control device, 31, 131 liquid junction, 32, 132 gas junction, 41 composition detection heat exchanger, 42 decompression section, 43
A first temperature detector, 44 a second temperature detector;

Claims (7)

[Claims] 1. A refrigeration and air-conditioning system comprising a large-capacity heat source unit comprising a plurality of heat source units and circulating a non-azeotropic mixed refrigerant as a refrigerant, wherein at least one main compressor, main four-way switching valve, main heat A main heat source unit having an exchanger and a first main reservoir; and at least one having at least one sub compressor, a sub four-way switching valve, a sub heat exchanger, and a first sub main reservoir. A liquid joining section that joins two auxiliary heat source units, a pipe serving as a passage for the liquid refrigerant flowing out of the main heat exchanger, and a pipe serving as a passage for the liquid refrigerant flowing out of the slave heat exchanger; and A gas merging section for joining a pipe serving as a passage for gas refrigerant discharged from the compressor, a pipe serving as a passage for gas refrigerant discharged from the slave compressor, and a circulation for detecting a circulating composition of the non-azeotropic mixed refrigerant A composition detection device, and a refrigerant circuit comprising: The inflow of the refrigerant circulating through the serial refrigerant circuit, the refrigeration air conditioning system which is characterized in that the cooling operation or heating operation at the use-side heat exchanger. 2. The refrigeration system according to claim 1, further comprising a flow control valve for adjusting a flow rate of the refrigerant between the heat exchanger of at least one heat source unit and the liquid junction. Air conditioner. 3. Each of the heat source devices comprises: a low-pressure pressure detecting means for detecting a pressure of the refrigerant; and a temperature detecting means for detecting a temperature of the refrigerant, wherein the flow rate control is performed based on the detected pressure and temperature. The refrigeration / air-conditioning apparatus according to claim 2, wherein the valve is adjusted to prevent the excess refrigerant remaining in each heat source unit from being unevenly distributed. 4. At least one second liquid reservoir is provided between a heat exchanger in each heat source unit and the use side heat exchanger, and each heat source is adjusted by adjusting the flow control valve. 3. A method according to claim 2, wherein a predetermined amount of surplus refrigerant staying in the machine is secured in the second liquid reservoir while the refrigerant is always kept in a fluidized state, and the surplus refrigerant remaining in the first liquid reservoir is suppressed. Or the refrigeration / air-conditioning apparatus according to 3. 5. A refrigerant recovery port is provided in a pipe between the heat exchanger and the use side heat exchanger, and for controlling a refrigerant from the use side heat exchanger for each heat source unit. And a second operating valve for controlling the refrigerant from the heat exchanger in the heat source unit, wherein the refrigerant is supplied to the refrigerant circuit without changing the composition of the non-azeotropic mixed refrigerant. The refrigeration air conditioner according to any one of claims 1 to 4, wherein the refrigerant is collected outside the system, and then the collected refrigerant is reused. 6. A flow control means for controlling a flow rate of a refrigerant flowing into the use side heat exchanger, wherein the refrigerant is recovered outside the heat source device without changing the composition of the non-azeotropic mixed refrigerant, and The refrigeration / air-conditioning apparatus according to claim 5, wherein the collected refrigerant is reused. 7. Each heat source unit is provided with a service port for moving the refrigerant to another heat source unit, and the refrigerant is recovered to another heat source unit without changing the composition of the non-azeotropic mixed refrigerant. 7. The refrigeration / air-conditioning apparatus according to claim 5, wherein the collected refrigerant is reused thereafter.