JPH10253203A - Refrigerant recovering method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerant recovering method in which an amount of refrigerant can be adjusted without causing any variation in composition of non-azeotropic mixture refrigerant charged in a freezer device and then a normal operation of the freezer device can be easily carried out after adjustment. SOLUTION: This refrigerant recovering method is carried out such that a first flow rate adjusting valve 11 is connected to a refrigerant circuit of a freezer device 1 using non-azeotropic mixture refrigerant through a first refrigerant recovering port 9, refrigerant containing a large amount of refrigerant of low boiling point is recovered, a second flow rate adjusting valve 12 is connected to the refrigerant circuit through a second refrigerant recovering port 10 so as to recover refrigerant containing a large amount of refrigerant of high boiling point. With such an arrangement as above, it is possible to recover refrigerant containing a large amount of refrigerant of lower boiling point than that of composition of the mixed non-azeotropic mixture refrigerant in compliance with recovering of refrigerant containing a large amount of refrigerant of higher boiling point than that of composition of the non-azeotropic mixture refrigerant. Due to this fact, the composition of the non-azeotropic mixture refrigerant is not changed through recovering of the refrigerant, occurrence of abnormal state of operating pressure of the freezing device can be prevented and the freezing device can be operated normally in an easy manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant recovery method in a refrigeration system using a non-azeotropic mixed refrigerant.

[0002]

2. Description of the Related Art FIG.
8 is a diagram illustrating a conventional refrigerant recovery method disclosed in Japanese Patent Publication No. 8 and is a refrigerant circuit diagram of a refrigeration apparatus. In the figure, reference numeral 1 denotes a refrigerating device, which includes a compressor 2, a condenser 3, an expansion device 4, and an evaporator 5.
And a refrigerant circuit in which the accumulator 6 is sequentially connected. Reference numeral 7 denotes a refrigerant recovery tank connected to the accumulator 6 via a communication on-off valve 8.

In the conventional refrigerant recovery method, the following operation is performed by the above-described apparatus configuration. That is,
When the refrigerant is collected in order to adjust the refrigerant amount to an appropriate amount when the refrigerant is overfilled, the liquid refrigerant in the accumulator 6 is collected in the refrigerant collection tank 7 via the operation of the communication opening / closing valve 8. .

[0004]

In the above-mentioned conventional refrigerant recovery method, when a non-azeotropic refrigerant mixture is used in the refrigeration system 1, the following situation occurs. That is, when the refrigerant is recovered and the refrigerant is recovered in the operation state in which the liquid refrigerant is present in the accumulator 6, the composition of the refrigerant circulating through the refrigeration system 1 is lower in boiling point than the composition of the charged mixed refrigerant. Is obtained. Further, the composition of the refrigerant present as a liquid refrigerant in the accumulator 6 is a composition containing more high-boiling-point refrigerant than the composition of the charged mixed refrigerant.

For this reason, when the refrigerant is recovered by the apparatus configuration shown in FIG. 10, when only the liquid refrigerant of the accumulator 6 is recovered, a refrigerant having a composition containing a higher boiling point refrigerant than the charged mixed refrigerant has a higher composition. Collected. Therefore, the composition of the refrigerant remaining in the refrigeration apparatus 1 is a refrigerant having a composition containing a larger amount of low-boiling refrigerant than the composition of the mixed refrigerant charged. When the refrigeration apparatus 1 is operated with a refrigerant having a composition containing a lower boiling point refrigerant than the composition of the charged mixed refrigerant, the operating pressure becomes higher than the design value.

For this reason, there have been problems that the refrigerant leaks from the refrigeration system 1 and the refrigeration system 1 is damaged. Further, since the liquid refrigerant of the accumulator 6 is recovered, the refrigerating machine oil dissolved in the liquid refrigerant together with the liquid refrigerant is also recovered. As a result, the amount of refrigerating machine oil remaining in the refrigerating apparatus 1 is reduced, so that there is a problem that operation of the refrigerating apparatus 1 is hindered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and provides a refrigerant recovery method capable of adjusting the amount of refrigerant without changing the composition of the non-azeotropic mixed refrigerant and allowing the refrigeration apparatus to operate normally after the adjustment. The purpose is to:

[0008]

In a refrigerant recovery method according to the present invention, a compressor, a condenser, an expansion device, an evaporator, and an accumulator are sequentially connected to each other. The first flow rate control valve connected to the first refrigerant recovery port provided in the refrigerant circuit of the refrigeration apparatus recovers the refrigerant containing a low boiling point refrigerant more than the composition of the mixed refrigerant filled in the refrigeration apparatus, and the refrigerant A second flow rate control valve connected to a second refrigerant recovery port provided in the circuit recovers a refrigerant containing a higher boiling point refrigerant than the mixed refrigerant filled in the refrigeration system.

Further, in the refrigerant recovery method according to the present invention, the first refrigerant recovery port is provided at a location corresponding to the gas refrigerant of the accumulator, so that a refrigerant having a low boiling point is contained more than the composition of the mixed refrigerant charged in the refrigeration system. The recovered refrigerant is recovered.

[0010] In the refrigerant recovery method according to the present invention, the first refrigerant recovery port is provided at a location corresponding to the gas refrigerant in the refrigerant circuit at the outlet of the compressor, and has a boiling point lower than the composition of the mixed refrigerant charged in the refrigeration system. The refrigerant containing a large amount of the refrigerant is recovered.

Further, in the refrigerant recovery method according to the present invention, the first refrigerant recovery port is provided at a position corresponding to the liquid refrigerant in the refrigerant circuit at the outlet of the condenser, and has a boiling point lower than the composition of the mixed refrigerant charged in the refrigeration system. The refrigerant containing a large amount of the refrigerant is recovered.

Further, in the refrigerant recovery method according to the present invention, the second refrigerant recovery port is provided at a location corresponding to the liquid refrigerant of the accumulator, so that the refrigerant having a higher boiling point than the composition of the mixed refrigerant charged into the refrigeration system is contained. The recovered refrigerant is recovered.

Further, in the refrigerant recovery method according to the present invention, the refrigerant recovery amount from the first refrigerant recovery port and the refrigerant recovery amount from the second refrigerant recovery port are recovered at a predetermined ratio.

Further, in the refrigerant recovery method according to the present invention, the amount of refrigerant recovered from the first refrigerant recovery port and the amount of refrigerant recovered from the second refrigerant recovery port are determined by the circulation composition of the refrigerant in the refrigeration system by the circulation composition detecting device. Is determined.

Further, in the refrigerant recovery method according to the present invention, the refrigerant recovery amount from the first refrigerant recovery port and the second refrigerant recovery amount are calculated based on the circulating composition estimated from the total refrigerant amount charged and the surplus refrigerant ratio based on the surplus refrigerant amount of the accumulator. The ratio with respect to the refrigerant recovery amount from the refrigerant recovery port is determined.

Further, in the refrigerant recovery method according to the present invention, the composition of the refrigerant recovered from the first refrigerant recovery port is detected by the detecting means, and based on the result, the refrigerant recovery amount from the first refrigerant recovery port and the second refrigerant recovery amount are detected. The ratio with the refrigerant recovery amount from the two refrigerant recovery ports is determined.

Further, in the refrigerant recovery method according to the present invention, the composition of the refrigerant recovered from the second refrigerant recovery port is detected by the detecting means, and based on the result, the amount of the refrigerant recovered from the first refrigerant recovery port is determined. The ratio with the refrigerant recovery amount from the two refrigerant recovery ports is determined.

Further, in the refrigerant recovery method according to the present invention, the refrigerant recovered from the second refrigerant recovery port is processed by the oil separation device, and only the refrigerant after oil separation of the refrigerator is recovered.

Further, in the refrigerant recovery method according to the present invention, the refrigerating machine oil amount corresponding to the refrigerating machine oil amount in the refrigerant recovered from the second refrigerant recovery port is replenished from the refrigerating machine oil supply container.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a diagram showing an example of an embodiment of the present invention, which is a refrigerant circuit of a refrigeration apparatus. In the figure, 1
Is a refrigerating device, which constitutes a refrigerant circuit in which the compressor 2, the condenser 3, the expansion device 4, the evaporator 5, and the accumulator 6 are sequentially connected. Reference numeral 9 denotes a first refrigerant recovery port provided on the upper side of the accumulator 6, and reference numeral 10 denotes a second refrigerant recovery port provided on the lower side of the accumulator 6.

11 is a first flow control valve connected to the first refrigerant recovery port 9, 12 is a second flow control valve connected to the second refrigerant recovery port 11, and 7 is the first flow control valve 11 and the second flow control valve. It is a refrigerant recovery tank to which the flow control valves 12 are connected respectively. Reference numeral 13 denotes a refrigerant recovery device, which includes the first flow control valve 11, the second flow control valve 12, and the refrigerant recovery tank 7. The refrigeration system 1 has R32 / R125 / R134.
a is mixed at a ratio of 23/25/52 wt% to form R407C which forms a non-azeotropic mixed refrigerant.

In the refrigeration apparatus 1 configured as described above, the high-temperature, high-pressure gas refrigerant discharged from the compressor 2 flows into the condenser 3, and is cooled by room temperature air or the like to condense into a liquid refrigerant. . Then, the liquid refrigerant flowing out of the condenser 3 is decompressed by the expansion device 4, flows into the evaporator 5, generates a low temperature, evaporates and gasifies. Next, the gas refrigerant flows into the accumulator 6, passes through the accumulator 6, and is sucked into the compressor 2. In such a refrigeration cycle, the surplus refrigerant in the refrigeration apparatus 1 exists in the accumulator 6 in the form of a liquid refrigerant.

The refrigerant in the refrigeration system 1 has the following composition. That is, the composition of the refrigerant circulating in the refrigerating apparatus 1 including the composition of the gas refrigerant in the accumulator 6 is the same as the refrigerant circulating in the refrigerating apparatus 1. Therefore, the gas composition in the accumulator 6,
The gas refrigerant discharged from the compressor 2 and the liquid refrigerant at the outlet of the condenser 3 have the same composition. In addition, a gas-liquid equilibrium relationship is established in the accumulator 6 between the gas refrigerant and the liquid refrigerant in the accumulator 6.

When the gas-liquid equilibrium relationship is established in the non-azeotropic mixed refrigerant, the gas becomes a refrigerant containing more low-boiling components than the liquid, and the liquid becomes a refrigerant containing more high-boiling components than the gas. Therefore, the gas refrigerant in the accumulator 6 becomes a refrigerant containing more refrigerants R32 and R125 having a lower boiling point than the liquid refrigerant. Further, the liquid refrigerant in the accumulator 6 is a refrigerant containing more refrigerant R134a having a higher boiling point than the gas refrigerant.

All the refrigerant in the refrigeration system 1 becomes a refrigerant obtained by combining the refrigerant circulating in the refrigeration system 1 and the liquid refrigerant in the accumulator 6, and the composition of the combined refrigerant becomes the same as the filled refrigerant R407C. . Therefore, the composition of the refrigerant circulating in the refrigerating apparatus 1 including the composition of the gas refrigerant in the accumulator 6 is a refrigerant containing more refrigerants R32 and R125 having a lower boiling point than the composition of the filled refrigerant R407C. In addition, the composition of the liquid refrigerant in the accumulator 6 is a refrigerant containing more refrigerant R134a having a higher boiling point than the composition of the filled refrigerant R407C.

Therefore, by recovering the liquid refrigerant in the accumulator 6, it is possible to recover a refrigerant containing a higher boiling point refrigerant than the composition of the charged mixed refrigerant. Also, by collecting the gas refrigerant in the accumulator 6 in conjunction with the recovery of the refrigerant containing a large amount of the high-boiling refrigerant, it is possible to recover the refrigerant containing a large amount of the low-boiling refrigerant than the composition of the mixed refrigerant mixture. it can.

Then, refrigerant adjustment of the refrigeration system 1 is performed as described below. That is, for example, when the installation and piping are performed at the installation site due to the reason that the refrigeration apparatus 1 is large, the refrigeration apparatus 1 is shipped from the factory without being filled with the mixed refrigerant. Then, at the stage where the installation and piping are completed on site, the mixed refrigerant is charged. The amount of the refrigerant to be charged at this time is set at the time of designing the refrigeration apparatus 1 according to installation conditions such as the length of a connected pipe.

However, if the operating conditions assumed at the time of designing the refrigeration system 1 are different from the actual operating conditions, or if the amount of the refrigerant to be charged is incorrect, the refrigeration system 1 needs a larger amount of refrigerant than the appropriate amount. May be filled. In such a state, whether or not the mixed refrigerant is charged in an appropriate amount is verified by trial operation of the refrigeration apparatus 1.

That is, when the refrigeration apparatus 1 is in the operation state assumed at the time of the test operation when the refrigeration apparatus 1 is designed, it is clear that the proper refrigerant amount is charged. However, if the operation state is different from the operation state assumed at the time of design, there is an excess or deficiency in the charged amount of the refrigerant. When the refrigeration apparatus 1 is operated in an excessive refrigerant state, the high pressure of the refrigeration apparatus 1 is higher than the operation state assumed at the time of design, the degree of supercooling at the outlet of the condenser 3 is large, or the surplus exists in the accumulator 6. Is large.

If the operation is continued under such a condition, the high pressure may be excessively increased depending on the operation condition, and the refrigeration system 1 may be damaged. In addition, the liquid refrigerant overflows into the accumulator 6, and the liquid refrigerant is sucked into the compressor 2, and the compressor 2 may be damaged. For this reason, it becomes necessary to recover the excess refrigerant from the refrigeration apparatus 1 and adjust the liquid refrigerant.

The collection of the refrigerant and the adjustment of the refrigerant are performed while the refrigeration system 1 is operating. That is, the method is performed by collecting a small amount of the refrigerant, observing the operation state in that state, and determining whether the refrigerant needs to be collected. Then, if the operating state assumed at the time of design after the recovery is performed, the refrigerant recovery is thereby terminated.

However, it is said that the high pressure of the refrigeration system 1, the supercooling degree at the outlet of the condenser 3 is large, or the amount of the excess liquid refrigerant existing in the accumulator 6 is larger than the operation state assumed at the time of design after the recovery. Refrigeration unit 1
The refrigerant inside will be excessive. Therefore, the refrigerant recovery is performed again.

It is also possible to stop the operation of the refrigeration system 1 and recover the refrigerant. However, it is necessary to restart the operation to determine whether the refrigerant amount is appropriate,
The operation time of the refrigerant amount adjustment becomes longer. Therefore, it is not suitable as a technique for adjusting the amount of refrigerant.

When only the liquid refrigerant of the accumulator 6 is recovered at the time of recovering the refrigerant, the liquid refrigerant of the accumulator 6 becomes R
Since the refrigerant has a composition containing a higher boiling point refrigerant R134a than the composition of 407C, the refrigerant remaining in the refrigeration apparatus 1 has a composition containing less high boiling point refrigerant R134a than the composition of R407C. When only the gas refrigerant of the accumulator 6 is collected at the time of refrigerant recovery, the gas refrigerant of the accumulator 6 has a lower boiling point refrigerant R than the composition of R407C.
Since the refrigerant has a composition containing a large amount of R32 and R125, the refrigerant remaining in the refrigeration apparatus 1 has a composition containing less low-boiling-point refrigerants R32 and R125 than the composition of R407C.

When such refrigerant recovery is performed, refrigerant having a mixed composition different from that of the mixed refrigerant set at the time of design remains in the refrigeration system 1. For this reason, the high pressure of the refrigeration system 1 becomes higher than the value set at the time of design, and the refrigeration system 1 may be damaged or the capacity of the refrigeration system 1 may be insufficient.

In response to such a situation, the liquid refrigerant of the accumulator 6 and the gas refrigerant of the accumulator 6 are recovered together so that the composition of the mixed refrigerant remaining in the refrigeration system 1 does not change from the initial composition of the refrigerant R407C. I do. When the operation state of the refrigeration system 1 can be predicted and the amount of refrigerant required for the refrigeration system 1 becomes constant, and the amount of refrigerant to be charged and the amount of overfilled refrigerant do not differ greatly, the composition of the refrigerant is predicted. can do.

Therefore, it is possible to determine the ratio of the recovery amount of the liquid refrigerant of the accumulator 6 and the recovery amount of the gas refrigerant of the accumulator 6 when recovering the refrigerant. For example, when the refrigerant is charged, the liquid refrigerant amount of the accumulator 6 becomes 60% of the total refrigerant amount of the refrigeration apparatus 1, and when the amount of overfilled refrigerant is not so large, the composition of the gas refrigerant in the accumulator 6 is included. The composition of the mixed refrigerant circulating in the refrigeration system 1 is R32 / R
125 / R134a = 30/30/40 wt%.
The composition of the liquid refrigerant in the accumulator 6 is R32 / R
125 / R134a = 18/21/61 wt%.

Then, the gas refrigerant in the accumulator 6 is reduced by 40% as the ratio of the amount of gas and liquid collected in the accumulator 6.
% And liquid refrigerant of 60%, the following results can be obtained. That is, R32 is equal to the composition of the refrigerant R407C filled by the structure of the refrigerant to be recovered.
/ R125 / R134a = 23/25/52 wt%.

In this way, the refrigerant containing the refrigerant having a higher boiling point than the charged refrigerant is recovered, and the refrigerant containing the refrigerant having a lower boiling point than the charged refrigerant is recovered. In addition, a refrigerant containing a higher boiling point refrigerant than the filled refrigerant and a refrigerant containing a lower boiling point refrigerant than the charged refrigerant are recovered at a predetermined ratio.

As a result, the composition of the mixed refrigerant remaining in the refrigeration apparatus 1 does not change due to refrigerant recovery. Therefore, the amount of the refrigerant can be adjusted without changing the composition of the mixed refrigerant, that is, the non-azeotropic mixed refrigerant, and problems such as leakage of the refrigerant from the refrigeration apparatus 1 and damage to the refrigeration apparatus 1 can be solved. . Then, the refrigeration apparatus can be easily operated without any abnormality after the adjustment of the refrigerant amount.

In the refrigerant recovery operation, the refrigerant recovery tank 7 is evacuated, and then the openings of the first flow control valve 11 and the second flow control valve 12 are respectively adjusted so that the flow rates of the liquid and gas refrigerant are 6: Set to 4 Refrigerant is recovered from the first flow control valve 11 and the second flow control valve 12 at the same time. By doing so, the refrigerant can be recovered so that the liquid refrigerant in the accumulator 6 has a ratio of 60% and the gas refrigerant has a ratio of 40%.

The operation of recovering the refrigerant is performed by the first flow control valve 1.
The opening degrees of the first and second flow control valves 12 are respectively adjusted to set the same refrigerant and gas refrigerant flow rates. Then, the ratio of the time for recovering the liquid refrigerant and the time for recovering the gas refrigerant for the first flow control valve 11 and the second flow control valve 12 is set to 6: 4. Also in this case, the refrigerant can be recovered at a rate of 60% of the liquid refrigerant and 40% of the gas refrigerant of the accumulator 6.

Further, as another method, instead of the first flow control valve 11 and the second flow control valve 12, a fixed opening degree whose opening degree is known and whose flow rate when a liquid or gas refrigerant flows can be predicted. The on-off valve of is provided. The liquid refrigerant in the accumulator 6 can be reduced by 60% by adjusting the opening time of the on-off valve so that the liquid and gas refrigerant amounts to be recovered are 6: 4.
The refrigerant can be recovered at a rate of 40% of the gas refrigerant.

Although the above refrigerant recovery method has been described for the case where R407C is used as the mixed refrigerant, the refrigerant recovery is similarly performed even when another non-azeotropic mixed refrigerant is used. Thus, the same operation as described above can be obtained. It is also possible to provide two refrigerant recovery tanks 7 so as to collect the refrigerant containing a high boiling point refrigerant in one, and to collect the refrigerant containing a large amount of the low boiling point refrigerant in the other.

Embodiment 2 FIG. 2 shows an example of another embodiment of the present invention, which is a refrigerant circuit of a refrigeration apparatus. In the drawing, the same reference numerals as those in FIG. 1 described above denote corresponding parts, and reference numeral 14 denotes a first refrigerant recovery port disposed between the compressor 2 and the condenser 3 for recovering the gas refrigerant discharged from the compressor 2. . In addition, the gas refrigerant discharged from the compressor 2 is a refrigerant containing a low-boiling-point refrigerant more than the composition of the mixed refrigerant charged in the refrigeration apparatus 1.

Also in the refrigeration system 1 configured as described above, by collecting the gas refrigerant passing through the first refrigerant recovery port 14, the refrigerant containing a low boiling point refrigerant more than the composition of the charged mixed refrigerant is recovered. . Then, by collecting the liquid refrigerant in the accumulator 6 in conjunction with this collection, it is possible to collect a refrigerant containing a higher boiling point refrigerant than the composition of the charged mixed refrigerant. Therefore, although detailed description is omitted, the same operation as the embodiment of FIG. 1 can be obtained in the embodiment of FIG.

Embodiment 3 FIG. 3 also shows an example of another embodiment of the present invention, which is a refrigerant circuit of a refrigeration apparatus. In the figure, the same reference numerals as those in FIG. 1 described above denote corresponding parts, and reference numeral 15 denotes a first medium recovery port disposed between the condenser 3 and the expansion device 4 for recovering the liquid refrigerant after the outlet of the condenser 3.
The liquid refrigerant after the outlet of the condenser 3 is a refrigerant containing a lower boiling point refrigerant more than the composition of the mixed refrigerant charged in the refrigeration apparatus 1.

Also in the refrigeration system 1 configured as described above, by collecting the liquid refrigerant through the first medium recovery port 15, the refrigerant containing a low boiling point refrigerant more than the composition of the charged mixed refrigerant is recovered. . Then, by collecting the liquid refrigerant in the accumulator 6 in conjunction with this collection, it is possible to collect a refrigerant containing a higher boiling point refrigerant than the composition of the charged mixed refrigerant. Therefore, although detailed description is omitted, the same operation as the embodiment of FIG. 1 can be obtained in the embodiment of FIG.

Embodiment 4 FIGS. 4 and 5 also show an example of another embodiment of the present invention, and FIG. 5 is a graph showing the relationship between the excess refrigerant ratio and the circulation composition in the refrigeration apparatus of FIG. . In the figure, FIG.
The same reference numerals denote corresponding parts, and 16 is a circulating composition detecting device, which is a bypass pipe 17, a double heat exchanger 18, and a decompression device 1.
9, temperature detector 20, pressure detector 21, and composition calculator 2
2.

Also in the refrigeration apparatus 1 configured as described above, by recovering the liquid refrigerant in the accumulator 6, it is possible to recover a refrigerant containing a higher boiling point refrigerant than the composition of the charged mixed refrigerant. By collecting the gas refrigerant in the accumulator 6, it is possible to recover a refrigerant containing a low-boiling refrigerant more than the composition of the charged mixed refrigerant. Therefore, although detailed description is omitted, the same operation as the embodiment of FIG. 1 can be obtained in the embodiments of FIGS.

In the embodiment shown in FIGS. 4 and 5, the high-pressure gas refrigerant leaving the compressor 2 passes through the bypass pipe 17 and exchanges heat with the low-pressure refrigerant in the double heat exchanger 18 to be liquefied. You. Next, the pressure is reduced by the pressure reducing device 19 to become a low-pressure two-phase refrigerant, and then the heat is exchanged with the high-pressure refrigerant by the double heat exchanger 18 to evaporate and gasify, and then returned to the compressor 2 and sucked. Then, in the circulation composition detecting device 16, the temperature of the low-pressure two-phase refrigerant is detected by the temperature detector 20 and the pressure detector 21,
Detect temperature. The composition of the circulating refrigerant is calculated and inspected by the composition calculator 22 based on the detected value.

Then, the operating state of the refrigeration system 1 can be predicted, the amount of refrigerant required for the refrigeration system 1 becomes a constant value, and the amount of refrigerant to be charged and the amount of overfilled refrigerant do not change much. In this case, since the composition of the mixed refrigerant can be predicted, the ratio between the liquid refrigerant of the accumulator 6 and the recovery amount of the gas refrigerant of the accumulator 6 can be determined at the time of refrigerant recovery. However, when the amount of refrigerant to be charged is significantly different from the amount of overfilled refrigerant, the composition of the mixed refrigerant cannot be predicted, so that the liquid refrigerant of the accumulator 6 and the accumulator 6
It is not possible to determine the ratio of the recovery amount of the gas refrigerant.

In such a situation, first, the composition of the circulating refrigerant is checked by the circulation composition detecting device 16. That is, since the circulating composition is the same as the gas composition of the accumulator 6, if the gas composition of the accumulator 6 is known, the liquid composition of the accumulator 6 can be known from the gas-liquid equilibrium relationship in the accumulator 6. Accordingly, when the gas and liquid compositions of the accumulator 6 are determined, the recovered amounts of the liquid refrigerant of the accumulator 6 and the gas refrigerant of the accumulator 6 are determined so that the composition of the mixed refrigerant remaining in the refrigeration apparatus 1 after refrigerant recovery does not change to R407C. The percentage can be determined.

For example, if the circulation composition, that is, the gas composition of the accumulator 6, is R32 / R125 / R134a = 30 /
When 30/40 wt% is detected, the composition of the liquid refrigerant in the accumulator 6 is determined to be R32 / R12
5 / R134a = 18/21/61 wt%. Therefore, when recovering the refrigerant when the mixed refrigerant is overfilled, the ratio of the recovery amount of the gas and liquid refrigerant in the accumulator 6 is set to 40% for the gas refrigerant in the accumulator 6 and 60% for the liquid refrigerant in the accumulator 6. And

As a result, the composition of the refrigerant to be recovered is equal to the composition of the mixed refrigerant R407C charged, and R32 / R12
5 / R134a = 23/25/52 wt%, and the composition of the mixed refrigerant remaining in the refrigeration apparatus 1 does not change due to refrigerant recovery. As described above, the composition of the refrigerant circulating in the refrigeration system 1 by the circulation composition detecting device 16 is verified, that is, the recovered amount of the refrigerant containing a large amount of the high-boiling-point refrigerant and the refrigerant containing the large amount of the low-boiling-point refrigerant due to the circulation composition of the mixed refrigerant Is determined.

As a result, the amount of the refrigerant can be adjusted without fluctuation in the composition of the non-azeotropic mixed refrigerant, and problems such as leakage of the refrigerant from the refrigeration system 1 and damage to the refrigeration system 1 can be solved. Then, the refrigeration apparatus can be easily operated without any abnormality after the adjustment of the refrigerant amount.

Instead of examining the composition of the circulating refrigerant, the circulating composition can also be specified by obtaining information that can specify the circulating composition or the composition of the refrigerant to be recovered from the operating state of the refrigeration system 1. For example, a liquid level detecting mechanism (not shown) may be provided in the accumulator 6 to determine the amount of refrigerant in the accumulator 6. When the amount of the refrigerant in the accumulator 6 is known, the amount of the refrigerant existing in a portion other than the accumulator 6 in the refrigeration apparatus 1 can be estimated based on the operation state. it can.

Thus, it is possible to know the ratio of the surplus refrigerant amount present in the accumulator 6 to the total refrigerant amount charged and the surplus refrigerant ratio. By knowing the surplus refrigerant rate, the circulation composition, that is, the gas refrigerant in the accumulator 6, can be known by obtaining in advance the relationship between the surplus refrigerant rate and the circulation composition that results in the situation shown in FIG. . When the gas refrigerant is determined, the composition of the liquid refrigerant can also be known from the gas-liquid equilibrium relationship, so that the composition of the mixed refrigerant remaining in the refrigeration system 1 is not changed by the refrigerant recovery, and the gas refrigerant in the accumulator 6 and the accumulator 6 are changed. The recovery ratio of the liquid refrigerant in 6 can be determined.

Embodiment 5 FIG. FIG. 6 also shows another example of the embodiment of the present invention, which is a refrigerant circuit of a refrigeration apparatus. The refrigeration system is configured in the same manner as in FIG. 1 except for FIG. In the figure, the same reference numerals as those in FIG. 1 described above denote corresponding parts, and reference numeral 23 denotes a detecting means formed by gas chromatography connected to the first refrigerant recovery port 9.

Also in the refrigeration system 1 configured as described above, by collecting the liquid refrigerant in the accumulator 6, it is possible to recover a refrigerant containing a high boiling point refrigerant more than the composition of the charged mixed refrigerant. Thus, by recovering the gas refrigerant in the accumulator 6, it is possible to recover a refrigerant containing a low boiling point refrigerant more than the composition of the charged mixed refrigerant. Therefore, although the detailed description is omitted, the same operation as the embodiment of FIG. 1 can be obtained in the embodiment of FIG.

In the embodiment shown in FIG. 6, the composition of the gas refrigerant in the accumulator 6 to be recovered is measured by the detecting means 23. From the measurement result, the composition of the liquid refrigerant in the accumulator 6 is determined using the gas-liquid equilibrium relation. You can know. Thereby, the recovery ratio of the gas refrigerant in the accumulator 6 and the liquid refrigerant in the accumulator 6 can be determined so that the composition of the mixed refrigerant remaining in the refrigeration apparatus 1 does not change due to the refrigerant recovery.

As a result, the amount of the refrigerant can be adjusted without fluctuation in the composition of the non-azeotropic mixed refrigerant, and the problems that the refrigerant leaks from the refrigeration system 1 or the refrigeration system 1 is damaged can be solved. Then, the refrigeration apparatus can be easily operated without any abnormality after the adjustment of the refrigerant amount. Note that the measurement of the composition and the recovery of the refrigerant can be performed simultaneously.

Embodiment 6 FIG. FIG. 7 is also a view showing an example of another embodiment of the present invention, which is a refrigerant circuit of a refrigeration apparatus. Note that the refrigeration apparatus is configured in the same manner as in FIG. 1 except for FIG. In the figure, the same reference numerals as those in FIG.
0 and a gas chromatography connected to the second refrigerant recovery port 10.

Also in the refrigeration system 1 configured as described above, by collecting the liquid refrigerant in the accumulator 6, it is possible to collect the refrigerant containing a higher boiling point refrigerant than the composition of the charged mixed refrigerant. Thus, by recovering the gas refrigerant in the accumulator 6, it is possible to recover a refrigerant containing a low boiling point refrigerant more than the composition of the charged mixed refrigerant. Therefore, although detailed description is omitted, the same operation as the embodiment of FIG. 1 can be obtained in the embodiment of FIG.

In the embodiment shown in FIG. 7, the liquid refrigerant of the accumulator 6 recovered from the second refrigerant recovery port 10 is vaporized and gasified by the heater 24, and the composition is measured by the detecting means 23. Thus, the composition of the gas refrigerant in the accumulator 6 can be known using the gas-liquid equilibrium relationship. Thereby, the recovery ratio of the gas refrigerant in the accumulator 6 and the liquid refrigerant in the accumulator 6 can be determined so that the composition of the mixed refrigerant remaining in the refrigeration apparatus 1 does not change due to the refrigerant recovery.

As a result, the amount of the refrigerant can be adjusted without a change in the composition of the non-azeotropic mixed refrigerant, and problems such as leakage of the refrigerant from the refrigeration apparatus 1 and damage to the refrigeration apparatus 1 can be solved. Then, the refrigeration apparatus can be easily operated without any abnormality after the adjustment of the refrigerant amount. Note that the measurement of the composition and the recovery of the refrigerant can be performed simultaneously.

Embodiment 7 FIG. 8 is also a view showing an example of another embodiment of the present invention, which is a refrigerant circuit of a refrigeration apparatus. Note that the refrigeration apparatus is configured in the same manner as in FIG. 1 except for FIG. In the figure, the same reference numerals as those in FIG. 1 described above denote corresponding parts, 25 is an oil separating device, and 26 is a heater provided to face the oil separating device.

In the refrigerating apparatus 1 configured as described above, by collecting the liquid refrigerant in the accumulator 6, it is possible to recover the refrigerant containing a higher boiling point refrigerant than the composition of the charged mixed refrigerant. Thus, by recovering the gas refrigerant in the accumulator 6, it is possible to recover a refrigerant containing a low boiling point refrigerant more than the composition of the charged mixed refrigerant. Therefore, although the detailed description is omitted, the same operation as the embodiment of FIG. 1 can be obtained in the embodiment of FIG.

In the embodiment shown in FIG. 8, the liquid refrigerant of the accumulator 6 in which the refrigerating machine oil is dissolved is supplied to the oil separating device 2.
In 5, heating is performed by the heater 26. As a result, the liquid refrigerant evaporates and is separated into gas refrigerant and refrigerating machine oil, and the separated gas refrigerant flows and is collected in the refrigerant recovery tank 7. Along with the recovery of the gas refrigerant, the refrigerating machine oil is sucked into the pressure machine 2 and refluxed.

As a result, it is possible to prevent the refrigerating machine oil from being collected at the same time as the liquid refrigerant is collected in the accumulator 6, and to prevent the refrigerating machine oil in the refrigerating apparatus 1 from decreasing. Since the refrigerating machine oil dissolved in the liquid refrigerant is not collected, a predetermined amount of the refrigerating machine oil is maintained in the refrigerating device 1. Therefore, the refrigeration apparatus can be easily operated without any abnormality after adjusting the refrigerant amount.

Embodiment 8 FIG. FIG. 9 also shows an example of another embodiment of the present invention, which is a main part refrigerant circuit of a refrigeration apparatus. Except for FIG. 9, the refrigeration apparatus is configured in the same manner as in FIG. In the drawing, the same reference numerals as those in FIG. 1 described above denote corresponding parts, and 27 is a refrigerating machine oil supply container, the lower side of which is connected to a first supply port 28 provided at the upper part of the accumulator 6, and the upper side is at the upper part of the accumulator 6. It is connected to the second supply port 29 provided.

In the refrigerating apparatus 1 configured as described above, by collecting the liquid refrigerant in the accumulator 6, it is possible to collect a refrigerant containing a higher boiling point refrigerant than the composition of the charged mixed refrigerant. Thus, by recovering the gas refrigerant in the accumulator 6, it is possible to recover a refrigerant containing a low boiling point refrigerant more than the composition of the charged mixed refrigerant. Therefore, although detailed description is omitted, the same operation as the embodiment of FIG. 1 can be obtained in the embodiment of FIG.

In the embodiment of FIG. 9, a refrigerating machine oil supply container 27 is provided instead of providing the oil separating device 25 of the embodiment of FIG. Then, the amount of the refrigerating machine oil dissolved in the liquid refrigerant of the accumulator 6 to be recovered is estimated, and the refrigerating machine oil amount is replenished to the accumulator 6 from the refrigerating machine oil supply container 27.

As a result, the refrigerating machine oil is recovered at the same time when the liquid refrigerant is recovered in the accumulator 6,
The replenishment can prevent the refrigerating machine oil in the refrigerating apparatus 1 from decreasing. As a result, a predetermined amount of refrigerating machine oil is maintained in the refrigerating device 1. Therefore, the refrigeration apparatus can be easily operated without any abnormality after adjusting the refrigerant amount. In addition,
The amount of the refrigerating machine oil dissolved in the liquid refrigerant can be estimated from the collected amount of the liquid refrigerant and the solubility of the refrigerating machine oil. The refrigerating machine oil drops from the refrigerating machine oil supply container 28 to the accumulator 6 by gravity.

[0075]

As described above, the present invention relates to a refrigeration system in which a compressor, a condenser, an expansion device, an evaporator, and an accumulator are sequentially connected and uses a non-azeotropic mixed refrigerant. The first flow rate control valve connected to the first refrigerant recovery port provided in the refrigeration unit recovers the refrigerant containing a low boiling point refrigerant more than the composition of the mixed refrigerant filled in the refrigeration apparatus, provided in the refrigerant circuit The second flow rate control valve connected to the second refrigerant recovery port recovers a refrigerant containing more refrigerant having a higher boiling point than the composition of the mixed refrigerant filled in the refrigeration apparatus.

As a result, the refrigerant containing a higher boiling point refrigerant than the composition of the non-azeotropic mixed refrigerant charged into the refrigeration system is recovered. Also, a refrigerant containing a large amount of low boiling point refrigerant is recovered. For this reason, the composition of the mixed refrigerant remaining in the refrigeration apparatus does not change due to the refrigerant recovery.

Therefore, the amount of the refrigerant can be adjusted without changing the composition of the non-azeotropic refrigerant mixture, and the refrigerant may leak from the refrigeration system due to an abnormality in the operating pressure of the refrigeration system, etc.
This has the effect of eliminating problems such as damage to the refrigeration system. Further, there is an effect that it is easy to maintain the normal operation after adjusting the refrigerant amount.

Further, as described above, in the present invention, the first refrigerant recovery port is provided at the location corresponding to the gas refrigerant of the accumulator, so that the refrigerant having a low boiling point is contained more than the composition of the mixed refrigerant filled in the refrigeration system. It recovers the refrigerant.

As a result, the refrigerant containing a higher boiling point refrigerant than the composition of the non-azeotropic mixed refrigerant charged in the refrigeration system is recovered, and, together with this recovery, the composition of the charged non-azeotropic mixed refrigerant is reduced. The refrigerant containing a large amount of low boiling point refrigerant is recovered from the gas refrigerant portion of the accumulator. For this reason,
The composition of the mixed refrigerant remaining in the refrigeration apparatus does not change due to the refrigerant recovery.

Therefore, the amount of the refrigerant can be adjusted without changing the composition of the non-azeotropic mixed refrigerant, and the refrigerant may leak from the refrigeration system due to an abnormality in the operating pressure of the refrigeration system, etc.
This has the effect of eliminating problems such as damage to the refrigeration system. Further, there is an effect that it is easy to maintain the normal operation after adjusting the refrigerant amount.

As described above, according to the present invention, the first refrigerant recovery port is provided at a position corresponding to the gas refrigerant in the refrigerant circuit at the outlet of the compressor, and the refrigerant having a boiling point lower than the composition of the mixed refrigerant charged in the refrigeration system is provided. Recovers a refrigerant containing a large amount of water.

As a result, the refrigerant containing a higher boiling point refrigerant than the composition of the non-azeotropic mixed refrigerant charged into the refrigeration system is recovered, and, along with the recovery, the composition of the charged non-azeotropic mixed refrigerant is recovered. A refrigerant containing a large amount of low-boiling refrigerant is recovered from a portion corresponding to a gas refrigerant in a refrigerant circuit at a compressor outlet.
For this reason, the composition of the mixed refrigerant remaining in the refrigeration apparatus does not change due to the refrigerant recovery.

Therefore, the amount of the refrigerant can be adjusted without changing the composition of the non-azeotropic refrigerant mixture, and the refrigerant may leak from the refrigeration system due to an abnormality in the operating pressure of the refrigeration system, etc.
This has the effect of eliminating problems such as damage to the refrigeration system. Further, there is an effect that it is easy to maintain the normal operation after adjusting the refrigerant amount.

As described above, according to the present invention, the first refrigerant recovery port is provided at a position corresponding to the liquid refrigerant in the refrigerant circuit at the outlet of the condenser, so that the refrigerant having a boiling point lower than the composition of the mixed refrigerant filled in the refrigeration system. Recovers a refrigerant containing a large amount of water.

As a result, the refrigerant containing a higher boiling point refrigerant than the composition of the non-azeotropic mixed refrigerant charged in the refrigeration system is recovered, and, along with the recovery, the composition of the charged non-azeotropic mixed refrigerant is recovered. The refrigerant containing a large amount of low-boiling-point refrigerant is recovered from a portion corresponding to the liquid refrigerant in the refrigerant circuit at the outlet of the condenser. For this reason, the composition of the mixed refrigerant remaining in the refrigeration apparatus does not change due to the refrigerant recovery.

Therefore, the amount of the refrigerant can be adjusted without changing the composition of the non-azeotropic refrigerant mixture, and the refrigerant may leak from the refrigeration system due to an abnormality in the operating pressure of the refrigeration system, etc.
This has the effect of eliminating problems such as damage to the refrigeration system. Further, there is an effect that it is easy to maintain the normal operation after adjusting the refrigerant amount.

Further, as described above, in the present invention, the second refrigerant recovery port is provided at the location corresponding to the liquid refrigerant of the accumulator, and the refrigerant having a higher boiling point than the composition of the mixed refrigerant charged into the refrigeration system is contained. It recovers the refrigerant.

As a result, a refrigerant containing a refrigerant having a lower boiling point than the composition of the non-azeotropic mixed refrigerant charged in the refrigeration system is recovered. The refrigerant containing a large amount of high-boiling refrigerant is recovered from the liquid refrigerant portion of the accumulator. For this reason, the composition of the mixed refrigerant remaining in the refrigeration apparatus does not change due to the refrigerant recovery.

Therefore, the amount of the refrigerant can be adjusted without changing the composition of the non-azeotropic refrigerant mixture, and the refrigerant may leak from the refrigeration system due to an abnormality in the operating pressure of the refrigeration system, etc.
This has the effect of eliminating problems such as damage to the refrigeration system. Further, there is an effect that it is easy to maintain the normal operation after adjusting the refrigerant amount.

Further, as described above, the present invention recovers the refrigerant recovered from the first refrigerant recovery port and the refrigerant recovered from the second refrigerant recovery port at a predetermined ratio.

As a result, the refrigerant containing a higher boiling point refrigerant than the composition of the non-azeotropic mixed refrigerant charged in the refrigeration system is recovered. Also, a refrigerant containing a large amount of low boiling point refrigerant is recovered. Moreover, the recovered amount of the refrigerant containing a large amount of the high-boiling-point refrigerant and the recovered amount of the refrigerant containing a large amount of the low-boiling-point refrigerant are recovered at a predetermined ratio. For this reason, the composition of the mixed refrigerant remaining in the refrigeration apparatus does not change due to the refrigerant recovery.

Therefore, the amount of the refrigerant can be adjusted without fluctuation in the composition of the non-azeotropic mixed refrigerant, and the refrigerant may leak from the refrigeration system due to an abnormality in the operating pressure of the refrigeration system, etc.
This has the effect of eliminating problems such as damage to the refrigeration system. Further, there is an effect that it is easy to maintain the normal operation after adjusting the refrigerant amount.

Further, as described above, the present invention provides:
The ratio between the refrigerant recovery amount from the first refrigerant recovery port and the refrigerant recovery amount from the second refrigerant recovery port is determined based on the circulation composition of the refrigerant in the refrigerating device by the circulation composition detection device.

As a result, the refrigerant containing a higher boiling point refrigerant than the composition of the non-azeotropic mixed refrigerant charged in the refrigeration system is recovered, and, along with the recovery, the composition of the charged non-azeotropic mixed refrigerant is recovered. Also, a refrigerant containing a large amount of low boiling point refrigerant is recovered. Moreover, the ratio of the recovered amount of the refrigerant containing a high boiling point refrigerant to the recovered amount of the refrigerant containing a large amount of the low boiling point refrigerant is
It is determined by the circulation composition of the refrigerant in the refrigeration system by the circulation composition detection device. For this reason, the composition of the mixed refrigerant remaining in the refrigeration apparatus does not change due to the refrigerant recovery.

Therefore, the amount of the refrigerant can be adjusted without changing the composition of the non-azeotropic refrigerant mixture, and the refrigerant may leak from the refrigeration system due to an abnormality in the operating pressure of the refrigeration system, etc.
This has the effect of eliminating problems such as damage to the refrigeration system. Further, there is an effect that it is easy to maintain the normal operation after adjusting the refrigerant amount.

Further, as described above, the present invention is based on the circulating composition estimated from the total refrigerant amount charged and the surplus refrigerant ratio based on the surplus refrigerant amount of the accumulator, and the refrigerant recovery amount from the first refrigerant recovery port and the second refrigerant recovery amount. It is for determining the ratio with respect to the refrigerant recovery amount from the refrigerant recovery port.

As a result, the refrigerant containing a higher-boiling-point refrigerant than the composition of the non-azeotropic mixed refrigerant charged into the refrigeration system is recovered, and, along with the recovery, the composition of the charged non-azeotropic mixed refrigerant is reduced. Also, a refrigerant containing a large amount of low boiling point refrigerant is recovered. Moreover, the ratio of the recovered amount of the refrigerant containing a high boiling point refrigerant to the recovered amount of the refrigerant containing a large amount of the low boiling point refrigerant is
It is determined by the circulation composition estimated from the surplus refrigerant rate based on the total refrigerant amount charged and the surplus refrigerant amount of the accumulator. For this reason, the composition of the mixed refrigerant remaining in the refrigeration apparatus does not change due to the refrigerant recovery.

Therefore, the amount of the refrigerant can be adjusted without fluctuation of the composition of the non-azeotropic mixed refrigerant, and the refrigerant may leak from the refrigeration system due to an abnormality in the operating pressure of the refrigeration system, etc.
This has the effect of eliminating problems such as damage to the refrigeration system. Further, there is an effect that it is easy to maintain the normal operation after adjusting the refrigerant amount.

As described above, according to the present invention, the composition of the refrigerant recovered from the first refrigerant recovery port is detected by the detecting means, and based on the result, the amount of the refrigerant recovered from the first refrigerant recovery port and the second refrigerant recovery amount are detected. It is for determining the ratio with respect to the refrigerant recovery amount from the refrigerant recovery port.

As a result, the refrigerant containing a higher boiling point refrigerant than the composition of the non-azeotropic mixed refrigerant charged into the refrigeration system is recovered. Also, a refrigerant containing a large amount of low boiling point refrigerant is recovered. Moreover, the ratio of the recovered amount of the refrigerant containing a high boiling point refrigerant to the recovered amount of the refrigerant containing a large amount of the low boiling point refrigerant is
The composition of the refrigerant recovered from the first refrigerant recovery port is detected by the detection means and is determined based on the result. For this reason, the composition of the mixed refrigerant remaining in the refrigeration apparatus does not change due to the refrigerant recovery.

Therefore, the amount of the refrigerant can be adjusted without changing the composition of the non-azeotropic mixed refrigerant, and the refrigerant may leak from the refrigeration system due to an abnormality in the operating pressure of the refrigeration system, etc.
This has the effect of eliminating problems such as damage to the refrigeration system. Further, there is an effect that it is easy to maintain the normal operation after adjusting the refrigerant amount.

As described above, according to the present invention, the composition of the refrigerant recovered from the second refrigerant recovery port is detected by the detecting means, and based on the result, the amount of refrigerant recovered from the first refrigerant recovery port and the second refrigerant recovery amount are detected. It is for determining the ratio with respect to the refrigerant recovery amount from the refrigerant recovery port.

As a result, the refrigerant containing a higher-boiling-point refrigerant than the composition of the non-azeotropic mixed refrigerant charged in the refrigeration system is recovered. Also, a refrigerant containing a large amount of low boiling point refrigerant is recovered. Moreover, the ratio of the recovered amount of the refrigerant containing a high boiling point refrigerant to the recovered amount of the refrigerant containing a large amount of the low boiling point refrigerant is
The composition of the refrigerant recovered from the second refrigerant recovery port is detected by the detection means and is determined based on the result. For this reason, the composition of the mixed refrigerant remaining in the refrigeration apparatus does not change due to the refrigerant recovery.

Therefore, the amount of the refrigerant can be adjusted without fluctuation in the composition of the non-azeotropic refrigerant mixture, and the refrigerant may leak from the refrigeration system due to an abnormality in the operating pressure of the refrigeration system, etc.
This has the effect of eliminating problems such as damage to the refrigeration system. Further, there is an effect that it is easy to maintain the normal operation after adjusting the refrigerant amount.

Further, as described above, the present invention processes the refrigerant recovered from the second refrigerant recovery port by the oil separation device, and recovers only the refrigerant after the refrigerating machine oil is separated.

Then, a refrigerant containing a refrigerant having a lower boiling point than the composition of the non-azeotropic mixed refrigerant charged in the refrigeration system is recovered. A refrigerant containing a large amount of high-boiling refrigerant is recovered from a liquid refrigerant portion of the accumulator. As a result, the composition of the mixed refrigerant remaining in the refrigeration apparatus does not change due to refrigerant recovery.

Therefore, the amount of the refrigerant can be adjusted without changing the composition of the non-azeotropic mixed refrigerant, and the refrigerant may leak from the refrigeration system due to an abnormality in the operating pressure of the refrigeration system, etc.
This has the effect of eliminating problems such as damage to the refrigeration system. Further, there is an effect that it is easy to maintain the normal operation after adjusting the refrigerant amount.

Further, the liquid refrigerant in which the refrigerating machine oil is dissolved is separated into a gas refrigerant and a refrigerating machine oil by an oil separator, and only the separated gas refrigerant is recovered, and the refrigerating machine oil is returned to the pressure machine. Therefore, it is possible to prevent the refrigerating machine oil from being collected at the same time as the liquid refrigerant is collected, and to prevent the refrigerating machine oil in the refrigerating apparatus from decreasing. As a result, a predetermined amount of the refrigerating machine oil is maintained in the refrigerating device, so that even if the amount of the refrigerant is adjusted, there is an effect that the normal operation of the refrigerating device is facilitated thereafter.

As described above, the present invention replenishes the refrigerating machine oil supply container with the refrigerating machine oil amount corresponding to the refrigerating machine oil amount in the refrigerant recovered from the second refrigerant recovery port.

Then, a refrigerant containing a refrigerant having a lower boiling point than the composition of the non-azeotropic mixed refrigerant charged in the refrigerating apparatus is recovered. A refrigerant containing a large amount of high-boiling refrigerant is recovered from a liquid refrigerant portion of the accumulator. As a result, the composition of the mixed refrigerant remaining in the refrigeration apparatus does not change due to refrigerant recovery.

Therefore, the amount of the refrigerant can be adjusted without changing the composition of the non-azeotropic mixed refrigerant, and the refrigerant may leak from the refrigeration system due to an abnormality in the operating pressure of the refrigeration system, etc.
This has the effect of eliminating problems such as damage to the refrigeration system. Further, there is an effect that it is easy to maintain the normal operation after adjusting the refrigerant amount.

Further, the refrigerating machine oil amount corresponding to the refrigerating machine oil amount in the refrigerant recovered from the second refrigerant recovery port is replenished from the refrigerating machine oil supply container. Therefore, even if the refrigerating machine oil is collected at the same time as the liquid refrigerant is collected, a decrease in the refrigerating machine oil in the refrigerating apparatus can be prevented. Therefore, since a predetermined amount of the refrigerating machine oil is maintained in the refrigerating apparatus, even if the refrigerant amount is adjusted, there is an effect that the normal operation of the refrigerating apparatus after that is facilitated.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of a refrigeration apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a refrigerant circuit diagram of a refrigeration apparatus according to Embodiment 2 of the present invention.

FIG. 3 is a refrigerant circuit diagram of a refrigeration apparatus showing a third embodiment of the present invention.

FIG. 4 is a refrigerant circuit diagram of a refrigeration apparatus showing Embodiment 4 of the present invention.

5 is a graph showing a relationship between a surplus refrigerant rate and a circulation composition in the refrigeration apparatus of FIG.

FIG. 6 is a refrigerant circuit diagram of a refrigeration apparatus showing Embodiment 5 of the present invention.

FIG. 7 is a refrigerant circuit diagram of a refrigeration apparatus showing Embodiment 6 of the present invention.

FIG. 8 is a refrigerant circuit diagram of a refrigeration apparatus showing a seventh embodiment of the present invention.

FIG. 9 is a main part refrigerant circuit of a refrigeration apparatus showing an eighth embodiment of the present invention.

FIG. 10 is a refrigerant circuit diagram of a refrigeration apparatus illustrating a conventional refrigerant recovery method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Refrigeration apparatus, 2 compressors, 3 condensers, 4 expansion apparatuses, 5 evaporators, 6 accumulators, 9 first refrigerant recovery ports, 10 second refrigerant recovery ports, 11 first flow control valves, 12 second flow control valves , 14 first refrigerant recovery port, 15 first refrigerant recovery port, 16 circulating composition detecting device, 23 detecting means, 25 oil separating device, 26 refrigerating machine oil supply container.

Claims (12)

[Claims] 1. A refrigeration system in which a compressor, a condenser, an expansion device, an evaporator, and an accumulator are sequentially connected and use a non-azeotropic mixed refrigerant, a first refrigerant recovery port provided in a refrigerant circuit of the refrigeration system. The first flow rate control valve connected to the refrigeration unit recovers the refrigerant containing a low boiling point refrigerant more than the composition of the mixed refrigerant filled in the refrigeration apparatus, and connects to the second refrigerant recovery port provided in the refrigerant circuit. A refrigerant recovery method for recovering a refrigerant containing more refrigerant having a higher boiling point than the composition of the mixed refrigerant by the second flow control valve. 2. The method according to claim 1, wherein the first refrigerant recovery port is provided at a location corresponding to the gas refrigerant of the accumulator, and recovers the refrigerant containing a low boiling point refrigerant more than the composition of the mixed refrigerant charged in the refrigeration system. The refrigerant recovery method according to claim 1. 3. A first refrigerant recovery port is provided at a position corresponding to a gas refrigerant in a refrigerant circuit at a compressor outlet, and recovers a refrigerant containing a low boiling point refrigerant more than a composition of a mixed refrigerant filled in a refrigeration system. The method for recovering refrigerant according to claim 1, wherein: 4. A first refrigerant recovery port is provided at a position corresponding to a liquid refrigerant in a refrigerant circuit at a condenser outlet, and recovers a refrigerant containing a low boiling point refrigerant more than a composition of a mixed refrigerant filled in a refrigeration system. The method for recovering refrigerant according to claim 1, wherein: 5. The method according to claim 1, wherein a second refrigerant recovery port is provided at a location corresponding to the liquid refrigerant of the accumulator, and recovers a refrigerant containing a higher boiling point refrigerant than the composition of the mixed refrigerant charged in the refrigeration system. The refrigerant recovery method according to claim 1. 6. The refrigerant recovery method according to claim 1, wherein the refrigerant recovery amount from the first refrigerant recovery port and the refrigerant recovery amount from the second refrigerant recovery port are recovered at a predetermined ratio. 7. The ratio of the amount of refrigerant recovered from the first refrigerant recovery port to the amount of refrigerant recovered from the second refrigerant recovery port is determined based on the circulating composition of the refrigerant in the refrigeration system by the circulating composition detecting device. The refrigerant recovery method according to claim 1. 8. A refrigerant recovery amount from a first refrigerant recovery port and a refrigerant recovery amount from a second refrigerant recovery port according to a circulation composition estimated from a total refrigerant amount charged and a surplus refrigerant ratio based on a surplus refrigerant amount of an accumulator. The method according to claim 1, wherein the ratio is determined. 9. The composition of the refrigerant recovered from the first refrigerant recovery port is detected by the detecting means, and the result indicates that the refrigerant recovery amount from the first refrigerant recovery port and the refrigerant recovery amount from the second refrigerant recovery port are determined. The refrigerant recovery method according to claim 1, wherein the ratio of the refrigerant is determined. 10. The composition of the refrigerant recovered from the second refrigerant recovery port is detected by the detection means, and the result indicates that the refrigerant recovery amount from the first refrigerant recovery port and the refrigerant recovery amount from the second refrigerant recovery port are determined. The refrigerant recovery method according to claim 1, wherein the ratio of the refrigerant is determined. 11. The refrigerant recovery method according to claim 5, wherein the refrigerant recovered from the second refrigerant recovery port is processed by an oil separator, and only the refrigerant after oil separation of the refrigerator is recovered. 12. The refrigerant recovery method according to claim 5, wherein a refrigerating machine oil amount corresponding to the refrigerating machine oil amount in the refrigerant recovered from the second refrigerant recovery port is replenished from the refrigerating machine oil supply container.