JPH0727451A - Pressure controlling method in recovering and gas extracting device and pressure controlling mechanism - Google Patents

Abstract

PURPOSE:To prevent a poor returning of a refrigerant liquid by a method wherein a technology for recovering a refrigerant for a freezer and a technology for extracting a non-condensed gas mixed in a refrigerant gas are improved and a pressure balance within a recovering device and a gas extracting device is controlled. CONSTITUTION:There is provided a small-sized freezer 22. There is also provided a pressure sensor P for use in sensing a pressure within a gas-liquid separator 4 which is a closed container forcedly cooled by the small-sized freezer. In the case that a pressure within the gas-liquid separator 4 is lower than a predetermined pressure, a solenoid switch 42 is turned OFF through a solenoid switch controlling device 43 so as to stop an operation of the small- sized freezer 22. In addition, there is provided a level sensor L so as to stop an operation of the small-sized freezer 22 when a level of refrigerant liquid within the gas-liquid separator 4 is higher than a predetermined position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant tank in which a refrigerant in a refrigerating tank is stored prior to disassembling, when disassembling, inspecting or maintaining an equipment device such as a refrigerator for enclosing a refrigerant fluid for performing a refrigerating cycle. And a method for discharging (recovering) the non-condensable gas leaking into the refrigerator to the outside of the refrigerator (bleeding) and a method therefor. It relates to a technique for controlling pressure so as not to be disturbed.

[0002]

2. Description of the Related Art In general, a refrigerator has a refrigerant substance (for example, CFC / R11) having a boiling point near room temperature sealed and sealed,
A refrigeration cycle of evaporation → compression → condensation → decompression → (evaporation) is performed. When disassembling (including partial disassembling) to inspect and maintain this refrigerator, the refrigerant is diffused into the atmosphere. To prevent this, the refrigerant is previously drawn from the refrigeration system of the refrigerator and collected in the refrigerant tank. After the temporary storage, the inspection and maintenance are completed, the refrigerant in the refrigerant tank is returned to the refrigerator. In a refrigerator, a non-condensable gas such as leaked air and water vapor are generally mixed together with a refrigerant gas and a refrigerant liquid. Refrigerant liquid can be relatively easily recovered in a container such as a refrigerant tank, and the refrigerant liquid is extracted prior to the recovery of the refrigerant gas. Omit it. The refrigerant gas needs to be liquefied and recovered, and the non-condensable gas and water vapor need to be separated from the refrigerant. FIG. 3 is a system diagram showing a conventional refrigerant gas recovery device. Refrigerator 1 is condenser 1
A, the evaporator 1b, and the compressor 1c constitute a refrigeration system, and a refrigerant (for example, Freon R11) is enclosed and hermetically sealed. In order to recover the refrigerant gas from the refrigeration system to the refrigerant tank 5, the refrigerant gas in the refrigerator 1 is sucked and pumped by the compressor 2 and cooled in the condenser 3 to be liquefied. A non-condensable gas such as air is mixed in the refrigerant gas, and the air also contains some water vapor. Therefore, the refrigerant or the like liquefied in the condenser 3 is guided to the gas-liquid separator 4 so that only the refrigerant liquid is recovered from the float valve 4a to the refrigerant tank 5, and the non-condensing gas component is discharged into the atmosphere from the discharge valve 4b. . This gas component contains the refrigerant gas that has not condensed. W is a viewing window for observing the accumulation state of liquefied water, and v is a drain valve.

Since the refrigerant was expensive in the past (for example, before the high economic growth in the 1955's), it was an economic and technical idea to recover the refrigerant without dissipating it. Therefore, the refrigerant was recovered as in the conventional example shown in FIG. 3, but as far as this idea is concerned, an effort to thoroughly collect the refrigerant even at a higher cost than the refrigerant to be recovered. Was not done. Showa 40
Various pollution became a social problem in the 1960s,
In the 1980s, global environmental issues such as ozone layer destruction caused by refrigerants and solvents such as CFCs were discussed internationally, and CFCs were recovered to the limit even at a cost higher than the monetary value of CFCs recovered. , The time has come when fluorocarbons must not be released into the atmosphere. From this point of view, looking at the conventional technique of FIG.
Even if the refrigerant gas in the inside is exhausted to the utmost, the gas pressure inside the machine generally falls only to about -650 mmHg. This -65
Refrigerant gas of 0 mmHg is released into the atmosphere during disassembly and maintenance. The residual gas pressure inside this machine is -750 to about 760
In order to lower the pressure to mmHg, as shown in FIG.
The technique of using is also known. However, in the conventional example of FIG. 4, the residual gas pressure in the machine can be lowered to about −760 mmHg, but the discharge pressure of the vacuum pump 9 is low, so that the non-condensable gas pressure in the upper space in the gas-liquid separator 4 is 0. .3 Kgf
/ Cm ² g only up to about. In the non-condensable gas, a partial pressure of uncondensed refrigerant gas corresponding to the condensation temperature in the condenser 3 is mixed, and the refrigerant gas concentration is inversely proportional to the pressure in the gas-liquid separator 4, When the pressure is low, the partial pressure of the refrigerant gas is relatively high, and the uncondensed refrigerant gas concentration is high.
Therefore, the high-concentration uncondensed refrigerant gas is emitted along with the non-condensable gas released from the release valve 4b into the atmosphere. In order to solve the problems of the conventional example described with reference to FIGS. 3 and 4, a configuration in which the compressor 2 is connected in series on the downstream side of the vacuum pump 9 as shown in FIG. 5 is effective. This configuration is an invention relating to an unknown prior application that was created by the present inventors and is being separately applied by the present applicant (Japanese Patent Application No. 4-156912). According to the invention of the above-mentioned prior application, the residual refrigerant gas pressure in the refrigerator 1 is ideally lowered (about -760 mmHg),
Moreover, the pressure of the non-condensable gas in the gas-liquid separator 4 can be increased (for example, 5 Kgf / cm ² g), so that the amount of the refrigerant remaining in the refrigerator and diffused into the atmosphere, and the discharge valve. Therefore, the total amount of the non-condensable gas and the amount of the refrigerant that is diffused along with the non-condensable gas can be reduced to a level that can be regarded as zero in practice.

What has been described above with reference to FIGS. 3 to 5 is the prior art relating to the recovery of the refrigerant in the refrigerator, and the technical point is that the refrigerant enclosed in the refrigerator is in the atmosphere. The non-condensable gas leaked into the refrigerant gas was released into the atmosphere without being diffused into the atmosphere.

On the other hand, regarding the maintenance of the refrigerator,
There is an important bleeding operation as well as the aforementioned recovery. Regarding this extraction air, the refrigerant enclosed in the refrigerator becomes a negative pressure compared to the atmospheric pressure while repeating the refrigeration cycle of evaporation → compression → condensation → decompression → (evaporation) as described above. To pass. Therefore, there is a possibility that non-condensable gas (such as air) may be mixed in the refrigerant gas. If non-condensable gas is mixed in the refrigerant gas, it will reduce the capacity and efficiency of the refrigerator, or induce rusting in the refrigerator, so the mixed non-condensable gas is separated and released into the atmosphere. Operation (bleeding) is required. The technical point in this bleeding operation is also how to reduce the content rate of the refrigerant gas released into the atmosphere with the non-condensable gas released into the atmosphere. As described above, there are many technically common parts between the extraction operation and the collection operation. In the conventional recovery device shown in FIG. 3, instead of injecting the refrigerant liquid accumulated at the bottom of the gas-liquid separator 4 into the refrigerant tank 5, the refrigerant liquid is returned to the evaporator 1b of the refrigerator 1. If the piping is modified, it will look like Figure 6. In FIG. 6, since the non-condensable gas leaking into the refrigerator 1 is lighter than the refrigerant gas, it collects in the condenser 1a and is mixed with the refrigerant gas to form a mixed gas. The mixed gas is sucked by the compressor 2 and sent under pressure, cooled by the condenser 3 and guided to the gas-liquid separator 4. At this time, the fluid flowing into the gas-liquid separator 4 is mainly a gas-liquid mixed flow of a refrigerant gas, a non-condensable gas, and a refrigerant liquid, which contains some water vapor and fine water droplets. There is. The gas-liquid mixed flow is separated by the gas-liquid separator 4, and the refrigerant liquid is returned to the evaporator 1b of the refrigerator 1 via the float valve 4a. The water is discharged from the drain valve v, and the non-condensed gas and the uncondensed refrigerant gas are discharged to the atmosphere from the discharge valve 4b.

In the recovery device shown in FIG. 5 and the extraction device shown in FIG. 6, when the non-condensable gas accumulated in the upper space of the gas-liquid separator 4 is released from the release valve 4b into the atmosphere,
Some refrigerant gas is entrained and emitted together. To reduce the content rate of the accompanying refrigerant gas, the gas-liquid separator 4 is used.
It is effective to strongly cool the mixed gas therein (mainly composed of non-condensable gas and refrigerant gas). FIG. 7 shows an example in which the mixed gas in the gas-liquid separator in the recovery apparatus shown in FIG. 5 is improved so as to be strongly cooled, and the invention of the prior application (Japanese Patent Application No. 4-1569).
FIG. 12 is a system diagram of a recovery device according to an unknown prior art proposed in No. 12; To briefly describe this configuration, the gas-liquid separator 4 in the conventional example of FIG. 5 is provided with a small refrigerator 22. In the present invention, the small refrigerator refers to a refrigerator having a smaller capacity and a smaller capacity than the refrigerator 1 which is the target of the refrigerant recovery operation. The gas-liquid separator 4'of this example has a cooling pipe 4 inside.
c is provided. On the other hand, the small refrigerator 22 is the compressor 22
a, a condenser 22b and an expansion valve 22c are provided, and a cooling fluid 22d is supplied to the cooling pipe 4c for circulation. According to this example, the refrigerant gas is strongly cooled in the gas-liquid separator 4'and its vapor pressure is lowered, so that the concentration of the refrigerant gas accompanying the non-condensable gas released from the release valve 4b is further lowered. Since the refrigerant gas is strongly cooled as described above, if the cooling temperature is lower than the freezing point of water, if the refrigerant gas contains water vapor, frost is generated in the gas-liquid separator 4 ', and There is a risk of freezing and obstructing the operation of valves. Therefore, it is desirable to remove the water vapor by providing the dryer 23 on the inflow side of the gas-liquid separator 4'as shown by the phantom line. As can be easily understood from the conventional example of FIG.
The cooling fluid that circulates in the cooling pipe 4c in the gas-liquid separator 4'and strongly cools the refrigerant gas is independent of the small refrigerator 22 installed.
It is also possible to use cold fluid such as cold water or a refrigerant supplied from another cooling device.

[0007] FIG. 8 shows an unknown prior application (Japanese Patent Application No. Hei 4) in which a small refrigerator 22 is provided to cool the refrigerant gas strongly.
-181035) shows an example of an extraction device and is a schematic system diagram. The gas-liquid separator 4 shown in FIG. 8 is provided with a cooling jacket 8, and a low-temperature refrigerant is supplied from the condenser 1a of the refrigerator 1 via the orifice 21 to mix the mixed gas in the gas-liquid separator 4. The (refrigerant gas + non-condensable gas) is cooled, and the non-condensable gas and the refrigerant liquid are efficiently separated. However, without releasing the gas accumulated in the gas-liquid separator 4 into the atmosphere as it is, the electromagnetic valve 14,
15 is operated to be introduced into the rectifier 9, and the low temperature fluid supplied from the small refrigerator 22 is circulated and circulated through the cooling pipe 9a for strong cooling. When the mixed gas introduced into the rectifier 9 is strongly cooled, the partial pressure of the refrigerant gas is remarkably reduced, and the refrigerant gas that exceeds saturation is condensed and is returned to the evaporator 1b of the refrigerator 1. . The pressure of the gas (almost pure non-condensable gas) accumulated in the upper space of the rectifier 9 is detected by the pressure sensor 9b, and when it reaches a predetermined value, it is discharged from the discharge unit 9c to the atmosphere.

If the mixed gas introduced into the rectifier 9 contains a large amount of water vapor, the cooling pipe 9a is frosted and the heat conduction is hindered. It has become so.

[0009]

The gas-liquid separator 4'in the recovery apparatus according to the invention of the prior application shown in FIG. 7 and the rectifier 9 shown in FIG. It is a closed room that is strongly cooled. The mixed gas (refrigerant gas + non-condensable gas) in these closed chambers is strongly cooled, the partial pressure of the refrigerant gas is reduced, and the content ratio of the refrigerant gas released along with the refrigerant is also reduced. However, there is a problem that a problem will occur if it is cooled too hard. The aspect of the failure differs depending on the recovery device and the extraction device, and will be described in order.

In FIG. 7, when the recovery device is stopped for a long period of time, the pressure in the gas-liquid separator 4'is 0 kgf / cm ² g (≈1 kgf / cm ² abs) due to minute leakage from the discharge valve 4 or the like.
It is a value close to. On the other hand, the pressure in the refrigerant tank 5 is about 1.78 Kgf / cm ² when the ambient temperature is high, for example, 40 ° C.
It is abs (vapor pressure of the refrigerant). Therefore, the pressure in the gas-liquid separator 4'is lower than the pressure in the refrigerant tank 5, and if the recovery operation is performed in such a state, the refrigerant liquid in the gas-liquid separator 4'will enter the refrigerant tank 5. It may happen that there is no inflow. In such a state, the refrigerant liquid accumulates on the bottom of the gas-liquid separator 4 ', and the collection work becomes congested. In such a case, the refrigerant liquid level in the gas-liquid separator 4'increases, causing an emergency stop of the device. Figure 8
The bleeding device shown in (1) is not always operated, but is operated for several hours regularly or at any time. The state of the inside of the rectifier 9 when the operation is restarted depends on the situation at the time when the previous extraction work is completed. Now, for example, immediately after the operation is restarted, it is strongly cooled to −20 ° C. and 0.16 Kgf / cm ² ab.
s (-0.84 Kgf / cm ² g). on the other hand,
The pressure inside the evaporator 1b of the refrigerator 1 is 0.41 at 0 ° C.
Kgf / cm ² abs, 0.62 Kgf / c at 10 ° C
m ² abs. Therefore, the refrigerant liquid accumulated at the bottom of the rectifier 9 cannot flow back to the evaporator 1b of the refrigerator 1,
The amount of the refrigerant liquid in the rectifier 9 increases, and the bleeding is not performed effectively. Even in such a case, the refrigerant liquid level in the rectifier 9 rises, leading to an emergency stop of the device.
The present invention has been made in view of the above circumstances, eliminates the imbalance of the pressure balance in the recovery device and the bleeding device, cannot inject into the refrigerant tank during the recovery work, and recirculates the refrigerant liquid during the bleeding work. The purpose is to provide a technology for preventing the disability.

[0011]

Next, the basic principle of the present invention will be briefly described. A closed container equipped with a small refrigerator (for example, a gas-liquid separator 4'in FIG. 7 or a rectifier 9 in FIG. 8). )
Is supercooled (with a small amount of non-condensable gas in the airtight container), the pressure in the airtight container is excessively lowered, and the refrigerant liquid accumulated therein cannot be delivered. It is effective to prevent overcooling, but in the first place, the recovery device and the bleeding device of the invention of the prior application, which are equipped with a small refrigerator, reduce the temperature (deep cooling) to reduce the accompanying release of the refrigerant gas. In view of such circumstances, the present invention does not detect the temperature in the closed container to control the temperature, but detects the pressure to control the operation of the small refrigerator. The reason is as follows. I. The direct cause of the inability to inject or reflux the refrigerant liquid is that the pressure in the closed container is relatively low as compared with the pressure in the mating container to be infused or refluxed. B. If the gas in the closed container is of a single type,
Alternatively, if it is an ideal gas, the pressure can be calculated by detecting the temperature. However, since the gas in the closed container is a mixed gas of a refrigerant gas and a non-condensable gas, and the mixing ratio is indefinite, the temperature and the pressure do not uniquely correspond to each other. The above is the basics of the present invention, but in the case of implementing the present invention, further detecting the liquid level of the refrigerant in the closed container as a safety device, and stopping the small refrigerator when the level rises above a specified value. Is desirable. The reason is that the liquid level of the refrigerant in the closed container rises abnormally,
This is because it means that the refrigerant liquid cannot be injected or the refrigerant liquid cannot be recirculated.

In order to prevent the refrigerant liquid from being unable to return on the basis of the above-mentioned principle, the pressure control method in the recovery device of the present invention is such that the mixed gas of the non-condensable gas and the refrigerant gas leaking into the refrigerator is cooled by the cooling pipe. Introduced into a closed container equipped with, refrigerated by a low-temperature fluid that flows through the cooling pipe supplied from a small refrigerator separate from the refrigerator, and introduces a refrigerant liquid in which the refrigerant gas is condensed into a refrigerant tank. In the device for collecting, the operation of the separate small refrigerator is controlled so that the pressure in the closed container equipped with the cooling pipe does not fall below a predetermined pressure. Further, the configuration of the pressure control mechanism of the present invention created to carry out the method of the invention, the mixed gas of the non-condensable gas and the refrigerant gas leaked into the refrigerator, in a closed container equipped with a cooling pipe. In a refrigerant recovery device for guiding and recovering a refrigerant liquid condensed by the refrigerant gas, which is strongly cooled by a low-temperature fluid that flows through the cooling pipe and is supplied from a small refrigerator separate from the refrigerator. A means for controlling the operation of the separate small refrigerator is provided so that the pressure in the closed container does not fall below a predetermined pressure.

Further, based on the above-mentioned principle, in order to prevent the refrigerant liquid from being unable to recirculate, the pressure control method of the extraction device according to the present invention is designed to remove the mixed gas of the non-condensable gas and the refrigerant gas leaking into the refrigerator. , Guided into an airtight container provided with a cooling pipe, strongly cooled by a low temperature fluid supplied from a small refrigerator separate from the refrigerator and flowing through the cooling pipe, and a refrigerant liquid in which the refrigerant gas is condensed is a refrigerator. In the bleeding device that recirculates to the evaporator, the operation of the separate small refrigerator is controlled so that the pressure in the closed container equipped with the cooling pipe does not fall below a predetermined pressure. Further, the configuration of the pressure control mechanism of the present invention for carrying out the method of the invention, the mixed gas of the non-condensable gas and the refrigerant gas leaked into the refrigerator,
Guided in a closed container equipped with a cooling pipe, is strongly cooled by a low-temperature fluid that flows through the cooling pipe supplied from a small refrigerator separate from the refrigerator, and the refrigerant gas condensed refrigerant liquid of the refrigerator The bleeding device that recirculates to the evaporator is characterized by being provided with a mechanism for controlling the operation of the separate small refrigerator so that the pressure in the closed container does not fall below a predetermined pressure.

[0014]

According to the above construction, the pressure in the closed container that is strongly cooled by the small refrigerator is detected, and regardless of the temperature in the closed container, if the detected pressure value is equal to or lower than the predetermined pressure, the small refrigerator is Stop the machine operation. For this reason, when the pressure of the mixed gas (refrigerant gas + non-condensable gas) in the closed container is low, it is not cooled strongly, and the non-returnable state is prevented. Such a function, when the recovery device or the bleeding device starts to operate, acts to delay the start of operation of the small refrigerator until the pressure in the closed container reaches a predetermined value. This has an effect of preventing the return (inflow into the refrigerant tank in the recovery device and return to the evaporator in the extraction device) from being disabled. Furthermore, if a level sensor for detecting the liquid level of the refrigerant in the closed container is provided, the device according to the present invention will not function normally due to some circumstances and the refrigerant liquid cannot be returned or is insufficiently returned. As a result, when the liquid level in the closed container rises, the abnormality can be detected and the operation of the small refrigerator can be stopped to function as a safety device.

[0015]

FIG. 1 is a system diagram showing a pressure control mechanism of a recovery device according to the present invention, in which the present invention is applied to the recovery device according to the previously unknown invention shown in FIG. The main part of the example is drawn. Next, different points from the configuration of FIG.
That is, matters improved by applying the present invention will be described. A pressure sensor P for detecting the internal pressure of the gas-liquid separator 4 which is a closed container into which the mixed gas (refrigerant gas + non-condensable gas) is provided, which includes the small refrigerator 22, and is accumulated in the closed container. A level sensor L for detecting the liquid level of the refrigerant liquid is provided, and the detection signal outputs of both sensors are input to the electromagnetic switch controller 43. On the other hand, an electromagnetic switch 42 is interposed and connected in a power supply circuit connecting the small refrigerator 22 and the small refrigerator power source 41. Compressor 22 of the small refrigerator 22
The fan motors for a and the condenser 22b are driven by the electric power supplied from the power supply 41, and stop operating when the power is cut off. When the pressure sensor detects a predetermined value P ₁ or more, the electromagnetic switch controller 43 to which the output signal is input turns on the electromagnetic switch 42. When a predetermined value P ₂ or less different from the above is detected, the electromagnetic switch 42 is turned off to turn the small refrigerator 2
2. Stop the cooling function of 2. The above values P ₁ and P ₂ can be set arbitrarily, but according to the research results of the present inventor, it is desirable that the predetermined pressure P ₁ be ² to 5 kgf / cm ² g. The width of this numerical range takes into consideration the characteristics of the recovery device, the environmental temperature, and changes in the type of refrigerant, but conditions may change within the range of climatic conditions and properties of the refrigerant substance used in Japan. Also, if the small refrigerator is operated at a pressure lower than this pressure range, there is a risk that defective refrigerant return may occur, and if the pressure is higher than this pressure range, refrigerant return failure does not occur, so the small refrigerator Stopping the operation of is useless and harmful. Further, the predetermined pressure P ₂ can be appropriately set in consideration of the operating characteristics of the pressure sensor, etc., but according to the research results of the present inventor, the predetermined pressure P ₂ is compared with the predetermined pressure P ₁ . Then 0.
If it is set low by 3 to 1.5 Kgf / cm ² g, good action and effect can be obtained. Further, the level sensor L is
When the liquid level of the refrigerant in the closed container rises, a liquid level signal is output to the electromagnetic switch controller 43. When this signal is input, the electromagnetic switch controller 43 turns off the electromagnetic switch. If the liquid level signal is output even though the operation of the small refrigerator 22 is controlled by the output signal of the pressure sensor P, it is estimated that an abnormality has occurred in one of the devices. Therefore, the cause is sought, and after the cause is eliminated, the operation is restarted. In the above-described embodiment, the pressure sensor P and the level sensor L open and close the power supply circuit via the electromagnetic switch controller 43. However, as can be easily understood from the above-mentioned structural function,
A pressure switch may be used instead of the pressure sensor, and a level switch may be used instead of the level sensor to directly control the opening and closing of the power supply circuit of the small refrigerator, which is within the technical scope of the present invention. Further, as in the present embodiment, not only opening and closing the power circuit of the small refrigerator,
It is also possible to control the refrigerating function via the thermostat of the small refrigerator, which belongs to the technical scope of the present invention. In the pressure control mechanism having the configuration described above with reference to FIG. 1, the operation of the small refrigerator 22 is stopped when the pressure in the gas-liquid separator 4, which is a closed container, is equal to or lower than the predetermined value P _2. There is no possibility that the inside of the hermetically sealed container will be overcooled and the refrigerant liquid will not return properly.

Next, an embodiment of the pressure control mechanism of the extraction apparatus according to the present invention will be described. FIG. 2 is a system diagram showing a pressure control mechanism of the bleeding device according to the present invention, which is a main part of an embodiment improved by applying the present invention to the bleeding device according to the previously unknown invention shown in FIG. Is drawn. Next, points different from the configuration of FIG. 8, that is, matters improved by applying the present invention will be described. A pressure sensor P provided with a small refrigerator 22 for detecting the internal pressure of a rectifier 9 which is a closed container into which a mixed gas (refrigerant gas + non-condensable gas) is introduced, and a refrigerant accumulated in the closed container. A level sensor L for detecting the liquid level of the liquid is provided, and the detection signal outputs of both of the above sensors are respectively provided by the electromagnetic switch controller 4
Input to 3. On the other hand, an electromagnetic switch 42 is interposed and connected in a power supply circuit connecting the small refrigerator 22 and the small refrigerator power source 41. The small refrigerator 22
The fan motors for the compressor 22a and the condenser 22b are driven by the electric power supplied from the power supply 41, and stop operating when the power is cut off. When the pressure sensor detects a predetermined value P ₁ or more, the electromagnetic switch controller 43 to which the output signal is input is controlled by the electromagnetic switch 42.
Turn on. When a predetermined value P ₂ different from the above is detected, the electromagnetic switch 42 is turned off to stop the cooling function of the small refrigerator 22. The above value P ₁ ,
The P _2, can be set arbitrarily, according to the research results of the inventors, -0.2 predetermined pressure P ₁ +
It is desirable to set it to 2.0 kgf / cm ² g. The width of this numerical range takes into consideration the characteristics of the extraction device, the environmental temperature and the variation of the type of refrigerant, but the conditions may change within the range of the climatic conditions and the properties of the refrigerant substance used in Japan. Also, if the small refrigerator is operated at a pressure lower than this pressure range, there is a risk that defective refrigerant return may occur, and if the pressure is higher than this pressure range, refrigerant return failure does not occur, so the small refrigerator Stopping the operation of is useless and harmful. In addition, the predetermined pressure P ₂
Can be appropriately set in consideration of the operating characteristics of the pressure sensor and the like, but according to the research results of the present inventor, the predetermined pressure P ₂
Relative to the predetermined pressure P ₁ is 0.1 to 1.5 kgf / cm ² g
Setting the value as low as possible gives good action and effect. The level sensor L outputs a liquid level signal to the electromagnetic switch controller 43 when the liquid level of the refrigerant in the closed container rises. When this signal is input, the electromagnetic switch controller 43 turns off the electromagnetic switch. If the liquid level signal is output even though the operation of the small refrigerator 22 is controlled by the output signal of the pressure sensor P, it is estimated that an abnormality has occurred in one of the devices. Therefore, the cause is sought, and after the cause is eliminated, the operation is restarted. In the above-mentioned embodiment, the pressure sensor P and the level sensor L open and close the power supply circuit via the electromagnetic switch controller 43. It is also possible to directly control the opening and closing of the power supply circuit of the small refrigerator by using a pressure switch and a level switch instead of the level sensor, which is within the technical scope of the present invention. Further, as in the present embodiment, it is not limited to opening and closing the power circuit of the small refrigerator, it is also possible to control the refrigeration function via the thermostat of the small refrigerator, within the technical scope of the present invention. Belong to. In the pressure control mechanism having the configuration described above with reference to FIG. 2, the operation of the small refrigerator 22 is stopped when the pressure in the rectifier 9, which is a closed container, is equal to or lower than the predetermined value P ₂ , so that the closed There is no possibility that the inside of the container will be overcooled and a defective return of the refrigerant liquid will occur.

[0017]

When the present invention is applied, the pressure in the closed container which is strongly cooled by the small refrigerator is detected, and the detected pressure value is below the predetermined pressure regardless of the temperature in the closed container. Stop the operation of the small refrigerator. For this reason,
When the pressure of the mixed gas (refrigerant gas + non-condensable gas) in the closed container is low, strong cooling is not performed, and the state of being unable to return is prevented. Such a function, when the recovery device or the bleeding device starts to operate, acts to delay the start of operation of the small refrigerator until the pressure in the closed container reaches a predetermined value. This has an effect of preventing the return (inflow into the refrigerant tank in the recovery device and return to the evaporator in the extraction device) from being disabled.
Furthermore, if a level sensor for detecting the liquid level of the refrigerant in the closed container is provided, the device according to the present invention will not function normally due to some circumstances and the refrigerant liquid cannot be returned or is insufficiently returned. Then, when the liquid level in the closed container rises, it has an excellent practical effect that it can function as a safety device such as detecting the abnormality and stopping the operation of the small refrigerator. There is a great deal of contribution to pollution prevention.

[Brief description of drawings]

FIG. 1 is a system diagram showing a pressure control mechanism of a recovery device according to the present invention, which is a main part of an embodiment improved by applying the present invention to the recovery device according to the previously unknown invention shown in FIG. The section is drawn.

FIG. 2 is a system diagram showing a pressure control mechanism of the bleeding device according to the present invention, showing the essential points of an embodiment improved by applying the present invention to the bleeding device according to the previously unknown invention shown in FIG. The section is drawn.

FIG. 3 is a system diagram showing a conventional refrigerant gas recovery device.

FIG. 4 is a system diagram showing a conventional refrigerant gas recovery device different from the above.

FIG. 5 is a system diagram showing a refrigerant recovery device according to the invention of the prior application (Japanese Patent Application No. 4-156912).

FIG. 6 is a system diagram showing a conventional example of an extraction device.

7 is an example in which the mixed gas in the gas-liquid separator in the recovery apparatus shown in FIG. 5 is improved to be strongly cooled, and is proposed in the invention of the prior application (Japanese Patent Application No. 4-156912). FIG. 3 is a system diagram of a collection device according to an unknown prior art.

FIG. 8 is an unknown prior application (Japanese Patent Application No. 4-18103) that is provided with a small refrigerator 22 to strongly cool the refrigerant gas.
5 is a schematic system diagram showing an example of an extraction device according to No. 5).

[Explanation of Codes] 1 ... Refrigerator, 1a ... Condenser, 1b ... Evaporator, 1c ... Compressor, 2 ... Compressor, 3 ... Condenser, 4, 4 '... Gas-liquid separator,
4a ... float valve, 4b ... discharge valve, 4c ... cooling pipe, 5 ...
Refrigerant tank, 9 ... rectifier, 9a ... Cooling pipe, 9b ... Pressure sensor, 9c ... Discharge unit, 15 ... Solenoid valve, 19 ... Vacuum pump, 21 ... Orifice, 22 ... Small refrigerator, 22a
... Compressor, 22b ... Condenser, 22c ... Expansion valve, 23 ... Dryer, 41 ... Small refrigerating power source, 42 ... Electromagnetic switch, 43 ... Electromagnetic switch controller, L ... Level sensor, P
… Pressure sensor.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Teruyoshi Miyatake 2-20-36 Takanawa, Minato-ku, Tokyo Hitachi Building Facility Engineering Co., Ltd.

Claims (20)

[Claims] 1. A mixed gas of a non-condensable gas and a refrigerant gas, which has leaked into the refrigerator, is introduced into a closed container having a cooling pipe, and is supplied from a small refrigerator separate from the refrigerator, In a device that strongly cools with a low temperature fluid flowing through a cooling pipe, and guides and collects a refrigerant liquid in which the refrigerant gas is condensed to a refrigerant tank, so that the pressure in the closed container equipped with the cooling pipe does not fall below a predetermined pressure. In addition, the pressure control method in the recovery device, characterized in that the operation of the separate small refrigerator is controlled. 2. The operation control of the separate small refrigerator is performed by detecting the pressure in the enclosure and operating the small refrigerator when the pressure reaches a predetermined pressure P ₁ or more, and a predetermined pressure P different from the above.
The pressure control method in the recovery device according to claim 1, wherein the small refrigerator is stopped when it becomes ₂ or less. 3. The predetermined pressure P ₁ is ^{2 to 5} kgf / cm ² g
And the predetermined pressure P ₂ is a value lower than the predetermined pressure P ₁ by 0.3 to 1.5 Kgf / cm ² in the recovery device according to claim 2. Pressure control method. 4. The liquid level of the refrigerant liquid in the hermetically sealed container is monitored, and when the liquid level reaches or exceeds a predetermined value, the operation of the separate small refrigerator is stopped. ,
A pressure control method in the recovery device according to claim 1. 5. A small refrigeration system, regardless of the pressure in the airtight container, until the liquid level falls below a predetermined value after the liquid level reaches or exceeds a predetermined value and the operation of the small refrigerator is stopped. When the recovery operation is continued with the operation of the machine stopped, the liquid level becomes lower than the predetermined value, and the pressure inside the enclosure becomes the predetermined pressure P ₁ or more, the recovery operation is continued. The pressure control method in the recovery device according to claim 4, wherein the operation of the small refrigerator is restarted. 6. A mixed gas of a non-condensable gas and a refrigerant gas, which has leaked into the refrigerator, is introduced into a closed container having a cooling pipe, and is supplied from a small refrigerator separate from the refrigerator, Refrigerant recovery device that strongly cools by a low-temperature fluid flowing through a cooling pipe and guides and recovers a refrigerant liquid in which the refrigerant gas is condensed to a refrigerant tank, in order to prevent the pressure in the sealing device from becoming equal to or lower than a predetermined pressure, A pressure control mechanism in a recovery device, characterized in that means for controlling the operation of the small body refrigerator is provided. 7. A pressure sensor for detecting the pressure in the hermetic container, and a controller for opening and closing a drive power supply circuit of the small refrigerator based on a detection signal output of the pressure sensor. The pressure control mechanism in the recovery device according to claim 6, which is characterized. 8. The controller turns on the power supply circuit when the pressure detected by the pressure sensor is equal to or higher than a predetermined pressure P _1, and turns on the power supply circuit when the pressure is equal to or lower than a predetermined pressure P ₂ different from the above.
In the structure for FF, the predetermined pressure P ₁ is ^{2 to 5} kgf / cm ² g, and the predetermined pressure P ₂ is 0.3 to ₁₀ % compared to the predetermined pressure P _1.
Characterized by a low value of 1.5 Kgf / cm ² ,
A pressure control mechanism in the recovery device according to claim 7. 9. A level sensor for detecting the liquid level of the refrigerant liquid in the hermetically sealed device is provided, and the controller turns off the power supply circuit when the detection value of the level sensor exceeds a predetermined value. The pressure control mechanism in the recovery device according to claim 7 or 8, characterized in that. 10. The controller according to claim 1, wherein after the level sensor detection value exceeds a predetermined value and the power is turned off, the level sensor detection value becomes lower than the predetermined value and the pressure sensor detection value is lower than the predetermined value. When the pressure is equal to or higher than the predetermined pressure P ₁ , turn on the power circuit
The pressure control mechanism in the recovery device according to claim 9, wherein the pressure control mechanism is N. 11. A mixed gas of a non-condensable gas and a refrigerant gas, which has leaked into the refrigerator, is introduced into a closed container provided with a cooling pipe, and is supplied from a small refrigerator separate from the refrigerator, Strongly cooled by a low-temperature fluid flowing through a cooling pipe, in a bleeding device for recirculating the refrigerant liquid in which the refrigerant gas is condensed to the evaporator of the refrigerator, the pressure in the closed container provided with the cooling pipe is equal to or lower than a predetermined pressure. The method of controlling the pressure in the bleeding device is characterized in that the operation of the separate small refrigerator is controlled so as not to occur. 12. The operation control of the separate small refrigerator comprises:
The pressure inside the airtight device is detected, and when the pressure reaches a predetermined pressure P ₁ or more, the small refrigerator is operated, and when the pressure becomes a predetermined pressure P ₂ or less different from the above, the small refrigerator is stopped. The pressure control method in the extraction device according to claim 11, which is characterized in that. 13. The predetermined pressure P ₁ is −0.2 to +.
2.0 kgf / cm ² g, and the predetermined pressure P ₂ is a value lower than the predetermined pressure P ₁ by 0.1 to 1.5 kgf / cm ^2. Item 13. A pressure control method in the extraction device according to item 12. 14. The liquid level of the refrigerant liquid in the hermetically sealed container is monitored, and when the liquid level reaches or exceeds a predetermined value, the operation of the separate small refrigerator is stopped. The pressure control method in the extraction device according to any one of claims 11 to 13. 15. A small refrigeration system, regardless of the pressure in the airtight container, until the liquid level falls below a predetermined value after the liquid level has exceeded a predetermined value and the operation of the small refrigerator has been stopped. Continue the bleeding operation with the operation of the machine stopped,
When the liquid level becomes lower than a predetermined value and the pressure in the closed vessel becomes a predetermined pressure P ₁ or more, the operation of the small refrigerator is restarted while continuing the extraction operation. The pressure control method in the extraction device according to claim 14. 16. A mixed gas of a non-condensable gas and a refrigerant gas, which has leaked into the refrigerator, is introduced into an airtight container provided with a cooling pipe, and is supplied from a small refrigerator separate from the refrigerator, In a bleeding device that strongly cools with a low temperature fluid flowing through a cooling pipe, and causes the refrigerant liquid in which the refrigerant gas is condensed to flow back to the evaporator of the refrigerator, the separate body so that the pressure in the closed container does not fall below a predetermined pressure. A means for controlling the operation of the small refrigerator is provided, and the pressure control mechanism in the bleeding device. 17. A pressure sensor for detecting the pressure in the airtight container, and a controller for opening and closing a drive power supply circuit of the small refrigerator based on a detection signal output of the pressure sensor. The pressure control mechanism in the extraction device according to claim 16, which is characterized in that. 18. The controller turns on the power supply circuit when the pressure detected by the pressure sensor becomes equal to or higher than a predetermined pressure P ₁ ,
The power supply circuit is turned off when the pressure becomes lower than a predetermined pressure P ₂ different from the above, the predetermined pressure P ₁ is -0.2 to +2.0 Kgf / cm ² g, and the predetermined pressure P is ₂ is characterized by a low value only 0.1~1.5Kgf / cm ² compared to the predetermined pressure P _1, the pressure control mechanism in the bleed system as set forth in claim 17. 19. A level sensor for detecting the liquid level of the refrigerant liquid in the hermetically sealed device is provided, and the controller turns off the power supply circuit when the detected value of the level sensor becomes a predetermined value or more. The pressure control mechanism in the extraction device according to claim 7 or 18, wherein the pressure control mechanism is configured to: 20. The controller is configured such that the level sensor detection value becomes lower than a predetermined value and the pressure sensor detection value becomes lower than a predetermined value after the power supply is turned off when the level sensor detection value becomes a predetermined value or more. When the pressure is equal to or higher than the predetermined pressure P ₁ , turn on the power circuit
20. The method according to claim 19, characterized in that
A pressure control mechanism in the extraction device described in.