JPH062994A - Method and apparatus for adjusting temperature and pressure for recovery of refrigerant - Google Patents

Abstract

PURPOSE:To prevent a refrigerant gas from being diffused to an atmosphere even when outside temperature is high or a refrigerant liquid temperature filled in a portable can is high by improving a technique for sucking and discharging a refrigerant sealed in a refrigerator by a compressor (or vacuum pump) and recovering it as the refrigerant liquid in the portable can by a filling pipe through a condenser and a gas-liquid separator. CONSTITUTION:A filling pipe 8 and a vaporizing pipe 9 are passed through the cover 7a of a portable can 7. The other end of the vaporizing pipe 9 is connected to the intake side of a compressor 2. The pressure of the vaporizing pipe is detected by a pressure sensor 11 and the temperature of a refrigerant liquid in a portable can is detected by a temperature sensor 12. A solenoid valve 14 interposed and connected to the middle of the vaporizing pipe 9 is so controlled as to be opened and closed by a control circuit 13 to which these detecting signals are input. An air sealed in the portable can 7 is sucked and discharged by a compressor 2 and discharged from a discharge valve 4b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when the refrigerant enclosed in a refrigerator is transferred to a refrigerant container outside the machine and recovered, controls the temperature and pressure in the recovery system to smoothly carry out the recovery work. The present invention relates to an apparatus and a method for preventing the refrigerant gas from being released into the atmosphere.

[0002]

2. Description of the Related Art Refrigerators are used as a refrigerant material (for example, Freon R1).
1) is sealed and sealed, and 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 fluid is drawn from the refrigeration system of the refrigerator and collected in the refrigerant tank. After being temporarily stored, and after completing inspection and maintenance, the refrigerant fluid in the refrigerant tank is returned to the refrigerator. FIG. 4 is a system diagram showing a conventional recovery device, in which the refrigerator 1 comprises a condenser 1a, an evaporator 1b, and a compressor 1c to constitute a refrigeration system, and a refrigerant (for example, CFC / R11) is sealed and hermetically sealed. is doing. After the refrigerant liquid is transferred from the above refrigerant system to the refrigerant tank or the like, the refrigerant gas remaining in the refrigerant system is transferred to the refrigerant tank 5, so that the refrigerant gas in the refrigerant machine 1 is sucked and pumped by the compressor 2. The condenser 3 is cooled to liquefy the refrigerant gas. For example, when a low-pressure chlorofluorocarbon such as chlorofluorocarbon R11 is used as the refrigerant, a non-condensable gas such as air is mixed in the refrigerator 1, and the air contains some water vapor. A fluid such as a refrigerant cooled by the condenser 3 is guided to a gas-liquid separator 4 so that only a liquid component is float valve 4a.
Is collected in the refrigerant tank 5 and the gas component is discharged into the atmosphere through the discharge valve 4b. Reference numeral w is a viewing window for observing the amount of water accumulated, 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. For this reason, the refrigerant was recovered as in the conventional example shown in FIG. 4, but as far as this idea is concerned, efforts are made to thoroughly collect the refrigerant even at a higher cost than the refrigerant to be recovered. Was not done.

In the 1940s, various kinds of pollution became social problems, and in the 1960s, the global environmental problem of ozone layer depletion caused by refrigerants and solvents such as CFCs was discussed internationally. It has become an era in which even one drop of CFC must not be dissipated into the atmosphere even if it costs more than the monetary value of the recovered CFC. From this point of view, when the prior art of FIG. 4 is viewed, even if the compressor 2 discharges the refrigerant gas in the refrigerator 1 to the maximum, the gas pressure inside the machine 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 750.
A technique using a vacuum pump 9 as shown in FIG. 5 to reduce the pressure to mmHg is also known.

[0005]

In the prior art of FIGS. 4 and 5, the non-condensable gas discharged from the discharge valve 4b contains the refrigerant gas, and the mixed gas of the non-condensable gas and the refrigerant gas. With respect to the problem that the gas is diffused into the atmosphere, a technique of completely rectifying the refrigerant gas by rectifying the mixed gas accumulated in the upper space of the gas-liquid separator 4 without directly discharging it from the discharge valve 4b. Has been recently developed and is achieving significant results. However, the work of recovering the refrigerant in the refrigerator 1 has the following problems.
The capacity of the refrigerator 1 is, for example, 300 refrigeration tons (1 refrigeration ton =
In the case of 3024 kcal / hour), about 500 kg of refrigerant is stored. Therefore, the refrigerant tank 5 shown in FIGS. 4 and 5 requires a capacity of 500 kilograms. However, there are many cases where the refrigerator installed before the pollution of CFCs becomes a social problem is not provided with this refrigerant tank 5, and the injection pipe 8 is connected to the bottom of the gas-liquid separator 4 as shown in FIG. Then, the refrigerant liquid is transferred to the portable can 7. This portable can was used to supply the refrigerant from the refrigerant manufacturer to the refrigerator installation site. For example, when the refrigerant is R-11, the capacity is 100 kilograms or 50 kilograms, and it is placed near the refrigerator. It has been done. As shown in FIG. 7A, when the tip of the injection pipe 8 is inserted into the mouth of the portable can 7 and the refrigerant liquid is injected,
When the temperature of the injected refrigerant liquid is higher than the boiling point corresponding to the atmospheric pressure, a part of the refrigerant liquid evaporates until the temperature of the refrigerant liquid drops to the boiling point, and the evaporated refrigerant gas is in the atmosphere as indicated by arrow a. Will be dissipated. Also, when the ambient temperature of the portable can is higher than the boiling point of the refrigerant and the temperature of the portable can is also higher than the boiling point of the refrigerant, a part of the refrigerant liquid evaporates and is diffused into the atmosphere. . As shown in FIG. 7 (B), the lid 7 is provided to prevent the above refrigerant gas from being diffused (arrow a).
When a is provided, there is no escape area for the air trapped in the portable can 7, so that the injection of the refrigerant liquid is blocked.
In addition, when the temperature is higher than the boiling point of the refrigerant, or when the temperature of the injected refrigerant liquid is high, the pressure inside the portable can becomes atmospheric pressure or higher, so a portable device without a separate cooling means is provided. It is inappropriate to inject the refrigerant liquid into the can 7. The present invention has been made in view of the above circumstances, even when the outside air temperature is higher than the boiling point of the refrigerant, or even when the refrigerant liquid temperature flowing in is above the boiling point An object is to provide a simple and inexpensive device for adjusting the temperature and pressure so that the refrigerant liquid can be collected in a portable can without leaking the gas into the atmosphere, and a method for adjusting the temperature and pressure. To do.

[0006]

The basic principle of the present invention created to achieve the above objects will be briefly described with reference to FIG. 1 corresponding to the embodiment. A lid that fits a portable can 7 will be described. 7a is provided, and a refrigerant injection pipe 8 and a vaporization pipe 9 that also functions as an air vent pipe in the can are penetrated through the lid 7a, and the other end of the vaporization pipe 9 is on the suction side of the compressor 2. Communicate with. Then, the temperature of the refrigerant liquid is detected by the temperature sensor 12, and the pressure inside the vaporizing pipe is detected by the pressure sensor 11. Further, a control circuit 13 for opening and closing the solenoid valve 14 based on these detection signals is provided.

[0007]

According to the above-mentioned means, the air in the portable can 7 can be sucked into the compressor 2 by the vaporization pipe 9 and discharged, so that the refrigerant liquid can be smoothly injected from the injection pipe 8. Further, when the refrigerant in the portable can 7 is evaporated, the heat of vaporization is removed, so that the refrigerant liquid in the can is cooled. In addition, the pressure sensor 11
When the pressure detected by is approaching the pressure limit of the portable can, the solenoid valve 14 is opened and also functions as a safety valve.

[0008]

FIG. 1 shows an embodiment of the present invention, in which the present invention is applied to the conventional recovery device shown in FIG. The injection pipe 8, the stop valve 15, and the vaporization pipe 9 are hermetically penetrated through the lid 7a that fits the portable can 7. This vaporization pipe is an abbreviation for an exhaust and vaporization pipe, and is used for the compressor 2
The stop valve 10 and the solenoid valve 14 are provided in the middle of the connection. Then, the pressure sensor 11 detects the pressure in the vaporization pipe, the temperature sensor 12 detects the temperature of the refrigerant liquid, and these detection signals are input to the control circuit 13, and the control circuit controls the opening / closing of the solenoid valve 14. To do. The temperature sensor 12 of this example is constituted by a normally open type temperature sensitive switch that closes at 20 ° C. or higher, and the pressure sensor 11 has a pressure of 1 kgf / c.
It is composed of a pressure sensitive switch that is closed at m ² G or more, and the control circuit 13 of this example is structured as shown in FIG. That is, the temperature sensitive switch 12 and the pressure sensitive switch 11 are connected in parallel, and when the temperature rises above 20 ° C. or the pressure exceeds 1 kgf / cm ² G, the solenoid valve 14 is energized to open the solenoid coil. The valve operates. As can be easily understood from FIG. 1, the discharge pressure of the compressor 2 is applied to the gas-liquid separator 4 via the condenser 3 and reaches the portable can 7 via the injection pipe 8. For this reason, when the refrigerant liquid starts to be injected into the portable can, the air trapped in the upper space inside the can rises in pressure, and the pressure sensor 11 detects the pressure increase and opens the solenoid valve 14. As a result, the air in the portable can is sucked into the compressor 2 through the vaporization tube 9, and the pressure inside the portable can is reduced so that the injection of the refrigerant liquid is not hindered. Further, as another effect of this action, there is no fear that the pressure in the portable can 7 will exceed the pressure limit of the portable can.

Further, when the temperature sensitive switch 12 constituting the temperature sensor 12 is closed when the outside air temperature is high or the temperature of the refrigerant liquid in the portable can is high, the electromagnetic valve 14 is opened and the inside of the portable can 7 is negative. A pressure is generated, and a part of the refrigerant liquid in the can vaporizes to take heat of vaporization, lowering the temperature inside the can. When carrying out the present invention, the temperature-pressure relationship is controlled so that the temperature T detected by the temperature sensor 12 does not become higher than the boiling point of the refrigerant corresponding to the atmospheric pressure. FIG. 3 shows an embodiment different from the above, and the present invention is applied to the conventional example of FIG. The basic configuration is similar to that of the embodiment shown in FIG. 1, but the vacuum pump 6 generally has a low discharge pressure, so that the pressure sensor 11 is 0.1
Consists of a pressure sensitive switch that closes at kgf / cm ² G or higher. In the case of this example, it is not necessary to take into account that the pressure inside the portable can reaches the pressure limit, so the pressure sensor 1
The purpose of installation of No. 1 is exclusively to detect "a state in which the air in the portable can 7 is trapped and the injection of the refrigerant liquid is blocked". In this example (FIG. 3) as well, as in the previous example, the temperature of the refrigerant liquid in the portable can must be kept below the boiling point. In both the present example and the previous example, while the refrigerant liquid is being injected into the portable can 7, it may be controlled so that the vapor pressure of the refrigerant at the can internal temperature <the can internal pressure. After filling with liquid, pressure sensor 1
Regardless of the detected pressure of No. 1, it is necessary to adjust the temperature so that the vapor pressure of the refrigerant at the temperature detected by the temperature sensor 12 is below atmospheric pressure, that is, below the boiling point at atmospheric pressure at that time. Otherwise, the lid 7a of the device of the present invention
When the is removed, the refrigerant liquid in the can may boil (as when removing the beer bottle lid).

The temperature sensor 12 is a portable can 7
To the side of. This mounting point must be below the level of the refrigerant liquid. The mounting method can be selected arbitrarily. For example, it may be attached by pressing with an adhesive tape, but in this example, a magnet (not shown) is attached so that the magnetic force is attracted to the portable can. .
This structure is convenient because the mounting / removing operation can be performed quickly and easily.

Further, the temperature sensor 1 shown in phantom in FIG.
It is also possible to attach the temperature sensor near the lower end of the injection pipe 8 as in 2 '. In this case, the temperature sensor 12 '
The signal electric wire 12a makes the lid 7a penetrate airtightly. With this structure, the temperature sensor 12 'comes into direct contact with the refrigerant liquid, so that there is no delay in sensing the temperature change.

[0012]

As described above with reference to the embodiments,
When the method of the present invention is carried out using the apparatus of the present invention, even when the outside air temperature is higher than the boiling point of the refrigerant, the refrigerant liquid is introduced into the portable can without leaking the refrigerant gas into the atmosphere. Can be collected.

[Brief description of drawings]

FIG. 1 is a system diagram showing one embodiment of a device of the present invention.

FIG. 2 is an explanatory diagram of a control circuit in the above embodiment.

FIG. 3 is a system diagram of an embodiment different from the above.

FIG. 4 is a system diagram showing a conventional example of a device for recovering a refrigerant enclosed in a refrigerator.

FIG. 5 is a system diagram of a conventional example different from the above.

FIG. 6 is a system diagram showing a conventional technique for collecting refrigerant in a portable can.

FIG. 7 is an explanatory diagram of a problem in the above conventional technique.

[Explanation of symbols]

1 ... Refrigerator, 1a ... Condenser, 1b ... Evaporator, 1c ... Compressor, 4 ... Gas-liquid separator, 4a ... Float valve, 4b ... Release valve, 5 ... Refrigerant tank, 6 ... Vacuum pump, 7 ... Portable Can, 7a ... Lid, 8 ... Injection pipe, 9 ... Vaporization pipe, 10 ... Stop valve, 11 ... Pressure sensor, 12, 12 '... Temperature sensor, 12a ... Signal wire, 13 ... Control circuit, 14 ... Solenoid valve, 15 … Stop valve.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeo Genba 1 Izumi-cho, Kanda, Chiyoda-ku, Tokyo Inside Hitachi Building Engineering Co., Ltd.

Claims (10)

[Claims] 1. A compressor (2) connected to a refrigerator, and a condenser (3) for liquefying a refrigerant gas by cooling a mixed gas of a refrigerant gas and a non-condensable gas discharged by the compressor. And a gas-liquid separator (4) for separating a gas-liquid mixed flow flowing out from the condenser, wherein a refrigerant liquid accumulated in a lower space of the gas-liquid separator (4) is stored. A lid (7a) that fits the portable can (7), a refrigerant liquid injection pipe (8) that penetrates through the lid and is airtightly attached, and is connected near the bottom of the gas-liquid separator (4); And a stop valve (15) inserted and connected to the injection pipe, a vaporization pipe (9) penetrating through the lid and airtightly attached, and connected to the suction side of the compressor (2), and A stop valve (10) inserted and connected to the vaporizing pipe, and the pressure in the vaporizing pipe. A pressure sensor for detecting (11), and wherein a temperature sensor for detecting the temperature of the refrigerant fluid in the portable valve can (7) (12), in the middle of the vaporizing tube (9), the stop valve (1
0) and a solenoid valve (14) which is located closer to the compressor (2) and is inserted and connected, and the output signal of the pressure sensor and the output signal of the temperature sensor are input to the solenoid valve (14). And a control circuit 13 for controlling the opening and closing of the refrigerant, the temperature and pressure adjusting device for recovering the refrigerant. 2. A vacuum pump (6) for sucking and discharging a refrigerant gas from the refrigerator, a condenser (3) for cooling and liquefying the refrigerant gas discharged from the vacuum pump, and a liquefaction by the condenser. In a refrigerant recovery device comprising a gas-liquid separator (4) for separating the non-condensable gas mixed with the refrigerant liquid from the collected refrigerant liquid, the gas is collected in a space below the gas-liquid separator (4). A lid (7a) suitable for a portable can (7) for containing a refrigerant liquid, and an injection of the refrigerant liquid which is fitted airtightly through the lid and is connected near the bottom of the gas-liquid separator (4). A pipe (8), a stop valve (15) inserted and connected to the injection pipe, and a vaporization pipe (which is attached to the suction side of the compressor (2) in an airtight manner by penetrating through the lid ( 9), and a stop valve inserted and connected to the vaporization pipe ( 10), a pressure sensor (11) for detecting the pressure in the vaporization pipe, a temperature sensor (12) for detecting the temperature of the refrigerant liquid in the portable valve can (7), and the middle of the vaporization pipe (9) The stop valve (1
0) and a solenoid valve (14) which is located closer to the compressor (2) and is inserted and connected, and the output signal of the pressure sensor and the output signal of the temperature sensor are input to the solenoid valve (14). And a control circuit 13 for controlling the opening and closing of the refrigerant, the temperature and pressure adjusting device for recovering the refrigerant. 3. The pressure sensor is a normally open pressure sensitive switch that closes at a predetermined pressure or higher, and the temperature sensor is a normally open temperature sensitive switch that closes at a predetermined temperature or higher. Both switches are connected in parallel with each other, the solenoid valve is a normally closed solenoid valve that opens when energized, and both switches are connected in the drive circuit of the solenoid valve. The temperature and pressure adjusting device for refrigerant recovery according to claim 1 or 2, characterized in that 4. The temperature and pressure control for refrigerant recovery according to claim 1 or 2, wherein the temperature sensor has a magnet means for adsorbing to the portable can. apparatus. 5. The temperature sensor is used by being put in the portable can, and the signal wire (12a) of the temperature sensor penetrates the lid (7a) in an airtight manner. The temperature / pressure adjusting device for recovering the refrigerant according to claim 1 or 2, characterized in that 6. The refrigerant gas remaining in the refrigerator after the liquid refrigerant sealed in the refrigerator (1) is collected together with the non-condensable gas leaking into the refrigerator. Is sucked by the compressor (2) and passed through the condenser (3) to form a gas-liquid mixed flow of the refrigerant liquid and the non-condensable gas, and the mixed flow is guided to the gas-liquid separator (4) to non-condensable. In the recovery operation of separating the gas into the atmosphere and releasing the refrigerant liquid into the lower space of the gas-liquid separator, when the refrigerant liquid accumulated in the gas-liquid separator is transferred to the portable can (7), The air contained in the portable can is sucked into the compressor (2) to be removed, and at the same time, a part of the refrigerant liquid in the portable can is vaporized and sucked into the compressor (2) to generate heat of vaporization. Refrigerant recovery temperature, characterized by depriving and lowering the temperature inside the portable can Pressure adjustment method. 7. A refrigerant gas in a refrigerator (1) is sucked out by a vacuum pump (6), cooled by a condenser (3) and liquefied,
In a refrigerant recovery method of separating a non-condensable gas from a refrigerant liquid by a gas-liquid separator (4) and collecting the refrigerant liquid at the bottom of the gas-liquid separator, the refrigerant liquid accumulated at the bottom is stored in a portable can (7). When transferring, the air contained in the portable can is sucked into the vacuum pump (6) to be removed, and a part of the refrigerant liquid in the portable can is vaporized and sucked into the compressor (2). A method for adjusting the temperature and pressure for recovering a refrigerant, which comprises removing the heat of vaporization to lower the temperature inside the portable can. 8. The temperature of the refrigerant liquid in the portable can is set to T
Wherein the atmospheric pressure is P and the operation of vaporizing a part of the refrigerant liquid is controlled so that the temperature T of the refrigerant liquid is equal to or lower than the boiling point of the refrigerant at the atmospheric pressure P. Item 6
Alternatively, the method for adjusting the temperature and pressure for recovering the refrigerant described in 7 above. 9. The control for controlling the temperature T to be equal to or lower than the boiling point of the refrigerant at the atmospheric pressure P is performed in a pipe line connecting the portable can (7) and the suction side of the compressor (2) or the vacuum pump (6). Refrigerant recovery according to claim 8, characterized in that the solenoid valve (14) connected by insertion is controlled to be opened and closed by a pressure sensor (11) and a temperature sensor (12) via a control circuit (13). Temperature and pressure control method. 10. The refrigerant liquid is transferred into a portable can, and after the refrigerant liquid in the portable can reaches a predetermined amount, a part of the refrigerant liquid in the can is vaporized to remove the heat of vaporization to leave the residual liquid. The temperature and pressure adjusting method for refrigerant recovery according to claim 6 or 7, wherein the temperature of the refrigerant liquid in the can is made lower than the boiling point by cooling the refrigerant liquid.