JP2015114070A - Refrigerant exhaust device and refrigerant exhaust method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerant exhaust device that can suppress increase of combustible refrigerant concentration by vaporizing, in a short time, dissolved combustible refrigerant with respect to refrigeration oil that remains with a small amount inside a compressor after discharge of residual material and where combustible refrigerant is dissolved, and can ensure safety without an explosion risk of the compressor.SOLUTION: A vacuum pump 7 and a drive valve 4 are attached to a compressor 1 after discharge of residual material; pressure in the compressor 1 is decompressed; and after decompression for a prescribed time, the drive valve 4 is opened, ambient air is flowed into the compressor 1, and the pressure in the compressor 1 is restored to atmospheric pressure. By repeating the decompression and ambient air inflow, combustible refrigerant dissolved in refrigeration oil remaining with a small amount in the compressor 1 is vaporized in a short time to be exhausted.

Description

  The present invention relates to a refrigerant exhaust apparatus and a refrigerant exhaust method for exhausting an internal combustible refrigerant by a mechanism that depressurizes the inside of a compressor by a vacuum pump and a drive valve.

Several conventional methods for treating flammable refrigerants have been proposed. One is to collect the refrigeration oil and flammable refrigerant in the refrigeration cycle by sucking them into the separation tank when the refrigerator is disassembled, and after the collection, the flammable refrigerant is recovered. There is a method of diluting with air and releasing it to the atmosphere (for example, see Patent Document 1).
In addition, by using high-temperature superheated steam as a method for treating refrigeration oil and combustible refrigerant in the compressor, the inside of the compressor is washed away so that no residue remains in the compressor (see, for example, Patent Document 2).
Another method for recovering refrigerant from the outdoor unit of an air conditioner is to connect a low-pressure tank and a high-pressure tank, and recover the refrigerant by pushing out gas from the high-pressure tank and negative pressure suction from the low-pressure tank. (For example, refer to Patent Document 3).

Japanese Patent No. 4854302 JP2007-212056 JP 2002-147903 A

  In the processing method of the combustible refrigerant as shown in Patent Documents 1 to 3, when the refrigerating machine oil and the combustible refrigerant are discharged from the compressor, a small amount of the refrigerating machine oil in which the combustible refrigerant that could not be recovered is dissolved in the compressor. As a result, the combustible refrigerant dissolved from the refrigerating machine oil remaining in the compressor evaporates with time, and the compressor may explode due to an increase in the combustible refrigerant concentration in the compressor.

  The present invention has been made to solve the above-described problems. The compressor after discharging the refrigerating machine oil and the combustible refrigerant is treated with the combustible refrigerant dissolved in a short time, and the compressor. An object of the present invention is to propose a refrigerant exhaust device and a refrigerant exhaust method that can ensure safety without explosion hazard even during dismantling.

The refrigerant exhaust device of the present invention is provided between the compressor and the first vacuum hose connected to the refrigerant filling port of the compressor and the atmosphere, and selectively applies atmospheric pressure to the refrigerant filling port of the compressor. And a control device for controlling the drive valve and the vacuum pump via a second vacuum hose, and a control device for controlling the drive valve and the vacuum pump. The refrigerant remaining in the compressor is vaporized by controlling the opening and closing of the drive valve so that the reduced pressure state and the state in which the atmosphere is introduced are repeated in the compressor.
In the refrigerant exhaust method of the present invention, a vacuum pump is attached to the suction side of the compressor after discharging the residue, and a drive valve that opens and closes to the atmosphere is attached to a position different from the suction side of the compressor. The vacuum pump is operated to depressurize the inside of the compressor, depressurize for a certain period of time, and then repeat the operation of opening the drive valve and flowing in the atmosphere to generate bubbles and vaporize the combustible refrigerant. .

  According to the present invention, the concentration of the flammable refrigerant in the compressor is reduced by repeating the decompression and the inflow of air inside the compressor, evaporating the flammable refrigerant dissolved from the refrigeration oil remaining in the inside in a short time, and exhausting it. Can be prevented, explosion caused by the increase in the concentration of the flammable refrigerant can be prevented, and worker safety can be ensured.

It is a schematic block diagram which shows the principal part of the refrigerant | coolant exhaust apparatus by Embodiment 1 which concerns on this invention. It is a perspective view which shows the connection to the compressor by Embodiment 3 which concerns on this invention, and a part of refrigerant | coolant exhaust apparatus in a cross section. It is a pressure-dissolved oxygen amount diagram for demonstrating the effect | action in this invention.

Embodiment 1 FIG.
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram showing a main part of the refrigerant exhaust apparatus according to the first embodiment. FIG. 3 is a pressure-dissolved oxygen amount diagram for explaining the operation in the present invention.
The first vacuum hose 2 is connected to the refrigerant filling port 18 of the compressor 1 and is connected to the atmosphere via the pressure sensor 3 and the first drive valve 4. With respect to the compressor 1 after discharging the residue containing the refrigerating machine oil and the combustible refrigerant liquid, the second drive valve 6 is provided on the suction pipe 16 and discharge pipe 17 side of the compressor 1 by the second vacuum hose 5. Via the vacuum pump 7. The opening and closing of the first drive valve 4 can be controlled by the control device 8, and the air can be flowed into the compressor 1 being sucked by the vacuum pump 7 to return the pressure to atmospheric pressure.

  With such a configuration, the first and second vacuum hoses 2 and 5 are connected to the compressor 1 after discharging the residue. After confirming the connection, the vacuum pump 7 sucks the inside 1 of the compressor and depressurizes it. During decompression, the first drive valve 4 connected to the first vacuum hose 2 is sealed, and the second drive valve 6 connected to the second vacuum hose 5 is opened. The suction by the vacuum pump 7 is started under such a driving valve opening / closing condition, and the inside of the compressor 1 is decompressed.

After a certain period of time has passed, the air is taken into the compressor 1 while suction by the vacuum pump 7 is continued, and the reduced pressure is returned to near atmospheric pressure. The driving valve opening / closing condition at the time of inflow to the atmosphere is that both the first driving valve 4 connected to the first vacuum hose 2 and the second driving valve 6 connected to the second vacuum hose 5 are opened. After confirming that the atmosphere has flowed into the compressor 1 for a certain period of time and the pressure has returned to near atmospheric pressure, the opening and closing conditions of the driving valve are again set to the first driving valve 4 and the second driving valve 6 open, Return to the same conditions as the initial suction.
For example, at the time of suction by the vacuum pump 7, the second drive valve 6 is opened for 55 seconds to reduce the pressure in the compressor 1. After 55 seconds, the first drive valve 4 is opened for 5 seconds to take in the atmosphere, and the pressure in the compressor 1 is returned to near atmospheric pressure. This operation is defined as one cycle, and this cycle motion is repeated an arbitrary number of times.

With this configuration, the change in solubility in a liquid in a reduced pressure state is utilized. That is, the amount of gas that can be dissolved in the liquid by reducing the pressure from the atmospheric pressure decreases from the atmospheric pressure state, and the saturated gas changes into bubbles in the liquid.
For example, at atmospheric pressure (101 kPa), 0.07 g of oxygen is dissolved in 1 L of water at 0 ° C. When the pressure is reduced from the atmospheric pressure state, the dissolved amount of oxygen decreases as shown in FIG. When the pressure is reduced from atmospheric pressure to 10 kPa, oxygen dissolved in water becomes 10% at atmospheric pressure, and 90% of saturated oxygen changes to gas.

  Thus, by reducing the pressure in the compressor 1 from the atmospheric pressure to 10 kPa with the vacuum pump 7, oxygen, nitrogen, etc. dissolved from the refrigerating machine oil remaining in the compressor 1 are generated as bubbles due to the pressure drop. The same effect as bubbling is obtained by the generated bubbles, and the dissolved combustible refrigerant is absorbed by the bubbles, and the combustible refrigerant can be degassed and evaporated from the refrigerating machine oil. Moreover, the raise of the combustible refrigerant | coolant density | concentration in the compressor 1 can be suppressed by exhausting the combustible refrigerant | coolant which vaporized.

  If the pressure in the compressor 1 is continuously reduced, oxygen and nitrogen dissolved in the refrigerating machine oil are reduced, so that the generated bubbles are reduced and the combustible refrigerant cannot be degassed. Therefore, the air is dissolved into the refrigeration oil by flowing the air into the compressor 1. By flowing the air into the decompressed compressor for 5 seconds, the frozen air oil is agitated by a sudden pressure change, and some of oxygen, nitrogen, etc. contained in the air can be dissolved. After the inflow to the atmosphere, the inside of the compressor 1 is decompressed again, so that a part of the atmosphere dissolved in the refrigerating machine oil becomes bubbles again, and the flammable refrigerant can be further degassed by the bubbling effect. This operation makes it possible to vaporize the combustible refrigerant dissolved in a shorter time than when the vacuum pump 7 continues to suck.

As described above, when the inside 1 of the compressor is sucked by the vacuum pump 7, the opening and closing of the first drive valve 4 is controlled, and the inside of the compressor is repeatedly decompressed and introduced into the atmosphere, so that it cannot be vaporized from the refrigerating machine oil by one decompression. Even if the flammable refrigerant remains, the flammable refrigerant dissolved can be gradually vaporized by flowing in the atmosphere, returning the pressure in the refrigeration oil, and reducing the pressure again, and more flammable than just reducing the pressure by the vacuum pump 7. Can be vaporized. By sucking and exhausting the vaporized combustible refrigerant, the concentration of the combustible refrigerant can be reduced to a concentration at which there is no risk of explosion in a shorter time than when the pressure is continuously reduced by the vacuum pump 7. According to the method of changing the pressure in the compressor 1 by the vacuum pump 7 and the air inflow in the present invention, there is no upper limit to the number of pressure fluctuations, and the pressure in the compressor 1 is changed any number of times to dissolve from the remaining refrigeration oil. A combustible refrigerant can be vaporized.
Furthermore, it is possible to prevent an explosion due to an increase in the concentration of the flammable refrigerant with respect to the compressor after the residue treatment, and it is possible to ensure the safety of the operator.

Embodiment 2. FIG.
A second embodiment according to the present invention will be described with reference to FIG. 1 similar to the first embodiment described above.
In the first embodiment, after the pressure in the compressor 1 is reduced by the suction cycle of the vacuum pump 7 and the second drive valve 6, the first drive valve 4 is opened, the atmosphere is introduced, and the pressure reduction is started again. However, in the second embodiment, after the end of one cycle, the second drive valve 6 is controlled before the decompression is started again, and after a certain period of time is closed, the work process is opened.
Although the second drive valve 6 is sealed for a certain period of time after the first drive valve 4 is opened, the timing for sealing the second drive valve 6 is the same as the opening of the first drive valve 4 due to atmospheric inflow. It may be at the same time or after a while.

For example, after the atmosphere flows into the compressor 1 for 5 seconds, the second drive valve 6 is sealed for 5 seconds, and then the suction in the compressor 1 is started. At this time, the pressure in the compressor 1 is completely returned to the atmospheric pressure by sealing the second drive valve 6 before starting the suction in the compressor 1. Therefore, the pressure in the compressor 1 becomes larger than that in the first embodiment, and more bubbles are generated in the refrigeration oil when the refrigeration oil is decompressed again. By increasing the number of generated bubbles, more combustible refrigerant can be vaporized.
According to this configuration, by adding the opening / closing conditions of the second drive valve 6, the pressure in the compressor 1 is returned to atmospheric pressure and the pressure is reduced, so that more bubbles are generated in the refrigerating machine oil and the flammable refrigerant dissolved is further vaporized. Effect can be obtained. By repeating depressurization and air inflow, the combustible refrigerant can be vaporized more than in the first embodiment, and the increase in the combustible refrigerant concentration can be suppressed.

Embodiment 3 FIG.
A third embodiment of the present invention will be described with reference to FIG. FIG. 2 is a perspective view showing a section of the connection to the compressor and a part of the refrigerant exhaust device according to the third embodiment.
In the example shown in FIG. 1, the compressor 1 is connected to the vacuum pump 7 via the second drive valve 6, but by changing the pipe length and adding the number of pipes as shown in FIG. The number of compressors 1 to be sucked can be increased. For example, in FIG. 2, the piping connected from the vacuum pump 7 is changed, and the number of connecting piping is increased so that a plurality of compressors 1 can be sucked. Further, the vacuum pump 7 and the surroundings of the piping are covered as suction places of the compressor 1 to be connected, and the suction places of the plurality of compressors 1 are secured by installing the loading table of the compressor 1 on those devices. Yes. Further, vacuum hoses 2 and 5 connected to the compressor 1 are respectively installed from the loading platform, and the pressure sensor 3 and the first drive valve 4 are installed in the first vacuum hose 2 in the apparatus as in the first embodiment. Prepare and connect each. It is possible to control the sealing and opening of all the first drive valves 4 to allow the atmosphere to flow into the compressor 1 during suction.

The second vacuum hose 5 is connected to the second drive valve 6 by piping in the apparatus. Similar to the first drive valve 4, the same number as the compressors 1 to be connected is installed, and the sealing and opening of all the second drive valves 6 are controlled. Further, a plurality of joint pipes 14 are joined from the second drive valve 6 and connected to the vacuum pump 7. An oil separator 13 may be installed near the suction port of the vacuum pump 7 in order to prevent refrigeration oil from entering the vacuum pump 7 during suction. Further, the vacuum pump 7 and the blower 12 for discharging the sucked air to the outside of the apparatus are connected.
With the above configuration, a plurality of compressors 1 can be sucked at the same time, and a plurality of compressors 1 connected to the refrigerant exhaust device by repeatedly depressurizing and flowing into the atmosphere in the compressor 1 as in the first and second embodiments. The combustible refrigerant dissolved from the refrigerating machine oil remaining in a small amount in the compressor 1 can be vaporized, and the same effect as that in the suction of the first and second embodiments can be obtained, and the vaporized combustible refrigerant is removed from the apparatus. Can be sucked and exhausted. Therefore, the combustible refrigerant concentration in the compressor 1 does not increase, and safety can be ensured without the danger of the compressor exploding. Moreover, the improvement effect of the processing capacity by the refrigerant exhaust device can be obtained by simultaneously sucking a plurality of compressors.

Embodiment 4 FIG.
The fourth embodiment according to the present invention will be described with reference to FIG. 2 similar to the third embodiment described above.
In the third embodiment, all the compressors 1 are connected to the apparatus at the time of suction by the compressor 1 and then sucked at the same time. However, the compressors 1 are connected to the refrigerant exhaust device one by one and sucked individually. You may start. The operation panel 11 is provided with an activation switch 10 for starting suction of the compressors 1a, 1b,.
For example, the first compressor 1a is installed on the loading table using the apparatus shown in FIG. After connecting the vacuum hoses 2 and 5, after depressing the start switch 10 at the location where the suction is to be started and starting the suction, the second compressor 1b is installed in the refrigerant exhaust device and the vacuum hoses 2 and 5 are connected. Press the start switch 10. However, when suction is started for the second compressor 1b, the first and second drive valves 4 and 6 are sealed and sucked until one cycle of suction and air inflow of the first compressor 1a is completed. Is not started immediately and is set in a standby state. After the suction of the first compressor 1a that has started the suction for one cycle, the suction of the next cycle is started, and at the same time, the driving valve 6 of the compressor 1b connected to the second is opened to open the second compressor Start the suction of 1b.

  The number of connected compressors 1 is increased by the same method, and the compressor can be continuously sucked by time difference. Even when the suction method of the compressor 1 in this apparatus is sucked at a time difference of one by one, the suction by the vacuum pump 7 and the drive valves 4 and 6 and the air inflow are repeated as in the first and second embodiments. The combustible refrigerant can be vaporized and recovered in a short time from the refrigeration oil in which the small amount of the combustible refrigerant remaining in the machine 1 is dissolved. In addition, by forcibly evaporating the dissolved flammable refrigerant in a short time, the flammable refrigerant in the compressor 1 will not rise, so there is no danger of the compressor explosion and ensuring the safety of the operator. Can do. Further, it is not necessary to wait until all the compressors 1 connected to the apparatus are connected as in the third embodiment, and processing can be performed immediately upon connection to the apparatus, so that the entire work time can be shortened compared to the third embodiment. In addition, the effect of improving the processing capacity by the refrigerant exhaust device can be obtained.

  The number of connected compressors 1 is increased by the same method, and the compressor can be continuously sucked by time difference. Even when the suction method of the compressor 1 in this apparatus is sucked at a time difference of one by one, the suction by the vacuum pump 7 and the drive valves 4 and 6 and the air inflow are repeated as in the first and second embodiments. The combustible refrigerant can be vaporized and recovered in a short time from the refrigeration oil in which the small amount of the combustible refrigerant remaining in the machine 1 is dissolved. In addition, by forcibly evaporating the dissolved flammable refrigerant in a short time, the flammable refrigerant in the compressor 1 will not rise, so there is no danger of the compressor explosion and ensuring the safety of the operator. Can do. Further, it is not necessary to wait until all the compressors 1 connected to the apparatus are connected as in the third embodiment, and processing can be performed immediately upon connection to the apparatus, so that the entire work time can be shortened compared to the third embodiment. In addition, the effect of improving the processing capacity by the refrigerant exhaust device can be obtained.

  It should be noted that within the scope of the present invention, a part or all of each embodiment can be freely combined, or each embodiment can be appropriately modified or omitted.

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 1st vacuum hose, 3 Pressure sensor, 4 1st drive valve, 5 2nd vacuum hose, 6 2nd drive valve, 7 Vacuum pump, 8 Control apparatus, 9 Refrigerant exhaust apparatus, 10 Start switch, 11 Operation panel, 12 Blower, 13 Oil separator, 14 Joint piping, 15 Exhaust port, 16 Suction tube, 17 Discharge tube, 18 Refrigerant filling port.

Claims (9)

  A compressor, a drive valve provided between the first vacuum hose connected to the refrigerant charging port of the compressor and the atmosphere and capable of selectively applying atmospheric pressure to the refrigerant charging port of the compressor; A vacuum pump connected to a suction pipe and a discharge pipe of the compressor via a vacuum hose of the compressor, a control device for controlling the drive valve and the vacuum pump, and controlling the opening and closing of the drive valve by the control device. Accordingly, the refrigerant exhaust device configured to vaporize the refrigerant remaining in the compressor by repeating the reduced pressure state and the state of introducing the atmosphere in the compressor.   A first drive valve provided between the compressor and a first vacuum hose connected to the refrigerant filling port of the compressor and the atmosphere and capable of selectively applying atmospheric pressure to the refrigerant filling port of the compressor A second drive valve provided in the second vacuum hose, and a vacuum pump connected to the suction pipe and the discharge pipe of the compressor via the second vacuum hose provided with the second drive valve A control device for controlling the first drive valve, the second drive valve and the vacuum pump, and controlling the opening and closing of the first drive valve and the second drive valve by the control device, A refrigerant exhaust device configured to vaporize the refrigerant remaining in the compressor by repeating a reduced pressure state and a state in which air is introduced in the compressor.   After the first drive valve is closed and the second drive valve is opened, the vacuum pump is sucked and the pressure in the compressor is reduced, and then the first drive valve is opened. The refrigerant exhaust device according to claim 2, wherein the air is introduced into the compressor.   After the first driving valve is opened and the atmosphere is introduced into the compressor, the pressure in the compressor is further increased by closing the second driving valve for a predetermined time before starting decompression again. The refrigerant exhaust device according to claim 3, wherein the refrigerant exhaust device is close to atmospheric pressure.   A plurality of the compressors are provided, and the plurality of compressors are collectively connected to the first and second vacuum hoses via connection pipes, and at the same time, the plurality of compressors are simultaneously connected to the atmosphere by the driving valve. The refrigerant exhaust apparatus according to claim 1 or 2, wherein the refrigerant exhaust apparatus is configured to introduce the refrigerant.   A plurality of the compressors, a plurality of the driving valves corresponding to each of the compressors, and a compressor that introduces the atmosphere among the plurality of the compressors by selectively controlling the driving valves. The refrigerant exhaust device according to claim 1 or 2, wherein the refrigerant exhaust device is selected.   A vacuum pump is attached to the suction side of the compressor after the residue is discharged, and a drive valve that opens and closes to the atmosphere is attached to a position different from the suction side of the compressor, and the vacuum pump is operated to perform the compression. A refrigerant exhausting method characterized in that after the pressure inside the apparatus is reduced and the pressure is reduced for a certain period of time, air bubbles are generated by repeating the operation of opening the drive valve and allowing the atmosphere to flow, thereby vaporizing the combustible refrigerant.   By sucking the inside of the compressor in which a small amount of refrigerating machine oil remains with a vacuum pump, the inside of the compressor is decompressed, bubbles are generated in the remaining refrigerating machine oil, and the combustible refrigerant dissolved by bubbling is degassed and the compression is performed. Opening the drive valve that introduces the atmosphere during decompression in the machine causes the atmosphere to dissolve in the refrigerating machine oil in which dissolved oxygen and nitrogen are reduced, and then decompresses again to generate bubbles and vaporize the flammable refrigerant. A refrigerant exhaust method characterized by that.   The refrigerant exhausting method according to claim 8, wherein the combustible refrigerant is vaporized by repeating the pressure reduction by the operation of the vacuum pump and the introduction of the atmosphere by opening the drive valve.

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