JPH06313673A - Liquefying apparatus - Google Patents

Abstract

PURPOSE:To shorten a recovery time by shortening, after a compressor is temporarily stopped, a time up to restart and applying to recovery of fluorocarbon. CONSTITUTION:The liquefying apparatus comprises a compressor 2, a condenser 3, and a check valve 5 provided at an intermediate position of a high pressure side passage 6 for connecting the compressor 2 to the condenser 3 to prevent backflow from the condenser 3 side to the compressor 2 side while the operation of the compressor 2 is stopped. The valve 5 is provided at a position near a discharge side of the compressor 2. When fluorocarbon is recovered and liquefied, the compressor 2 is alternately repeatedly turned ON, OFF for each predetermined time to be intermittently operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a liquefying device for liquefying a gas, which comprises a compressor and a condenser, and more particularly,
The present invention relates to a liquefaction device preferably used for collecting and liquefying CFCs filled as a refrigerant in an automobile air conditioner or the like.

[0002]

2. Description of the Related Art Conventionally, as this type of liquefying apparatus, one shown in FIG. 6 has been known. This is a compressor c that is connected to a container a in which the gas to be recovered is accommodated via a connector b, sucks the gas from the container a and compresses it, and the gas compressed by the compressor c. A condenser d for cooling and liquefying the liquid and a storage cylinder e for storing the liquid obtained in the condenser d are provided. The compressor c
For example, in the case of a piston type, as shown in FIG. 7, a cylinder f and a cylinder chamber g
A piston h for expanding / contracting the volume of the piston and a drive source (not shown) for operating the piston h are provided. A suction port i from the low pressure side and a discharge port j to the high pressure side communicate with the cylinder chamber g.
Is provided with a low pressure side valve k, and the discharge port j is provided with a high pressure side valve m. The compressor c is provided with the piston h on the side that expands the cylinder chamber g.
Is operated to open the low-pressure side valve k to suck gas, and the piston h is operated to reduce the cylinder chamber g to compress the gas, and the compressed gas is discharged from the high-pressure side valve m. It is supplied to the condenser d through the port j.

[0003]

However, in the above-mentioned conventional liquefying apparatus, when the driving is temporarily stopped, the high-pressure (for example, 7 kg / cm @ 2) gas on the discharge port j side flows backward, and the high-pressure side valve m Leaks into the cylinder chamber g,
The pressure corresponding to the differential pressure (5 Kg / cm2) from the low pressure (for example, 2 Kg / cm2) gas on the suction port i side is the piston h.
It will work extra. Therefore, when restarting immediately after a temporary stop, the above-mentioned pressure becomes a resistance and a start-up failure occurs. For example, in a conventional liquefaction device such as a refrigerator or a dehumidifier, when restarting, the inside of the cylinder chamber g is generally The pressurized gas leaks to the low pressure side from the gap between the piston h and the inner peripheral surface of the cylinder f, and waits for a predetermined time (usually 3 minutes or more) for the cylinder chamber g to equalize the pressure with the low pressure side. It is designed to be carried out (see the chain line in FIG. 4). For this reason, the time from the stop of operation to the restart may be wasted, which causes inconvenience when it is desired to start early.

The conventional liquefying apparatus described above is generally operated continuously. Particularly, the gas to be liquefied is chlorofluorocarbon, and the chlorofluorocarbon is recovered from the equipment filled with the refrigerant and liquefied. Therefore, when the above liquefaction device is used, the following inconvenience occurs when the above continuous operation is performed. That is, if suction is continuously performed by the compressor,
The pressure on the suction side of the compressor is reduced and the freon is cooled, which causes the disadvantages such as frost adhesion on the piping system and the reduction of recovery efficiency. Therefore, an intermittent operation is performed in which the operation is performed only for a time period such that the influence of frost adhesion does not become large, and then the operation is temporarily stopped, and by stopping the operation, the freon on the suction side is heated and pressured, and then restarted repeatedly. It is possible. However, in this case, if it is necessary to wait the elapse of the predetermined time for restarting each time the vehicle is temporarily stopped, the recovery time becomes longer as the frequency of intermittent operation increases.

The present invention has been made in view of the above circumstances, and an object thereof is to shorten the time until the compressor is restarted after the compressor is temporarily stopped.
In addition, it is possible to shorten the recovery time by applying it to the recovery of CFCs.

[0006]

In order to achieve the above object, the invention according to claim 1 provides a compressor for sucking and compressing gas, and a gas connected to the discharge side of the compressor and compressed. It is assumed to have a condenser that cools and liquefies.
Then, a backflow blocking means for blocking backflow from the condenser side to the compressor side is provided at an intermediate position between the compressor and the condenser while the operation of the compressor is stopped.

According to a second aspect of the present invention, in the first aspect of the invention, the backflow prevention means is provided at a position near the discharge side of the compressor.

According to a third aspect of the present invention, in the first aspect of the invention, the backflow prevention means is constituted by a one-way flow means that allows only one-way flow from the compressor to the condenser side.

Further, in the invention described in claim 4, in the invention described in claim 1, the compressor is turned on and off alternately at predetermined intervals to perform intermittent operation so as to suck gas intermittently. And

Further, the invention according to claim 5 is the invention according to claim 4.
In the invention described above, the gas is chlorofluorocarbon.

[0011]

With the above construction, in the invention according to claim 1,
Since a backflow blocking means for blocking backflow from the condenser side to the compressor side is interposed between the discharge side of the compressor and the condenser, the compressor is stopped when the operation of the compressor is stopped. In the case of, for example, a piston type, the high-pressure gas leaking from the high-pressure side discharge port to the cylinder chamber via the high-pressure side valve is limited to only the one remaining in the compressor side pipe from the above-mentioned backflow prevention means, and the above-mentioned backflow prevention means The amount of leakage is smaller than that without. For this reason, as the amount decreases, the time required for the cylinder chamber to equalize the pressure with the low pressure side is shortened, and early restart is possible.

According to the second aspect of the present invention, in addition to the operation of the first aspect, the backflow prevention means is provided in the vicinity of the discharge side of the compressor, and the backflow prevention means is in the vicinity of the discharge side of the compressor. The closer to, the smaller the amount of high pressure gas acting on the compressor. Therefore, the time required to equalize the pressure with the low pressure side is further shortened, and the time required for restarting is further shortened.

According to the third aspect of the invention, in addition to the operation of the first aspect, since the backflow prevention means is constituted by the one-way flow means, the high pressure side to the compressor side when the compressor is stopped. The backflow to is automatically shut off.

In addition, in the invention described in claim 4, in addition to the operation according to the invention described in claim 1, since intermittent operation is performed and operation stop is repeated, the time until restarting at each stop is shortened. As a result, the total required time can be greatly shortened.

Further, in the invention described in claim 5, in addition to the operation according to the invention described in claim 4, when the gas to be liquefied is freon, intermittent cooling is performed to suppress excessive cooling of freon. As a result, it is possible to prevent a reduction in the efficiency of CFC recovery due to frost adhesion and the like, and also to prevent an increase in the overall recovery time due to the time required to restart each time the operation is stopped during intermittent operation.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment in which the liquefying device of the present invention is applied to a chlorofluorocarbon recovery device for recovering and liquefying the chlorofluorocarbon filled in an air conditioner or a refrigerator of an automobile. In the figure, 1 is a container filled with CFCs to be collected, 2 is a compressor that sucks and compresses CFCs from this container, and 3 is a compressor that cools CFCs compressed by this compressor 2 and liquefies them. The condenser 4 is a storage cylinder for storing the chlorofluorocarbon liquefied in the condenser 3, and the reference numeral 5 is interposed in the first high-pressure side passage 6 connecting the discharge side of the compressor 2 and the condenser 3. It is a check valve as one-way circulation means which is one mode of the backflow prevention means.

The container 1 is a container filled with CFC as a refrigerant in, for example, a refrigerator or an air conditioner of an automobile, and the CFC recovery device recovers CFC from the container 1 when the automobile is disassembled. It is used for storing in the above-mentioned storage cylinder 4 or for refilling the container 1 after extracting the fluorocarbon.

The compressor 2 is of a piston type having a completely closed structure. As shown in detail in FIG. 2, this compressor 2 has a hermetic housing 8 opened only in the low pressure side passage 7, a cylinder 9 arranged in the hermetic housing 8, and a reciprocating motion in the cylinder 9. Then cylinder chamber 10
11 that expands and contracts the volume of the
And a drive source (not shown) for operating the. And
A downstream end of the suction port 12 is connected to the cylinder chamber 10 via a low pressure side valve 13, and an upstream end of the discharge port 14 is connected to the cylinder chamber 10 via a high pressure side valve 15.
The upstream end of the suction port 12 faces the internal space of the sealed housing 8 and is opened, and the downstream end of the discharge port 14 penetrates the sealed housing 8 and is connected to the upstream end of the high-pressure side passage 6. That is, it is configured as a low-pressure dome shape. Then, the compressor 2 has the piston 11
The expansion stroke closes the high-pressure side valve 15 and opens the low-pressure side valve 13 to suck the low-pressure (for example, 2 Kg / cm2) CFC in the closed housing 8, and the compression stroke closes the low-pressure side valve 13 to a predetermined pressure. (Eg 7
Freon compressed to Kg / cm2) is a high pressure side valve 1
5 to the high pressure side passage 6 through the discharge port 14.

Further, a connector 7a with an automatic shutoff valve is connected to the upstream end of the low pressure side passage 7, and this connector 7
The connector 1a on the side of the container 1 is connected to a. Further, the connector 7 is provided in the low pressure side passage 7.
A service valve 16 and an accumulator 17 are provided downstream from a, and the accumulator 1
When the flon sucked into the compressor 2 through the low pressure side pipe 7 contains a liquid state, it is brought into a vaporized state by 7. Reference numeral 18 in FIG. 1 denotes a low-pressure side pressure switch, which stops the operation when the pressure in the low-pressure side passage 7 between the service valve 16 and the accumulator 17 reaches a preset low pressure regulation value. Has become.

Further, an oil separator 19 is provided in the middle of the first high pressure side passage 6, and the lubricating oil in the compressor 2 together with the CFC discharged to the first high pressure side passage 6 by the oil separator 19. When the oil is discharged, the lubricating oil is separated from the freon and is circulated to the low pressure side pipe line 7. The check valve 5 is provided at a position between the oil separator 19 and the condenser 3 in the first high-pressure side passage 6, and the check valve 5 allows the CFC in the first high-pressure side passage 6 to flow. Is allowed only in the direction from the compressor 2 to the condenser 3, while the flow in the opposite direction is prohibited.

The second high pressure side passage 2 is provided at the bottom of the condenser 3.
0 is connected to the upstream end of the second high pressure side passage 20.
A service valve 21, a dryer 22 for removing water from the liquid flon, and a side glass 23 for observation are installed in the downstream of the device. A connector 20a with an automatic shutoff valve is connected to the downstream end of the second high pressure side passage 20, and the connector 20a is detachable from another connector 4b at the upstream end of the rubber hose 4a extending from the storage cylinder 4. It is designed to be connected to.

The condenser 3 and the service valve 21 are also provided.
A relief valve 24 and a high-pressure side pressure switch 25 are connected to the second high-pressure side passage 20 between and, and the relief valve 24 relieves when the internal pressure of the second high-pressure side passage 20 is equal to or higher than a set pressure value. Further, the high-pressure side pressure switch 25 temporarily stops the operation of the compressor 2 when the pressure in the second high-pressure side pipeline 20 becomes equal to or higher than the preset high-pressure side regulation value. ing. further,
A second relief valve 26 is also connected to the second high-pressure side passage 20 between the side glass 23 and the connector 20a so as to relieve when the internal pressure is equal to or higher than a set pressure value.

Further, the upstream end of the refilling passage 27 is connected to the second high pressure side passage 20 near the upstream side of the connector 20a which is the most downstream end of the system. The downstream end is connected to the low pressure side passage 7 near the downstream side of the other connector 7a which is the most upstream end of the system. An electromagnetic valve 28 that opens and closes the refilling passage 27 is provided in the middle of the refilling passage 27. By opening the electromagnetic valve 28, the fluorocarbon in the storage cylinder 4 is removed. The container 1 can be refilled via the connector 7a.

Next, a fluorocarbon recovery method using the fluorocarbon recovery device having the above structure will be described.

First, the electromagnetic valve 28 is closed,
The connector 7a at the most upstream end is connected to the connector 1a of the container 1, and the connector 20a at the most downstream end is connected to the connector 4b on the storage cylinder 4 side. Next, the compressor 2 and the like are driven.

Due to the expansion stroke of the piston 11 of the compressor 2, the freon in the container 1 is sucked into the closed housing 8 of the compressor 2 through the low pressure side passage 7, and the cylinder chamber 10 is also passed through the suction port 12. Inhaled into.
Then, due to the compression stroke of the piston 11, the chlorofluorocarbon in the cylinder chamber 10 at a predetermined low pressure (for example, 2 Kg / cm2) is compressed to a predetermined pressure (for example, 7 Kg / cm2), and is passed through the discharge port 14 in this compressed state. First
It is discharged to the high pressure side passage 6. Then, the compressed Freon is supplied to the condenser 3 via the oil separator 19 and the check valve 5, and is cooled and liquefied by the condenser 3. The liquefied chlorofluorocarbon is stored in the storage cylinder 4 via the second high pressure side passage 20 and the rubber hose 4a.

After the operation for a predetermined time, the temporary operation is stopped and the pushing operation of the piston 11 to the discharge port 14 side is stopped. As a result, the high pressure CFC in the first high pressure side passage 6 from the check valve 5 to the high pressure side valve 15 and the discharge port 14 leaks from the high pressure side valve 15 and the pressure difference between the low pressure side pressure and the cylinder chamber 10 is reduced. Minutes, ie
5 kg obtained by subtracting 2 kg / cm2 from the above 7 kg / cm2
The amount corresponding to / cm2 will be reversed. And
This extra internal pressure acts on the piston 11 in the cylinder chamber 10, leaks from the piston ring portion into the closed housing 8 on the low pressure side, and equalizes the pressure on the low pressure side. At this time, the amount of high pressure side CFCs leaking to the cylinder chamber 10 is determined by the check valve 5
Is restricted to the upstream side, and the downstream side of the check valve 5 prohibits the reverse flow by the check valve 5. Therefore, compared with the case where the check valve 5 is not provided, Therefore, it is possible to shorten the time required to leak from the piston ring portion and equalize the pressure with the low pressure side. For example, FIG. 3 shows a test result regarding the relationship between the pressure difference acting on the cylinder chamber 10 due to the backflow of the high pressure side CFC and the pressure leakage time until the pressure difference equalizes with the low pressure side. In the figure, the differential pressure is 15 kg / cm.
2 seconds (see circle in the figure), 10 kg / cm2 (see x in the figure) and 8 kg / cm2 (see triangle in the figure), 20 seconds or less It becomes possible to restart by equalizing the pressure with the low pressure side in time. On the other hand, in the case of the conventional device without the check valve 5, as shown by the chain double-dashed line in FIG. 4, it takes a little less than 1 minute to a little more than 2 minutes, and the check valve 5 is provided. As a result, it is possible to significantly reduce the time required to restart.

Then, as shown in FIG. 5, after the suspension for a predetermined period of time, the system is restarted, operated for a predetermined period of time, and temporarily stopped to perform an intermittent operation. That is, after 1 minute of operation, the operation is repeated after stopping for 1 minute or less. According to this, about 60% of the CFCs are recovered by the first operation, and thereafter, as the CFC recovery progresses and the amount of CFCs remaining decreases,
The downtime is shortened. The operating time is set to a time within a range in which recovery efficiency does not decrease due to frost adhesion due to the inhalation of freon, and the stop time is set to a time at which the frost adhesion is eliminated by pressurization due to stop, and the remaining flon remains. The smaller the amount, the shorter the time for eliminating the frost adhesion. Therefore, the stop time is gradually shortened to shorten the entire collection time. Then, the stop time is finally set to the shortest time (for example, 20 seconds or less) necessary for restarting.

The present invention is not limited to the above embodiments, but includes various other modifications. That is, in the above-described embodiment, the liquefaction device is described as an example of the chlorofluorocarbon recovery device, but the liquefaction device is not limited to this, and a liquefaction device including a combination of a compressor and a condenser may be used in other devices. Can be applied.

In the above embodiment, the check valve 5 which is a one-way flow means is used as the backflow prevention means, but the invention is not limited to this, and an on-off valve is provided as the backflow prevention means, and this on-off valve is closed when the operation is stopped. The state may be changed to the open state when the internal pressure of the cylinder chamber is compressed until the internal pressure becomes equal to the high pressure side at the time of restart.

Further, in the above embodiment, the piston type is used as the compressor 2, but the present invention is not limited to this, and other types such as a rotary type, a scroll type or a screw type may be used. Also in this case, the resistance at the time of restart can be removed early to shorten the time until restart.

Further, in the above embodiment, the check valve 5 is provided between the oil separator 19 and the condenser 3 in the high pressure side passage, but the present invention is not limited to this, and the oil separator 1 is not limited to this.
It may be provided between the compressor 9 and the compressor 9. In this case, compressor 2
Since the volume in the high pressure side passage 6 between the high pressure side valve 15 and the high pressure side valve 15 becomes smaller, the time until the cylinder chamber 10 is pressure-equalized can be further shortened, and the time until the restart time can be further shortened. Can be achieved.

[0034]

As described above, according to the chlorofluorocarbon recovery device in the first aspect of the invention, the reverse flow from the condenser side to the compressor side is prevented between the discharge side of the compressor and the condenser. Since the backflow prevention means is interposed, when the operation of the compressor is stopped, if the compressor is, for example, a piston type,
It is possible to limit the high pressure gas leaking from the high pressure side discharge port to the cylinder chamber through the high pressure side valve to only the gas remaining in the pipe on the compressor side of the backflow prevention means, and in the case without the above backflow prevention means. In comparison, the amount of leakage can be reduced. Therefore, the time until the cylinder chamber is pressure-equalized with the low pressure side can be shortened by the decrease, and the time required for restart can be shortened.

According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, since the backflow preventing means is provided in the vicinity of the discharge side of the compressor, the backflow inhibiting means is the compressor. The amount of high-pressure gas acting on the compressor can be reduced as the position is closer to the discharge side. Therefore, it is possible to further shorten the time until the pressure is equalized with the low pressure side, and it is possible to further shorten the time required for restarting.

According to the third aspect of the invention, in addition to the effect of the first aspect of the invention, since the backflow prevention means is constituted by the one-way flow means, the high pressure side when the compressor is stopped The reverse flow from the compressor to the compressor can be automatically shut off, and the effect according to the first aspect of the invention can be easily obtained.

According to the invention described in claim 4, in addition to the effect of the invention described in claim 1, since the operation stop is repeated by the intermittent operation, the restart until each restart is performed. By shortening the time, it is possible to significantly reduce the total required time.

According to the invention of claim 5, in addition to the effect of the invention of claim 1, in addition to the effect of the invention of claim 4, when the gas to be liquefied is freon, By performing the intermittent operation, it is possible to suppress excessive cooling of the CFCs and prevent the deterioration of the CFC recovery efficiency due to frost adhesion, etc. Moreover, in the intermittent operation, the time until the restart at each stop of the operation is possible. It is possible to prevent an increase in the entire collection time due to the increase in the weight.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the compressor shown in FIG.

FIG. 3 is a relationship diagram between a pressure leak time in a cylinder chamber and a cylinder pressure.

FIG. 4 is a relationship diagram between a time after a compressor is stopped and a cylinder residual pressure.

FIG. 5 is a relationship diagram between a recovery elapsed time and a recovery rate in intermittent operation.

FIG. 6 is a configuration diagram of a conventional device.

FIG. 7 is an enlarged configuration diagram of the compressor shown in FIG.

[Explanation of symbols]

 2 Compressor 3 Condenser 5 Check valve (backflow prevention means, one-way flow means)

Claims (5)

[Claims] 1. A liquefaction apparatus comprising a compressor for sucking and compressing gas, and a condenser connected to a discharge side of the compressor for cooling and liquefying the compressed gas, wherein the compressor and the condenser are provided. A liquefaction device, which is provided at an intermediate position between and with a backflow blocking means for blocking a backflow from the condenser side to the compressor side while the operation of the compressor is stopped. 2. The liquefaction device according to claim 1, wherein the backflow prevention means is provided at a position near the discharge side of the compressor. 3. The liquefaction apparatus according to claim 1, wherein the backflow prevention means is constituted by a unidirectional flow means that allows only a unidirectional flow from the compressor to the condenser side. 4. The compressor according to claim 1, wherein the compressor is ON and OF
A liquefaction device in which F is alternately repeated at predetermined time intervals to perform intermittent operation so as to suck gas intermittently. 5. The liquefaction device according to claim 4, wherein the gas is freon.