JP2004333086A - Refrigerant recovery device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform recovery work without remains regardless of the number of outdoor units connected and to secure the reliability of a refrigerant recovery device in the device for recovering refrigerant from a plurality of exterior units at the same time. <P>SOLUTION: This refrigerant recovery device is provided with: a connecting part 5 to equipment 9a subjected to refrigerant recovery; a driving means 1 for sucking refrigerant gas from the equipment subjected to refrigerant recovery; and a storing container 4 storing the recovered refrigerant gas. The device further is provided with: a pressure detecting means 3 for detecting the pressure of the refrigerant gas of the above equipment subjected to refrigerant recovery; and an opening and closing means 2a for opening and closing a passage on the compressor intake side, wherein during the refrigerant recovery operation, the pressure detecting means closes the opening and closing means 2a and clocks designated time when the pressure detecting means detects that it is below a first designated pressure, and when the pressure detected by the pressure detecting means 3 is higher than a second designated pressure, the opening and closing means 2a is opened to again perform refrigerant recovery. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a refrigerant recovery device that recovers a refrigerant gas from an air conditioner, a car cooler, or the like.
[0002]
[Prior art]
Conventionally, this type of refrigerant recovery device that recovers refrigerant gas from air conditioners and car coolers has not yet completed refrigerant recovery due to slow evaporation of refrigerant gas from the refrigerant recovery device at low temperatures, such as during winter. Nevertheless, in order to prevent the refrigerant recovery operation from being completed and stopped, it is detected whether or not there is a pressure increase due to refrigerant evaporation from the refrigerant recovery device for a predetermined time even after the refrigerant recovery operation is once completed, If the pressure exceeds a predetermined value after a predetermined time, there is a refrigerant recovery device configured to start the compressor again to perform a refrigerant recovery operation (for example, refer to Japanese Patent Application Laid-Open No. H11-157131).
[0003]
FIG. 4 shows an outline of the invention of the conventional refrigerant recovery device described in the above publication. In FIG. 4, reference numeral 9a denotes an outdoor unit of an air conditioner in which refrigerant gas is stored, which is connected to the suction port 5 of the refrigerant recovery device B via a connection hose 10a. On the other hand, in the refrigerant recovery device B, the refrigerant gas recovery container 4 is sequentially supplied from the suction port 5 via the evaporator 6, the vaporization tank 7, the oil separator 8, the accumulator 9, the compressor 1, the condenser 13, and the check valve 12. The refrigerant gas is sucked from the outdoor unit 9 a of the air conditioner by driving the compressor 1, condensed, and sealed in the collection container 4 in a liquid state as much as possible. For details, an on-off valve 8a that opens and closes when the oil separated by the oil separator 8 is taken out, a second on-off valve 2b that opens and closes a bypass path between the discharge side and the suction side of the compressor 1, and an outlet of the condenser 13 A liquid refrigerant recirculation passage 19 is provided which is connected to the suction side of the compressor 1 through a flow control valve 11 having a variable flow rate, and guides a part of the liquefied liquid refrigerant to the compressor suction to cool the compressor 1. It is configured to assist. Further, a pressure sensor 3 for detecting the pressure of the refrigerant gas on the outdoor unit side is provided, and the operation of the compressor 1 is controlled by the control means 20 according to the pressure.
[0004]
Next, a refrigerant recovery operation using the refrigerant recovery apparatus having the above configuration will be described. During operation of the refrigerant recovery device, the second on-off valve 2b is opened so that the compressor 1 is easily started for an initial predetermined time, and then closed to suck refrigerant gas from the outdoor unit. At the beginning of the recovery operation, the refrigerant gas pressure detected by the pressure sensor 3 is high according to the temperature environment to which the outdoor unit is exposed. After stopping the operation of the compressor 1 and waiting for a predetermined period of time, if the refrigerant gas pressure detected by the pressure sensor 3 has risen to a pressure equal to or higher than the reference pressure for completing the refrigerant recovery, the compressor is restarted to start the operation. Control is performed so as to remove the residual gas from the outdoor unit 9a as a refrigerant recovery device as much as possible to complete the refrigerant recovery operation.
[0005]
In addition, in the refrigerant recovery device as described above, the recovery capacity of the refrigerant recovery device is determined on the assumption that the recovery operation is performed by connecting the plurality of outdoor units in which the refrigerant is sealed so that the refrigerant gas can be recovered at a time. The operating capacity of the compressor is prepared in advance so as to correspond to the maximum number of connected refrigerant recovery outdoor units.
[0006]
[Patent Document 1]
JP-A-8-189773
[Problems to be solved by the invention]
In the above-described conventional configuration, the capacity of the drive device that determines the operation capacity of the refrigerant recovery device is set according to the maximum recovery amount, and at the time of the refrigerant recovery operation, the operation is performed at the recovery capacity (almost constant capacity). When the number of connections to be recovered is considerably smaller than the maximum number of connections, the pressure drops rapidly even if the refrigerant recovery has not yet been completely completed, and the refrigerant recovery device drops the recovery side pressure. Will be controlled. That is, when the number is small, such detection is performed even though the refrigerant is not sufficiently recovered yet, and as a result, the refrigerant recovery operation ends even when some refrigerant gas still remains in the recovery target. Therefore, there is a problem that the remaining refrigerant gas may remain as it is in the object to be recovered.
[0008]
On the other hand, when the number of refrigerant recovery devices changes, the compressor may also be changed to a variable speed to change the speed according to the number of connected refrigerants and the recovery amount. Since the operating capacity must be set or changed each time according to the equipment, the equipment becomes complicated, and the reliability is secured considerably by using an inverter control device for severe operating conditions such as refrigerant recovery. It becomes difficult, and an increase in equipment cost is easily expected.
[0009]
The present invention solves the above-mentioned conventional problems, and in a refrigerant recovery device that recovers refrigerant from a plurality of outdoor units at once, performs a recovery operation so that there is no recovery regardless of the number of connected units, and a reliable operation. It is an object of the present invention to provide a refrigerant recovery device having high performance.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned conventional problems, the refrigerant recovery device of the present invention includes a connection part with a refrigerant recovery device storing at least the refrigerant gas to be recovered, and a driving unit that sucks the refrigerant gas from the refrigerant recovery device. A refrigerant detection device configured to include a pressure detection unit that detects a refrigerant gas pressure of the refrigerant collection device, and a first opening / closing unit that opens and closes a suction-side path of the driving unit; At the time of the recovery operation, the first opening / closing means is opened, and when the pressure detecting means detects that the pressure is equal to or less than a predetermined pressure, the first opening / closing means is closed to increase the pressure increase on the refrigerant collection equipment side. It is characterized in that the presence or absence of the refrigerant is detected to determine whether or not the refrigerant collection is completed.
[0011]
With this, in the refrigerant recovery device using the drive unit whose capacity is selected according to the maximum connectable number of the refrigerant recovery devices, even when only a small number of the refrigerant recovery devices are connected, the residual gas of the refrigerant recovery device is removed. The refrigerant recovery operation can be performed reliably by judging the presence / absence, and the drive means is not turned off even if the recovery pressure once drops to the predetermined pressure for judging the completion of recovery by the pressure detection means, so the drive means is frequently turned on. It is possible to perform the refrigerant recovery operation without turning on / off, and to improve the reliability of the apparatus.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention according to claim 1 is a connection portion with at least a refrigerant recovery device storing refrigerant gas to be recovered, a driving unit for sucking the refrigerant gas from the refrigerant recovery device, and a refrigerant gas of the refrigerant recovery device. A refrigerant recovery device comprising: a pressure detection unit that detects pressure; and a first opening / closing unit that opens and closes a suction-side path of the driving unit. The means is opened, and when the pressure detecting means detects that the pressure is equal to or less than a predetermined pressure, the first opening / closing means is closed to detect the presence or absence of a pressure increase on the refrigerant collection device side, thereby completing the refrigerant collection. It is characterized by judging whether it is right or wrong.
[0013]
With this, in the refrigerant recovery device using the driving means whose capacity is selected according to the maximum connectable number of the refrigerant recovery devices, even when only a small number of the refrigerant recovery devices are connected, the residual gas of the refrigerant recovery device is removed. The refrigerant recovery operation can be performed reliably by judging the presence / absence, and the drive means is not turned off even if the recovery pressure once drops to the predetermined pressure for judging the completion of recovery by the pressure detection means, so the drive means is frequently turned on. The refrigerant recovery operation can be performed without turning on / off the refrigerant, the reliability of the device can be improved, and the refrigerant can be reliably recovered from the refrigerant recovery device regardless of the number of the refrigerant recovery devices. It is possible to provide a refrigerant recovery device that reduces the burden on the refrigerant and improves reliability.
[0014]
According to a second aspect of the present invention, the discharge port and the suction port of the driving means are connected through the second opening / closing means, and when at least the first opening / closing means is closed during the refrigerant recovery operation, the second port is closed. The opening / closing means is controlled to be open.
[0015]
Thus, when the first opening / closing means is closed, the suction side of the driving means may be reduced to a negative pressure state close to vacuum. The load can be reduced, and even if the first opening / closing means is closed while the driving means is operating, the load on the driving means can be reduced, and the reliability of the driving means can be improved.
[0016]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. Components having the same configuration and functions as those of FIG. 4 used in the description of the related art are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0017]
The configuration of the present embodiment is different from the configuration of FIG. 4 described in the related art, as shown in the schematic configuration diagram of the present embodiment of FIG. 1 is that it has an on-off valve 2a and that it has a path 18 that communicates from the gas phase portion of the oil storage tank communicating with the vaporization tank 7 to the upstream side of the pressure sensor 3. Note that, in the present embodiment, the configuration of the refrigerant recovery device A indicated by a dashed line in FIG. 1 does not include the recovery container 4 and is connected to the outside via the recovery container connection port 14 as a separate body from the refrigerant recovery device. Although it is configured, there is no problem if it is treated as a part of the refrigerant recovery device and incorporated into the device. Further, when a certain amount of oil remains in the vaporization tank 7, the on-off valve 16 is opened automatically or manually to guide the oil to the oil recovery container 17. Since the refrigerant residual gas may be dissolved in the oil, the gas phase side of the oil recovery container 17 may be connected to the refrigerant recovery path.
[0018]
Here, the first opening / closing valve 2a is controlled in opening / closing operation by the control means 20 based on the refrigerant gas pressure detected by the refrigerant recovery operation pressure sensor 3, so that the refrigerant recovery path on the suction side of the compressor 1 (drive device) is moved. Open and close.
[0019]
Next, a refrigerant recovery operation using the refrigerant recovery apparatus will be described with reference to FIGS. When the outdoor unit 9a, 9b,..., 9c, which is the refrigerant collection device, is connected to the connection port 5 and the closing valve (not shown) of the outdoor unit is opened, the refrigerant gas in the outdoor unit recovers the refrigerant. It flows into the device A. At this time, the first on-off valve 2a may be closed when the refrigerant flows from the outdoor unit before the start of the refrigerant recovery operation, and may be opened after the compressor 1 is started. Then, the influence of the pressure of the refrigerant gas at the time of starting the compressor 1 is small, and the starting failure is less likely to occur. At this time, the on-off valve 16 is closed and the flow control valve 11 is also closed. This is the preparation stage for the refrigerant recovery operation.
[0020]
Next, when the refrigerant recovery operation switch (not shown) is turned on, the compressor 1 is driven. At this time, if the second on-off valve 2b provided in the path bypassing the discharge side and the suction side of the compressor 1 is opened for a predetermined time, the starting load is reduced, which is preferable.
[0021]
When the compressor 1 is started, the first on-off valve 2a is opened, the second on-off valve 2b is closed (Step S101), and a refrigerant recovery operation is performed. As shown in a region D1 of FIG. The operation is performed until time t1 when P <p2 (p2 is one of pressure references for judging completion of refrigerant recovery) (step S102). At this time, as shown by the one-dot chain line in FIG. 2, if P <p2 does not hold even when the predetermined time t0 has elapsed, the recovery process is performed smoothly due to a problem such as a gas leak in the suction path or a defective compressor. Since it is conceivable that the process does not proceed to step (1), an abnormality display is displayed to urge the user to confirm the malfunction of the apparatus (steps S103 and S104).
[0022]
When it is confirmed in step S102 that P <p2, the first on-off valve 2a is closed while the compressor 1 is operating (step S105), and the suction side path of the compressor 1 and the refrigerant gas are stored. The connection to the refrigerant recovery machine is cut off. At this time, since the suction side of the compressor 1 is closed, the pressure becomes negative, and if this state continues for a long time, the load may be applied to the compressor. Therefore, if the second on-off valve 2b is opened at this time, It is suitable. Alternatively, when a bypass path to which the second on-off valve is connected is not provided, the flow control valve 11 attached to the liquid refrigerant return path 19 may be appropriately opened. In this way, the compressor operation is continued while applying no load to the compressor as much as possible, while waiting for a predetermined time ΔT1 from t1 to t2 as shown in a region D2 of FIG. 2 to connect the outdoor unit. The change in the pressure of the refrigerant gas is detected (step S106).
[0023]
P> p1 (p1 ≧ p2, the pressure of the residual gas in the refrigerant collection device system path once decreases to p2, and a pressure reference that allows the return of pressure due to evaporation of the residual gas to be completed as refrigerant recovery when the refrigerant is left standing. ), The process moves to the region D3 in FIG. 2, the first on-off valve is opened again, and the second on-off valve is switched between closed and operated (step S107), and the gas recovery operation is performed again (step S108).
[0024]
For a predetermined time from the start of the gas recovery operation in steps S101 and S108 for opening the first on-off valve, even if P <p2, the valve switching operation frequently occurs and the pressure fluctuation frequently occurs. In order to prevent problems, it is preferable not to shift to the next on-off valve switching operation such as S105.
[0025]
When P <p2 is detected again at time t3, step S105 is performed again to open and close the first and second on-off valves, and as shown in a region D4 in FIG. 2, this time ΔT2 from t3 to t4. Just wait. ΔT2 may be the same time as the previous ΔT1, but if the refrigerant recovery operation is proceeding favorably, the residual gas pressure is expected to decrease considerably. It is considered that the presence or absence of the increase in the residual gas pressure can also be determined.
[0026]
If the residual gas pressure is P ≧ p1 after ΔT2, the process proceeds to step S108 again to continue the refrigerant recovery operation, while if P <p1, it is determined that the refrigerant recovery operation has been completed, and the compressor 1 is turned off and the first refrigerant recovery operation is stopped. The on-off valve 2a is opened (step S109), and the process ends. At this time, although not explicitly shown in the figure, it is also possible to introduce external air into the decompressed compressor suction path, equalize the pressure, and end the processing.
[0027]
【The invention's effect】
As described above, according to the present invention, the refrigerant is reliably recovered from the refrigerant recovery device regardless of the number of the refrigerant recovery devices, and the load on the driving unit is reduced to improve the reliability. A refrigerant recovery device can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a refrigerant recovery device according to Embodiment 1 of the present invention. FIG. 2 is an operation time chart of the refrigerant recovery device according to Embodiment 1 of the present invention. FIG. Control flowchart of refrigerant recovery device [FIG. 4] Schematic diagram of configuration of conventional refrigerant recovery device [Description of reference numerals]
1 compressor (drive means)
2a First open / close valve (first open / close means)
2b Second on-off valve (second on-off means)
3 pressure sensor (pressure detection means)
4 Collection container 5 Connection port (connection part)
9a Outdoor unit 10a Connection hose 11 Flow control valve 20 Control means

Claims (3)

At least, a connection portion with the refrigerant collection device storing the refrigerant gas to be collected, a driving unit that sucks the refrigerant gas from the refrigerant collection device, and a pressure detection unit that detects a refrigerant gas pressure of the refrigerant collection device. A first opening / closing means for opening / closing a suction-side path of the driving means, wherein the first opening / closing means is opened during the refrigerant collecting operation, and the pressure detection is performed. When the means detects that the pressure is equal to or less than a predetermined pressure, the first opening / closing means is closed to detect the presence or absence of a pressure increase on the refrigerant collection device side, and to judge whether refrigerant collection is completed. Refrigerant recovery device. The discharge port and the suction port of the driving means are connected via the second opening / closing means, and the second opening / closing means is open when at least the first opening / closing means is closed during the refrigerant recovery operation. The refrigerant recovery device according to claim 1, wherein the refrigerant recovery device is controlled to: At least pressure detecting means for detecting the refrigerant gas pressure of the refrigerant collection device, driving means for sucking the refrigerant gas from the refrigerant collection equipment, and opening and closing means for opening and closing the suction side path of the driving means. A refrigerant recovery method performed by using the configured refrigerant recovery device, wherein a refrigerant recovery step of performing a refrigerant recovery operation, a residual gas confirmation step of confirming the presence or absence of residual gas in the refrigerant recovery device, and the pressure detecting means And a completion judging step of judging whether or not the refrigerant collection is completed based on the pressure detected in the step (a). A method for recovering refrigerant, wherein the driving means is not stopped during operation.

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