JP4053397B2 - Oil changer for refrigeration cycle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oil changer in a refrigeration cycle such as a refrigeration apparatus or an air conditioner.
[0002]
[Prior art]
As is well known, the refrigeration cycle includes a compressor, a condenser that liquefies refrigerant discharged from the compressor, an expansion valve that expands the liquefied refrigerant, an evaporator that gasifies the expanded refrigerant, and an evaporator. The refrigerant is introduced, and a gas-liquid separator connected to the suction side of the compressor is sequentially coupled by a refrigerant pipe.
The refrigerant sealed in the refrigeration cycle is compressed by the compressor and discharged as a high-temperature and high-pressure gas. At this time, a part of the oil in the compressor is discharged mixed with the refrigerant.
The discharged refrigerant is liquefied by exchanging heat with air in the condenser, and the oil is dissolved in the liquefied refrigerant and moves. The refrigerant and the oil are expanded by the expansion valve through the refrigerant pipe, and are gasified by exchanging heat with the air by the evaporator. At that time, the oil is separated from the refrigerant. The gasified refrigerant returns to the compressor through the gas-liquid separator. On the other hand, the oil moves in a mist state along with the flow of the gas refrigerant, or moves so as to flow through the inner wall while adhering to the inner wall of the refrigerant pipe, and enters the gas-liquid separator.
[0003]
In the gas-liquid separator, the oil is accumulated at the bottom, and when a predetermined amount of oil is accumulated, the oil is sucked from the oil return hole provided in the U-shaped outflow pipe of the gas-liquid separator and returns to the compressor.
Also, the inside of the refrigeration cycle is contaminated with foreign matter and moisture mixed during refrigeration cycle manufacture, and metal powder discharged from the compressor, and the degree of contamination is large when existing piping and existing equipment are used. . When the operation of the refrigeration cycle is continued, these foreign substances and the like circulate and return to the compressor to contaminate the compressor. In a high temperature environment, foreign matter or the like becomes sludge, and the accumulation thereof causes clogging or poor lubrication of the compressor, which becomes a factor that hinders the smooth operation of the refrigeration cycle. Therefore, after trial operation of the refrigeration cycle, the oil is changed regularly, for example, one day later, one month later, and one year later.
[0004]
The oil in the refrigeration cycle is exchanged according to the following procedure.
(1) Recovery of refrigerant First, the operation of the refrigeration cycle is stopped, and the refrigerant in the compressor and the refrigerant circuit connected to the compressor is recovered.
(2) Oil drainage Drain the dirty oil. This is done by leaving residual pressure inside the compressor and discharging the oil from the compressor service port (supply / discharge oil port).
(3) Refueling Supply new oil. Oil is pumped to the compressor service port, or is supplied from another oil plug or the service port on the suction side of the compressor.
(4) Drain air and moisture that have entered the refrigeration cycle and oil during vacuuming. This is performed using a predetermined service port of the refrigeration cycle. (For example, see Patent Document 1)
[0005]
[Patent Document 1]
JP 2001-124447 A (paragraph 0004)
[0006]
[Problems to be solved by the invention]
Since the oil exchange in the conventional refrigeration cycle is the method as described above, it is cumbersome and a great deal of time and labor has been spent until the work is completed. Further, during that time, the operation of the refrigeration cycle has to be stopped, and the cooling function is lost.
Moreover, the oil was exchanged only in the compressor, and the oil staying in the evaporator and the refrigerant pipe could not be exchanged. For this reason, it is impossible to change all the oil in the refrigeration cycle, and it was best to carry out multiple oil changes.
In addition, since the refrigerant that cannot be recovered during the recovery of the refrigerant is released into the atmosphere, it is a problem that cannot be overlooked from the viewpoint of protecting the global environment.
[0007]
The present invention has been made in order to cope with the above-described problems, and can automatically change the oil while operating the refrigeration cycle. By operating for a predetermined time, all the oil in the refrigeration cycle can be changed. An object of the present invention is to provide an oil changer for a refrigeration cycle that can be exchanged and that can minimize the refrigerant released into the atmosphere.
[0008]
[Means for Solving the Problems]
An oil changer for a refrigeration cycle according to the present invention is an oil changer that circulates in a refrigeration cycle that includes a compressor and a gas-liquid separator connected to the suction side thereof. An oil recovery container connected to the opening via an oil recovery valve and replacement oil are sealed, and an oil supply container connected to the supply / discharge oil outlet or suction side of the compressor via an oil supply valve and the oil recovery container And a pump for making the internal pressure of the oil recovery container lower than the internal pressure of the gas-liquid separator and making the internal pressure of the oil supply container higher than the internal pressure of the compressor.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a state in which the oil changer according to Embodiment 1 is connected to a refrigeration cycle.
In this figure, the refrigeration cycle is indicated by reference numeral 1, and a compressor 2, a condenser 3, an expansion valve 4, an evaporator 5, and a gas-liquid separator 6 connected to the suction side of the compressor are sequentially provided. The refrigerant pipe 7 is connected and configured. The compressor 2 is provided with a compressor service port 2B for supplying and discharging the lubricating oil 2A at the bottom, and the gas-liquid separator 6 has an inflow pipe 6A for introducing the gas refrigerant from the evaporator 5. A U-shaped outflow pipe 6B for returning only the gas refrigerant separated from the liquid refrigerant in the gas-liquid separator to the compressor 2 and an oil recovery port 6C located at the bottom are provided.
On the other hand, the refrigeration cycle oil changer 10 includes an oil recovery container 11, an oil recovery valve 12 provided in the inlet pipe 11A, an oil supply container 13, an oil supply valve 14 provided in the outlet pipe 13B, and an oil The pump 15 is connected between the outlet pipe 11 </ b> B of the recovery container 11 and the inlet pipe 13 </ b> A of the oil supply container 13 and communicates with the oil recovery container 11 and the oil supply container 13.
[0010]
Next, the operation of this embodiment will be described. Since the operation of the refrigeration cycle 1 is as described in the prior art, it will be omitted and the operation of the oil changer 10 will be described.
The oil changer 10 evacuates the oil recovery container 11 before connecting to the refrigeration cycle 1, encloses the oil 13 </ b> C to be replaced in the oil supply container 13, and vacuums the whole.
Subsequently, the oil changer 10 is connected to the refrigeration cycle 1 where the oil change is desired. In the connection procedure, the oil recovery valve 12 is connected to the oil recovery port 6C of the gas-liquid separator 6, and the oil supply valve 14 is connected to the compressor service port 2B of the compressor 2. The oil supply valve 14 may be connected to the suction side of the compressor 2, that is, in the middle of the refrigerant pipe 7 between the compressor 2 and the gas-liquid separator 6 as long as the oil can be supplied to the compressor 2. Next, the oil recovery valve 12 and the oil supply valve 14 are opened, and the pump 15 is operated. The relationship between the pressure P1 in the gas-liquid separator 6, the pressure P2 in the compressor 2, the pressure P3 in the oil recovery container 11, and the pressure P4 in the oil supply container 13 is as follows.
P4> P2, P1> P3
Due to this pressure relationship, the contaminated oil circulating in the refrigeration cycle 1 is separated by the gas-liquid separator 6 and stored in the oil recovery container 11 through the oil recovery port 6C.
On the other hand, new oil in the oil supply container 13 is supplied to the compressor 2 through the compressor service port 2B, and the oil is exchanged. When the oil change operation is completed, the oil recovery valve 12 and the oil supply valve 14 are closed and the pump 15 is stopped, and the oil changer 10 is disconnected from the refrigeration cycle 1 to complete the oil change. Thereafter, the refrigerant in the oil changer 10 is recovered and the oil in the oil changer 10 is discharged.
[0011]
In this way, it is possible to prevent the oil in the compressor 2 from being contaminated even when the oil circulating through the refrigeration cycle is dirty. Further, even when the inside of the compressor 2 is already contaminated, new oil is sequentially supplied to replace the contaminated oil. Therefore, the oil can be changed automatically while operating the refrigeration cycle 1. If the oil changer is operated for a predetermined time, not only the compressor 2 but also all the oil in the refrigeration cycle 1 can be changed. In addition, since the oil changer is disconnected from the refrigeration cycle after the oil change operation, the refrigerant in the oil changer 10 can be recovered with a margin (without working on-site). Therefore, the refrigerant can be reliably recovered and the refrigerant released into the atmosphere can be minimized.
[0012]
FIG. 2 is a schematic diagram showing another example of this embodiment.
In this figure, the same or corresponding parts as in FIG. The difference from FIG. 1 is that the compressor 2 is provided with an oil amount detector 2C for detecting the oil amount. As the oil amount detector 2C, one that detects the oil level with a level sensor, one that directly processes the oil level, and the like are known. Moreover, what detects the mass change of the compressor 2 may be used. The oil amount detector 2C detects the amount of oil in the compressor 2 and opens and closes the oil supply valve 14 to supply the required amount of oil.
In this way, the oil change can be performed automatically while adjusting the oil amount in the compressor 2, so that a highly reliable oil change operation can be performed, and the oil amount of the compressor 2 can be reduced during the oil change operation. It is possible to prevent a situation in which an excess or deficiency leads to a malfunction.
[0013]
Further, an oil amount detector (not shown) for detecting the oil amount may be provided in one or both of the oil recovery container 11 and the oil supply container 13. In this way, the oil changer 10 can be stopped before the oil recovery container 11 overflows, and the overflow can be prevented in advance, and the oil changer 10 is stopped before the oil in the oil supply container 13 runs short. It is possible to prevent oil shortage.
Therefore, the reliability of the oil changer can be improved.
[0014]
Further, the inlet pipe 11A and the outlet pipe 11B of the oil recovery container 11 and the inlet pipe 13A and the outlet pipe 13B of the oil supply container 13 are respectively provided with shut valves (not shown) so that they can be separated from the oil changer 10 and replaced. Also good.
In this way, since the oil change operation can be performed continuously, the oil can be continuously changed even when the amount of oil change is large.
[0015]
Moreover, you may provide heating means (not shown), such as a heater, in one or both of the oil collection container 11 and the oil supply container 13.
If it does in this way, since it can prevent that a refrigerant | coolant stagnates (stagnates) in the oil exchange apparatus 10, the reliable operation | work which can replace only oil can be performed.
[0016]
【The invention's effect】
An oil changer for a refrigeration cycle according to the present invention is an oil changer that circulates in a refrigeration cycle that includes a compressor and a gas-liquid separator connected to the suction side thereof. An oil recovery container connected to the opening via an oil recovery valve and replacement oil are sealed, and an oil supply container connected to the supply / discharge oil outlet or suction side of the compressor via an oil supply valve and the oil recovery container And a pump that makes the internal pressure of the oil recovery container lower than the internal pressure of the gas-liquid separator and the internal pressure of the oil supply container higher than the internal pressure of the compressor. Oil can be changed automatically while operating the cycle, and if the oil changer is operated for a predetermined time, not only the compressor but also all the oil in the refrigeration cycle can be changed.
In addition, since the oil changer is disconnected from the refrigeration cycle after the oil change operation, the refrigerant in the oil changer 10 can be recovered with a margin (without working on-site). Therefore, the refrigerant can be reliably recovered and the refrigerant released into the atmosphere can be minimized.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a state where an oil changer according to Embodiment 1 of the present invention is connected to a refrigeration cycle.
FIG. 2 is a schematic diagram showing a different example of the first embodiment of the present invention.
[Explanation of symbols]
1 refrigeration cycle, 2 compressor, 2B compressor service port, 6 gas-liquid separator, 6C oil recovery port, 10 oil changer,
11 Oil recovery container, 12 Oil recovery valve, 13 Oil supply container,
14 Refueling valve, 15 Pump.

Claims (5)

In an oil changer that circulates in a refrigeration cycle including a compressor and a gas-liquid separator connected to the suction side, oil connected to an oil recovery port of the gas-liquid separator via an oil recovery valve A recovery container and replacement oil are sealed, and the oil recovery container connected to the supply / discharge oil outlet or suction side of the compressor via an oil supply valve and the oil recovery container and the oil supply container are connected to each other. An oil changer for a refrigeration cycle comprising a pump that lowers the internal pressure of the gas-liquid separator below the internal pressure of the gas-liquid separator and increases the internal pressure of the oil supply container above the internal pressure of the compressor. 2. The oil changer for a refrigeration cycle according to claim 1, wherein an oil amount detector for detecting the oil amount is provided in the compressor. The oil changer for a refrigeration cycle according to claim 1 or 2, wherein an oil amount detector for detecting an oil amount is provided in one or both of the oil recovery container and the oil supply container. The oil changer for a refrigeration cycle according to any one of claims 1 to 3, wherein a shut-off valve is provided at each of the oil recovery container and the oil supply container. The oil changer for a refrigeration cycle according to any one of claims 1 to 4, wherein heating means is provided in one or both of the oil recovery container and the oil supply container.

Images