JP5084714B2 - Air conditioner - Google Patents

Description

  The present invention diverts existing refrigerant piping using a fluorocarbon hydrogen refrigerant (old refrigerant) containing chlorine to an outdoor unit and an indoor unit compatible with a fluorocarbon hydrogen refrigerant (new refrigerant) that does not contain chlorine. More specifically, the present invention relates to an air conditioner that suppresses deterioration of refrigerating machine oil due to chlorine compounds remaining in existing refrigerant piping.

As a conventional technique, for example, as shown in FIG. 2, there is an air conditioner including a chloride recovery unit 10 connected in parallel to a decompression unit 3 inserted in a main pipe of an outdoor unit X.
When the chloride recovery operation is performed, the four-way valve 7 communicates the discharge side of the compressor 1 and the outdoor heat exchanger 2, and communicates the suction side of the compressor 1 and the gas side extended refrigerant pipe 6 that is an existing refrigerant pipe. To do. The decompression means 3 is fully closed, and the on-off valves 11a and 11b are opened to form a chloride recovery circuit. Thereby, the refrigerant discharged from the compressor 1 can flow through the chloride recovery means 10.

  The refrigerant discharged from the compressor 1 reaches the four-way valve 7, the outdoor heat exchanger 2, the on-off valve 11a, and the chloride recovery means 10. Here, the chlorine compound remaining in the existing refrigerant pipe is adsorbed. Thereafter, the on-off valve 11b, the liquid side extended refrigerant pipe 5 which is the other existing refrigerant pipe, the indoor heat exchanger 4 of the indoor unit Y, and the gas side extended refrigerant pipe 6 are sequentially circulated. Return to the suction port of the compressor 1 (see, for example, Patent Document 1).

Japanese Patent No. 3855884 (5th page, FIG. 3)

  In the above-described conventional air conditioner, it is necessary to perform a dedicated operation for adsorbing and removing chlorine compounds remaining in the existing refrigerant pipe, which is different from the air conditioning operation. There was a problem that the replacement work took time.

  Further, there is no mention of periodically checking the state of the refrigerating machine oil corresponding to the new refrigerant and notifying the user or the inspector as necessary after the outdoor unit and the indoor unit are switched.

  The present invention has been made in order to solve the above-described problems, and is intended to suppress deterioration of refrigerating machine oil suitable for a new refrigerant without performing a dedicated operation for adsorption removal of chlorine compounds. An object of the present invention is to provide an air conditioner capable of periodically checking the state of the air conditioner.

An air conditioner according to the present invention is provided in an outdoor unit in an air conditioner that diverts an existing refrigerant pipe in which an old refrigerant containing chlorine is used to an outdoor unit and an indoor unit adapted to a new refrigerant not containing chlorine. The temperature detecting means for detecting the temperature of the compressor refrigeration oil, the current detecting means for detecting the current flowing through the compressor, the detected temperature of the temperature detecting means and the detected current of the current detecting means exceeded the respective threshold values . Sometimes, if the rotational speed of the compressor in the outdoor unit and the opening of the pressure reducing means are controlled, and the detected temperature and the detected current do not fall below the respective threshold values even after a predetermined time has passed, the refrigeration oil has deteriorated. and control means for judging, in which a display means for displaying the judgment result of the control means.

In the present invention, when the detected temperature of the temperature detecting means and the detected current of the current detecting means exceed the respective threshold values, the number of rotations of the compressor in the outdoor unit and the opening degree of the decompressing means are controlled respectively for a predetermined time. When the detected temperature and the detected current do not fall below the respective threshold values even after the lapse of time, it is determined that the refrigerating machine oil has deteriorated , and the determination result is displayed on the display means . This avoids deterioration of the refrigeration oil without performing a dedicated operation to adsorb and remove the residue in the existing refrigerant piping, and also grasps the state of the refrigeration oil after changing to a new refrigerant, causing the refrigeration oil to deteriorate. It can be controlled not to. In addition, by notifying users and inspectors of the deterioration of refrigeration oil before the summer / winter season when this equipment is used for a long time, serious problems such as compressor failure and clogging of the decompression means during the summer / winter season will occur. It becomes possible not to occur.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a refrigerant circuit diagram showing a schematic configuration of an air-conditioning apparatus according to an embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the part similar to the prior art example demonstrated in FIG.
The air conditioner shown in FIG. 1 includes an outdoor unit X and an indoor unit Y in which R410A refrigerant, which is a new refrigerant, is used, and existing refrigerant pipes 5 and 6 that connect both the outdoor unit X and the indoor unit Y. Has been. The existing refrigerant pipes 5 and 6 are used for the air conditioner using the R22 refrigerant which is the old refrigerant. The compressor 1 of the outdoor unit X uses synthetic oil such as ester oil or ether oil that is compatible with the new refrigerant (R410A) as the refrigeration oil (lubricating oil), and detects the temperature of the refrigeration oil. Part THA (temperature detection means) is provided.

  The control unit 10 is mounted on the control board, and based on an operation command from the indoor unit Y, the number of rotations of the motor of the compressor 1 (hereinafter referred to as “compressor motor”), the fan motor of the outdoor heat exchanger 2, the pressure reduction The opening degree of the expansion valve 3 and the valve switching of the four-way valve 7 are controlled. When starting the cooling operation, the high-temperature and high-pressure gas refrigerant that is the new refrigerant (R410A) discharged from the compressor 1 flows into the outdoor heat exchanger 2 that acts as a condenser, and from the indoor unit Y. The four-way valve 7 is switched so that the low-temperature and low-pressure gas refrigerant (R410A) is sucked into the compressor 1. When starting the heating operation, the high-temperature and high-pressure gas refrigerant (R410A) discharged from the compressor 1 is sent to the indoor unit Y, and the low-temperature / high-pressure from the outdoor heat exchanger 2 acting as an evaporator The four-way valve 7 is switched so that the low-pressure gas refrigerant (R410A) is sucked into the compressor 1. The above-described control unit 10 periodically determines the temperature of the refrigerating machine oil detected by the refrigerating machine oil temperature detection unit THA and the current of the compressor motor detected by the current detection unit SA during operations such as cooling and heating. It is read and it is determined whether or not each threshold value is exceeded, and it is determined whether or not the viscosity of the refrigerating machine oil of the compressor 1 is lowered (deteriorated) based on the result.

Here, the mechanism of deterioration of the refrigerating machine oil will be briefly described.
When water or heat is applied to synthetic oil such as ester oil or ether oil, it is hydrolyzed and pyrolyzed to generate an acid and deteriorate the refrigerating machine oil. At that time, if a chlorine compound is present, the chlorine compound acts as a catalyst, and hydrolysis and thermal decomposition are promoted. In addition, if a chlorine compound is present in a place where sliding is performed with high-temperature iron, a mechanochemical reaction occurs, which reacts with the iron on the surface to decompose foreign matter (sludge) called metal soap and refrigeration oil, thereby reducing fatty acid. Occurs or lowers (deteriorates) the viscosity of refrigerating machine oil. The latter reaction can be suppressed if the surface temperature of sliding parts such as shafts and bearings in the compressor 1 is not increased.

Next, a phenomenon that occurs when the surface temperature of a sliding portion such as a shaft or a bearing becomes high will be described.
The compressor 1 is a high-pressure shell type. Usually, refrigeration oil is present between the shaft and the bearing so that the shaft and the bearing are not in direct contact with each other. However, when the refrigerating machine oil deteriorates and the viscosity decreases, it cannot exist between the shaft and the bearing, and the shaft and the bearing slide while rotating. At this time, the sliding portion becomes a high temperature that far exceeds the upper limit temperature of the discharge-side refrigerant of the compressor 1. The refrigerating machine oil in the compressor 1 is normally accumulated in the lower part, and the refrigerating machine oil is supplied to sliding parts such as a shaft, a bearing, and a cylinder part by an oil supply pump or the like. A part of the supplied refrigeration oil is discharged from the discharge pipe of the compressor 1 to the outside of the compressor 1 together with the refrigerant discharged from the cylinder, but most of it falls and returns to the lower part of the compressor 1. Since the refrigerating machine oil that passes through the sliding portion where the metals are in contact with each other is at a high temperature, the temperature of the refrigerating machine oil in the compressor 1 is extremely high. On the other hand, it can be said that the refrigerant compressed in the cylinder of the compressor 1 is substantially unchanged as compared with the degree of increase in the temperature of the refrigerating machine oil.

  When metals come into contact with each other at a sliding portion such as a shaft or a bearing in the compressor 1, the torque applied to the rotation of the shaft increases rapidly, and as a result, the current value of the compressor motor increases rapidly. If the temperature of the refrigerating machine oil and the current of the compressor motor increase, it can be determined that the viscosity of the refrigerating machine oil has decreased and deteriorated.

  Therefore, in the present embodiment, as described above, the control unit 10 periodically detects the temperature of the refrigerating machine oil detected by the refrigerating machine oil temperature detection unit THA and the compressor motor detected by the current detection unit SA. The current is read to determine whether or not the respective threshold values are exceeded, and based on the result, it is determined whether or not the viscosity of the refrigerating machine oil of the compressor 1 has deteriorated.

  For example, when the upper limit temperature (threshold value) of the refrigeration oil is 120 ° C. and the upper limit current (threshold value) of the compressor motor is 30 A, the detection temperature of the refrigeration oil temperature detection unit THA exceeds 120 ° C., and the current detection unit SA When the detected current exceeds 30 A, control is performed so that the rotation speed of the compressor motor is lowered (for example, the drive frequency of the compressor motor is lowered), and the opening degree of the expansion valve 3 is adjusted to be reduced. In this state, when the temperature of the refrigerating machine oil and the current of the compressor motor become below the respective threshold values, the operation is switched to the operation based on the operation command from the indoor unit Y. On the other hand, if the detected temperature and the detected current do not fall below the respective threshold values even after a predetermined time has elapsed, it is determined that the refrigerating machine oil has deteriorated and, for example, a lamp (for example, a display unit provided in the indoor unit Y) (Not shown) is lit or blinked to notify the user or inspector of that fact. A lamp may be installed outside the room.

  As described above, according to the embodiment, when the detection temperature of the refrigerator oil temperature detection unit THA exceeds 120 ° C. and the detection current of the current detection unit SA exceeds 30 A, the rotation speed of the compressor motor decreases. If the detected temperature and the detected current do not fall below the respective threshold values even after a predetermined time has elapsed, the refrigerating machine oil has deteriorated. Since the lamp of the display means is turned on or blinked to notify the user or inspector of that fact, a dedicated operation for adsorbing and removing the residue in the existing refrigerant pipes 5 and 6 is performed. It is possible to avoid deterioration of the refrigerating machine oil without performing it, and to grasp the state of the refrigerating machine oil even after changing the working refrigerant, and to control the refrigerating machine oil not to deteriorate. In addition, by notifying users and inspectors of the deterioration of refrigeration oil before the summer / winter season when the air conditioner is used for a long time, the compressor 1 malfunctions during the summer / winter season and the expansion valve 3 is clogged. It becomes possible to prevent a serious malfunction from occurring.

It is a refrigerant circuit figure showing a schematic structure of an air harmony device concerning an embodiment of the invention. It is a refrigerant circuit figure which shows the conventional air conditioning apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 Outdoor heat exchanger, 3 Expansion valve, 4 Indoor heat exchanger, 5, 6 Existing refrigerant piping, 7 Four way valve, 10 Control part, X outdoor unit, Y indoor unit, THA refrigerator oil temperature detection part, SA Current detector.

Claims (2)

In an air conditioner that diverts existing refrigerant piping that uses an old refrigerant containing chlorine to outdoor units and indoor units that are compatible with new refrigerants that do not contain chlorine,
Temperature detecting means for detecting the temperature of the refrigerating machine oil of the compressor provided in the outdoor unit;
Current detection means for detecting current flowing in the compressor;
When the detected temperature of the temperature detecting means and the detected current of the current detecting means exceed the respective threshold values, the number of revolutions of the compressor in the outdoor unit and the opening of the pressure reducing means are controlled, and a predetermined time has elapsed. even the detected temperature and the control means detecting current is determined and the refrigerator oil when not fall below the respective threshold value is degraded,
An air conditioner comprising: display means for displaying a determination result of the control means. The outdoor unit compressor of a high pressure shell type, the compressor according to claim 1 Symbol placement of the air conditioner, characterized in that said temperature detecting means is mounted in contact with the shell surface of the.

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