Control device, refrigeration system, control method, and control program

Abstract

In a system including a compressor including a motor and a compression mechanism, processing circuitry performs handling processing including at least one of output processing for outputting information indicating that the compressor is in a predetermined state and changing processing for changing an operating condition of the system in a case where an index value indicative of a magnitude of a temporal change of a specific frequency component included in a physical amount correlated with a state of the compressor and a predetermined threshold value satisfy a predetermined relationship.

1 . A control device for controlling a system including a compressor including a motor and a compression mechanism, the control device comprising:
 processing circuitry configured to perform handling processing including at least one of output processing for outputting information indicating that the compressor is in a predetermined state and changing processing for changing an operating condition of the system in a case where an index value indicative of a magnitude of a temporal change of a specific frequency component included in a physical amount correlated with a state of the compressor and a predetermined threshold value satisfy a predetermined relationship.   
     
     
         2 . The control device according to  claim 1 , wherein
 the processing circuitry is configured to perform the handling processing in a case where the index value is larger than the threshold value under conditions that an amplitude value of the specific frequency component included in the physical amount obtained during 10 seconds is derived every second, the index value is an absolute value of a difference between a value obtained by dividing a first moving average value (MA1) by a second moving average value (MA2) and 1, the first moving average value (MA1) is an average value of 10 amplitude values derived within a first period (T1) lasting 10 seconds that ends at a time (ti) at which a latest amplitude value is derived, the second moving average value (MA2) is an average value of 180 amplitude values derived within a second period (T2) lasting 3 minutes that ends at a time (ti) at which a latest amplitude value is derived, and the threshold value is set to a value equal to or greater than 1.1 times a maximum value of the index value obtained during a measurement period lasting 10 minutes under a condition that the compressor is in a predetermined steady state.   
     
     
         3 . The control device according to  claim 1 , wherein
 the processing circuitry is configured to perform the handling processing in a case where the index value is larger than the threshold value under conditions that an amplitude value of the specific frequency component included in the physical amount obtained during 10 seconds is derived every second, the index value is an absolute value of a difference between a value obtained by dividing a first moving average value (MA1) by a second moving average value (MA2) and 1, the first moving average value (MA1) is an average value of 10 amplitude values derived within a first period (T1) lasting 10 seconds that ends at a time (ti) at which a latest amplitude value is derived, the second moving average value (MA2) is an average value of 180 amplitude values derived within a second period (T2) lasting 3 minutes that ends at a time (ti) at which a latest amplitude value is derived, and the threshold value is set to 0.1.   
     
     
         4 . The control device according to  claim 1 , wherein
 the compression mechanism includes a compression chamber for compressing a working fluid,   the compression chamber is sealed by a lubricating oil, and   the predetermined state is a state in which sealability of the compression chamber provided by the lubricating oil has failed.   
     
     
         5 . The control device according to  claim 1 , wherein
 the compression mechanism includes a compression chamber for compressing a working fluid,   the compressor includes an oil accumulation portion in which a lubricating oil is accumulated and an oil supply path for supplying the lubricating oil accumulated in the oil accumulation portion to the compression chamber,   the oil supply path has a suction port, and in a case where the suction port is immersed in the lubricating oil accumulated in the oil accumulation portion, the lubricating oil drawn in through the suction port is enabled to be supplied to the compression chamber,   the compression chamber is sealed by the lubricating oil, and   the predetermined state is a state in which the suction port of the oil supply path is not immersed in the lubricating oil accumulated in the oil accumulation portion.   
     
     
         6 . The control device according to  claim 1 , wherein
 the predetermined state is a liquid compression state in which a liquid-form working fluid is drawn into the compression mechanism and is compressed in the compression mechanism.   
     
     
         7 . The control device according to  claim 1 , wherein
 the physical amount is any of a rotation frequency of the motor, a voltage applied to the motor, a current flowing through the motor, vibration of the compressor, a sound of the compressor, and ambient sound around the compressor.   
     
     
         8 . The control device according to  claim 1 , wherein
 a frequency of the specific frequency component is a frequency that is in synchronization with a rotation frequency of the motor.   
     
     
         9 . A refrigeration system comprising:
 a refrigerant circuit including a compressor including a motor and a compression mechanism; and   the control device according to  claim 1 .   
     
     
         10 . A control method for controlling a system including a compressor including a motor and a compression mechanism, the control method comprising:
 an acquisition step of acquiring a physical amount correlated with a state of the compressor; and   a handling step including at least one of an output step of outputting information indicating that the compressor is in a predetermined state and a changing step of changing an operating condition of the system in a case where an index value indicative of a magnitude of a temporal change of a specific frequency component included in the physical amount acquired in the acquisition step and a predetermined threshold value satisfy a predetermined relationship.   
     
     
         11 . A non-transitory computer readable medium storing a control program for causing a computer to perform the control method according to  claim 10 . 
     
     
         12 . The control device according to  claim 2 , wherein
 the compression mechanism includes a compression chamber for compressing a working fluid,   the compression chamber is sealed by a lubricating oil, and   the predetermined state is a state in which sealability of the compression chamber provided by the lubricating oil has failed.   
     
     
         13 . The control device according to  claim 3 , wherein
 the compression mechanism includes a compression chamber for compressing a working fluid,   the compression chamber is sealed by a lubricating oil, and   the predetermined state is a state in which sealability of the compression chamber provided by the lubricating oil has failed.   
     
     
         14 . The control device according to  claim 2 , wherein
 the compression mechanism includes a compression chamber for compressing a working fluid,   the compressor includes an oil accumulation portion in which a lubricating oil is accumulated and an oil supply path for supplying the lubricating oil accumulated in the oil accumulation portion to the compression chamber,   the oil supply path has a suction port, and in a case where the suction port is immersed in the lubricating oil accumulated in the oil accumulation portion, the lubricating oil drawn in through the suction port is enabled to be supplied to the compression chamber,   the compression chamber is sealed by the lubricating oil, and   the predetermined state is a state in which the suction port of the oil supply path is not immersed in the lubricating oil accumulated in the oil accumulation portion.   
     
     
         15 . The control device according to  claim 3 , wherein
 the compression mechanism includes a compression chamber for compressing a working fluid,   the compressor includes an oil accumulation portion in which a lubricating oil is accumulated and an oil supply path for supplying the lubricating oil accumulated in the oil accumulation portion to the compression chamber,   the oil supply path has a suction port, and in a case where the suction port is immersed in the lubricating oil accumulated in the oil accumulation portion, the lubricating oil drawn in through the suction port is enabled to be supplied to the compression chamber,   the compression chamber is sealed by the lubricating oil, and   the predetermined state is a state in which the suction port of the oil supply path is not immersed in the lubricating oil accumulated in the oil accumulation portion.   
     
     
         16 . The control device according to  claim 2 , wherein
 the predetermined state is a liquid compression state in which a liquid-form working fluid is drawn into the compression mechanism and is compressed in the compression mechanism.   
     
     
         17 . The control device according to  claim 3 , wherein
 the predetermined state is a liquid compression state in which a liquid-form working fluid is drawn into the compression mechanism and is compressed in the compression mechanism.   
     
     
         18 . The control device according to  claim 2 , wherein
 the physical amount is any of a rotation frequency of the motor, a voltage applied to the motor, a current flowing through the motor, vibration of the compressor, a sound of the compressor, and ambient sound around the compressor.   
     
     
         19 . The control device according to  claim 3 , wherein
 the physical amount is any of a rotation frequency of the motor, a voltage applied to the motor, a current flowing through the motor, vibration of the compressor, a sound of the compressor, and ambient sound around the compressor.   
     
     
         20 . The control device according to  claim 4 , wherein
 the physical amount is any of a rotation frequency of the motor, a voltage applied to the motor, a current flowing through the motor, vibration of the compressor, a sound of the compressor, and ambient sound around the compressor.