Transport refrigeration apparatus

• US 9,714,781 B2
• Filed: 07/25/2012
• Issued: 07/25/2017
• Est. Priority Date: 07/29/2011
• Status: Active Grant

• Current Assignee: Daikin Industries Ltd
• Original Assignee: Daikin Industries Ltd
• Inventors: Ueno, Akitoshi, Satou, Kiichirou, Nakano, Masataka
• Primary Examiner(s): Walters, Ryan J
• Assistant Examiner(s): Mendoza-Wilkenfe, Erik
• Application Number:
  US14/234,353
• Publication Number:
  US 20140150482A1
• Time in Patent Office: 1,826 Days
• CPC Class Codes: F25B 2600/11 Fan speed control
• CPC Class Codes: F25B 2700/151 of the compressor motor
• CPC Class Codes: F25B 49/02 for compression type machines, plants or systems
• CPC Class Codes: F25D 29/003 for movable devices
• CPC Class Codes: H02H 7/0852 directly responsive to abnormal temperature by using a temperature sensor in a control circuit H02H7/0833
• CPC Class Codes: H02P 29/027 the fault being an over-current
• CPC Class Codes: H02P 29/032 Preventing damage to the motor, e.g. setting individual current limits for different drive conditions

Abstract

According to the present disclosure, in a container refrigeration apparatus configured to cool the inside of a container, the accuracy of determination of occurrence of a lock abnormality and a connection abnormality of a motor is increased, and erroneous detection of the motor abnormalities is reduced or prevented. The container refrigeration apparatus of the present disclosure includes an abnormality determinator configured to compare a value for current flowing through an in-compartment motor with a preset current threshold to determine occurrence of the motor abnormalities of the in-compartment motor, and a threshold changer configured to change the current threshold of the abnormality determinator in accordance with a supply voltage for each supply frequency of a power supply configured to supply power to the in-compartment motor.

Claims

1. A transport refrigeration apparatus including a refrigerant circuit in which a refrigeration cycle is performed, comprising:

a fan configured to supply air to an air heat exchanger connected to the refrigerant circuit;

a fan motor configured to drive the fan;

a power supply sensor that detects a supply frequency and a supply voltage of a power supply configured to supply power to the fan motor;

an abnormality determiner configured to compare a current value for current flowing through the fan motor with a preset current threshold to determine occurrence of a motor abnormality of the fan motor; and

a threshold changer configured to change the current threshold of the abnormality determiner in accordance with the detected supply frequency and the detected supply voltage of the power supply configured to supply power to the fan motor,

wherein the threshold changer stores a plurality of predetermined correlations between the detected supply voltage and the current threshold for respective supply frequencies, each of the plurality of correlations defining a different relationship between the current threshold and the supply voltage, and

when the power supply sensor detects a new supply frequency, the threshold changer calculates based on one of the plurality of correlations corresponding to the new supply frequency, to determine the current threshold to coincide with the detected supply voltage.

2. The transport refrigeration apparatus of claim 1, wherein

if the current value of the fan motor is greater than a preset current threshold for lock abnormality, the abnormality determiner determines that the motor abnormality is a lock abnormality.

3. The transport refrigeration apparatus of claim 2, wherein

for each value for frequency of the power supply, the threshold changer increases the current threshold for lock abnormality when the supply voltage of the power supply increases, and

decreases the current threshold for lock abnormality when the supply voltage of the power supply decreases.

4. The transport refrigeration apparatus of claim 1, wherein

if the current value of the fan motor is less than a preset current threshold for connection abnormality, the abnormality determiner determines that the motor abnormality is a connection abnormality.

5. The transport refrigeration apparatus of claim 4, wherein

for each value for frequency of the power supply, the threshold changer

increases the current threshold for connection abnormality when the supply voltage of the power supply increases, and

decreases the current threshold for connection abnormality when the supply voltage of the power supply decreases.

6. The transport refrigeration apparatus of claim 1, further comprising:

a compressor motor configured to drive a compressor connected to the refrigerant circuit;

an electric circuit connected to the fan motor and the compressor motor;

a first detector configured to detect a current value for current flowing from the power supply to the electric circuit; and

a second detector configured to detect a current value for current flowing through the compressor motor,

wherein the current value for current flowing through the fan motor is determined based on a value obtained by subtracting the current value of the second detector from the current value of the first detector.

7. The transport refrigeration apparatus of claim 2, further comprising:

a compressor motor configured to drive a compressor connected to the refrigerant circuit;

an electric circuit connected to the fan motor and the compressor motor;

a first detector configured to detect a current value for current flowing from the power supply to the electric circuit; and

a second detector configured to detect a current value for current flowing through the compressor motor,

wherein the current value for current flowing through the fan motor is determined based on a value obtained by subtracting the current value of the second detector from the current value of the first detector.

8. The transport refrigeration apparatus of claim 3, further comprising:

a compressor motor configured to drive a compressor connected to the refrigerant circuit;

an electric circuit connected to the fan motor and the compressor motor;

a first detector configured to detect a current value for current flowing from the power supply to the electric circuit; and

a second detector configured to detect a current value for current flowing through the compressor motor,

wherein the current value for current flowing through the fan motor is determined based on a value obtained by subtracting the current value of the second detector from the current value of the first detector.

9. The transport refrigeration apparatus of claim 4, further comprising:

a compressor motor configured to drive a compressor connected to the refrigerant circuit;

an electric circuit connected to the fan motor and the compressor motor;

a first detector configured to detect a current value for current flowing from the power supply to the electric circuit; and

a second detector configured to detect a current value for current flowing through the compressor motor,

wherein the current value for current flowing through the fan motor is determined based on a value obtained by subtracting the current value of the second detector from the current value of the first detector.

10. The transport refrigeration apparatus of claim 5, further comprising:

a compressor motor configured to drive a compressor connected to the refrigerant circuit;

an electric circuit connected to the fan motor and the compressor motor;

a first detector configured to detect a current value for current flowing from the power supply to the electric circuit; and

a second detector configured to detect a current value for current flowing through the compressor motor,

wherein the current value for current flowing through the fan motor is determined based on a value obtained by subtracting the current value of the second detector from the current value of the first detector.