Refrigeration unit and diagnostic method therefor

• US 20070277538A1
• Filed: 05/30/2006
• Published: 12/06/2007
• Est. Priority Date: 05/30/2006
• Status: Active Grant

• Current Assignee: B/E Aerospace, Inc. (Rtx Corporation)
• Original Assignee: B/E Aerospace, Inc. (Rtx Corporation)
• Inventors: Buck, Gilbert Walter
• Granted Patent: US 7,765,818 B2
• Time in Patent Office: Days
• US Class Current: 62/150
• CPC Class Codes: F25B 49/005 of safety devices F25B49/02 and F25B49/04 take precedence
• CPC Class Codes: F25D 2400/361 Interactive visual displays
• CPC Class Codes: F25D 2700/02 Sensors detecting door opening
• CPC Class Codes: F25D 29/003 for movable devices

Abstract

A refrigeration unit and diagnostic method therefor are provided. The refrigeration unit includes: a housing with an insulated cavity for storing food and beverages; a vapor cycle system operative to cool the food and beverages in the insulated cavity; a plurality of sensors in communication with the vapor cycle system and outputting data relative to the vapor cycle system; and a controller that, according to the data from the plurality of sensors, determines an occurrence of an event. Wherein the controller logs the data from the plurality of sensors to a data structure according to a first data-logging mode, and logs the data to the data structure according to a second data-logging mode upon occurrence of the event. In one embodiment the refrigeration unit may be a refrigeration line replaceable unit (LRU) configured for an aircraft galley.

Claims

1. A refrigeration unit comprising:

a housing including an insulated cavity configured to store food and beverages;

a vapor cycle system disposed in the housing, the vapor cycle system operative to cool the food and beverages in the insulated cavity;

a plurality of sensors disposed in the housing, the plurality of sensors in communication with the vapor cycle system and outputting data relative to the vapor cycle system; and

a controller, according to the data from the plurality of sensors, determining an occurrence of an event and outputting control signals to the vapor cycle system, and wherein the controller logs the data to a data structure according to a first data-logging mode, and to the data structure according to a second data-logging mode upon occurrence of the event.

2. The refrigeration unit of claim 1 wherein the first data-logging mode comprises a first data-logging rate and the second data-logging mode comprises a second data-logging rate different from the first data-logging rate.

3. The refrigeration unit of claim 2 wherein the second data-logging rate comprises a one-time logging of the data substantially simultaneously with the occurrence of the event.

4. The refrigeration unit of claim 1 wherein the vapor cycle system comprises:

a compressor unit;

a condenser unit including a condenser fan; and

an evaporator unit including an evaporator fan,

wherein the controller is operative to reverse a direction of the evaporator fan to defrost the vapor cycle system.

5. The refrigeration unit of claim 4 wherein the plurality of sensors comprises:

at least one temperature sensor disposed in an airflow of at least one of the condenser fan and the evaporator fan; and

at least one pressure sensor.

6. The refrigeration unit of claim 4 wherein the at least one temperature sensor comprises:

an intake air temperature sensor;

an exhaust air temperature sensor;

a supply air temperature sensor at an outlet of the evaporator unit; and

a return air temperature sensor at an inlet of the evaporator unit.

7. The refrigeration unit of claim 5 wherein the at least one temperature sensor comprises a thermistor.

8. The refrigeration unit of claim 5 wherein the at least one pressure sensor comprises:

a first pressure transducer configured at a refrigerant inlet of the compressor; and

a second pressure transducer configured at a refrigerant outlet of the condenser unit.

9. The refrigeration unit of claim 1 further comprising a user interface in communication with the controller, the user interface operative to set a temperature set point for the internal cavity.

10. The refrigeration unit of claim 9 wherein the user interface further comprises a warning device, the warning device outputting an alert when the controller detects a difference between a temperature being sensed in the internal cavity and the temperature set point.

11. A diagnostic method for a refrigeration unit including a plurality of sensors and a controller, the method comprising:

the controller, receiving data from the plurality of sensors;

the controller, determining an occurrence of an event relative to the data received from the plurality of sensors;

if an event has not occurred, the controller, storing the data to a data structure according to a first data-logging mode; and

if an event has occurred, the controller, storing the data to the data structure according to a second data-logging mode different from the first data-logging mode.

12. The method of claim 11 wherein the determining step comprises:

detecting a warning event;

detecting a fault event; and

detecting an informational event.

13. The method of claim 12 wherein the step of storing the data to the data structure according to a second data-logging mode comprises setting a data-storage rate.

14. The method of claim 12 wherein the step of detecting a warning event comprises:

the controller, receiving at least one of temperature and pressure data from the plurality of sensors; and

the controller, comparing the at least one of temperature and pressure data with predetermined normal temperature and pressure values.

15. The method of claim 14 wherein the step of detecting a warning event further comprises providing a warning indication if the at least one of temperature and pressure data exceeds the predetermined normal temperature and pressure values.

16. The method of claim 12 wherein the step of detecting a fault event comprises:

the controller, receiving status data relative to a plurality of components within the refrigeration unit from the plurality of sensors;

the controller, comparing the status data with predetermined normal status values within the refrigeration unit.

17. The method of claim 16 wherein the status data comprises motor speed data.

18. The method of claim 12 wherein the step of detecting an informational event comprises:

determining an orientation of a door configured to seal an interior of the refrigeration unit; and

the controller, determining receipt of a signal from an actuator of a user interface.

19. A refrigeration line replaceable unit (LRU) for an aircraft galley, the refrigeration LRU comprising:

a housing including an insulated cavity configured to store food and beverages;

a door coupled with the housing for movement between an open orientation for accessing the food and beverages and a closed orientation for sealing the food and beverages in the insulated cavity;

a door sensor detecting the open orientation and outputting a door signal relative to the open orientation;

a vapor cycle system operative to cool the food and beverages in the insulated cavity;

a plurality of sensors in communication with the vapor cycle system, the plurality of sensors outputting at least temperature and pressure data relative to the vapor cycle system; and

a controller, according to the door signal and the at least temperature and pressure data, determining an occurrence of an event and outputting control signals to the vapor cycle system, and

wherein the controller logs the at least temperature and pressure data to a data structure at a first rate, and to the data structure at a second rate upon occurrence of the event.

20. The refrigeration LRU of claim 19 wherein the vapor cycle system comprises:

a compressor unit including a compressor motor and a compressor sensor, the compressor sensor detecting a rotational speed of the compressor motor;

a condenser unit including a condenser motor and a condenser sensor, the condenser sensor detecting at least one of a rotational direction and a rotational speed of the condenser motor; and

an evaporator unit including an evaporator motor and an evaporator sensor, the evaporator sensor detecting at least one of a rotational direction and a rotational speed of the evaporator motor, and

wherein the controller is operative to reverse the rotational direction of the evaporator motor to defrost the vapor cycle system.

21. The refrigeration LRU of claim 19 further comprising a user interface in communication with the controller, the user interface operative to set a temperature set point for the internal cavity.

22. The refrigeration LRU of claim 21 wherein the user interface further comprises a warning device, the warning device outputting an alert when the controller detects a difference between a temperature being sensed in the internal cavity and the temperature set point.

23. The refrigeration LRU of claim 20 wherein the plurality of sensors comprises:

an intake air temperature sensor;

an exhaust air temperature sensor;

a supply air temperature sensor at an outlet of the evaporator unit; and

a return air temperature sensor at an inlet of the evaporator unit.

24. A diagnostic method for a refrigeration unit including a plurality of sensors and a controller, the method comprising:

the controller, operating in a normal data-logging mode;

the controller, receiving data from the plurality of sensors;

the controller, determining an occurrence of at least one of a warning event, a fault event and an informational event relative to the data received from the plurality of sensors;

according to the determining step, if the warning event has occurred, the controller operating in a warning data-logging mode different from the normal data-logging mode;

according to the determining step, if the fault event has occurred, the controller operating in a fault data-logging mode different from the normal data-logging mode;

according to the determining step, if the informational event has occurred, the controller operating in an informational data-logging mode different from the normal data-logging mode; and

if an event has occurred, the controller, storing the data to the data structure according to a second data-logging mode different from the first data-logging mode.

25. The method of claim 24 further comprising:

the controller, determining an end of the occurrence of at least one of the warning event, the fault event and the informational event relative to the data received from the plurality of sensors; and

the controller, switching from at least one of the warning data-logging mode, the fault data-logging mode, and the informational data-logging mode to the normal data-logging mode.

26. The method of claim 24 wherein the step of operating in the warning data-logging mode further comprises the step of setting a warning data-logging rate, wherein the step of operating in the fault data-logging mode further comprises the step of setting a fault data-logging rate, and wherein the step of operating in the informational data-logging mode further comprises the step of setting an informational data-logging rate.

27. The method of claim 26 wherein at least one of the steps of setting the warning data-logging rate, setting the fault data-logging rate, and setting the informational data-logging rate comprises the step of one-time logging of the data substantially simultaneously with the occurrence of the event.