Refrigeration unit and diagnostic method therefor

• US 7,765,818 B2
• Filed: 05/30/2006
• Issued: 08/03/2010
• Est. Priority Date: 05/30/2006
• Status: Active Grant

• Current Assignee: B/E Aerospace, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: B/E Aerospace, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Buck, Gilbert Walter
• Primary Examiner(s): Denion; Thomas E
• Assistant Examiner(s): Carton; Michael
• Application Number:
  US11/443,557
• Publication Number:
  US 20070277538A1
• Time in Patent Office: 1,526 Days
• Field of Search: 621/25, 621/26, 621/27, 621/28, 621/29, 621/30, 621/31, 621/57, 622/03, 622/31
• US Class Current: 62/180
• 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 therefore 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 operative to output data relative to the vapor cycle system; and

a controller comprising;

an input module that receives, the data from the plurality of sensors,

a processor communicatively coupled with the input module and operative to process the data from the plurality of sensors to determine an occurrence of an event related to the data from the plurality of sensors and effect a plurality of control and informational outputs relative to the data from the plurality of sensors,

an output module communicatively coupled with the processor and operative to output control signals to the vapor cycle system as effected by the processor, and

a memory module communicatively coupled with the processor, the memory module including a history log data structure to which the data from the plurality of sensors is logged as effected by the processor according to a first data-logging mode, and to which the data from the plurality of sensors is logged as effected by the processor according to a second data-logging mode upon occurrence of the event related to the data from the plurality of sensors as determined by the processor,

wherein the first data-logging mode comprises the controller logging the data from the plurality of sensors at a first data-logging rate and the second data-logging mode comprises the controller logging the data from the plurality of sensors at a second data-logging rate different from the first data-logging rate.

2. The refrigeration unit of claim 1 wherein the second data-logging rate comprises a one-time logging of the data substantially simultaneously with the occurrence of the event.

3. 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.

4. The refrigeration unit of claim 3 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.

5. 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.

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

7. The refrigeration unit of claim 4 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.

8. 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 insulated cavity.

9. The refrigeration unit of claim 8 wherein the user interface further comprises a warning device, the warning device operative to output an alert when the controller detects a difference between a temperature sensed in the insulated cavity and the temperature set point.

15. The refrigeration unit of claim 1 wherein the event is selected from the group consisting of a warning event, a fault event, and an informational event.

16. The refrigeration unit of claim 1 wherein while the event persists, the controller continues to log the data to the history log data structure at the second data-logging rate, and after the event ends, the controller returns to logging the data to the history log data structure at the first data-logging rate.

17. The refrigeration unit of claim 1 wherein the first data-logging rate is a fixed rate at which data entries of the data from the plurality of sensors are written to the history log data structure and the second data-logging rate is a different rate at which data entries of the data from the plurality of sensors are written to the history log data structure compared to the fixed first data-logging rate.

10. 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, the door operative to move 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 operative to detect the open orientation and output 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 operative to output at least temperature and pressure data relative to the vapor cycle system; and

a controller comprising;

an input module that receives the door signal from the door sensor and the at least temperature and pressure data from the plurality of sensors in communication with the vapor cycle system,

a processor communicatively coupled with the input module and operative to determine an occurrence of an event related to the door signal and the at least temperature and pressure data and effect a plurality of control and informational outputs relative to the door signal and the at least temperature and pressure data,

an output module communicatively coupled with the processor and operative to output control signals to the vapor cycle system as effected by the processor, and

a memory module communicatively coupled with the processor, the memory module including a history log data structure to which the controller logs the at least temperature and pressure data at a first data-logging rate, and to which the controller logs the at least temperature and pressure data at a second data-logging rate upon occurrence of the event related to the door signal and the at least temperature and pressure data as determined by the processor,

wherein the second data-logging rate is different from the first data-logging rate.

11. The refrigeration LRU of claim 10 wherein the vapor cycle system comprises:

a compressor unit including a compressor motor and a compressor sensor, the compressor sensor operative to detect a rotational speed of the compressor motor;

a condenser unit including a condenser motor and a condenser sensor, the condenser sensor operative to detect 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 operative to detect 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.

12. The refrigeration LRU of claim 10 further comprising a user interface in communication with the controller, the user interface operative to set a temperature set point for the insulated cavity.

13. The refrigeration LRU of claim 12 wherein the user interface further comprises a warning device, the warning device operative to an alert when the controller detects a difference between a temperature sensed in the insulated cavity and the temperature set point.

14. The refrigeration LRU of claim 11 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.

18. The refrigeration LRU of claim 10 wherein the event is selected from the group consisting of a warning event, a fault event, and an informational event.

19. The refrigeration LRU of claim 10 wherein while the event persists, the controller continues to log the at least temperature and pressure data to the history log data structure at the second data-logging rate, and after the event ends, the controller returns to logging the at least temperature and pressure data to the history log data structure at the first data-logging rate.

20. The refrigeration LRU of claim 10 wherein the first data-logging rate is a fixed rate at which data entries of the at least temperature and pressure data from the plurality of sensors are written to the history log data structure and the second data-logging rate is a different rate at which data entries of the at least temperature and pressure data from the plurality of sensors are written to the history log data structure compared to the fixed first data-logging rate.