Closed Loop Capacity And Power Management Scheme For Multi Stage Transport Refrigeration System

• US 20150013361A1
• Filed: 03/06/2013
• Published: 01/15/2015
• Est. Priority Date: 03/09/2012
• Status: Active Grant

• Current Assignee: Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Carrier Corporation (Carrier Global Corporation)
• Inventors: Senf, Raymond L. Jr., Stockbridge, Michael, Reason, John R.
• Granted Patent: US 9,908,452 B2
• Time in Patent Office: Days
• US Class Current: 62/118
• CPC Class Codes: B60H 1/3208 Vehicle drive related control of the compressor drive means, e.g. for fuel saving purposes
• CPC Class Codes: B60H 1/3222 characterised by the compressor driving arrangements, e.g. clutches, transmissions or multiple drives B60H1/3208, B60H1/3226 take precedence
• CPC Class Codes: B60H 1/3232 particularly adapted for load transporting vehicles B60H1/3226 takes precedence
• CPC Class Codes: B60P 3/20 Refrigerated goods vehicles air treatment of goods space B60H; air-conditioning means for freight cars, isothermic wagons B61D27/0027; superstructures for refrigerated goods vehicles B62D33/048
• CPC Class Codes: F25B 1/10 with multi-stage compression with cascade operation F25B7/00
• CPC Class Codes: F25B 2327/001 of the internal combustion type
• CPC Class Codes: F25B 2400/13 Economisers
• CPC Class Codes: F25B 2600/0253 with variable speed
• CPC Class Codes: F25B 2600/2509 Economiser valves
• CPC Class Codes: F25B 41/22 between evaporator and compressor
• CPC Class Codes: F25B 49/022 Compressor control arrangements
• CPC Class Codes: F25D 29/003 for movable devices

Abstract

A unit, such as a transport refrigeration unit 12, may include a plurality of components arranged in multiple stages. At least a portion of the components 18,20 may be arranged in a serial or parallel manner. A position associated with the plurality of components may be selected to control a load on a power source, such as an engine 30. For example, a position for each of the components may be selected so as to maximize a delivery of available power from the power source to the unit. In some embodiments, one or more controllers 32,34 may measure a parameter associated with the power source and select a position for one or more of the components. In some embodiments, an economized refrigeration cycle may be used. Capacity may be staged from a single stage compression cycle or mode to a multistage compression cycle or mode, with a corresponding increase in capacity via subcooling.

Claims

1. An apparatus comprising:

a transport refrigeration unit comprising a plurality of valves;

at least one controller configured to measure a parameter associated with an engine,

wherein the at least one controller is configured to dynamically select a position for each of the valves based at least in part on the measured parameter so as to maximize a power provided by the engine to the transport refrigeration unit without exceeding a capacity of the engine, and

wherein the valves are arranged as a plurality of stages.

3. The apparatus of claim 1, wherein the measured parameter comprises at least one of:

a measure of speed of the engine or a position of a rack sensor associated with the engine.

4. The apparatus of claim 1, wherein the unit comprises a refrigeration unit, and wherein the refrigeration unit comprises a compressor, and wherein the selective controlling of the valves comprises selectively controlling an amount of refrigerant provided to the compressor via the valves.

6. The apparatus of claim 1, wherein the selective controlling of the valves comprises a selective setting of a position for each of the valves based on a comparison between the measured parameter and at least one threshold.

7. The apparatus of claim 1, wherein at least two of the valves are arranged in a serial manner with respect to one another.

8. The apparatus of claim 1, wherein the at least one controller is configured to fully engage a first of the plurality of valves prior to at least partially engaging another of the plurality of valves.

9. The apparatus of claim 1, wherein at least two of the plurality of valves are arranged in a parallel manner with respect to one another.

2. (canceled)

5. (canceled)

10. A method comprising:

configuring at least one controller to measure a parameter associated with a power source;

configuring the at least one controller to compare the measured parameter to at least one threshold value; and

configuring the at least one controller to selectively establish a position associated with a plurality of valves arranged as a plurality of stages based at least in part on the comparison.

11. The method of claim 10, wherein the power source comprises an engine, and wherein the measured parameter comprises at least one of:

a measure of speed of the engine in terms of revolutions per minute (RPM) or a level of fuel flow being supplied to the engine relative to a maximum permissible fuel flow.

12. The method of claim 10, further comprising:

configuring the valves to selectively supply refrigerant to a compressor based at least in part on the established position for each valve.

13. The method of claim 10, further comprising:

configuring at least two of the plurality of valves in a serial manner with respect to one another.

14. The method of claim 10, further comprising:

configuring the at least one controller to fully engage a first of the plurality of valves prior to at least partially engaging another of the plurality of valves.

15. The method of claim 10, further comprising:

configuring at least two of the plurality of valves in a parallel manner with respect to one another.

16. The method of claim 15, further comprising:

configuring the at least one controller to associate a first threshold value with a first of the at least two of the plurality of valves; and

configuring the at least one controller to associate a second threshold value with a second of the at least two of the plurality of valves.

17. The method of claim 10, further comprising:

configuring the at least one controller to maximize a delivery of power provided by the power source to a unit associated with the plurality of valves via the selective establishment of the positions associated with the plurality of valves.

18. A system comprising:

a transport refrigeration unit comprising two valves;

an engine; and

at least one controller,

wherein the at least one controller is configured to measure a parameter associated with the engine, and

wherein the measured parameter comprises at least one of;

speed of the engine, a position of a mechanical fuel rack associated with the engine, and a temperature of the engine, and

wherein the at least one controller is configured to dynamically select a position for each of the valves based at least in part on the measured parameter so as to maximize a power provided by the engine to the transport refrigeration unit without exceeding a capacity of the engine, and

wherein the at least one controller is configured to apply hysteresis to the selection of the position for at least one of the valves, and

wherein the valves are arranged as a plurality of stages.

19. The system of claim 18, wherein the valves are arranged in a serial manner with respect to one another, and wherein the at least one controller is configured to:

keep a first of the valves closed until a second of the valves is fully open, and

keep the second of the valves fully open until the position associated with the first of the valves changes from partially open to closed.

20. The system of claim 18, wherein the valves are arranged in a parallel manner with respect to one another, and wherein the position for a first of the two valves is based on a first threshold associated with an overload condition of the engine, and wherein the position for a second of the two valves is based on a second threshold associated with the overload condition of the engine.

21. The system of claim 18, wherein a first of the valves is a suction modulation valve, and wherein a second of the valves is an economizer expansion valve associated with an economizer circuit.

22. The system of claim 18, wherein the two valves operate and communicate via different pressures dictated by a compressor, and wherein the first of the plurality of stages dictates an evaporator mass flow, and wherein a second of the plurality of stages dictates a subcooling potential to an evaporator.