Air Cycle Machine Pack System and Method for Improving Low Inlet Pressure Cooling Performance

• US 20150166187A1
• Filed: 12/13/2013
• Published: 06/18/2015
• Est. Priority Date: 12/13/2013
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Durbin, Richard R., FITERMAN, Charles J., Sullivan, Daniel J.
• Granted Patent: US 9,656,755 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B64D 13/08 the air being heated or cooled
• CPC Class Codes: B64D 2013/0618 with arrangements for reducing or managing bleed air, using another air source, e.g. ram air
• CPC Class Codes: Y02T 50/50 On board measures aiming to increase energy efficiency

Abstract

An air cycle machine (ACM) pack system for an aircraft with an improved low inlet pressure cooling performance is provided. The ACM pack system has an air cycle machine (ACM) with at least one compressor mechanically coupled to at least one turbine in series on an ACM shaft. The ACM pack system further has a pack heat exchanger coupled to and in fluid communication with the at least one compressor of the ACM. The ACM system further has a bypass air flow assembly coupled in a parallel operation path to the ACM and has a bypass air flow regulating element. The bypass air flow assembly transfers energy extracted by the bypass air flow assembly to the ACM to aid the ACM pack system in cooling performance at a low inlet pressure, resulting in an improved low inlet pressure cooling performance of the ACM pack system.

Claims

1. An air cycle machine (ACM) pack system for an aircraft, the system having an improved low inlet pressure cooling performance, the system comprising:

an air cycle machine (ACM) comprising at least one compressor mechanically coupled to at least one turbine in series on an ACM shaft;

a pack heat exchanger coupled to and in fluid communication with the at least one compressor of the ACM; and

,

a bypass air flow assembly coupled in a parallel operation path to the ACM, the bypass air flow assembly having a bypass air flow regulating element,

wherein the bypass air flow assembly transfers energy extracted by the bypass air flow assembly to the ACM to aid the air cycle machine (ACM) pack system in cooling performance at a low inlet pressure, resulting in an improved low inlet pressure cooling performance of the air cycle machine (ACM) pack system.

2. The system of claim 1 wherein the air cycle machine (ACM) comprises a three wheel pack having one compressor mechanically coupled in series to one turbine on the ACM shaft.

3. The system of claim 2 wherein the bypass air flow assembly comprises a parallel turbine coupled to a turbine shaft, and a mechanical drive element connecting the turbine shaft to the ACM shaft to drive the turbine of the ACM and the turbine of the bypass air flow assembly in the parallel operation path.

4. The system of claim 3 wherein the mechanical drive element comprises a mechanical shaft or a geared shaft.

5. The system of claim 3 wherein the bypass air flow regulating element comprises a parallel turbine valve coupled to the parallel turbine.

6. The system of claim 2 wherein the bypass air flow assembly comprises a turbo-compressor assembly coupled to a regeneration heat exchanger and a check valve, all coupled to the ACM, and the flow regulating element comprises a parallel turbine valve coupled to the turbo-compressor assembly.

7. The system of claim 1 wherein the air cycle machine (ACM) comprises a four wheel pack with a compressor, a first turbine and a second turbine mechanically coupled in series on the ACM shaft.

8. The system of claim 7 wherein the bypass air flow regulating element comprises a parallel turbine valve coupled between the first turbine and the second turbine.

9. The system of claim 8 wherein the bypass air flow assembly comprises a parallel turbine valve assembly coupled to the ACM, the parallel turbine valve assembly comprising a compressor bypass valve, an isolation valve, a check valve, and the parallel turbine valve.

10. The system of claim 1 wherein the bypass air flow assembly is either a mechanical energy transfer bypass air flow assembly or a pneumatic energy transfer bypass air flow assembly.

11. An aircraft comprising:

one or more aircraft engines each having a bleed air system for generating bleed air;

a fuselage defining an interior volume having an aircraft cabin and a pack bay separate from the aircraft cabin;

an aircraft air conditioning system positioned in the pack bay and in fluid communication with the aircraft cabin, the aircraft air conditioning system having an air cycle machine (ACM) pack system comprising;

an air cycle machine (ACM) comprising at least one compressor mechanically coupled to at least one turbine in series on an ACM shaft;

a pack heat exchanger coupled to and in fluid communication with the at least one compressor of the ACM; and

,

a bypass air flow assembly coupled in a parallel operation path to the ACM, the bypass air flow assembly having a parallel turbine valve,

wherein the bypass air flow assembly transfers energy extracted by the bypass air flow assembly to the ACM to aid the ACM pack system in cooling performance at a low inlet pressure, resulting in an improved low inlet pressure cooling performance of the ACM pack system.

12. The aircraft of claim 11 wherein the air cycle machine (ACM) comprises a three wheel pack having one compressor mechanically coupled in series to one turbine on the ACM shaft.

13. The aircraft of claim 12 wherein the bypass air flow assembly comprises a parallel turbine coupled to a turbine shaft, and a mechanical drive element connecting the turbine shaft to the ACM shaft to drive the turbine of the ACM and the turbine of the bypass air flow assembly in the parallel operation path and to transfer mechanical energy from the bypass air flow assembly to the ACM.

14. The aircraft of claim 12 wherein the bypass air flow assembly comprises a turbo-compressor assembly coupled to a regeneration heat exchanger and a check valve, all coupled to the ACM, and the parallel turbine valve is coupled to the turbo-compressor assembly, the turbo-compressor assembly transferring pneumatic energy from the bypass air flow assembly to the ACM.

15. The aircraft of claim 11 wherein the air cycle machine (ACM) comprises a four wheel pack with a compressor, a first turbine, and a second turbine mechanically coupled in series on the ACM shaft.

16. The aircraft of claim 15 wherein the bypass air flow assembly comprises a parallel turbine valve assembly coupled to the ACM, the parallel turbine valve assembly comprising a compressor bypass valve, an isolation valve, a check valve, and the parallel turbine valve, the parallel turbine valve assembly transferring mechanical energy from the bypass air flow assembly to the ACM.

17. A method for improving low inlet pressure cooling performance of an air cycle machine (ACM) pack system, the method comprising the steps of:

installing an air cycle machine (ACM) pack system in an aircraft air conditioning system of an aircraft, the ACM pack system comprising;

an air cycle machine (ACM) comprising at least one compressor mechanically coupled to at least one turbine in series on an ACM shaft;

a pack heat exchanger coupled to and in fluid communication with the at least one compressor of the ACM; and

,

a bypass air flow assembly configured for coupling to the ACM and having a bypass air flow regulating element,

coupling the bypass air flow assembly and the ACM in a parallel operation path;

using the bypass air flow assembly to extract energy from a bypass air flow flowing across the bypass air flow assembly to obtain extracted energy;

transferring the extracted energy from the bypass air flow assembly to the ACM to aid the air cycle machine (ACM) pack system in cooling performance at a low inlet pressure, resulting in an improved low inlet pressure cooling performance of the air cycle machine (ACM) pack system.

18. The method of claim 17 wherein the transferring step comprises either transferring mechanical energy from the bypass air flow assembly to the ACM, or transferring pneumatic energy from the bypass air flow assembly to the ACM.

19. The method of claim 17 wherein the installing step further comprises installing an air cycle machine (ACM) comprising a three wheel pack having one compressor mechanically coupled in series to one turbine on the ACM shaft.

20. The method of claim 19 wherein the installing step further comprises installing the bypass air flow assembly comprising a parallel turbine coupled to a turbine shaft, and a mechanical drive element connecting the turbine shaft to the ACM shaft to drive the turbine of the ACM and the turbine of the bypass air flow assembly in the parallel operation path and to transfer mechanical energy from the bypass air flow assembly to the ACM.

21. The method of claim 19 wherein the installing step further comprises installing the bypass air flow assembly comprising a turbo-compressor assembly coupled to a regeneration heat exchanger and a check valve, all coupled to the ACM, and coupling the flow regulating element comprising a parallel turbine valve to the turbo-compressor assembly.

22. The method of claim 17 wherein the installing step further comprises installing an air cycle machine (ACM) comprising a four wheel pack with a compressor, a first turbine, and a second turbine mechanically coupled in series on the ACM shaft.

23. The method of claim 22 wherein the installing step further comprises installing the bypass air flow assembly comprising a parallel turbine valve assembly coupled to the ACM, the parallel turbine valve assembly comprising a compressor bypass valve, an isolation valve, a check valve, and the bypass air flow regulating element comprising a parallel turbine valve, the parallel turbine valve assembly transferring mechanical energy from the bypass air flow assembly to the ACM.