Systems and methods for providing backup energy to a load

• US 7,681,395 B2
• Filed: 08/24/2006
• Issued: 03/23/2010
• Est. Priority Date: 02/05/2003
• Status: Expired due to Fees

• Current Assignee: Active Power Incorporated
• Original Assignee: Active Power Incorporated
• Inventors: Pinkerton, Joseph F, Beatty, David, Perkins, David E
• Primary Examiner(s): Nguyen; Hoang M
• Application Number:
  US11/510,248
• Publication Number:
  US 20070022755A1
• Time in Patent Office: 1,307 Days
• Field of Search: 606/46, 606/57, 606/59
• US Class Current: 60/646
• CPC Class Codes: F02C 6/16 for storing compressed air
• CPC Class Codes: F24F 5/0085 Systems using a compressed air circuit
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02J 9/08 requiring starting of a prime-mover
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies
• CPC Class Codes: Y02E 60/16 Mechanical energy storage, e.g. flywheels or pressurised fluids

Abstract

Backup energy systems utilizing compressed air storage (CAS) systems and bridging energy systems to supply backup power to a load are provided. During a power failure, the bridging energy system provides backup power to the load at least until the CAS system begins supplying adequate power. In various embodiments, backup power capability is enhanced through the use of one or more exhaustless heaters, which are used to heat compressed air. The compressed air, in turn, drives a turbine which is used to power an electrical generator. In various embodiments, ambient air heat exchangers or other types of heat exchangers are used to heat compressed air prior to the compressed air being routed to the turbine, thereby increasing system efficiency. Backup power and backup HVAC are also provided by utilizing turbine exhaust, heat exchangers and various resistive heating elements.

Claims

1. An apparatus comprising:

a source of short-term backup power for providing backup power to a critical load, the critical load located inside a housing, and the housing having an internal temperature;

a compressed air reservoir for storing compressed air;

at least one valve coupled to the compressed air reservoir;

an ambient air heat exchanger coupled to the at least one valve;

a compressed air turbine coupled to the at least one valve to receive the compressed air and release a turbine exhaust; and

an electrical generator powered by the turbine, for providing backup power to the critical load.

2. The apparatus of claim 1, wherein:

the compressed air reservoir is a replaceable compressed air tank.

3. The apparatus of claim 1, wherein:

the ambient air heat exchanger includes at least one fan.

4. The apparatus of claim 3, wherein:

the fan is a variable-speed fan, the speed of the fan depending on the internal temperature of the housing.

5. The apparatus of claim 1, further comprising:

a compressor coupled to the at least one valve for filling the compressed air reservoir with compressed air;

wherein the compressor has a motor.

6. The apparatus of claim 1, further comprising:

at least one thermal storage unit coupled between the compressed air reservoir and the turbine to heat the compressed air.

7. An apparatus comprising:

a source of short-term backup power for providing backup power to a critical load, the critical load located inside a housing, and the housing having an internal temperature;

a compressed air reservoir for storing compressed air;

at least one valve coupled to the compressed air reservoir;

a compressed air turbine coupled to the at least one valve to receive the compressed air and release a turbine exhaust into the housing; and

an electrical generator powered by the turbine, for providing backup power to the critical load.

8. The apparatus of claim 7, wherein:

the compressed air reservoir is a replaceable compressed air tank.

9. The apparatus of claim 7, further comprising:

a compressor coupled to the at least one valve for filling the compressed air reservoir with compressed air, wherein the compressor has a motor.

10. The apparatus of claim 7, further comprising:

at least one thermal storage unit coupled between the compressed air reservoir and the turbine to heat the compressed air.

11. The apparatus of claim 10, further comprising:

a bypass valve for allowing at least a portion of the compressed air to bypass the at least one thermal storage unit.

12. The apparatus of claim 7, further comprising:

a resistive circuit located outside the housing and electrically coupled to the electrical generator, the resistive circuit selectively dissipating electrical power from the electrical generator based on the internal temperature of the housing to lower the internal temperature of the housing.

13. The apparatus of claim 7, further comprising:

a resistive circuit located inside the housing and electrically coupled to the electrical generator, the resistive circuit selectively dissipating electrical power from the electrical generator based on the internal temperature of the housing to raise the internal temperature of the housing.

14. An apparatus comprising:

a compressed air reservoir for storing compressed air;

at least one valve coupled to the compressed air reservoir;

a compressed air turbine coupled to the at least one valve to receive the compressed air and release a turbine exhaust;

an electrical generator powered by the turbine, for providing backup power to a critical load located inside a housing, the housing having an internal temperature; and

a fan associated with the compressed air reservoir to move cool air from near the compressed air reservoir to lower the internal temperature of the housing.

15. The apparatus of claim 14, wherein:

the compressed air reservoir is a replaceable compressed air tank.

16. The apparatus of claim 14, further comprising:

a compressor coupled to the at least one valve for filling the compressed air reservoir with compressed air, wherein the compressor has a motor.

17. The apparatus of claim 14, wherein:

the fan is a variable-speed fan, the speed of the fan depending on the internal temperature of the housing.

18. The apparatus of claim 14, wherein:

the at least one valve is capable of releasing at least a portion of the compressed air into the housing based on the internal temperature of the housing.

19. The apparatus of claim 14, further comprising:

a reservoir heat exchanger coupled between the compressed air reservoir and the turbine to heat the compressed air before it reaches the turbine.

20. The apparatus of claim 19, further comprising:

a turbine exhaust heat exchanger coupled to the turbine exhaust to cool the turbine exhaust; and

a pump coupled between the reservoir heat exchanger and the turbine exhaust heat exchanger.