METHOD AND SYSTEM FOR CONVERTING WASTE HEAT FROM CEMENT PLANT INTO A USABLE FORM OF ENERGY

• US 20100122533A1
• Filed: 11/20/2008
• Published: 05/20/2010
• Est. Priority Date: 11/20/2008
• Status: Active Grant

• Current Assignee: Kalina Power Limited
• Original Assignee: Kalex, LLC
• Inventors: Kalina, Alexander I.
• Granted Patent: US 8,176,738 B2
• Time in Patent Office: Days
• US Class Current: 60/645
• CPC Class Codes: C04B 7/43 Heat treatment, e.g. precalcining, burning, melting; Cooling aspects only relating to the installation F27B
• CPC Class Codes: C04B 7/475 using the waste heat, e.g. of the cooled clinker, in an other way than by simple heat exchange in the cement production line, e.g. for generating steam
• CPC Class Codes: F01K 25/06 using mixtures of different fluids plants using mixtures of steam and gas F01K21/04
• CPC Class Codes: F01K 25/10 the vapours being cold, e.g. ammonia, carbon dioxide, ether
• CPC Class Codes: F22B 1/18 the heat carrier being a hot gas, e.g. waste gas such as exhaust gas of internal-combustion engines use of waste heat of combustion engines, in general, F02G
• CPC Class Codes: Y02P 40/121 Energy efficiency measures, e.g. improving or optimising the production methods

Abstract

Methods and systems for converting waste heat from cement plant into a usable form of energy are disclosed. The methods and systems make use of two heat source streams from the cement plant, a hot air stream and a flue gas stream, to fully vaporize and superheat a working fluid stream, which is then used to convert a portion of its heat to a usable form of energy. The methods and systems utilize sequential heat exchanges stages to heat the working fluid stream, first with the hot air stream or from a first heat transfer fluid stream heated by the hot air stream and second with the flue gas stream from a second heat transfer fluid stream heated by the hot air stream.

Claims

1. A power extraction system comprising:

a cement plant producing a hot air stream and a flue gas stream;

a heat exchange apparatus including;

a first heat exchange stage adapted to heat a fully condensed, multi-component working fluid stream in counterflow with a first heat source stream to form a partially vaporized, multi-component working fluid stream and a cooled first heat source stream; and

a second heat exchange stage adapted to heat the partially vaporized, multi-component working fluid stream in counterflow with a second heat source stream to form a fully vaporized and superheated, working fluid stream and a cooled second heat source stream;

a power plant including;

an energy extraction unit adapted to convert a portion of thermal energy in the fully vaporized and superheated, working fluid stream into a usable form of energy and to form a spent, multi-component working fluid stream; and

a condensation unit adapted to condense the spent, multi-component working fluid stream thermal to form the fully condensed, multi-component working fluid stream.

2. The system of claim 1, wherein the first heat source stream is the hot air stream and the cooled flue gas stream is returned to the cement plant to preheat materials for use in the cement plant and/or the second heat source stream is the flue stream and the cooled flue gas stream is returned to the cement plant to preheat materials for use in the cement plant.

3. The system of claim 1, wherein the condensation unit preheats the fully condensed working fluid stream.

4. The system of claim 1, wherein the condensation unit comprises a simple condenser, a distillation-condensation subsystem DCSS or a condensation thermal compression subsystem CTCSS preheats the fully condensed working fluid stream.

5. The system of claim 1, further comprising:

a particulate separation and heat transfer subsystem including;

a hot air particulate separation and heat transfer unit adapted to heat a first high temperature heat transfer fluid stream with the hot air stream to form a heated first high temperature heat transfer fluid stream and the cooled air stream,

where the first heat source stream is the heated first high temperature heat transfer fluid stream and the second heat source stream is the flue gas stream.

6. The system of claims 5, wherein each particulate separation and heat transfer unit comprises:

a large particle separator adapted to remove substantially all large particles from either the hot air stream or the flue gas stream,

a scrubber adapted to heat the heat transfer fluid streams with heat from the hot air stream or the flue gas,

a pump adapted to circulated the heated heat transfer fluid streams into the heat exchange unit, and

a filter for removing the dust from the transfer fluid streams or the hot air streams or the flue gas stream so that the streams going to the heat exchange unit are substantially dust free.

7. The system of claim 1, further comprising:

a particulate separation and heat transfer subsystem including;

a flue gas particulate separation and heat transfer unit adapted to heat a second high temperature heat transfer fluid stream with the flue gas stream to form a heated second high temperature heat transfer fluid stream and the cooled flue gas stream,

where the first heat source stream is the hot air stream and the second heat source stream is the heated second high temperature heat transfer fluid stream.

8. The system of claims 7, wherein each particulate separation and heat transfer unit comprises:

a large particle separator adapted to remove substantially all large particles from either the hot air stream or the flue gas stream,

a scrubber adapted to heat the heat transfer fluid streams with heat from the hot air stream or the flue gas,

a pump adapted to circulated the heated heat transfer fluid streams into the heat exchange unit, and

a filter for removing the dust from the transfer fluid streams or the hot air streams or the flue gas stream so that the streams going to the heat exchange unit are substantially dust free.

9. The system of claim 1, further comprising:

a particulate separation and heat transfer subsystem including;

a hot air particulate separation and heat transfer unit adapted to heat a first high temperature heat transfer fluid stream with the hot air stream to form a heated first high temperature heat transfer fluid stream and the cooled air stream,

a flue gas particulate separation and heat transfer unit adapted to heat a second high temperature heat transfer fluid stream with the flue gas stream to form a heated second high temperature heat transfer fluid stream and the cooled flue gas stream,

where the first heat source stream is the heated first high temperature heat transfer fluid stream and the second heat source stream is the heated second high temperature heat transfer fluid stream.

10. The system of claims 9, wherein each particulate separation and heat transfer unit comprises:

a large particle separator adapted to remove substantially all large particles from either the hot air stream or the flue gas stream,

a scrubber adapted to heat the heat transfer fluid streams with heat from the hot air stream or the flue gas,

a pump adapted to circulated the heated heat transfer fluid streams into the heat exchange unit, and

a filter for removing the dust from the transfer fluid streams or the hot air streams or the flue gas stream so that the streams going to the heat exchange unit are substantially dust free.

11. A method for producing usable energy from heat sources stream derived from a cement plant comprising:

supplying a hot air stream and a flue gas stream from a cement plant,

heating a fully condensed, multi-component working fluid stream with the heat derived directly or indirectly from the hot air stream in a first stage of a heat exchange unit to form a partially vaporized, multi-component working fluid stream and a cooled air stream,

heating the partially vaporized, multi-component working fluid stream with the heat derived directly or indirectly from the flue gas stream in a second stage of the heat exchange unit to form a fully vaporized and superheated, multi-component working fluid stream and a cooled flue gas stream,

converting a portion of thermal energy in the fully vaporized and superheated, multi-component working fluid stream to a usable form of energy to form a spent, multi-component working fluid stream, and

condensing the spent, multi-component working fluid stream to form the fully condensed, multi-component working fluid stream.

12. The method of claim 11, further comprising:

returning the cooled air stream to the cement plant, and/or

returning the cooled flue gas stream to the cement plant.

13. The method of claim 11, further comprising:

passing the hot air stream through a large particle separator of a particulate separation and heat transfer subsystem to form a dust laden hot air stream,

transferring heat from the dust laden hot air stream to a first high temperature heat transfer fluid stream in a scrubber to form the cooled air stream and a heated first high temperature heat transfer fluid stream,

pressurizing the heated first high temperature heat transfer fluid stream to form a higher pressure, heated first high temperature heat transfer fluid stream, and

filtering the higher pressure, heated first high temperature heat transfer fluid stream to form a substantially dust free, higher pressure, heated first high temperature heat transfer fluid stream, which is used to partially vaporize the fully condensed, multi-component working fluid stream in the first stage of the heat exchange unit.

14. The method of claim 11, further comprising:

passing the flue gas stream through a large particle separator of a particulate separation and heat transfer subsystem to form a dust laden flue gas stream,

transferring heat from the dust laden flue gas stream to a second high temperature heat transfer fluid stream in a scrubber to form the cooled flue gas stream and a heated second high temperature heat transfer fluid stream,

pressurizing the heated second high temperature heat transfer fluid stream to form a higher pressure, heated second high temperature heat transfer fluid stream, and

filtering the higher pressure, heated second high temperature heat transfer fluid stream to form a substantially dust free, higher pressure, heated second high temperature heat transfer fluid stream, which is used to fully vaporize and superheat the partially vaporized, multi-component working fluid stream in the second stage of the heat exchange unit.

15. The method of claim 11, further comprising:

passing the hot air stream through a first large particle separator of a particulate separation and heat transfer subsystem to form a dust laden hot air stream,

transferring heat from the dust laden hot air stream to a first high temperature heat transfer fluid stream in a first scrubber to form the cooled air stream and a heated first high temperature heat transfer fluid stream,

pressurizing the heated first high temperature heat transfer fluid stream to form a higher pressure, heated first high temperature heat transfer fluid stream,

filtering the higher pressure, heated first high temperature heat transfer fluid stream to form a substantially dust free, higher pressure, heated first high temperature heat transfer fluid stream, which is used to partially vaporize the fully condensed, multi-component working fluid stream in the first stage of the heat exchange unit,

passing the flue gas stream through a second large particle separator of a particulate separation and heat transfer subsystem to form a dust laden flue gas stream,

transferring heat from the dust laden flue gas stream to a second high temperature heat transfer fluid stream in a second scrubber to form the cooled flue gas stream and a heated second high temperature heat transfer fluid stream,

pressurizing the heated second high temperature heat transfer fluid stream to form a higher pressure, heated second high temperature heat transfer fluid stream, and

filtering the higher pressure, heated second high temperature heat transfer fluid stream to form a substantially dust free, higher pressure, heated second high temperature heat transfer fluid stream, which is used to fully vaporize and superheat the partially vaporized, multi-component working fluid stream in the second stage of the heat exchange unit.

16. The method of claim 11, further comprising:

passing the hot air stream through a large particle separator of a particulate separation and heat transfer subsystem to form a dust laden hot air stream,

pressurizing the dust laden hot air stream to form a higher pressure, dust laden hot air stream,

filtering the higher pressure, dust laden hot air stream to form a substantially dust free, higher pressure, hot air stream, and

transferring heat from the substantially dust free, higher pressure, hot air stream to a first high temperature heat transfer fluid stream in a scrubber to form the cooled air stream and a heated first high temperature heat transfer fluid stream, which is used to partially vaporize the fully condensed, multi-component working fluid stream in the first stage of the heat exchange unit.

17. The method of claim 16, further comprising:

pressurizing the heated first high temperature heat transfer fluid stream to form a higher pressure, heated first high temperature heat transfer fluid stream, before being forwarded to the first stage of the heat exchange unit.

18. The method of claim 11, further comprising:

passing the flue gas stream through a large particle separator of a particulate separation and heat transfer subsystem to form a dust laden flue gas stream,

pressurizing the dust laden flue gas stream to form a higher pressure, dust laden flue gas stream,

filtering the higher pressure, dust laden flue gas stream to form a substantially dust free, higher pressure, flue gas stream, and

transferring heat from the substantially dust free, higher pressure, flue gas stream to a second high temperature heat transfer fluid stream in a scrubber to form the cooled flue gas stream and a heated second high temperature heat transfer fluid stream, which is used to fully vaporize and superheat the partially vaporized, multi-component working fluid stream in the second stage of the heat exchange unit.

19. The method of claim 18, further comprising:

pressurizing the heated second high temperature heat transfer fluid stream to form a higher pressure, heated second high temperature heat transfer fluid stream, before being forwarded to the second stage of the heat exchange unit.

20. The method of claim 11, further comprising:

passing the hot air stream through a large particle separator of a particulate separation and heat transfer subsystem to form a dust laden hot air stream,

pressurizing the dust laden hot air stream to form a higher pressure, dust laden hot air stream,

filtering the higher pressure, dust laden hot air stream to form a substantially dust free, higher pressure, hot air stream,

transferring heat from the substantially dust free, higher pressure, hot air stream to a first high temperature heat transfer fluid stream in a scrubber to form the cooled air stream and a heated first high temperature heat transfer fluid stream, which is used to partially vaporize the fully condensed, multi-component working fluid stream in the first stage of the heat exchange unit,

passing the flue gas stream through a large particle separator of a particulate separation and heat transfer subsystem to form a dust laden flue gas stream,

pressurizing the dust laden flue gas stream to form a higher pressure, dust laden flue gas stream,

filtering the higher pressure, dust laden flue gas stream to form a substantially dust free, higher pressure, flue gas stream, and

transferring heat from the substantially dust free, higher pressure, flue gas stream to a second high temperature heat transfer fluid stream in a scrubber to form the cooled flue gas stream and a heated second high temperature heat transfer fluid stream, which is used to fully vaporize and superheat the partially vaporized, multi-component working fluid stream in the second stage of the heat exchange unit.

21. The method of claim 20, further comprising:

pressurizing the heated first high temperature heat transfer fluid stream to form a higher pressure, heated first high temperature heat transfer fluid stream, before being forwarded to the first stage of the heat exchange unit, and

pressurizing the heated second high temperature heat transfer fluid stream to form a higher pressure, heated first high temperature heat transfer fluid stream, before being forwarded to the second stage of the heat exchange unit.