Combined cycle power plant

• US 20010023580A1
• Filed: 05/30/2001
• Published: 09/27/2001
• Est. Priority Date: 04/07/1998
• Status: Active Grant

• Current Assignee: mitsubishi hitachi power systems, ltd. (Mitsubishi Heavy Industries, Ltd.)
• Original Assignee: Hideaki Sugishita, Hidetaka Mori, Ichiro Fukue, Kazuo Uematsu
• Inventors: Uematsu, Kazuo, Sugishita, Hideaki, Mori, Hidetaka, Fukue, Ichiro
• Granted Patent: US 6,430,916 B2
• Time in Patent Office: Days
• US Class Current: 60/39.12
• CPC Class Codes: C01B 2203/0205 containing a reforming step
• CPC Class Codes: C01B 2203/0811 by combustion of fuel
• CPC Class Codes: C01B 2203/1223 Methanol
• CPC Class Codes: C01B 3/32 by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
• CPC Class Codes: F01K 23/10 with exhaust fluid of one cycle heating the fluid in another cycle F01K17/025 takes precedence
• CPC Class Codes: Y02E 20/16 Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]
• CPC Class Codes: Y02E 20/34 Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery

Abstract

Provided is turbine plant using methanol as fuel in which working fluid is compressed by compressor 1 and led into combustor 2. A mixture of H₂ and CO₂ as fuel added with O₂ is burned to generate high temperature gas, which works at high temperature turbine 3, flows through heat exchangers 4, 5 and returns partly to the compressor 1 and enters partly low pressure turbine 7 of bottoming system to work. Condensed water from condenser 9 of the bottoming system is pressurized by pressure pump 10 and flows through the heat exchangers 4, 5 to become high temperature steam and to work at high pressure turbine 6. Exhaust gas thereof is mixed into the combustor 2. A mixture of methanol and water is supplied into reformer 13 to absorb heat from the heat exchanger 4 to be reformed into H₂ and CO₂, which is supplied into the combustor 2. A high temperature portion of the high temperature turbine 3 is cooled by cooling medium extracted from compressor 1 outlet and high pressure turbine 6 outlet thereby reliability of the high temperature turbine 3 is enhanced.

Claims

1. A power plant comprising:

a compressor for compressing a mixture gas of steam and carbon dioxide so as to produce a working fluid;

a combustor disposed downstream of said compressor and adapted to receive and burn oxygen, a reformed fuel mixture of hydrogen and carbon dioxide, and the working fluid produced by said compressor so as to produce a combustion gas;

a gas turbine disposed downstream of said combustor and adapted to receive and expand the combustion gas produced by said combustor so as to produce an exhaust gas;

a bottoming system disposed downstream of said gas turbine and including a condenser for receiving and condensing the exhaust gas from said gas turbine so as to produce water;

a heat exchanger having an exhaust gas side disposed downstream of said gas turbine for receiving and cooling the exhaust gas produced by said gas turbine so as to produce the mixture gas to be compressed by said compressor, and having a water side disposed downstream of said bottoming system for heating the water condensed by said bottoming system by using the exhaust gas in said exhaust gas side so as to produce steam;

a steam turbine disposed downstream of said water side of said heat exchanger for receiving and expanding the steam produced by said water side of said heat exchanger so as to produce exhaust steam, said steam turbine being disposed upstream of said combustor such that said combustor receives the exhaust steam produced by said steam turbine;

a reformer having an exhaust gas side for receiving the exhaust gas from said gas turbine and a fuel side for receiving a fuel mixture of methanol and water, said reformer being adapted so that the fuel mixture of methanol and water in said fuel side is heated by using the exhaust gas in said exhaust gas side so as to produce the reformed fuel mixture of hydrogen and carbon dioxide, said fuel side of said reformer being disposed upstream of said combustor such that said combustor receives the reformed fuel mixture of hydrogen and carbon dioxide produced by said reformer;

a gas turbine cooling system for extracting a portion of the working fluid produced by said compressor and a portion of the exhaust steam produced by said steam turbine so as to produce a cooling medium, and for channeling the cooling medium into said gas turbine so as to cool said gas turbine; and

a regenerative heat exchanger having a working fluid side between said compressor and said combustor for receiving the working fluid from said compressor, and having an exhaust gas side between said gas turbine and said heat exchanger for receiving the exhaust gas from said gas turbine, said regenerative heat exchanger being adapted to heat the working fluid by using the exhaust gas in the exhaust gas side;

wherein said bottoming system includes no low pressure turbine and includes no CO₂ compressor, said bottoming system and said compressor being arranged such that a portion of the water produced by said bottoming system is supplied to said compressor, said heat exchanger and said bottoming system being arranged such that the exhaust gas cooled by said heat exchanger is received by said bottoming system.

2. The power plant of

claim 1

, wherein said compressor comprises a low pressure compressor, a high pressure compressor, and a passage connecting said low pressure compressor and said high pressure compressor, said compressor further comprising an intercooler in said passage, said bottoming system and said intercooler being arranged such that a portion of the water produced by said bottoming system is supplied to said intercooler.

3. A power plant comprising:

a compressor for compressing a mixture gas of steam and carbon dioxide so as to produce a working fluid;

a combustor disposed downstream of said compressor and adapted to receive and burn oxygen, a reformed fuel mixture of hydrogen and carbon dioxide, and the working fluid produced by said compressor so as to produce a combustion gas;

a gas turbine disposed downstream of said combustor and adapted to receive and expand the combustion gas produced by said combustor so as to produce an exhaust gas;

a bottoming system disposed downstream of said gas turbine and including a condenser for receiving and condensing the exhaust gas from said gas turbine so as to produce water;

a heat exchanger having an exhaust gas side disposed downstream of said gas turbine for receiving and cooling the exhaust gas produced by said gas turbine so as to produce the mixture gas to be compressed by said compressor, and having a water side disposed downstream of said bottoming system for heating the water condensed by said bottoming system by using the exhaust gas in said exhaust gas side so as to produce steam;

a steam turbine disposed downstream of said water side of said heat exchanger for receiving and expanding the steam produced by said water side of said heat exchanger so as to produce exhaust steam, said steam turbine being disposed upstream of said combustor such that said combustor receives the exhaust steam produced by said steam turbine;

a reformer having an exhaust gas side for receiving the exhaust gas from said gas turbine and a fuel side for receiving a fuel mixture of methanol and water, said reformer being adapted so that the fuel mixture of methanol and water in said fuel side is heated by using the exhaust gas in said exhaust gas side so as to produce the reformed fuel mixture of hydrogen and carbon dioxide, said fuel side of said reformer being disposed upstream of said combustor such that said combustor receives the reformed fuel mixture of hydrogen and carbon dioxide produced by said reformer;

a gas turbine cooling system for extracting a portion of the working fluid produced by said compressor and a portion of the exhaust steam produced by said steam turbine so as to produce a cooling medium, and for channeling the cooling medium into said gas turbine so as to cool said gas turbine; and

a regenerative heat exchanger having a working fluid side between said compressor and said combustor for receiving the working fluid from said compressor, and having an exhaust gas side between said gas turbine and said heat exchanger for receiving the exhaust gas from said gas turbine, said regenerative heat exchanger being adapted to heat the working fluid by using the exhaust gas in the exhaust gas side;

wherein said bottoming system includes a CO₂ compressor and includes no low pressure turbine, said bottoming system and said compressor being arranged such that a portion of the water produced by said bottoming system is supplied to said compressor, said heat exchanger and said bottoming system being arranged such that the exhaust gas cooled by said heat exchanger is received by said bottoming system.

4. The power plant of

claim 3

, wherein said compressor comprises a low pressure compressor, a high pressure compressor, and a passage connecting said low pressure compressor and said high pressure compressor, said compressor further comprising an intercooler in said passage, said bottoming system and said intercooler being arranged such that a portion of the water produced by said bottoming system is supplied to said intercooler.

5. A power plant comprising:

a compressor for compressing a mixture gas of steam and carbon dioxide so as to produce a working fluid;

a combustor disposed downstream of said compressor and adapted to receive and burn oxygen, a reformed fuel mixture of hydrogen and carbon dioxide, and the working fluid produced by said compressor so as to produce a combustion gas;

a gas turbine disposed downstream of said combustor and adapted to receive and expand the combustion gas produced by said combustor so as to produce an exhaust gas;

a bottoming system disposed downstream of said gas turbine and including a condenser for receiving and condensing the exhaust gas from said gas turbine so as to produce water;

a heat exchanger having an exhaust gas side disposed downstream of said gas turbine for receiving and cooling the exhaust gas produced by said gas turbine so as to produce the mixture gas to be compressed by said compressor, and having a water side disposed downstream of said bottoming system for heating the water condensed by said bottoming system by using the exhaust gas in said exhaust gas side so as to produce steam, said heat exchanger being disposed directly upstream of said combustor such that said combustor receives the steam produced by said heat exchanger;

a reformer having an exhaust gas side for receiving the exhaust gas from said gas turbine and a fuel side for receiving a fuel mixture of methanol and water, said reformer being adapted so that the fuel mixture of methanol and water in said fuel side is heated by using the exhaust gas in said exhaust gas side so as to produce the reformed fuel mixture of hydrogen and carbon dioxide, said fuel side of said reformer being disposed upstream of said combustor such that said combustor receives the reformed fuel mixture of hydrogen and carbon dioxide produced by said reformer; and

a gas turbine cooling system for extracting a portion of the working fluid produced by said compressor so as to produce a cooling medium, and for channeling the cooling medium into said gas turbine so as to cool said gas turbine.

6. The power plant of

claim 5

, wherein said gas turbine cooling system is adapted to further extract a portion of the water being heated in said water side of said heat exchanger so as to produce the cooling medium.

7. The power plant of

claim 6

, wherein said compressor comprises a low pressure compressor, a high pressure compressor, and a passage connecting said low pressure compressor and said high pressure compressor, said compressor further comprising an intercooler in said passage, said bottoming system and said intercooler being arranged such that a portion of the water produced by said bottoming system is supplied to said intercooler.

8. The power plant of

claim 6

, wherein said bottoming system includes no low pressure turbine and includes no CO₂ compressor, said bottoming system and said compressor being arranged such that a portion of the water produced by said bottoming system is supplied to said compressor, said heat exchanger and said bottoming system being arranged such that the exhaust gas cooled by said heat exchanger is received by said bottoming system.

9. The power plant of

claim 8

, wherein said compressor comprises a low pressure compressor, a high pressure compressor, and a passage connecting said low pressure compressor and said high pressure compressor, said compressor further comprising an intercooler in said passage, said bottoming system and said intercooler being arranged such that a portion of the water produced by said bottoming system is supplied to said intercooler.

10. The power plant of

claim 6

, wherein said bottoming system includes a CO₂ compressor and includes no low pressure turbine, said bottoming system and said compressor being arranged such that a portion of the water produced by said bottoming system is supplied to said compressor, said heat exchanger and said bottoming system being arranged such that the exhaust gas cooled by said heat exchanger is received by said bottoming system.

11. The power plant of

claim 10

, wherein said compressor comprises a low pressure compressor, a high pressure compressor, and a passage connecting said low pressure compressor and said high pressure compressor, said compressor further comprising an intercooler in said passage, said bottoming system and said intercooler being arranged such that a portion of the water produced by said bottoming system is supplied to said intercooler.

12. The power plant of

claim 5

, wherein said bottoming system includes a low pressure steam turbine upstream of said condenser such that said condenser receives and condenses steam from said low pressure steam turbine so as to produce water, an inlet of said low pressure turbine being disposed downstream of said gas turbine so as to receive the exhaust gas produced by said gas turbine.

13. A turbine plant comprising a compressor for compressing a mixture gas of steam and carbon dioxide as a working fluid;

a combustor for burning a fossil fuel including methanol together with the working fluid from said compressor added with oxygen;

a high temperature turbine for expanding a combustion gas from said combustor to obtain a work;

a bottoming system for driving a low pressure turbine by an exhaust gas from said high temperature turbine to obtain a work;

a heat exchanger for heating a condensed water from said bottoming system to a high temperature steam by a heat exchange with the exhaust gas from said high temperature turbine and for leading said exhaust gas after used for the heat exchange into an inlet of said compressor as the working fluid; and

a high pressure turbine for expanding the high temperature steam of said bottoming system heated at said heat exchanger to obtain a work and for mixing the steam so expanded into said combustor, wherein said compressor comprises a low pressure compressor and a high pressure compressor and is constructed such that there is provided between said low pressure compressor and said high pressure compressor a passage for flowing therethrough the working fluid via an intercooler; and

a portion of the condensed water from said bottoming system is mixed into said intercooler under pressure; and

there is provided a high temperature turbine cooling system for extracting the working fluid from an outlet of said high pressure compressor and an outlet of said high pressure turbine to be led into a high temperature portion of said high temperature turbine for cooling thereof as a cooling medium.

14. A turbine plant comprising a compressor for compressing a mixture gas of steam and carbon dioxide as a working fluid;

a combustor for burning a fossil fuel including methanol together with the working fluid from said compressor added with oxygen;

a high temperature turbine for expanding a combustion gas from said combustor to obtain a work;

a bottoming system for driving a low pressure turbine by an exhaust gas from said high temperature turbine to obtain a work;

a heat exchanger for heating a condensed water from said bottoming system to a high temperature steam by a heat exchange with the exhaust gas from said high temperature turbine and for leading said exhaust gas after used for the heat exchange into an inlet of said compressor as the working fluid; and

a high pressure turbine for expanding the high temperature steam of said bottoming system heated at said heat exchanger to obtain a work and for mixing the steam so expanded into said combustor, wherein there is provided between the outlet of said compressor and an inlet of said combustor a regenerative heat exchanger for elevating a combustor inlet gas temperature by a heat exchange between an outlet gas of said compressor and the exhaust gas from said high temperature turbine; and

there is provided a high temperature turbine cooling system for extracting the working fluid from an outlet of said compressor and an outlet of said high pressure turbine to be led into a high temperature portion of said high temperature turbine for cooling thereof as a cooling medium.

15. A turbine plant as claimed in

claim 14

, wherein said compressor comprises a low pressure compressor and a high pressure compressor;

there is provided between said low pressure compressor and said high pressure compressor a passage for flowing therethrough the working fluid via an intercooler; and

a portion of the condensed water from said bottoming system is mixed into said intercooler under pressure.

20. A turbine plant as claimed in

claim 14

, wherein said bottoming system comprises only a water condensing system having no low pressure turbine and no CO₂ compressor therein and is constructed such that the condensed water from said bottoming system is partly led into the inlet of said compressor as the working fluid;

and the exhaust gas from said high temperature turbine after so heat-exchanged at said heat exchanger is led into a condenser of said bottoming system.

21. A turbine plant as claimed in

claim 20

, wherein said compressor comprises a low pressure compressor and a high pressure compressor;

there is provided between said low pressure compressor and said high pressure compressor a passage for flowing therethrough the working fluid via an intercooler; and

a portion of the condensed water from said bottoming system is mixed into said intercooler under pressure.

24. A turbine plant as claimed in

claim 14

, wherein said bottoming system comprises a water condensing system and a CO₂ compressor having no low pressure turbine therein;

the condensed water from said water condensing system is partly led into the inlet of said compressor as the working fluid; and

the exhaust gas from said high temperature turbine after so heat-exchanged at said heat exchanger is led into said water condensing system.

25. A turbine plant as claimed in

claim 24

, wherein said compressor comprises a low pressure compressor and a high pressure compressor;

there is provided between said low pressure compressor and said high pressure compressor a passage for flowing therethrough the working fluid via an intercooler; and

a portion of the condensed water from said bottoming system is mixed into said intercooler under pressure.

16. A turbine plant comprising a compressor for compressing a mixture gas of steam and carbon dioxide as a working fluid;

a combustor for burning a fossil fuel including methanol together with the working fluid from said compressor added with oxygen;

a high temperature turbine for expanding a combustion gas from said combustor to obtain a work;

a bottoming system for driving a low pressure turbine by an exhaust gas from said high temperature turbine to obtain a work;

a heat exchanger for heating a condensed water from said bottoming system to a high temperature steam by a heat exchange with the exhaust gas from said high temperature turbine and for leading said exhaust gas after used for the heat exchange into an inlet of said compressor as the working fluid; and

a high pressure turbine for expanding the high temperature steam of said bottoming system heated at said heat exchanger to obtain a work and for mixing the steam so expanded into said combustor, wherein a heated steam of bottoming system from said heat exchanger is directly mixed into said combustor via a passage where said high pressure turbine is eliminated; and

there is provided a high temperature turbine cooling system for extracting the working fluid from an outlet of said compressor and a high temperature gas side of said heat exchanger to be led into a high temperature portion of said high temperature turbine for cooling thereof as a cooling medium.

17. A turbine plant as claimed in

claim 16

, wherein said compressor comprises a low pressure compressor and a high pressure compressor;

there is provided between said low pressure compressor and said high pressure compressor a passage for flowing therethrough the working fluid via an intercooler; and

a portion of the condensed water from said bottoming system is mixed into said intercooler under pressure.

18. A turbine plant comprising a compressor for compressing a mixture gas of steam and carbon dioxide as a working fluid;

a combustor for burning a fossil fuel including methanol together with the working fluid from said compressor added with oxygen;

a high temperature turbine for expanding a combustion gas from said combustor to obtain a work;

a bottoming system for driving a low pressure turbine by an exhaust gas from said high temperature turbine to obtain a work;

a heat exchanger for heating a condensed water from said bottoming system to a high temperature steam by a heat exchange with the exhaust gas from said high temperature turbine and for leading said exhaust gas after used for the heat exchange into an inlet of said compressor as the working fluid; and

a high pressure turbine for expanding the high temperature steam of said bottoming system heated at said heat exchanger to obtain a work and for mixing the steam so expanded into said combustor, wherein said bottoming system comprises only a water condensing system having no low pressure turbine and no CO₂ compressor therein and is constructed such that the condensed water from said water condensing system is partly led into the inlet of said compressor as the working fluid;

the condensed water from said water condensing system is partly heat-exchanged with the exhaust gas from said high temperature turbine at said heat exchanger;

the high temperature steam generated by the heat exchange is directly mixed into said combustor via a passage where said high pressure turbine is eliminated; and

the exhaust gas from said high temperature turbine after so heat-exchanged is led into the water condensing system of said bottoming system; and

there is provided a high temperature turbine cooling system for extracting the working fluid from an outlet of said compressor and a high temperature gas side of said heat exchanger to be led into a high temperature portion of said high temperature turbine for cooling thereof as a cooling medium.

19. A turbine plant as claimed in

claim 18

, wherein said compressor comprises a low pressure compressor and a high pressure compressor;

there is provided between said low pressure compressor and said high pressure compressor a passage for flowing therethrough the working fluid via an intercooler; and

a portion of the condensed water from said bottoming system is mixed into said intercooler under pressure.

22. A turbine plant comprising a compressor for compressing a mixture gas of steam and carbon dioxide as a working fluid;

a combustor for burning a fossil fuel including methanol together with the working fluid from said compressor added with oxygen;

a high temperature turbine for expanding a combustion gas from said combustor to obtain a work;

a bottoming system for driving a low pressure turbine by an exhaust gas from said high temperature turbine to obtain a work;

a heat exchanger for heating a condensed water from said bottoming system to a high temperature steam by a heat exchange with the exhaust gas from said high temperature turbine and for leading said exhaust gas after used for the heat exchange into an inlet of said compressor as the working fluid; and

a high pressure turbine for expanding the high temperature steam of said bottoming system heated at said heat exchanger to obtain a work and for mixing the steam so expanded into said combustor, wherein said bottoming system comprises a water condensing system and a CO₂ compressor having no low pressure turbine therein and is constructed such that the condensed water from said water condensing system is partly led into the inlet of said compressor as the working fluid;

the condensed water from said water condensing system is partly heat-exchanged with the exhaust gas from said high temperature turbine at said heat exchanger;

the high temperature steam generated by the heat exchange is directly mixed into said combustor via a passage where said high pressure turbine is eliminated; and

the exhaust gas from said high temperature turbine after so heat-exchanged is led into the water condensing system of said bottoming system; and

there is provided a high temperature turbine cooling system for extracting the working fluid from an outlet of said compressor and a high temperature gas side of said heat exchanger to be led into a high temperature portion of said high temperature turbine for cooling thereof as a cooling medium.

23. A turbine plant as claimed in

claim 22

, wherein said compressor comprises a low pressure compressor and a high pressure compressor;

there is provided between said low pressure compressor and said high pressure compressor a passage for flowing therethrough the working fluid via an intercooler; and

a portion of the condensed water from said bottoming system is mixed into said intercooler under pressure.