Method for operating a power plant by means of a CO2process

• US 7,089,743 B2
• Filed: 05/25/2004
• Issued: 08/15/2006
• Est. Priority Date: 02/25/1998
• Status: Expired due to Fees

• Current Assignee: Alstom SA
• Original Assignee: Alstom SA
• Inventors: Frutschi, Hans Ulrich, Wettstein, Hans
• Primary Examiner(s): Rodriguez, William H.
• Application Number:
  US10/852,656
• Publication Number:
  US 20050076645A1
• Time in Patent Office: 812 Days
• Field of Search: 60/390.2, 60/395.2, 60/394.61, 607/72
• US Class Current: 60/772
• CPC Class Codes: F01K 21/042 pure steam being expanded in a motor somewhere in the plant F01K21/045 takes precedence
• CPC Class Codes: F01K 21/047 having at least one combustion gas turbine
• CPC Class Codes: F02C 1/10 Closed cycles
• 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
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

In a method for operating a power plant by means of a CO₂ process, isentropic compression first takes place, subsequently an isobaric heat supply, then isentropic expansion, and finally isobaric heat discharge. The CO₂ process broken down here takes place with internal combustion, a fuel (21) and the oxygen (18) necessary for oxidization being supplied. After the charging of the CO₂ circuit (23) has been carried out, the excess CO₂ formed from combustion is discharged continuously, in that this gas is led through a cooler (14), in which said gas is condensed. In order to dispose of this condensed CO₂ (15), there are available here, for example, the possibilities of storing this CO₂ on the ocean floor or of introducing the condensed CO₂ into a worked-out deposit of natural gas.

Claims

1. A method for operating a power plant including a CO2 process, the method comprising the steps of:

compressing a working fluid into a circulation gas, a first secondary stream and a second secondary stream;

heating the circulation gas at a constant pressure, heating the circulation gas at a constant volume, or both;

expanding the circulation gas at a constant entropy;

discharging heat from the circulation gas at a constant pressure, discharging heat from the circulation gas at a constant volume, or both;

introducing the first secondary stream to an input side of a turbine; and

regulating the degree of charging of the process at the input side of the turbine by controlling discharge of the second secondary stream to extract CO2; and

the CO2 process comprising internal combustion of a fuel and an oxidant necessary for oxidation.

2. The method as claimed in claim 1, further comprising:

condensing excess water and CO2; and

separating the condensed water and CO2 out from the process.

3. The method as claimed in claim 2, further comprising:

condensing out a CO2 part quantity from the process in a cooler.

4. The method as claimed in claim 3, further comprising:

separating out parasitic gases occurring in the process downstream of the cooler.

5. The method as claimed in claim 1, further comprising:

starting up the power plant by the connection of an air startup flap acting upstream of compression.

6. The method as claimed in claim 1, wherein in the compression step and the expansion step, the entropy of the circulation gas remains approximately constant.

7. The method of claim 1, wherein the second secondary stream is branched off from the first secondary stream.

8. The method of claim 1, wherein the regulating step comprises regulating the power of the process by extracting CO2 by means of a regulating means regulating the discharge of the second secondary stream.