Method for starting up a combination gas and steam power plant

• US 5,682,737 A
• Filed: 06/20/1996
• Issued: 11/04/1997
• Est. Priority Date: 08/08/1995
• Status: Expired due to Term

• Current Assignee: Alstom Technology Ltd. (Alstom SA)
• Original Assignee: Asea Brown Boveri AG (ABB Limited)
• Inventors: Schmidli, Jurg
• Primary Examiner(s): Casaregola, Louis J.
• Application Number:
  US08/667,871
• Time in Patent Office: 502 Days
• Field of Search: 60/39.02, 60/39.141, 60/39.142, 60/39.181, 60/39.182, 60/39.463, 60/39.465
• US Class Current: 60/778
• CPC Class Codes: F01K 23/16 all the engines being turbines F01K23/14 takes precedence
• CPC Class Codes: Y02E 20/16 Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]

Abstract

In a method for starting up a combination plant designed as a single-shaft plant with a common shafting (10) and essentially consisting of a compressor (1), a combustion chamber (2), a turbine (3), a steam turbine (5), a generator (6) and a fuel compressor (4) for compressing low-calorie fuels (12), the steam turbine (5) is started up by means of extraneous steam (33) introduced into the steam turbine. The gas turbine (1, 2, 3) is started up by means of the steam turbine (5), medium-calorie or high-calorie auxiliary fuel (21) is ignited in the combustion chamber (2) and the shafting (10) is run at nominal speed. The power required for compressing the low-calorie fuel (12) in the fuel compressor (4) is applied by means of the auxiliary fuel (21) and the extraneous steam (33) and, when there is sufficient pressure in the fuel compressor (4), a changeover is made from the auxiliary fuel (21) to the low-calorie fuel (12).

Claims

1. A method for starting up a combination plant designed as a single-shaft plant with common shafting (10) and essentially consisting of a compressor (1), a combustion chamber (2), a turbine (3), a steam turbine (5), a generator (6) and a fuel compressor (4) for compressing low-calorie fuels (12), wherein the steam turbine (5) is started up by means of extraneous steam (33) introduced into the steam turbine, wherein the gas turbine (1, 2, 3) is started up by means of the steam turbine (5), wherein medium-calorie or high-calorie auxiliary fuel (21) is ignited in the combustion chamber (2), wherein the shafting (10) is run at nominal speed, wherein .the power required for compressing the low-calorie fuel (12) in the fuel compressor (4) is applied by means of the auxiliary fuel (21) and the extraneous steam (33), and wherein, when there is sufficient pressure in the fuel compressor (4), a changeover is made from the auxiliary fuel (21) to the low-calorie fuel (12).

2. The startup method as claimed in claim 1, wherein the exhaust gases of the turbine (3) are used for the production steam in a waste heat boiler (30), wherein the steam (31) occurring is introduced, in addition to the extraneous steam (33), into the steam turbine (5), and wherein the power required for compressing the low-calorie fuel (12) in the fuel compressor (4) is applied by means of the auxiliary fuel (21), the extraneous steam (33) and the steam generated in the waste heat boiler (30).

3. The startup method as claimed in claim 1, wherein at most sufficient auxiliary fuel (21) is burnt in the combustion chamber (2) to ensure that the heat load there becomes no higher than with low-calorie fuel (12) under full load.