Method for operating a gas and steam turbine plant

US5251432A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Hermann Bruckner · Uttenreuth, DE
• Werner Emsperger · Erlangen, DE

Key dates

• Filing date: Jul 17, 1992
• Grant date: Oct 12, 1993
• Expiry date: Jul 17, 2012

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/12
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A gas and steam turbine plant includes a steam turbine having a water-steam loop. A waste heat boiler which is connected downstream of a gas turbine includes a high-pressure preheater connected in the water-steam loop, a high-pressure heater connected downstream of the high-pressure preheater, a low-pressure heater connected upstream of the high-pressure preheater, and an evaporator of a medium-pressure heater. A coal gasification plant is connected upstream of the gas turbine. An outflow line leads into the coal gasification plant and is connected to the water-steam loop downstream of the high-pressure preheater, as seen in water flow direction. A water-steam drum communicates with the outflow line and is connected to the evaporator. A method for operating the plant includes generating steam for the steam turbine with working fluid expanded in the gas turbine. A partial quantity of preheated water at high pressure is drawn from the water-steam loop of the steam turbine and cools coal gas, when coal gas is used as fuel for the gas turbine. The drawn partial quantity is expanded and steam being formed in the process is superheated at medium pressure, both in partial-load operation a…