Method of operating gas turbine power plant with intercooler

• US 5,758,485 A
• Filed: 07/30/1996
• Issued: 06/02/1998
• Est. Priority Date: 08/28/1995
• Status: Expired due to Fees

• Current Assignee: Alstom SA
• Original Assignee: Asea Brown Boveri AG (ABB Limited)
• Inventors: Frutschi, Hans Ulrich
• Primary Examiner(s): Casaregola, Louis J.
• Application Number:
  US08/689,110
• Time in Patent Office: 672 Days
• Field of Search: 60/39.02, 60/39.29, 60/728, 415/179
• US Class Current: 60/772
• CPC Class Codes: F01D 25/007 Preventing corrosion
• CPC Class Codes: F02C 7/143 before or between the compressor stages
• CPC Class Codes: F02C 7/30 Preventing corrosion or unwanted deposits in gas-swept spaces
• CPC Class Codes: Y02E 20/16 Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]

Abstract

In a method of operating a combined-cycle plant which is based on a gas-turbine group, the compressor unit of this same gas-turbine group is equipped with an intercooler (9). By detecting parameters which comprise at least the ambient temperature (T), the air humidity (φ) of intake air (7) and the outlet pressure (Pic) of the intercooler (9), and by feeding the same to a computer (15), regulation is initiated by the latter, which regulation acts on members (17, 18) in the coolant circuit (13, 13a) between the intercooler (9) and a heat sink (14). The dew-point temperature of the cooled air (10), compressed to an intermediate pressure, downstream of the intercooler (9) is thereby influenced.

Claims

1. A method of a operating a power station plant having a low pressure compressor and a high pressure compressor and an intercooler connected in between for cooling air compressed in the low pressure compressor, the intercooler having a coolant circuit through which heated coolant flows to a heat sink and cooled coolant is returned to the intercooler, the plant also having at least one combustion chamber, at least one turbine and at least one generator, the method comprising the steps of:

monitoring values of at least ambient temperature, air humidity of intake air to the low pressure compressor, and outlet air pressure of the intercooler,

determining from the monitored values a dew point temperature for the outlet air of the intercooler,

directing a flow of heated coolant through a bypass upstream of the heat sink to mix into a flow of cooled coolant downstream of the heat sink; and

controlling a flow of cooled coolant from the heat sink to the intercooler,

wherein, a temperature of mixed coolant entering the intercooler is sufficiently high so that the outlet air of the intercooler is not cooled below the dew point.

2. The method as claimed in claim 1, further comprising the step of controlling an intake air flow into the low pressure compressor by adjusting an inlet guide vane row of the low pressure compressor.