Power generation plant

Abstract

A power-generation plant 10 including a gas turbine 11; a fuel-gas cooler 13; and an extraction line 24 that guides the fuel gas extracted from an intermediate stage of a fuel-gas compressor 12 to the fuel-gas cooler 13; a first level detector 61 that detects whether a level of the coolant accumulated at a bottom portion of the fuel-gas cooler 13 has reached a predetermined level; and a controller that stops the gas turbine 11 on the basis of a detection signal sent from the first level detector 61 and that outputs a command signal for stopping a coolant pump 53 that supplies the coolant to the spray nozzles 44 and 45.

What is claimed is: 
     
         1 . A power-generation plant comprising:
 a gas turbine that combusts fuel gas;   a fuel-gas cooler that cools the fuel gas, which is pressurized at a fuel-gas compressor and recirculated, with coolant sprayed from a spray nozzle;   a bypass line that guides the fuel gas, which is pressurized at the fuel-gas compressor and recirculated, to the fuel-gas cooler;   a level detector that detects whether a level of the coolant accumulated in the bypass line has reached a predetermined level; and   a controller that stops the gas turbine on the basis of a detection signal sent from the level detector and that outputs a command signal for stopping a coolant pump that supplies the coolant to the spray nozzle.   
     
     
         2 . A power-generation plant comprising:
 a gas turbine that combusts fuel gas;   a fuel-gas cooler that cools the fuel gas, which is pressurized at a fuel-gas compressor and recirculated, with coolant sprayed from a spray nozzle; and   a coolant pipe that supplies the coolant to the spray nozzle,   wherein the coolant pipe is provided with a bypass pipe that returns the coolant to the interior of the fuel-gas cooler by bypassing the spray nozzle.   
     
     
         3 . A power-generation plant according to  claim 2 , wherein a pipe leading to the spray nozzle is provided with a pressure detector for detecting the pressure of the coolant that passes through the pipe. 
     
     
         4 . A method of stopping a power-generation plant including
 a gas turbine that combusts fuel gas;   a fuel-gas cooler that cools the fuel gas, which is pressurized at a fuel-gas compressor and recirculated, with coolant sprayed from a spray nozzle; and   a bypass line that guides the fuel gas, which is pressurized at the fuel-gas compressor and recirculated, to the fuel-gas cooler,   the method comprising:   stopping the gas turbine when a level of the coolant accumulated in the bypass line has reached a predetermined level; and   stopping a coolant pump that supplies the coolant to the spray nozzle.