Advanced humid air gas turbine system
One of the objects of the invention is to provide a water-saving type advanced humid air gas turbine system (AHAT) that can decrease the amount of makeup water to be supplied from the outside, by reducing the amount of water consumed when the gas turbine system is starting up, shut down, or subjected to load rejection. The gas turbine system includes a compressor, the compressed air header for generating humidified combustion air, a combustor for generating combustion gas, and the turbine. When the gas turbine system is starting up, shut down or subjected to load rejection, steam coming from the heat recovery steam generator is recovered by blocking the first steam system and making the second steam system communicate with the heat recovery steam generator.
1. An advanced humid air gas turbine system comprising:
a gas turbine that includes a compressor for compressing air, a compressed air header for mixing high-pressure air introduced from the compressor with steam to generate humidified combustion air, a combustor for mixing combustion air from the compressed air header with fuel for sake of combustion so as to generate combustion gas, and a turbine driven by the combustion gas that is generated by the combustor;
a heat recovery steam generator for generating steam by use of exhaust gas from the turbine;
a water recovery system disposed on a downstream side of the heat recovery steam generator, the water recovery system condensing moisture in the exhaust gas into water by use of cooling water and recovering moisture contained in the exhaust gas;
a first steam pipe connecting the heat recovery steam generator to the compressed air header and supplying steam, coming from the heat recovery steam generator, to the compressed air header;
a second steam pipe for supplying steam, coming from the heat recovery steam generator, to the water recovery system; and
a steam nozzle installed inside the water recovery system and jetting a superheated steam into the water recovery system;
wherein the second steam pipe is directly connected to said steam nozzle;
wherein the steam nozzle is arranged so as not to come into direct contact with a casing of the water recovery system; and
wherein when the gas turbine is starting up, shut down, or subjected to load rejection, steam coming from the heat recovery steam generator is recovered by blocking the first steam pipe and making the second steam pipe communicate with the heat recovery steam generator.