Gas turbine

A gas turbine, comprising:

• a compressor configured to produce compressed air;
• a combustor configured to combust a mixture of fuel and the compressed air to produce heated combustion gas;
• a turbine having a rotor configured to be driven by the heated combustion gas;
• a power generator coupled to the rotor to be driven by the rotor;
• an exhaust diffuser configured to exhaust the combustion gas from the turbine, the exhaust diffuser comprising an inner portion and an outer portion defining therebetween an exhaust passage through which the exhausted combustion gas flows;
• an exhaust-side bearing portion rotatably supporting the rotor at an exhaust side of the turbine;
• a partition wall that connects an end portion of the exhaust-side bearing portion and the inner portion of the exhaust diffuser;
• a space bordered by the exhaust-side bearing portion, the partition wall and the inner portion of the exhaust diffuser;
• an air supply pipe coupled between the compressor and an interior of the exhaust-side bearing portion for supplying cooling air from the compressor to cool the interior of the exhaust-side bearing portion;
• an air discharge pipe communicating the interior of the exhaust-side bearing portion with the space for discharging the cooling air, after cooling the exhaust-side bearing portion, into the space where the discharged cooling air is heated by the exhausted combustion gas in the exhaust passage;
• and
• at least one exhaust hole which is formed through the partition wall and through which the heated discharged cooling air is sucked unobstructedly out of the space into the exhaust passage by the flow of the exhausted combustion gas in the exhaust passage,
• whereby the heated discharged cooling air is exhausted through the exhaust diffuser to prevent carbonization of a lubricant used in the exhaust-side bearing portion.