Carbonaceous feedstock gasification power generation facility, and method for regulating drying gas carbonaceous feedstock

A carbonaceous feedstock gasification power generation facility, comprising:

• a pulverizing device that pulverizes a carbonaceous feedstock to produce a pulverized fuel;
• a gasifier that gasifies the pulverized fuel to generate a raw syngas;
• a gas turbine that is driven by a combustion gas obtained by combusting the raw syngas;
• a generator that is connected to the gas turbine and driven by the gas turbine;
• a heat recovery steam generator that introduces an exhaust gas being discharged from the gas turbine, is provided with an upstream-side heat exchange portion made up of one or more heat exchangers, an in-furnace denitration device which is a denitration device provided in the gasifier, and a downstream-side heat exchange portion made up of one or more heat exchangers in a furnace in this order from an exhaust gas upstream side, and generates a steam by recovering heat from the exhaust gas in the upstream-side heat exchange portion and the downstream-side heat exchange portion;
• a high-temperature exhaust gas line that bleeds a high-temperature exhaust gas from the furnace at a high-temperature bleed position which is set on an exhaust gas downstream side of the in-furnace denitration device and supplies the high-temperature exhaust gas to the pulverizing device as a drying gas the carbonaceous feedstock, the high-temperature exhaust gas which is bled from a bleed position which is set on the downstream side of the upstream-side heat exchange portion and the in-furnace denitration device and the upstream side of the downstream-side heat exchange portion;
• a low-temperature exhaust gas line that bleeds a low-temperature exhaust gas from the furnace at a low-temperature bleed position which is set on the exhaust gas downstream side of the high-temperature bleed position and set so as to sandwich at least a part of the downstream-side heat exchange portion between the high-temperature bleed position and the low-temperature bleed position and supplies the low-temperature exhaust gas to the high-temperature exhaust gas line or directly to the pulverizing device, the low-temperature exhaust gas is bled from a bleed position which is set on the downstream side of the downstream-side heat exchange portion;
• an extreme high-temperature exhaust gas line that bleeds an extreme high-temperature exhaust gas from the furnace at an extreme high-temperature bleed position which is set on an exhaust gas upstream side of the high-temperature bleed position between an exhaust gas outlet of the gas turbine and the in-furnace denitration device which is a denitration device provided in the gasifier and set so as to sandwich at least a part of the upstream-side heat exchange portion between the high-temperature bleed position and the extreme high-temperature bleed position and supplies the extreme high-temperature exhaust gas to at least one exhaust gas line of the high-temperature exhaust gas line and the low-temperature exhaust gas line, the extreme high-temperature exhaust gas is bled from a bleed position which is set on the upstream side of the upstream-side heat exchange portion;
• and
• temperature adjustment damper that is interposed in the extreme high-temperature exhaust gas line and adjusts a flow rate of the extreme high-temperature exhaust gas being supplied to the at least one exhaust gas line so that a gas temperature in the at least one exhaust gas line reaches a prescribed temperature.