CONTROL UNIT FOR GASIFICATION POWER GENERATION PLANT, GASIFICATION POWER GENERATION PLANT, AND CONTROL METHOD FOR GASIFICATION POWER GENERATION PLANT

摘要

An IGCC plant includes a coal gasifier that gasifies coal by using an oxidizer, a gas turbine that is driven by combustion gas generated by combustion of fuel gas obtained by purifying gas generated by the coal gasifier in gas clean-up equipment, and an oxidizer supply path for supplying air extracted from an air compressor of the gas turbine or oxygen separated from the air as an oxidizer for the coal gasifier. A control unit (50) for the gasification power generation plant controls the amount of the oxidizer that is supplied to the coal gasifier to be less than or equal to a predetermined upper-limit value, while allowing deviation of an air ratio from a predetermined set value, the air ratio representing the ratio of the amount of air that is supplied to the coal gasifier relative to a theoretical amount of air for combustion of carbon, in accordance with variations in an operating-state quantity of the coal gasifier or variations in a load of the IGCC plant. Accordingly, the capacity of the oxidizer supplying equipment need not be increased in the IGCC plant, and it is possible to quickly stabilize control of the plant as a whole.

主权项

1. A control unit for a gasification power generation plant including a gasifier that gasifies carbon-containing fuel by using an oxidizer, a gas turbine that is driven by combustion gas generated by combustion of fuel gas obtained by purifying synthesis gas from the gasifier in gas clean-up equipment, and an oxidizer supply path for supplying air extracted from an air compressor of the gas turbine or oxygen separated from the air as an oxidizer for the gasifier,
the control unit for the gasification power generation plant comprising a switching unit for choosing a fixed-air-ratio mode, in which an air ratio representing the ratio of the amount of the oxidizer that is supplied to the gasifier relative to a theoretical amount of the oxidizer for combustion of the carbon-containing fuel is fixed, in a case where the gasification power generation plant is in a stable state, whereas choosing a variable-air-ratio mode, in which the air ratio is variable, in a case where an operating-state quantity of the gasifier has varied or in a case where a load of the gasification power generation plant has varied.