Fuel gas and fire coal power generating set dual-coupling power generation method and system

Abstract

The invention discloses a fuel gas and fire coal power generating set dual-coupling power generation method and system. The dual-coupling power generation method includes fuel gas-steam coupling and fuel gas-fire coal coupling; according to fuel gas-steam coupling, due to exhausting of a high pressure cylinder of a turbine and / or gas extracting of the high pressure cylinder, high temperature fuelgas generated by a gasification reactor is cooled, and fuel gas after being subjected to temperature lowering and steam after being subjected to temperature rising are obtained; according to fuel gas-fire coal coupling, the fuel gas after being subjected to temperature lowering is arranged in a combustion area of a pulverized coal boiler and / or a fuel gas combustor in a reduction area to be fed into a hearth to perform coupling power generation; and the dual-coupling power generation system comprises a fuel gas conveying unit, a fuel gas-steam coupling unit and a fuel gas-fire coal coupling unit. According to the fuel gas and fire coal power generating set dual-coupling power generation method and system, the high temperature fuel gas is cooled by means of exhausting and / or gas extractingof the coal-fired unit turbine, complexity of the system is avoided, and the heat exchanging efficiency is also improved while the system reliability is improved; and besides, by optimizing the fuel gas inputting position, the lower load stable combustion capacity of a boiler unit is improved and / or the high load NOx emission level is lowered.

Description

technical field [0001] The invention relates to the technical field of gasification and coal-fired coupled power generation, and more specifically, to a method and system for double-coupled power generation of gas and coal-fired generating sets. Background technique [0002] Biomass energy is a kind of renewable energy. my country is very rich in biomass resources (the planting area of ​​crops in my country exceeds 1 million square kilometers); at the same time, my country is a country with a large population, and a large amount of garbage and sludge are produced every day. Therefore, it is an efficient resource utilization method to couple raw materials such as biomass, garbage, and sludge with coal-fired power generation after gasification. High-temperature combustible synthesis gas (referred to as gas) has a temperature of about 650-900°C. After cooling, the temperature is reduced to 300-550°C and then sent to the boiler for combustion to generate electricity. [0003] T...

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Problems solved by technology

However, the existing gasification and coal-fired coupling technology does not make full use of the advantages of coal-fired units. Some schemes propose multiple coupling methods for biomass gasification and coal-fired units, but ignore the strong reduction of biomass gas itself. It can reduce the NOx emission of coal-fired boilers; some plans point out that the reduction of gas can reduce the NOx emission of boilers, but they do not specify the specific position and operation mode of gas feeding into the boiler furnace; some point out that high temperature The gas can be cooled by heat transfer oil, but the heat transfer oil cannot be coupled with the steam turbine, and can only be used as an intermediate heat exchange medium, etc.

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