Energy-saving start system of IGCC power station

Abstract

An energy-saving start system of an IGCC power station is composed of a coal gasification unit, an air separating unit, a gas turbine, a gas turbine generator, an afterburning fan, an afterburner, a waste heat boiler, a turbine, a turbonator and a flare tower. When the power station is started, the air separating unit and the coal gasification unit are started first, synthesis gas generated by thecoal gasification unit is conveyed to the afterburner to start the waste heat boiler and the turbine power generating system, and until the gas turbine is started and synthesis gas fuel is switched,afterburner stops running; the sequence limit that the waste heat boiler and the turbine must wait for first start of the gas turbine in the conventional start process is eliminated, the turbine can be started before the gas turbine, the start time of the whole plant is shortened, the links of waiting for turbine heating, impulse starting and grid-connection in the loading-up process after gas turbine ignition are omitted, load-up and fuel switching can be conducted on the gas turbine fast, and the energy-saving effect is remarkable.

Description

technical field [0001] The invention relates to the technical field of clean coal-fired power generation, in particular to an energy-saving starting system for an IGCC power station. Background technique [0002] After years of technology accumulation and practice, IGCC (Integrated Gasification Combined Cycle) power generation technology has gradually improved its operation technology and greatly improved its reliability. The available hours of annual power generation are already comparable to those of conventional coal-fired power plants. However, the start-up method of the existing IGCC power station is not perfect enough, the start-up process takes a long time, energy waste and high start-up cost are prominent problems in the start-up process of the IGCC power station. [0003] On the one hand, in order to ensure the reliability of the IGCC power station and increase the flexibility of the overall system, many of the IGCC power stations use independent electric drive air ...

AI Technical Summary

Problems solved by technology

Therefore, if the start-up process of the whole plant is too slow, the power consumption of the air separation system will increase and the cost of power purchase will increase

On the other hand, in the IGCC system, the gas turbine, the waste heat boiler and the steam turbine form a combined cycle system. The waste heat boiler uses the exhaust heat of the gas turbine to generate steam and sends it to the steam turbine for power generation. If you want to start the steam turbine, you must first start the gas turbine. The speed of rushing and grid connection is relatively slow. This process requires the gas turbine to keep waiting at a low load, and the gas turbine needs to be started with light diesel oil. After the gas turbine load rises to about 55% to 70% of the rated load, it can switch to syngas Fuel, the cost of burning light diesel is very high, and in the process of starting the gas turbine with the steam turbine, because the gas turbine is kept at a low load, it must continue to burn light diesel, which lasts for a long time and costs a lot of fuel

In addition, since the gas turbine is started in conjunction with the steam turbine, the low load lasts for a long time, which causes the gas turbine to be unable to switch to syngas fuel for a long time. waste

On the whole, the typical start-up method of the existing IGCC power station has the problems of long start-up time, large power consumption, high fuel consumption, serious energy waste and high start-up cost

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