Method of fluidizing wind at high pressure using steam to replace air

Abstract

The invention relates to a method of implementing high pressure fluidization blast using steam in place of air, characterized in that: steam is used for high pressure fluidization blast in normal running of a boiler. The method includes: connecting a turbine exhaust or intermediate extraction with a stock recycler using a steam conduit; starting high pressure fluidization blower and fluidizing recycle material in the stock recycler using air when the boiler begins to start; opening stop valve of the turbine steam conduit, fluidizing recycle material in the stock recycler using steam, shutting down the high pressure fluidization blower and closing the stop valve when the temperature of recycle material in the stock recycler is above 300 Celsius degree, the fluidization steam vapor source pressure parameter is greater than 60Kpa, and the superheat degree is larger than 30 Celsius degree; starting the high pressure fluidization blower, fluidizing recycle material in the stock recycler using air, and closing the stop valve on steam turbine when the temperature of the stock recycler is under 300 Celsius degree in blow off process of the boiler. Advantages of the invention consist in that coking of the stock recycler or other high temperature zones can be prevented or abated and boiler operation reliability can be improved by using steam for replacing high pressure fluidization blast. At the same time, circulating fluid bed boiler desulfurizer utilization rate can be improved, Nox discharge concentration can be reduced, and power plant running cost can be saved by utilizing steam fluidization.

Description

technical field [0001] The invention relates to a method for using steam instead of air to carry out high-pressure fluidization air, which is used for fluidization of a circulating fluidized bed boiler feeder, and belongs to the technical field of circulating fluidized bed boiler fluidization. Background technique [0002] Since the 1980s, circulating fluidized bed boilers have developed rapidly in my country. So far, hundreds of circulating fluidized bed boilers above 130t / h are in operation or are being installed and designed. With the maturity of the combustion technology of circulating fluidized bed boilers, the capacity level of boilers is also increasing. The 135MW circulating fluidized bed boiler with intermediate reheating was also put into commercial operation at the end of 2002. 200MW, 300MW and above circulating fluidized bed The research and development of boilers has also entered the agenda of major scientific research institutes and boiler manufacturers. Practi...

AI Technical Summary

Problems solved by technology

In particular, most circulating fluidized bed boilers currently use high-temperature adiabatic cyclone separators. During operation, it is found that the ash return temperature of the feeder is higher than that of the furnace outlet, and some are 50-100°C higher, resulting in burnt air of the feeder. loss and coking

In addition, due to the high pressure head of the return material fluidization, the power consumption of the fan is high, the noise of the high-pressure head fluidization fan is large, and the vibration of the air duct is serious. Some power plants even found that the air chamber of the return feeder and the The entire feeder was damaged by vibration, which affected the operation of the boiler

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