Power boiler low NOx combustion method and control system based on wind powder closed-loop control

Abstract

The present invention discloses a power station boiler low NOx combustion method based on wind powder closed loop control and a boiler primary air wind powder closed loop control system. The method is as follows: the main burner region excessive air coefficient is controlled below 1.0; the deficient air at the upper side of a hearth is supplemented by an SOFA nozzle at AA interval; a function f(Q)=f(N,D) is used to compare NOx actual measured value with target value, wherein N is coal type, D is load and Q is graded air amount; after adjusted by PID, the deviation of the comparison is used as a correcting factor to be overlapped with the coal type-load-graded air amount function f(Q) for adjusting the mixture ratio between the SOFA air amount and the secondary air amount of the combustion region. The system comprises a first signal measuring part, a signal acquiring part, a data processing part and a feedback part. With the closed loop control system, the method ensures, in different working conditions, the even distribution of the first air wind powder of each layer and perfect mixture ratio between the SOFA air amount and the secondary air amount of the combustion region, so that the method realizes the optimized control target of reducing the discharging of boiler contamination NOx and improving boiler efficiency.

Description

technical field [0001] The present invention relates to a power plant boiler low NOx combustion method and control system based on air powder closed-loop control, and more specifically relates to a method for using PM (Pollution Minimum) main burner and MACT (Mitsubishi Advanced Combustion Technology) type low NOx combustion method. Low NOx combustion method based on air powder closed-loop control for boilers with single furnace and ∏-shaped arrangement of tangential combustion in the staged air combustion system and related boiler primary air air powder closed-loop control system. Background technique [0002] my country's primary energy is dominated by coal, and the installed capacity of coal-fired power generation accounts for about 70% of the total installed capacity. NOx emissions from coal-fired power stations were 2.65 million tons in 1995, 4.69 million tons in 2000, and 5.2 million tons in 2005. It is expected to reach 5.5 million tons by 2010. According to the cur...

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Problems solved by technology

In the past, my country's NOx emission standard for coal-fired power plants was relatively loose, which was 650mg / m 3 , and it is not enforced, so the NOx emission concentration of existing coal-fired power plants is relatively high, generally at 700mg / m 3 Some power plants are equipped with OFA low NOx burners, but the NOx emission concentration is still 600mg / m 3 There is still a big gap compared with the advanced level of foreign countries

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