Primary air and powder amount control system and method suitable for peak regulation

Abstract

Disclosed are a primary air and powder amount control system and method suitable for peak regulation. An air and powder mixture firstly enters a total air and powder box and then enters primary air and powder pipelines, the powder amount is measured through a powder amount measuring device, then the powder amount deviation is obtained, and the powder amount is leveled through a powder amount regulator; the air volume is measured through an air volume measuring device, then the air volume deviation is obtained, the air volume is leveled through an air volume regulator, and therefore double leveling of the air volume and the powder amount is achieved; and for a unit with a relatively low load under a peak regulation state, unstable combustion caused by too low coal powder concentration of part of coal powder pipes and incomplete combustion caused by too high coal powder concentration of part of coal powder pipes can be effectively prevented, safe, economical and flexible operation of a boiler is guaranteed, and the problems that the air volume of a traditional coal powder feeding system cannot be adjusted on line, and the coal powder amount is difficult to adjust are solved.

Description

technical field [0001] The invention belongs to the field of thermal power generation, and in particular relates to a primary air powder volume control system and method suitable for peak regulation. Background technique [0002] The operating state of the boiler combustion system determines the aerodynamic field in the furnace, which is critical to the stability of steam parameters, the safety of the heating surface and combustion equipment. If there is partial burning in the furnace, the flame brushes the wall, the flame center is too high or too low, etc., the boiler is prone to a series of problems such as steam parameters not reaching the design value, overheating of the heating surface, slagging, high-temperature corrosion, etc., which not only reduces the boiler Efficiency also threatens the safe operation of the unit. In order to obtain a good aerodynamic field in the furnace, in addition to the good condition of the combustion equipment, the control of the air volu...

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Problems solved by technology

However, the current powder feeding systems of thermal power units all have deficiencies. For example, the pulverized coal pipelines use fixed or adjustable shrinkage holes to adjust the air volume. Manual adjustment is not only a heavy workload, it is difficult to adjust online in real time, and the shrinkage holes are prone to powder accumulation and spontaneous combustion.

For the adjustment of the powder amount, if the pulverized coal distributor is not installed, it completely depends on the performance of the coal mill separator; even if the powder amount distributor is installed, it is often installed in the primary air powder pipeline at the outlet of the coal mill and the inlet of the burner In the middle, if the powder distribution of each pipeline at the outlet of the coal mill is uneven, subsequent adjustments will also be meaningless

Therefore, the current powder feeding system of thermal power units cannot realize the uniform distribution of air volume and powder volume, resulting in the aerodynamic field difference in the boiler furnace becoming a long-standing problem that cannot be cured

Especially the current thermal power units frequently participate in peak-shaving operation. Due to the small amount of air powder under low load, the number of coal mills and burner layers is small. If a certain layer or several layers, especially the stable combustion layer The large deviation of each air powder pipe in the powder feeding system of the device will easily cause unstable combustion and even cause fire extinguishing of the boiler, which is not conducive to the flexible operation of the unit

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