Dust output control method and control system

Abstract

The invention discloses a dust output control method and a control system for timely treatment of collected dust with low pipeline wear and low consumption of compressed air. The method comprises the following steps: calculating relevant parameters in the dust output process; calculating the dust collecting volume of a dust hopper by means of the calculated relevant parameters; controlling the delivery process of a bin pump or a bin pump group according to the dust collecting volume in the dust hopper; and controlling the delivery time sequence of different bin pumps or bin pump groups according to the calculated dust collecting volume in the dust hopper and relevant time parameters in the delivery process. By adopting the technical scheme, the dust output method has the advantages that the stay time of the dust in the dust hopper is short, the temperature reduction range is small, the hardening and arching are avoided, the system is ensured to be in the concentrated phase delivery state, the delivery efficiency is high, the power consumption is low, and the wear to a blanking valve of the bin pump and a dust output pipeline is minimum.

Description

technical field [0001] The invention relates to the technical field of thermal power generation, in particular to an ash conveying control method and control system. Background technique [0002] At present, the ash conveying system of the thermal power plant unit adopts the dust removal system to collect the fly ash, which is transported to the corresponding ash storage by the warehouse pump after being fluidized by compressed air. [0003] At present, the technological process of fly ash transportation is as follows: open the feed valve of the bin pump, the fly ash enters the bin pump, close the feed valve, feed compressed air to fluidize the fly ash, open the discharge valve to transport the fly ash to the ash After the delivery is completed, close the discharge valve and the compressed air supply valve to complete a delivery process. This cycle goes on and on to complete the transportation of the fly ash produced after the coal combustion of the boiler. [0004] Corres...

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Problems solved by technology

[0007] The above-mentioned ash conveying control methods all have their own deficiencies. Using the full material level signal to trigger the conveying control method has the following disadvantages: the material level switch used to detect the material level of the warehouse pump is prone to failure. The problem of excessive ash volume in the warehouse pump and blockage of the conveying pipeline

[0008] The timing ash delivery control method has the following disadvantages: when the unit load is low and the ash flow rate is small, the timing ash delivery control method will cause a small ash-gas ratio, serious waste of compressed air, serious wear of the ash pipeline and valves; and when the unit load If the operator does not adjust the ash conveying interval in time, it may cause hardening or arching due to a large amount of ash accumulation in the ash hopper, or blockage of the conveying pipeline.

[0009] The intelligent control method of ash conveying pressure waveform has the following disadvantages: Since the pressure waveform is the embodiment of the accumulation of ash in the ash hopper during the conveying process, the judgment of the ash amount in the conveying process lags behind, so it cannot respond in time to the conveyance caused by the change of coal quality. Condition deterioration

When there is a change in unit load, the gray-gas ratio cannot be adjusted in time, resulting in waste of compressed air and wear and tear of the pipeline

[0010] In addition, the above-mentioned various traditional ash conveying control methods cannot coordinate the ash conveying of a single unit with different warehouse pumps, nor can it coordinate the ash conveying of two or more units, and often there are multiple warehouse pumps. Simultaneous ash conveying phenomenon makes the peak flow rate of the compressed air main pipe very high, and the pressure recovery process of the compressed air main pipe takes a long time after the ash conveying is completed, which reduces the output of the ash conveying system

Moreover, due to the high peak flow rate of the compressed air main pipe, the number of operating air compressors increases, and the number of loading and unloading of air compressors increases, resulting in increased energy consumption, maintenance costs and reduced service life of the air compressors.

[0011] However, there is no continuous measurement instrument for ash hopper ash accumulation that meets the requirements for measurement accuracy and reliability. Generally, ash hoppers are only equipped with high and low level switches, which cannot meet the real-time ash accumulation measurement requirements in the ash hopper.

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