Pulverized coal tube pulverized coal flow obtaining method in dual-inlet dual-outlet steel ball milling direct blowing type coal pulverizing system

Abstract

The invention discloses a pulverized coal tube pulverized coal flow obtaining method in a dual-inlet dual-outlet steel ball milling direct blowing type coal pulverizing system. The method comprises the steps that the relation or relation curve between the pulverized coal amount in a coal mill large tank and the surface area of the pulverized coal exposed under the primary air under the condition of steel ball submerging by pulverized coal and the condition of pulverized coal pressing by a steel ball can be obtained, and the pulverized coal amount in the coal mill large tank at the moment to bemeasured is obtained; the relation or relation curve and the pulverized coal amount in the coal mill large at the moment to be measured are used for obtaining the surface area of the pulverized coalexposed under the primary air at the moment to be measured; and on the basis of the surface area of the pulverized coal exposed under the primary air at the moment to be measured and the wind amount,the pulverized coal flow in a primary air pulverized coal tube is calculated. Through the method, the pulverized coal tube pulverized coal flow can be more accurately calculated.

Description

technical field [0001] The invention belongs to the technical field of boilers, and in particular relates to a method for obtaining pulverized coal flow in a pulverized pipe in a double-inlet and double-outlet steel ball mill direct blowing pulverization system. Background technique [0002] The real-time amount of fuel entering the furnace of the direct-blown pulverizing system can be calculated at steady state, but during the start-up and shutdown of the pulverizing system, the concentration of pulverized coal in the primary air powder pipe is constantly changing, that is, the amount of fuel entering the furnace is also changing. The accuracy of the amount of fuel entering the furnace directly affects the fuel control command, and inaccurate fuel feedback may lead to the reverse adjustment of the fuel command, resulting in loss of control of the temperature and pressure of the main steam of the boiler, affecting the safety and economy of the unit . Therefore, it is very i...

AI Technical Summary

Problems solved by technology

[0002] The real-time amount of fuel entering the furnace of the direct-blown pulverizing system can be calculated at steady state, but during the start-up and shutdown of the pulverizing system, the concentration of pulverized coal in the primary air powder pipe is constantly changing, that is, the amount of fuel entering the furnace is also changing. The accuracy of the amount of fuel entering the furnace directly affects the fuel control command, and inaccurate fuel feedback may lead to the reverse adjustment of the fuel command, resulting in loss of control of the temperature and pressure of the main steam of the boiler, affecting the safety and economy of the unit

Therefore, it is very important to accurately obtain the concentration / flow rate of pulverized coal in the primary air powder pipe. However, there are currently microwave methods, photoelectric detection methods, laser methods, and electrostatic methods for measuring pulverized coal concentration, but they are not mature enough. There are not many applications, and the effect is not ideal. Each power plant generally adopts a fixed value (0.6-0.85) as the pulverized coal concentration in the primary air powder pipe. , in the start and stop of the coal feeder, especially the start and stop of the coal mill, the change of the pulverized coal concentration is very complicated. There has been no good way to eliminate or minimize the disturbance. Distortion of fuel feedback often occurs, the capacity damper of the coal mill is adjusted in reverse, and the main steam pressure / temperature deviates greatly from the set value, which affects the safety and economy of the unit.

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