Measuring method and system of blast capacity of inlet of power station coal mill

Abstract

The invention discloses a measuring method and system of the blast capacity of an inlet of a power station coal mill. The method comprises the steps of building a mechanism model of the blast capacityof the inlet, wherein in the mechanism model, there is a corresponding relation between the blast capacity of the inlet and the pressure difference between an outlet and the inlet of the coal mill; determining the ratio coefficient based on calculation of an auxiliary formula of the blast capacity of the inlet of the coal mill, and building an inlet blast capacity mathematical model of the coal mill based on the mechanism model; conducting empirical correction on the inlet blast capacity mathematical model by comparing the model with a hardware measurement value; meanwhile, regarding the inlet blast capacity calibration coefficient as the model gain of the mathematical model. The measuring method is not influenced by factors like on-spot flow fields and pipelines, the reaction is sensitive, the instantaneous change condition of the blast capacity in an air channel of the inlet of the coal mill can be timely reflected, and operating personnel conveniently conduct adjustment and next automatic control; the fault rate is low, the mathematical model is built after a large quantity of experiments and long-term observation, and the measuring precision is high; new measuring points do not need to be arranged, the hardware structure of a coal mill system does not need to be changed either, and the measuring method has universality.

Description

technical field [0001] The invention relates to a method for measuring air volume, in particular to a method and system for measuring air volume at the inlet of a coal pulverizer in a power station. Background technique [0002] With the improvement of automation in thermal power plants, it is of great significance to accurately measure the air volume of each part of the boiler and automatically input each input volume based on the measured air volume, which is of great significance to the safe production and operation of thermal power plants and energy saving and consumption reduction. If the air volume at the coal mill inlet is too large, it will intensify the erosion of the water-cooled wall near the burner, and in severe cases, it will easily cause the boiler tube to burst; The air volume at the inlet of the coal mill does not change proportionally with the adjustment baffle, so it will be difficult to control, and even the coal mill trips due to low primary air volume; ...

AI Technical Summary

Problems solved by technology

[0003] The coal mill air volume measurement device of domestic thermal power coal-fired units has inaccurate measurement and low sensitivity due to various factors such as insufficient straight pipe section, turbulent flow field, easy blockage of devices and pipes, etc.

In the existing technology, a rectification device is installed inside the flue, and it is expected to make the flow field relatively stable and uniform, thereby improving the accuracy of the air volume measurement of the coal mill. However, the rectification effect of the rectification device depends on the design level of the device. The inhomogeneity of the fluid flow rate inside the flue is still very large, and the data is easily distorted on the basis of the non-online rapping device and backflushing technology, and the accuracy of the air volume measurement of the coal mill cannot be significantly improved

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