A device and method for synchronously measuring the gas-solid two-phase velocity field of a wall-attached jet

Abstract

The invention discloses a synchronous measuring apparatus and method for a wall jet gas-solid two-phase velocity field. The apparatus comprises a pulverized coal furnace modeling device, waveguide tubes, microwave emitters, an infrared wide-angle lens, a visible wide-angle lens, a high-speed CCD camera, an infrared thermal imager, a pulse laser sheet light source, a polarity particle, a fluorescent particle, a fluorescent particle uniform mixing chamber, a polarity particle uniform mixing chamber, and a computer. In a gas-solid two-phase flow field, the fluorescent particle serves as a tracer particle of wall jet air flows and the polarity particle simulates solid particles in rotating air flows, and a visible image and an infrared image of the two particles are presented by two different optical devices respectively according to the different optical characteristics of the two particles. In this way, the problem of a conventional method that two-phase particles are difficult to separate is solved, and the measuring precision is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of multiphase flow parameter measurement, and in particular relates to a method and device for synchronously measuring the gas-solid two-phase velocity field of a wall-attached jet. Background technique [0002] The swirl burner is the main combustion equipment of the opposed combustion boiler. Its working principle is: under the action of the swirler, the pulverized coal flow will generate a swirling jet after being injected from the nozzle, and then form a high-temperature flue gas backflow area that is conducive to ignition. And make the air flow strongly mixed, prompting the pulverized coal to ignite and burn quickly and stably. However, for the swirl burner near the water wall, the coal powder particles and fly ash particles are easy to deviate from the flow line under the action of centrifugal force and wear the wall surface, especially in the outer recirculation area near the side wall. At the same t...

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Problems solved by technology

However, the current conventional measurement methods, such as PIV particle image velocimetry, can only measure the velocity field information of the single-phase flow field, and the two-phase flow field measurement methods developed based on this are mainly divided into three categories: (1) in the optical Add a filter in front of the lens or use two sets of light sources to take two kinds of particle images separately and then perform single-phase calculation; (2) present the two-phase particles on the same film, and use the interphase dynamic characteristic resolution method to directly contain the two-phase particles (3) Present the two-phase particles on the same film, and then use brightness resolution, particle size resolution, spatial frequency resolution, shape resolution, etc. to separate the two-phase particle images and then perform single-phase operation

Methods (1) and (2) are currently only applicable to gas-liquid two-phase at relatively low speed, while method (3) belongs to the post-separation mode. The biggest disadvantage of this method is that the two-phase particle spots with the same optical performance have mutual interference. It is difficult to distinguish the two-phase particles on the image, which is easy to cause errors

It can be seen that the traditional measurement method cannot realize the separation of gas-solid two-phase particles (gas-phase tracer particles and solid-phase solid particles) at the source

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