Study And Application Of Two-phase Flow In Coal Powder For GuiYang Power Plant

Recently with the fluidization technical studied deeply, the mechanism of gas-solid flow and the hydro-mechanical behavior and conveying quality of it attracts more and more researcher. It is necessary to make a large of experimental research in order to learn the mechanism of gas-solid flow and the hydro-mechanical behavior and conveying quality of it. At the same gas-solid model, the result of experiments depends on the establishing of many experimental instruments and the rationality of testing method. Therefore, convenient and reliable testing technique of gas-solids flow is a necessary tool in the research of gas-solid flow.At present, direct testing method is mostly applied in gas-solid testing. Though it is relative exact, this method is not so perfect: firstly, applying this method the sampling head tends to disturb the gas-solid flow; secondly, the sampling head may be ablated badly; thirdly, with this method, the value gained is a local one, not a mean one. In this paper, to the primary air conveying power system in power plant powered-coal boiler, a method is raised to measure the section mean temperature through surface-type temperature measuring of the air –powered –coal mixture pipe. Namely, with the foundation of numerical simulation of equal-phase flow model, a mean temperature, the measured result of push –in type measurement is used to testing that of the surface-type measurement.In the numerical simulation, taking the mixing segment of the primary-air conveying powder system as studying object, the equal–phase flow model is used to simulating the flow of primary-air and air-powdered-coal mixture, then the relation is founded of mean temperature in the pipe, and that of the outer-layer of the pipe ,and the result of computation is fit into a formula. With the foundation, the arithmetic and software can be worked out to measure the mean temperature of air-powdered-coal mixture. In the local experimental, aiming at several working condition, the measured result of push-in type measurement is used to test the veracity of the surface-type measurement. As a result, both agree with each other smoothly. So, this software can be used in actual air-distribution testing system to measure various parameters of primary-air conveying powder system.