The Simulation Of Interference Fringe For Binary Gas Diffusion Under High Temperature And High Pressure

Energy is the power of human development, and the combustion is an important technical way to get energy. In combustion reaction, fuel and oxidant pyrolysis products of mass transfer and diffusion, reaction products transport and diffusion have important impact on the combustion process. Binary actual gas diffusion coefficient under the high temperature and high pressure is a kind important parameter of both in research and in industrial production, binary gas diffusion coefficient in scientific research can establish accurate pulverized coal gasification and combustion model for numerical simulation and the guidance experiment; In terms of industrial production Binary actual gas diffusion coefficient can be used to improve coal technology(such as coal gasification, combustion boiler design, etc.).Existing literature, the binary gas diffusion coefficient calculation model is established under the condition of ideal gas state equation, and the binary gas diffusion coefficient estimation under high temperature and high pressure will cause considerable error.Paper firstly summarizes the laser holographic interferometry technique that widely used in scientific research and a large amount advantage of shear laser interferometry in this experiment. Secondly it introduces the main methods to measure the high-pressure binary gas diffusion coefficient,comparatively analyzing their advantages and disadvantages to give some reference value to this paper. After having determined the shearing laser interference method is adopted, in order to adapt to high temperature and high pressure gas atmosphere, we have to improve the spherical valve type double volume diffusion tank and other components; Finally, paper constructs the actual binary gas diffusion coefficient of laser transverse large shear mathematical model of double volume under high temperature and high pressure;In the MATLAB, we can programme to simulate the spread phenomenon of the binary combination gas(O2-CO2, O2-CO2, CO-O2,CO2-CH4 and CO-H2), and output interference fringe; Paper calculates increase a value for interference fringe series as a wholeof the transverse offset s, and restores interference fringeclimate of high pressure components between(0.1 MPa to 5 MPa) and high temperature(1273 k) to get the concentration cloud image of C(x, y) changing with time and location, and extendes the binary gas diffusion coefficient calculation model to high temperature(less than 5 MPa)and high pressure(1273 k), in order to do a bit of theoretical basis for establishing a more accurate pulverized coal gasification and combustion model.The results showe that the large transverse shearing laser interference binary actual gas diffusion coefficient measurement has highprecision, and concentration measurement error is less than 1.07%; This measurement need less precision optical element, and has the most convenient and simple assembly platform, component orientation and system debugging minimalist, so it can well meet the requirements of the experiment; Interference fringes of binary gas density in the initial stage of gas diffusion is most large; With the dual actual gas diffusion, interference fringe density will be smaller,and then larger; finally involved stripes will get more and more sparse; Until the end of the binary actual gas diffusion, the interference fringes will be close to the background. This paper is the assumption that the product ρD of binary gas diffusion coefficient and density is a only temperature related physical quantities as a basis for research, this assumption at the time of high temperature low pressure is established; But under the high pressure high temperature(1273 k), binary gasρD is not a constant that only related to the temperature, it is also need further research.