Research Of Radiative Behavior On Gas Radiation Directional Device

In the industrial heating and drying areas, all kinds of electric or gas-fired radiators are widely used, but the energy uniform heating rate is very low when radiant energy heats objects. Therefore, the research of directionality and uniformity of radiation is important to improve energy uniform heating rate, and it is coincident with the sustainable development strategy of energy saving in our country.The Monte-Carlo method based on the concept of RD (radiation energy absorption distribution factor) is used in this thesis. It is proposed that radiation energy distribution rate, equivalent directional emittance and radiation energy collimation rate (RECR), etc, are taken advantage to express the directionality of radiation. One-dimensional steady state heat transfer equation of a tube wall and its inner air are provided, and then combining with the finite difference method solves the temperatures for the kind of radiative duct, at radiation and convection non-linear boundary condition. It analyses the influences of related parameters on a non-isothermal square-tube cavity, such as the depth-to-equivalent-radius ratio, the inside surface emissivity, the air velocity inside tubes, the surface temperature of gas-fired radiant burner, and the ratio of specular reflective surface to diffusely reflective surface. On the basis of researches in a single square-tube, it also studies the irradiation and the uniformity along the object surface. The parameters that influences the irradiation and the uniformity include depth-to-equivalent-radius ratio of the square-tube bundle, the distance between two tubes, and heating distance (the distance between the burner end and the object surface),etc. This paper also learns the differences of the directionality of radiant energy and irradiance uniformity between the different directional devices. Finally, based on the theory, it designs and builds the test-bed which is used to study the radiative behavior of gas-fired radiation directional devices. Then this paper does some experiment simply on the directional devices that have made.