流体载热远红外气相辐射加热效果及影响因素研究

On the heating effect and the influential factors of the far-infrared radiation gaseous heating by heat carrying fluid

在"选择性催化还原法(SCR)脱硝-湿法脱硫"系统中,用SCR脱硝后回收的部分废热作为低温热源对湿法脱硫后的烟气进行远红外气相辐射加热,则可实现低成本、高效、简便的烟气再热。以导热油为载热流体,对远红外气相辐射加热湿法脱硫烟气的效果及其影响因素进行了研究。结果表明:流体载热远红外气相辐射加热方式较传统加热方式效果明显;加热终温随导热油温度和进口气体温度升高而升高,而随辐射距离、进口气体流量增大而降低;加热速率随导热油温度升高而增大,而随辐射距离、进口气体温度和进口气体流量增加而减小;加热管所涂涂料的性能是影响辐射加热效果的重要因素之一。

This paper is focused on reporting some experimental results of reheating the flue gas as a result of wet desulphurization with far-infrared radiation by heat carrying fluid,so as to help to solve problems like the environmental pollution and corrosion of the flue and chimney likely to be caused by the direct discharge of the wet flue gas. The experiments we have managed to conduct are aimed at exploring the heating effect and influential factors of the far-infrared radiation heating by heat carrying fluid. In the experiment,we have done a simulated research with the flue gas that is exhausted from the wet desulphurization device,when entering into the heating tank and then being heated by the radiation tube,which tends to take the conduction oil used for the simulation of the waste heat in the actual application as heat carrying fluid. In the experiments,what we have mainly done is to find the influential factors that may affect the heating effects of the farinfrared radiation heating by heat carrying fluid,such as the infrared radiation coatings,the radiation distance,the temperature of the conduction oil,the temperature and flow of the entrance gas. In doing so,we have chosen the terminal heating temperature and the heating rate as the evaluation indexes of the thermos effect. The results of our experiments show that,under the same conditions,when compared with the traditional heating methods,the terminal heating temperature with far-infrared radiation heating method has a maximum increase of 5 ℃. Therefore,more remarkable advantages can be found by using the new heating methods. Thus,it can be concluded that it is possible for the terminal heating temperature to increase with the rise of the temperatures of the conduction oil and the entering gas,whereas it may help to decrease the temperature with the increase of the radiation distance and gas flow. The heating rate increases with the rise of the temperature of conduction oil,but it decreases with the rise of radiation distance,the temperature of entrance gas and gas flow.In addition,the performance of the radiation coating serves also as one of the most important factors that may affect the heating effect of radiation.