载流法制备硫酸露点腐蚀模拟气体的试验研究

Preparation of Sulfuric Acid Vapor for Simulation of Sulfuric Acid Dew Point Corrosion by Inert Gas Carrying Method

硫酸露点腐蚀是火电厂普遍存在而又棘手的问题,研究其机理、影响因素与防护方法意义重大。目前其研究上面临的主要障碍是如何获得可靠的硫酸露点腐蚀模拟气体,通过分析国内外硫酸露点腐蚀模拟气体产生方法的缺陷,提出了载流法产生模拟气体的方法,即对高浓度硫酸进行加热通N2,把硫酸蒸汽带入露点腐蚀模拟装置中。以电导率、SO42-为监测指标,讨论了硫酸体积、硫酸浓度、加热温度、N2流速对硫酸蒸汽产生效率的影响,结果表明:这是一种获取硫酸露点腐蚀的新方法。同时,以实际燃机电站余热锅炉排气成分为例,验证了该方法的可行性。

Sulfuric acid dew point corrosion is a common and troublesome issue for thermal power plants.Therefore,it is of great significance to clearly understand the relevant mechanism,influencing factors and protection methods.The main obstacle currently encountered for the matter is how to reliably obtain the sulfuric acid gas to simulate the real sulfuric acid dew point corrosion environment.By analyzing the insufficiency of the existed methods for preparation of such gas at home and abroad,a method of introducing the simulated gas into the reaction chamber by inert gas carrier is proposed,namely,with help of a nitrogen steam,the sulfuric acid vapor is brought into the dew point corrosion simulation device.Based on the monitored index of conductivity and SO42-,the effect of sulfuric acid volume,sulfuric acid concentration,heating temperature and N2 flow rate on the production efficiency of sulfuric acid vapor were discussed.The results show that the new method can rightly provide for dew point corrosion of sulfuric acid vapor.At the same time,the feasibility of the method is verified by taking the exhaust gas of the waste heat boiler of the actual gas turbine power station.