回转式空气预热器是大中型电站锅炉上广泛采用的尾部换热设备,漏风率高是该类设备的致命缺点,降低了电厂的经济效益。所以在回转式空气预热器技术中,防止或降低漏风即密封技术占有很重要的地位。文中分析了其漏风因素及现行密封形式的优缺点,提出回转式空气预热器“单密封”向“双密封”形式改进的理论依据及可行性研究。通过对发电厂实际改进后所带来的经济效益表明,此项措施是改善回转式空气预热器漏风大的有效方案。 Rotary air preheater is widely used in large and medium-sized power station boiler tail heat transfer equipment, air leakage rate is a fatal shortcoming of such equipment, reducing the economic benefits of power plants. Therefore, in the rotary air preheater technology, to prevent or reduce leakage that seal technology occupies a very important position. In this paper, the factors that lead to air leakage and the advantages and disadvantages of the current seal are analyzed. The theoretical basis and feasibility of the improvement from “single seal” to “double seal” of the rotary air preheater are proposed. Through the actual improvement of power plants brought about by the economic benefits show that this measure is to improve the rotary air preheater large effective air leakage.