摘要
Abstract
Generally,the generation unit is started from cold state by means of pressure method.However,when this method is applied in supercritical boiler,it is inevitable that convective heating surface will be heated dry without steam and,then cooled down with steam.As a result the oxide scales will have to withstand the thermal stress from about 100 cooling temperature difference,which can cause the oxide scales flaking.In this paper,the vacuum method is adopted to start the unit.The low temperature saturated steam flows the heated surface of the boiler before ignition,which can effectively avoid the peeling offofthe oxide scales during the startup process.corresponding experimental study is carried out in No.2 boiler in Changsha Power Station Co.,Ltd of Hunan CHD and satisfactory results are obtained.The temperature difference of the heating surface is significantly reduced before and after the ignition of the boiler,which effectively diminishes the risk of oxide scales flaking.The method is simple and reliable with no equipment modification needed.关键词
超临界机组/锅炉/真空法启动/氧化膜/热应力/过热器管Key words
supercritical unit/boiler/vacuum method/oxide scales/thermal stress/superheater tube分类
能源科技
