煤样制备条件对煤粉水分取值的影响

INFLUENCE OF SAMPLE PREPARATION CONDITION UPON THE EVALUATION OF WATER CONTENT IN PULVERIZED COAL FROM COAL MILLS

煤粉水分通常使用空气干燥基(空干基)水分Mad来估算。由于煤样制备时其水分随着试样所在环境的空气温度、湿度而变化,导致煤粉水分取值存在较大差异,从而影响磨煤机干燥出力的准确计算。通过改变温度、湿度等试验条件,对国内部分发电用煤进行试验研究,获得不同试验条件下各种煤的Mad变化规律。提出在特定温度、湿度条件下进行空干基煤样制备,以获得准确的煤粉水分值。

The water content in pulverized coal is generally evaluated by using water content with air drying basis Mad.In view of the water content varies as the air temperature and humidity being changed in the case of coal sample preparation,leading to comparative large difference existing in evaluation of water content of pulverized coal,thereby affecting accurate calculation of the dry output capcity for the coal mill.Through changing the test condition,i.e.temperature and humidity of air,a part of fuel coal used in domestic power plants has been tested and studied,the regularity of Mad variation for different coal sorts under different test condition being obtained.The preparation of coal sample with air drying basis under specially defined temperature and humidity condition has been put forward,so as to obtain the accurate water content.