恒温式及绝热式量热法测定煤炭发热量的实验对比研究

Experimental comparative study on determination of calorific value of coal by isothermal calorimetry and adiabatic calorimetry

煤炭发热量是评价燃料煤品质的重要指标及煤炭计价的主要依据,而恒温式与绝热式量热法由于外筒的控温方式和结果计算方法不同,需对其测定精密度与准确度进行实验对比研究,以期对2种方法测定煤炭发热量的实际应用具有指导意义。应用有证煤标准物质及日常检测样品对IKA C6000全能型自动热量计恒温模式及绝热模式下测定煤炭发热量的准确度及精密度进行评价,并从环境温度、热容量标定、充氧时间及充氧压力、仪器维护保养等方面探讨2种模式测定注意事项。结果表明,IKA C6000全能型量热仪恒温模式及绝热模式下的仪器热容量标定结果均符合国标要求;有证煤标准物质及日常煤样的干基高位发热量重复测定标准差均小于国家标准规定的重复测定标准差;2种模式下测定的干基高位发热量结果差值95%置信区间为-84~137 J/g,2种模式下的测定结果没有系统性误差,显示出较高的精密度及准确度。

The calorific value of coal is an important index to evaluate the quality of coal,as well as the main basis of coal valuation.The isothermal calorimetry and adiabatic calorimetry are different due to the temperature control method and calculation method of the results of the outer cylinder.It is necessary to compare the precision and accuracy of the 2 methods in order to guide the practical application of calorific value of coal measurement.The accuracy and precision of isothermal mode and adiabatic mode of IKA C6000 global standard calorimeter were evaluated by using certified standard coal samples and daily testing samples.The ambient temperature,thermal capacity calibration,filling time and filling pressure,instrument maintenance of 2 modes were discussed.The results show that,the thermal capacity calibration of IKA C6000 calorimeter in the isothermal mode and adiabatic mode can meet the requirements of the national standard.The standard deviation of dry-based gross calorific value of certified coal standard materials and coal samples are less than standard deviation specified in the national standard.The 95%confidence interval between the dry-based gross calorific value in both 2 modes is-84~137 J/g.The test results of 2 working modes have no systematic error,and it shows high precision and accuracy.It has important reference value for the determination of coal calorific value and the practical application of the 2 types of calorimeter.