利用摩尔折射度的基团加和性,推导出烃类及其混合物的总热值和净热值与其折光指数n、密度d、平均分子量M间的关联式。用大庆原油的十八个馏分检验了它的准确性,并确定了关联式中的参数。利用此关联式可方便地由烃类混合物或纯烃类化合物的n、d、M数据较精确地求得相应的热值或△H_c~0。 Based on the group additivity of the molar refractive index, the relation between the total calorific value and the net calorific value of hydrocarbons and their mixtures and their refractive index n, density d, and average molecular weight M is deduced. The 18 fractions of Daqing crude oil were tested for their accuracy and the parameters in the correlation were determined. Using this correlation, it is easy to obtain the corresponding calorific value or ΔH_c ~ 0 from the n, d, M data of hydrocarbon mixtures or pure hydrocarbons.