Abstract: By means of interpolation based on reduced temperature,a procedure,using the enthalpy chart of petroleum fractions,to determine the enthalpy of saturated vapor and liquid near the critical region,is suggested.1.From the Watson characterization factor K and the specific gravity of the fraction,the pseudocritical temperature T_c is calculated,from which the reduced temperature T_r concerning the operation temperature T,T_r=T/T_r is obtained.2.From the pseudocritical temperatures T'_c obtained from four domes used for interpolation,which are two different API gravities on both of the figures of differing Watson K,the temperatures T' concerning the above reduced temperature T_r can be calculated.Thus,all the chart values at the temperatures T' are obtained.3.After linear interpolation in API gravities for each figure,the desired enthalpy can be obtained by linear interpolation in Watson K.It has been proved that this procedure not only extens the use of petroleum fractions enthalpy chart,but also has higher accuracy and greaterconvenience in use.

摘要： 在石油加工过程设计中,需求算石油馏分的焓值.在工程计算中,常用石油馏分烩图.对于石油焓值的求法,瓦特森(K.M.Watson)和纳尔森(E.F.Nelson)作了先导工作,提出特性因数K表示石油馏分的化学组成特性,用特性因数K和比重SG来关联石油馏分的热性质.