The Jatropha biodiesel, swill-cooked dirty oil biodiesel and rubber seed biodiesel were prepared in laboratory by transesterification, and according to the different volume ratio, 36 kinds of biodiesel blend fuels were prepared with the 0# diesel. The theoretical calorific values of blend fuels according to Mendeleevs formula and mass fraction were calculated, and linearly fitted with the mesured calorific value respectively to find out the best calculation method of theoretical calorific value. The results showed that theoretical calorific value according to mass fraction was suitable for the calculation of calorific value of Jatropha biodiesel blend fuel; theoretical calorific value according to Mendeleevs formula was more suitable for the calculation of calorific value of swill-cooked dirty oil biodiesel blend fuel; two kinds of methods were suitable for the calculation of theoretical calorific value of rubber seed biodiesel blend fuel. |