Abstract: In this paper, the methods for the evaluation of the waste heat power recovery are analyzed in comparison, and the total net gain within the service life of the equipments M[yuan]is prefered as an economic index, The parameter a, defined by the equation (8), is suggested as a criterian for the selection of the working substances,The optimization of the energy planning with consideration of various factors are well discussed, as shown in Figs. 3, 4, 5and6.