Numerical simulation method is based on mathematical models of physical processes, whichdescribe run of a given process with a various accuracy. This paper presents a method forelaborating the computer simulation models based on differential equations. This makes itpossible to obtain a high accuracy of representing dynamic features of a real process. Thederived results are given in the form of numerical series. An example of modelling thedynamics of heat transfer through a flat wall is presented in the second part of the paper.Basing on the model one can simulate the process of operation of ship engine as well assuch auxiliary devices as a cooler, evaporator, condenser, tank heating system etc