Results of numerical and experimental study of the heat exchange process are considered as applied to the calculation of helical heat exchangers operating under conditions of unavoidable formation of the solid phase of the heat carrier in the intertube space. Based on the developed physical model of uniform icing, the system of differential equations that describes heat exchange in a two-flow apparatus is integrated. Comparison of the results obtained and experimental data shows that there is a limitation on the application of the model of uniform icing.