Investigation of turbulent heat exchange in pipes with an allowance for the temperature dependence of the caloric properties of the liquid constitutes a pressing problem, especially in connection with the possibil- ity of using high-boiling organic liquids as coolants in nuclear power plants.

We shall now turn to the theoretical analysis of heat exchange with an allowance for the variability of the liquid's physical properties over the flow cross section. Depending on the temperature, only the viscosity changes considerably in many liquids that are not close to the critical state. In this ease, for calculating the dimensionless heat transfer coefficients, we use the well known integral relationship [3], which assumes the following form if the Prandtl turbulence number is equal to unity: i