The results of the experiment-calculated study of heat transfer of nanofluids forced convection in the recuperative heat exchanger were set out. The experiments for distilled water and one per cent Al2O3-based nanofluid were carried out. The Reynolds number in the experiments varied from 800 to 6500. 20 per cent intensification of heat transfer in laminar flow were shown. Numerical model describing heat and mass transfer processes, based on the hydrodynamic approach, which implies a solution of the Navier-Stokes and energy conservation equations was used for the calculation. Zonal two-equation model of Menter SST was used for calculation of turbulent flow. Satisfactory agreement with experiment was obtained.