The work is devoted to the study of the temperature distribution and equivalent voltage on the surface of a thermal radiation receiver during experimental and computational series. The experiments showed a qualitative and quantitative coincidence of the temperature data obtained by thermal imaging with the results of numerical modeling. The average error was 0.5℃, with a maximum deviation of 1.5℃ at individual points, which is due to edge effects and thermal insulation features. The computational model reproduces the main characteristics of the temperature field, including the effect of shielding, using a relatively low density of the computational grid. As part of the verification of the numerical model, the analysis of grid convergence was carried out, as well as the control of residuals and control of solution parameters were performed.

Keywords: heat exchanger, numerical and analytical calculation, convective and radiant heat transfer, efficiency improvement, outgoing flue gas, heat recovery, gas-liquid heat exchanger, numerical modeling, mathematical model, ANSYS Workbench software

The work is devoted to the development and research of a heat exchanger for a contact gas-liquid heat exchanger. To increase the efficiency of heat transfer, the surface receiving heat is equipped with longitudinal fins and transverse partitions that form vortex structures in a turbulent gas flow. The expected decrease in gas temperature is 300-600 °C when cooled with water at a temperature of 50 °C. Simulation modeling has been carried out, including analysis of temperature distribution and hydraulic resistance, thermal power and stresses.

Keywords: heat exchanger, efficiency improvement, exhaust flue gas, heat recovery, mixing heat exchanger, numerical modeling, mathematical model, pixelation method

The work is devoted to ensuring the completeness of mixing of gas coolants into a direct-acting heat exchanger by optimizing the geometry of the mixing chamber, in particular the addition of a funnel. Four funnel configurations in the range of 45°-180° are considered. The problem is solved in a stationary formulation by numerical simulation in the OpenFOAM environment. A 14-fold increase in the uniformity of mixing is shown when using a 45° funnel compared to a cylindrical mixing chamber.

Keywords: heat exchanger, mixing heat exchanger, efficiency improvement, outgoing flue gas, numerical modeling, heat recovery