S. Hoseinzadeh - Centre for Asset Integrity Management, Department of Mechanical and Aeronautical Engineering, University of Pretoria, Pretoria, South Africa
P. S. Heyns - Centre for Asset Integrity Management, Department of Mechanical and Aeronautical Engineering, University of Pretoria, Pretoria, South Africa

In this paper, a design of a heat exchanger that can be used as a gas boiler investigated. The heat transfer is done with a combination of convection and radiation plus blowing. The equations solved by using the finite volume method (FIM) and the numerical results are compared with experimental data. The effects of the geometric parameters include cold channel width, hot channel width, air intake gaps considered, and thermal performance, dimensionless temperature differences, and heat transfer of flow are studied with Ansys Fluent software. The results show that there is a backflow of combustion products out of the air slots, and the pressure of combustion products increased in the channel. Additionally, the size of the fresh air must be about 3mm to provide fresh air to complete combustion and creating enough space between the higher flames and the combustion products of the low flames.

Combined heat transfer; Combustion products; Heat exchanger designing; Radiation; Turbulent flow