TESTING OF AIR HEATERS WITH PLATE FINNED TUBES WITH SPRAY COOLING

Abstract

This paper deals with the procedure for measuring the relevant parameters of plate-finned tube heat exchangers operating as an air heaters. Besides the description of the experimental installation, the most important geometric characteristics of these appliances are given. In order to determine the relevant parameters for dry and wet regimes (for cases with and without spray cooling), experimental measurements of the heat and hydraulic performance of the heat exchangers were made. Water flowed through the pipes as a warmer fluid. During the experiments, the flow rates and temperatures of the working fluids were varied within the limits defined by the operating parameters of the installation itself, sufficient to allow the obtained results to be generalized. The experimental data were processed by appropriate statistical methods; the aim was to determine equations suitable for engineering practice. The coefficients of the air-side heat and mass transfer and friction factor are defined on the complex geometry of this type of heat exchangers under realistic operating conditions, as a function of the relevant similarity criteria.