The Analysis of a Cross Flow Heat Exchanger used in a Solar Tunnel Dryer

This paper presents the application of a compact size cross flow heat exchanger used in a solar tunnel dryer as an air heater. A finned type refrigerator condenser acted as a forced convection unit, which was installed between a flat plate solar collector and a drying chamber of a solar tunnel dryer have been experimentally studied. The experimental unit was constructed to test air-water fin-and-tube heat exchanger, together with a description of the numerical calculation. The first preliminary experimental results using single-phase, hot water generated from a receiver tube of a parabolic trough located on a field receiving a direct solar radiation on a sunny day. Parabolic trough focuses direct solar radiation to the receiver tube. Numerical results are presented in detail in order to both complementing the experimental information obtained, and to show its potential as an analysis and calculation. In this paper the thermal performance analysis of a cross flow unmixed heat exchanger performed by the variation of volume fraction of hot fluid, which is a hot water and air where air serves as cold fluid and water serves as a hot fluid. Cross flow heat exchanger was connected with the hot tube of the parabolic trough with a mass flow rate of hot water 0.133 kg/s. Also the volume fraction of air varied in 3 values: 0.0304, 0.0617, and 0.093 kg/s for changing the mass flow rate of air. Experimental results such as heat exchanger effectiveness, overall heat transfer coefficient, heat transfer rates have been calculated for assessing the thermal performance of the heat exchanger, mass flow rate of air and temperature of hot fluid was measured using anemometer and thermocouples respectively. These are variable depending on the inlet and outlet temperature of the fluid and effectiveness. The results indicate that, rate of heat transfer rises when the mass flow rate of air increases, but the effectiveness decline when the mass flow rate of air with increase.