Experimental analysis on pressure loss and heat transfer improvement in an air to water double pipe
heat exchanger is presented. Typical circular-ring (TCR) and perforated circular-ring (PCR) turbulators,
assumed as turbulators. Water and air move through inner and outer pipes, respectively. Experimental
analysis is conducted for various values of open area ratio (0, 0.0208, 0.0416 and 0.0833), Reynolds
number (6000, 8000, 10,000 and 12,000) and pitch ratio (1.83, 2.92 and 5.83). According to experimental
data, correlations for Nusselt number, friction factor and thermal performance are presented as functions
of Reynolds number, pitch ratio and open area ratio. Sensitivity analysis is used to find the effect of each
active parameter. Results indicated that using PCRs leads to obtain lower heat transfer enhancement than
the CRs. Thermal performance increases with increase of open area ratio but it reduces with rise of pitch
ratio and Reynolds number. The most effective parameter for thermal performance is open area ratio
کلید واژگان :
Perforated circular-ring Air to water heat exchanger Turbulator Heat transfer Friction
