Investigation of heat transfer characteristics of deflected elliptical-tube heat exchanger in closed-circuit cooling towers

Abstract

The core component in a closed-circuit cooling tower is the heat exchanger consisting of bundles of heat transfer tubes. To improve the heat transfer performance of closed-circuit cooling towers, this paper studies the elliptical-tube heat exchanger in closed-circuit cooling towers and proposes a deflected elliptical tube and its optimized tube. This study uses a combination of experiments and simulations to experimentally compare the heat transfer performance of elliptical tube heat exchangers in closed-circuit cooling towers under different operating conditions and simulation comparison and analysis of different wind speeds, spray water flow rate under the influence of the three elliptical tube flow field characteristics and heat transfer performance. The results show that in the wind speed of 2–3.2 m/s, due to the shortening of the tube bundle spacing, the growth rate of the heat transfer coefficient of the elliptical deflection optimized tube bundle is 16.27 %. The heat transfer performance of the deflected elliptical optimized tube is better than that of the elliptical tube and deflected elliptical tube, while the application of the optimized tubes shortens the overall unit structure by 24.03 %, which can reduce the material consumption of the closed cooling tower.