EXPERIMENTAL AND NUMERICAL EVALUATION OF DOUBLE COIL PIPES HEAT EXCHANGER

Abstract

Abstract In the current work, substantial research and cost-effective strategy have been conducted to enhance the thermal efficiency of shell and coil heat exchangers, and geometrical modification is one technique to improve the exchange of thermal energy between two or more fluids. Several studies have emerged about enhancing heat transfer with helical coils widely used in industrial applications such as chemical processes, power generation, electronics, etc. Initially, a practical experiment to check results of the numerical analysis on a double coil heat exchanger has been conducted. The results of the numerical study showed high agreement with the experimental results. The numerical analysis was conducted to find the impact of using double coil heat exchanger with multiple pitches on the ability of the exchanger to improve the heat transfer process. The main objective of this simulation is to determine the appropriate configuration of the shell and helical tube heat exchanger to obtain high thermal performance. Following the encouraging simulation results, a double coiled tube with multiple pitches was manufactured, as well as a single coiled tube, to compare the results and confirm the effectiveness of the correlation between the changes in the pitch, while maintaining the basic design parameters in terms of tube diameter ( ), shell diameter ( ) height of shell ( ) and, the height of coil ( ). The numerical study showed high agreement with the experimental data, with the error rate being about 9%. The results showed that at the same length of the tube, the use of the double tube led to an improvement in the heat transfer process, as the improvement rate in the average heat transfer coefficient was 10% compared to the single coil. In general, the new double-tube design (P-2P-P) has led to an improvement in the heat transfer process (5%), which is evident from the increase in the efficiency of the exchanger, the overall heat transfer coefficient, and the preparation of the Nusselt number for the shell side when preparing Reynolds (400 < < 2000) by 26%, 22%, 19%, respectively.