Enhancing the Energy Efficiency of Heat Exchanger by Using Double Helical Coil in Shell and Tube Heat Exchanger: An Experimental Study

The primary objective of this study is to enhance the energy efficiency of the heat exchanger by utilizing a double-helical coil tube (DHCT). A double helical coil is incorporated into the shell to achieve this goal, as double tube heat exchangers are well-suited for high-temperature and high-pressure applications due to their narrow diameters. Despite being cost-effective, they provide a large surface area for heat transfer. The experimental apparatus was used to calculate the geometric patterns’ impact on the heat transfer rate, employing the NTU (Number of Transfer Units) method. The NTU approach is particularly useful for assessing heat transfer rates in counter-current heat exchangers, especially in cases where there is insufficient data to calculate the log mean temperature difference. In this experiment, double-helical tubes were placed inside the heat exchanger shell to enhance the heat transfer rate. The data was recorded manually and digitally by connecting it to Arduino software using a billboard circuit. The temperature readings were obtained to calculate the heat transfer rates after specific time intervals. The coil's desired inner and outer diameter set at 0.05 m ≤ Di, 0.08 m ≤ Do, tube and shell water flow rates range between 1 and 4 kg/s. After conducting numerous experiments, the result shows that the heat transfer rate for the double-helical coil tube (DHCT) is much greater than for the single helical tubes. The experiment shows that the effectiveness of the heat transfer rate observed with the double-helical coil was 54.33%, whereas, with a single helical coil heat transfer rate was 48.88%. It is proved by experimentation that a double-helical coil tube (DHCT) heat exchanger enhances the energy efficiency of the heat exchanger. The findings offer valuable insights for heat exchanger design optimization, potentially contributing to eco-friendly and more energy-efficient solutions in various industrial applications.