Developing an algorithm to evaluate the tube and baffle choice influences on enhancing the hydrothermal performances of shell and tube heat exchangers

At the beginning of a new shell and tube heat exchanger (STHE) design, it is valuable to know which combination of tube and baffle types will yield the highest possible hydrothermal performance, considering all the defined ranges of working conditions. This becomes crucial for the compact STHE, which are extremely squeezed to smaller sizes. This promotes the researchers to develop suitable software, which can largely help the design engineers to make critical decisions at the early stages of their designs. This study extends a hybrid analytical-experimental algorithm, which can greatly help the STHEs’ engineers to readily predict the impact of using disc-doughnut baffle and dimpled tube features on enhancing the hydrothermal performances of their base STHEs, i.e., those equipped with segmental baffles and smooth (or no dimple) tubes. In this regard, a number of analytical-experimental correlations is derived to straightforwardly perform such calculations and readily come to a decision. However, this requires validating the derived correlations against available experimental/numerical data. Because of the complexity of the main STHE configuration and unavailable experimental data, suitable experimental setups are carried out to provide the required database. After ensuring the accuracy of derived correlations, a number of different STHE configurations are modeled and their performances are calculated and compared with each other under various proposed working conditions. The main contribution of this work is that the present developed algorithm can readily find the best combination of tube and baffle types, which leads to optimum hydrothermal performances for the STHE at the proposed working conditions and existing constraints. A guideline is also developed to follow the steps in this algorithm readily. The developed algorithm is suitably examined by testing a complex STHE equipped with various combinations of baffle and tube choices. As the most important finding in these tests, the use of dimpled tubes with either segmental or disc-doughnut baffles can enhance the mean heat transfer rate of the base STHE by about 15.6 and 22.4 %, respectively.