Study of heat transfer and pressure drop for novel configurations of helical tube heat exchanger: a numerical and experimental approach

In this study, several unique tube configurations are designed and modeled to examine the thermal and hydraulic performance of a helical tube heat exchanger (HTHE) experimentally and numerically. For cold and hot side tube designs, the numerical investigation is completed using three-dimensional modeling, and the findings are confirmed using experimental data with Reynolds numbers ranging from 16,000 to 25,000. Six configurations named HTHE1, HTHE2, HTHE3, HTHE4, HTHE5, and HTHE6 are tested. The findings showed that as compared to the uniform tube distribution, the new arrangements have a greater overall heat transfer coefficient. The overall heat transfer coefficient has the highest enhancement ratio (125-185%) in the HTHE6 setup with two pathways. Additionally, it is discovered that the pressure drop rises as the Reynolds number increases. The HTHE1 configuration has the highest pressure drop values, whereas configurations with only one pass result in a greater pressure loss when compared to setups with two paths. The values of the coefficient of performance for the HTHE6 are larger than those of other forms, and the coefficient of performance decreases as the Reynolds number increases. The exergy efficiency grows with the rise of Reynolds number where the HTHE6 has the maximum value of exergy efficiency compared to other shapes. The performance of heat transfer is dramatically improved by the novel tube arrangements, although variations in pressure drop and pumping power are only a little affected.