Development of a New Correlation for Saturated Flow Boiling Heat Transfer in a Helically Coiled Tube

We have developed a heat transfer correlation for saturated flow boiling of water in a helically coiled tube. Initially, we collected experimental data encompassing a broad spectrum of thermal-hydraulic conditions and geometric configurations, and examined the influences of key dimensionless parameters, such as the convection number and the boiling number. The data analysis showed that the observed trend aligns with previous studies on boiling heat transfer within a straight tube. Also, we investigated the influence of centrifugal force acting on the fluid in a helically coiled tube and confirmed its significant impact on boiling heat transfer. Based on our findings, we propose a new heat transfer correlation that incorporates a dimensionless number of the centrifugal force divided by gravitational force. The basic structure of this correlation was adapted from the Kandlikar correlation for saturated flow boiling. The new correlation demonstrated enhanced accuracy compared to existing ones. Additionally, we showed its applicability to boiling heat transfer within a straight tube as well.