F225 Single-Phase Heat Transfer and Pressure Drop inside Corrugated Tubes for Hot-Water Supply Systems in Low Flow-Rate Region

Abstract

In this study, we investigated means to improve the heat transfer performance on the water side of heat exchangers in hot-water supply systems. And we experimentally verified the pressure drop and the heat transfer in single-phase flow using a smooth tube, a helical-grooved tube, and corrugated tubes with six different corrugation shapes and outside tube diameters of 12.7 mm. The effects of the difference in corrugation pitch and corrugation depth on pressure drop and heat transfer in low flow-rate region were reported and those results clarified the optimum corrugated design.