Condensation heat transfer and pressure drop characteristics of R-134a in an annular helical pipe

Condensation heat transfer and pressure drop data of R-134a in annular helical pipes is of significant importance to the effective design and reliable operation of helical pipe heat exchangers for refrigeration, air-conditioning, and many other applications. This paper presents the experimental investigation on condensation heat transfer and pressure drop characteristics of R-134a in an annular helical pipe. The average condensation heat transfer coefficients and pressure drops were experimentally determined for R-134a at three different saturated temperatures (35 °C, 40 °C, and 46 °C). The experimental results are compared with the data available in the literature for helical and straight pipes.