Experimental Study of the New Bayonet Heat Exchanger

摘要

An experimental study is conducted to investigate the heat transfer and the pressure drop properties of a single-phase flow in a bayonet tube heat exchanger. A bayonet tube heat exchanger has only one circulating fluid, i.e.,tap water. The circulating fluid is supplied at an ambient temperature (cold medium) and, as a result, it will be heated by an electrical heater (heat source). The bayonet tube heat exchanger is a two-pass heat exchanger. Different experiments were performed to show the relationships and the effects of different parameters such as the Reynolds number, friction factor, Nusselt number, overall heat transfer coefficient, and effectiveness on the purposed heat exchanger. To enhance the heat transfer rates, a helical tape is installed in the annulus between the inner and outer tube. The flow is considered as turbulent in both the plain tube and the helical tape. The recorded Nusselt number for heat exchanger with the helical tape is about 35.6% higher than that without helical tape. In addition, the helical tape increased the effectiveness by approximately 30.2%.