Experimental Study on Heat Transfer and Pressure Drop of Two-Phase Flow across Tube Bundles

- The refrigerant two-phase flow across tube bundles is widely used. Its heat transfer mechanism needs to be further studied. An experimental system was established for measuring heat transfer coefficients, pressure drop and observing flow patterns. The test section of tube bundles was designed. R1233zd as a new environmentally friendly refrigerant was used as the working fluid. The effects of vapor quality, heat flux and mass flow rate on heat transfer and pressure drop were analyzed. The falling film flow, bubbly flow and shear flow were observed. With the increasing vapor quality and heat flux, the heat transfer coefficient increases. With the increasing vapor quality and mass flow rate, the pressure drop increases.