Experimental study on performance comparison of R410A saturated flow boiling in 3D printed and extruded micro-channel tubes.

This study experimentally investigates the dryout characteristics of saturated flow boiling of R410A in micro-channels, comparing the heat transfer performance of 3D printed and extruded tubes. Experiments were conducted at mass fluxes of 400 and 500 kg/m²s, heat fluxes of 7 kW/m² and 9 kW/m², and a saturation temperature of 5°C. By precisely controlling the inlet vapor quality, dryout phenomena were accurately measured and analyzed. Results indicate that the dryout onset in 3D printed micro-channels is delayed compared to extruded tubes. Quantitatively, the 3D printed tube demonstrates a maximum HTC enhancement of approximately 7.92% and a delayed dryout quality by about 5.26% relative to the extruded tube. Additionally, mass flux exhibits different effects on dryout: a negative feedback effect in extruded tubes and a positive feedback effect in 3D printed tubes. Moreover, higher heat flux accelerates dryout in both tube types. This study provides key insights into two-phase flow mechanisms and enhances the understanding of flow boiling and dryout in micro-channels, offering essential data for optimizing micro-channel heat exchanger design in engineering applications.