Experimental Characterization of a Manifold-Microchannel Heat Exchanger Fabricated Based on Additive Manufacturing

Air-cooled heat exchangers have gained much attention as an alternative for cooling systems in power plants. However, due to lower specific heat of air compared to water larger cooling facilities with excess compressing powers are required in air-cooled systems. Improving heat transfer performance of air-cooled systems can make them more appealing to the market. This requires design and fabrication of complex heat exchanger geometries which can be done by additive manufacturing technology. In this study, a metallic manifold-microchannel heat exchanger was designed and fabricated based on direct metal laser sintering technology. The heat exchanger was fabricated from stainless steel with an overall dimension of 64.2 ×46.0×27.1 mm. Air-side heat flow rate, air-side base convection heat transfer coefficient, and air-side pressure drop were evaluated for different air flow rates. The highest air-side heat flow rate achieved was around 300 W at 14.1 l/s air flow rate. This heat flow rate resulted in an air-side base convection heat transfer coefficient around 1,600 W/m
²
K. The highest air-side pressure drop was measured around 3,450 Pa which occurred at 14.1 l/s air flow rate. This study is the basis of further studies on the heat transfer characteristics of additively manufactured heat exchangers. Modified manifold-microchannels heat exchangers will be tested and compared with the original heat exchanger in future studies.