Effect of Heat-Exchange Pin-Fin Structure Parameters on its Performance Characteristics

Creating pin-fins on heat exchanger's cold plates is a promising way of improving their efficiency. Pin-fin heat exchangers are widely used in liquid cooling systems for electronic, high-current equipment, etc. Deformational cutting technology (DC) is a proven method for productive fabrication of high-density pin-fin structures. The pin-fins are produced by additional machining of the previously finned surface with а DC tool. Pin-fin structure's surface area, obtained by DC, can exceed 7-10 times its original surface area. DC provides a variety of different pin-fin shapes and structure's geometrical parameters. Finding an optimal relative position and pin-fin parameters is an acute problem. The article gives the technique and the results of comparative experiments on convective heat exchange of pin-fin structures. We conducted the experiments on a test bench that simulated liquid cooling system operation taking into consideration the effect of structure's density, pin-fin shape and verticality and the coolant flow direction on cooled element temperature and structure's pressure drop. In our work we tested pin-fin structures, obtained by DC, with spiral, needle-shaped and hook-shaped pins, height of 1,9-5,1 mm and pitch of 0,6-2 mm. Findings of the research show that the structure with 71 more vertical needle-shaped pin-fin per square centimeter presents better performance characteristics. No significant effect of coolant flow direction on cooled element temperature and structure's pressure drop was detected.

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