Expanded microchannel heat exchanger: Non-destructive evaluation

Recent theoretical developments in expanded microchannel polymer-based heat exchangers were promising, but the initial experiments underperformed simple theory. In order to understand this discrepancy, this paper introduces a nondestructive methodology for characterizing polymer heat exchangers. A computerized tomography (X-ray) scan was performed to diagnose the problem. The method was tested on the expanded microchannel polymer heat exchanger to determine the variations in geometry between the theoretical and experimental heat exchanger. Channels were found to have variable heights causing flow maldistribution. The results are discussed to guide further technological development of this approach to heat exchanger design and fabrication and lays the groundwork for an advanced discretized modeling.