Heat transfer and pressure drop characteristics of a flat plate manifold microchannel heat exchanger in counter flow configuration

The design and performance testing of a single-phase, flat plate, manifold microchannel heat exchanger with water as the working fluid are discussed in this paper. The aim of this study was to explore the use of manifolding of microchannels for performance enhancement of plate heat exchangers for single-phase, low heat flux (process type) applications operating in a counter flow configuration. The paper discusses the design of the heat exchanger, followed by the experimental testing and numerical simulation results. The experimental tests reveal that the heat exchanger is capable of delivering an overall heat transfer coefficient of close to 20,000 W/m(2)K at flow rates as low as 20 g/s (corresponding to a microchannel Reynolds number of 30) and a pressure drop per length value of 5.85 bar/m. The experimental results also are compared with established counter flow heat exchanger epsilon-NTU correlations to verify counter flow performance. Further, numerical simulation results for a single unit cell of the same geometry, which show reasonable agreement with the experimental results, are also described in this paper. The current work demonstrates successful use of microgrooves/microchannels for performance enhancement of plate heat exchangers for diverse industrial applications, including the refrigeration/air conditioning, process, and power production sectors. (C) 2016 Elsevier Ltd. All rights reserved.