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

•Designed, fabricated, and tested a flat plate manifold microchannel heat exchanger.•Developed a specially designed manifold to allow distribution of the flow.•Achieved heat transfer coefficients as high as 66,000 W/m2K for water.•Demonstrated reasonable agreement between the experimental and the numerical results.•Potential use is in process, air conditioning and refrigeration applications. 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/m2K 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 ε-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.