Effect of the header pressure drop induced flow maldistribution on the microchannel evaporator performance

Maldistribution in air–water heat pump evaporators. Part 1: Effects on evaporator, heat pump and system level

“…The impact of these effects varies with heat exchanger size, geometry and operating conditions and may be outbalanced or aggravated by a combination of different effects. A large part of the research on evaporator maldistribution focuses on distribution issues in compact heat exchangers with inlet manifold connected to parallel tubes (Brix et al, 2009;Hwang et al, 2007;Tuo and Hrnjak, 2013;Vist and Pettersen, 2004). Maldistribution in round tube-and-fin evaporators with a distributor at the inlet is mostly investigated by artificially inducing non-uniform flows.…”

Design, fabrication and test of an integrated multi-microchannel heat sink for electronics cooling

“…Additional uneven pressure difference across each tube may also be caused by defects on the tube-manifold and inlet contractions and would be perceived in the temperature distributions for single phase conditions, as reported by Ghani et al [28] and Tuo and Hrnjak [29].…”

Selected studies of flow maldistribution in a minichannel plate heat exchanger

“…It corresponds with other authors' observations, that is to reduce the flow maldistribution, the effect of inertia should be reduced and the effect of viscosity should be increased. Hence, larger pressure drop should be in the channels and lower in inlet and outlet manifold [31,36,37,39].…”

“…Hence, many papers are focused on a numerical simulations as a predictive tool for flow distribution in parallel micro-or minichannels. Tuo and Hrnjak [31] modeled a microchannel evaporator with a consideration that every single microchannel is a unique flow path and that various pressure drops along each flow path must add up to the same overall pressure drop. Comparison of predicted and measured evaporator cooling capacity shows that nearly 88% of the data points are predicted within ±5% deviation from the experimental re-sults.…”