Structure and geometric dimension optimization of interlaced microchannel for heat transfer performance enhancement

Abstract

A novel interlaced microchannel is designed, and two side walls of the microchannel are served as the main heat transfer surface. The thermal and hydraulic performance of the interlaced and parallel microchannels are numerically investigated using the full-size conjugate heat transfer model, and then are compared with the experimental results. The optimized geometric dimensions of the interlaced microchannel including the depth, width and spacing are obtained. The results show that the maximum surface temperature deviation between the simulation and experiment of the interlaced and parallel microchannel are only 4.8% and 4.7%, respectively. When the cold water flow rate is 600 ml/min, the Nusselt number of the interlaced microchannel is increased by 65.4% compared to the parallel microchannel, and the JF factor reaches 1.438. The uniform surface temperature of the interlaced microchannel is obtained with a maximum temperature difference of 40 °C, which is lower than that of 50 °C in the parallel microchannel. The thermal and hydraulic performance of the interlaced microchannel are improved with the increase of the depth and width of microchannel due to the heat transfer area in the first and second heat transfer directions are increased. However, a large amount of cold water in the central position of the microchannel can’t participate in the heat transfer because of its larger depth and width, so 1.5 mm and 0.5 mm are selected as the optimized depth and width, respectively. Also, it is found that the spacing of microchannel has little effect on the thermal and hydraulic performance. Considering to the compactness and strength, 0.5 mm is the optimized spacing for heat transfer performance enhancement.