Numerical Investigation of Jet Impingement Cooling with Supercritical Pressure Carbon Dioxide in a Multi-Layer Cold Plate during High Heat Flux

Jet impingement cooling with supercritical pressure carbon dioxide in a multi-layer cold plate during the heat flux of 400 W/cm² is investigated numerically. The generation and distribution of pseudocritical fluid with the high specific heat of supercritical pressure carbon dioxide and the mechanism of the heat transfer enhancement led by the high specific heat are analyzed. For a given nozzle diameter, the effects of the geometric parameters of a multi-layer cold plate such as the relative nozzle-to-plate distance, relative plate thickness, and relative upper fluid thickness on the average heat transfer coefficient are studied. The results show that the target surface is cooled effectively with supercritical pressure carbon dioxide jet impingement cooling. When the radial distance is less than 6 mm, the maximum wall temperature is 368 K, which is 30 K lower than the maximum junction temperature for a silicon-based insulated gate bipolar transistor, a typical electronic power device. There is a pseudocritical fluid layer near the target surface, where specific heat reaches above 34 kJ/(kg·K) locally. The drastic rise of the specific heat leads to obvious heat transfer enhancement. Within a certain range, the local heat transfer coefficient and the specific heat are linearly correlated and Stanton number remains constant over this range. The heat transfer coefficient is at a maximum when the relative nozzle-to-plate distance is 1. As the relative plate thickness increases from 0.5 to 3.5 or the relative upper fluid thickness increases from 0.5 to 2.5, the average heat transfer coefficient decreases monotonically.