Cooling heat transfer of supercritical CO2 in spiral grooved tube heat exchanger
In order to study the cooling heat transfer characteristics of SCO2 in spiral grooved tube heat exchanger,the cool-ing heat transfer coefficient and turbulent kinetic energy of SCO2 flowing in different channels were studied under the conditions of various density of heat flow rate by numerical simulation method.A comprehensive evaluation factor EFwas proposed from the perspective of pressure drop and heat transfer coefficient to reasonably evaluate the comprehensive performance of flow cooling heat transfer under different working conditions.The results show that the heat transfer coefficient of SCO2 is mainly affected by specific heat at constant pressure and the turbulent kinetic energy.When SCO2 flows in the inner tube channel,the heat transfer coefficient is low,but the pressure drop is small,so the comprehensive evaluation factor EF is large.At the same time,in the studied working conditions,the optimal density of heat flow rate is-40 000 W/m2.So that the maximum EF value is 2.00 126.At this time,the comprehensive performance of SCO2 cooling heat transfer is optimal.
Heat transferSupercritical CO2Density of heat flow rateCoefficient of heat transferNumerical simulation
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