【摘要】 研究纳米流体在车用热交换器中的强化传热效果,测试不同纳米粒子体积分数的氧化铝纳米流体在板翅式机油冷却器中的传热和流动特性,并与水、防冻液(乙二醇)及纳米流体基础液体进行对比.试验结果表明,在同一热交换器中,纳米流体的传热系数明显高于其他3种液体.当冷、热侧介质温度为90和120℃时,纳米粒子体积分数为5%的纳米流体的传热系数分别比水、乙二醇和基础液体提高6.52%、18.88%和24.62%;当冷、热侧介质温度为120和135℃时,体积分数为5%的纳米流体的传热系数比体积分数为1%的纳米流体提高104.72%.在试验条件下,热交换器的换热量随纳米粒子体积分数的增大而增大,但流动阻力并未明显增加,初步证明了纳米流体应用于车用热交换器的可行性.更多还原

【Abstract】 In order to study the heat transfer enhancement of nanofluids in a vehicle heat exchanger (a plate-fin oil cooler),the heat transfer and flow characteristics of alumina nanofluids with different volume fractions were measured and compared to those of water,antifreeze (ethylene glycol) and nanofluids’ base fluid.Experimental results showed that in the same heat exchanger,the heat transfer coefficient of nanofluids was significantly higher than that of the other three liquids.When the hot/cold side temperature was 90 ℃/120 ℃,the heat transfer coefficient of 5% (nanoparticle volume fraction) nanofluid increased by 6.52%,18.88% and 24.62% respectively than that of pure water,antifreeze (ethylene glycol) and base fluid;when the hot/cold side temperature was 120 ℃ /135 ℃,it was 104.72% higher than that of the 1% nanofluid.In the experimental condition,the heat flow increased with the nanoparticle volume fraction,but the flow resistance rose moderately,which primarily proved the feasibility of the nanofluids in the vehicle heat exchanger.更多还原