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【摘要】 采用Fluen软件对封闭腔内Cu-H2O纳米流体强化相变蓄冷进行了数值模拟,重点分析Cu纳米粒子添加量和Gr数对蓄冷性能的影响,并解释其换热机理。研究结果表明:Gr数对其结冰时间影响不大,但纳米流体的质量分数是影响纳米流结冰时间的一个主要因素。对于一给定的Gr数,随着纳米粒子质量分数的增加,结冰时间减少,这是由于纳米流体相比基液具有较高的导热系数。另一方面,由于纳米流体融解潜热降低,则纳米流体结冰时,每单位质量的纳米流体需要的能量较少,所以纳米流体具有较高的热释放率,在相变储能应用中具有巨大优势。 【Abstract】 The cold storage of nanofluids as the phase material in a two-dimensional enclosure was numerically simulated by using fluent software.The effect of copper particle concentration and Grash of number on cold storage properties was investigated.The results indicate that the cold storage properties exhi bit little sensitivity to Grash of number,but the mass fraction of nanoparticle is the main effective factor on cold storage properties.For a given initial Grashof number,as the solid particle mass fraction raised the freezing time decreased because the enhanced thermal conductivity of the nanofluid in comparison was larger than the base liquid.At the same time,with the latent heat of fusion,less energy per unit mass of the nanofluid was needed for freezing the nanofluids.The higher heat observed release rate of the nanofluids is a clear indicator of its great potential for thermal energy storage applications. 【关键词】 Cu-H2O纳米流体; 自然对流; 相变; 蓄冷; 数值模拟 【Key words】 Cu-H2O nanofluids; natural convection; phase change; cold storage; numerical simulation