【摘要】 对电加热器中纳米流体的传热效果进行了实验研究,采用两步法制备Fe₃O₄^-水纳米流体。此外,还研究了质量分数为0.1%～2.0%的Fe₃O₄^-水纳米流体在有/无磁场作用下对电加热器换热效率的影响,探讨了磁场作用下纳米流体的强化换热机理。结果表明,与基液（去离子水）相比,无磁场时质量分数为1.0%的Fe₃O₄^-水纳米流体可使环境温度提升18.2%;在外磁场作用下,质量分数为1.0%的Fe₃O₄^-水纳米流体可使环境温度提升35.1%。研究结果可为纳米流体在电加热器中的强化传热研究提供重要参考。更多还原

【Abstract】 The heat transfer effect of nanofluid in electric heater was studied. Fe₃O₄^- water nanofluid was prepared by two-step method. The effect of Fe₃O₄^- water nanofluid with various nanoparticle concentrations（mass fraction of 0.1%～2.0%） on heating efficiency of the electric heater with or without magnetic field was studied. Mechanism of enhanced heat transfer by Fe₃O₄^- water nanofluids under a magnetic field was also discussed. Results show that the Fe₃O₄^- water nanofluid with a mass fraction of 1.0%obtains 18.2% enhancement of heat transfer on environment temperature compares to without a magnetic field. The Fe₃O₄^- water nanofluid with a mass fraction of 1.0% obtains 35.1% enhancement of heat transfer on environment temperature with an external magnetic field. This research provides an important reference for enhancements of natural convective heat transfer in nanofluid applications.更多还原