【摘要】 在制冷系统中应用纳米材料是提高制冷机效率和可靠性的重要途径。将纳米材料应用到制冷系统中,需要将纳米粉体在冷冻机油或制冷剂中进行分散。总结了纳米粉体在冷冻机油中的分散稳定性的机理。分析了纳米粒子之间及纳米粒子与冷冻机油之间的作用势能与材质的Hamaker常数之间的关系,建立了冷冻机油中表面修饰后的纳米粒子之间作用势能的修正式,提出了纳米粉体基质材料的选择、粉体制备及其表面改性的原则。制备出纳米NiFe2O4冷冻机油,并通过吸光度/透光率随时间的变化考察了其稳定性。室温陈化140 d后,浓度为3 g.L-1的纳米NiFe2O4冷冻机油的吸光度由3.124降为3.088,衰减幅度为1.15%。更多还原

【Abstract】 Application of nano-particles in refrigerating system is considered to be potential way to improve refrigerating facilities’energy efficiency and reliability.It is essential to disperse the nano-powders in refrigeration oil or in refrigerant.Mechanisms of nano-particles in refrigeration oil were summed up.The modified functions of potential energy between nano-particles,after surface modified,in refrigeration oil with Hamaker constants of the materials were established.The principle to select the substrate materials of the nano-particles and its preparation as well as its surface modification was presented.Furthermore,the new nano-NiFe2O4 refrigeration lubricant oil(NRLO)was prepared.The dispersion stability of nano-NiFe2O4 in refrigeration lubricant oil was experimentally investigated by employing ultraviolet and visible spectrophotometer.The absorbency of the NRLO,with the initial 3 g·L-1 concentration of nano-NiFe2O4particles in oil,changes from 3.124 to 3.088,after the new NRLO was placed for 140 d at room temperature.更多还原