【作者】 娄江峰；

【导师】 王瑞祥；

【作者基本信息】 北京建筑工程学院 ， 供热、供燃气、通风及空调工程， 2011， 硕士

【摘要】 在蒸气压缩式制冷系统运行过程中,冷冻机油起着压缩机内部润滑和密封的作用,且与制冷剂一起循环。采用合适的纳米冷冻机油,有助于改善压缩机摩擦表面的润滑性能和含油制冷剂的传热性能,进而提高制冷装置的能效比和可靠性。含有纳米冷冻机油后,制冷剂的热物性（如饱和蒸气压）将发生变化,影响到制冷系统的性能。本文工作的主要目的是通过测试分析含有纳米冷冻机油后制冷剂的饱和压力的变化,探讨纳米冷冻机油对制冷剂饱和蒸气压的作用机理,对实验结果进行关联。完成的主要工作及获得的主要结论包括:1.纳米冷冻机油的配制与性质研究。配制出添加纳米NiFe₂O₄、富勒烯以及混合纳米粉体的纳米冷冻机油并利用傅里叶变换红外光谱仪对其性质进行了研究。研究发现:1)采用吐温和司盘复配的方法,可配制出稳定性较好的环烷基的纳米NiFe₂O₄、富勒烯以及混合纳米粉体的纳米冷冻机油;2)纳米粉体和分散剂可导致冷冻机油部分吸收特征峰发生变化。如按照一定的方法添加Span80和纳米NiFe₂O₄后,可使矿物基冷冻机油3GS的红外光谱中产生与160SZ相似的脂肪族酸、脂肪族醚和脂肪族伯醇的红外特征峰。这些特征峰对应的官能团是改善3GS和R134a相溶性的主要因素。2.含有纳米冷冻机油后制冷剂的饱和蒸气压的实验研究。测量了含油率为1⁹wt%,温度范围为263³33K的含油制冷剂和含纳米油制冷剂的饱和蒸气压。研究发现:1)在相同的含油率下,含油制冷剂饱和蒸气压偏差随着温度的升高而增大;2)在相同的含油率下,冷冻机油KT56对R22制冷剂饱和蒸气压的影响明显大于3GS的影响,表明KT56/R22的互溶解性大于3GS/R22;3)在相同的含油率下,KT56基纳米冷冻机油对R22制冷剂饱和蒸气压的影响明显大于纯KT56的影响,表明KT56基纳米冷冻机油/R22的互溶解性大于KT56/R22;3.对含油制冷剂饱和蒸气压的实验结果进行关联。工作成果包括:1)结合Xiang方程和Cavestri方程,新提出了一个可描述含油制冷剂饱和蒸气压的方程,采用非线性最小二乘法拟合方程参数,并且对含油率为1%、3%、5%时含油制冷剂饱和蒸气压实验数据和利用新方程获得的计算值进行对比。发现:KT56/R22的最大偏差为0.42%,平均偏差为0.133%;3GS/R22的最大偏差为0.41%,平均偏差为0.193%。2)采用耦合油浓度的方法拟合出含纳米油制冷剂饱和蒸气压方程,并且对含油率为1%、3%、5%时含纳米油制冷剂饱和蒸气压实验数据和方程计算值进行比较,发现所有的实验值与计算值的偏差均在±0.23%以内。更多还原

【Abstract】 The function of refrigeration oil in vapor compression refrigeration system is to lubricate and pressurize the compressor. When the system runs, refrigeration oil will circulate in the system with refrigerant. It is helpful to improve the lubricating ability of friction surface in compressor and heat transfer performance of refrigerant-oil mixture by adopting appropriate nano-refrigeration-oil. As a result, energy effciency and reliability of the refrigeration system will be improved. When the refrigerant containing nano- refrigeration-oil, its thermo physics properties, such as saturated vapor pressure, will be changed. Then, the performance of refrigeration system wil be influnced. The fundamental purpose of this thesis is to analyse the variation of refrigerant after containing nano-refrigeration-oil by measuring its saturated vapor pressure; discuss the mechanism of nano-refrigeration-oil’s action on the saturated vapor pressure of refrigerant; incidence the outcome of experiment. The primary task and conclusion of this thesis list as follow:1. Conducted an investigation in preparing and properties of the nano-refrigeration-oil. After preparing nano-refrigeration-oil added with nano-NiFe₂O₄, C60 and mixed nanoparticles, we investigated their properties by means of Fourier transform infrared spectrometry method. The results were as follows:1) The compositional formulation of Tween and Span was adopted to prepare naphthenic base nano-refrigeration-oil containing nano-NiFe₂O₄, C60 or mixed nanoparticles with superior stability.2) Nanoparticle and dispersant may change some of absorption characteristic peaks of refrigeration oil. For instance, the infrared spectrum of mineral refrigeration oil 3GS would generate similar infrared characteristic peaks as 160SZ, such as aliphatic acetate esters, aliphatic ethers and primary aliphatic alcohols. These characteristic peaks’corresponding functional groups were the main factors that improve the dissolving ability between 3GS and R134a.2. Experimental study on the saturated vapor pressure of refrigerant after containing nano-refrigeration-oil. The saturated vapor pressure of refrigerant mixed with refrigeration oil and nano-refrigeration-oil were measured with different mass fractions from 1 to 9wt%, at the temperature range from 263 to 333K. The results were as follows:1) The pressure deviation of the refrigerant-oil mixture were increased as the temperature rised at the same mass fraction of refrigeration oil.2) Impaction of refrigeration oil KT56 on the saturated vapor pressure of R22 was greater than 3GS obviously at the same mass fraction of refrigeration oil. It showed that the dissolving ability of KT56 and R22 was better than 3GS and R22.3) Impaction of KT56 based nano-refrigeration-oil on the saturated vapor pressure of R22 was greater than pure KT56 obviously at the same mass fraction of refrigeration oil. It showed that the dissolving ability of KT56 based nano-refrigeration-oil and R22 was better than pure KT56 and R22.3. The experimental data of refrigerant oil mixture on saturated vapor pressure were correlated. The working achievements were as follows:1) A saturated vapor pressure equation of refrigerant-oil mixture was developed in this thesis, combining with Cavestri equation and Xiang equation. A nonlinear least square method was employed to fit parameters of the equation. The saturated vapor pressure experimental data of refrigerant oil mixture were compared with the calculated value of the new equation at different mass fractions from 1 to 5wt%. The result showed that: The maximum and mean deviation of R22-KT56 mixture is 0.42% and 0.133%, respectively; The maximum and mean deviation of R22-3GS mixture is 0.41% and 0.193% , respectively.2) A saturated vapor pressure equation of refrigerant containing nano-refrigeration -oil by means of coupling the mass fractions of nano-refrigeration-oil. The saturated vapor pressure experimental data of refrigerant and nano-oil mixture were compared with the calculated value of the new equation at different mass fractions from 1 to 5wt%. The result showed that the calculated value of the equation match all of the experimental data within the deviation of±0.23%.更多还原