混合制冷剂粘度特性研究

发布时间：2018-07-12 14:50

本文选题：混合制冷剂 + 粘度　；参考：《浙江大学》2015年硕士论文

【摘要】：制冷空调技术在过去近一百年时间里为人类提供了舒适的生活环境与必要的生产条件。然而,由于该领域在过去长期使用对臭氧层具有分解能力(ODP)的含氯卤化烃类物质作为制冷剂,使地球的臭氧层遭受了严重破坏。另一个严重的问题是传统的制冷剂具有较高的GWP(Global Warming Potential)值。目前,世界各国都在积极寻找新型替代制冷剂。混合制冷剂替代方案是制冷剂替代的研究热点之一。制冷剂的替代过程严格而谨慎,需要对与制冷剂相关的各方面进行大量而全面的测试,才能很好地评估其是否替代满足要求。粘度是制冷系统设计和优化中十分重要的物性参数。然而,文献调研发现,针对新型环保混合制冷剂粘度的实验研究十分缺乏。因此,需要对新型环保混合制冷剂的粘度特性进行实验研究,以便为制冷剂的替代提供可靠的物性数据。本文的主要工作是：针对混合制冷剂等挥发性混合物粘度测量的需要,研制了一种新的适用于测量低沸点混合物粘度的旋转式毛细管粘度计。该新型粘度测量装置在压力容器内嵌入旋转式毛细管粘度计,将旋转法升液和压力容器承压结合起来,避免了传统密封型毛细管粘度计由于抽放气的升液方式而导致混合物成分的变化,可以在很高压力下循环测量挥发性混合物溶液的粘度。采用HFC-22对旋转式毛细管粘度计进行了标定,并用HFO-1234yf对粘度计的测量精度和性能进行了评价,HFO-1234yf粘度测量值与文献值最大相对偏差为-1.62%,平均绝对偏差为1.11%。利用粘度测量装置对温度范围为278.15～333.15K的HFC-22+HFC-134a(0.7+0.3,摩尔比)的饱和液相粘度进行了实验测量,粘度测量值与文献值最大相对偏差为-1.97%,平均绝对偏差为1.33%,进一步验证了本文研制的实验装置可用于测量混合制冷剂粘度。在温度范围为278.15～278.15K,测量了HFC-134a+HFO-1234yf (0.5+0.5,摩尔比)、HFO-1234yf+HFC-152a(0.81+0.19,摩尔比)、HFC-134a+HFC-152a (0.29+0.71,摩尔比)的饱和液相粘度,采用改进型Andrade液体粘度关联式、自然对数模型、硬球模型、自由体积模型和局部浓度法,对所测得的三种混合制冷剂的饱和液相粘度实验数据进行了关联。
[Abstract]:Refrigeration and air conditioning technology has provided people with comfortable living environment and necessary production conditions in the past 100 years. However, because of the long-term use of chlorinated halogenated hydrocarbons (ODP) as refrigerants in this field, the ozone layer of the earth has been seriously damaged. Another serious problem is that traditional refrigerants have a high GWP (Global warming potential) value. At present, countries all over the world are actively looking for new alternative refrigerants. Mixed refrigerant substitution is one of the hot research topics in refrigerant substitution. The process of refrigerant substitution is strict and careful. It is necessary to conduct a large number of comprehensive tests on all aspects related to the refrigerant in order to evaluate whether the substitution meets the requirements. Viscosity is a very important physical parameter in the design and optimization of refrigeration system. However, literature investigation shows that the experimental study on the viscosity of new environmental-friendly refrigerants is very scarce. Therefore, it is necessary to study the viscosity characteristics of new environmental friendly refrigerants in order to provide reliable physical data for refrigerant substitution. The main work of this paper is to develop a new rotary capillary viscometer for measuring the viscosity of volatile mixtures such as mixed refrigerants. A rotary capillary viscometer is embedded in the pressure vessel to combine the rotary liquid lift with the pressure bearing of the pressure vessel. The traditional sealed capillary viscometer can be used to measure the viscosity of the volatile mixture under high pressure by avoiding the change of the composition of the mixture caused by the way of exhalation. The rotary capillary viscometer was calibrated with HFC-22. The measuring accuracy and performance of the viscometer were evaluated by HFO-1234yf. The maximum relative deviation between the measured value and the reference value was -1.62and the average absolute deviation was 1.11. The saturated liquid viscosity of HFC-22 HFC-134a (0.7 0.3 mole ratio) at 278.15K was measured experimentally by using a viscosity measuring apparatus. The maximum relative deviation between the viscosity measurement value and the reference value is -1.97 and the average absolute deviation is 1.33. It is further verified that the experimental device developed in this paper can be used to measure the viscosity of mixed refrigerant. The saturated liquid viscosity of HFC-134a HFO-1234yf (0.5 0.5, molar ratio) HFC-1234yf (0.81 0.19, molar ratio) / HFC-134a HFC-152a (0.290.71, molar ratio) was measured in the temperature range of 278.15K. The modified Andrade liquid viscosity correlation formula, natural logarithmic model, hard sphere model, Free volume model and local concentration method are used to correlate the experimental data of saturated liquid viscosity of three refrigerants.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB64

【参考文献】