HCFC22替代物的理论研究及R407C气相粘度的实验研究/THEORETICAL STUDY ON ALTERNATIVE FOR HCFC22 AND EX

2018-09-14 22:23:48

potential 粘度 R407C 替代物 HCFC22



HCFC22作为一种重要的制冷剂,被广泛地应用于空调、热泵等方面。尽管其臭氧层消耗潜能ODP(Ozone Depletion Potential)值仅为0.05,但由于它对臭氧层仍有破坏作用,而且温室效应系数GWP(Global warming Potential)值为1700,因此也被列入蒙特利尔议定书修正案的禁用之列。本文的理论部分,就是探索研究适合我国国情的空调系统HCFC22的替代物。
在对前人研究工作的分析基础上,通过各种方案的对比和理论研究,筛选出一种非共沸三元替代物HFC32/HFC125/HFC152a;对其变工况循环进行计算,分析各种因素对其性能的影响;利用理论模型讨论了其安全性问题,其中包括泄漏特性和可燃性分析。理论研究表明,筛选出的新替代物是一种环境性能、热工性能、可靠性都较好的HCFC22的替代物。
在实验研究方面,对原有的振动盘式粘度计的测量原理进行了系统的分析。从转动惯量、粘性力矩等角度重新分析了悬挂系统中上、中、下悬挂柱对整个测量结果的影响,进一步讨论了相位角的问题,并重新确定了工作方程的修正项,使测量结果更为精确。在进行测量前,进行了HCFC22的校核实验,测得粘度与文献粘度相比,最大偏差不大于4.5%,验证了实验系统的可靠性。
应用振动盘式粘度计测量了混合物R407C的气相粘度。测得R407C的粘度数据32个,温度范围295K~352K,压力范围0.1MPa~2.34MPa。与文献值相比,最大偏差小于4.5%。在实验数据的基础上,回归得到了其粘度随温度和密度变化的方程。


As one kind of important refrigerant, HCFC22 has been used in air-conditioners, heat pumps, and so on. Though its ODP(Ozone Depletion Potential) is only 0.05, it will still deplete the ozone and its GWP(Global warming Potential) is 1700. So it will be phased out according to the Amendment of Montreal Protocol. The theoretical part of this paper is to investigate a better alternative of HCFC22 for the air-conditioner in our country.
Based on the development of the alternatives of HCFC22, through theoretical thermodynamic analysis and calculation, new blend refrigerant HFC32/HFC125/HFC152a is proposed. And variable working conditions, which may affect the performance of the new alternative, are also analyzed. Furthermore, its safety, including flammability and leakage, are discussed in theoretical model. All theoretical calculations show that the new alternative is one good “drop-in” replacement of HCFC22 with good thermal performance and better capability in environment and reliability.
In experimental study, serial steps are taken to promote the reliability of the oscillating disk viscometer. Careful analysis is concerned with the theory of oscillating-body viscometers, and, attention is called to the drag caused by the chuck, stem, mirror and holder. Then, oscillating phase angle is discussed in this paper. The gaseous viscosity of HCFC22 is measured to check the accuracy of the equipment. Compared with the reference, the maximum deviation of experimental result is less than 4.5%. Using this viscometer, we have mainly done the measurement of gaseous viscosity of R407C. There are 32 data from 295K to 352K and at pressure up to 2.34MPa. One equation for calculating the viscosity, dependent on temperature and density , correlates all experimental data of R407c.