McLinden Mark O, Huber Marcia L
Applied Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, Colorado 80305, United States.
J Chem Eng Data. 2020;65(9). doi: 10.1021/acs.jced.0c00338.
As we enter the "fourth generation" of refrigerants, we consider the evolution of refrigerant molecules, the ever-changing constraints and regulations that have driven the need to consider new molecules, and the advancements in the tools and property models used to identify new molecules and design equipment using them. These separate aspects are intimately intertwined and have been in more-or-less continuous development since the earliest days of mechanical refrigeration, even if sometimes out-of-sight of the mainstream refrigeration industry. We highlight three separate, comprehensive searches for new refrigerants-in the 1920s, the 1980s, and the 2010s-that sometimes identified new molecules, but more often, validated alternatives already under consideration. A recurrent theme is that there is little that is truly new. Most of the "new" refrigerants, from R-12 in the 1930s to R-1234yf in the early 2000s, were reported in the chemical literature decades before they were considered as refrigerants. The search for new refrigerants continued through the 1990s even as the hydrofluorocarbons (HFCs) were becoming the dominant refrigerants in commercial use. This included a return to several long-known natural refrigerants. Finally, we review the evolution of the NIST REFPROP database for the calculation of refrigerant properties.
随着我们进入“第四代”制冷剂时代，我们来考量制冷剂分子的演变、促使人们需要考虑新分子的不断变化的限制因素和法规，以及用于识别新分子并使用它们设计设备的工具和物性模型的进展。这些不同的方面紧密相连，自机械制冷早期以来就或多或少地持续发展，即便有时处于主流制冷行业的视野之外。我们着重介绍了对新制冷剂进行的三次独立而全面的探索——分别在20世纪20年代、80年代和21世纪10年代——这些探索有时发现了新分子，但更多时候是验证了当时正在考虑的替代物。一个反复出现的主题是，真正新颖的东西很少。大多数“新”制冷剂，从20世纪30年代的R - 12到21世纪初的R - 1234yf，在被视为制冷剂之前几十年就已在化学文献中有所报道。即便氢氟烃（HFCs）在商业应用中逐渐成为主导制冷剂，对新制冷剂的探索在20世纪90年代仍在继续。这包括重新启用几种早已为人所知的天然制冷剂。最后，我们回顾了美国国家标准与技术研究院（NIST）用于计算制冷剂物性的REFPROP数据库的演变。
