第四代制冷剂HFO-1234yf

介绍了2,3,3,3-四氟丙烯(HFO-1234yf)的各种性能、用途以及合成研究进展,HFO-1234yf作为1,1,1,2-四氟乙烷(HFC-134a)的替代品而被应用于移动空调系统,已成为第四代制冷剂。     

新型制冷剂HFO-1234yf

HFO-1234yf作为HFC-134a的替代物,已基本得到了欧洲主要汽车厂家的认可。本文介绍了HFO-1234yf的物理性能、制冷效率、可燃性、互溶性、材料相溶性、用途以及合成研究进展。     

HFO-1234ze与HFC-32混合制冷剂用于热泵热水器的实验研究

本文选用了NIST发行的REFPRO9.0制冷剂计算程序及KW2模型参数对混合制冷剂HFO-1234ze与HFC-32在不同配比下的热物性进行了模拟计算,并依据热泵热水器测试的标准工况,计算了不同配比下混合制冷剂的理论循环特性,分析得出了HFO-1234ze/HFC-32较为合适的配比。通过一次加热(即热式)热泵热水器实验台,对多种环境工况及不同进水温度进行性能测试,分别对R410A和混合制冷剂(HFO-1234ze与HFC-32配比0.3/0.7)在实验系统中的压缩机功率、系统性能系数、压缩机吸、排气压力和温度、冷凝器出水温度等参数进行了对比分析。结果表明:混合制冷剂(HFO-1234ze与HFC-32配比0.3/0.7)的压缩机功率和排气压力都低于R410A系统,而COP高于R410A系统,在标准工况下,分别为4.03和3.56,且在高于标准工况的环境温度情况下,混合制冷剂系统COP下降速率低于R410A系统,有利于热水器机组的安全稳定运行,在替代R410A系统方面具有可行性。     

HFO-1234yf——新一代汽车空调制冷剂

介绍一种新型的应用于汽车空调系统的制冷剂HFO-1234yf。该制冷剂的典型特点是具有很低的全球变暖潜值（GWP=4）,且对于使用R134a制冷剂的汽车空调系统是一种潜在的且经济的直接替代方案。汽车空凋台架测试和实车性能试验的结果表明,直接充注HFO-1234yf制冷剂后,系统制冷量和COP与原R134a系统偏差均在5％左右。关于材料相容性方面,均可以直接使用POE和PAG润滑油,与橡胶的兼容性及软管密封性方面未见不良反应。危险性试验评估结果显示,该制冷剂为低毒性,且毒性低于R134a;实车泄漏试验测试表明,制冷剂泄漏时,遇到明火不会导致燃烧加剧。     

新型制冷剂R1234ze(E)及其混合工质研究进展

低GWP值制冷剂R1234ze(E)(trans-1,3,3,3-tetrafluoropropene)作为R134a较为理想的替代品而被关注,但其单一成分的热力学性能和传输特性并不理想,在R1234ze(E)中混入R32成分可以有效改善其热力学性能。本文概述了低GWP值工质R1234ze(E)及其与R32混合物的热物性特征、传输特性及系统运行性能方面的研究现状,并与目前常用的制冷工质进行比较分析,指出R1234ze(E)与R32混合工质有望成为新型低GWP值替代工质。     

制冷剂发展历程

主要叙述制冷剂随着制冷技术的发展而变迁的过程,从初期的能用即可和安全与耐久性等要求,演变为保护大气臭氧层免遭破坏和防止全球气候变暖等更加严格的要求。指出天然制冷剂可能是制冷技术发展的终极。     

一种在汽车空调系统中使用的新制冷剂—HFO-1234yf

本文综述了HFO-1234yf制冷剂的热力性能、燃烧性、毒性和使用性能,分析了它在汽车空调系统中使用的评价。     

HFO-1234yf汽车空调用新制冷剂即将问世

代表空调制冷行业最新先进水平的开利公司新产品10500kW常青树（Evergreen）19XRD双压缩机离心冷水机组是该公司在上海生产的单机容量最大的采用环保工质HFC134a的离心冷水机组。它是开利公司在上海的全球研发中心为大型机场、超市、商厦、工厂和区域供冷等开发和研制的，将面向全球市场。该机组包含着开利公司多项高效率的专利技术，它已被中国标准认证中心定为节能产品。     

新一代制冷剂HFO-1234yf的热物性模型

基于Peng-Robinson通用状态方程,采用基团贡献原理以及多项式拟合方法,建立了符合精度要求的新型LGWP制冷剂HFO-1234yf的热物性模型,并对模型进行了验证,利用数学软件对模型进行编程求解,得到了较为全面的HFO-1234yf制冷剂的热物性数据。将HFO-1234yf制冷剂与R134a及R417A制冷剂的热物性能进行了对比,结果显示HFO-1234yf的饱和蒸汽压力与定压比热容和R134a的表现相似,二者的饱和蒸气压均低于R417A,HFO-1234yf制冷剂与R134a和R417A相比,其饱和状态焓值较低,这将导致HFO-1234y系统运行时的性能系数不高。该模型能为HFO-1234yf制冷剂在汽车空调以及固定式空调制冷设备上的应用提供理论依据。     

日本新一代氢氟醚制冷剂的研究

本文介绍了日本政府组织的有关“新-代氢氟醚制冷剂研究开发”国家项目的进展和成果，HFE-245mc和HFE-143m最终被分别认为有望成为高温热泵工质CFC-114和冰箱、汽车空调工质CFC-12、HFC-134a的替代物。但迄今尚未找到替代HCFC-22的氢氟醚物质。原拟用于替代CFC-ll和HCFC-123的HFE-347mmy和HFE-347mcc，由于其制冷性能较差，最终也已基本被排除。     

HFO-1234ze在空气源热泵热水器中 替代R417A、R22的研究

首先从热物性、ODP、GWP、工质毒性、可燃性方面对HFO-1234ze、R417A、R22三种制冷剂进行对比,并进行理论计算,初步分析HFO-1234ze制冷剂运用在空气源热泵热水器上的可行性。然后,在焓差法实验室内,对分别采用HFO-1234ze,R417A和R22作为制冷工质的空气源热泵热水器进行名义工况下的性能测试,对三种制冷剂的吸排气温度,吸排气压力,压缩机输入功率、制热量、性能系数进行对比分析。本文研究结果显示HFO-1234ze可以作为R417a与R22在热泵热水器中的替代制冷剂。此次研究为热泵热水器的工质选择提供参考。     

The fluorinated olefin R-1234ze(Z) as a high-temperature heat pumping refrigerant

Estimates are provided for R-1234ze(Z) of its: (1) critical temperature, pressure, and density, acentric factor, and ideal gas specific heat at constant pressure, and (2) various thermodynamic and transport properties, which are used to predict the performance potential of R-1234ze(Z) in high-temperature heat pumping applications. In particular, for an idealized cycle, the coefficient of performance and volumetric heating capacity for R-114 are 3.24 and 1667 kW m⁻³, respectively, and for R-1234ze(Z) are 3.40 and 1645 kW m⁻³, respectively. The attractiveness of R-1234ze(Z) is confirmed further through heat exchanger simulations. This paper demonstrates that R-1234ze(Z) deserves further consideration as a possible R-114 replacement.     

Second law analysis of an automotive air conditioning system using HFO-1234yf,an environmentally friendly refrigerant

In this paper, a comparative study of the second law of thermodynamics is presented to determine the possibility of using HFO-1234yf, an environmentally friendly refrigerant, as a drop-in replacement of HFC-134a in automotive air conditioning system. For the thermodynamic analysis, a computer program is written to simulate the operating conditions of automobile air conditioning system. The thermodynamic properties of the refrigerants are extracted from the REFPROP 8.0 software. For calculating the coefficient of performance (COP), exergy destruction, exergy efficiency and entropy generation, computational models are used to evaluate the effects of different parameters on their changes. It is found that using HFO-1234yf as the air conditioning refrigerant leads to higher exergy efficiency compared to HFC-134a. Also, maximum entropy generation and exergy destruction occur in the compressor. The exergy destruction and entropy generation of the cycle components are less in the case of using HFO-1234yf refrigerant instead of HFC-134a.     

Mechanism of thermal decomposition of HFO-1234yf by DFT study

Twenty-two chemical reaction pathways of thermal decomposition of 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf, CF₃CFCH₂) are proposed to investigate the formation mechanism of some possible products (CF₃H, CF₄, HF, H₂) by using density function theory (DFT) simulations with M06-2X/6–311++(d,p) level of theory. The results point out that the ground state CF₃CFCH₂ will excite into the lowest triplet state CF₃CF-CH₂ favorably in the first step with an energy barrier of 264.67 kJ mol⁻¹ and pathway 5 is the most preferred route of homolytic cleavage reactions with the lowest energy barrier of 205.70 kJ mol^-1. F radical is hard to generate during thermal decomposition processes because of its higher energy barrier. H radical and CF₃ radical play a dominant role in thermal decomposition of HFO-1234yf. H-abstraction and F-abstraction reactions are proposed in subsequent radical attacking chain reactions. CF₃H and H₂ are easier to be generated due to their lower energy barriers. Our work presents the mechanism of thermal decomposition of HFO-1234yf from the molecule level and provides a reference for studying the thermal stability of other working fluids.