用于冷冻冷藏制冷系统的新型制冷剂的理论研究

综述在冷冻冷藏系统中制冷剂替代研究的现状。在此基础上,提出一种新的混合制冷剂（HFC-161/HFC-125/HFC-143a,15/45/40）用于替代HFC-404A,该新型制冷剂的ODP为零,GWP比HFC-404A和R507A要小,其基本热力学性能与HFC-404A相近。对新型混合制冷剂和HFC-404A的循环性能进行理论分析与比较。结果表明,新型混合制冷剂的性能要比HFC-404A优越,环境性能更好,是HFC-404A潜有力的替代制冷剂。     

替代R-502及R404A的新型环保制冷剂

提出由HFC-161,HFC-125和HFC-143a组成的新型环保型混合制冷剂ZCI-9,可以替代R502用于原使用R404A的系统,且原系统可基本不作改动,其充灌量可以减少,COP值不低于原系统所充灌的R404A,同时,该混合制冷剂还具有ODP=0,GWP值小于R502和R404A的特点,将是我国拥有自主知识产权的、具有实用价值的R502较理想的长期替代物.     

HFC-161混合物替代R502的理论研究

提出一种新型制冷剂HFC-161/125/143a(质量百分比10/45/45)用于替代制冷剂R502.新制冷剂环境性能良好,ODP值为0,GWP值为3466,GWP值小于R502及其常用替代制冷剂R404A和R507.采用Refprop软件计算了HFC-161混合物的基本热物理性质,以及低温工况和变工况下的理论循环性能,并与制冷剂R502、R404A、R507的相关数据进行对比.结果表明:新制冷剂的运行压力、压比、COP值、单位容积制冷量与R502相当,温度滑移小于R502常用替代物R404A,是一种性能优良的制冷剂R502的替代物.     

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。     

替代R502的近共沸混合制冷剂R404A

R502是由HCFC-22和CFC-115组成的共沸混合制冷剂。现广泛应用于商用低温冷柜中。鉴于保护臭氧层及国际上对CFCs的禁用,R502因其中含有CFC-115而被淘汰。为此,务必寻求性能与R502相近的对臭氧层无害的新制冷工质。由HFC-125/HFC-143a及HFC134a(44/52/4 wt.％)组成的三元近共沸混合工质是R502的优先替代物。 本文对R404A的物理性质、制冷量、制冷系统和压缩机排气温度与R502进行比较,还对R404A的泄漏性和润滑油等多方面进行了讨论。     

冷水机组用HCFC-22替代工质的实验研究

HCFC-22工质的替代是国际制冷与空调行业所面临的不可避免的研究项目。本次实验对HCFC-22、HFC-134a、R407c等工质在相同工况下进行了一系列的试验,得到了在不同蒸发温度下的制冷量,输入功率及制冷系数,并验证了R407c在活塞式压缩冷水机组中替代HCFC-22的可行性。     

替代工质HCFC-22/HFC-152a汽车空调系统的特性研究

保有汽车的空调系统大多采用CFC-12制冷剂,若改用HFC-134a制冷剂系统将面临很多困难.HCFC-22/HFC-152a的混合制冷剂同原CFC-12制冷系统相容,又符合CFC替代的国际协议的规定,本文对HCFC-22/HFC-152a为制冷剂的汽车空调的性能进行了分析,并与CFC-12、HFC-134a系统进行了对比.HCFC-22/HFC-152a混合制冷剂可作为过渡替代工质,在保有的汽车空调系统中可以直接替代CFC-12.     

R417A的应用现状与展望

对比R22以及其各替代制冷剂的基本性质，介绍R417A在冷藏、冷冻、热泵冷水机组以及空调系统中与其他制冷剂的应用性能对比结果，指出R417A以其与R22相当的制冷性能、良好的润滑油适应能力是R22潜在的替代工质。     

HCFC-22替代制冷剂研究进展及其相关问题讨论

简要介绍制冷剂的发展历史,详细介绍相关行业中制冷剂的应用现状及我国目前在替代HCFC-22方面的工作,重点介绍若干最新备受关注的制冷剂如HFO-1234yf及其混合物、HFC-161及其混合物、HFC-32和R290等。由于这些制冷剂普遍存在的可燃性问题,本文也将介绍一些描述可燃性的参数以及相关的国际标准,并提出一些选择可燃制冷剂的注意点。     

R134a与R410A在空调工况下的性能比较

传统制冷剂R22的替代已是大势所趋.本文着重对R22的替代制冷剂R134a与R410A的传热、阻力压降特性进行实验比较研究,认为R410A在传热、阻力压降特性方面比R134a优良,作为R22的替代制冷剂,R410A应比R134a更有竞争力.     

Formation Conditions of Clathrates Between HFC Alternative Refrigerants and Water

There are two promising candidates as alternative refrigerants for air-conditioners and heat pumps. The first is R407C, which is composed of HFC-32 (23 mass%), HFC-125 (25 mass%), and HFC-134a (52 mass%). The second is R410A, which is composed of HFC-32 (50 mass%) and HFC-125 (50 mass%). In this study, formation conditions of clathrate compounds between water and HFC alternative refrigerants such as HFC-32, HFC-125, HFC-134a, and their mixtures, R407C and R410A, were investigated. Phase diagrams of clathrates of these HFC alternative refrigerants and their mixtures were determined. From the phase diagrams, the critical decomposition temperature and the critical decomposition pressure were determined. The relationship between the critical decomposition points for the clathrates of HFC-32, HFC-125, HFC-134a, R410A, and R407C were studied. It is found that R407C and R410A form clathrate compounds with water under the evaporating temperature condition in the refrigeration cycle of air-conditioners and heat pumps.     

Viscosity of Alternative Refrigerants R407C and R407E in the Vapor Phase from 298.15 to 423.15 K

This paper presents new measurements of the viscosity of gaseous R407C (23 mass% HFC-32, 25 mass% HFC-125, 52 mass% HFC-143a) and R407E (25 mass% HFC-32, 15 mass% HFC-125, 60 mass% HFC-143a). The measurements were carried out with an oscillating-disk viscometer of the Maxwell type at temperatures from 298.15 to 423.15 K. The densities of these two fluid mixtures were calculated with the equation-of-state model in REFPROP. The viscosity at normal pressures was analyzed with the extended law of corresponding states developed by Kestin et al., and the scaling parameters needed in the analysis were obtained from our previous studies for the viscosity of the binary mixtures consisting of HFC-32, HFC-125, and HFC-134a. The modified Enskog theory developed by Vesovic and Wakeham (V-W method) was applied to predict the viscosity for the ternary gaseous HFC mixtures under pressure. As for the calculation of pseudo-radial distribution functions in mixtures, a method based on the equation of state for hard-sphere fluid mixtures proposed by Carnahan-Starling was applied. It was found that the V-W method can predict the viscosity of R407C and R407E without any additional parameters for the ternary mixture.     

一种R410A替代制冷剂的特性及应用前景分析

目前家用空调器R22的替代制冷剂，主要是R407C和R410A。由于这些制冷剂的专利权都在国外，且价格高昂，为此，国内浙江化工研究院开发出一种可替代R410A，且部分性能优于R410A的新型环保制冷剂。受该单位委托，笔者所在公司对该制冷剂进行了实机测试分析。     

制冷剂R32的循环性能实验研究

R32由于具有环境性能优越,如ODP为零、GWP值小于R410A等优点,逐渐被认识到可以用于替代R410A。本文对R410A和R32的循环性能进行实验研究,结果表明,在不同的工况下,采用2种制冷剂时系统运行的压比基本相同,COP几乎相同。与R410A系统相比,R32系统的压缩机耗功略高,制冷量高,且排气温度高。总之,R32具有良好的热物性、环境性能及循环性能,具有极大的替代R410A的潜力。     

Thermal Conductivity of HFC-32, HFC-125, and HFC-134a in the Solid Phase

Measurements of the thermal conductivity of HFC-32, HFC-125, and HFC-134a were carried out for the first time in both solid and liquid phases at the saturation pressure at room temperature and in the temperature ranges from 120 to 263, from 140 to 213, and from 130 to 295 K, respectively. A transient hot-wire instrument using one bare platinum wire was employed for measurements, with an uncertainty of less than ±2%. The experimental results demonstrated that the thermal conductivity of HFC-32, HFC-125, and HFC-134a in the solid phase showed a positive temperature dependence. For HFC-32 and HFC-125, there were big jumps between the solid and the liquid thermal conductivity at the melting point. But for HFC-134a, the solid and liquid thermal conductivity at the melting point is almost-continuous.     

R404A在螺杆制冷机组中替代R22性能研究

在比较分析HFC非共沸混合制冷剂R404A(R125/R143a/R134a,44/52/4wt%)和R22物性特点的基础上,理论和试验研究了R404A在螺杆制冷机组中替代R22的可行性和适用性.研究结果表明,只要将原为R22设计的螺杆制冷机组稍加改动,直接加入R404A制冷剂,机组便完全能够正常运行,其各主要性能指标与R22较为接近.     

Behaviour and performances of R502 alternative working fluids in refrigerating plants

This is an experimental study that aims to evaluate both general characteristics and system performances of the most credited fluids that are likely to substitute for R502 in a refrigeration plant. R402A, R402B, R403B and R408A (still containing HCFC) and R404A, R407A and FX40 (chlorine free) have been tested. Generally, both of them have showed performances very close to those of R502 except R403B, whose COP has been found to be about 8% lower than that of R502.