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.     

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。     

HFC-161及其应用

介绍ODs替代品HFC-161的性质及应用实例，通过分析与实验说明这些混合制冷剂能够分别替代R410A，R407C，R404A和HFC-134a，均具有环保性能优异、能效比高、用量少、与原系统兼容等特点。     

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。     

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。     

低温装置用R502替代工质的性能分析

本文对替代低温装置制冷剂R502的混合工质(如R404a、R507、R407a、R407b、R407c)进行了热力计算和循环分析,结果表明R407a、R407b、R407c可作为R502的替代工质,且比R404a和R507具有明显的节能效果。     

R404A制冷剂在商用制冷设备中的应用分析

R404A制冷剂是由R125、R143a和R134a组成的近共沸制冷剂，它主要应用在温度为-20～-50℃的商用制冷设备中，是替代R502的首选制冷剂。但目前它在商用制冷中还没有得到广泛应用。本文首先简要介绍了R404A制冷剂的组成及其性质，然后分析了它在当前市场中的应用情况，结合R404A发展的驱动力分析，指出了R404A在未来有着广阔的市场前景。     

R404A在涡旋式冷凝机组中替代R22的试验研究

在理论分析R404A和R22物性的基础上,对R404A在高温涡旋式冷凝机组中替代R22进行试验研究。研究结果表明,适用R22的机组更换高压压力开关、压缩机冷冻油、干燥过滤器和视液镜、热敏继电器后,充注R404A制冷剂,机组能够正常运转。同时发现蒸发温度和环境温度对R404A机组的制冷量、COP的影响比对R22的影响更大,对输入功率、电流、排气温度和排气压力的影响与对R22的影响相对接近;相同结构配置机组,R404A制冷剂的充注量比R22的大,制冷剂充注量的增加与理论质量流量增加的比例不同。     

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.     

R404A在螺杆乙二醇机组中替代R22性能试验研究

为研究HFC非共沸混合制冷剂R404A (R125/R143a/R134a,44/52/4wt%)替代R22的可行性和适用性,将原为R22设计的YCLG16开启式螺杆乙二醇机组稍加改动,充入R404A制冷剂,在不同工况下进行性能试验.试验结果表明,与R22螺杆乙二醇机组相比,R404A的工作压力、制冷量、消耗功率分别增加20%、2%～6%和12%～15%,排气温度和COP则分别下降8%～19%和10%.     

Viscosity of refrigerants R12, R113, and R114 and mixtures of R12 + R114 at high pressure

New viscosity measurements for the gaseous and supercritical state of the halogenated hydrocarbons R12, R113, and R114 and binary mixtures of R12 + R114 of different compositions are presented. The measurements were carried out at superheated and supercritical temperatures from 30 to 200° C and in the pressure range from 1 to 80 bar. Viscosity was measured with an oscillating-disk viscometer and the data obtained are relative to the viscosity of nitrogen. The estimated accuracy of the measured results is ±0.6%. The results obtained show that, at subcritical temperatures, the pressure effect on viscosity is negative. This anomalous behaviour is investigated in detail in this work. At atmospheric pressure the viscosity of gas mixtures is almost a linear function of their composition. At high pressure, the residual viscosities - ₀ of both the pure components and the mixtures were used to follow a single relationship versus the residual reduced density _r0.Paper presented at the Tenth Symposium on Thermophysical Properties, June 20–23, 1988, Gaithersburg, Maryland, U.S.A.     

R32/R134a和R407C用于变浓度热泵系统的实验

为了解决R32/R134a应用于变浓度热泵系统存在的排气温度过高问题,提出使用三元混合工质R407C用于该系统中.以R32/R134a和R407C作为工质在变浓度容量调节热泵系统中进行了吸气压力不变时的变浓度实验.实验结果表明,R407C在本系统中变浓度范围低于R32/R134a,但R407C的排气温度和耗功均低于R32/R134a,具有良好的变浓度调节潜力.     

Viscosity of Gaseous R404A, R407C, R410A, and R507

This paper presents new measurements of the viscosity of gaseous R404A (52 wt% R143a, 44 wt% R125, 4 wt% R134a), R407C (23 wt% R32, 25 wt% R125, 52 wt% R143a), R410A (50 wt% R32, 50 wt% R125), and R507 (50 wt% R143a, 50 wt% R125). These mixtures are recommended as substitutes for the refrigerants R22, R502, and R13B1. Measurements were carried out in an oscillating-disk viscometer. The obtained values of the viscosity are relative to the viscosity of nitrogen. The experiments were performed at atmospheric pressure over the temperature range 297 to 403 K. and near the saturation line up to pressures of 0.6 P _crit. The estimated uncertainty of the reported viscosities are ±0.5% for the viscosities at atmospheric pressure and ± 1% along the saturation line, being limited by the accuracy of the available vapor pressure and density data. The experimental viscosities at atmospheric pressure are employed to determine the intermolecular potential parameters, and , which provide the optimum representation of the data with the aid of the extended law of corresponding states developed by Kestin et al. A comparison of the experimental viscosity data with the values calculated by REFPROP, both at atmospheric pressure and along the saturation line, is presented.     

R32替代R22的可行性探讨

从理论热工性能分析、环保、安全以及性能测试试验对比等角度,讨论制冷剂 R32 替代 R22 的优势,认为R32替代R22是可行的.同时,分析R32替代R22时存在的高排气压力和高排气温度以及安全性问题.基于目前的制冷技术以及R32本身的热力特性,只要能够通过采取一系列技术手段和安全措施解决这些问题,R32可以作为R22良好的过渡或替代制冷剂.     

R290与R404A在水平管内沸腾换热的压降研究

将R22的两种新型替代工质R290和R404A在光管和内螺纹管中的沸腾换热压降实验结果与Lockhart ＆ Martinelli压降计算关联式预测结果进行了比较,并依据工质R290和R404A在内螺纹管中的实验压降值对Lockhart ＆ Marlinelli压降计算关联式进行了修正。结果表明Lockhart ＆ Martinelli关联式对R404A在光管和内螺纹管的沸腾换热摩擦压降,均有良好的预测精度,平均偏差分别为-11．52％和-17．86％。Lockhart ＆ Martinelli关联式可以较好的预测R290在光管内的沸腾换热摩擦压降,平均偏差为-21．68％;经修正后的Lockhart ＆ Martinelli关联式可以较好的预测R290在在内螺纹管中的沸腾换热摩擦压降,Lockhart ＆ Martinelli关联式乘上修正系数2．06后的修正值与实验值偏差较小,平均偏差为2．37％。研究结果对R290和R404A蒸发器的工程设计及优化具有一定参考意义。     

Viscosity of R134a, R32, And R125 at Saturation

This paper reports the results of the measurement of the viscosity of R134a close to the saturation line in the vapor phase. The new measurements were carried out in a vibrating-wire viscometer specially constructed for the purpose, and the results have an accuracy of ±2%. In addition, the opportunity is taken to present a reevaluation of earlier measurements along the saturation line of the viscosity of R32 and R125. Improved equations of state for these fluids are now available and can be employed to generate improved values for the viscosity.     

冷藏车层叠式蒸发器应用R404A与R22和R134a的比较

采用分布参数法对层叠式蒸发器建立数学模型，并对蒸发器采用R404A，R22和R134a时的换热和流动性能进行模拟比较。结果表明，在空调工况范围内，新型中低温混合制冷剂R404A具有R134a换热性能好和R22压降小的特点，能够很好地适用于冷藏车系统空调侧层叠式蒸发器。     

新型混合制冷剂R1270/R152a/R13I1的理论研究

针对制冷剂R22的替代问题,提出了一种适用于空调等制冷设备的环保型混合制冷剂R1270/R152a/R13I1。基于Refprop8.0,对R1270/R152a/R13I1的基本热物理性质和制冷系统循环性能进行了分析,研究表明:在标准工况下,R1270/R152a/R13I1混合制冷剂的COP和单位容积制冷量均与R22相当,非常有利于直接灌注式替代;在变工况下,R1270/R152a/R13I1的滑移温度较小,性能优于R407C,单位容积制冷量与R407C和R22相当,是一种优良的R22替代物。     

在家用／商用空调中用R32替代R22的探索

在R22的替代工作进入实质性阶段,但国内外成熟替代品又尚不明朗之际,本文在分析国内外R22替代物的现状、存在的问题以及国际上对环保工质要求的新趋向的前提下,探索提出在家用／商用空凋中使用R32替代R22的设想,并从其热物理性质、环保特性、安全性、热工性能、市场可获得性等几个方面,与现有的R22替代物R410A,R290和R1234yf等进行比较,认为R32是一种兼顾减排、安全、节能和市场诸方面要求的、很有前景的R22替代制冷剂。     

Measurements of the thermal conductivity of liquid R32, R124, R125, and R141b

This paper reports measurements of the thermal conductivity of refrigerants R32, R124, R125, and R141b in the liquid phase. The measurements, covering a temperature range from 253 to 334 K and pressure up to 20 MPa, have been performed in a transient hotwire instrument employing two anodized tantalum wires. The uncertainty of the present thermal-conductivity data is estimated to be ±0.5%. The experimental data have been represented by polynomial functions of temperature and pressure for the purposes of interpolation. A comparison with other recent measurements is also included.