混合制冷剂R1234yf/R32 PVTx性质的实验研究

为了获得混合制冷剂R1234yf/R32的热物性数据,本文以Burnett法为基础搭建了高精度PVTx实验台,在温度为253~313 K时,测定了质量分数为15%/85%和25%/75%混合制冷剂R1234yf/R32的PVT性质,拟合了两种不同配比的混合工质的气态维里方程,为进一步研究该工质的基础热物性提供了详实的数据。     

混合制冷剂R1234yf/R134a PVTx性质的实验研究

为了获得混合制冷剂R1234yf/R134a的热物性数据,本文利用Burnett法为基础搭建的高精度PVTx实验台,在温度为268~323 K时,测定了质量分数为55%/45%,50%/50%和45%/55%混合制冷剂R1234yf/R134a的PVT性质,最终拟合了三种不同配比的混合工质的气态维里方程,方程和实验数据具有较高的重合度。     

三元混合制冷剂R32+R161+R1234yf气液相平衡实验研究

本文研究了含R1234yf的三元混合制冷剂的气液相平衡性质和模型,利用基于液相单相循环法搭建的气液相平衡实验装置,对温度范围为283.15～323.15 K的三元混合制冷工质R32+R161+R1234yf进行了实验研究,共得到45组实验数据。同时采用Peng-Robinson-Stryjek-Vera(PRSV)状态方程结合Wong-Sandler(WS)混合法则和Non-Random Two-Liquid(NRTL)活度系数模型,在前期工作得到的二元混合工质的模型参数的基础上,对三元混合工质气液相平衡性质进行推算。最后将模型推算结果与实验数据进行对比,结果表明系统压力平均绝对偏差AAD_p为0.34%,系统组分R32和R161的气相摩尔分数平均绝对偏差AAD_y_1和AAD_y_2分别为0.002和0.001。     

R1234yf/R290/R134a系气液相平衡的模拟

本文从理论方面研究了混合制冷剂的相平衡特性,基于Peng-Robinson(PR)状态方程与Wong-Sandler(WS)混合法则,结合Predictive Soave Redlich Kwong(PSRK)方程中使用的UNIFAC基团贡献法,构建了混合物气液相平衡预测模型(PRWS-UNIFAC-PSRK)。结果表明:二元混合物R32/R1234yf的压力及气相质量分数的模拟结果与实验值偏差分别在±2.5%和±0.02内;三元混合物R134a/R1234yf/R600a的压力及气相组分质量分数计算值与实验数据的偏差基本在±3%和±0.04内;建立了R1234yf/R290/R134a系的三元相平衡图,当质量分数在0.25/0.70/0.05左右时存在共沸点。通过采用多参数状态方程,改进活度系数模型,获取更为准确的二元相互作用系数,可进一步提高模型的预测精度。     

强非共沸工质R1234yf/R170/R14系气液相平衡的模拟

超额吉布斯自由能-状态方程法(G~E-EoS)是继传统的状态方程法和活度系数法之后预测气液相平衡的一个新思路。本文采用PRWS-UNIFAC-PSRK模型对R161/R1234yf、R32/R125/R134a及强非共沸工质R1234yf/R170/R14系的气液相平衡数据进行计算。结果表明:R161/R1234yf系压力和气相组分质量分数的计算值与实验值的偏差在±1.5%和±0.02以内,优于REFPROP9.0软件的计算结果,而R32/R125/R134a系的偏差分别在±4%和±0.02以内。根据计算结果及三维相平衡图发现,R1234yf/R170/R14在质量分数比为0.4/0.2/0.4附近时体系的温度滑移现象最为明显,最大的滑移温度达到72.5 K;且R1234yf组分的质量分数越大,泡点温度与露点温度越高。     

制冷剂R1234yf替代R22的理论分析和试验研究

从热工性能、环保特性、安全性以及试验研究等角度,讨论制冷剂R1234yf替代R22的优势。试验结果表明,R1234yf在高温工况(额定制冷T3)下的能效比较R22高2%,其排气温度比R22平均降低9.8℃,R1234yf的可燃性在可燃制冷剂中是较弱的。因此,R1234yf在高温工况区替代R22具有较大的潜力。     

R32/R1234yf混合工质热泵循环性能分析

在热泵热水器的名义工况下,对R32/R1234yf混合工质热泵循环性能进行计算分析。结果表明:R32/R1234yf的最优质量配比为60/40,使制热性能系数达到最大值4.727,较R22系统增大8.64%;在最优质量配比下,R32/R1234yf系统的单位容积制热量、单位质量制热量和冷凝压力均比R22系统大,但其压比和排气温度均低于R22系统。     

R32与R1234yf可燃性对比及燃烧抑制研究

卤代烷烃和卤代烯烃等氟为代表的工质是当前使用最广泛的人工合成制冷剂，随着环保要求不断提高，可选的氟代物多具有一定可燃性。制冷剂的可燃性限制了其在家用和商用等场景下的使用范围。根据可燃工质的燃烧特性寻找阻燃方法，其中重要的手段是从研究燃烧反应机理及反应路径出发对单一或混合制冷工质进行燃烧过程反应研究。本文研究了R1234yf为代表的低碳氟代烯烃燃烧点火延迟、温度压力变化、典型组元燃烧过程；并对比了R32和R1234yf燃烧机理与反应路径。研究结果表明：R32和R1234yf与烷烃和烯烃燃烧模型吻合，R1234yf点火延迟更高，加成和夺取反应更加复杂；通过反应路径的研究发现，两种可燃性工质中间稳定产物存在较多重合，在R32中仅添加体积分数为10%R1234yf时，当量比为1时的燃烧平衡温度可下降87.5 ℃；添加体积分数5%的R32混合物的燃烧平衡温度可下降21.0 ℃，混合物可燃性可低于两者任意组分；添加少量R32后点火时间提前，放热反应的自由基生成峰值明显降低。     

R1234yf热泵技术综述与潜力分析

为了满足逐步严苛的环保法规要求,R1234yf成为车用热泵制冷剂R134a的热门替代制冷剂之一。本文对R1234yf热泵技术的研究进行了综述与分析,其GWP<1,各方面性质均符合车用热泵系统的工作需求。在传热效果上,R1234yf的沸腾传热性能略优于R134a,且冷凝过程压降比R134a低5%~10%,优于R134a系统。在诸多R1234yf和R134a系统的仿真和实验研究中,R1234yf热泵性能略低于R134a,但可以通过优化零部件、强化补气、改善工况等方式使其与R134a十分接近甚至超越。R1234yf低压饱和压力比R134a高约15%,可以适配更高的压缩机转速,低温下制热性能比R134a更好,且较低的压缩机排气温度使系统工作更为稳定,强化补气的效果也优于R134a。因此,R1234yf在车用热泵中具有较好的工作性能和发展前景,可以作为R134a的替代制冷剂。     

R1234ze(E)与R32混合工质在热泵系统中替代R410A的实验研究

新型制冷剂R1234ze(E)因较低的GWP备受制冷行业关注,其与R32的混合工质作为热泵系统制冷剂的研究也在逐步展开,本文以R1234ze(E)/R32(质量配比:27%/73%,命名为L-41b,GWP=493)混合工质为研究对象,在人工环境室中设计并搭建了空气源热泵测试系统,对比研究了L-41b与R410A在热泵系统中的性能系数COP、压缩机功耗、制热量、排气温度和循环压比。结果表明:当恒定冷凝温度,蒸发温度从5℃增加到13℃时,R410A和L-41b的COP偏差从8.6%缩小到2.8%。当恒定蒸发温度,冷凝温度从30℃提高到42℃时,L-41b的运行性能系数COP的降幅小于R410A,变工况实验表明在相对高温区L-41b替代R410A具有较好的替代性能。     

Measurement of vapor viscosity of R1234yf and its binary mixtures with R32, R125

The vapor viscosities of the new refrigerant R1234yf and its binary mixtures, R32+R1234yf, R125+R1234yf, were measured at atmospheric pressure with a falling-ball-type viscometer. The combined expanded uncertainty of the measurement apparatus was less than 1.5%. The binary mixtures consisted of 20.0, 30.0, 40.0, and 50.0 wt% R32 for R32+R1234yf and of 20.0, 35.0, 50.0, and 70.0 wt% R125 for R125+R1234yf. The viscosities of R1234yf were correlated with the Chapman–Enskog gas kinetic theory and those of binary mixtures were correlated with the Wilke mixture rule. The average absolute deviation (AAD) is 0.189% for R32+R1234yf and 1.169% for R125+R1234yf. The deviations of experimental viscosities of the binary mixtures from data calculated using RefProp v9.1 were also obtained. The AAD is 0.555% for R32+R1234yf and 1.479% for R125+R1234yf.     

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。     

Experimental investigation on heating performance of gas-injected scroll compressor using R32, R1234yf and their 20wt%/80wt% mixture under low ambient temperature

In this paper, an integrated gas-injected scroll compressor heat pump system using R1234yf, R32 and its binary mixtures as working fluid was developed and their heating performances under low ambient temperature were quantitatively evaluated. A composite test system consisting of second-refrigerant calorimeter and water-cooled condenser was used to test the system working performance. The condensing temperature, evaporating temperature, compressor power input and other variables were analyzed to evaluate the system heating capability and energy efficiency. Test results showed that the R1234yf system can run at an evaporating temperature of −25 °C. R1234yf/R32 mixture can run at an evaporating temperature of −20 °C and it has the highest heating COP value among other refrigerants; R1234yf/R32 gas injection system provided very significant performance improvements for heating performance, compared with no gas injection, the heating capacity and heating COP can improve 16%~20% and 13%~16%, respectively.     

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。     

Isothermal vapor liquid equilibrium measurements for difluoromethane (R32) + fluoroethane (R161) + trans-1,3,3,3-tetrafluoropropene (R1234ze(E)) ternary mixtures

Difluoromethane (R32) + fluoroethane (R161) + trans-1,3,3,3-tetrafluoropropene (R1234ze(E)) ternary system could be a promising alternative refrigerant mixture. The vapor liquid equilibrium (VLE) data for this system are important for the evaluation of its performance. In this work, the VLE of R32 + R161 + R1234ze(E) were measured for the first time by a quasi-static analytical apparatus over the temperature range of 283.15 to 323.15 K. The ternary system of R32 + R161 + R1234ze(E) is a zeotropic system within the studied temperature range. The Peng–Robinson–Stryjek–Vera (PRSV) equation of state combined with the Wong–Sandler (WS) mixing rule and the non-random two-liquid (NRTL) activity coefficient model was used to predict the ternary VLE data by using the parameters of binary mixtures (R32 + R161, R32 + R1234ze(E) and R161 + R1234ze(E)). The calculated values show excellent agreement with the experimental results. The average absolute deviation (AAD) of pressure is 0.16%. The average absolute deviations of vapor phase mole fractions for R32 and R161 are 0.0021 and 0.0028, respectively.