R32、R22、R410A风冷空调机性能实验研究

针对R32、R22、R410A风冷单元式空调机性能进行了实验研究。研究发现,三种工质中,由于R32单位容积制冷剂制冷量最大,导致R32空调机其机组制冷量最大;同R22和R410A风冷单元式空调机相比,R32机组排气温度最高,但仍在压缩机排气温度使用极限温度之内;相同室内外空气温度下,R32和R410A空调机的冷凝压力基本相同,约为R22空调机组冷凝压力的1.6倍,但本文配置的两器铜管壁厚能够保证系统安全可靠运行;采用相同的换热器配置时,采用R32作为制冷剂的机组COP略低于R410A机组,但基本等于R22机组。     

R134a/R245fa对比R245fa高温热泵循环性能实验研究

利用螺杆式高温热泵实验台,以混合工质R134a/R245fa(质量比3∶7)和纯工质R245fa为研究对象,实验研究了两种工质在高温工况下的循环性能,并进行对比分析.结果表明,混合工质R134a/R245fa的制热量比同工况下R245fa机组高27.6%～44.3%,COP值比同工况下R245fa机组低14.3%～22.8%.当冷凝器出水温度为99.8℃时,混合工质R134a/R245fa的冷凝压力为2.12 MPa,排气温度为114.2℃,均处在机组安全范围之内.而R245fa因具有更低的冷凝压力和排气温度,可作为冷凝器更高出水温度时的热泵工质.     

R32/R1233zd(E)热泵系统的热力学分析

R1233zd(E)是一种环保、无毒、不可燃的新型制冷剂,本文将R32与R1233zd(E)混合用于替代热泵热水器传统制冷剂R22。在热泵热水器名义工况下,基于换热器中传热窄点温差的限制,对R32/R1233zd(E)二元混合制冷剂在不同质量配比下热泵循环系统的热力学特性进行计算分析。结果表明,相同工作条件下,混合工质在计算配比范围内COPh均大于R22系统,并存在两个峰值,分别对应于质量配比分别为90/10和46/54,R32/R1233zd(E)的最优质量配比为90/10。在最优配比下,系统制热系数COPh值为4.793分别比纯质制冷剂R22、R32系统的COPh增加10.2%、6.6%。新型混合制冷剂R32/R1233zd(E)很有潜力成为新的热泵替代制冷剂。     

环保工质R32替代R22理论分析和测试

通过理论热工性能分析,以及从环保及安全的角度,讨论了制冷剂R32替代R22的优势。在相同的环境下以及同一种型号的水冷柜式空调上,对使用R22、R32和R410A的空调机进行了对比实验测试,进一步认证了替代的可行性。同时指出,只要能够通过采取一系列技术措施解决R32的高排气压力、高排气温度和微燃性问题,那么R32就可以作为R22的替代制冷剂。     

新型环保制冷剂R1234ze/R600a PVTx性质

在Burnett原理基础上搭建了高精度PVT实验台,对新型环保混合制冷剂R1234ze/R600a进行了热物性测试。在温度范围为280.15~330.15 K时,测量了质量分数为80%/20%和75%/25%的R1234ze/R600a混合制冷剂的PVT性质,同时拟合出了相应温度与压力下该混合工质的密度与气体维里方程,为进一步研究该混合制冷剂作为新型替代制冷剂的性能提供了热物性参数。     

R236fa/R32混合制冷剂变浓度制冷系统的性能研究

本文对应用于变蒸发温度制冷系统的混合制冷剂R236fa/R32的饱和蒸气压力、泡露点温度、滑移温度特性进行了理论研究;建立了变蒸发温度制冷系统的计算模型;通过混合工质变组份的理论和实验研究,对机组的性能参数进行了分析;并与常规单一制冷剂制冷系统进行了性能比较。研究结果表明:大温度滑移的混合工质可实现一机变蒸发温度的特性;R236fa/R32(0.4:0.6)的COP值最高,压缩机功率最低;混合工质变蒸发温度制冷系统相对常规单一制冷剂制冷系统优点是COP值升高,压缩机功率降低,缺点是排气温度升高,但满足压缩机安全稳定运行要求。     

预冷式风冷空调机组理论与实验研究

设计了直接蒸发预冷式空调机组。对碳氢制冷剂R1270进行了实验研究,分析其在风冷空调机组中替代R22的可行性。结果表明:通过直接蒸发预冷不仅能提高机组COP,还能降低机组的排气温度。另外在相同条件下,R1270充注量为R22系统的47.1%,在额定工况下,R1270的制冷量大于R22系统,当室外环境温度升高时,R1270的制冷量略小于R22系统;二者COP值基本一致,但R1270排气温度明显低于R22。因此,从制冷能力上看,R1270作为R22的替代工质是一种较好的选择。特别是常规空调机组采用直接蒸发预冷后,在高温环境条件下,R1270的COP高于R22。     

R410A与R22在家用空调中的应用比较(1)

R410A不破坏臭氧层,是一种可以长期替代R22的绿色环保制冷剂,现已在家用空调中得到日益广泛的应用。本文分别对R410A与R22的热力性能,对4台具有可比性的R410A与R22空调的系统性能即制冷量和能效比进行比较考察,结果表明R410A具有良好的热传递与流动特性,有利于减少空调换热器尺寸、提高系统运行效率。     

热泵热水器中R1234ze(E)/R32替代R22的可行性分析

本文分析了R1234ze(E)/R32混合工质的环保及安全特性、溶油性、温度滑移和饱和蒸气压力特性,对不同配比R1234ze(E)/R32混合工质在热泵热水器系统中的循环性能进行了理论分析,并与R22进行比较。结果表明:R1234ze(E)/R32混合制冷剂对环境影响较小,可燃性低,具有与R22相似的饱和蒸气压力曲线;可在较大配比范围实现对R22的替代,且存在最优质量配比(45/55),对应的COP_h达到4.744,较R22系统提高了8.81%,单位质量制热量和单位容积制热量分别增加了3.59%和27.59%,压比和排气温度均减小,但冷凝压力略有升高。     

唐纳森新推R000020/R000021两款空滤产品

唐纳森中国售后市场于2009年2月推出R000020／R000021两款空滤产品。秉承唐纳森产品一贯的高品质与高标准,这两款新品专门应用于北重TR50、3307B、3307D等车型。这两款新品均采用受专利权保护的独特过滤材料,     

Performance of a new refrigeration cycle using refrigerant mixture R32/R134a for residential air-conditioner applications

In this paper, a new refrigeration cycle (NRC) using the binary non-azeotropic refrigerant mixture R32/R134a is presented, which can be an alternative refrigeration cycle applied in residential air-conditioner. In the NRC, refrigerant circuit of the evaporator is separated into two branches. Because the non-azeotropic mixture has the characteristic of temperature glide, an important benefit of such configuration is that the Lorentz cycle can be realized. Compared with that of conventional cycle configuration, the new cycle efficiency can be improved. The calculating results show that, in the conventional refrigeration cycle (CRC), the mixture R32/R134a has a close performance to that is obtainable with pure refrigerant R22. However, the mixture R32/R134a in the NRC will result in a better performance. The maximal COP can be improved in a range of 8–9% over that of the CRC, and the volumetric refrigerating capacity can be approximately increased by 9.5%.     

A thermodynamic analysis of a transcritical cycle with refrigerant mixture R32/R290 for a small heat pump water heater

In this study, a thermodynamic analysis on the performance of a transcritical cycle using azeotropic refrigerant mixtures of R32/R290 with mass fraction of 70/30 has been performed. The main purpose of this study is to theoretically verify the possibility of applying the chosen refrigerant mixture in small heat pumps for high temperature water heating applications. Performance evaluation has been carried out for a simple azeotropic mixture R32/R290 transcritical cycle by varying evaporator temperature, outlet temperature of gas cooler and compressor discharge pressure. Furthermore, the effects of an internal heat exchanger on the transcritical R32/R290 cycle have been presented at different operating conditions. The results show that high heating coefficient of performance (COP_h) and volumetric heating capacity can be achieved by using this transcritical cycle. It is desirable to apply the chosen refrigerant mixture R32/R290 in small heat pump water heater for high temperature water heating applications, which may produce hot water with temperature up to 90 °C.     

Performance investigation of ozone-friendly R404A and R507 refrigerants as alternatives to R22 in a window air-conditioner

In this study, experimental research was carried out to investigate the performance of R22 and its ozone-friendly alternative refrigerants (R404A and R507) in a window air-conditioner. The performance parameters of the system using R22 were considered as benchmarks and those obtained using alternative refrigerants were compared. Experimental results showed that R22 had the lowest pressure ratio and discharge temperature closely followed by R507. The average discharge temperature obtained using R507 and R404A were 4.2% and 15.3% higher than that of R22, respectively. The lowest compressor power and energy consumption were obtained from R507 retrofitted system. Also, the highest refrigeration capacity and coefficient of performance (COP) were obtained using R507 in the system. The average refrigeration capacities of R507 and R404A were 4.7% higher and 8.4% lower than that of R22, respectively, while the average COP of R507 increased by 10.6% and that of R404A reduced by 16.0% with respect to that of R22. Generally, the investigation has revealed that R507 can be used successfully as a retrofitting refrigerant in existing window air-conditioners originally designed to use R22 in the event of HCFC phased out.     

Theoretical study of R32 to replace R410A in variable refrigerant flow systems

In recent years, global warming has reached critical levels and this has caused a gradual decrease in the use of refrigerants. In the 1997 Kyoto Conference, it was announced that after 2011, use of refrigerants which have higher global warming potential (GWP) of 150 will be restricted. Hence, it was foreseen that R410A, with a GWP of 2088, which has been used in residential heating, ventilating and air conditioning systems, will be prohibited in the near future. This study investigates the thermodynamic performance using R32, which is a potential alternative because of its low GWP, and R410A in variable refrigerant flow (VRF) systems. As a result of theoretical analysis, it was observed that the coefficient of performance of R32 is 5% higher in heating mode and 6% higher in cooling mode than that of R410A. Considering all of this, it was confirmed that R32 can be used in VRF systems as a replacement for R410A in terms of performance.     

环保型空调器的研究与试验

选择对臭氧层无破坏作用的Ｒ３２／Ｒ１３４ａ混合工质作为家用空调器工质Ｒ２２的替代物，对其与润滑油的相溶性，可燃性等进行了实验研究，并对使用这种工质的压缩机，空调器进行了实验。     

制冷剂R290及其混合物燃爆特性与安全性研究

将具有燃爆性制冷剂R290（丙烷）分别与物理抑制剂CO2和化学抑制剂R13I1（三氟碘甲烷）混合,根据混合制冷剂的热物性参数确定R290的占比。实验结果表明：R13I1与R290组成的混合工质可直接替代传统制冷剂,根据所要替代的现有制冷剂的热物性参数可确定配比。用可燃气体/蒸气爆炸试验测试装置测试R290分别与CO2和R13I1混合后的爆炸参数,实验得出CO2和R13I1环境下,二者的体积分数分别为26.5%和6.42%时,R290不再具有燃爆性。同时,针对R290,推导出化学抑制剂最小惰化浓度的预测理论公式。     

使用R407C冷媒的翅片管冷凝器的计算机模拟

本文针对R22的替代工质R407C,采用稳态分布参数法,对翅片管冷凝器进行了计算机模拟：对制冷剂整个流动方向的温度、饱和温度、干度、换热量、压力、管内换热系数进行了模拟计算并加以分析,并以回路为基本单位,比较了回路之间换热情况的差别,为系统的仿真以及使用R407C的翅片管冷凝器的设计打下基础。     

汽车空调制冷剂R134a代替R12的研究

通过对R134a与R12两种制冷剂性质的对比,分析了R134a代替R12后对空调系统产生的影响以及系统作出的相应改变,指出R134a具有作为汽车空调制冷剂应具备的各种热工性能、安全性和环境性能等条件,总结出R134a代替R12的可行性与必要性。