CO_2低温冷冻冷藏系统的节能分析

二氧化碳既可以作为制冷剂,也可以作为载冷剂应用于低温冷冻冷藏工程,这对解决制冷剂替代问题和节能减排都很有意义。本文比较常规载冷剂系统、二氧化碳载冷剂系统和二氧化碳/氨复叠制冷系统的特点和运行能耗。结果表明,二氧化碳制冷剂和载冷剂系统具有制冷机组性能系数高、循环泵耗功小、管路和设备保温散热少及空气冷却器霜层较薄等特点。     

专利技术

摘要：本发明公开了一种用于汽车空调的碳氢混合制冷剂,由丙烯、二甲醚以及五氟丙烷混合组成,各组分质量百分比为：丙烯10％～20％;二甲醚60％～80％;五氟丙烷10％～20％。同时公开了其制备方法。作为替代R134a的碳氢混合制冷剂,本发明制冷剂不破坏臭氧层,温室效应潜能也较低、低毒、节能、制冷性能佳、用量小、与原有R134a制冷润滑油有很好的相容性,对于汽车空调,无需改动原有设备,可实现灌注式替代R134a。同时,其制备工艺简单,成本低。     

制冷压缩机的润滑油选用分析

文章简述了制冷系统中润滑油的作用和一般理化性能要求,阐明制冷剂系统中各设备对润滑油的特殊要求;并分析了冷冻油对制冷系统制冷性能的影响.列举常用制冷剂所用的冷冻油,分析不同种类的冷冻油对制冷剂的适应性,并指出,选用冷冻油要根据其制冷压缩机的类型、工况和制冷剂的种类来综合考虑,并且需要通过压缩机相应的性能测试来判定选用的合理性.     

低GWP替代制冷剂R452B和R513A研究

本文列举了制冷及热泵系统市场主流制冷剂R410A和R134a及其低GWP环保替代制冷剂R452B和R513A的特性参数。并基于压缩机测试结果,对比分析了主流制冷剂及其替代制冷剂在压缩机设计不变更前提下质量流量、制冷量、功率及制冷效率这些主要参数的变化趋势。最后得出结论:R452B和R513A作为替代R410A和R134a的低GWP制冷剂,在压缩机及系统不变更或少变更的情况下,可以满足客户的需求。     

碳氢化合物在冷冻箱系统中的试验研究

通过对同一台冷冻箱的不同制冷剂循环系统的反复测试,从制冷循环的多个参量分析中给出了替代制冷剂R600a/R290的实际循环效果,非共沸混合制冷剂作为中小型制冷装置中的直接替代物,能够满足原系统的温度、压力要求,其充注量仅为R12的35%～40%.     

合成类HCFCs替代制冷剂的研究进展

制冷空调领域内使用量最大的HCFCs制冷剂目前正处于加速淘汰的阶段,替代品、替代技术路线的选择至关重要.本文介绍R32,R1234yf(R1234ze),ZCI系列和DYR系列等新型合成类替代制冷剂的最新研究进展,从基本热物性、传热特性、理论循环、机组性能等多个角度与最主要的HCFCs制冷剂R22进行对比,并分析部分替代品的应用前景,为我国制冷空凋行业制冷剂替代工作提供参考.     

制冷空调行业HCFCs工质替代的分析

立足HCFCs制冷剂替代的进程,分析对大气臭氧层破坏和温室效应,得出HCFCs作为制冷剂淘汰的必要性和进程;分析发达国家和发展中国家不同经济技术水平,提出《蒙特利尔议定书》淘汰HCFCs制冷剂的时间表,结合我国制冷空调行业的实际情况,提出相应的淘汰进程;提出HCFCs制冷剂工质替代既要开发新工质也要从制冷设备入手减少充注量和控制设备泄漏的新路线。     

商用制冷设备在用制冷剂现状及未来趋势

随着生活水平的提高,制冷技术带给人们舒适的生活条件,但它也给人们造成一些负面影响。在环境问题尤其是臭氧层破坏和温室效应问题日益加剧的形势下,制冷剂的发展及替代越来越受到世界各国的关注。本文介绍了制冷剂发展历程及世界各国商用制冷设备常用制冷剂的现状,以此为基础,总结了制冷剂未来发展趋势。     

全封闭制冷设备的制冷剂回收研究

可用物理方法方便、干净地回收全封密制冷设备的制冷剂。本文介绍了该技术原理、装置和回收效果，分析了回收过程，找到了保证安全和回收的制冷剂质量等的条件和途径，回收的制冷剂可再使用。分析表明本文方法同样适用于回收新型无氟制冷剂、适用于非封闭式制冷设备。这种技术为长期沿用的极不合理、造成严重污染的“人工排放”制冷剂的维修工艺提供了一个良好的替代手段。     

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。     

Analysis of alternatives to high GWP refrigerants for eutectic refrigerating systems

The EU Regulation No 517/2014 is going to phase-out R507A and R404A refrigerants because of their high GWP values. Different alternative refrigerants are under consideration, with the research results available for various applications. However, the eutectic refrigerating system operates at specific conditions, which are analysed in the paper. The applicability of the alternative refrigerants in the eutectic systems is analysed, focusing on performance and availability of components.The analysed alternatives are hydrocarbons, CO₂ and HFC/HFO mixtures. The hydrocarbons would be a good alternative, but the required system components are not available. The HFC/HFO mixtures are the alternative with the available system components. The drop-in replacement test results with R448A refrigerant demonstrate significant performance degradation. At 25 °C ambient temperature the pull-down time increased by 24% and the power consumption increased by 9%. Also, due to the glide and lower evaporation pressure, the retrofitted system cannot reach the required evaporation temperatures.     

R32和R410A循环特性对比研究

国内外加速淘汰 HCFCs 制冷剂的时间表已经确定,而理想的替代制冷剂仍不明确.本文以风冷式冷(热)水机组为对象,对目前业内应用较多的替代制冷剂 R410A 以及被国内学者关注的制冷剂 R32 的循环特性进行理论分析及实验研究,并指出应用 R32 制冷剂时存在的问题,以期为国内 R22 的替代决策提供有益的参考.     

A cost-based method for comparing alternative refrigerants applied to R-22 systems: Remplacement du R22: méthode de comparaison des frigorigènes candidats

This paper describes the development and application of a general purpose method for comparing alternative refrigerants. The method utilizes a single performance index based upon minimum cost for a simplified system operating with a given cooling capacity and efficiency. The cost-based method is an improvement over other methods for evaluating refrigerants in that it more appropriately considers the influence of both thermodynamic and transport properties on refrigerant choice and it allows consideration of additional costs associated with some replacements (e.g. safety features for flammable refrigerants). A computer model based upon this method was used to evaluate the performance of several leading R-22 replacement candidates for window air conditioners. Primarily, the cost differences between alternative refrigerants are associated with the heat exchangers and the refrigerant/oil requirements. The cost differences associated with different compressor displacement requirements were found to have a minor influence on overall cost differences. For the optimized systems, all of the alternatives had system costs that were within about 4% of those for R-22. Further, the differences between most of the alternative refrigerants were smaller than the uncertainties in the analysis.     

Screening of pure fluids as alternative refrigerants

Hydrofluorocarbons are now well established as refrigerants because of their zero ozone depletion potential. Since they have a high global warming potential, other alternatives as, e.g. fluorinated ethers or cyclic hydrocarbons are considered as next-generation refrigerants. Screening of alternative refrigerants is difficult because mostly no or only few data are available. To evaluate, e.g. the cycle performance, the thermodynamic properties of the refrigerants must be known and described accurately by an equation of state. Here, the physically based BACKONE equations are used to describe alternative refrigerants, such as natural refrigerants, hydrofluorocarbons, fluorinated cyclic hydrocarbons, and fluorinated ethers. BACKONE needs only a few substance specific parameters to describe thermodynamic properties with high accuracy. Thus, even alternative refrigerants, with very few available experimental data can be described. Calculations with BACKONE of the performance of many refrigerants show that some hydrocarbons and fluorinated ethers are a good alternative.     

替代制冷剂的研究与应用现状

本文介绍了替代制冷剂在电冰箱、空调器和汽车空调的研究与应用的现状，并针对替代制冷剂的特点对其应用趋势进行了讨论。     

采用替代工质的风冷热泵机组性能试验研究

近年来，我国风冷热泵空调技术的应用方兴未艾，风冷热泵由于其自身的优点，得到了制冷行业的重视。本文以搬2、R134a、R407C及R404A为工质，运用试验研究的方法，对热泵系统在冬季标准工况下的制热量及耗功进行测试和比较，可为风冷热泵系统中替代工质的选用，提供详细的实测数据和具体的设计准则。     

Trade-offs in refrigerant selections: past, present, and future

Recent attention to depletion of stratospheric ozone, by chemicals containing bromine and chlorine, resulted in an international accord to halt their production. The most widely used refrigerants are among them. Chemical and equipment manufacturers mounted aggressive research and development programs to introduce alternative and transition refrigerants, associated lubricants and desiccants, and redesigned equipment. The already difficult criteria became even more complex, with subsequent linkage of chemical emissions from human activities to global climate change. The very successful response to protect the ozone layer has led some regulators and users to assume that ideal substitutes will be found. Such chemicals should be free of all environmental and safety concerns, be chemically and thermally stable, and perform efficiently. The analyses presented in this paper demonstrate that the outlook for discovery or synthesis of ideal refrigerants is extremely unlikely. Trade-offs among desired objectives, therefore, are necessary to achieve balanced solutions. The paper also shows that fragmented regulation of the chemicals involved, to address individual issues, jeopardizes the prospect of solving subsequently addressed problems. The paper reviews the history of refrigerants, their roles in ozone depletion and global climate change, and necessary trade-offs in refrigerant selections.     

碳氢化合物用于小型制冷装置的研究现状

碳氢化合物（HCs）作为氯氟烃类（CFCs）、氢氯氟烃类（HCFCs）的替代制冷剂,以其优良的环保和热力性能,被广泛应用于各种小型制冷系统如房间空调器、电冰箱等。本文介绍国内外碳氢化合物制冷剂在小型制冷装置上的研究进展及应用现状。另外,针对碳氢化合物在实际工程应用中的安全隐患问题,对其与制冷系统材料的兼容性、与润滑油的相溶性以及可燃性问题进行重点阐述,并展望碳氢化合物制冷装置的技术发展趋势和市场前景。     

基于双级离心式冷水机组的低GWP制冷剂制冷循环特性分析

对比多种低GWP制冷剂在双级压缩与单级压缩制冷循环中的性能差异,并分析各制冷剂用于双级离心式冷水机组时,机组性能系数COP对有效过热度、过冷度、吸排气压损和压缩比分配系数(中间压力)等主要参数变化的敏感度.研究结果表明,低压替代制冷剂的安全性更优,且理想制冷循环的COP更高,但是其在变过冷度和变吸排气压损特性方面逊于中...