中国制冷空调行业制冷剂替代策略的思考

中国制冷空调行业淘汰HCFCs面临国际上的巨大压力和挑战。为此,从直接排放和间接排放2个方面对制冷剂应用对环境影响以及从制冷剂管理方面进行分析与阐述,提出制冷空调行业应负责任地使用制冷剂:提高制冷空调设备效率,降低制冷剂间接排放,减少制冷剂充注量,加强控制制冷剂泄漏,提高制冷剂回收、再生利用率来减少制冷剂的直接排放;应进行可燃制冷剂应用的基础研究和制定产品及应用安全标准,寻找对环境影响最小、经济可行、替代成本市场可接受、安全的替代制冷剂。同时建议行业协会配合国家有关部门制定适合中国国情的HFCs制冷剂的减排基准线和减排时间表。     

R32制冷剂空调压缩机应用试验研究

R22 制冷剂替换在即,R32 制冷剂是一种潜在的且经济的替代制冷剂.本文通过分析R32制冷剂的物理性质和理论热工循环参数,并采用空调用涡旋式压缩机进行试验测试,同时与 R410A 制冷剂进行试验对比.试验结果表明,R32 制冷剂替代当前的 R22 制冷剂作为空调制冷剂应用,对于空调用涡旋式压缩机来说,其整体表现与 R410A 制冷剂相类似.但为了取得更好的性能和可靠性,压缩机应针对 R32 制冷剂在空调工况应用时压力高、排气温度高的特点进行设计改进.     

Greencool制冷剂的特点及应用

本文介绍一种具有环保与节能效果的新型制冷剂-Greencool制冷剂,主要介绍这种制冷剂的特点并与传统的氟里昂制冷剂相比较.另外,本文还将介绍Greencool制冷剂的工程应用.     

从全球气候变化看制冷剂的替代

从目前全球气候变化与制冷剂应用的关系角度,简述了制冷剂以及其特性,指出现行制冷剂在温室效应及臭氧层破坏方面对气候变化的影响。介绍了当前在寻求环保制冷剂替代工作的进展情况,分析了环保制冷剂所必备的条件,在制冷剂的替代方面给出建议。     

我国空调用制冷剂回收再生的机遇与挑战

中国是全世界最大的制冷设备与制冷剂生产国和消费国,全球制冷剂超过1/3的需求量来自中国。预计至2030年,我国制冷空调行业制冷剂消费总量将达15.4~17.8万吨。本文介绍了国内外制冷剂回收再生技术及设备现状;调研了国内外对于制冷剂回收、净化再利用的相关标准,以及制冷剂中不同污染物含量的检测方法;分析了常用的传统制冷剂碳排放评价指标及优缺点,探讨了一种适合制冷剂回收再生过程的制冷剂气候性能评估指标;提出制冷剂回收、净化再利用的机遇与挑战。     

当前制冷剂替代品发展态势及我国制冷剂生产现状

我国是制冷剂生产和消费大国,目前制冷剂的替代已进入关键时期,如何有效地实现制冷剂的替代是我国制冷空调行业未来一段时期面临的严峻考验.本文介绍国际主要行业组织对制冷剂替代品评价和推荐情况,并概述我国制冷剂的生产及新一代制冷剂替代品的研发情况.     

国内外大中型冷库制冷剂的现状和发展动向

根据对国内外大中型冷库制冷剂使用情况的调研,分析了大中型冷库制冷剂的现状.根据国际上最新的文献,评论了冷库制冷剂应用的发展新动向.结果表明:在国内外大中型冷库中,目前采用氨制冷剂是主流,今后氨仍然将是主要制冷剂.在蒸发温度-35℃以上,压缩式制冷采用氨制冷剂是最节能的.采用氨制冷剂的关键问题是安全问题.在制冷剂的发展动向中,CO2系统成为新一代制冷剂关注的重点,CO2/NH3复叠式制冷系统具有较大的发展潜力.在间接制冷系统中,采用氨水替代乙二醇作为载冷剂,可以使系统能耗明显降低.     

制冷剂替代技术研究进展及发展趋势

蒙特利尔议定书第19次缔约方会议通过了加速淘汰HCFCs制冷剂的调整案,给我国制冷行业带来了较大压力.根据联合国环境规划署“气候友好制冷剂之路”国际会议信息,介绍了制冷剂替代技术的国内外研究现状.欧盟正积极推进天然制冷剂的应用,美国杜邦公司等在开发和宣传化学合成制冷剂的优越性,而非洲、东南亚等发展中国家更关注制冷剂替代技术和替代资金的来源.我国在HCFCs替代方面,除了研究适合国情的R32等过渡制冷剂替代技术之外,还应该进一步研究CO2、R290等天然制冷剂的应用技术,同时开发GWP值较小但与HCFCs类制冷剂的物性更加接近的制冷剂.另外,这里还强调了HCFCs替代技术涉及到的相关标准的制订是行业发展的基础,应该受到特别关注.     

低碳制冷剂研究及应用最新进展

制冷剂是制冷系统的血液。自从人类有了合成制冷剂之后,制冷技术得以快速发展,但也导致了诸如臭氧层破坏、全球变暖效应等环境问题的出现,给传统合成制冷剂带来严峻的挑战。本文结合最新出版的联合国环境规划署制冷空调热泵技术选择委员会撰写的"蒙特利尔议定书2014评估报告",2015年8月在日本横滨召开的国际制冷学会第24届国际制冷大会的有关学术报告以及2014年召开的国际制冷学会第11届自然制冷剂大会的学术报告,总结制冷剂研究及应用的最新进展,包括不同类型制冷装置采用不同制冷剂的现状,新型低碳制冷剂的热物性、传热特性、安全性,可燃制冷剂国际标准的最新进展,以及新型低碳制冷剂在使用中应注意的问题,未来制冷剂替代可能的趋势等。     

制冷剂回收与再生现状分析

制冷剂回收和再生是减少制冷剂排放的推荐方式,但其实施有赖于政策的鼓励及回收再生技术的支持.对于制冷剂的回收,本文总结对比了日本、欧盟、美国和中国在制冷剂回收方面的政策,给出了各自的制冷剂年回收量;介绍了制冷剂回收5种代表性方法的工作原理、优缺点及适用的场合.对于制冷剂的再生,介绍了"简易再生"和"蒸馏再生"这2种再生方...     

Gender differences in publication productivity in psychology in India

An analysis of gender differences in psychology in India provides quantitative and qualitative assessment of R&D output contributed by psychologists with the indication of the trend of growth, skewness, relatedness, co-authorship pattern of productivity.     

Metrology in Chemistry in Germany

The system for Metrology in Chemistry in Germany is described. At the national standards level, a network of high-level chemistry institutes coordinated by the national metrology institute, PTB, provides the primary references for chemical measurements. A dissemination mechanism employs chemical calibration laboratories accredited within the framework of the German Calibration Service (DKD). They act as “multipliers” between the national standards level and the user level by providing the user with calibration means which are traceable to the SI via national standards. Traceability structures in clinical chemistry, electrochemistry, elemental analysis and gas analysis are described     

Natural radioactivity in drinking water in private wells in Finland

Natural radioactivity in drinking water was determined in population-based random study of 472 private wells. The mean concentrations of (222)Rn, (226)Ra, (234)U, (238)U, (210)Pb and (210)Po in drilled wells were 460, 0.05, 0.35, 0.26, 0.04 and 0.05 Bq l(-1), and in wells dug in the soil were 50, 0.016, 0.02, 0.015, 0.013 and 0.007 Bq l(-1), respectively. Approximately 10% of the drilled wells exceeded a radon concentration of 1000 Bq l(-1) and 18% a uranium concentration of 15 microg l(-1). The mean annual effective dose from natural radionuclides for a drilled well user was 0.4 mSv and 0.05 mSv for a user of a well dug in the soil. The effective dose arising from (222)Rn was 75% of the total of all natural radionuclides for drilled well users. As regards long-lived radionuclides, (210)Po and (210)Pb caused the largest portion of the effective dose. The dose arising from (238)U, (234)U and (226)Ra was only 8% of the total of all natural radionuclides.     

Natural radioactivity in drinking water in private wells in Finland

Radiation Protection Dosimetry     

Radioactivity in building materials in Iraq

Activity concentrations of (226)Ra, (232)Th and (40)K in 45 samples of different building materials used in Iraq were measured using gamma-spectroscopy system based on high-purity germanium detector with an efficiency of 40 %. Radium equivalent activity, air-absorbed dose rate, annual effective dose, external and internal hazard indices and alpha index due to radon inhalation originating from building materials were measured to assess the potential radiological hazard associated with these building materials. The activity concentrations of the natural radionuclides (226)Ra, (232)Th and 40K were found to range from below detection limit (BDL) to 223.7 ± 9, BDL to 93.0 ± 3 and BDL to 343.1 ± 12, respectively. Values of average radium equivalent activity, air-absorbed dose rate, indoor and outdoor annual effective doses, external and internal hazard indices and alpha index ranged from 6.5 to 124.9, 16.2 to 89.5 (nGy h(-1)), 0.08 to 0.44 mSv, 0.02-0.11 mSv, 0.09 to 0.53, 0.13 to 0.69 and 0.03 to 0.62, respectively. These values indicate a low dose. Therefore, the building materials used in the current study are quite safe to be used as building materials.     

Optische in situ Schichtdickenmessung in Bedampfungsanlagen. Optical in situ film thickness monitoring in coating systems

Optical film thickness monitoring is more precise than crystal monitoring. The optical measurement makes use of the fact that the intensity of a monochromatic light beam which is reflected on a film will change periodically with increasing film thickness. The measurement is performed at an exchangeable test glass that is positioned beside the substrates and is therefore coated in the same way as the substrates. The accuracy of cut‐off is achieved by a “fit” of a theoretical curve shape to the measured values. Order filters are used to ensure that, at a certain wavelength, higher deflection orders do not influence the measurement when a monochromator grating is used.