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首页> 外文期刊>International Journal of Heat and Mass Transfer >Experimental testing and analysis of R134a clathrates based PCMs for cooling applications
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Experimental testing and analysis of R134a clathrates based PCMs for cooling applications

机译：基于R134a包合物的PCM用于冷却应用的实验测试和分析

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摘要

An experimental investigation is conducted to test the thermal behavior and characteristics of R134a clathrates with additives, as phase change materials (PCMs). PCMs' charging characteristics are analysed and evaluated for cooling applications. The formation of refrigerant clathrates is investigated due to their potential use in active as well as in passive cooling applications. PCMs are formed using R134a clathrate and distilled water with different refrigerant proportions and five different additives. The main objective of using additives is to study their potential for enhancing the clathrate formation and their thermodynamics properties under direct contact heat transfer. PCMs are formed in glass tubes and their freezing on-set and transformation time is recorded. The refrigerant R134a percentages of 15%, 20%, 25%, 30%, 35% and 40% are used to form clathrate. For the additives, ethanol, sodium chloride, magnesium nitrate hex-ahydrate, copper and aluminum are used. PCMs are formed using controllable constant temperature water. Time for initial on-set until the time the clathrate structure does not change (end-set) is recorded after regular intervals. The low charging time shows that the PCM requires low energy input to change its phase where as more time shows that PCM takes more energy to do so. Energy and exergy analyses are also performed to determine their utilization. A comparative study is conducted to compare the charging times for different PCMs using the suggested additives. R134a refrigerant clathrate without any additive is used as the base case for comparison. R134a proportion of 35% is found to be the best mass ratio for clathrate formation since it required the least amount of time and energy. Copper additive reduces the onset time while magnesium nitrate hexahydrate reduces the end-set time the most. Sodium chloride is found to increase the formation time, and at high mass proportions, it does not allow clathrate formation.
机译：进行了实验研究，以测试具有相变材料（PCM）的R134a包合物的热行为和特性。针对冷却应用，分析并评估了PCM的充电特性。由于制冷剂包合物在主动和被动冷却应用中的潜在用途，因此对其进行了研究。 PCM是使用R134a笼形水和蒸馏水制成的，其中的冷却剂比例不同，并且添加了五种不同的添加剂。使用添加剂的主要目的是研究其在直接接触传热下增强包合物形成的潜力及其热力学性质。 PCM在玻璃管中形成，并记录其冻结开始时间和转变时间。 15％，20％，25％，30％，35％和40％的制冷剂R134a百分比用于形成包合物。对于添加剂，使用乙醇，氯化钠，六水合硝酸镁，铜和铝。 PCM是使用可控的恒温水形成的。在有规律的间隔后，记录初次开始直到包合物结构不变的时间（结束设定）的时间。低充电时间表明PCM需要低能量输入来改变其相位，而更多的时间表明PCM需要更多的能量来改变相位。还进行能量和火用分析以确定其利用率。使用建议的添加剂进行了一项比较研究，以比较不同PCM的充电时间。不含任何添加剂的R134a制冷剂包合物用作比较的基本情况。发现R134a比例为35％是包合物形成的最佳质量比，因为它需要最少的时间和能量。铜添加剂可以缩短起效时间，而六水合硝酸镁可以最大程度地缩短起效时间。发现氯化钠增加了形成时间，并且在高的质量比例下，它不允许包合物的形成。

著录项

  • 来源
    《International Journal of Heat and Mass Transfer》 |2015年第12期|756-765|共10页
  • 作者

    Sayem Zafar; Ibrahim Dincer; Mohamed Gadalla;

  • 作者单位

    Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario L1H 7K4, Canada;

    Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario L1H 7K4, Canada ,Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 34464, Saudi Arabia;

    Department of Mechanical Engineering, American University of Sharjah, Sharjah, United Arab Emirates;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    R134a clathrate; Refrigerant; Cooling; Heat transfer; PCM; Additives;

    机译：R134a包合物;制冷剂冷却;传播热量;PCM;添加剂类;

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