真空环境中硅胶-水工质对吸附平衡实验研究

文章基于真空称重法通过实验研究了不同吸附温度和吸附压力下,硅胶对水蒸气的吸附过程和平衡吸附量。实验结果表明,在同一吸附温度下,硅胶对水蒸气的吸附量随着相对吸附压力的升高而增大;当相对吸附压力一定时,硅胶对水蒸气的吸附量随着吸附温度的升高而减小。此外,文章还利用几种拟合方程对硅胶的吸附等温线进行拟合,并根据各方程拟合结果的相对误差确定适用于硅胶平衡吸附量的拟合方程。     

超临界燃料喷射过程大涡模拟:状态方程的影响

针对Sandia实验室关于正庚烷喷雾的实验数据，基于CONVERGE软件采用大涡模拟方法对以正庚烷为燃料喷入超临界环境中的雾化过程进行了数值模拟。以实际气体状态方程Soave-Redlich-Kwong (SRK)和Peng-Robinson(PR)两个方程为基础，重点研究了两状态方程对超临界状态下燃料喷雾的发展过程、射流密度变化、燃料喷雾的质量分数随温度变化的影响，并用模拟所得与实验结果进行对比。结果表明，同一时间下PR方程模拟的燃料喷雾的贯穿度更大；两实际气体状态方程下射流表面都有大的密度梯度，并与实验所得的密度值相吻合；PR方程对于超临界工况的计算可能更优于SRK方程。燃料质量分数随温度的变化符合实际的情况，密度值的急剧变化验证了射流表面是一个介于液体与超临界流体之间的混合层，并可以通过密度梯度来推测混合层位置。     

活性炭纤维吸附低体积分数苯的实验研究

研究了黏胶基活性炭纤维(activated carbon fiber, ACF)对非极性苯蒸汽的吸附.活性炭纤维比颗粒活性炭具有更高的吸附能力和更快的吸附动力且能有效去除挥发性有机化合物(volatile organic compounds, VOCs),活性炭纤维吸附剂其比表面积与孔结构通过氮吸附来表征.活性炭纤维样品上的苯吸附与脱附则通过热重方法测量,用DR方程对实验得到的吸附等温线进行拟合.实验结果表明,吸附量随活性炭纤维比表面积的增加而增加,而脱附过程则需100 min左右.     

不同状态方程对R134a摩擦理论黏度模型的比较分析

为了考察不同状态方程对摩擦理论黏度模型拟合结果的影响,以制冷剂R134a为例,分别采用工程上常用的PR(Peng-Robinson)方程、MBWR(modified benediet-webbrubin)方程和R134a的专用状态方程Span-Wagner方程建立了R134a的摩擦理论黏度模型.计算结果表明,用这三个方...     

碳纳米纤维吸附储氢性能评价

利用N2(T=77K)、H2(T=298K)在三种碳纳米纤维材料中的吸附等温线，对这三种材料的吸附储氢性能进行了评价。以N2在77K下的吸附等温线为基础，分别用BET方法和BJH方法计算了这三种材料的比表面积和孔径分布，讨论了比表面积、孔径分布和吸附性能之间的关系。计算和实验结果表明：这三种材料均只含有少量的微孔，吸附性能较差。在三种后处理方法中，以水蒸气氧化法的效果最好，所得材料比表面积最大，微孔容积所占比例也最大，相应的吸附性能也最好。     

新型化学吸附式制冷工质对CoF2-NH3的吸附特性

对新型化学吸附式制冷工质对CoF2-NH3的吸附特性进行了实验研究，得出了吸附等温线，研究结果表明，CoF2-NH3工质对的单位吸附量大，达到最大吸附量时的温度要求降低，吸附周期缩短，并且多次重复吸附后既不结块，也不膨胀，为化学吸附式制冷的小型化和实用化提供了新的可能性。     

SrCl2—NH3化学吸附式制冷工质对吸附特性的研究

对以SrCl2为吸附剂、NH3为致冷剂所组成的化吸附式制冷工质对的吸附性能进行了研究,得到了吸附等温线、回归出吸附等温方程并对化学吸附过程机理进行了探讨。研究结果表明,SrCl2－NH3工质对的吸附制冷量在,适宜太阳能或低品位余热驱动,是性能优良的工质对。     

适用于燃气STIG循环中湿燃气的状态方程

将燃煤气的ＳＴＩＧ循环中湿燃气当作实际气体处理，利用两项维里方程的 对比态形式，建立了湿燃气的状态方程，用此状态方程及余函数修正法计算了湿 燃气的热力性质，并与按理想气体计算的湿燃气的热力性质进行了比较。     

太阳能固体吸附式制冷吸附床的设计

描述了固体吸附式制冷系统中吸附床的作用和功能,比较分析了现有太阳能固体吸附式制冷装置的吸附床。通过两种吸附床装置的具体分析,提出了合理设计太阳能吸附床装置的途径。     

活性炭-R134a吸附性能的研究

吸附式制冷可用于汽车空调,由发动机的余热驱动,不消耗发动机的输出功。汽车空调对密封性和安全性要求较高,活性炭-R134a较符合该要求,搭建了测量活性炭-R134a吸附性能试验台,对该工质对在不同条件下的平均吸附量进行了测试,并得到了适用于该工质对的吸附率方程。     

天然气和氢气吸附储存吸附热研究现状

吸附热效应是天然气—氢气吸附储存投入工程应用的又一大障碍，吸脱附过程当中的放热、吸热现象极大地降低了吸附系统的动态储存量。在常温快速充气时，床层有较大的温升；在常温快速脱附时，床层中心的温度大幅度下降，极大的增加了甲烷残存量。该文综述了前人针对吸附热问题在实验上的研究，总结了前人提出的各种吸附热问题的解决方案，并对新的研究方向进行了探索。     

Adsorption mechanism and improvements of the adsorption equation for adsorption refrigeration pairs

An improved adsorption model for adsorption refrigeration pairs such as activated carbon–methanol and zeolite–water is suggested based upon normal Dubinin adsorption equations. This model has been verified by various experimental results. Copyright © 1999 John Wiley & Sons, Ltd.     

沸石分子筛-水吸附工质对的吸附性能及导热性能

吸附工质对的吸附和传热性能是研究吸附式干燥、除湿及制冷的重要基础，由于吸附量与导热系数和吸附材料的性质、温度、压力等许多因素有关，需要通过实验来确定。该文通过对几种沸石分子筛的性能实验研究，测定了其最大吸附量、密度、吸附等压线及导热系数等一系列性能参数及其影响因素，并给出了实际循环过程中吸附床的温度、压力与吸附量之间的关系。研究表明沸石对水的吸附基本满足D—A方程，而沸石导热系数受温度以及吸附量的影响较大，随着温度及吸附量的增加而增加。     

Immobilization of Heavy Metals and Phenol on Altered Bituminous Coals

Abstract

This article evaluates adsorption ability of the altered bituminous coals to remove heavy metals and/or phenol from aqueous solutions. As for heavy metals, copper (II), cadmium (II) and lead (II) cations were used. In addition to phenol, cyclohexanol and 2-cyclohexen-1-ol were also examined. Adsorption experiments were conducted in the batch mode at room temperature and at pH 3 and 5. To characterize the texture of coal samples, adsorption isotherms of nitrogen at ?196°C, enthalpies of the immersion in water, and pH values in aqueous dispersions were measured. Coal hydrogen aromaticities were evaluated from the infrared spectrometric examinations (DRIFTS). Based on the investigations performed, cation exchange was confirmed as the principal mechanism to immobilize heavy metallic ions on coals. However, apart from carboxylic groups, other functionalities (hydroxyl groups) were found to be involved in the adsorption process. During adsorption of phenol, π-π interactions between π-electrons of phenol and aromatic rings of coal proved to play the important role; however, no distinct correlation between adsorption capacities for phenol and hydrogen aromaticities of the coal was found. Probable involvement of oxygenated surface groups in the immobilization of phenol on coal was deduced. As a result, for waste water treatment, oxidative altered bituminous coal can be recommended as a suitable precursor, with the largest immobilization capacities both for metallic ions and phenol, as found in the studied samples.     

吸附剂固化的发展与固化活性炭块的试验研究

吸附剂的固化成型被认为是增大吸附式制冷系统的制冷量一个可行的方法。本文一方面综述了吸附系统中吸附剂固化的发展现状，讨论各种固化技术和方法。另一方面总结了在我们实验室所涉及的活性炭固化研究工作，给出了以块状活性炭一甲醇为吸附工质对时比较合适的固化工艺参数。     

合成应用于木质纤维素水解液精制的吸附树脂

对稀酸水解液进行精制脱毒是生化法中高效利用木质纤维素类生物质不可缺少的处理过程。本文以三种混合木质纤维素类生物质水解液为研究对象,以苯乙烯等为原料合成吸附树脂,考察了二乙烯基苯（DVB）浓度、单体和交联剂比例、非极性和弱极性单体等条件对吸附树脂吸附效果的影响。研究发现,固液比1.4∶40的情况下,不经过任何其他工艺,仅用吸附树脂,糠醛的去除率可以达到76%以上,5-羟甲基糠醛去除率可超过40%,可溶性木质素的最高去除率约为87%,而总糖损失率在8%左右。一定范围内提高交联剂的量可提高树脂的吸附性能,从而提高抑制剂的去除率。添加丙烯酸甲酯（MA）单体来改变树脂的极性,并不能提高树脂对每种抑制剂的吸附。     

The competitive adsorption behavior of CO and H2 molecules on FeO surface in the reduction process

The competitive adsorption behavior of CO and H₂ molecules on FeO surface in the reduction process was investigated by TG (thermogravimetry) experiments and MD (molecular dynamics) simulation. The model based on the Langmuir adsorption equations was built to describe the adsorption ability of CO and H₂ molecules on the FeO surface. The results show that: oxygen atoms cooperate with iron atoms to have influences on the adsorption ability of CO molecules. When the Fe mole fraction is higher than the critical value of 0.57, the governed factor of carbon monoxide's adsorption is converted from oxygen atoms to iron atoms, but the hydrogen's adsorption is only governed by oxygen atoms on the FeO surface. The experimental results is offered by the explanations that there exist a attractive force between carbon atoms and iron atoms and carbon monoxide could be spontaneously adsorbed on the iron shell of FeO surface while the adsorption of hydrogen on the iron shell is unstable. The high temperature will weaken strength of carbon monoxide's adsorption because of a negative effect on the adsorption energy.     

多壁碳纳米管吸附储氢性能的研究

采用容量法研究温度在273～300K范围内,压力升高到10MPa时多壁碳纳米管的吸附储氢性能.采用SEM、 TEM和低温N2吸附对碳纳米管的微观结构进行表征.结果发现,在相同压力下吸附量随温度的增加而降低,表明碳纳米管的吸附主要是物理吸附.采用Clausius-Clapeyron方程解析了氢气在碳纳米管上的等量吸附热,平均值为9.1kJ/mol.     

吸附制冷系统吸附床传热过程的数值模拟

为缩短吸附制冷周期,采用两床交替吸附/解吸结构,并采用管内走传热介质,管外填充吸附剂的吸附式制冷系统。建立了相应的数学模型。用数值方法对模型进行了求解,着重对吸附床温度场分布进行了数值模拟,并对吸附床内压力,某些点温度以及吸附量随时间的动态变化进行了模拟,得出的结果与实际情况吻合较好,说明此吸附制冷系统有较好的传热效果,为吸附床的优化设计提供了参考依据。     

Improvement of both adsorption performance of silica gel and heat transfer characteristics by means of heat exchange modulation for a heat pump

In order to provide high performance silica gel for an adsorption heat pump (AHP), gels were synthesized using the sol-gel process modified with a new method of controlling the primary gel particle growth by the addition of aluminum ion. In this process, the pores of the silica gel synthesized became smaller when aluminum ion was added in the washing process. Furthermore, this silica gel adsorbed more water at a low region of water vapor pressure and its adsorption ability did not change after 100 repetitive times of adsorping/desorping water vapor. The experimental results from the water vapor adsorption on the silica gel agreed well with theoretical results obtained under the Lump model for heat transfer and intraparticle diffusion model for mass transfer. A new direct heat exchange silica gel module (DS-module) for the AHP was provided, and the heat transfer characteristics during the operation for the adsorption of water vapor were both experimentally and theoretically determined. The period of the adsorption for the DS-module was shorter than that for a silica gel/tube module. Therefore, with the addition of the DS-module the heat transfer in the AHP adsorber was sufficiently enhanced and the maximum heat generation power for the 2-mm-thick DS-module was obtained. © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 25(7): 420–433, 1996