氯化锶-氨吸附制冷性能的实验研究

建立了化学吸附式制冷实验单元，对氯化锶－氨工质对的制冷性能进行实验研究，得出不同热源温度下的制冷量，吸附速率、解吸速率等数据，并与活性炭－甲醇工质对进行了比较。     

太阳能固体吸附式制冰机不同吸附工质对的实验研究

在构建的太阳能制冰机的基础上，选用活性炭-甲醇、活性炭-乙醇作为吸附制冷工质对，在外界环境条件及辐射能量条件相同的条件下，分别对两种不同的吸附制冷工质对进行解吸量、吸附量和制冰量的实验。通过对大量实验数据的分析与整理，所得出的结论是：对固体吸附式制冰机装置而言，活性炭-甲醇工质对仍是最佳的吸附制冷工质对，活性炭-乙醇工质对不适合于太阳能固体吸附式制冰机中。     

采用床内强制对流进行传热传质的固体吸附式循环分析

采用一维两温度模型，以活性炭纤维－氨为工质对，模拟计算了对流热波循环的吸附床加热过程和冷却过程中床内的温度分布和变化趋势，并分析计算了对流热波循环的性能参数。系统的回热率达０．４，热泵效率达１．７８，热泵系统的能量密度为１６１６Ｗ／ｋｇ。对系统加以优化，可获得更高的回热率和ＣＯＰ。     

吸附式制冷机及空调/热泵的运行实验和性能改进

研制了一台采用螺旋板式吸附器的连续回热型吸附式制冷机和一台采用板翅式吸附器的空调／热泵,给出了实验数据。吸附式制冷系统采用活性炭－甲醇吸附工质对,以９０－１００℃絷不作为热源,实验得到单位质量活性炭的制冷能量密度为：制冰机每ｋｇ吸附剂日制冰２．６ｋｇ,空调／热泵组在空调工况下每ｋｇ吸附剂制冷功率为１５０Ｗ。     

动力循环中混合工质的应用研究

采用沸点不同的混合物，由于工质吸热蒸发是变温过程，使热源的放热过程与混合工质的吸热过程曲线更好的配合，最大限度地降低传热过程中的不可逆损失，同时热源的放热温度可以大大降低，根据混合工质的这一特点，设计了以氨-水混合物作为工质电冷联合生产的新型热力循环。该热力循环可以利用低温热源，如地热，低温太阳能，电厂废热等。对这一热力循环的经济性分析证明；该系统循环效率比单一工质效率高。     

国产活性炭－甲醇吸附式制冷性能研究

建立了一套活性炭－甲醇吸附容量测定试验台，对国产活性炭的吸附性能进行了测试，得到有关吸附方程式Ｄｕｂｉｎｉｎ－Ａｓｔａｋｈｏｖ（Ｄ－Ａ）的关联参数，并对国产活性炭－甲醇吸附式制冷循环进行了模拟计算，讨论了循环ＣＯＰ及单位质量活性炭制冷量Ｑｆ等主要参数。与国际上流行的活性炭ＡＣ－３５相比，国产活性炭材料作为固体吸附式制冷机的吸附剂；具有与ＡＣ－３５相近的ＣＯＰ，但单位质量制冷量Ｑｆ较ＡＣ－３５差些。     

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。     

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。     

一种有潜力的吸附式制冷工作对——活性炭纤维—甲醇

吸附式制冷具有无ＣＦＣｓ问题、可利用低品位热能驱动、价格效用比高等一系列优点。由于一般吸附剂吸附／解吸时间长和单位质量制冷功率小使吸附式制冷的产品化受阻。活性炭纤维是一般吸附剂活性炭的较好替代物，其对甲醇的吸附容量为活性炭的２－３倍，而吸附／解吸时间仅为活性炭的１／１０左右。对紧凑式吸附式冰箱，活性炭纤维－甲醇是一种好的工作对。     

基于海底黑烟囱的海洋温差发电热力循环系统研究

与传统的海洋温差发电系统不同,海底黑烟囱海洋温差发电系统是以海洋地热为热源,以深海冷水为冷源的发电系统。文章分别分析和计算了以水蒸气为工质的开式系统和以纯氨为工质的闭式系统的循环热效率、换热器负荷、泵耗以及循环净功等相关参数。结果表明,与以纯氨为工质的闭式系统相比,开式系统的热水泵功耗过大,降低高温海水的温度和提高闪蒸压力对开式系统是不利的;以水蒸气为动力循环工质有利于降低换热器的负荷,这对换热器的设计是十分有利的。     

吸附制冷工作对的吸附机理及其吸附率方程的改进

在Ｄ－Ａ吸附率方程的基础上提出适合于活性炭－甲醇,分子筛－水等吸附制冷工作对的改进型吸附率方程,并用一系列实验数据进行比较验证,证明该方程与实验数据吻合。     

Adsorption properties of a natural zeolite–water pair for use in adsorption cooling cycles

The equilibrium adsorption capacity of water on a natural zeolite has been experimentally determined at different zeolite temperatures and water vapor pressures for use in an adsorption cooling system. The Dubinin–Astakhov adsorption equilibrium model is fitted to experimental data with an acceptable error limit. Separate correlations are obtained for adsorption and desorption processes as well as a single correlation to model both processes. The isosteric heat of adsorption of water on zeolite has been calculated using the Clausius–Clapeyron equation as a function of adsorption capacity. The cyclic adsorption capacity swing for different condenser, evaporator and adsorbent temperatures is compared with that for the following adsorbent–refrigerant pairs: activated carbon–methanol; silica gel–water; and, zeolite 13X–water. Experimental results show that the maximum adsorption capacity of natural zeolite is nearly 0.12 kg_w/kg_ad for zeolite temperatures and water vapor pressures in the range 40–150 °C and 0.87–7.38 kPa.     

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.     

Thermodynamic design procedure for solid adsorption solar refrigerator

The thermodynamic design procedure for solid adsorption solar refrigeration is presented and applied to systems using activated carbon/methanol, activated carbon/ammonia and zeolite/water adsorbent/adsorbate pairs. The results obtained showed that zeolite/water is the best pair for air conditioning application while activated carbon/ammonia is preferred for ice making, deep freezing and food preservation. In all cases, the system depends strongly on adsorption and condensation temperatures and weakly on the evaporator temperature. The maximum possible net solar COP was found to be 0.3, 0.19 and 0.16 for zeolite/water, activated carbon/ammonia and activated carbon/methanol, respectively, when a conventional flat plate solar collector is used.     

油气吸附分离常用的数值模拟方法

油气吸附理论是利用活性炭、硅胶、沸石等吸附剂吸附回收油品蒸气的理论基础,可用来减少油品损耗、保护环境。油气吸附理论研究的不断深入,以及基于不同理论模型、适用于不同体系的油气吸附理论不断被提出,拓展了油气吸附的实际应用领域,本文分析了Langmuir、BET、吸附势及溶液吸附等4类常用的油气吸附模型,并指出了4种模型各自的适用范围和优缺点。对于单一气体或者理想的单分子层的气体,可以用Langmuir吸附模型;对于多分子层气体．可以使用扩展的Langmuir吸附模型或者BET吸附模型;吸附气体在临界温度以下时,用Grant—Manes吸附模型比较准确;“空穴”溶液模型（VSM）适用于共沸混合气体;随着计算机软件和硬件的发展,特别是一些大型商用软件和大型计算机工作站的出现,使得油气吸附模型可方便地进行离散化数值处理。     

Analysis of a Finned Heat Exchanger Working in an Adsorption Refrigeration System Using Zeolite and Methanol

A new refrigeration system that uses a specially designed finned plate heat exchanger and works with zeolite and methanol is proposed. The integration of heat transfer and adsorption via a finned surface coated with zeolite CBV 901 and the use of a connected, twin active bed system to enable heat recuperation are novel features. The thermophysical properties of zeolite and methanol were first studied with the intention of designing a high performance heat exchanger (generator) for the adsorption refrigeration system. Here, the major problem is related to poor conductivity at the interface between the heat exchanger and the zeolite. The adsorbent must be heated (desorption phase) and then cooled (adsorption phase) back to ambient temperature in order to complete a thermodynamic cycle. To manufacture a sufficiently small system, there must be high rates of heat transfer in and out of the adsorbent. Therefore, the surface of the heat exchanger is finned in order to increase the heat transfer area (the fins are coated with 2 mm layer of specially prepared zeolite paste). The following characteristics were estimated from initial calculation: heating temperature, 120°C; outside tube temperature, 119.6°C; middle fin temperature, 117°C; and coated layer of zeolite paste temperature, 115.3°C. The mathematical code developed to calculate the effects of operating conditions and the Coefficient of Performance (COP) was presented at HPC 2001 in Paris. It is based on the Dubinin-Astakhov equation and thermodynamic analyses. The results obtained shows that 0.535 is the COP for a single bed and 0.925 for a double bed.     

Performance of different zeolites as adsorbents for methane

The adsorption behavior of methane in simulated coal-bed gas on several micropore zeolites is studied. Alkali and steaming treatments of ZSM-5 are carried out in order to adjust the pore structure and to further elucidate the effect of pore structures on methane adsorption behavior. Further, the effect of adsorbed water on ZSM-5 zeolite is also considered. Textural properties of material are characterized by nitrogen adsorption-desorption at 77 K. The results indicate that pore structures of zeolite adsorbent have a more important effect on the adsorption performance, compared with the specific surface area. The presence of adsorbed water on micropore zeolite is unfavorable to the methane adsorption.     

Dynamic ammonia adsorption by FAU zeolites to below 0.1 ppm for hydrogen energy applications

Hydrogen can be released from ammonia (NH₃) by cracking, but the residual ammonia is harmful to polymer exchange membrane fuel cells and should be less than 0.1 ppm (μmol/mol). In this paper, the adsorption of NH₃ by commercial faujasite (FAU) zeolites to below 0.1 ppm have been investigated. The results show that the Si/Al ratio of zeolite is inversely proportional to the adsorption capacity, and the strength of ammonia adsorption by cation Li⁺ is more than that of Na⁺, thus the ammonia adsorption capacity of LiLSX zeolite is greater than that of 13X–HP zeolite. However, the small granule size of crystalline microspheres and the rough surface of 13X–HP zeolite were the factors that lead to the dynamic NH₃ adsorption capacity of 13X–HP zeolite close to LiLSX zeolite. In the dynamic 1700 ppm NH₃ adsorption, with a breakthrough point of 0.1 ppm, the adsorption capacity is 9.27 wt% for LiLSX zeolite and 8.73 wt% for 13X–HP zeolite.     

Hydrogen sulfide removal from biogas using ion-exchanged nanostructured NaA zeolite for fueling solid oxide fuel cells

Hydrogen sulfide is the most abundant sulfur compound in the biogas, and in order to use for fueling the solid oxide fuel cells, its content should be less than 1 ppm. In this work, NaA nano zeolite is synthesized hydrothermally and modified by Ag⁺ ions, and its breakthrough capacity for hydrogen sulfide adsorption was measured using dynamic lab-scale adsorption tests on the experimental set-up for the first time. The results are compared to those of unmodified NaA nano zeolite and micron-sized commercial 4A zeolite. AgNaA nano zeolite showed the highest adsorption capacity (33.24 mg H₂S/g of Sorbent) and the longest breakthrough time (310 min). The regeneration performance of AgNaA nano zeolite and its structural stability are also investigated after five cycles. The results revealed that the AgNaA nano zeolite could be used promisingly for removing hydrogen sulfide from biogas for cleaner energy production.