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Experimental adsorption equilibrium study and comparison of zeolite with water and ethanol for cooling systems

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Journal of zhejiang university-Science A(Applied Physics & Engineering) 2007年第2期8卷 216-220页

作者： MAIGA Abdoulaye Siddeye, CHEN Guang-ming, WANG Qin (institute of refrigeration and cryogenics, zhejiang university, hangzhou 310027, china) institute of refrigeration and cryogenics zhejiang university hangzhou 310027 china Ph.D student at Zhejing university from Mali

Two adsorption refrigeration working pairs of zeolite with water and ethanol were studied and the parameters of Dubinin-Astakhov model were regressed using the experimental data of equilibrium. The coefficient of heterogeneity varied from 1.305 to 1.52 for the zeolite-water pair and from 1.73 to 2.128 for zeolite-ethanol pair. The maximum adsorption capacity varied from 0.315 to 0.34 for zeolite-water and 0.23 to 0.28 for zeolite-ethanol, respectively. The results showed that the zeolite-water pair is suitable for solar energy cooling not only because of the high latent heat of vaporization of water but also because of the better equilibrium performance. On the other hand, zeolite-ethanol gives a high adsorption capacity at high regeneration tem-perature, which means it can be used in heat engine systems like buses and cars.

关键词： Adsorption refrigeration Zeolite Ethanol Water Equilibrium

Development of an automatic calibration device for high-accuracy low temperature thermometers

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Science china(Technological Sciences) 2010年第9期53卷 2404-2407页

作者： CHEN GuangMing,GAO Xu,ZHANG ShaoZhi,CHEN Qi,TANG LiMing & LAN YuQi institute of refrigeration and cryogenics,zhejiang university,hangzhou 310027,china institute of refrigeration and cryogenics Zhejiang University Hangzhou China

Based on the analysis and investigation of calibration systems for high-accuracy low temperature thermometers,a new facility for automatic calibration of high-accuracy low temperature thermometers was *** calibration for multiple points can be made automatically with this *** to the thermophysical characteristics of the constant-temperature block in this device,segmented Fuzzy-PID (proportional-integral-differential) algorithm was *** experimental results showed that the temperature fluctuation was smaller than ±0.005 K in 30 ***,this new device can fully meet the calibration requirement of high-precision low temperature thermometers.

关键词： calibration low temperature thermometer control algorithm

DISPLACEMENT CONTROL AND KINETIC ANALYSIS OF A NOVEL VARIABLE DISPLACEMENT COMPRESSOR FOR AUTOMOTIVE AIR CONDITIONER

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Chinese Journal of Mechanical Engineering 2001年第4期14卷 325-329页

作者： Yuan Xiaomei,Chen Zhijiu (institute of refrigeration and cryogenics Engineering, Shanghai Jiaotong university) 上海交通大学上海

A novel variable displacement compressor (VDC) for automotive air conditioner (AAC) is introduced, which inherits the advantages of common wobble plate type VDC. It has fewer parts and makes less noise, and instead of pneumatic valve the displacement is controlled by electronic control valve. In order to know the control mechanism well and get a good control effect, a mathematical model for the variable displacement mechanism is developed according to the geometrical and kinematical information of the compressor. Using the model, the effect of relevant parameters on variable displace control is estimated. It is helpful to make the optimum decision in the flow control of AAC. As the novel displacement control device, the structure and control rule of electronic control valve is introduced. It can get better effect than the conventional pneumatic valves. And by using this new electronic control device, the optimum systemic control of AAC is available.

关键词： Displacement control Kinetic analysis Automotive air conditioner (AAC) Variable displacement compressor(VDC)

Acoustic impedance characteristics of linear compressors

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Journal of zhejiang university-Science A(Applied Physics & Engineering) 2013年第7期14卷 494-503页

作者： Zhi-hua GAN Long-yi WANG Sheng-ying ZHAO Yu-jing SONG Wei-wei WANG Yi-nong WU institute of cryogenics and refrigeration Zhejiang University School of Information and Electrical Engineering Zhejiang University City College Shanghai institute of Technical Physics Chinese Academy of Sciences

The acoustic field of a linear compressor serves to deliver the compression work to the load, such as the connected cold head of a cryocooler; it plays an equivalently important role as the electrical and mechanical parts, especially in the impedance match issue. This paper studies the acoustic impedance characteristics of a linear compressor. The parameters including the current, the piston displacement, the pressure amplitude, the electrical power dissipation, the power factor, the pressure-volumetric (PV) power delivered, and the efficiency are theoretically and experimentally investigated. Different from previous theoretical studies, optimization for the operations away from the resonance is also included. More general optimization results imply relevance between thermoacoustic engines and linear compressors. The predicted results are validated by the experiments performed on a linear compressor with an adjustable resistive-capacitive (RC) acoustic load. The comparisons between the calculations and the measurements are presented and analyzed. The results provide deeper insight into the mechanism of the linear compressor and the impedance match in a cryocooler system.

关键词： Linear compressor Acoustic impedance Resistive-capacitive (RC) load

Gas hydrate fast nucleation from melting ice and quiescent growth along vertical heat transfer tube

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Science china Chemistry 2005年第1期48卷 75-82页

作者： XIE Yingming1,2, GUO Kaihua2, LIANG Deqing2, FAN Shuanshi2, GU Jianming1 & CHEN Jinggui2 1. institute of refrigeration and cryogenics, Shanghai Jiaotong university, Shanghai 200030, china 2. Guangzhou institute of Energy Conversion, The Chinese Academy of Sciences, Guangzhou 510640, china Inst. of refrigeration Shanghai Jiaotong Univ. Shanghai 200030 China Guangzhou Inst. of Energy Conversion Chinese Acad. of Sci. Guangzhou 510640 China

During the observation of HCFC141b gas hydrate growth processes outside a ver- tical heat transfer tube, two exciting phenomena were found: fast nucleation of gas hydrate from melting ice, and the spontaneous permeation of water into the guest phases along the surface of heat transfer tube to form gas hydrate continuously. These two phenomena were explained with Zhou & Sloan’s hypothesis and the theory of surface free energy respectively, and a novel method of gas hydrate formation was presented——gas hydrate fast nucleation from melting ice and quiescent growth along heat transfer tube. There is no mechanic stirring in this method, the formed gas hydrates are compact, the ratio of unreacted interstitial water is little, which overcome the drawback of high energy cost and high ratio of unreacted interstitial water among the formed gas hydrates in the system with mechanic stirring. This finding will benefit the gas hydrate ap- plication technologies such as natural gas storage technology or cool storage technology with gas hydrate.

关键词： gas hydrate, natural gas storage, cool storage, fast nucleation from melting ice, permeation, surface free energy.

RESEARCH ON MEASURING METHOD OF THE THERMALCONDUCTIVITY FOR HIGHLY POROUS MATERIALS

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Acta Metallurgica Sinica(English Letters) 1997年第3期10卷 213-218页

作者： J Y Wu Z.M. Tang W Shi andR.Z. Wang (institute of refrigeration and cryogenics Engineering, Shanghai Jiao Tong university, Shanghai 200030,china) Shanghai Jiaotong Univ Shanghai China

A transient method with rectangular pulse heating has been developed to measure the thermal conductivity of highly porous materials such as activated carbon, zeolite and silica gel. By this method the thermal conductivity can be measured quickly and accu-rately. In this paper, a set of automatically controlled testing equiptnent is *** measuring method is analysed. The thermal conductivities of some samples, such as activated carbon and zeolite, are measured by the equipment. A group of useful data has been obtained.

关键词： thermal conductivity porous material thermophysical property

Experimental Study on Capacity Modulation by Variable Composition of Refrigerant Mixture

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Experimental Study on Capacity Modulation by Variable Compos...

Effects of Ice Nucleation Bacteria on Water/Solid Model Food Freezing

2008国际低温与制冷大会

作者： Zhang L N Chen G M institute or refrigeration and cryogenics zhejiang university hangzhou 310027 P.R.china

＜正＞A new capacity-controlled heat pump system was developed in this *** experimental study on capacity control of a heat pump system by variable composition has been performed using refrigerant mixture of R32/*** experimental setup was made up of a refrigeration part and composition varying *** composition varying part with a rectifier and a reservoir was connected to the junction between the condenser outlet and compressor outlet and to the throttle valve *** of the refrigerant mixture from the compressor and the condenser goes into the rectifier,as a heat source so that the heat energy to the rectifier supplied generally by external sources can be *** the modulation occurs,the reservoir was used to store the high volatile component of the refrigerant mixture separated from the rectifier,the low volatile component together with lubricant flows back to the main *** capacity and coefficient of performance （COP） of the system were measured under the given *** results show that about 28% of composition change was *** the capacity of the system was improved by 33%as the composition of R32 increased.

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Effects of Ice Nucleation Bacteria on Water/Solid Model Food...

用于深度冷冻的自行复叠吸收制冷循环理论研究

2008国际低温与制冷大会

作者： Zhang S Z Wang H Y Chen G M institute of refrigeration and cryogenics zhejiang university hangzhou 310027 P.R.china

＜正＞Cells of ice nucleation active（INA） bacteria,Pseudomonas syringae,was cultured at 26℃with nutrient agar culture medium and harvested at early stationary phase（20h） for maximum ice nucleation *** cells were incorporated into water or solid model food to investigate their effects on degree of supercooling and characteristic freezing *** freezing temperatures were used,-15℃and -30℃.It was found that the degrees of supercooling of model foods with INA were reduced by 3℃to 4℃at all freezing *** characteristic freezing time was *** results imply that the ice nucleation bacteria may be used to modify the freezing process to save energy and the effects will be more obvious for higher freezing temperature and smaller sample size.

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太阳能学报 2002年第6期23卷 786-790页

作者：钟永芳陈光明浙江大学制冷与低温研究所杭州310027

提出了一种可利用热能获得深度冷冻的吸收制冷循环 ,通过对新循环与传统吸收制冷循环最低制冷温度的比较 ,证明新循环能取得比传统吸收式制冷低得多的蒸发温度。对新循环的不同工况进行了计算和分析。

关键词：深度冷冻自行复叠吸收制冷热能