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Investigation of energy-efficient solid desiccant system for wheat drying

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International Journal of Agricultural and Biological Engineering 2019年第1期12卷 221-228页

作者： Shazia Hanif Muhammad Sultan Takahiko Miyazaki shigeru koyama Interdisciplinary Graduate School of Engineering Sciences Kyushu UniversityFukuoka 816-8580Japan Department of Agricultural Engineering Bahauddin Zakariya UniversityMultan 60800Pakistan Faculty of Engineering Sciences Kyushu UniversityFukuoka 816-8580Japan International Institute for Carbon-Neutral Energy Research(WPI-I2CNER) Kyushu UniversityFukuoka 819-0395Japan

The study investigates the applicability of solid desiccant system for drying of freshly harvested wheat grains in order to reduce the moisture content to an optimum level.Fast and low-temperature drying systems are required by today’s drying industries in order to provide economical and safe drying.Therefore,comparison of desiccant drying has been made with the conventional method in terms of drying kinetics,allowable time for safe storage,the total time for drying cycle,and overall energy consumption.It has been found that the air conditions of proposed desiccant drying system provides a high drying rate and longer allowable storage time for safe drying.As the desiccants possess water adsorbing ability by means of vapor pressure deficit,therefore,the desiccant system successfully provides low-temperature drying which ensures the quality of wheat grains.Overall energy consumption is estimated for both conventional hot air drying and desiccant drying system.It has been found that the desiccant system requires less energy as drying is accomplished at minimum level of air flow and within allowable storage time.In addition,the overall performance index of the desiccant system is higher at all temperatures.The study is useful for developing a low-cost and sustainable drying technology for various agricultural products.

关键词： desiccant solid desiccant system drying grain wheat performance evaluation

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微通道内超临界二氧化碳的压降与传热特性

工程热物理学报 2004年第5期25卷 843-845页

作者：淮秀兰 shigeru koyama 中国科学院工程热物理研究所北京100080 Institute for Materials Chemistry and Engineering Kyushu UniversityFukuoka 816-8580Japan

进行了微通道内超临界CO2的局部和平均传热与压降特性实验研究。结果表明,临界点附近物性参数的剧烈变化使压降增大,但传热被大大强化。同时也发现,系统压力、质量流速及CO2温度对流动与传热特性有重要影响。在大量实验数据的基础上,... 详细信息

进行了微通道内超临界CO2的局部和平均传热与压降特性实验研究。结果表明,临界点附近物性参数的剧烈变化使压降增大,但传热被大大强化。同时也发现,系统压力、质量流速及CO2温度对流动与传热特性有重要影响。在大量实验数据的基础上,得出了冷却条件下水平微通道内超临界CO2强制对流换热关联式。

关键词：超临界CO2 传热压降微通道

Endoscopic diagnosis of Barrett's esophagus

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World Journal of Gastroenterology 2012年第26期18卷 3477-3478页

作者： Tomoyuki Akiyama Yusuke Sekino Hiroshi Iida shigeru koyama Eiji Gotoh Shin Maeda Atsushi Nakajima Masahiko Inamori Department of Gastroenterology Tokyo Metropolitan Hiroo HospitalTokyo 150-0013Japan Gastroenterology Division Yokohama City University HospitalYokohama 2360004Japan Department of Medical Education Yokohama City University School of MedicineYokohama 2360004Japan Office of Postgraduate Medical Education Yokohama City University HospitalYokohama 2360004Japan

The Prague C and M Criteria have been developed for the objective endoscopic diagnosis of Barrett's esophagus(BE).BE arises between the squamocolumnar junction and the gastroesophageal junction at the proximal margin of the gastric folds.In this study,we reported that 43.0% of the subjects examined were diagnosed with BE based on the Prague C and M Criteria.Previous criticism by John Dent proposed that our data should be considered invalid because the prevalence of BE reported in our study was extraordinarily high and discordant with previous studies.Dent predicted that the position of the gastroesophageal junction in our study was judged to be lower than the actual position due to the effacement of the proximal ends of the gastric folds because of the routine use of a high degree of air distension during typical Japanese endoscopic examinations.The endoscopic evaluation of the superior gastric folds is certainly influenced by the degree of air distension of the esophagus.However,in our study,the proximal limit of the gastric mucosal folds was prospectively imaged while the oesophagus was minimally insufflated.Then,under a high level of air distension,the distal ends of the palisade-shaped longitudinal vessels were imaged because they are more easily observed when distended.In the majority of patients,the distal ends of the palisade-shaped longitudinal vessels correspond to the proximal limit of the gastric mucosal folds.Our endoscopic evaluation was appropriately performed according to the Prague C and M Criteria.We suspect that the high prevalence of BE in our study may be due to the inclusion of ultrashort-segment BE,which defines BE with an affected mucosal length under 5 mm,in our positive results.

关键词：内镜食管诊断胃粘膜布拉格交界处患病率标准

Experimental and Theoretical Analysis of the Impinging Stream Drying

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Chinese Journal of Chemical Engineering 2003年第1期11卷 42-48页

作者：淮秀兰刘登瀛 shigerukoyama Instituteof Engineering Thermophysics Chinese Academy of Sciences Instituteof Advanced Material Study Kyushu University

The experiments of one-stage semi-circular and two-stage semi-circular impinging stream drying as well as the vertical and semi-cricular combined impinging stream drying were carried out.The velocity distribution and the mean residence time of particles,and the influence of various factors on drying characteristics were studied.A mathematical model of granular material drying in a semi-circular impinging stream dryer was proposed,in which the flow characteristics as well as the heat and mass transfer mechanisms were considered.Reasonable numerical methods were used to solve the equations.Under various conditons,the calculated results of drying rate and moisture content versus time were obtained.The results indicate that constant drying rate period does not exist in a semi-circular impinging stream dryer.Appropriate semi-cricular stage number and curvature radius,flow-rate ratio,air velocity,and higher inlet air temperature should be used for enhancing the drying process.

关键词：撞流干燥化工过程实验研究理论研究 ISD

A Loop Thermosyphon Type Cooling System for High Heat Flux

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Journal of Electronics Cooling and Thermal Control 2014年第4期4卷 128-137页

作者： Jiwon Yeo Seiya Yamashita Mizuki Hayashida shigeru koyama Interdisciplinary Graduate School of Engineering Sciences Kyushu University Fukuoka Japan Faculty of Engineering Sciences Kyushu University Fukuoka Japan International Institute for Carbon-Neutral Energy Research (WPI-I2CNER) Kyushu University Fukuoka Japan

With rapid development of the semiconductor technology, more efficient cooling systems for electronic devices are needed. In this situation, in the present study, a loop thermosyphon type cooling system, which is composed mainly of a heating block, an evaporator and an air-cooled condenser, is investigated experimentally in order to evaluate the cooling performance. At first, it is examined that the optimum volume filling rate of this cooling system is approximately 40%. Next, four kinds of working fluids, R1234ze(E), R1234ze(Z), R134a and ethanol, are tested using a blasted heat transfer surface of the evaporator. In cases of R1234ze(E), R1234ze(Z), R134a and ethanol, the effective heat flux, at which the heating block surface temperature reaches 70°C, is 116 W/cm2, 106 W/cm2, 104 W/cm2 and 60 W/cm2, respectively. This result indicates that R1234ze(E) is the most suitable for the present cooling system. The minimum boiling thermal resistance of R1234ze(E) is 0.05 (cm2·K)/W around the effective heat flux of 100 W/cm2. Finally, four kinds of heat transfer surfaces of the evaporator, smooth, blasted, copper-plated and finned surfaces, are tested using R1234ze(E) as working fluid. The boiling thermal resistance of the blasted surface is the smallest among tested heat transfer surfaces up to 116 W/cm2 in effective heat flux. However, it increases drastically due to the appearance of dry-patch if the effective heat flux exceeds 116 W/cm2. On the other hand, in cases of copper-plated and finned surfaces, the dry-patch does not appear up to 150 W/cm2 in effective heat flux, and the boiling thermal resistances of those surfaces keep 0.1 (cm2·K)/W.

关键词： Cooling Boiling Loop Thermosyphon Grobal Warming Potential Thermal Resistance

Constraints of Adsorption Cooling Cycles Working at Partial Vacuum and Pressurized Conditions

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Constraints of Adsorption Cooling Cycles Working at Partial ...

2008国际低温与制冷大会

作者： Bidyut Baran Saha Ibrahim I El-sharkawy Anutosh Chakraborty shigeru koyama Interdisciplinary Graduate School of Engineering Sciences Kyushu University

＜正＞The objective of this paper is to consolidate the outcomes of a systematic investigation on the use of adsorption phenomenon for cooling.The performance analysis of thermally driven adsorption cooling cycles working in both partial vacuum and pressurized conditions is presented.Six adsorbent and refrigerant pairs namely the activated carbon fiber ACF（A-20）/ethanol,MaxsorbⅢ/ethanol, silica gel/water,Fluka/R134a,Chemviron/R134a and MaxsorbⅡ/R134a pairs have been investigated. The relationships between equilibrium pressures,adsorbent temperatures and equilibrium adsorption concentrations（P-T-W diagram） have been presented.Theoretical analysis shows that the former three pairs,i.***.the adsorption cycles working at partial vacuum pressures are suitable for surface cooling while latter three,i.***.those working at pressurized conditions are suitable for micro cooling applications.

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回热器对跨临界CO_2热泵系统性能的影响

西南交通大学学报 2012年第4期47卷 634-638页

作者：金东旭王平小山繁高田信夫大连理工大学能源与动力学院辽宁大连116024 九州大学综合理工学研究院

为了研究跨临界CO2热泵热水系统中,回热器传热面积对系统性能的影响,在不同的制冷剂充注量条件下实验研究了CO2热泵系统的性能.实验中,通过调节变频压缩机频率与电子膨胀阀开启度,保持了一定的制热量与蒸发器出口过热度.实验结果表明:... 详细信息

为了研究跨临界CO2热泵热水系统中,回热器传热面积对系统性能的影响,在不同的制冷剂充注量条件下实验研究了CO2热泵系统的性能.实验中,通过调节变频压缩机频率与电子膨胀阀开启度,保持了一定的制热量与蒸发器出口过热度.实验结果表明:在最佳制冷剂充注量条件下,随着回热器传热面积的增加,压缩机的压缩比下降,排气温度与吸气温度上升.采用回热器可以提高系统的最大制热系数,当回热器的无量纲传热面积为0.2时,可使最大制热系数提高约3.2%～5.1%.

关键词： CO2 热泵回热器性能

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跨临界CO_2热泵热水器的性能

西南交通大学学报 2010年第5期45卷 680-684页

作者：金东旭小山繁薛隽高田信夫大连理工大学能源与动力学院辽宁大连116024 九州大学综合理工学研究院

为了研究跨临界CO2热泵热水器制冷剂充注量对制热系数的影响,通过调节变频压缩机频率与电子膨胀阀脉冲,在制热量与压缩机入口过热度一定的条件下,对制热系数、压缩比、吸气和排气压力等与制冷剂充注量的关系进行了实验研究.结果表明:随... 详细信息

为了研究跨临界CO2热泵热水器制冷剂充注量对制热系数的影响,通过调节变频压缩机频率与电子膨胀阀脉冲,在制热量与压缩机入口过热度一定的条件下,对制热系数、压缩比、吸气和排气压力等与制冷剂充注量的关系进行了实验研究.结果表明:随着制冷剂充注量的增加,压缩机的排气压力上升,气体冷却器出口制冷剂的温度下降;随着蒸发器中热源水入口温度的上升,吸气压力上升,压缩比和排气温度下降;最大制热系数随热源水入口温度的上升而增大.当热源水入口温度为15℃且压缩机入口过热度为5℃时,系统的最大制热系数为3.25,最佳制冷剂充注量为1.7 kg.

关键词： CO2 制冷剂跨临界循环热泵性能

Application of simple adaptive control to water hydraulic servo cylinder system

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材料与冶金学报 2010年第4期9卷 300-303页

作者： Tsuyoshi YAMADA Kazuhisa ITO shigeru IKEO Masaharu NISHIMURA Graduate School of Engineering Tottori University 4 - 101 Minami Koyama - cho Tottori Japan Department of Machinery ＆ Control Systems College of Systems Engineering and Science Shibaura Institute of Technology 307 Fukasaku Saitama Japan Department of Mechanical Engineering Sophia University 7 - 1 Kioicho Chiyodaku Tokyo Japan

In this research, the positioning control of water hydraulic servo cylinder system with the simple adaptive control (SAC) is discussed. Conventional model reference adaptive control (MRAC) also achieves good tracking performance for cylinder control, but the controller structure was much complicated and was not easy to be realized in application. Compared with MRAC, SAC has simpler and lower order structure, i.e., has higher feasibility. But only few papers concerning with the application of the control performance of SAC to hydraulics and pneumatics are available, especially for water hydraulics. In this paper, we will examine and evaluate the control performance of the SAC strategy and it is confirmed that SAC gives better tracking performance compared with PI control.

关键词： water hydraulics servo cylinder system position control simple adaptive control