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Volume 20 (2003)
- Issue 4 Pages 437-
- Issue 3 Pages 287-
- Issue 2 Pages 111-
- Issue 1 Pages 1-
Volume 20, Issue 4
Displaying 1-9 of 9 articles from this issue
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Atusi SUDO, Akinari SUDO2003 Volume 20 Issue 4 Pages 437-448
Published: 2003
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSThe air-cooled refrigerator for cold districts has been developed in response of the necessity of cold storage of apples over a long time of one year. The refrigerators have suffered the trouble of a compressor suction valve in practical use on the winter season, which is often caused by a pulsating flow of liquid refrigerant induced at sudden rise of condenser temperature. The trouble was settled by use of a large size dryer, which played additional roles of al iquid reservoir and an accumlator, in place of an old dryer.View full abstractDownload PDF (588K) -
Waste Heat Utilization from Industry Sector to Metropolitan areasBehdad KIANI, Yoshinori HAMAMOTO, Atsushi AKISAWA, Takao KASHIWAGI2003 Volume 20 Issue 4 Pages 449-459
Published: 2003
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSThermally activated advanced absorption cycles are considered promising candidates to replace CFCs, HCFCs and HFCs for residential and commercial applications. In such absorption systems, it is desirable to utilize the waste heat from industries for heating and cooling applications in commercial and residential sectors. For this purpose, it is necessary to transport energy over some distance because the waste heat source and demand are generally located apart from each other. Transportation of steam, hot water or chilled water requires high construction costs for insulation. There is an efficient method of energy transportation using absorption system called “ Solution Transportation Absorption System (STA)”. The solution is transported at an ambient temperature so that tube-insulations not required. This paper shows the simulation of the abovementioned system and the optimal result, using mathematical optimization. The optimum system with industry′s waste heat utilization is obtained. At the end, the effect on the pollution emission and energy conservation is obtained.View full abstractDownload PDF (682K) -
1st Report : Triple Effect CycleNaoyuki INOUE, Tomoyoshi IRIE, Kiyoshi SAITO, Sunao KAWAI2003 Volume 20 Issue 4 Pages 461-472
Published: 2003
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSDouble effect chillers are commonly used as cooling machines for air condition. Great efforts have been making to improve the efficiency for a long time, and now the COP is very near to the limitation of double effect cycles. Triple effect cycles are expected for the next step beyond double effect cycles, but have some problems of high temperature and high pressure in the high stage generator. High temperature of absorbent causes corrosion problem and high vapor pressure over atmospheric pressure causes the restriction of legal regulation. This paper deals with many types of triple effect cycles. The temperature and dew point of the high stage generator are analyzed, several types are selected for low dew point, and one of them is more analyzed in detail.View full abstractDownload PDF (745K) -
2nd Report : Triple Effect Cycle with Auxiliary G/ANaoyuki INOUE, Kiyoshi SAITO, Sunao KAWAI2003 Volume 20 Issue 4 Pages 473-484
Published: 2003
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSTriple effect absorption refrigerating cycles are expected for the next step beyond double effect cycles , but have some problems of high temperature and high pressure in the high stage generator. High temperature of absorbent causes corrosion problem and high vapor pressure over atmospheric pressure causes restriction of legal regulation. This paper deals multi-effect absorption cycles which have better COP than double effect cycles and which have lower temperature and lower pressure than usual triple effect cycles.View full abstractDownload PDF (734K) -
Shin'ya OBARA2003 Volume 20 Issue 4 Pages 485-496
Published: 2003
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSThe chromosome model which simulates the operation patterns of energy system was introduced into simple genetic algorithm, and the method of dynamic optimization was developed. In this paper, the dynamic operation planning of the energy system which carries out combined use of solar power module, proton exchange membrane fuel cell co-generation with methanol steam reforming, geo-thermal heat pump, thermal storage and electric energy storage, commercial power, and the kerosene oil boiler was analyzed. From the calculation result of the developed analysis method, the hours of operation of each devices and the rate of the amount of output in the operational planning to devices were calculated, and the devices optimal capacity was examined. Furthermore, the characteristics of system operation planning under each objective functions were described.View full abstractDownload PDF (740K) -
Thien Nha TRAN, Yoshinori HAMAMOTO, Atsushi AKISAWA, Takao KASHIWAGI2003 Volume 20 Issue 4 Pages 497-508
Published: 2003
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSThe solar thermal driven desiccant dehumidification-absorption cooling hybrid system has superior advantage in hot-humid climate regions. The reasonable air processing of desiccant hybrid air conditioning system and the utility of clean and free energy make the system environment friendly and energy efficient. The study investigates the performance of the desiccant dehumidification air conditioning systems with solar thermal assistant. The investigation is performed for three cases which are combinations of solar thermal and absorption cooling systems with different heat supply temperature levels. Two solar thermal systems are used in the study: the flat plate collector (FPC) and the vacuum tube with compound parabolic concentrator (CPC). The single-effect and high energy efficient double-, triple-effect LiBr-water absorption cooling cycles are considered for cooling systems. COP of desiccant hybrid air conditioning systems are determined. The evaluation of these systems is subsequently performed. The single effect absorption cooling cycle combined with the flat plate collector solar system is found to be the most energy efficient air conditioning system.View full abstractDownload PDF (723K) -
2nd Report : Ice Melting CharacteristicsKenji Yoshimura, Shigeru KOYAMA, Toshihito FUKUDA, Hideki OHBA2003 Volume 20 Issue 4 Pages 509-516
Published: 2003
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSA system with a water -embedded-type ice storage vessel is widely used because of its simple structure compactness. However, this ice storage vessel has a disadvantage, that is, the melting rate is very small. The use of falling water film seems to be one of promising ways for solving this disadvantage. We have found in our previous study that the use of the falling water film is very effective, especially for high initial water temperatures. In the present study, we examined the melting performance of a falling-water-film-type ice thermal energy storage vessel with practical size, having vertical heat exchange plates. The results obtained are as follows : the quantity of melting ice increases with increase of the water film flow rate, the melting rate decreases with time because ice surface are decreases with time gradually, the heat transfer coefficient of melting increases with increase of the water film flow rate, and the melting rate increases with increase of the water-spray temperature.View full abstractDownload PDF (560K) -
Tetsuo HIRATA, Tadakazu INOUE, Masaaki ISHIKAWA2003 Volume 20 Issue 4 Pages 517-522
Published: 2003
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSExperimental studies for ice formation phenomena of water droplet fallen on a horizontal plate in a cold room have been performed.The ice formed in this method is so called ice stalagl11ite. Ethylene glycol aqueous solution of 2wt% is also tested for utilizing this ice forl11ation phenomenon for freeze concentration. It is found that the shape of formed ice is affected by cold room temperature as well as by water-droplet heat. The ice shape is classified into four groups, column, spiral, cone and cave-in. A transparent ice, where solute is highly excluded,is obtained under the condition that the cone-shaped ice is formed. The 2wt% ethylene glycol aqueous solution is successfully concentrated to 17-30wt% in the present experimental range, which implies the possibility of utilization of the present method for freeze concentration.View full abstractDownload PDF (695K) -
Yukihiro HIGASHI, Takeshi MIYAKE, Ken-ichi FUJII2003 Volume 20 Issue 4 Pages 523-530
Published: 2003
Released on J-STAGE: March 14, 2012
JOURNAL FREE ACCESSVapor-liquid equilibrium (VLE) data of the binary R32+R125 refrigerant mixture including R410A (50mass% R32 + 50mass% R125) were obtained by the circulation-type experimental apparatus with a liquid-bath thermostat. VLE measurements were carried out in the temperatures between 263.15 K and 318.15 K and in the pressures between 505 kPa and 2724 kPa. The experimental uncertainties of temperature, pressure, and composition measurements were estimated to be within 3 mK, 0.1 %, and 0.4 %, respectively. The present data were compared with reported experimental data against the REFPROP 6.01 as well as REFPROP 7.0 calculation results.View full abstractDownload PDF (454K)
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