Transactions of the Society of Heating,Air-conditioning and Sanitary Engineers of Japan
Online ISSN : 2424-0486
Print ISSN : 0385-275X
ISSN-L : 0385-275X
Volume 22, Issue 67
Displaying 1-20 of 20 articles from this issue
  • Article type: Cover
    1997 Volume 22 Issue 67 Pages Cover1-
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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  • Article type: Cover
    1997 Volume 22 Issue 67 Pages Cover2-
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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  • Article type: Appendix
    1997 Volume 22 Issue 67 Pages App1-
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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  • Article type: Index
    1997 Volume 22 Issue 67 Pages Toc1-
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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  • Article type: Appendix
    1997 Volume 22 Issue 67 Pages App2-
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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  • Article type: Appendix
    1997 Volume 22 Issue 67 Pages App3-
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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  • Yoshiyuki SHIMODA, Toshinari MOMOSE, Minoru MIZUNO, Takayuki KANAJI, S ...
    Article type: Article
    1997 Volume 22 Issue 67 Pages 1-11
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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    In the previous paper, the authors estimated the amount of energy which can be recovered as a heat source and heat sink of heat pumps from river water, sea water and treated sewage water in the Osaka city area. This result showed that the total amount of usable heat is abundant, however, the actual usable amount of heat would be restricted to only 0〜30% of the total since spatial discrepancy between heat sources and heat demand is large. In this paper, the transportation networks of these water is proposed as a measure for positive utilization. In the network, a DHC system is assumed in each mesh (250m square) and heat source water is supplied to the DHC plants from the heat source in order of the energy saving potential. The energy saving characteristics of the transportation networks is evaluated by numerical simulation. The actual amount of energy saved is calculated by considering the energy consumption for the transportation of heat source water. The results are summarized as follows: (1) The actual amount of heat is increased dramatically by the transportation networks. The networks can cover 40% of total heat demand in Osaka city area and the primary energy saving potential is estimated at 3581TJ/a. (2) By unifying pipeline for several DHC plants commonly, the energy saving potential is increased by 30%. (3) Spatial relationship between heat source and heat demand is also important in the case of using transport networks. By this reason, energy saving potential of sea water and treated sewage water in the Osaka city area is not improved well as river water. (4) Transportation networks also has a large heat island prevention effect. (5) The embodied CO_2 emission in pipelines and pumps is equal to 1.3 times of the amount of CO_2 emission decreased by energy saving during a year. (6) As the COP of heat pump is increased as shown in Fig.11, the energy saving potential is increased by 40%.
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  • Shigeki KAMETANI, Minoru MIZUNO, Yoshiyuki SHIMODA
    Article type: Article
    1997 Volume 22 Issue 67 Pages 13-21
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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    Data base of air-conditioning systems used in Japan was prepared to examine the influence of air-conditioning waste heat given on urban thermal environment. By using this data base, the time series transition of heat source equipment, heat discharge methods, and equipment capacities etc. was discussed. Moreover, the amount of waste heat from air conditioning systems in Osaka city area was estimated about 1977, 1985 and 1993 respectively and the distribution of sensible waste heat was also estimated.
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  • Masatake IRIBE, Yuji RYU, Toshiyuki WATANABE, Yasunori AKASHI
    Article type: Article
    1997 Volume 22 Issue 67 Pages 23-31
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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    The purpose of this study is to settle the problem of "cooling-heating-electrical load" among many problems of district energy systems. In this study, we establish the load prediction method by estimate and analysis. This paper outlines the running states of the DHC & CGS plants, compares the thermal load unit generally employed at planning/designing stage and the actual cooling load, and analyzes the relationship between the thermal load by time, which is useful in predicting cooling load, and the meteorological factor. Consequently, the analysis shows that cooling load of peak by day and time are forecasted accurately by the discomfort index of peak on the day and the time. It also proves that the cooling load can be estimated more precisely in the case taking the cooling load of an area as an object than that taking the cooling load of individual facilities.
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  • Masao MASUDA, Toshio HAYASHI, Yoshiyuki KOZAWA
    Article type: Article
    1997 Volume 22 Issue 67 Pages 33-43
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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    Both theoretical and experimental studies on the VAV air conditioning system by using conventional motor-dampers have been performed to obtain an alternative as far the air handling having both of individuality and saving energy. By adjusting the static pressure in a main duct system under the cascade-control and by keeping the damper degree up a certain value by referring to the static pressure signal, the mutual interference among motor-dampers installed in the system can not only be eliminated, but also the minimum value of the ventilation be maintained. For the case of introducing this proposed VAV system to a general office building whose air conditioning area per a unit system is about 500m^2, the control parameters have been determined. These parameters are applicable in the wide range of actual usage, and moreover the troublesome adjustments of the parameters under construction in a real field can be avoided. From the comparative studies on the system performances, it have been confirmed that the controllability and the energy saving of the proposed VAV system are nearly equivalent to those of a usual VAV system.
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  • Kazuaki BOGAKI, Mitsuo KADOYA, Etsuro ARIKAWA, Hiroshi MIYAGI, Kanta F ...
    Article type: Article
    1997 Volume 22 Issue 67 Pages 45-56
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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    The Passive Rhythming Air Conditioning System is a proposal for new energy conservation method in the field of HVAC technologies. This system makes passive temperature change once or twice an hour stopping the air conditioning equipment in a few minutes. Stopping air conditioning equipment is one of the most effective energy conservation method. However, the most important issue of this method is to make clear the influence of temperature change on thermal comfort and the working effeciency. This paper describes the results of subjective experiments on the effects of passive temperature change on thermal comfort. The main results are as follows; 1) There is no difference on thermal comfort between the Passive Rhythming Air Conditioning System and ordinary (constant temperature control) system in case of 24℃ of base temperature. 2) Adding clothes to females, thermal and comfort sensation were improved. It can be suggested that there is a good possibility of application of this system to real buildings having on appropriate clothes. 3) Recently, the cooling load in winter is increasing at office buildings. Examining the effects of passive temperature change in the cooling mode, it is found that the passive temperature change in that case should also be accepted.
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  • Masaki IMAI, Seishi OKADA, Nobuo MUTO
    Article type: Article
    1997 Volume 22 Issue 67 Pages 57-65
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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    Wastewater reuse, whose main purpose is to take appropriate measures for water saving such as recyclic use of water and practical utilization of wastewater in order to help preserve the water resources of the earth, and which can be used as a water recycling system, was specifically developed and put to practical use to respond to an increasing rise in demand for water principally in the center of the large cities in Japan. In this research we deal with slime problems which are responsible for a sharp reduction in the amount of flow through distributing pipes, the clogging of those pipes, the greatly reduced efficiency of heat exchangers or regenerators and an increase in local corrosion resulting from the depositing of slime on the internal surface of the pipes. In view of water quality, let us then consider the subject in detail. A series of experiments are carried out to find an effective way of preventing formation of the slime with a particular emphasis on a major factor in slime formation and on the form of the slime in relation to the quality of the recycled water. The results of the research can be summarized as follows: 1) Where raw effluent and artificial sewage are used in slime formation in pipes, each of the water samples treated by coagulation and sand filtration can be reduced to 30% and 10% of the slime volume respectively; 2) The presence of a chemical compound made of nitrogen (N) or phosphorus (P) as a nutrient in water has a profound influence on the formation of slime. In particular, the presence of P is a main factor in slime formation; 3) Formation of the slime has turned out to change over time in the form of first-order reaction; 4) The composition of this slime is expressed in Chemical Formula C_7H_<12>NO_6. The composition of the slime is similar to that of one of the bacteria as a living organism. Support for the above argument can also be found from the biological activity resulting from oxygen consumption by that organism.
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  • Yoshiyuki KAMIYA, Shigeru KURIHARA
    Article type: Article
    1997 Volume 22 Issue 67 Pages 67-74
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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    Recently a heat storage tank using spherical ice storage capsules has been used because of high heat transfer rate and high density of stored heat. In order to design the ice storage tank of this type optimally and to operate it effectively, it is necessary to predict its charging and discharging characteristics with high accuracy. For the sake of this achievement, it is also necessary to investigate the model that reveals phase changing phenomena accurately to estimate heat transfer characteristics of a spherical ice storage capsule. In this paper, freezing processes inside the spherical capsule were visualized and measurements of its freezing rate were conducted. A freezing model considering the volume change caused by phase changing and inside air room to absolve it was proposed. Coefficient of Heat transfer rates calculated from the proposed model were compared with that measured. Good agreements were obtained between measured and calculated results. Furthermore the proposed model was compared with conventional ones. It was found that, at beginning of freezing, calculated heat transfer rates from conventional models are more than 20% higher than that from the proposed one.
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  • Yu LIU, Kenji HIRAOKA
    Article type: Article
    1997 Volume 22 Issue 67 Pages 75-84
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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    In a room with a raised floor HVAC system (RF system), the vertical temperature gradient became an important factor in relation to the ventilation requirement to maintain a vertical temperature difference within a comfort standard such as ASHRAE Standard 55-1992. A series of detailed laboratory experiments were carried out to obtain the design ventilation requirements with various conditions of ventilation rates, cooling loads, and types of floor outlets. The main results are shown as follows. (1) From measurements it is clear that the vertical temperature gradient is strongly dependent on the throw contributed to supply air volume, cooling load and type of floor outlet. (2) The relationship between the vertical temperature difference in an occupied zone and the ratio of internal loads to ventilation rates was obtained, and the design ventilation requirements for the RF system were recommended.
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  • Naoko NAKAGAWA, Tamotsu TAKAYANAGI, Katsunori FURUHATA, Fumitoshi KIYA
    Article type: Article
    1997 Volume 22 Issue 67 Pages 85-94
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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    Hot water supply systems have been popularized for wider application ranges in Japan. However, they have water quality problems caused by temperature change. In the previous report, from the result of the survey about hot water quality to suggest guidelines for keeping sanitary conditions, the deterioration of water quality was found in particularly central hot water supply systems, in which hot water temperature tends to be lower and the detention time in pipe tends to be longer. In this study, the authors considered the bacteria multiplying area in the pipe and its environmental characteristics. And further, the temperature change in the system, supposed to influence on hot water quality significantly, was considered through the measurement survey and the forecasting. At last the point of design and maintenance for keeping sanitary condition was suggested.
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  • Article type: Bibliography
    1997 Volume 22 Issue 67 Pages 95-112
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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  • Article type: Appendix
    1997 Volume 22 Issue 67 Pages App4-
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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  • Article type: Appendix
    1997 Volume 22 Issue 67 Pages App5-
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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  • Article type: Appendix
    1997 Volume 22 Issue 67 Pages App6-
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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  • Article type: Cover
    1997 Volume 22 Issue 67 Pages Cover3-
    Published: October 25, 1997
    Released on J-STAGE: September 05, 2017
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