1993 Fiscal Year Final Research Report Summary
A New Energy-saving Hybrid System Consisting of Latent Thermal Energy Storage and Flash Evaporation
| Project/Area Number |
03555200
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
化学工学
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
MIYATAKE Osamu Kyushu Univ., Faculty of Engng., Professor, 工学部, 教授 (70038579)
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| Co-Investigator(Kenkyū-buntansha) |
TOBIMATSU Hiroki Toto LTD., R & D Div., Research worker, 基礎研究所, 研究員
OMORI Hiromi Kyushu Univ., Faculty of Engng., Technical Official, 工学部, 教務員
NODA Hidehiko Kyushu Univ., Faculty of Engng., Research Associate, 工学部, 助手 (00112409)
FUKAI Jun Kyushu Univ., Faculty of Engng., Associate professor, 工学部, 助教授 (20189905)
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| Project Period (FY) |
1991 – 1993
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| Keywords | Energy conservation / Energy-saving system / Latent thermal energy storage / Flash evaporation / Hybrid system / Form-stable polyethylene / Spray flash evaporation / Evaporation efficiency |
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| Research Abstract |
An energy-saving hybrid system which consists of a latent thermal energy storage unit and a flash evaporation unit has been developed in order to generate the process steam by utilizing various sources of intermittent waste heat. We adopt form-stable polyethylene as a phase change material, and water as a heat transfer medium. The adaptation of this phase change material, which does not undergo melt flow even above the melting temperature, make it possible to perform the direct heat exchange with the heat transfer medium. The spray flash evaporation technique developed originally in our laboratory is applied to the flash evaporation unit. The heat transfer medium heated in the latent thermal energy storage unit is injected through a circular tube nozzle into the flash evaporation unit, where a portion of it flashes off as vapor.
The discharge characteristics of the latent thermal energy storage unit, the evaporation efficiency of the flash evaporation unit, and the over-all thermal efficiency of the hybrid system are experimentally examined. As a result, the system is found to generate the process steam relevant to the heat quantity more than 95% of the stored thermal energy, even in the case of lower superheats, due to the high efficiency of the spray flash evaporation technique. The result suggests that out hybrid system can be applied to energy-saving systems.
In addition, semi-empirical equations for predicting the time variation of the temperature and the evaporation rate of the heat transfer medium are deduced as the function of various operating parameters. These results make it possible to simulate the time variation of the amount of steam generated.
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