Study on Compact Absorber and Evaporator using finned wall

翅片壁紧凑型吸收器和蒸发器的研究

• 批准号: 14580534
• 负责人: NAGASAKI Takao
• 金额: $ 2.24万
• 依托单位: TOKYO INSTITUTE OF TECHNOLOGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14580534/
• 关键词: Absorption Heat Pump; Absorber; Evaporator; LiBr; 臭化リチウム水溶液; 微細フィン

A compact absorber combined with evaporator was proposed for absorption heat pumps. Both the absorber and evaporator are vertical plates, along which liquid films fall down, and they are integrated into one unit by arranging the evaporator plate and absorber plate one by one alternatively. In order to enhance the absorption of water vapor into a falling liquid film of LiBr/water solution along the vertical plate, the effect of offset fins on the wall was investigated. The absorption rate was measured for various liquid flow rates and compared with that for a smooth wall. It was experimentally found that the absorption rate for the finned wall is especially large under the condition of small liquid flow rate and is about three times larger than that for a smooth wall. The enhancement is also predicted by a numerical analysis although the experimental absorption rate is larger than the numerical results. The enhancement of evaporation on a vertical plate was also investigated by using a wall with mesh screen soldered on it. It was shown that the wall mesh has a high evaporation performance due to the capillary and fin effects, and an optimum mesh size was determined experimentally.

提出了一种用于吸收式热泵的紧凑型吸收器与蒸发器相结合的结构。吸收器和蒸发器均为垂直板，液膜沿垂直板下落，通过蒸发器板和吸收器板依次交替布置而成一体。为了增强LiBr/水溶液沿垂直板下落的液膜对水蒸气的吸收，研究了偏置翅片对壁面的影响。测定了不同液体流速下的吸收率，并与光滑壁面的吸收率进行了比较。实验发现，在液体流速较小的情况下，翅片壁面的吸收率特别大，约为光滑壁面吸收率的3倍。虽然实验吸收率大于数值结果，但数值分析也预测了这种增强。还研究了在垂直板上焊有筛网的壁面对蒸发的促进作用。结果表明，由于毛细管效应和翅片效应的影响，壁式滤网具有较高的蒸发性能，并通过实验确定了最佳滤网尺寸。

项目成果

Nagasaki, T., Okuyama, T., Ito, Y.: "Enhancement of Water Vapor Absorption into LiBr/H2O Film by Offset Fins"Proc.40^<th> National Heat Transfer Symposium of Japan. Vol.II. 571-572 (2003)

Nagasaki, T.、Okuyama, T.、Ito, Y.：“通过偏移翅片增强 LiBr/H2O 薄膜中的水蒸气吸收”Proc.40^<th> 日本全国传热研讨会。

長崎孝夫: "オフセットフィンによるLiBr水溶液への水蒸気吸収促進"第40回日本伝熱シンポジウム講演論文集. II. 571-572 (2003)

Takao Nagasaki：“通过偏置翅片促进溴化锂水溶液中的水蒸气吸收”第 40 届日本传热研讨会 II 571-572 论文集。

長崎, 奥山, 伊藤: "オフセットフィンによるLiBr水溶液への水蒸気吸収促進"第40回日本伝熱シンポジウム講演論文集. (発表予定). (2003)

Nagasaki, Okuyama, Ito：“通过偏置翅片促进溴化锂水溶液中的水蒸气吸收”第 40 届日本传热研讨会论文集（预定报告）（2003 年）。