Heat Pipe with High Heat Transfer Rate by Reciprocating Motion (Examination of Application to Automotive Engine Piston)
往復動による高伝熱可能なヒートパイプ（自動車用エンジンピストン適用検討）
- Delivery
- Available on the other site
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- Paper/Info type
- Honda R&D Technical Review
Vol.33 No.1
- Pages
- 57-65(Total 9 p)
- Date of publication
- Mar 2021
- Publisher
- Others, Unknown
- Language
- Japanese
Detailed Information
| Category(J) | 論文 Translation |
|---|---|
| Category(E) | Technical Papers and Explanation |
| Author(J) | 1) 松本 謙司 |
| Author(E) | 1) Kenji MATSUMOTO |
| Affiliation(J) | 1) 本田技術研究所 |
| Affiliation(E) | 1) Honda R&D |
| Abstract(J) | 一般にヒートパイプは振動や傾斜等によって，気液の流れが阻害され，極端に熱伝導率が低下するため，自動車やオートバイ等で使用されている事例がない． そこで，我々は配管内部の摩擦エネルギー損失を変え，自励振動を強制的におこなう事によって気液二相の流れを制御し，熱輸送量を低下させない新たなヒートパイプを提案した． 往復動による振動を与え，熱伝達率を計測した結果，静止状態の熱伝達率に比べ1.6倍の熱伝達率を示す事が明らかとなった．そのメカニズムは，ヒートパイプ中に密封した液体が，初期の段階で往復により細かな液滴に分解する．その後，この液滴の状態で，ゲートとの接触しながら巨視的に一定の方向の駆動力を得て流れが一方向になる．更にループする事で気液が衝突する事がなく，凝縮領域から蒸発領域への気液の移動を可能にしたと考えている． 今回はエンジンピストンに適用した場合の熱解析を実施し，ピストンヘッド中央温度を39 K下げる事ができ，⊿Tも140 Kから75 Kまで低下させる事ができたため，サーマルストレス低減効果が期待される． Translation |
| Abstract(E) | The flow of gas and liquid in heat pipes is generally impaired by factors such as oscillation and inclination, with the result that the heat transfer becomes excessively low. For this reason, there are no known cases of heat pipe use in cars and motorcycles, etc. The authors, therefore, proposed a new heat pipe that controls the two-phase flow of gas and liquid without reducing the amount of heat transport, by reducing the friction energy loss inside the pipe and forcibly inducing self-oscillation. Measurement results in the condition with oscillation applied by reciprocating motion showed an increase in the heat transfer coefficient by a factor of 1.6 compared with that at standstill. That mechanism is thought to be as follows. In the initial stage, the liquid sealed in the heat pipe is broken up into fine droplets by reciprocation. The droplets then acquire drive force in a constant direction macroscopically while contacting the gates, producing a unidirectional flow. Further, a loop flow channel enables transfer of gas and liquid from condensed areas to evaporation areas without gas-liquid collision. This study performed thermal analysis of the case when applied to an engine piston. The results showed that the temperature at the piston head center was reduced by 39 K and DT was also reduced from 140 K to 75 K, and thus thermal stress reduction effects can be anticipated. |
