Research on utilization of high-performance heat transport device

1998 Fiscal Year Final Research Report Summary

• Project/Area Number: 09555069
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 展開研究
• Research Field: Thermal engineering
• Research Institution: The University of Tokyo
• Principal Investigator: NISHIO Shigefumi The University of Tokyo, Institute of industrial science, Prof., 生産技術研究所, 教授 (00111568)
• Co-Investigator(Kenkyū-buntansha): SHIRAKASHI Ryo The University of Tokyo, Institute of industrial science, Lecturer, 生産技術研究所, 講師 (80292754)
• Project Period (FY): 1997 – 1998
• Keywords: Heat Transport Tube / Dream Pipe / Oscillatory Flow / Heat Pipe / Bubble / Condensation / Evaporation / utilization

Research Abstract

Oscillation-controlled heat transfer device(OC-HTD)is a promising alternative to gravity-driven heat transfer devices or capillary-driven heat transfer devices. When cooling of electronic devices is considered as an application of OC-HTD, two types of HTDs are necessary to be developed, in order to popularize OC-HTD :
(C) Forced oscillation controlled HTD(FOC-HTD), including a compact oscillation inducing mechanism
(D) Self-excited oscillation controlled HTD, with no oscillation inducing mechanism
In this research, these two kinds of HTDs are experimentally manufactured and analyzed, and the following results were obtained.
[3] A phase-shifted oscillation controlled HTD with external miniature motor as oscillation-inducing mechanism, was successfully manufactured and operated. The effective thermal conductivity of this HTD was in good agreement with the result of theoretical analysis, reported earlier. The transient performance of this HTD was experimentally found good.
[4] A bubble driven HTD consisted with 12-turn closed loop was manufactured and operated, and some operating conditions inducing self-excited oscillation was found. By utilizing this self-excited oscillation, the OC-HTD with no mechanism for inducing oscillation can be made. The stability of operation of this HTD was experimentally investigated. With constant tube inner diameter and temperature difference and liquid volume fraction, wider range of stable operating condition could be obtained by using working fluids with shorter capillary length. The possibility of simulating vapor plug propagation phenomenon, by homogeneous flow model, was indicated.
[5] An integrated type of FOC-HTD, with build-in diaphragm actuator was successfully manufactured and operated. The effective thermal conductivity of this HTD was in good agreement with theoretical analysis reported earlier.