Miniature heat pipes

Experimental samples of the fiat miniature heat pipe were chosen as copper /water heat pipe with three types of a wick sintered powder wick, wire mesh wick and wire bundle wick (Figure 10). The experimental data of qmax, Qmax, Rhp, he and he as a function of heat pipe tilt were obtained for different heat load and heat pipe orientation in space and temperature level. 

Optimisation of copper sintered powder wick in miniature copper/water heat pipes with outer diameter 4 mm and length 200 mm is a good challenge to improve the mHP parameters. Analysis of the experimental data for such a new optimised miniature heat pipe with copper sintered powder wick proves the possibility to use mHPs independently of its orientation with the maximum heat transport capability near 50 W. 

Vasiliev L.L., (1993), Open - type miniature heat pipes. Journal of Engineering Physics and Thermophysics, Vol.65,No. 1, 625 - 63f... 

Hopkins R., Faghri A., Khrustalev D., (1999), Flat miniature heat pipes with micro capillary grooves. Journal of heat transfer, Vol.121,102 - 109... 

Kim S.J., Seo J.K., Do K.H., (2003), Analytical and experimental investigation on the operational characteristics and the thermal optimization ob a miniature heat pipe with a grooved wick structure, International Journal of heat and Mass Transfer, Vol.46, 2051 - 2063... 

Oh Se Min, (2002), Miniature Heat Pipes Experimental Analysis and Software Development, Proceedings of the 12 International Heat Pipe Conference, Moscow, 329 — 335. 

Vasiliev, L.L., Maziuk, V.V., Kulakov, A.G., Rabetsky, M.I., (2000), Miniature heat pipes software development and experimental verification. Proceedings of the IV Minsk International Seminar Heat pipes, Heat pumps, Refrigerators , September 4-7, Minsk, Belarus, pp. 270-278. 

Fig. 8 Wetting characteristics effect on the heat transport capability in a miniature heat pipe...

Since Peterson [4] developed the first real micro heat pipe, a wide variety of micro/miniature heat pipes have been developed and utilized in microelectronic systems or components. Figure 11 illustrates an array of micro heat pipe application in an electronic component cooling. In order to reduce the vapor flow effect, increase the... 

Micro Heat Pipes, Fig. 12 Miniature heat pipes in a laptop computer cooling... 

Moon, S.H. et al. (2004). Improving thermal performance of miniature heat pipe for notebook PC cooling. Microelectronics Reliability, Vol. 44, pp. 315-321. 

Vapor Flow Effect For a relatively large conventional heat pipe, the wick structures existing in the heat pipe help to reduce the vapor flow effect on the liquid flow. For a micro/miniature heat pipe, the vapor space in the micro heat pipe is so small and the ratio of the hydraulic diameter of the vapor flow channel to the hydraulic diameter of liquid flow in the comer regions is much larger than a conventional heat pipe. The vapor flow has a larger effect on the heat transport capability than the conventional heat pipe. Ma et al. [5] have conducted a detailed investigation of the vapor flow effect on the liquid flow. The friction coefficient Reynolds number product, i. e., Cfj Rei, for the liquid flow in the comer region must include the vapor flow effect, which depends on the vapor flow rate. 

Micro Heat Pipes, Hgure 10 Miniature heat pipes In a laptop computer... 

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