-Present Data
CONCLUDING REMARKS
In this study experimental tests are conducted to investigate an improved CPL design for high power density CPU cooling through covering a thin cotton gauze layer on the vertical and bottom walls of the grooved channels for vapor flow to provide more surface area for liquid vaporization. The effects of the liquid inventory, cooling water temperature in the condenser, and relative height between the condenser and evaporator, and cotton gauze layer covering on the heat transfer performance of the CPL have been examined in detail. The major results obtained here can be briefly summarized as follows:
(1) An optimal liquid inventory exists at which Qe,max is the highest and Rth is the lowest for given Tcold and relative condenser-evaporator height for the CPL with and without cotton gauze layer covering on the side and bottom walls of the grooved channel. Moreover, increasing or decreasing the liquid inventory from this optimal value causes a reduction in Qe,max and a raise in Rth.
(2) The CPL heat transfer capability is only slightly affected by the cooling water temperature in the condenser. But the evaporator temperature is noticeably higher for a higher Tcold.
(3) An increase in the relative height between the condenser and evaporator results in a significant improvement in the CPL performance with a much higher Qe,max and a much lower Rth. Besides, for a larger relative condenser-evaporator height the influences of the liquid inventory on the performance of the CPL are milder.
(4) Covering a thin cotton gauze layer on the vertical and bottom walls of the grooved channels can substantially improve the heat transfer performance of the CPL
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system under certain conditions. For other conditions the improvement is comparatively smaller.
(5) Empirical correlations for Qe,max and Rth,min are proposed for the present CPL system to facilitate thermal design of CPU cooling units.
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