Working-fluid selection for minimized thermal resistance in ultra-thin vapor chambers

TLDR: In this paper, a resistance-network-based model is used to develop a simple analytical relationship for the vapor chamber thermal resistance as a function of the working fluid properties, operating power, and geometry.

About: This article is published in International Journal of Heat and Mass Transfer.The article was published on 2017-03-01 and is currently open access. It has received 38 citations till now. The article focuses on the topics: Working fluid & Compressed fluid.

Figures

Figure 3. Schematic diagram of the operation of a vapor chamber.

Figure 4. Contours of effective vapor core conductance as a function of the liquid and vapor figures of merit for operating powers of (a) 0.25 W, (b) 1 W, and (c) 3 W. R = 45 mm, Re = 5 mm, t = 100 µm, n = 3, Fs = 2; the wick is sintered copper (m = 0.21, f = 150) with 60% porosity; thermophysical properties evaluated at 325 K.

Figure 5. Plots showing the best working fluids in the power-working thickness space. Properties are calculated at (a) Tv = 325 K, (b) Tv = 350 K, and (c) Tv = 375 K. R = 45 mm, Re = 5 mm, n = 3, Fs = 2; the wick is sintered copper (m = 0.21, f = 150) with 60% porosity.

Table 1. Fluid property figures of merit for six fluids at Tv = 325 K.

Frequently asked questions

Q1. What have the authors contributed in "Working-fluid selection for minimized thermal resistance in ultra-thin vapor chambers" ?

A working fluid is sought in this case that provides the minimal thermal resistance while ensuring a capillary limit is not reached at the target operating power.