A HEAT TRANSFER TEXTBOOK - THIRD EDITION Episode 1 Part 7 pot

... 627 11 .6 Mass transfer at low rates 635 11 .7 Steady mass transfer with counterdiffusion 648 11 .8 Mass transfer coefficients at high rates of mass transfer . 654 11 .9 Simultaneous heat and mass transfer ... the right pass x Contents IV Thermal Radiation Heat Transfer 523 10 Radiative heat transfer 525 10 .1 The problem of radiative exchange 525 10 .2 Kirchhoff’s la...

Ngày tải lên: 07/08/2014, 10:20

... parallel, black, opaque plates transfer heat by radiation, as shown in Fig. 1. 18. Find T 2 . 1. 15 Four infinite, parallel, black, opaque plates transfer heat by radiation, as shown in Fig. 1. 19. ... electrical resistance heater, releasing 10 00 W/m 2 . Calculate (a) the heater temperature, (b) the heat transfer from the methanol to the heater, and (c) the heat transfer f...

Ngày tải lên: 07/08/2014, 10:20

... with weather data to estimate heating and cooling loads [2.5]. 78 Heat conduction, thermal resistance, and the overall heat transfer coecient Đ2 .4 transfer coecient h e = h + h rad = 18 .44 W/m 2 K. ... = ∆T R t total = T ∞ 1 −T ∞ r 1 hA + 1  k p A p L + k s A s L  + 1 hA and U = Q A T = 1 2 h + 1  k p L A p A + k s L A s A  The approach illustrated in...

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... with, we take U to be a constant value. This is fairly reasonable in compact single-phase heat exchangers. In larger exchangers, particu- larly in shell-and-tube configurations and large condensers, ... conguration. Figure 3 .5 shows the U-tubes of a two-tube-pass, one-shell-pass exchanger being installed in the 99 Figure 3 .5 Typical commercial one-shell-pass, two-tube-pass heat ex...

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... multipass shell- and-tube heat exchangers and one-pass cross-flow exchangers. 11 9 a. F for a one-shell-pass, four, six-, tube-pass exchanger. b. F for a two-shell-pass, four or more tube-pass exchanger. Figure ... (Data provided by A. D. Krauss.) 12 4 Problems 13 1 3 .13 Air at 2 kg/s and 27 ◦ C and a stream of water at 1. 5 kg/s and 60 ◦ C each enter a heat exchanger. E...

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... 0 (4.9) 16 0 Analysis of heat conduction and some steady one-dimensional problems §4.4 Figure 4.5 Heat conduction through a heat- generating slab with asymmetric boundary conditions. Example 4 .7 A slab ... gravitational forces. Fr is about 10 00 for a pitched baseball, and it is between 1 and 10 for the water flowing over the spillway of a dam. 4 One can always divide any...

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... section. 18 2 17 8 Analysis of heat conduction and some steady one-dimensional problems §4.5 where R t fin = 1  kAhP tanh mL for a straight fin (4. 58) In general, for a fin of any shape, fin thermal resistance ... It hasa2cmO.D. and a 1. 88 cm I.D. The material is type 304 stainless steel. Assume that the fluid is steam at 260 ◦ C and that the heat transfer coefficient betwe...

Ngày tải lên: 07/08/2014, 10:20

... briefly at the dimensional analysis of transient con- duction in general and of lumped-capacity systems in particular. Dimensional analysis of transient heat conduction We first consider a fairly ... t/T can be viewed as t T = hk(V /A) t ρc(V /A) 2 k = h(V /A) k · αt (V /A) 2 = Bi Fo (5.7) Electrical and mechanical analogies to the lumped-thermal-capacity problem The term capacitance is...

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... 0.7 910 3 1. 1 016 0.9903 1. 14897 1. 1724 0.9893 1. 43203 1. 2236 0.9904 0.90 0.82740 1. 110 7 0.9882 1. 20484 1. 1902 0.9869 1. 50442 1. 2488 0.9880 1. 00 0.86033 1. 119 1 0.98 61 1.25578 1. 20 71 0.9843 1. 57080 1. 2732 ... 0.94077 1. 114 3 0.9954 1. 16556 1. 14 41 0.9960 0.60 0.70507 1. 0 814 0.9940 1. 018 44 1. 1345 0.9936 1. 26440 1. 1 713 0.9944 0.70 0.75056...

Ngày tải lên: 07/08/2014, 10:20

...  = 3 20 φ− 3 28 0 φ 3    = 3 2u ∞ (6. 52) Since φ is a constant for any Pr [recall eqn. (6.46)], we separate variables: 2 t dδ t dx = dδ 2 t dx = 3 /u ∞  3 20 φ − 3 28 0 φ 3  §6.5 Heat transfer ... 0.0 021 35 so τ yx = (0.0 021 35 ) 1 2 ρu 2 ∞ = (0.0 021 35 )(1.05)(15) 2 2 = 0 .25 22 kg/m·s 2 and the force is τ yx A = 0 .25 22( 0.5) 2 =...

Ngày tải lên: 07/08/2014, 10:20

... Int. J. Heat Mass Transfer, 13: 1 425 –1 439 , 1970. [9. 23 ] J. S. Ded and J. H. Lienhard. The peak pool boiling heat flux from a sphere. AIChE J., 18 (2) :33 7 34 2, 19 72. [9 .24 ] A. L. Bromley. Heat transfer ... correlation for saturated two-phase flow boiling heat transfer inside horizontal and vertical tubes. J. Heat Transfer, 1 12( 1) :21 9 22 8, 1990. §10 .3 Radi...

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... The geometrical mean beam length is defined as L 0 ≡ 4 (volume of gas) boundary area that is irradiated (10. 54) Thus, for two infinite parallel plates a distance  apart, L 0 = 4A / 2A = 2. Some other values ... net heat transfer is calculated using the surface area of the wall: Q net g-w = A w g T 4 g g T 4 w = (0 .4) (5.67 ì 10 8 ) (0.098)( 14 73) 4 (0.12)(5 73) 4...

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... 1.42ì10 5 air-ethanol 31 3 1. 45 air-helium 276 6.24 air-napthalene 30 3 0.86 air-water 31 3 2.88 argon-helium 2 95 8 .3 628 32 .1 1068 81.0 (dilute solute, 1 )-( liquid solvent, 2) T (K) D 12 (m 2 /s) ethanol-benzene ... D 12 (m 2 /s) ethanol-benzene 288 2. 25 10 9 benzene-ethanol 298 1.81 water-ethanol 298 1.24 carbon dioxide-water 298 2.00 ethanol-water 288 1.00 methane-water 2...

Ngày tải lên: 07/08/2014, 10:20