A HEAT TRANSFER TEXTBOOK - THIRD EDITION Episode 1 Part 4 potx

... 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...

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... 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

... [5.6] 13 . Isothermal ellipsoid of semimajor axis b and semiminor axes a conducts heat into an infinite medium at T ∞ ; b> ;a( see 4) 4πb  1 a 2  b 2 tanh 1   1 a 2  b 2  meter [5 .16 ] 24 6 26 2 ... 5 .1 0a Φ 1 ( Fo 1 = 0.565, Bi 1 = 0 . 21 05 ) = 0 .10 Φ 2 ( Fo 2 = 0.565, Bi 2 = 0 . 21 05 ) = 0 .10 and, with eqn. (5.7 3a) , Φ = Φ 1 +Φ 2 (...

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... transitional value. Problems 335 6.31 A thin metal sheet separates air at 44 ◦ C, flowing at 48 m/s, from water at 4 ◦ C, flowing at 0.2m/s. Both fluids start at a leading edge and move in the same ... at 25 ◦ C flows at 0.7m/s over a 4 cm-long flat heater at 60 ◦ C. Find h, τ w , h(x = 0. 04 m), and δ(x = 0. 04 m). 6 .20 A large plate is at rest in water at 15 ◦ C. The plate i...

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... R -1 2 5 1. 10 R -1 2 1. 50 R- 13 4a 1. 63 R-22 2.20 R -1 5 2a 1. 10 R -3 2 1. 20 R- 41 0a 1. 72 so that h fb h lo = fn ( Bo, Co ) (9.49) When the convection number is large (Co  1) , as for low quality, nucleate boiling ... 30 5.6kg/m 2 s and Re lo = GD à f = (30 5.6)(0.05) 1. 297 × 10 −4 = 1. 178 × 10 5 From eqns. (7.42) and (7. 43) : f = 1  1. 82 log 10 (1. 178...

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...

Ngày tải lên: 07/08/2014, 10:20