fundamentals of heat and mass transfer solutions manual phần 7 pot

... per unit length of the tube; effect on quality, x, at outlet of 30 m length of tube; (b) Effect of radiation on heat transfer and quality of outlet flow; (c) Effect of emissivity and insulation ... PROBLEM 9 .78 (Cont.) (b,c) Summary of the calculations above and for water and ethylene glycol: Fluid Ra D ( ) 2 D hW/mK ⋅ q(W) Air 6 .75 0 × 10 4 10.6 1.55 < Water...

Ngày tải lên: 08/08/2014, 17:20

... value of the heat rate. PROBLEM 1.39 KNOWN: Power consumption, diameter, and inlet and discharge temperatures of a hair dryer. FIND: (a) Volumetric flow rate and discharge velocity of heated ... ANALYSIS: Heat transfer from the case must balance heat dissipation in the transmission, which may be expressed as q = P i – P o = P i (1 - η ) = 150 hp × 74 6...

Ngày tải lên: 08/08/2014, 17:20

... Temperature and volume of hot water heater. Nature of heater insulating material. Ambient air temperature and convection coefficient. Unit cost of electric power. FIND: Heater dimensions and insulation ... radius. PROBLEM 3.43 KNOWN: Diameter of electrical wire. Thickness and thermal conductivity of rubberized sheath. Contact resistance between sheath and wire. Convectio...

Ngày tải lên: 08/08/2014, 17:20

... 198.2 193.3 186 .7 178 .3 168.4 1 57. 4 145.6 133.4 121.0 50 228.9 228.3 226.2 222.6 2 17. 2 209 .7 200.1 188.4 175 .4 161.6 1 47. 5 75 255.0 254.4 252.4 248 .7 243.1 235.0 223.9 209.8 194.1 177 .8 100 282.4 ... below, where x and y are in mm and the temperatures are in ° C. y\x 0 25 50 75 100 125 150 175 200 225 250 275 300 0 180 .7 180.2 178 .4 175 .4 171 .1 165.3 158.1 149.6 140...

Ngày tải lên: 08/08/2014, 17:20

... 68.8 52.5 20 3 85 76 .9 68.8 44.4 20 4 20 76 .9 76 .9 60 .7 44.4 20 5 76 .9 68.8 60 .7 40.4 20 6 30 68.8 68.8 54.6 40.4 20 7 68.8 61 .7 54.6 37. 3 20 8 40 61 .7 61 .7 49.5 37. 3 20 9 45 61 .7 55.6 49.5 34.8 ... 294 .7 313 .7 320.3 324.5 325 325 325 325 4 72 293.0 3 07. 8 318.9 322.5 324.5 325 325 325 5 90 2 87. 6 305.8 315.2 321.5 323.5 324.5 325 325 6 108 285.6 301.6 313.5...

Ngày tải lên: 08/08/2014, 17:20

... plate and ( ) ( ) () 4/5 1/3 4/5 1/3 5 L L Nu 0.037Re 871 Pr 0.0 37 9 .78 10 871 0 .70 1263  =−=×− =   2 L k 0.028W m K h Nu 1263 29.7W m K L 1.2m ⋅ == = ⋅ The heat rate is ()( ) 2 2 q 29 .7 W ... emissivity of Nichrome wire. Electrical current. Temperature of air flow and surroundings. Velocity of air flow. (a) Surface and centerline temperatures of the wire, (b) Eff...

Ngày tải lên: 08/08/2014, 17:20

... temperature, volume and properties of pharmaceutical. Heat transfer coefficient at outer surface and dimensions of coil. FIND: (a) Expressions for T c (t) and T h,o (t), (b) Plots of T c (t) and T h,o (t) ... 8.34 KNOWN: Flow rate and inlet temperature of water passing through a tube of prescribed length, diameter and surface temperature. FIND: (a) Outlet water te...

Ngày tải lên: 08/08/2014, 17:20

... = 0.8 47 and ε = 1 – exp (-NTU) = 0. 571 . From Eq. (1), the air outlet temperature is then () () c,o c,i h,i c,i T T T T 17 C 0. 571 1 27 17 C 79 .8 C ε =+ − =°+ −°=° < The rate of heat transfer ... (a) Overall heat transfer coefficient, U, for the HXer, outlet temperature of cooling water, T c,o , and condensation rate of the steam h m  ; and (b) Compute and...

Ngày tải lên: 08/08/2014, 17:20

... dissipation rate, M is the mass of PCM, and h fg is the heat of fusion of PCM. Irradiation: G = σT w = 5. 67 × 10 -8 W/m 2 ⋅K 4 (1200 K) 4 = 1 17, 573 W/m 2 Emissive power: E b = ( ) 4 42 m T 872 73952W/mσσ=+= Emissivity: ... (Table 12.1) ε = 0.8 67 Absorptivity: α = α 1 F (0-λT) + α 2 (1 –F (0-λT) ) λT = 5 × 1200 = 6000 µm⋅K α = 0.005 × 0 .73 78 + 0.9 (1 – 0 .73 78) F 0...

Ngày tải lên: 08/08/2014, 17:20

... of heat transfer to tube without ash deposit, (b) Rate of heat transfer with an ash deposit of diameter D d = 0.06 m, (c) Effect of deposit diameter and convection coefficient on heat rate and contributions ... Dimensions and emissivity of double pane window. Thickness of air gap. Temperatures of room and ambient air and the related surroundings. FIND: (a)...

Ngày tải lên: 08/08/2014, 17:20