fundamentals of heat and mass transfer solutions manual phần 8 ppsx

... 79 .8 C ε =+ − =°+ −°=° < The rate of heat transfer to the air is () pc,o c,i q mc T T 0.03kg/s 1008J/ kg K 62 .8 C 1900 W =−=×⋅×°=  and the rate of condensation is 4 cond 6 fg q 1900W m 8. 70 ... = C min /C max = (5,000 × 41 78) /(10,000 × 4 188 ) = 0.499. Combining Eqs. (1) and (2), find ( ) ( ) 3 h,o T80C0.73 48. 210W/10,000/3600kg/s4 188 J/kgK =°−×××⋅ ( ) h,o T8021.0C5...

Ngày tải lên: 08/08/2014, 17:20

... 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) Effect of flow velocity and ... stream velocity and temperature of air coolant. (a) Average pin convection coefficient, (b) Pin heat transfer rate, (c) Total heat rate, (d) Effect of velocity an...

Ngày tải lên: 08/08/2014, 17:20

... condition of ε = 0.05, T s = T sur + 10 = 35°C = 3 08 K and T sur = 25°C = 2 98 K, find that () ( ) 82 4 223 2 r h 0.05 5.67 10 W m K 3 08 2 98 3 08 2 98 K 0.32W m K − =×× ⋅ + + = ⋅ < () () 3 82 4 ... 0.1m 25m 7 .85 m . ππ == ×= Hence, () () 22 82 4444 q 7 .85 m 10 W/m K 150 25 K 0 .8 5.67 10 W/m K 423 2 98 K −  =⋅−+××⋅−   ()() 22 q 7 .85 m 1,250...

Ngày tải lên: 08/08/2014, 17:20

... thickness and thermal conductivity of steel tubes. Temperature of steam flowing through the tubes. Thermal conductivity of insulation and emissivity of aluminum sheath. Temperature of ambient air and ... Temperature and volume of hot water heater. Nature of heater insulating material. Ambient air temperature and convection coefficient. Unit cost of electric power. FI...

Ngày tải lên: 08/08/2014, 17:20

... 185 185 185 185 ← initial estimate 1 186 .3 186 .6 186 .6 105 .8 2 187 .1 187 .2 167.0 96.0 3 187 .4 182 .3 163.3 94.2 4 184 .9 180 .8 162.5 93 .8 5 184 .2 180 .4 162.3 93.7 6 184 .0 180 .3 162.3 93.6 7 183 .9 ... 250 275 300 0 180 .7 180 .2 1 78. 4 175.4 171.1 165.3 1 58. 1 149.6 140.1 129.9 119.4 1 08. 7 98. 0 25 204.2 203.6 201.6 1 98. 2 193.3 186 .7 1 78. 3 1 68. 4 157.4 145.6 133.4 12...

Ngày tải lên: 08/08/2014, 17:20

... 0 85 85 85 85 20 1 85 85 85 52.5 20 2 10 85 85 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 ... 90 287 .6 305 .8 315.2 321.5 323.5 324.5 325 325 6 1 08 285 .6 301.6 313.5 319.3 322.7 324.0 324.5 325 7 126 281 .8 299.5 310.5 317.9 321.4 323.3 324.2 8 144 279 .8 296.2 3...

Ngày tải lên: 08/08/2014, 17:20

... PROBLEM 8. 28 KNOWN: Inlet temperature, flow rate and properties of hot fluid. Initial temperature, volume and properties of pharmaceutical. Heat transfer coefficient at outer surface and dimensions ... , π − ==× mc um/A2 .83 m/s, ρ == and with D Re 38, 980 , = Fig. 8. 3 yields f ≈ 0.022. Hence, () 2 324 2 .83 m /s 5m p 0.022 5.391kg /m 95N /m 9.4 10 atm 2 0.05m − ∆≈...

Ngày tải lên: 08/08/2014, 17:20

... 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 ... % # % # % 32 3 3 62 62 5 9 8 0 0033 273 015 1 589 10 22 5 10 3 08 10 and from Eq. 9.34, () () () 2 2 1/6 5 1/6 s,i D,i o 8/ 27 8/ 27 9/16 9/16 i 0. 387 3. 08 10 T T...

Ngày tải lên: 08/08/2014, 17:20

... T = 289 8 µm⋅K, it follows that λ max(e) = 289 8 µm⋅K/400 K = 7.25 µm and λ max(r) = 289 8 µm⋅K/273 K = 10.62 µm. < λ = 7.25 µm: Table 12.1 → I λ,b (400 K) = 0.722 × 10 -4 (5.67 × 10 -8 )(400) 5 ... 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 = 117,573 W/m 2 Emissive powe...

Ngày tải lên: 08/08/2014, 17:20

... Dimensions and emissivity of double pane window. Thickness of air gap. Temperatures of room and ambient air and the related surroundings. FIND: (a) Temperatures of glass panes and rate of heat transfer ... of ash deposit. Convection coefficient and temperature of gas flow over the tube. Temperature of surroundings. FIND: (a) Rate of heat transfer to tube...

Ngày tải lên: 08/08/2014, 17:20