Question

For the given system find

1) The total amount of heat exchange (W)

2) The temperature of the water at the outlet (degC)

All information should be included, the pipe is made of copper and the internal fluid is water, external fluid is air

0.mer Temp at outlet? colm =5cm Heat exchange? Quotol=? water Copper in = 8k915 Ti = 93°C av 1930 1,29806 T2=? M = 15 mis Too = 15°C

Water is flowing through a copper tube of lenght 1 m, diameter 5 cm and thickness 0.8mm, at a rate of 0.8 kg/s, and an inlet temperature 93 degC. If the tube is exposed to Air at u=15 m/s and Tinf=15degC, find

1) The total amount of heat exchanged in the system

2) The tempature of the water at the outlet (T2).

Answer 1

given - water - m20.8kgla 0.8 mm. Lalm - Air + 9 Jos = Ismla Too=15°c. For Air :- TI = 93+15 S =54c = 327K Properties at 327k - = 2.03x10-5 K=0.028 ; Pr=0.7 = tool x 102 - 1.08 Kylm3. (287) +327) Re = (1.08)x(15) x(0.0516) 341162 2:03 x 10- 5 0.028 -X 00S16 ? C y. Coo2 2 60 0.80 ) X (0.7 ( = 66.44 m hoc

For water :- at 93°C. M = 3.06410-y ,k=0.678, Po=1.90. be - (0.05) (0.87X(4) t x(0.05)?x (3.06x10Y) 66.574. chw = 0.678) * (0.023) (66,579] 04 (1999 0.5 = 2911 om . The total amount of heat exchanged in the system is :- G . That m Ź s. Rwater & Raio | 19.3.-15) XI x1 m) (66574 X 0.0516) (29 11x (oos) = 82L wim

The tempature of the water cet the outlet (Tal. 9 = m Cp (Te-98c) = 2911 x 17 x 0.05x1 (Te-15) 2007 Te-930) = 2911xIT TO OSX1 (Te-15) 1 Te = 197°C 7