(shell and tube heat exchanger) water flowing at a rate of 3.8 kg/s is heated from 38°c to 55°c in the tubes of a shell-and-tube heat exchanger. the shell side is one-pass with water, flowing at 1.9 kg/s, entering at 94°c. the overall heat transfer coefficient is 1420 w/(m2*k). the average water velocity in the tubes (1.905 cm inner diameter with a wall thickness of 0.5 cm) is 0.366 m/s. because of space limitations, the tubes may not exceed 2.44 m in length. determine the required number of tube passes, the number of tubes per pass, and the length of tubes consistent with this restriction.

it takes about 30 days for it to break down

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day

its a 5.5 n

glad that

e/c, where e is its total energy