Heat Exchanger

[Maqboole]

Plz help i just dont knwo how to solve it i just want a little help.thz

 

Water at the rate of 68kg/min is heated from 35 to 37 C by oil having a specific heat of 1.9kj/kg C. The fluids are used in a counter double pipe heat exchanger, & ayhe oil enters the exchanger at 110 C & leave at 75 C/.The overall heat transfer coefficient is 320 W/m^2 C. Calculate the heat exchanger area.

 

Answer is 15.82 m^2

[insane_alien]

can you show us the method you used to get that value?

 

your off by 300%

[Maqboole]

I didt get this answer at all i got something else this is the answer what we are told by our teacher.

 

I wanted to use the formla A=Q/Utln

 

For that i used the formula Q=m cp t

then i used the formula for calculating tln = (t1-t2)/ln(t1/t2)

 

we are given u now when we use that we dont get the right answer

[insane_alien]

are you going to show us the numbers you got so we can show you where you went wrong?