Engine jacket water will be used to cool engine lube oil using a finned, double tube heat exchanger.

Oil flowing at $4$ kg$/$s is cooled from $80$C to $60$C by jacket water entering at a temperature of $35$C and

leaving at $55$C$.$

Fluid

Engine Oil $($Annulus$)$

Density kg$/$m$^3$

$858$

Specific Heat kJ$/$kg C

$2\mathrm{.}140$

Viscosity kg$/$ms

$0\mathrm{.}0531$

Thermal Conductivity W$/$mK

$0\mathrm{.}1392$

Prandtl number

$789\mathrm{.}6$

Jacket Water $($Tube side$)$

$990$

$4\mathrm{.}180$

$0\mathrm{.}596$ x $103$

Length of hairpin $=3\mathrm{.}5$ m

Annulus nominal diameter $=2\mathrm{.}5$ in$,$ schedule $40$

Inner passage nominal diameter $1$ in$,$ schedule $40$

Number of fins $=38$

Fin height $=0\mathrm{.}0146$ m

Fin thickness $=0\mathrm{.}0015$ m

Material: Stainless AISI $316$

Thermal conductivity, k $=13$ W$/$m K

Number of tubes inside annulus $=1$

To be determined:

a$)$ velocities of both fluids

$0\mathrm{.}637$

$3\mathrm{.}91$

b$)$ overall heat transfer coefficients for these conditions

$1.$clean

$2.$fouled

c$)$ total heat transfer area of the heat exchanger with and without fouling $($OS design$)$

d$)$ surface area of the hairpin and the number of hairpins to be connected in series

e$)$ pressure drop, tube side and annulus

f$)$ pumping power, tube side and annuals

$1$