Example: Heat Exchanger

$-$ HX operating at steady$-$state.

$-$ Steam enters one stream of HX at $250$ kPa and $\backslash (90\backslash \%\backslash )$ quality and exits at same pressure as a saturated liquid.

$-$ Liquid oil enters the other stream of HX at $\backslash (29\backslash$mathrm$\{$~kg$\}/\backslash$mathrm$\{$s$\}\backslash )$ at $\backslash (20^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash )$ and exits as a liquid at $\backslash (100^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash )$ with negligible pressure change.

$-$ Kinetic and potential energy effects can be ignored.

$-$ The oil can be treated as in incompressible liquid with a constant specific heat of $\backslash (2\mathrm{.}0\backslash$mathrm$\{$~kJ$\}/\backslash$mathrm$\{$kgK$\}\backslash ).$

$-\backslash (10\backslash \%\backslash )$ of the energy transferred to the oil is lost to the surrounding air through stray heat transfer. There is no heat transfer between the surrounding air and water side of HX$.$

$-$ Determine mass flow rate of water through HX$.$