Solution :
The mass flow rate of the cooling water is determined from the energy balance equation. The enthalpies of the refrigerant at the initial and the final states were obtained from A-13 and A-12 for the given parameters.
Therefore by energy balance equation,
[tex]$\dot m_r h_{r1}=\dot m_w \Delta h_w +\dot m_r h_{r2} $[/tex]
[tex]$\dot m_w = \frac{\dot m(h_1-h_2)_r}{c \Delta T}$[/tex]
[tex]$\dot m_w = \frac{8(308.34-88.82)}{4.18 \times 10}$[/tex]
= 42 kg / min
