Bolter:
(kE2 - kE1) = 0, (pE2 - pE1) = 0, w1-2 = 0
Now, q_{1-2} = w_{1-2 } (h_{2} - h_{1}) + (kE_{2} - kE_{1}) + (pE_{2} - pE_{1})
q_{1-2} = h_{2} - h_{1}
Heat supplied in boiler increases the enthalpy of system.
q_{1-2} = w_{1-2} (h_{2} - h_{1}) + (kE_{2} - kE_{1}) + PE_{2} - pE_{1}) - q_{1}-2 = h_{2} - h_{1}
Heat energy is lost by the system to the cooling water
q_{1-2} = h_{1} - h_{2}