A steam power plant receives heat from a furnace at a rate of 280 GJ/h. Heat losses

Question:

A steam power plant receives heat from a furnace at a rate of 280 GJ/h. Heat losses to the surrounding air from the steam as it passes through the pipes and other components are estimated to be about 8 GJ/h. If the waste heat is transferred to the cooling water at a rate of 145 GJ/h, determine
(a) Net power output and
(b) The thermal efficiency of this power plant.