what is the difference between waste heat recovery boiler and waste heat recovery in boiler?
A waste heat recovery boiler is a boiler that specifically does only that function, there is waste heat from a process and the boiler is added to turn that heat into steam. There is no actual furnace or firing section in the boiler. An example is what is called a heat recovery steam generator that is put on the output of a combustion turbine. Have both is called a combined cycle generating unit. A boiler that also recovers heat has a furnace section in it, fuel is burned in the boiler but it also has additional heat transfer equipment added to it to extract the energy that would have gone up the stack. This heat may be used in another process or may be used to make the boiler more efficient by preheating the combustion air or feedwater.
