Thanks to all At first I ...

Thanks to all

At first I should correct my question. Indeed I meant that "do I need to consider the energy of steam entered to  vacuum ejectors  also?"

And next, thank you Hamid for your useful information. By the way, I'm not sure to use the cooling water enthalpy instead of return condensate enthalpy (although the deference is negligible, I think). 

In fact I did this calculation in this way:   Energy level = Sigma [M * (H_Stream- H_return condensate)]

And the results have a good accordance with the thermo flow results.