HeterosexusOfRome
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I am looking at problems 27.4 and 27.5 in the MERM companion and they both ask for the thermodynamic efficiency given the pump and turbine efficiency. The answer shows to use the steam tables then find all the enthalpies at all the stages and then find the actual enthalpies due to the pump and turbine inefficiency. I understand this method is the method shown in the book. However i did it another way and was wondering if my method is just as valid as i get the same answer.
The method i use is i found the enthalpy of the fluid right after the turbine and then determined how much heat will need to be ejected at the condenser to bring the vapor back down to the temperature of the saturated liquid as it enters the boilerfeed pump. As i said i got the same answer but what concerns me is i did not need to use the pump efficiency at all in my calculation (had to use the turbine efficiency though). Can some one please confirm if my methodology is valid and if any conditions make it invalid?
The method i use is i found the enthalpy of the fluid right after the turbine and then determined how much heat will need to be ejected at the condenser to bring the vapor back down to the temperature of the saturated liquid as it enters the boilerfeed pump. As i said i got the same answer but what concerns me is i did not need to use the pump efficiency at all in my calculation (had to use the turbine efficiency though). Can some one please confirm if my methodology is valid and if any conditions make it invalid?