Steam Turbine Power, Eficiency and Steam Quality
Steam Turbine Power, Eficiency and Steam Quality
(OP)
Hi to you all
I'm facing some questions on steam quality and Mollier Diagram direct reading.
I want to calculate a steam turbine eficiency. The turbine is feed with HPI (High pressure) steam (105bar,468ºC). There is one extraction to HPII steam (43,5bar,364ºC) and the rest is condensed to Vacuum (0.112bara, 50,2ºC).
Both HPI and HPII are superheated so the enthalpies are easy to read but the condensed steam is not 100% dry (saturated) since at 0.112bara the saturation temperature is 48.07ºC and the steam is at 50.2ºC. My question is the steam quality calculation. How should I do it or read it on the Mollier diagram? I just want to calculate the enthalpy of the condensed steam (liquid and vapour). That's why I need the steam quality.
Thanks,
AndreChE
I'm facing some questions on steam quality and Mollier Diagram direct reading.
I want to calculate a steam turbine eficiency. The turbine is feed with HPI (High pressure) steam (105bar,468ºC). There is one extraction to HPII steam (43,5bar,364ºC) and the rest is condensed to Vacuum (0.112bara, 50,2ºC).
Both HPI and HPII are superheated so the enthalpies are easy to read but the condensed steam is not 100% dry (saturated) since at 0.112bara the saturation temperature is 48.07ºC and the steam is at 50.2ºC. My question is the steam quality calculation. How should I do it or read it on the Mollier diagram? I just want to calculate the enthalpy of the condensed steam (liquid and vapour). That's why I need the steam quality.
Thanks,
AndreChE





RE: Steam Turbine Power, Eficiency and Steam Quality
RE: Steam Turbine Power, Eficiency and Steam Quality
But I can't read the steam quality on the Mollier Diagram for example at 45 or 40ºC
RE: Steam Turbine Power, Eficiency and Steam Quality
Enthalpy of steam before condensation = Saturated steam enthalpy at 0.112 bara + Cp*Degree of superheat
where Degree of super heat is
T - Tsat = (50.2 - 48.07)
Cp = 1.87 kJ/kg K is for around 50 deg C water vapour
Heat removed from the steam in the condenser (if there is no sub cooling) = Latent heat of the steam at 0.112 bara + Cp*Degree of superheat
Now you can calculate the enthalpy of the condensed steam.
Regards,
KMPillai
Regards,
KMPillai
RE: Steam Turbine Power, Eficiency and Steam Quality