Quality coming out of the turbine

[scott_for_the_game]

Another question. If your given the quality coming out of the turbine.

Why do you use say H2 = Hl + xv(Hv - Hl) to determine a xv even though u hav one given?

 

[Astronuc]

Another question. If your given the quality coming out of the turbine.

Why do you use say H2 = Hl + xv(Hv - Hl) to determine a xv even though u hav one given?

Well in a saturated 2 phase state, the total enthalpy is determined by the enthalpy in the liquid fraction and the enthalpy in the vapor one.

h = (1-x) h_l + x h_v = h_l + x (h_v - h_l) where x is the thermodynamic quality.

Normally in a turbine, the steam entering is superheated and becomes saturated as work is extracted (momentum transfered) from the working fluid to the rotor and stator blades.

 

[ravenprp]

The equation H2 = Hl + xv(Hv - Hl) is known as the quality equation and is used to determine the quality (xv) of a two-phase mixture (vapor and liquid) at a given state. This equation is based on the principles of thermodynamics and can be derived from the first law of thermodynamics. It is a useful tool in determining the state of a mixture and can be applied to various processes, including those involving turbines.

In the context of a turbine, the quality of the steam coming out of the turbine is an important factor in determining the efficiency and performance of the turbine. The quality of the steam refers to the amount of vapor present in the mixture, and it can greatly affect the amount of energy that can be extracted from the steam.

Using the quality equation allows us to calculate the quality of the steam at a given state, even if we are only given one other parameter, such as enthalpy. This is because the equation takes into account the properties of both the vapor and liquid phases, and their respective enthalpies. By knowing the enthalpy of the mixture and the enthalpies of the individual phases, we can solve for the quality and determine the amount of vapor present.

In summary, the quality equation is a useful tool in determining the state of a two-phase mixture, such as steam coming out of a turbine. It allows us to calculate the quality of the mixture, even if we are only given one other parameter. This equation is based on fundamental thermodynamic principles and is commonly used in engineering applications.