Latent heat of vaporization Water thermodynamic

[firavia]

Latent heat of vaporization "Water" thermodynamic

-first of all I want to know if the "latent heat of vaporiasation " of water is related to the initial pressure of water ?

-If LHV of water is variable with the variation of pressure , how can we calculate the heat needed to vaporise a certain mass of water inside a container , cause as we know while heating the container and water start to evaporate the pressure inside the container will increase gradually , so the heat needed to complete the vaporisation must be increased cause the LHV has changed with the change of pressure inside the container , please help

 

[turbo]

You should look up "steam table" as a beginning. This stuff is quite well-understood, since it was the foundation for much of the industrial revolution.

 

[Q_Goest]

Yes, Ufg (and Hfg) decrease with increasing P.

You can solve the problem simply applying the first law of thermo. Easiest way IMHO is to apply numerical methods using a computerized data base. This same type of problem comes up quite a bit in the industrical gas business for cryogenic liquids.

 

[CFDFEAGURU]

Here is the best steam table book out there.

https://www.amazon.com/dp/0894646850/?tag=pfamazon01-20

Thanks
Matt

 

[ank_gl]

-first of all I want to know if the "latent heat of vaporiasation " of water is related to the initial pressure of water ?

-If LHV of water is variable with the variation of pressure , how can we calculate the heat needed to vaporise a certain mass of water inside a container , cause as we know while heating the container and water start to evaporate the pressure inside the container will increase gradually , so the heat needed to complete the vaporisation must be increased cause the LHV has changed with the change of pressure inside the container , please help

What do you mean by "initial" pressure of water?

I am having trouble in visualizing the system you described. If its a closed system & is being heated, pressure in the container remains same while vaporization, and LHV is constant for a pressure.