water air composite pressure system

[apurvmj]

Hi all,

I,m plannig to conduct one experiment, but before that I wanted it confirm whether my idea has got some scence.

My query is lets consider we have 3 types of system

 

1.Closed air tank at 10 bar pressure.

It will have pressure* volume = 10*10⁵*1= 1000 KJ energy.

 

2. Water tank of volume 1 cum and height of water 1 m.

It will have 5.04*h² = 5.04 KJ (h= water head pressure)

 

3. Now lets say we have 2 cum of closed volume containing water of 1 cum and 1 cum air at 10 bar.

can I say we have energy in water= 5.01*100² = 50400 KJ (10 bar=100 m of water)

plus when water is out of tank volume of air will be 2 cum at 5 bar.

then energy stored in air (considering isothermal expansion)= 500 KJ

so total 50900 KJ.

 

Am I doing wrong some where/ everywhere then where is it wrong?

If not why there is so diffrence in energy?