Open Systems

[profitis]

Milehigh says:'So what happens if you compress the piston and then wait three
hours for the compressed gas to cool down and then you release
the piston?'

I say: WHO compressed the piston.it was two individuals who dumped work into the system.two were taxed.tinman is piggybacking ontop of the other guys efforts and gaining in the process.the other guy is called mr environment.mr environment is dumping  heat into the begin of compression cycle.mr environment is also reclaiming his heat at end of cycle.

[LibreEnergia]

@MH&MarkE
If we are to use your ideal gas laws, then in all fairness we are to use an ideal piston/cylinder for this experiment.
The pistion is in the start position-there is no friction in this cylinder/pistion setup. Put a pressure of 5psi gage pressure into the cylender. The cylinder has an ideal insulation. Now push the piston 3/4 of the way down the cylender. The pressure rises, and the temp rises. Leave in the compressed state for 1minute, then let the piston return to the starting point. The pressure will once again be 5psi-all energy has been returned and yet there was a temperature increase.
What caused the temperature increase if all the energy was returned?

So why don't perform this experiment. If you do you'll realise you have been mistaken all along.

What you will find is that when compressed the temperature of the gas rises. The rise in proportional to the amount of work done to compress it. The WORK is converted to HEAT...

When it decompresses the HEAT is converted to WORK. It is as simple as that.

What happens in reality of course is that we don't have a perfectly insulated cylinder and heat losses occur. However these losses
don't ever add to the efficiency of the conversion process. Likewise the fact that our working fluid is not a perfect gas.

[profitis]

Mr libre says:'What you will find is that when compressed the temperature of
the gas rises.'


I say: minus the cooling effect of phase-change liquid>gas

[LibreEnergia]

Mr libre says:'What you will find is that when compressed the temperature of
the gas rises.'


I say: minus the cooling effect of phase-change liquid>gas

And then perhaps you may have re-invented the refrigerator.

Hopefully you are not going to describe that as a free energy device...

[profitis]

Libre says: 'a refrigerator-  hopefully you are not going to describe that as a free energy
device...'

I say: of course not don't be silly.tinmans device is a free energy  device