Open Systems

[tinman]

LibreEnergie is not suggesting that the environment is adding energy to the tanks over and above what was originally there.  When the valve opens and the gasses are moving the small more pressurized tank temperature drops, while the bigger tank at 1 ATM heats rejecting heat to the environment.  If you put the whole thing in one really well insulated container then as the tanks equalize, their temperatures will also equalize getting much colder in the process.  It takes heat from outside to restore the total energy seen as the sum total PV of the combined tanks.

The longer it takes the tanks to equalize the less sever the temperature and pressure drop will be.  By the seat of my pants a couple of minutes is probably short enough that you will see a significant temperature drop and pressure shortfall versus the constant energy / constant PV produce hypothesis that you are testing.

We will call the small tank(10ltr) tank A,and the larger tank(20ltr)tank B from here on in.

So to sum it up,if we pressurise tank A to 40psi gauge pressure,and release that pressurised gas into tank B,to be an equil amount of energy now in both tanks that equils the energy we had in tank A to start with,the pressure in each tank would have to be 13.3psi-->is this correct?.

[MarkE]

We will call the small tank(10ltr) tank A,and the larger tank(20ltr)tank B from here on in.

So to sum it up,if we pressurise tank A to 40psi gauge pressure,and release that pressurised gas into tank B,to be an equil amount of energy now in both tanks that equils the energy we had in tank A to start with,the pressure in each tank would have to be 13.3psi-->is this correct?.

13.3psi gauge and constant temperature is what would result without any energy loss.  Constant energy is what you have claimed, and LE and I dispute. 

After equalization of temperature and pressure the energy in each tank is proportional to its respective volume.  E = PV.

Applying textbook thermodynamics:  Were the system to equalize instantly the A tank pressure would fall to 5.3psi gauge while the B tank pressure rises to 5.3psi gauge and the temperature in each would if allowed to equalize while perfectly insulated from the outside world at -59C.  It won't equalize instantly so the pressure will be between 5.3psi gauge and 13.3 gauge, and the temperature will bottom out between -59C and the starting stabilized temperature.  Once the pressure and temperature bottom out, the environment will reheat the contents so that if you come back say an hour later the temperature will be very close to the outside air temperature and the pressure will be very close to 13.3psi.

If you were to only partially equalize then the A tank would cool and the B tank would heat during each transfer.

[tinman]

13.3psi gauge and constant temperature is what would result without any energy loss.  Constant energy is what you have claimed, and LE and I dispute. 

After equalization of temperature and pressure the energy in each tank is proportional to its respective volume.  E = PV.

Applying textbook thermodynamics:  Were the system to equalize instantly the A tank pressure would fall to 5.3psi gauge while the B tank pressure rises to 5.3psi gauge and the temperature in each would if allowed to equalize while perfectly insulated from the outside world at -59C.  It won't equalize instantly so the pressure will be between 5.3psi gauge and 13.3 gauge, and the temperature will bottom out between -59C and the starting stabilized temperature.  Once the pressure and temperature bottom out, the environment will reheat the contents so that if you come back say an hour later the temperature will be very close to the outside air temperature and the pressure will be very close to 13.3psi.

If you were to only partially equalize then the A tank would cool and the B tank would heat during each transfer.

Well i have carried out over ten test now,and the results are always within 2 decimal points,both in temperature and pressure. Never once did i see a tem drop any where near -59*C-->something is amiss there

I ran 5 calibrated test,and averaged out the results over the 5 test. As i stated,all ten test carried out only seen a .2 swing either way in temp and pressure.
The results are as below.


Tank A-1 ATM-temp 22*C-->that is also the ambiant temperature at the time of the test's.
Tank B-1 ATM-temp 22*C

Tank A pressurised to 40 psi gauge pressure-temp 29*C

Valve opened to tank B ,and aloud to equalise.
Pressure tank's A&B=13.5psi
Temp tank A=19*C
Temp tank B=31*C

Left for 2 minutes.
Pressure tank's A&B-13.5psi
Temp tank A=22*C
Temp tank B=24*C

The added plumbing has added 65mL to tank A,and 50mL to tank B

[MarkE]

Well i have carried out over ten test now,and the results are always within 2 decimal points,both in temperature and pressure. Never once did i see a tem drop any where near -59*C-->something is amiss there

I ran 5 calibrated test,and averaged out the results over the 5 test. As i stated,all ten test carried out only seen a .2 swing either way in temp and pressure.
The results are as below.


Tank A-1 ATM-temp 22*C-->that is also the ambiant temperature at the time of the test's.
Tank B-1 ATM-temp 22*C

Tank A pressurised to 40 psi gauge pressure-temp 29*C

Valve opened to tank B ,and aloud to equalise.
Pressure tank's A&B=13.5psi
Temp tank A=19*C
Temp tank B=31*C

Left for 2 minutes.
Pressure tank's A&B-13.5psi
Temp tank A=22*C
Temp tank B=24*C

The added plumbing has added 65mL to tank A,and 50mL to tank B

A couple of comments and questions: 

How have you fixtured your temperature sensors?  Are they suspended in the tanks or are they in contact with the tank walls? 

How long does it take your tanks to equalize? 

How heavy are your tanks proper? 

Did you let tank A come back down to your 22 ambient before connecting it to tank B, or did you connect it while it was still warm?  You should find that if you fill tank A to 40 psi gauge and then let it sit that the pressure drifts down and it will take a series of shorter and shorter top-ups from your pressurized air source to get tank A to 40 psi gauge and keep it there after it is allowed to sit.

The indication of pressure at 13.5psi gauge suggests that enough heat is coming back from the tank walls to reheat the gas.

[tinman]

A couple of comments and questions: 

  You should find that if you fill tank A to 40 psi gauge and then let it sit that the pressure drifts down and it will take a series of shorter and shorter top-ups from your pressurized air source to get tank A to 40 psi gauge and keep it there after it is allowed to sit.

How have you fixtured your temperature sensors?  Are they suspended in the tanks or are they in contact with the tank walls?

The temp sensors are suspended in the tanks ,so as they in the center of the tanks.

How long does it take your tanks to equalize?

I can controll the flow rate,and tried a few different times,from instant(within a second),and up to 30 seconds. There didnt seem to be much difference.

How heavy are your tanks proper?

Tanks proper?. Im guessing here,but do you mean mounting bracket's?. If so,there isnt any,the tanks are just sitting on the wodden bench ATM.

Did you let tank A come back down to your 22 ambient before connecting it to tank B, or did you connect it while it was still warm?

They were conected while still warm. I will carry out those test after dinner tonight-->letting the temperature drop back down to ambiant before opening the valve to tank B.

The indication of pressure at 13.5psi gauge suggests that enough heat is coming back from the tank walls to reheat the gas.

This is a good thing for our setup to acheive it's goal.