Operating a Stirling Engine inside a Pressure Vessel
Posted: Sun Dec 15, 2013 10:44 am
My science fair investigates the effect of air pressure on the efficiency of a Stirling engine.
Due to the difficulty of actually pressurizing a Stirling engine, I have decided to increase pressure by operating the Stirling engine inside a pressure vessel.
I'm using a Cornelius keg (rated for 130 psi) as a pressure vessel, and the maximum pressure I'll be testing with will be ~ 87 psi (6 bar).
The keg has an opening of 4 3/4," an actual diameter of 9" on the inside, and a height of 25 inches.
I have found a tutorial on making a Stirling engine that could fit through the hole, so that is not an issue.
But here are my questions:
Firstly, would the pressure crush the Stirling engine, or would the internal pressure of the Stirling engine rise quickly enough to balance the external pressure?
Secondly, you have to give the Stirling engine a little nudge to get it started. How could I do that remotely?
I would have to put a heat source inside the pressure vessel, and I will probably be using almost-boiling water. I might add salt in the water to obtain a high temperature without actually boiling the water. Would the temperature of the water cause a notable increase in the pressure of the pressure vessel?
I would measure the rpm of the Stirling engine by a optical tachometer placed near the lid of the keg. The Stirling engine I plan to build for the experiment has a vertical flywheel, so it would work well. How could I remotely use the tachometer? Could I simply press down the laser button with tape? Because the tachometer description said it would store the last reading it measured.
Lastly, how will I place all of this stuff inside the keg? Are there any giant "pliers" that would suffice for my experiment?
Thanks.
Due to the difficulty of actually pressurizing a Stirling engine, I have decided to increase pressure by operating the Stirling engine inside a pressure vessel.
I'm using a Cornelius keg (rated for 130 psi) as a pressure vessel, and the maximum pressure I'll be testing with will be ~ 87 psi (6 bar).
The keg has an opening of 4 3/4," an actual diameter of 9" on the inside, and a height of 25 inches.
I have found a tutorial on making a Stirling engine that could fit through the hole, so that is not an issue.
But here are my questions:
Firstly, would the pressure crush the Stirling engine, or would the internal pressure of the Stirling engine rise quickly enough to balance the external pressure?
Secondly, you have to give the Stirling engine a little nudge to get it started. How could I do that remotely?
I would have to put a heat source inside the pressure vessel, and I will probably be using almost-boiling water. I might add salt in the water to obtain a high temperature without actually boiling the water. Would the temperature of the water cause a notable increase in the pressure of the pressure vessel?
I would measure the rpm of the Stirling engine by a optical tachometer placed near the lid of the keg. The Stirling engine I plan to build for the experiment has a vertical flywheel, so it would work well. How could I remotely use the tachometer? Could I simply press down the laser button with tape? Because the tachometer description said it would store the last reading it measured.
Lastly, how will I place all of this stuff inside the keg? Are there any giant "pliers" that would suffice for my experiment?
Thanks.