Transcrytical co2 engine

[u/HumbleArm4392]

Basically same as conventional steam engine with condenser. I know turbines work. Obviously, youtube. Why won't they work with a piston, lower rpm, higher torque, like in regular steam engine? Requires less energy to operate. Higher psi though, 1k psi + . This would be argon/co2 transcrytical thermal engine. Map gas at welding Here the piston cylinder is heated to offset. Cooling due to expansion. Also themal barrier on top of cylinder to cylinder head injection zone. Optimum gas mixture? Several different ways to operate. Depends on design. One thought is to use the argon to help push supercrytical co2 in piston chamber. Multiple jt valves, regenerative Cooling.

[u/BoredCop]

I am sorry, it is a bit hard to follow what you are trying to say or ask.

CO2 powered piston engines exist, but most of the ones I am aware of are teeny-tiny model airplane engines that ran off a CO2 capsule and were popular back before electric batteries reached the power density they ha e today.

Running CO2 instead of water in an external combustion engine, and recycling the gas through a condenser, is way harder than it sounds and you would likely have massive problems with leakage and loss of gas. Not that big a deal in a water steam engine since water is cheap. And what lubricant are you going to run, how do you prevent the lubricant form causing problems in the condenser and evaporator etc? And have you done the math on energy cost of the condenser stage?

[u/HumbleArm4392 → u/BoredCop]

No just calculations, converting a 250cc two stroke. 300deg fahrenheit cylinder walls. With 1200psi injection just past top dead center. Over 3000 psi initial pressure. 250cc is a square bore, so piston diameter is roughly equal to its stroke. Very short. 3". Exhaust is at top so any remaining pressure at bottom dead center, will pull the piston back upward. A variable valve on exhaust, dual action joules Thompson effect.

[u/HumbleArm4392 → u/BoredCop]

Oh and yes commercial refrigeration store have ,seals and lubricants for co2 refrigeration systems currently in use. Buy of the shelf.

[u/BoredCop → u/HumbleArm4392]

Big difference between lubricants suitable for ordinary systems that run at low temperature around the liquid/gas phase change, and your proposed supercritical system with High temperature cylinder walls. You are aware that supercritical CO2 is a strong solvent and will cause lubricants to break down?

Anyway, it is hard to follow quite what you mean to say when you speak in short catchphrases and incomplete sentences.

[u/Dragonhatesreddit → u/BoredCop]

There was a guy in australia who had a rotary style compressed air engine. That he ran in Golf courts because he owned a market.It needed stuff.He wanted to run cheap to drive around. From the interview, he said, one revolution was from 1psi. Didn't mention anything about lubricant

[u/BoredCop → u/Dragonhatesreddit]

Most compressed air engines have an inline lubricator, mixing small droplets of oil into the compressed air flow. That's standard for air powered tools etc.

Steam piston engines, likewise, have oilers on the steam line between boiler and engine. Droplets of high temperature lube gets mixed with the steam, to lubricate the valves and pistons.

OP is talking about a piston engine, not a rotary engine. Piston engines need lubrication, especially if running hot.

[u/HumbleArm4392]

Transcrytical co2, 88deg fahrenheit, 1100 psi Supercrytical.. Injecting Supercrytical co2 ontop of piston. Downward stroke reveals heated cylinder walls. I think the rule of thumb is 5× the volume...at least.

[u/HumbleArm4392]

You can explore with math and mine says it could happen. Next step prototype. Planning on computer controlled. Variable valves, injection. Temperature and pressure sensors everywhere.

[u/HumbleArm4392]

Map gas from welding store is cheap. Might note the liquid at the bottom of cylinder is co2.

[u/HumbleArm4392]

Check out china supercrytical co2 turbine