1 Steam Cars : Phorum
General Steam Car topics
Liquid Co2
Posted by: chris thomas (IP Logged)
Date: August 14, 2005 01:24AM
<HTML>Has anyone considered using liquid co2, with a thermal expander, and recondensing system to power steam engines? At 120F the liquid co2 will put out about 1500PSI. This can be regulated down to 250psi or 200psi. It's expansion rate is 3000%.</HTML>
Re: Liquid Co2
Posted by: Tim Senior (IP Logged)
Date: August 14, 2005 10:02AM
<HTML>The problem is turning the gas back to a liquid. The critical temperature and pressures of carbon dioxide are about 500 psi and 30 centigrade. This means that the engine exhaust would have to be at least 200 psi with a condenser capable of taking the pressure and able to cool under 30 centigrade. You also have to store the liquid below the critical temperature or it will turn back to gas with a considerable pressure increase. All a bit difficult in a mobile plant.</HTML>
Re: Liquid Co2
Posted by: Andy Patterson (IP Logged)
Date: August 15, 2005 08:27PM
<HTML>Tim is basicly right.
I am not up on CO2 properties. But to be more specific the pressure would have to be above the saturation pressure at a specific temperature. And sense the critical temperature is around 30 C with a pressure around 500 PSI. I would think you would need be close to the 500 PSI critical point pressure and below 30 C to condense to a liquid. Seams impritical in a moble application.</HTML>
I am not up on CO2 properties. But to be more specific the pressure would have to be above the saturation pressure at a specific temperature. And sense the critical temperature is around 30 C with a pressure around 500 PSI. I would think you would need be close to the 500 PSI critical point pressure and below 30 C to condense to a liquid. Seams impritical in a moble application.</HTML>
Re: Liquid Co2
Posted by: Andy Patterson (IP Logged)
Date: August 15, 2005 08:31PM
<HTML>Woops didn't mean to post yet.
You should look at the CO2 saturation line to see what condenser pressure you would need for a given pressure.
30C = 86F
In any case would would have to get the temperature below the critical point.</HTML>
You should look at the CO2 saturation line to see what condenser pressure you would need for a given pressure.
30C = 86F
In any case would would have to get the temperature below the critical point.</HTML>
Re: Liquid Co2
Posted by: chris thomas (IP Logged)
Date: August 15, 2005 09:42PM
<HTML>The condensor to change it back to a liquid after it has been used is easy to build. It is similar to the radiator/condensor for a steam engine. At 88F you would need 1071 PSI to convert CO2 into a liquid. However using liquid nitrogen which can drop the temperature down to -56.6C, the pressure can be 5.2 Atm. Portable CO2 recondensors are available. They're just hard to find.
The system would run like this:
Liquid CO2 tank-heat expander-storage tank-motor-exhaust-condensor-liquid co2 pump-liquid CO2 tank.
The reason I asked, I'm about 3 months away from having a steam engine running on liquid CO2. I have a liquid co2 20lb tank, heat expander, storage tank (10lb@250PSI). I am working on the portable recondensor currently. I take it no one else is working on this type of idea? If not CO2 then how about ammonia or other state change gases?
Good chart for CO2 info: [scifun.chem.wisc.edu];
The system would run like this:
Liquid CO2 tank-heat expander-storage tank-motor-exhaust-condensor-liquid co2 pump-liquid CO2 tank.
The reason I asked, I'm about 3 months away from having a steam engine running on liquid CO2. I have a liquid co2 20lb tank, heat expander, storage tank (10lb@250PSI). I am working on the portable recondensor currently. I take it no one else is working on this type of idea? If not CO2 then how about ammonia or other state change gases?
Good chart for CO2 info: [scifun.chem.wisc.edu];
Re: Liquid Co2
Posted by: Ben in Maine (IP Logged)
Date: August 15, 2005 09:53PM
<HTML>Amonia is not friendly to man or metal,,,,hence it has been abandoned in refrigeration,,,Cheers Ben</HTML>
Re: Liquid Co2
Posted by: Arnold Walker (IP Logged)
Date: August 16, 2005 01:22AM
<HTML>Wow ....and I thought a small condensing turbine with decendant effeciency was rough to pull off.
Sounds like a cakewalk compared the recompressing trick you are pulling off.</HTML>
Sounds like a cakewalk compared the recompressing trick you are pulling off.</HTML>
Re: Liquid Co2
Posted by: Arnold Walker (IP Logged)
Date: August 16, 2005 01:41AM
<HTML>Reminds me of an aircar system .....Was sucking heat off the compressed air by running it thru a heating jacket (or would that be called a block preheat) in the expander.Upped the effeciency
on the air engine apparently.While reducing waste heat at the air storage tank.
Good luck on your idea...we need all the trailbrazers we can get.
Almost anything can beat some of stuff I hearing in energy PC crowd.
Hope , to see your "whatever it is" driving a car to a meet someday.</HTML>
on the air engine apparently.While reducing waste heat at the air storage tank.
Good luck on your idea...we need all the trailbrazers we can get.
Almost anything can beat some of stuff I hearing in energy PC crowd.
Hope , to see your "whatever it is" driving a car to a meet someday.</HTML>
Re: Liquid Co2
Posted by: Tim Senior (IP Logged)
Date: August 16, 2005 08:53AM
<HTML>Are you really considering using liquid nitrogen as a cooling agent? Why not use it as your working fluid, use it then loose it, it will save on the carbon dioxide.
Another thought. All steam cars loose water, even condensers, how will you replace your lost gas? I'm sorry to seem very negative and I hope that you can produce a working system but have my doubts.
Meantime water still works very well and it's cheap.</HTML>
Another thought. All steam cars loose water, even condensers, how will you replace your lost gas? I'm sorry to seem very negative and I hope that you can produce a working system but have my doubts.
Meantime water still works very well and it's cheap.</HTML>
Re: Liquid Co2
Posted by: chris thomas (IP Logged)
Date: August 16, 2005 08:57PM
<HTML>Liquid nitrogen is only a 1 to 696 expansion rate; liquid co2 is 3000% or 4.31 times greater than LN. LN is more plentiful but I want more expansion and steam is only 1700. Right now I'm going with CO2 because a co2 system is actually cheaper than a steam system or a LN system. I may eventually go to liquid nitrogen because after the initial investment and in the long run a liquid nitrogen system will be cheaper.
Because air has co2 and you can compress air and get liquid co2, liquid nitrogen, and other gas, I can recover some of my losses. Based upon the expansion rate of liquid co2 and the amount of cf/hr (5,170.28213 cf/hr@3600RPM) of air my engine uses, without any recondensing system I can drive on my engine for 104 days @ 10 hours per day. With a recondensor system I can drive all year on a 20lb tank of liquid co2. Total cost for 20lbs of liquid co2 is $22 or $77 if it exhausts to air. With my own CO2 facility it becomes cheaper overall. (The Dewar vessel is the most expensive unit.)
The question would then be, what is the total amount of fuel cost for operating a steam engine 10 hours per day for 104 days? and for 365 days? with liquid nitrogen as the propellant? Or has anyone considered using the exhaust gas from Hillary Eldridge's patent from 1898? In 1 hr you can produce the equivalent of 300 gallons of gas off of a 30vdc@5amp power source. The byproducts are much less than petroleum fuels.
My current engine design allows it to be mounted on any manual transmission vehicle with minimal problems. It will produce 287 hp@419 ft-lb of torque. It has 2in pistons, 200psi, 4in stroke. It works at a constant rpm of 3600. Unless someone knows of a simple way to increase and decrease pressure of an air spring, the rpms must be constant. Also if you need more torque it can be increased above 600ft-lb. Currently, this is done manually. Right now, we are preparing to mount it inside of a subaru. I would prefer to put it inside of a 70s model Ford pickup.</HTML>
Because air has co2 and you can compress air and get liquid co2, liquid nitrogen, and other gas, I can recover some of my losses. Based upon the expansion rate of liquid co2 and the amount of cf/hr (5,170.28213 cf/hr@3600RPM) of air my engine uses, without any recondensing system I can drive on my engine for 104 days @ 10 hours per day. With a recondensor system I can drive all year on a 20lb tank of liquid co2. Total cost for 20lbs of liquid co2 is $22 or $77 if it exhausts to air. With my own CO2 facility it becomes cheaper overall. (The Dewar vessel is the most expensive unit.)
The question would then be, what is the total amount of fuel cost for operating a steam engine 10 hours per day for 104 days? and for 365 days? with liquid nitrogen as the propellant? Or has anyone considered using the exhaust gas from Hillary Eldridge's patent from 1898? In 1 hr you can produce the equivalent of 300 gallons of gas off of a 30vdc@5amp power source. The byproducts are much less than petroleum fuels.
My current engine design allows it to be mounted on any manual transmission vehicle with minimal problems. It will produce 287 hp@419 ft-lb of torque. It has 2in pistons, 200psi, 4in stroke. It works at a constant rpm of 3600. Unless someone knows of a simple way to increase and decrease pressure of an air spring, the rpms must be constant. Also if you need more torque it can be increased above 600ft-lb. Currently, this is done manually. Right now, we are preparing to mount it inside of a subaru. I would prefer to put it inside of a 70s model Ford pickup.</HTML>
Re: Liquid Co2
Posted by: chris thomas (IP Logged)
Date: August 16, 2005 09:22PM
<HTML>Are there any sources for steam engine and boiler designs?</HTML>
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