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2 stroke steam flash engine
Posted by: Damijan Ruzic (IP Logged)
Date: March 13, 2005 09:44AM
<HTML>Well, Gentlemen,
How do you like an Idea of 2 stroke flash steam engine?
Presuming that we have U.S.S. (ultra short stroke) engine with 2 valves (intake and exhaust) in the oposite sides of cylinder and hot watter injector in the centre of the engine head.
We supose that we fill in the air in one part of cylinder volume, say, 60 %, than we compress air and than we inject hot watter into heated and compressed air in piston top position. Hot watter flash into hot air, giving qvick expansion, so we expand this mixture of hot air and steam to all volume and export it through exhaust valve than expansion is finished.
Than we open intake valve and let air in. Coming air must throw out remains of steam an air, so we have this proces done and lock first exhaust and than intake valve. In this moment we have piston allready in allmost medium position in cylinder, so we have bigger expansion chamber than compression chamber.
You can call it "Ruzic steam cycle" if you like the name, but, first of all I am interested to hear your comments.
Best regards,
Damijan Ruzic</HTML>
How do you like an Idea of 2 stroke flash steam engine?
Presuming that we have U.S.S. (ultra short stroke) engine with 2 valves (intake and exhaust) in the oposite sides of cylinder and hot watter injector in the centre of the engine head.
We supose that we fill in the air in one part of cylinder volume, say, 60 %, than we compress air and than we inject hot watter into heated and compressed air in piston top position. Hot watter flash into hot air, giving qvick expansion, so we expand this mixture of hot air and steam to all volume and export it through exhaust valve than expansion is finished.
Than we open intake valve and let air in. Coming air must throw out remains of steam an air, so we have this proces done and lock first exhaust and than intake valve. In this moment we have piston allready in allmost medium position in cylinder, so we have bigger expansion chamber than compression chamber.
You can call it "Ruzic steam cycle" if you like the name, but, first of all I am interested to hear your comments.
Best regards,
Damijan Ruzic</HTML>
Re: 2 stroke steam flash engine
Posted by: Tim Senior (IP Logged)
Date: March 13, 2005 11:10AM
<HTML>You have to have enough energy (heat in the water) to produce the power, compressing the air will take a lot, it all has to come from the water and the only way to get that is to turn it to steam to utilise the latent heat of vaporisation. This can't be done in the cylinder.</HTML>
Re: 2 stroke steam flash engine
Posted by: Andy Patterson (IP Logged)
Date: March 14, 2005 04:59PM
<HTML>Hi Damijan
Tim is about right. The heat in the compressed air is negitive work to the engine. It took shaft work to compress that air. And due to losses it can not all be recovered by expansion. The +work must come from the heat not produced by compression.
Now hot head engines do work. But they are putting a lot of heat into the entering steam and the hot head adds a bit. But as the RPM goes up less and less heat can be transfered from the head to the steam.
I takes a finite amount of time to transfer heat. And vaporazation also takes time. Going from liquid to vapor in the engine just puts additional limits on the process. None of which are a +.
Andy</HTML>
Tim is about right. The heat in the compressed air is negitive work to the engine. It took shaft work to compress that air. And due to losses it can not all be recovered by expansion. The +work must come from the heat not produced by compression.
Now hot head engines do work. But they are putting a lot of heat into the entering steam and the hot head adds a bit. But as the RPM goes up less and less heat can be transfered from the head to the steam.
I takes a finite amount of time to transfer heat. And vaporazation also takes time. Going from liquid to vapor in the engine just puts additional limits on the process. None of which are a +.
Andy</HTML>
Re: 2 stroke steam flash engine
Posted by: Damijan Ruzic (IP Logged)
Date: March 15, 2005 11:41AM
<HTML>Well,
Might it be you are partialy right, but I must admit that 4 stroke steam engine works on similar principle and hot watter injectors are available today.
This could be an advantage, you know, if you heat the watter and heat head of the engine with remaining heat you can easily "flash" steam into cylinder becouse of the hot air inside it.
Beside of that we have expanding volume larger than compression volume in this case, so we can profit a little in this case too (like in Atkinson/Miller cycle with 4 stroke petrol engines).
At least we do not need real boiler for such engine. Spiral barrell around burner's nozle is enough.</HTML>
Might it be you are partialy right, but I must admit that 4 stroke steam engine works on similar principle and hot watter injectors are available today.
This could be an advantage, you know, if you heat the watter and heat head of the engine with remaining heat you can easily "flash" steam into cylinder becouse of the hot air inside it.
Beside of that we have expanding volume larger than compression volume in this case, so we can profit a little in this case too (like in Atkinson/Miller cycle with 4 stroke petrol engines).
At least we do not need real boiler for such engine. Spiral barrell around burner's nozle is enough.</HTML>
Re: 2 stroke steam flash engine
Posted by: Andy Patterson (IP Logged)
Date: March 21, 2005 08:23PM
<HTML>Flash boiling in the past, as used in early steam cars, is not the same as is now defined in engineering books. The old flash boiler transfered large amounts of heat to water under pressure on demand. That limited the amount of steam that could be produced. Eventially the early flash systems were replaced by monotube (once through) boilers. In modern engineering texts flash steam generation is done by droping the pressure. Liquid changes to steam. The process is a nonwork process. The modern flash steam process does not produce work. It is not the same as the old flash steam systems used in early automobiles.
There is avery big differance between heat being added to the working substance, increassing it's vapor pressure, pushing against a piston, producing work moving the piston and liquid flashing to steam because of increassing volume as the piston moves, lowering pressure in the cylander. In the first case the working is produceing work because of heat added to it. In the second work is being done moving the piston causing the steam to flash into steam as the pressure drops.
Figure the amount of heat required to produce power. Can you show that you have enough area and time to transfer the amount of heat required for the expected power.
Andy</HTML>
There is avery big differance between heat being added to the working substance, increassing it's vapor pressure, pushing against a piston, producing work moving the piston and liquid flashing to steam because of increassing volume as the piston moves, lowering pressure in the cylander. In the first case the working is produceing work because of heat added to it. In the second work is being done moving the piston causing the steam to flash into steam as the pressure drops.
Figure the amount of heat required to produce power. Can you show that you have enough area and time to transfer the amount of heat required for the expected power.
Andy</HTML>
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