# Will cars have "Steam Engines" again?



## n4zou (Jul 23, 2013)

Just found this and thought it might be interesting to all here.

*[ame="http://youtu.be/NOImbv_xcT8"]Dearman  Engine Company[/ame]*


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## lohring (Jul 24, 2013)

It's a heat engine that appears to come closer to the ideal Carnot efficiency than conventional heat engines.  However, it operates in a fairly low temperature range which will limit its efficiency in converting heat to work.  That will make it useful for converting waste heat to power, but probably will limit its use as a prime mover.  The thing I didn't see was a description of how the liquid air is converted back to a gas.  That requires significant power to run a compressor and cooling system.  The mechanical part is a low temperature steam engine.  That's a very well understood technology.  It's being studied by a reputable research company, otherwise I would dismiss it as just another idea that wasn't going to go far.

Lohring Miller


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## n4zou (Jul 29, 2013)

lohring said:


> It's a heat engine that appears to come closer to the ideal Carnot efficiency than conventional heat engines.  However, it operates in a fairly low temperature range which will limit its efficiency in converting heat to work.  That will make it useful for converting waste heat to power, but probably will limit its use as a prime mover.  The thing I didn't see was a description of how the liquid air is converted back to a gas.  That requires significant power to run a compressor and cooling system.  The mechanical part is a low temperature steam engine.  That's a very well understood technology.  It's being studied by a reputable research company, otherwise I would dismiss it as just another idea that wasn't going to go far.
> 
> Lohring Miller


The liquid gas is warmed by ambient air and the injected fluid. In the process of going from a liquid to a gas in the plumbing system and cylinder the gas expands almost 800%. It's more efficient than current electric cars. This system also eliminates the problems electric cars have. Liquid air is not under pressure so it can be pumped into a tank the same way you pump gasoline into your car. That eliminates heavy, toxic batteries and the time it takes to recharge them. Filling stations will simply use the air around the station to produce Liquid air so only electricity is required to produce it. Also don't forget the large temperature differential   involved. Liquid air changes to a gas at about -77 degrees so even winter  temperatures in areas below the arctic circles will allow the engine to function properly. I've become very fascinated with this concept.


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## Goldflash (Jul 29, 2013)

What is the real efficiency. It stills require power to make the liquid  Gas. That requires normally Electricity which can either be made from reusable sources or fossil fuels. Liquid gases also have all their own unique problems with storage and containment and at super low temperatures requires careful handling. 
I hope that the efficiency stacks up.


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## lohring (Aug 1, 2013)

n4zou said:


> The liquid gas is warmed by ambient air and the injected fluid. In the process of going from a liquid to a gas in the plumbing system and cylinder the gas expands almost 800%. It's more efficient than current electric cars. This system also eliminates the problems electric cars have. Liquid air is not under pressure so it can be pumped into a tank the same way you pump gasoline into your car. That eliminates heavy, toxic batteries and the time it takes to recharge them. Filling stations will simply use the air around the station to produce Liquid air so only electricity is required to produce it. Also don't forget the large temperature differential   involved. Liquid air changes to a gas at about -77 degrees so even winter  temperatures in areas below the arctic circles will allow the engine to function properly. I've become very fascinated with this concept.



I don't think you understand the theory of heat engines.  Their efficiency is determined by the high and low temperatures they operate between.  A normal steam engine's efficiency is determined by the steam temperature and the condenser temperature.  The reason internal combustion engines are more efficient is that they operate between a much greater temperature difference.  They can do this because the intermittent explosions allow the waste heat to be dissipated between cycles.  This is unlike steam and Stirling engines that have continuous heat input and require serious heat resistant metals to operate at efficient temperatures

This is a steam engine that operates between a moderate temperature and the temperature of the liquid nitrogen.  That's a much smaller difference than an internal combustion engine operates with.  I see its uses in recovering waste heat and similar low temperature difference applications.  The efficiency may be low, but it's not zero.  The most common device for recovering waste heat from internal combustion engines is the turbocharger.

Lohring Miller


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