Gallery, Projects and General > The Design Shop

A better diesel engine

<< < (2/8) > >>

Mike K:
Wouldn't a nitrous system be cheaper and simpler?  Are there, in fact, nitrous systems on diesel engines?  :scratch:

Mike

Tinker:
On a diesel, propane injection works much like nitrous does on a gas engine.

arnoldb:
There are some disadvantages to adding enriched gasses (oxygen/NOs etc) to Diesels.  One of the disadvantages of a diesel engine is that it has to be built very strong; you can't use lightweight metals like aluminium for the cylinder blocks and heads, as the high compression at which they run just overpowers the light metals.  Diesels also inherently vibrates a lot more than other types of engines, requiring beefing up to keep material stress down.
 
So if you add the enriched gasses, the engine needs to be built stronger, thus heavier.  For a mobile application, you want an engine as light as possible, as it has to move it's own weight as well as that of the vehicle it is installed in.

It is now common to have turbo charging on diesels - it does not add too much extra pressure to the engine, but adds a lot of power and torque, as well as bringing economy down. I drive a turbo diesel VW Polo - while it is a hoot to drive (LOTS of torque and acceleration) - that big lump of cast iron in the engine bay makes it understeer and oversteer very easily in corners.

For Stationary or ships engines, weight is not that critical, so rather than using special gasses, you just build the engine bigger to use free air. The running costs using special gasses would also be astronomical, making it unfeasible.

Now, I did not spout the above verbal diarrhea without coming with an idea, which might be just as ridiculous  :lol:
 
One thing all internal combustion engines do is produce a lot of heat - a lot of which is wasted in the exhaust gasses (the rest by cooling through the radiator).  Now, if one could turn the exhaust manifold into a boiler, and add a steam cylinder or two to the engine - i.e. a hybrid petrol(or diesel) and steam, that might work.  At cold startup, it would be a full IC engine, until the exhaust manifold(boiler) becomes hot enough to start producing steam, and you can then get extra performance, and thus economy from that.  Obviously, this will only be of use on extended trips in motor cars.  In stationary/marine, and even locomotive engines that run for extended periods of time, there might be a distinct advantage.

Cheers, Arnold

Darren:
The extra weight on the steam side might negate much of the gain?

I've always thought that if the waste heat could be harvested for home heating there may be a colossal advantage.
Of course the practicalities are probably going to sink the idea just about one second after any effort was made to pursue.

arnoldb:

--- Quote from: Darren on September 05, 2009, 05:43:05 AM ---The extra weight on the steam side might negate much of the gain?

--- End quote ---

Yes and no... Very little development on steam engines has been going on - mostly just on turbines.  Some of the new materials available on the market could make very powerful, yet lightweight steam engines.  A "plastic" engine with e.g. carbon fiber linkages and rods is not far fetched; many "plastics" can withstand the temperatures, and you don't have the issue of having to cope with explosions and corrosive gasses. One might even get away with a self-lubricating engine, requiring no oil.  This would suit automotive needs.  As to stationery/marine/locomotive engines, they don't care too much about the weight; in the case of marine and locomotive, sometimes additional weight is welcome, as long as there is an increase in power as well - for marine as ballast, and for locomotive to give additional traction.

It's also interesting to note how people think differently about heating and cooling in different parts of the world :D...  Driving through town here in Windhoek this morning, the temperature was already up to 29 deg C - and our spring has just started.  Like Darren said - people in the UK think about heating, whereas we here in Namibia think cooling - we have 3 coldish months in the year, the rest of the time daytime temperatures remain pretty much above 30 deg C...  Now if only I can figure out an effective way to use the sun to cool down my workshop....

Cheers, Arnold

Navigation

[0] Message Index

[#] Next page

[*] Previous page