A possibly cobber tube filled with regular water is drawn around the entire (or less) length of the ICE exhaust system.
The water is supplied to the coil by just gravity, from a tank of say 20-30 liters (10 gallons) at the rear part of the car/vehicle.
The water is heated, at steady-state high way speeds, from the exhasut heat, and propels naturally towards to front of the vehicle, to the engine compartment, where it takes the flash heat from the headers, also.
The water, now low pressure steam, at 200 - 400 degrees celcius, is sprayed into the intake manifold, where the energy/enthalpy/enthropy, is joined up with the regular intake air.
This decreases the temperature difference losses in the regular four-stroke ICE cycle, in that both the intake air flow is pre-heated, and possibly, safely, the gasoline intake flow is heated also.
This allows the burning at higher inlet/initial temperatures, saving heat lost in the moment of combustion, exchanged otherwise at highly inefficient turbulent conditions.
The potential saving is the about 30 % energy lost to exhaust heat, turned into temperauture increases in the intake flows.-- sirau, Jun 02 2011 How engines work http://estore.ricar...roduct.asp?P_ID=149The definitive work on the subject. [Twizz, Jun 02 2011] People tried it. It didn't do any good. http://www.metrompg.../posts/wai-test.htmThese people are pretty hardened. Modern EFI is already compensating for IAT. [WcW, Jun 02 2011] Cyclone engine http://www.cyclonepower.com/Serious heat recovery [Twizz, Jun 03 2011] State-of-Product's in production, at Ford. 2011. http://www.gizmag.c...der-ecoboost/18814/1000 cc 4-stroke turbo-engine, 3-cylinder's, simplyfied. [sirau, Jun 06 2011] Ambient pressure, and even temperature process,, hydrogen. http://www.gizmag.c...ogen-ethanol/18755/- a slight spray additionally,, and wow, there she goes,,..s. [sirau, Jun 06 2011] //temperature difference losses// ?? Engines are powered by the difference between intake temperature and combustion temperature. Cold air good, hot air bad.
If you injected 200 - 400ºC pressurised _liquid_ water into the cylinders then you might do some good (especially using a 6-stroke cycle), but allowing it to expand to steam and mix with the intake air outside of the cylinder is worse than useless.-- spidermother, Jun 02 2011 temperature : It would even out pressures, so the throtle could be wide open, lessening the pumping losses (not pulling the vacuum, at cruising speeds).
It's not the temperature profiles, that generates power (temperature can only be lost, never recovered), it's the pressure on the mechanicals, that is productive, and generates forward motion.-- sirau, Jun 02 2011 NASCAR could use this-- as an overly-complicated horsepower-reduction alternative to the intake restrictor plate.-- Alterother, Jun 02 2011 sirau this is embarrassing.-- WcW, Jun 02 2011 [+]
We precool air to get more power because it allows more air into the cylinder, but what about when the application is for *less* power ?
Why not preheat the air for when you're just tooling around town ? or using a constant 20HP on the highway. Then you get *less* air into the cylinder to match up with the less fuel... on purpose.
(Not sure about the steam bit though)-- FlyingToaster, Jun 02 2011 and less efficiency. why?-- WcW, Jun 02 2011 //why?// Because you can play with the fuel:air ratio. Why would you say it's less efficient ? ; for starters you're not pumping around that much more dead weight.-- FlyingToaster, Jun 02 2011 we already have a way to change the a/f ratio.
Generally speaking, all other things being equal, the ratio between the low and the high side, up to the ratios discovered by Carnot, is a measure of efficiency; higher is better.-- WcW, Jun 02 2011 umm... okay... then the homework for the day is to find out if preheating the air results in a higher or lower temperature of combustion, thus a greater or smaller difference to ambient.
Bear in mind I'm just focusing on the times when you don't want a full 200HP out of your engine so the cylinders at that time are too big for the application... so you don't fill them up as much, by using heated air instead of ambient or cooled.-- FlyingToaster, Jun 02 2011 This could be used as an ejector/injector to introduce additional air at high load, or make up for some throttling losses at part load. However, the gain would have to be set against the losses involved with heating the inlet air.
So long as you managed to use a small volume of steam at very high pressure compared to the inlet air flow this might give a benefit. Bear in mind though that there isn't that much heat in the exhaust when cruising under part load.
This will also increase the thermal capacity within the cobustion chamber, leading to improved NOx emissions but lower exhaust temperatures (which you're relying on for your heat source).
Overall: Probably a very complicated and difficult to develop system with minimal gains (unless it turns out to be a terrific new method of boosting!).-- Skrewloose, Jun 02 2011 just to point out : it's a way to reduce heat losses, that's it !!, and thereby increase efficiency, at regular high-way cruising, where not much power is needed (in relation to the maximum power available, used for accelleration, hills, towing, and other).
The heat recovered from the exhaust, is utilized to :
1. Pre-heat intake air flow,
(at stochionmetric, the intake air mass flow is 14- 16 times that of the fuel flow, ie. burn one kilo of fuel, and you'll need approx. 15 kilo's of air, eg. one to four kilo's of intake charge, per kilometer)
2. Heat the fuel safely, as to a level below self- igniting, to gain the energy/work/power flow of the vaporisation heat/energy, of the liquid-to- gaseous phase of the fuel.
This can easily be looked up, as the difference between 'lower heat value' and 'higher heat value', in a Kilo Joule per Kilogramme terms unit figure.
In a formal energy cycle diagram, like the carnot cycle referenced, this exhaust energy recycling will appear as a incirculation of an energy/power area below the Otto-cycle incirculation.
Something that could be grasped as a :
'thermal laminar flow liquid stationary zero- pressure 'turbo' charger efficiency cycle' -
(TLFSZ-PTCEC), :-)
equipment addition to the very advanced and refined Internal Combustion Engine technology, already on the market.
('turbo' referring to the 'rotation' of the energy (flow), or really : heat 'cycling', or 'recuperating').
When I studied Automotive Engineering, (in Leeds, The North, England), there was a real world investigation result of consumers's car's energy efficiency :
Only 12 % efficiency was the average result, for a gasoline fueled ICE, lumpering about in the real world.
Another rule of thumb, is that at least 30 % of the latent heat energy of the fuel in ICE's, goes lost through the exhaust gasses.
Taken from these figures alone :
If 12 % is utilized, and 30 % additionally is recuperated, then the efficiency goes to :
42 % !,
four times up, !!. (That's the potential, roughly calculated).-- sirau, Jun 02 2011 omfg even the logic of the math is ridiculous. how do you account for the fact that this principal of thermodynamics has gone unnoticed for hundreds of years? Why not simply pipe 100% of the exhaust heat back into the intake?-- WcW, Jun 02 2011 [WcW]:
The '30%' is the entire (your '100%') exhaust heat.
Therefore, not all (less than 100%) of the 30 % heat otherwise lost to the exhaust flow can be recovered, nothings that perfect,.
There will be the flow of kinetic energy still, ie. mass flow times velocity (not velocity squared,.), since the gasses shall and must be evacuated/gotten rid off.
There will be residual temperature between the exhaust gas, after having transfered most of it's temperature/heat to the transfer water/steam tubing, towards the ambient temperature (at which the water at the inlet of the tube is thought to be at). This heat is still lost.
The calculation is of course a provocation, but it's a perspective of the proportions involved.
@ history :
the in his time respected and inside-industry well known Mr. Smokey Younick, Texas I think, worked on recovering exhaust heat, with a sponsored Pontiac Fiero 4-cylinder 2.5 liter car and engine.
His take on it, was to heat the intake air in two- three stages : to 100-120 degrees C in an outside cooling water plenum under the standard carburetor, and leading the intake flow around the outside of the standard cast exhaust manifold, taking the incoming air-fuel charge to 200-220 degrees C, with a presumably standard turbo- charger compressor/turbine in between, with the dual function of mechanically evening out/equalizing the air-fuel charge, vaporizing all micro-scopic droplets fully, and functioning as a 'active back-flow valve', keeping the charge under pressure, under the otherwise expanding conditions of the heating (pre-heating, before combustion).
Mr. Younicks results were good : 1 HP per cubic inch, = 100 HP per liter, ie. 250 HP, and equivalent, reliable, flat, torque curve.
It was a four page featured article in 'Hot Rod Magazine', way back in 1987 (the issue with a Bright Orange rebuilt Chevrolet 1957 'Bel-Air' on the cover.).
I have sent a copy of the Hot Rod article to the engine efficiency responsible engineer, at Alfa Romeo's research center, in Arese, near Rho/Milan, in the region of Lombardia, Italy. I haven't seen any direct application of such temperature, or equalization of droplets, in their market supply. They have their 'cylinder direct fuel injection' system, also used at Ferrari, I gather inspired by develoments in materials for injector tips, in the diesel technology. But, Alfa and Ferrari consumers are not that hung up on effiency, they like outright power, :-).-- sirau, Jun 03 2011 //keeping the charge under pressure, under the otherwise expanding conditions of the heating// That makes a big difference; the expanding heated inlet air is then able to do work against the pistons.
In your idea, all the work is done against the atmosphere, and therefore wasted. In addition, less work is able to be done inside the cylinder, as the pre-heated air is not able to expand as much (the amount of expansion is proportional to the ratio of absolute temperature, not the difference in temperatures). That's why I think it will be worse than useless.-- spidermother, Jun 03 2011 as noted before : it's the mechanical power that is needed/produced, the termal parts of the cycles involved are there to facilitate the pressures, giving the mechanical power.
If you would care to see it in this perspective :
Then the entire temperature increase, from ambient to combustion chamber internal/medium temperature, is all a loss of energy (!!!!!!). A complete loss (seen by observing that the temperature/heat is eventually discharded/lost, out the exhaust pipe).
Therefore, if the inlet air-stream temperature is raised, by re-cycling exhaust heat, the waste is less.
So, in numbers :
Inlet before modification : 20 degrees C (293 Kelvin), ambient temperature
Combustion chamber median temperature : ?? = 1000 degrees C (1.273 Kelvin)
Exhaust final outlet pipe end temperature : 100 degrees C (373 Kelvin)
Inlet after modification : 200 degrees C (573 Kelvin)
Combustion chamber median : 1.200 degrees C (1.573 Kelvin)
Exhaust outlet pipe temp. : 60 degrees C (333 Kelvin)
The Otto four stroke power cycle diagram is unchanged in vertical and horizontal aspects, only it is moved, say 200 degrees C, up, the incircled area, and hence the energy and power produced, is the same.
But an additional power cycle incirculation is to be included : the energy saving 20 degrees to 200 degrees inlet air flow raised temperature ! + Plus the phase transition of the heating of the fuel, from liquid to gaseous form.
I would like to run some more specific numbers, but it's the specific heat of atmospheric air, at a process from 20 to 200 degrees Celsius, x times a mass proportion of 15 (stochiometric), plus the specific heat of gasoline, also from 20 to 200 degrees Celsius, x times a mass proportion of 1 (one), + plus the mass specific difference between 'lower heat value' and 'higher heat value' of gasoline, x times 1 (one) mass proportion, also,,,,,, these three added together, and then the total, divided by x 1 (one) mass proportion x times the average heat value, achieved in combustion by the before- modification configuration (manufacturers and oil companies uses the lower heat value, normally, as a reference).
At this time, I cannot even guess at the results of such a detailed calculation. This would evaluate the potential and scope of the suggested addition to cars, fairly, and accurately.-- sirau, Jun 03 2011 Royalty/license fee claim : 10 % of material costs, 1,0 % of projected first 10.000 kilometers fuel costs saved, by entire applied sold fleet of vehicles,. :- ))))).-- sirau, Jun 03 2011 The exit remark from the Hot Rod article, as to what was next to be expected, from/by Mr. Smokey Younick, was that he would be looking into Ceramic Materials, for the involved mechanical parts. This to increase operating temperatures, safely, as the ceramics will stand up to 1.400 - 1.800 degrees Celsius, without deteriorating, physically/chemically.
The article stated that his engines were operating at 80 % effiency, and that with ceramic components, closer to 100 % (!!), should be expected.-- sirau, Jun 03 2011 Sirau - seriously, read Ricardo or any other work on heat engines.
Exhaust gas heat is not entirely wasted in modern engines. Cooling the exhaust increases the gas density and reduces it's velocity, also reducing extraction effects.
While it is true that there is some energy which could be recovered, in a motor car it is not practical because the size and mass of the recovery equipment outweighs the benefits.
For some serious efforts in heat recovery, take a look at the Cyclone engine (not and IC engine). This guy has achieved over 32% effecicency (that's 32% of fuel energy converted to mechanical output at the shaft) which exceeds the best modern diesels.-- Twizz, Jun 03 2011 I will present the detailed numbers some day.
A prototype even, if the calc is favourable.
15 meters of coiled up thin-walled cobber tubing will be less than 3 kilo's, and an additional cost to consumers of say 100-200 USD/EUR, completely and fully engineered, and installed on the assembly line (an additional feature/work off-line, done by the exhaust system manufacturer).-- sirau, Jun 03 2011 I had a look at the Cyclone page : 3200 psi's pressure is equal to 230 atm,,. Could possibly be increased, to increase power-work-flow to weight/installation space ratio.
And , the Cyclone engine, even if ever so complicated (possibly reduced to the complexity of a refridgeator compressor,..), could be applied in parallel to a regular ICE, feeding off the ICE exhaust heat, instead of burning fuel inside itself.-- sirau, Jun 03 2011 {omfg}-- WcW, Jun 04 2011 On GIZMAG link :
A two stroke could yield the same enrgy/force profile, at 30 % less material take-off, and lugging- about installed weight. With direct fuel injection, and newest materials, higher rev's and wider power band possibly also. Two stroke with Turbo, and ceramics from plasma spraying onto cheeper metal parts. For long distances, an steam energy transfer exhaust-to-inlet air energy exchange, would decrease lower- to -higher- specific burn- heat value, and elevate peak process temperature of the individual 'inlet charge' batches, also incresing efficiency, inherently.-- sirau, Jun 06 2011 Hydrogen link :
A 12-13 kilo's added weight, and it's a bi-fuel (tri- including water/steam :-) ), solar ray surface on roof, reactor canister in the lowest part's.-- sirau, Jun 06 2011 random, halfbakery