Talk about grasping at straws. The most efficient conversion would be at the highest temperature. It is , after all, a HEAT engine. Unfortunately we have no commercial materials that can withstand a stoichiometric mix. An engine run with a stoichiometric mix first burns the exhaust valves and if it runs long enough devours the pistons as well. Hitlers boys researched an engine that ran red hot but never got it out of the lab. The best practical engine I know of is a Bourke. The Experimental Aircraft Association had and perhaps still publishes a paper about it. Had 50:1 compression for those that understand why. Kirk
Mike Pelly <[EMAIL PROTECTED]> wrote: -----Original Message----- From: Mike Pelly [mailto:[EMAIL PROTECTED] Sent: Monday, April 28, 2008 11:41 PM To: 'sustainablelorgbiofuel@sustainablelists.org' Subject: RE: [Biofuel] Vaporized gasoline engines workasproventotheworldbyShell Oil Company in 1973 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Zeke Yewdall Sent: Monday, April 28, 2008 11:50 AM To: sustainablelorgbiofuel@sustainablelists.org Subject: Re: [Biofuel] Vaporized gasoline engines workasproventotheworldbyShell Oil Company in 1973 A good ICE engine might turn one third of the input energy to mechanical energy, one third to heat rejected to the water jacket, and one third to heat in the exhaust stream. This is a good point, thanks for helping me make my point. If a significant portion of the heat going to the exhaust system and the water jacket instead went to heating up the gasoline in the heat exchanger to a vaporous state, than we now can see where some of the increased work used to increase the vehicles fuel mileage is coming from. It's been a while since I studied the Carnot cycle but am I right in remembering that the closer one can bring the incoming temperature to that of the outgoing temperature, the more efficient the cycle becomes? That is basically what happens when your robbing exhaust heat to heat the gasoline in the heat exchanger/exhaust manifold. The other thing that happens is that the vaporous gasoline has a much easier time mixing with the in coming air in the intake manifold. Far better than liquid gasoline sprayed in at ambient temperatures. If we use a 100kW (mechanical) engine (about 130HP), that means that it is also giving out 100kW of heat to the exhaust, and 100kW to the cooling water. Would that not mean it is now a 300kW?3 times 100? If it is indeed possible to double the efficiency of the engine by burning unburned hydrocarbons, then we must assume that we have 100kW of energy in unburned hydrocarbons leaving the tailpipe as well. If all of that is burned in the catalytic converter, it would have to dissipate 100kW of heat, or send it off as an even hotter exhaust stream. In addition to the 100kW of waste heat sent off in the exhaust stream already. I just question whether the average cat is capable of dissipating 100kW of heat without getting seriously hot -- not just the 1500F or so that they run, but 4000F or such... Think about a regular stove burner which manages to get to 3,000F with just 1500 watts of heat. I don't have the numbers to prove this though. Z On Mon, Apr 28, 2008 at 12:36 PM, Mike Pelly wrote: > You don't think cats are hot? Put your finger on one sometime and than > let me know what you think. They have shields all over them for a good reason. > They are very efficient at re-burning the hydrocarbon rich exhaust > but why are we not working to improve vehicle fuel effeciency by > burning this fuel properly the first time? > > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On > Behalf Of Zeke Yewdall > > Sent: Monday, April 28, 2008 10:21 AM > To: sustainablelorgbiofuel@sustainablelists.org > Subject: Re: [Biofuel] Vaporized gasoline engines work > > asproventotheworldbyShell Oil Company in 1973 > > > > > The > > biggest problem in their logic is that if the catalytic converter > > really was burning off a large percentage of unburned hydrocarbons > in > the exhaust, it would have to be dissipating enormous amounts > of heat > -- and though they do run hot, they don't dissipate an > equal amount > of heat to the rest of the engine. Therefore, there > simply is not > that much unburned hydrocarbons to double the gas > mileage of a car > simply by increasing the combustion efficiency > (either by hydrogen > injection or gasoline vaporization or whatever). > > > I do not have a clue what point you are trying to make. Can you > take > another stab at this one? > > I think you've just made my point for me. When I bring it up the > first law of thermodynamics as a potential argument for why what you > are proposing won't work, you don't understand it. Unless you can > show me where I've drawn the energy boundries in my model in the > wrong place, I simply don't think it's possible -- if regular > automobiles were sending as much unburned hydrocarbons out the > exhaust as you claim, the catalytic converters would be glowing > bright red all the time (which, in a really out of wack car, they can do, but it's not normal). > > And, as far as high efficiency vehicles go, there was as college > competition not too long ago, that I believe achieved 1700 miles per gallon on gasoline. > For some little carbon fiber pod thing -- again, an impressive stunt, > but not directly applicable to the behemoth automobiles that we drive > around in reality (which as Robert pointed out, it part of the > problem...) > > > _______________________________________________ > Biofuel mailing list > Biofuel@sustainablelists.org > http://sustainablelists.org/mailman/listinfo/sustainablelorgbiofuel > > Biofuel at Journey to Forever: > http://journeytoforever.org/biofuel.html > > Search the combined Biofuel and Biofuels-biz list archives (70,000 > messages): > http://www.mail-archive.com/biofuel@sustainablelists.org/ > > > __________ Information from ESET Smart Security, version of virus > signature > > > database 3060 (20080428) __________ > > The message was checked by ESET Smart Security. > > http://www.eset.com > > > > __________ Information from ESET Smart Security, version of virus > signature database 3060 (20080428) __________ > > The message was checked by ESET Smart Security. > > http://www.eset.com > > > > _______________________________________________ > Biofuel mailing list > Biofuel@sustainablelists.org > http://sustainablelists.org/mailman/listinfo/sustainablelorgbiofuel > > Biofuel at Journey to Forever: > http://journeytoforever.org/biofuel.html > > Search the combined Biofuel and Biofuels-biz list archives (70,000 messages): > http://www.mail-archive.com/biofuel@sustainablelists.org/ > _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/sustainablelorgbiofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (70,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/ __________ Information from ESET Smart Security, version of virus signature database 3060 (20080428) __________ The message was checked by ESET Smart Security. http://www.eset.com _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/sustainablelorgbiofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (70,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/ --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! 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