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Vivee=)
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I hear diesel engines are better than gasoline engines. Why is that?
They are more efficent in extracting more of the chemical energy of the fuel - ie more miles per gallon. They can also use lower grade fuels which need less refining and so should be cheaper (they aren't because of taxes).Vivee=) said:I hear diesel engines are better than gasoline engines. Why is that?
brewnog said:Diesel: more efficient, higher torque for lower speeds, no inherent reliance on electricity. Heavier, and have the need for more expensive ignition systems. Very receptive to turbocharging.
NateTG said:Diesel engines do not have more expensive ignition systems, but they do have significantly more expensive fuel injection systems.
Moreover, diesel engines are not intrinsically heavier than otto engines, but, rather, tend to run at higher compression (which is also why they work so well with turbochargers).
True!Ivan Seeking said:Diesels have greater fuel flexibility.
Not true! The first engine Dr. Diesel designed ran on coal dust, but he couldn't make the injection system work reliably, so he tried another alternative fuel: vegetable oil.Ivan Seeking said:The first diesel ran on peanut oil.
mgb_phys said:The diesel engine was invented and first built by an English guy called Stuart.
Fortunately his name didn't catch on or we would be talking about a Turbo-Stuart-Intercooler or Stuart-Dykes.
http://www.ybiofuels.org/bio_fuels/history_diesel.htmlOn February 27, 1892, Diesel filed for a patent at the Imperial Patent Office in Germany. Within a year, he was granted Patent No. 67207 for a "Working Method and Design for Combustion Engines . . .a new efficient, thermal engine." With contracts from Frederick Krupp and other machine manufacturers, Diesel began experimenting and building working models of his engine. In 1893, the first model ran under its own power with 26% efficiency, remarkably more than double the efficiency of the steam engines of his day. Finally, in February of 1897, he ran the "first diesel engine suitable for practical use, which operated at an unbelievable efficiency of 75%.
Diesel demonstrated his engine at the Exhibition Fair in Paris, France in 1898. This engine stood as an example of Diesel's vision because it was fueled by peanut oil - the "original" biodiesel[continued]
perkhouse said:I have 3 diesel vehicles: '01 Jetta TDI, '82 Mercedes, and '86 Isuzu. They all 3 run on high percentages of vegetable oil. The VW has been a vegetarian for almost 20k miles now.
Ivan Seeking said:Is it even possible to get 75% ef... The best modern marine diesels do about 58%.
Nay lad e wer a yorkshire man. Although he lived in Oz and built engines there.perkhouse said:I thought Stuart was an Aussie.
Ivan Seeking;1441050I think the best that I've seen in large generator applications is just over 60%. This was based on fuel consumption rate said:Whoah, 60% is rather impressive! Any chance of a reference please?!
brewnog said:Whoah, 60% is rather impressive! Any chance of a reference please?!
Ivan Seeking said:Fantastic! Do you mix vegey oil with diesel fuel directly?
What is your normal range of ambient temperatures? Do you have trouble starting the engines in cold weather?
mgb_phys said:Nay lad e wer a yorkshire man. Although he lived in Oz and built engines there.
Ivan Seeking said:I did some looking and didn't spot anything yet. I was thinking it was Caterpiller, but they have the 500 hp multi-fuel compatible, diesel turbine [an interesting find]. Their 3125 KVA gen units were only checking out at 42% total efficiency.
http://www.freepatentsonline.com/4644751.htmlAn electrical generating plant of high efficiency utilizes a conventional steam plant powered by a fossil fuel such as coal, gas or oil, in internal integration with a high temperature solid-oxide fuel-cell. In one embodiment, the spent fuel and the wast heat from the fuel-cell of electrochemical action is made directly available to the combustion furnace of the steam plant for thermodynamic extraction. The system can achieve efficiencies up to 65% compared to ordinary steam plants which have an efficiency of about 35%.
Diesel engines are more fuel efficient because they have a higher compression ratio, which means they can extract more energy from the fuel compared to gasoline engines. Additionally, diesel fuel has a higher energy density than gasoline, meaning it contains more energy per gallon. This allows diesel engines to travel further on a single tank of fuel.
Diesel engines produce more torque because they have a longer stroke length, which means the piston travels a longer distance in the cylinder. This allows for more fuel to be burned and more power to be generated. Diesel engines also have a higher compression ratio, which creates more pressure in the cylinders, resulting in a stronger pushing force on the piston.
Diesel engines have a longer lifespan because they operate at a lower RPM (revolutions per minute) compared to gasoline engines. This means they experience less wear and tear on their components. Diesel engines also have a simpler design and use stronger materials, making them more durable and able to withstand higher pressures and temperatures.
It depends on the context. In terms of emissions, diesel engines produce less carbon monoxide but more nitrogen oxides and particulate matter compared to gasoline engines. However, diesel engines have higher fuel efficiency, which means they emit less carbon dioxide, a greenhouse gas. Overall, the environmental impact of diesel engines depends on how they are used and maintained.
Some of the disadvantages of diesel engines include their higher initial cost, heavier weight, and noisier operation. They also require more frequent maintenance, such as changing the fuel and air filters, and may emit more harmful pollutants. Additionally, diesel fuel is not as readily available as gasoline in some areas, making it less convenient for some drivers.