Why car engine thermal efficiency can not reach 100%

Why can't a car engine reach 100% thermal efficiency?

Why can't automobile engine thermal efficiency reach 100%? When an internal combustion engine is running, the thermal efficiency is constantly changing depending on the status quo! 40% thermal efficiency is only at certain engine speeds and loads, and the average thermal efficiency is only about 35%, which means that about 65% of the heat is lost.

Take a look at how 65% of that heat is consumed and what happens when it isn't! The reason the engines in our cars don't melt is that they actually rely on the cooling system to help dissipate the heat because the outside of the cylinder walls and the outside of the cylinder head are filled with coolant; it removes it quickly.

The combustion chamber and the outside of the cylinder head are so full of coolant that the maximum temperature of the cylinder wall is just over 100 degrees Celsius! But there is no way we can break the bonds of the laws of thermodynamics, from which we derive our internal combustion engines, and it is impossible to break the bonds of the laws of thermodynamics going this way, so there is another paradox here.

That is to say, the internal combustion engine is not completely subordinate to the traditional laws of thermodynamics, and the internal combustion engine future development goal is to break the laws of thermodynamics? It's quite possible to overcome friction and build a perpetual motion machine, where a car may not get a third of the gas mileage, but when boosted, it gets zero gas mileage. Just braking would be enough a few drops of gas running concept could run all day.

Of course, the impact is not only the car, all other industries also have to go through a major modernization, it is no exaggeration to say that this is two different worlds. For the average family car, it's hard to balance thermal efficiency, power and engine life any more, so the more thermally efficient the engine, the better!

If the thermal efficiency of an engine reaches 100%, it means that there is zero friction between the engine piston cylinders, engine crankshaft bearings, ignition coils and other components, and the heat they generate will act on the outside. They give us the experience of 2-3 times more range in the gas tank.

In addition, this engine will no longer need coolant, and its quiet running tends to be zero. With hydrogen fuel injected during the intake stroke, the cylinder cooling system would have to be very advanced. Intake temperatures and cylinder heat dissipation rates are important, and there are other basic technologies that will remain the same, going forward.

Of course, it will start with a mixture of biogas and hydrogen fuel for the internal combustion engine, and then the internal combustion engine itself will produce some hydrogen fuel. Of course, there is still a lot of technology that needs to be innovated in order to fully realize open water technology. If a car engine has a thermal efficiency of 100%, this means that all of the mechanical energy output is converted into energy produced by combustion.

The car could then accelerate to 100 kilometers in milliseconds with virtually zero fuel consumption. It's an indescribable thing. The first thing you can be sure of is that the fuel can't be ordinary heating oil; the thermal efficiency of an ordinary fuel engine is around 70%, which is the theoretical limit.

If it exceeds this limit, it can be said that it is a perpetual motion machine The theoretical limit of nuclear fuel is even higher, and it can reach 99% The fire efficiency of fuel engines can be infinitely close to 100%, while the fire efficiency of nuclear fuel can only reach 20%, and it covers the surface of the spark plugs and pistons, forming carbon deposits, which is the result of incomplete combustion.

The carbon buildup affects the next spark plug and gas explosion. So the gasoline in the car is not 100% burned. Opening the four-stroke exhaust valve releases carbon dioxide and nitrogen oxide particles. That is, after the car has traveled 20,000 kilometers. For replacing spark plugs and dealing with maintenance cylinder carbon buildup.

For example, BYD's recently released Snapdragon engine, with an efficiency of 43 percent, is considered one of the most efficient automotive engines available. The increased efficiency means more work capacity, the ability to travel with the same amount of fuel heat release, and greater work capacity coupled with efficient transmission allows the car to travel longer distances.

The same distance can save fuel. Part of the internal energy of the oil is converted into mechanical kinetic energy and the other part into chaotic energy. Entropy, the conversion of one energy into many, increases. If all of the internal energy of the oil is converted to mechanical kinetic energy, entropy does not increase, so it can never be 100% thermally efficient.

And, if it could be converted 100% losslessly, perpetual motion would be a reality. So that's why thermal efficiency can't be 100% anymore.