The engine is a contradiction.

When working, the engine needs a certain amount of heat, such as the cylinder, only a certain amount of heat can complete a perfect combustion, and the compression-ignition diesel engine needs a very high temperature.

However, high temperature will bring problems to other devices, take the most basic cylinder and piston as an example, high temperature will expand, after expansion will cause the piston and cylinder to freeze, continue to move is to pull the cylinder, as long as the engine is high, pull the cylinder is 100% of the things that will happen.

What if you start with a larger gap? When the temperature is not enough, it will lead to insufficient air tightness, and the air and fuel inside the cylinder will pass through the sealing ring on the piston, enter the bottom, and flow into the oil shell, and the result is an increase in oil.

The engine needs a certain amount of heat dissipation, and this heat dissipation, at the beginning, is air-cooled.

Just like the engine of a motorcycle, there are a large number of radiators on the cylinder wall and cylinder head, and in the process of engine operation, the heat is dissipated through these radiator-like radiators, and cooled with the help of the power of the wind, which is called air cooling.

When the motorcycle starts, there will be wind, and when it stops, it will inevitably pull the cylinder if it runs at high speed for a long time.

Air cooling, for a long time, has been the mainstream, because the structure is simple.

The current Deutz diesel engine is also air-cooled, although there is nothing to see from the outside, the huge fan in front of it actively blows a large amount of air into the interior, and the cylinders inside are all with heat sinks, so as to force cooling.

During World War II, it can be said that it was an era when air-cooled and water-cooled engines coexisted, and many cars also used air-cooled engines, but after that, more and more vehicles began to be water-cooled.

The so-called water cooling, there is no heat sink outside the engine, but there is a water jacket, which has been made when the cylinder block is cast, and when the engine is running, there is water circulating in it, constantly taking away the heat, and then the water evaporates the heat through the heat dissipation tank in front of the engine.

Compared with air cooling, the device of water cooling is obviously more complex, so at the beginning, air cooling occupied the mainstream, after all, it was simple, but now, water cooling has long occupied an absolute dominant position.

Mia looked at Qin Zhenhua unmoved, and continued to introduce there: "You can take a look, the engines on the civilian market now are all water-cooled, air-cooled engines, which are already outdated products, after all, it has many shortcomings that cannot be overcome, and the shortcomings of water cooling are slowly being overcome." ”

"I know." Qin Zhenhua said: "Air cooling is not as good as water cooling, the heat dissipation is uneven, and the temperature is not easy to control. ”

Air cooling is dependent on the flow of air, which has a lot of limitations, such as in summer, in desert areas, the outside air is hot enough, let it dissipate heat to the engine, of course, the efficiency will be low.

At the same time, no matter how air cooling dissipates heat, the contact area can never be compared with water cooling, so the efficiency is low. In particular, after the turbocharge, the air-cooled heat dissipation is even more difficult.

At the same time, the air cooling heat dissipation, is to look at the outside situation, they are not easy to control, the speed of the car is fast, the outside temperature is low, the heat dissipation is strong, vice versa, the engine temperature can not be accurately controlled, it is not conducive to the accurate combustion of the engine.

Moreover, air cooling requires a large distance between the cylinders, so that they can not interfere with each other, and there is no wrapping of water jackets and other components, and all the internal noise is transmitted, resulting in a lot of noise.

These are the disadvantages of air cooling.

"yes." Mia said on the side: "Now, various engine factories are developing new coolant, this coolant can not freeze at low temperatures, the boiling point is higher than water, in the future, water-cooled engines, there is no need to put water every day, there is no need to care about the cooling water, even in the cold weather, it will start like air cooling." ”

The most complicated problem of water cooling is that the water must be discharged in winter, and the water must be heated to preheat the engine when starting, which brings a lot of inconvenience to the operation, but with the development of special coolant, these weaknesses will also be overcome.

At the same time, the boiling point exceeds 110 degrees, which can keep the normal working temperature of the engine at about 100 degrees Celsius, and the temperature is high, and the thermal efficiency of the engine will be improved.

In this way, the driver does not have to worry about the coolant at all, and it is already as convenient as air cooling.

"I know all of this." Qin Zhenhua said: "However, I just like air-cooled engines. ”

"You!" Mia felt like she had said all that in vain, and she wanted to stomp her feet. Isn't this treating other people's kindness as a donkey's liver and lungs?

I still like it, you're so old, do you still learn to talk to girls who are angry?

Qin Zhenhua smiled and didn't say anything else.

That's right, he naturally knows these shortcomings of air-cooled engines, but is there a choice now?

When they were producing Mercedes-Benz cars, they were destined not only to civilian use, but more to put them on the military market, and the army had a special preference for air-cooled engines.

There is such an example in World War II, in aircraft engines, the water-cooled engine, as long as the cooling system is hit and the coolant leaks, the engine will soon be unable to work, but the air-cooled one or two cylinders will be broken, and the others will still work normally.

At the same time, the maximum power of Steyr's WD615 engine is only more than 300 horsepower, and if the Deutz engine can continue to be introduced, the maximum power can reach more than 500 horsepower.

Of course, I don't just use it for cars, when the time comes, all kinds of armored vehicles can be used! It is an eternal truth that the bigger the power reserve, the better.

After all, the first machine factory is now busy improving the potential of its own tank engines, and in other aspects, it really can't take care of it, so it can only rely on other brother factories.

As for Mia, in addition to the position of a friend, there is no need to continue to invest more in this area because of the decline of air-cooled engines, but on the other hand, why is she not thinking about Mercedes-Benz? If the Deutz engine is not qualified, they can export more Mercedes-Benz original engines.

Although he can't live the belly of a gentleman with the heart of a villain like this, if he doesn't even consider Mia's position, isn't he too naïve?