During the autumn harvest of 1502, Marin was in the wheat field and commissioned Leonardo da Vinci to develop a steam engine. At that time, Marin casually drew a schematic diagram www.biquge.info of a steam engine, gave it to Ada, and left it alone.

Now, more than a year later, Marin just remembered that the Tara lead-zinc mine is up to 50 meters deep and may need to be pumped. Therefore, Leonardo da Vinci's steam engine is very important.

In any case, mechanical pumping is much faster than human pumping, even with the lowest steam engines. In fact, in the early days, in the late 17th and early 18th centuries, the steam engine was used to pump water from coal mines, and had no other purpose.

It wasn't until later that Watt improved the Newcomen steam engine and used a separate condenser and circulation system to reduce water consumption. Moreover, a set of "sun and planet" crank gear transmission system was also developed, which converted the reciprocating motion of the steam engine into rotational motion, laying the foundation for the steam engine to become a power engine......

"Oops, oh no, I didn't give Ada a drawing of the 'Sun and Planets' crank-gear system, no wonder he hasn't produced results yet......" Marin patted his head in regret, remembering that he had forgotten to draw Da Vinci's transmission system, which is very important for the steam engine, which converts reciprocating motion into rotational motion.

Leonardo da Vinci, no matter how clever he was, was only a man from the mid-15th century to the early 16th century. Because of the ideological constraints of the Holy See, he did not dare to exchange advanced scientific knowledge with others, and some of them worked behind closed doors, and he may not be able to come up with this transmission system.

At that time, because Marin had a lot of things to do, and he wanted to fight with Denmark, the schematic diagram of the steam engine he drew casually was the most primitive single-cylinder vertical steam engine. Moreover, only the part of the steam engine block is drawn and the principle of piston movement is briefly annotated. The rest, not covered. It is estimated that there are Ada troubles.

Sure enough, when Marlin arrived at Leonardo da Vinci's laboratory, he saw a very earthy steam engine swaying up and down, and it was swinging up and down very slowly. As for what crank gear drivetrain, that's no.

Leonardo da Vinci was frowning, thinking about how to make the steam engine run faster. Because, at the beginning, Marin told him that he wanted to make the machine turn, and it would run very fast.

This is also a problem with Marin's understanding, in fact, in modern times, whether it is an electrical appliance or an internal combustion engine, the speed of rotation is very fast.

However, in the early days of the steam engine, the steam engine was very slow. The steam engine invented by Watt was much more efficient than the Newcomen steam engine, but the speed was only forty or fifty revolutions per minute. In the modern era before Marin crossed, an electric fan could turn 500 to 1500 revolutions per minute casually, which was completely incomparable. Even at the beginning of the 20th century, steam engines rotated at 100 to 300 revolutions per minute. So, it was Marin who was demanding, not that Leonardo da Vinci didn't do it well enough.

Then, Leonardo da Vinci explained to Marin in detail the structure and principle of the steam engine he had made......

The principle of this steam engine is very simple, that is, the bottom boiler, the steam burned, straight up. When the steam reaches a certain concentration and forms a certain air pressure, it will break through a movable valve at the top, enter the cylinder above, and push the piston pressed at the bottom to the top.

When the piston is pushed to a certain height, there is an opening in the side of the cylinder to allow the high-pressure steam to leak out. In this way, the air pressure in the cylinder is vented all at once. Under gravity, the piston falls back. At the same time, the valve between the boiler and the cylinder closes.

By falling the piston together, one end of a balance rod attached to the top of the piston will be driven by the piston, so that a wooden rod at the other end will move up and down. Of course, with Watt's invention of the "Sun and Planets" crank gear transmission system, this connecting rod will not move up and down in a straight line, but will drive a wheel to rotate through the transmission system.

In addition, because when the piston rises to the top, there is an opening to release all the steam. And water vapor is formed by the vaporization of water. As a result, the water in the boiler also decreases with the release of water vapor. If you don't replenish the water, you may dry the boiler and explode.

Therefore, Leonardo da Vinci designed a water supply system on the side of the bottom of the cylinder. There is also a movable valve in the pipes of this water supply system. Moreover, the water container of the water supply system, which is set higher, has a certain water pressure. When the pressure in the cylinder is high, the valve of the feed water system is closed. However, when the piston is raised to the highest level, the air pressure in the cylinder suddenly decreases dramatically when the steam in the cylinder is suddenly released. At this time, the water pressure of the feed system exceeds the air pressure of the cylinder, and then, when the valve is loosened, a small amount of water will be sprayed into the cylinder, and then the piston will be pressed into the boiler, which is considered to be added water.

After listening to the introduction of the whole structure, Marin realized that it was a Newcomen steam engine......

Although, the design is really ingenious. However, there is a problem that you can't add water to the boiler, but you can't actually add it to it. Because, the steam in the boiler is formed by the surface of the water. Adding water from above will inevitably reduce the temperature of the surface of the water layer in the boiler, affecting the generation of steam.

Therefore, Marin remembers that the steam circulation system of later generations was generally located under the side of the boiler to add water to the boiler. In this way, the temperature of the uppermost layer of water in the boiler is not lowered, and the large amount of water vapor generation is not affected.

The disadvantage of the Newcomen steam engine is this, adding water from above will reduce the temperature of the surface hot water, reducing the generation of water vapor. As a result, the amount of water vapor in the steam engine is affected, and both power and operating speed are reduced.

Later, adding water from the bottom of the side can not only avoid the problem of surface water temperature dropping. In addition, cold water is added to the lower part of the combustion chamber and is heated more quickly.

"Yes, the water vapor circulation system ......" Marlin patted his head, remembering what the shortcomings of this steam engine were.

The most important thing for Watt to transform the Newcomen steam engine is two points - the first is to add the "sun and planets" crank gear transmission system, so that the operation of the steam engine has been transformed from reciprocating motion to practical rotation; The second is the addition of a water circulation system with a separate condenser.

When the water vapor at the top of the steam engine leaks out, it is not discharged directly into the air, but through a pipe, into a condenser surrounded by cold water. In order to increase the cooling contact area, the pipes soaked in condenser water are generally designed to be curved to enhance the condensation effect of the condenser. Moreover, the water in the condenser is often replaced. Once it's hot, switch to cold water. Moreover, the condensation water is not very demanding, any water can be used, and seawater is also formed. Unlike boiler water, clean fresh water is generally used to prevent fouling from affecting efficiency.

After the water vapor condenses into water in the condenser, it will pass through a pipe to the lower side of the boiler, and the cooled water will be sent into the boiler to form a circulation. In this way, the water in the boiler is basically not consumed. And the boiler, there is no need to add water from the outside frequently. After all, adding water from the outside can easily cool down the hot boiler and affect the efficiency of the steam engine.

However, it does not mean that with this condensation circulation system, there is no need to add water. Because, the piston of the cylinder is not 100% sealed. When the work is done, a small amount of steam will escape from the gap between the cylinder and the piston.

So, even with a condensing circulation system. After a while, the boiler still has to add water from the outside. Just like the old green train, when it comes to the station, it often has to add water. The boiler water should be added, and the cooling water should also be added.

Therefore, in order to prevent the boiler from exploding, the side wall of the boiler generally uses high-temperature resistant glass or other instruments to display the water level in the boiler. Once the water level in the boiler has dropped to a dangerous level, in order to prevent an explosion, it is necessary to temporarily shut down and fill up the boiler with water.

Marin told Leonardo da Vinci about two important improvements to the Watt steam engine that his physics teacher had told him in junior high school, and he made Da Vinci stupid. Then the old man looked up to the sky and sighed:

"The old man always thought that he was the smartest person in the world, but I didn't expect that the guy named Watt was actually even better than the old man......" said Da Vinci's eyes moistened. Obviously, the goods have been hit.

Marin couldn't help but laugh and said to Leonardo da Vinci:

"Alright, Ada, don't be discouraged. Everyone has their own specialty, and that watt is better than you on the steam engine. You're definitely better than him than drawing! ”

Listening to Marin say this, Da Vinci, who was hit hard, felt better. Then, according to Marin's train of thought, the steam engine was "watted......

However, Marin clearly remembers that there was also a centrifugal governor on the Watt steam engine, which was used to control the speed of the steam engine to be stable.

However, Marin's junior high school physics teacher in his previous life did not teach this principle, so Marin did not understand it either. After all, he didn't graduate from the mechanical department, just a good liberal arts student in physics.

In this way, the speed of the steam engine may be somewhat unstable. But whatever, the steam engine is not very demanding, and the speed is unstable.

But in line with the principle of "doing the best", Marin simply explained to Leonardo da Vinci the principle of a centrifugal governor, which is probably a cone pendulum connected to a steam valve to control the speed of steam output...... Anyway, Marlin left the conundrum to Leonardo da Vinci...... Those who are in power must learn to throw problems to their subordinates...... If you do everything yourself, it will definitely be the end of Zhuge Liang's overwork......

When the watt-type steam engine was introduced, it would be easier to pump water. When the time comes, Marin will take out the Archimedes spiral and make it into a spiral pump, which will be used to pump the groundwater of the Tara lead-zinc mine, which is not too practical......