Li Zhi returned to Fanjiazhuang and found an independent yard in the cannon workshop as a research place for steam engines.??
The principle of a steam engine is very simple. It uses the expansion pressure of water when it is heated to turn into steam to push the piston, and then uses the vacuum generated when the steam cools into water to move the piston. These two movements are combined to drive the piston.
It is continuously pushed up and down to transmit power to the outside.
In the history of later generations, practical steam engines appeared in the early eighteenth century, just a few decades away from the twelfth year of Chongzhen. One of the more famous ones is the Newcastle steam engine. The principle of this steam engine is very simple, that is
After using the power of steam to push the piston, spray cold water into the cylinder to cool the steam, and let the vacuum generated suck the piston back. By repeating these two movements, it can be driven outward.
Historically, thousands of this simple-structured steam engine were produced and widely used in British coal mines to pump water from the mines. The use of this steam engine helped Britain become the largest coal producer in Europe in the early 18th century.
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Li Zhi had never actually made a steam engine, so he decided to start with the simplest Newcomen steam engine, starting with the easier ones and then the more difficult ones. First make the Newcomen steam engine, and then upgrade it.
But to make a steam engine, the first thing Li Zhi needed to do was a simple lathe. Without a lathe, steel objects could not be finished. Li Zhi had already made a boring machine before, and the structure of the lathe was similar, except that one was a rotary boring tool and the other was a boring machine.
The object to be processed is rotated, but the same thing is that one thing is rotated to grind another thing, and the structure is similar.
Li Zhi guided the blacksmith and spent five days making a simple lathe, using the crucible steel he smelted as a turning tool. The final lathe could only be said to be a primitive lathe, but it was enough for Li Zhi's use.
After the lathe is produced, it can be used to make the piston. Li Zhi first needs to make a cylinder with a diameter of 30 centimeters, cast it from pig iron, and then use a boring machine to finish it. In the boring machine, a cylinder with the same diameter of 30 centimeters must be placed.
The piston. Li Zhi asked the blacksmith to cast it into pig iron and then finish it with a lathe.
After repeated comparisons, processing, comparisons, and reprocessing, Li Zhi finally got two cylinders and pistons that fit perfectly. Li Zhi put the cylinder with the chassis opened on the boiling water and found that the piston was completely airtight.
.Think of it, even if higher pressure water vapor pressure comes in, the air leakage will be very slow.
Li Zhi made a push rod on the piston, which is pushed by the piston moving up and down.
Then there is the cooling device. Li Zhi fixed a cold water bucket next to the piston. The cold water bucket is connected to the bottom of the cylinder. There is a valve at the connection. A mechanism control valve is made at the outermost end of the push rod. If the push rod is pushed up by water vapor,
When it reaches the top, the mechanism is opened, and cold water is sprayed into the cylinder to cool the steam. Once the water vapor cools, the piston drives the push rod to move downward. When it reaches the bottom, it touches the mechanism to close the cold water gate, and so on.
The next step is to make a boiler. This boiler must be large enough to produce enough steam for propulsion. After the boiler is completed and connected to the cylinder, the entire Newcomen steam engine is completed.
Li Zhi spent five days completing each component, screwing the components together, and began to test whether the work was successful.
As soon as the boiler was heated up, Li Zhi found that the entire steam engine was leaking air everywhere. There was not much air leakage between the finely machined piston and cylinder, but the joints of the pipes were screwed together with threads, and the gaps were large. At this time, everywhere
They all sprayed water vapor outside.
However, even if there is air leakage everywhere, the steam engine is still successful. This is because the intensity of the water vapor burned in the boiler is higher than the intensity of the air leakage in the pipes. The water vapor pushes the piston to do work and constantly moves up and down. Because there is air leakage in each pipe, the cylinder
The air pressure inside is just under control, and the up and down movement of the push rod is relatively stable, seven times.
This Newcamen steam engine has finally been built.
However, the efficiency of the Newcamen steam engine is very low. It requires burning a lot of firewood to produce limited thrust. This is because the water vapor in the cylinder is cooled and the cylinder body is also cooled. Then after a while, the hot steam comes in and heats the cylinder body.
, wasting a lot of heat over and over again. Such an inefficient steam engine obviously cannot meet Li Zhi's needs. Li Zhi wants to gradually transform this Newcomen steam engine into a Watt steam engine.
Watt's biggest improvement to the Newcomen steam engine was the condenser. With the condenser, the cylinder block would not be heated and cooled repeatedly.
The condenser is actually a large iron can, connected to the cylinder, with cold water inside. The switch of the condenser is controlled by a mechanism. When the piston is pushed to the top, the switch opens, and the steam enters the condenser and is cooled into water. When the piston falls to the bottom,
, the switch is turned off, and the steam has nowhere to escape and gathers in the cylinder, pushing the piston upward again.
But when making the condenser, Li Zhi discovered that the condenser required higher air pressure than the water spray cooling method. Such high air pressure could not be gathered in the leaking pipes, so he had to find a way to plug the leaking places.
But there is no high-temperature-resistant rubber these days. Li Zhi thought about it and couldn't think of anything that could be used to block the leaking pipes. Li Zhi had no choice but to use softer materials available on the market to test them one by one.
.But I tried all kinds of textiles, but the effect was not good. The silk that looked very smooth and soft became charred and caked when burned by the high-temperature steam. The material that is more resistant to high temperatures is linen, but the pores of linen are smaller.
It's too big and can't block the leaking steam.
After several days of testing, Li Zhi still couldn't find a material that could block the air leakage. Li Zhi was a little stumped. The principle of this Watt-type steam engine is simple, but the details are still very complicated to make, even if one detail is not done.
Well, it can't drive the entire steam engine.
Speaking of which, copper or lead is relatively soft and can withstand high temperatures of hundreds of degrees. Do we need to use copper and lead to make pipe joints? This is very troublesome to do.
A young blacksmith who was transferred by Li Zhi to make a steam engine watched Li Zhi conjuring a Newcomen steam engine these days and admired Li Zhi very much. At this time, when he saw that Li Zhi was encountering a problem, he interrupted and said: "General
Sir, if you soak the linen cloth in oil for a day, the pores inside the linen cloth will be blocked by the oil, and it may be useful."
Li Zhi was stunned for a moment, but he didn't expect that there was such a way.
He patted the young blacksmith's head and followed the blacksmith's method. Wrap oil-soaked linen cloth around the threaded joint, tighten the joint, and restart the steam engine.
At this time, Li Zhi found that there was no air leakage in the pipe.
Li Zhi said to the young blacksmith: "It's a good suggestion. I'll reward you with ten taels of silver!"
The young blacksmith made ten taels of silver just by saying one word. He was so happy that he smiled so much that his mouth almost stretched to the back of his head. 8
