Restarting life in Siheyuan

Chapter 369 Fault Recurrence, Problem Confirmation

"Okay, stop."

Zhu Xuefeng already knew in his mind that the engine could no longer increase the speed without cooling down. This was a diesel engine, and the temperature had a great influence on the compressed mixed air in the cylinder. It might cause the cylinder to explode.

The experiment lasted less than two minutes in total. The temperature of the cylinder did rise a lot, but overall, it was not completely high. After all, the time was too short.

"The time is too short, and the engine temperature has not had time to really rise, which means nothing,"

"It's just that such a short time cannot prove high reliability."

"The cylinder is hot, and the fault has not recurred. What did this experiment prove..."

There was a lot of discussion at the scene, everyone expressed their opinions, and the Navy representative came over.

"Comrade Xiao Zhu, what exactly did your experiment prove? I'm very curious about what conclusion you came to. Can you share it with everyone?"

"Representative Niu, I have a preliminary conclusion, and I still need to discuss it with the seniors."

"Please also express your opinion."

At this time, Director Zhao also hurried back with his people. They checked the entire casting process and found that there were no major problems.

Faced with doubts, Zhu Xuefeng said with a smile. "You are right to say that. It can still run normally at 7000 rpm. There should be no problem with the cooperation."

There was a lot of discussion below. There are many methods of analysis. I have never seen it so straightforward. It is indeed like a tree, and it is also like a fish bone with its flesh removed. This is a good method. This way the logic is indeed clearer, more organized, and not easy. Missing relevant possibilities.

"Regarding this, I would like to explain three issues. Through measurement, the dimensional deviations of the cylinder and piston are slightly larger than the design requirements."

Finally, a release form was found, and the factory admitted that the accuracy was a little worse than the drawing requirements. The designer and the military both recognized it after passing the review and signed the "Super Tolerance Substitute Release Form."

"This diagram, I call it a fault tree, also called a fishbone diagram. This is the fault. Let's analyze the reasons for holding the tank..."

"Senior, our analysis is not over yet. Please listen to see if this possibility exists."

"Please tell me if you have something to say."

Zhu Xuefeng nodded and pointed at the designer who was eager to explain.

The designer still couldn't understand, "But our previous matching dimensions were always like this, and we have verified them many times, so why is there no problem."

A blackboard was set up at the experiment site, and Zhu Xuefeng drew an inverted tree branch on the blackboard according to his own sketch.

"Seniors and experts, I have some ideas here. I'm just trying to show off my embarrassment here. I hope you won't laugh at me."

"So your final suspicion is still the cooperation between the cylinder and the piston. Although your verification this time is strange, it seems that you have also verified that the cooperation is OK."

"This time the designer's accuracy requirements have improved a lot. This time we also used your factory's technology in production, and the accuracy has also improved a lot. It should be better than the previous engine, although it is a little worse than the designer's requirements. This This is also the highest accuracy our factory has achieved in recent years.”

The military also nodded. They signed the agreement after discussing the concession and release before they could start the next step.

"Their accuracy is the highest, which is much better than before, so we signed a concession and released it. We just followed your factory's accuracy requirements. Even if they didn't meet it, we don't think this is the reason."

"What does it mean? There should be no problem. Many engines have this matching size, so there should be no problem."

Looking at the factory personnel raising their hands below, Zhu Xuefeng still gestured politely despite being interrupted.

"There is no problem with the normal size. When the engine block temperature rises and the water cooling system starts to work, the heat dissipation effects of the cylinder block and the piston are inconsistent, causing the piston to get stuck!"

The designer did not agree with Zhu Xuefeng's terminology and pointed it out on the spot.

Zhu Xuefeng retracted his hand, "I also agree with you. This is not the root cause. Through measurements, I know that the piston has a negative tolerance. This error will cause a slight decrease in engine power and will not cause cylinder locking."

"Let's talk about another issue. Previous engines have not reached such a high speed, and the friction heat was underestimated. This also has a certain impact."

No one objected now, Zhu Xuefeng continued.

"I think there is a problem with the design of the fit size. The material used this time is a new material, and the expansion coefficient is slightly different from the previous cast iron. Using mature fit size is a hidden danger at this time."

"It is not obvious when the temperature is not high. The rotation speed continues to increase and the temperature changes sharply. Then the temperature of the cylinder and the piston is inconsistent due to water cooling, and the problem arises. I don't know if all the seniors and experts agree with me..."

It became quiet all of a sudden. Everyone is a leader in the industry. A difference in expansion coefficient explains everything. This experiment indeed proved that when the temperature is the same, there is no big problem. When the temperature difference occurs, a fault will definitely occur.

After a while of discussion, applause slowly broke out and gradually became louder and louder. Unexpectedly, it was the change in the material that caused the expansion coefficient to be different. The size that did not cause problems before was now inappropriate.

"Of course, this is just our current judgment. Whether it is a problem with heat dissipation and size coordination, I think we should verify it with another test run."

"Didn't you verify it just now?"

Zhu Xuefeng shook his head, "This speed has only reached 7,000 rpm, which is far from the designer's requirements. The cylinder has been damaged just now and is not suitable for high-speed experiments. Didn't we make three sets at one time? Those two sets are just here. Do comparative experiments.”

Everyone in the party feels a little distressed. This one requires a lot of money. If we try two more, everyone will feel distressed.

"Representative Niu, those two units should be the same as this one. They cannot be put into normal use. Although they have not been tested yet, they must be considered waste products."

Although Zhu Xuefeng's words were harsh, but thinking about it, they could only be trash. Representative Niu nodded.

"Then let's try it according to the experimental plan of the steel rolling mill to ensure that we find the problem accurately."

The two engines were placed far apart, more than 20 meters apart, to avoid accidents.

"According to the plan, it starts directly from 5000 rpm, each speed lasts for ten seconds, and changes once every rpm. The No. unit does not need water cooling for heat dissipation, and the No. unit uses water cooling for heat dissipation."

The speed quickly reached 7,000 rpm again, and surprisingly, none of the cylinders were locked.

"Rise to 8000 rpm."

Zhu Xuefeng had been staring at the hot piston carefully. There was an exclamation from outside. It was too dangerous. He was surprised that there was no lockup just now. Now an accident occurred. The No. 8000 engine was still running normally at 7000 rpm. The No. engine was forced to shut down after holding on at rpm for a few seconds. A cylinder lock occurred and the fault recurred.

"Rise to 9000 rpm, hold for one minute, and shut down."

The accident occurred again, and the No. 9000 machine was still working normally at rpm! After a minute, everyone was relieved when the phone was turned off.

The shipyard representative was a little confused. "Why is this happening? It can run without cooling, but malfunctions with cooling? But if it doesn't dissipate heat for a long time, the machine will burn out."

The representative of the diesel engine factory still knew very well. After all, he was an industry insider. "Without heat dissipation, everyone will expand in the same way. Of course there is no problem. Once heat is dissipated, the design is insufficient to match the size."

This experiment once again verified that there were problems with the coordination of temperature, expansion coefficient, and matching dimensions, and the designer was also blushing.

"I'm sorry. It's true that we didn't think carefully and ignored this problem. We will recalculate it when we get back and try to make it right as soon as possible."

The designer focused on the strength and toughness of ductile iron, and indeed made significant modifications to the original engine, but ignored this inconspicuous factor.

"Our factory has several sets of product matching dimensions that can be provided for your reference. Of course, individual engines vary greatly, so this is just a reference."

The designer understands this principle and cannot copy it, but thanks anyway.

Logically speaking, there would be nothing left to do with the steel rolling mill, but the factory, the military, and the designer all proposed that the comrades in the steel rolling mill should stay for a few more days to wait for the new drawings and samples to be produced, and then leave after a smooth test run.

There was no choice but to stay. This was a key task and success had to be ensured. Zhu Xuefeng was specially invited to participate in the redesign of the engine.

On the contrary, I learned a lot. This kind of giant engine was something Zhu Xuefeng had never thought about or been exposed to. Many of his ideas and ideas had strong guiding significance. .

In the remaining days, Zhu Xuefeng and others briefly visited the shipyard under the leadership of the military and the factory.

In fact, it is just a look outside, but you are not allowed inside the factory.

"This is the ship this time. How about it? It's big."

A large, completed ship is parked in a large factory building in a hidden bay.

"It's indeed quite big. It should be a frigate."

"Well, this is the latest frigate that was just developed. It weighs 115 tons. If we have our own engine, it should be able to reach a speed of 35 knots. By then, in terms of speed, no one in this area can outrun us. Even if the bald eagle comes, it can't escape us."

Indeed, the speed of 35 knots is amazing. At this time, no ship can run so fast. The key is that this frigate is small, only 115 tons, but it is still enough for offshore patrol and defense. There is nothing too powerful in this area. Navy ship.

"Originally we wanted to import an engine. Lao Maozi's engine is cheap and powerful, but it can only run for 450 hours and the engine will be scrapped. There is no way."

"Can such a small amount of working time be called an engine?"

Zhu Xuefeng and his party were all surprised. According to this theory, he would be dead after running for less than twenty days. What the hell is this?

Representative Niu smiled awkwardly, "This engine is for torpedo boats, so it is designed to have such a long life." (Historical fact)

Everyone suddenly realized that the torpedo speedboat looked fast and rusty, but its existence was tragic.

At this time, the navy only had a reasonable number of torpedo speedboats. The weapons for offshore warfare were half-suicide speedboats. There was no way, the navy was poor.

The movie I watched in my childhood emerged involuntarily in my mind. A group of torpedo boats circled around a giant destroyer, which was called the wolf pack tactics. They forced the arrogant destroyer to retreat. It was really sad. There was no essential difference between it and the car bombs of later generations.

"Yes, the navy is still too poor. It can only develop some offshore combat capabilities, mainly defensive."

Representative Niu nodded, "So later we wanted to import Minde's engine, which has 1300 horsepower. Unfortunately, the gap was too big. We needed at least units, and the country couldn't afford it, so we gritted our teeth and developed a new engine."

"I have to thank you, the steel rolling mill, for promptly developing new materials, new technologies, and technology to increase engine power. Without you, even if one of them is missing, we wouldn't be able to do it."

If the Navy's engine can succeed this time, it is true that the three key technologies of the steel rolling mill are indispensable.

"After we designed it, we calculated that the maximum power can reach 1600 horsepower, which is better than the imported one. Haha, it doesn't cost much. When it is successful, we will report it to your factory and ask for credit."

...

"Even though our ship is not that big, the naval guns and anti-aircraft artillery on the ship have very strong firepower. In our part of Asia, there is nothing more powerful than this."

Zhu Xuefeng also had the impression that this should be the Type 62 frigate of later generations, but he didn't know if it was the final version. A total of nearly four hundred ships were produced in later generations, and seventy or eighty of them were sold out. The rest were kept for twenty years. It is considered the main ship of the navy.

Although the navy also has a few destroyers of several thousand tons obtained from Lao Maozi, they are too few and too precious after all.

The family was too poor to let these treasures participate in the war. They wanted to train talents for the navy. The ones who really picked up the bricks and rushed forward to fight were the small gunboats with tens or hundreds of tons.

Thinking of the Navy using small gunboats to fight hand-to-hand with the enemy, I feel a little sad in my heart. I still remember the tragic scene of the fearless fishing boat ramming the Fuso frigate, and then returning to the port with its bow gloriously deflated.

The lack of large ships cannot be solved in a short time. The multiple difficulties of national strength and technology can only be left to time.

Looking at the neatly arranged small speedboats not far away, it goes without saying that these are torpedo speedboats. Sure enough, I heard the introduction from Representative Niu.

"This is our torpedo speedboat, which is currently the largest in the world in number. Its speed can reach up to 50 knots. No ship can escape its pursuit."

The rest is not said. Everyone knows that if they catch up, they will most likely be sacrificed. They have no defensive capabilities. The main weapon is torpedoes. The soldiers on the speedboat only have conventional light weapons. Under the firepower of naval guns and ships...

The torpedoes of this period were also very unreliable, and the imitations were very immature. After Da Maozi left, the progress was not smooth, so every torpedo was a treasure and had to be fired closely.

...

The waterproof shield of the torpedo boat being processed still inspired Zhu Xuefeng a lot. He didn't know much about ships and ship structures, but the partition compartment to prevent sinking immediately reminded him of the assault boats that would be used in later generations.

By the way, if there were a batch of assault boats in the summer of the year after next, how many families and lives would have been saved. As a later-generation Beijinger who has experienced the baptism of floods, I know very well.

The overwhelming information made him remember that in the next two years, floods will occur in many places in the mainland, especially in the year after that, that is, in 2003, there will also be major floods caused by rare precipitation in Beijing, Hebei, and Tianjin. Countless people will be displaced and bring great harm to the capital. Causing great confusion.

(End of this chapter)