In the 90s, you could acquire max-level skills every 14 days.

Chapter 119 The coal mine is closed, what will these people eat?

There were no classes on the second day of school.

Zhang Yong arrived at the basement of the engineering building a little after seven o'clock.

When the iron gate was pushed open, Qian Zhiyuan was already standing by the lathe, with the three graduate students from yesterday standing next to him. The four of them were whispering to each other around the blueprints on the control panel.

"Zhang Yong, you're here!" Qian Zhiyuan looked up and greeted him even more enthusiastically than when he saw his mentor.

"Here you are." Zhang Yong changed into his gray-blue overalls and put his backpack in the corner. "What are you looking at? How many spare tapered parts did you make yesterday?"

'

Qian Zhiyuan's face turned slightly red. "Looking at your drawing from yesterday, I made three, and two of them were ruined. Are you free now? Could you make me another one?"

"What's inconvenient about this? Let's do it together." Zhang Yong walked up to the lathe and gently touched the chuck.

The system panel silently appeared in my mind.

[Auto Repair Lv.5: Mechanical tactile feedback ensures uniform chuck clamping force, and the spindle bearing temperature is normal]

"I want to get the rest of the truck out today." Zhang Yong took a piece of chalk out of his work clothes pocket and drew a line on the edge of the control panel. "Zhiyuan, you operate it, I'll watch from the side."

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Qian Zhiyuan took a deep breath and walked to the lathe.

Loading, calibration, and locking the chuck.

The spindle started, and a humming sound filled the entire laboratory.

Qian Zhiyuan put his right hand on the small knife holder handwheel and began to move the first rough cut on the cart.

"Wait." Zhang Yong's voice wasn't loud, but Qian Zhiyuan's hand immediately stopped.

Zhang Yong extended his index finger and tapped a screw on the knife holder.

"Can you feel it? The tool holder vibrates a little at this angle, by about two millimeters. If you don't compensate for this amount, a groove will appear on the conical surface during finishing."

Qian Zhiyuan was stunned for a moment, then reached out and shook the knife holder. Sure enough, it was a little bit unreliable.

How to replenish it?

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"When retracting the tool after rough turning, turn the handwheel in the same direction to keep the clearance pressed to one side."

Zhang Yong made a hand gesture. "Try it, don't reverse the handwheel throughout the entire fine-tuning process?"

'

Qian Zhiyuan nodded and began to cut again.

This time he was much more steady. He finished the roughing cut, then withdrew the tool and changed the feed rate for the finishing cut.

Zhang Yong stood beside him, his eyes fixed on the point where the blade tip touched the workpiece. The cutting sound changed from a piercing screeching to a soft, rustling sound—a good omen.

Six minutes later, Qian Zhiyuan shut off the spindle and unloaded the parts.

I picked up the vernier calipers and measured it.

Taper ratio: 0.2003.

The deviation is less than three ten-thousandths.

Qian Zhiyuan suddenly looked up at Zhang Yong, his eyes lighting up. "It's done?"

'

"Done." Zhang Yong nodded. "While you're still working, make a few more."

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The girl next to me wearing glasses whispered, "He teaches even more meticulously than Teacher Fang."

The other boy didn't even lift his eyelids, and was diligently scribbling something on a piece of paper. The girl leaned over to take a look, and wow, this guy had copied down everything Zhang Yong had just said into his notebook.

Qian Zhiyuan spun three more tubes in one go, and all of them passed the test.

Zhang Yong wrapped the four nozzle parts, along with the one from his own car yesterday, in oil paper and put them in the toolbox.

"Alright, the work is done. I'll treat you to noodles for lunch."

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"That won't do, Master Zhang!" Qian Zhiyuan grabbed Zhang Yong's arm. "There's no way a master would ask an apprentice to do the same. I'll ask!"

'

11:30 a.m.

The second cafeteria of Beijing University.

It was lunchtime, and the cafeteria was bustling with noise. Long queues stretched out at the food windows, the clatter of aluminum trays echoing through the air, and steam billowed out from the window selling pork chops, obscuring half of the glass.

Fang Qiming and Zhao Huaijin had already taken their seats.

An old wooden table, four bowls of pork chop noodles, plus two dishes of pickled vegetables.

Zhang Yong and Qian Zhiyuan sat down with their noodles, while Fang Qiming eagerly picked up his chopsticks and started gesturing with them on the table.

"I just checked your five nozzles, and the precision is fine." Fang Qiming drew a line on the table with his chopsticks. "Next week, I'll take Qian Zhiyuan and the others to the Tongxian Coal Mine for on-site installation. See if you can find the time to invite Qingda, who drew the blueprints last time, to come too?"

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"Okay, I'll go back and ask."

"Before the installation, there's something we need to take care of first."

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He drew another vertical line.

"There's a bend in the main steam pipe on your drawing, and the inner wall has been eroded and thinned. After the nozzles are installed, the secondary air will enter, and the furnace temperature and pressure will change. Will this section of pipe be able to withstand the changes?"

Zhang Yong picked up a large pork chop, chewed it twice, and swallowed it.

"The data Meng Qingshan gave me last time included a record of the wall thickness of this section of pipe. It was manufactured at 12 mm, but the actual measurement shows it's only 8.3 mm. Based on the design pressure of 1.2 MPa, the safety factor is already below 2."

"Then we need to reinforce it." Fang Qiming paused with his chopsticks. "Should we weld on a lining plate or add a clamp?"

"A sling." Zhang Yong said it simply.

"Welding introduces a heat-affected zone. The pipe wall is already thin, and adding another weld will cause stress concentration. It's better to use three U-shaped clamps. 16 manganese steel is sufficient for this purpose."

Fang Qiming nodded, went through the plan in his mind, and looked at Qian Zhiyuan.

"Okay, Zhiyuan, you're familiar with this. Go contact the steel market and get everything ready by next Monday. Remember to get an invoice."

Zhao Huaijin listened for a long time, then tapped the rim of the bowl with his finger.

"Can you three let me finish my noodles before talking about the boiler? The pork chop noodles in the cafeteria won't taste good if they get cold."

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Fang Qiming chuckled and buried his head in his noodles.

Zhang Yong also lowered his head and ate a few bites.

Halfway through the meal, he put down his chopsticks and looked at Fang Qiming.

"Professor Fang, now that the coal plant project is finished, I've been thinking about something much further ahead."

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Fang Qiming looked up. "What's the problem?"

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"The act of burning coal itself."

Fang Qiming didn't stop eating; he took another big bite. "You tell me."

Zhang Yong dipped his finger into the water droplet on the table and drew a circle on it.

"We are now helping Dongsheng Coal Plant upgrade its boilers, which can increase the thermal efficiency from 60% to 75%, saving 800 tons of coal and more than 40,000 yuan a year. This is a good thing."

"But what about looking further ahead?"

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He pointed out a few points in the circle.

"Beijing now burns coal for heating, and the whole city smells of coal smoke in winter. The small coal mines and boiler rooms in Tongzhou and Daxing don't even meet basic emission standards. Coal ash is piled up everywhere, the farmland is covered in ash, and you can't even see the sky."

"Can this situation continue ten years from now?"

Fang Qiming put down his chopsticks and adjusted his glasses.

"What are you trying to say?"

"Natural gas." Zhang Yong held up one finger. "Wind power, hydropower." He then held up two more fingers.

"I guess clean energy will be able to replace coal within twenty years, what do you think, teacher?"

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Fang Qiming shook his head.

"Zhang Yong, I understand your judgment, and I've taught students this before. But I don't agree with it in essence. The main reason is that our country is so big. Building a pipeline to transport gas from Sichuan to the whole country would take who knows how many years."

"The rural people have been burning wheat stalks, corn stalks, and firewood for thousands of years, and it really doesn't cost much money."

"You want him to switch to natural gas? Is he willing to spend the money? Can the pipeline be laid to his doorstep?"

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"If ordinary people are frugal, this project is doomed."

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He stirred the noodles again with his chopsticks and added a sentence.

"It can only be popularized in large cities at most. In small and medium-sized cities and rural areas, it will take at least 30 or 40 years to promote it."

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Zhao Huaijin also chimed in.

"There's another social issue you haven't considered." His tone carried the critical edge typical of intellectuals.

How many coal miners are there in the country? Several million.

"The coal mines are closed, what will happen to these people's livelihoods?! What will happen to the towns that depend on the coal mines for their livelihoods?!"

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