Yue Yunhe also looked at the two of them again, and said with a smile: "The Ministry of Electric Power also has a purpose in electing these two little comrades, after all, our age is here, whether it is thinking and the technology in the brain, it is more traditional and old, let the little comrades use new thinking and new angles to discuss and discuss, it is beneficial and harmless." ”

In the eyes of most people, power technology has always been hard, stable, not new, besides, most experts have not retired, not out of production, how can they technically lag behind these two young people?

Yue Yunhe didn't say anything more, and started the topic on this.

"After the first nine discussions and research results, based on the 175-meter water storage plan, on the power system and mechanical and electrical equipment, the conclusion of this group is as follows, I here carry out the final reading of each item, point by point, each of which is read out, the final statement and discussion, and the final determination of the demonstration report. ”

The design of the storage level of the Sanxi Dam was the basis for a follow-up study, and after decades of discussion, the design of the 175-meter storage level finally came to the fore.

The seemingly simple figure of 175 meters is actually the result of a comprehensive study of geology, environment, hydrology, power generation technology and so on, which can be explained clearly in a few words. As Zhang Yifu, he only needs to know the simplest truth: the lower the water storage level, the lower the water storage, the smaller the actual effect of the dam, the less impact it has on the environment, and the smaller the power generation.

Vice versa.

In fact, there are many people who oppose 175 meters, which is already a height that has been achieved for a long time, and of course it can be higher, but it is a higher challenge to technology, and the impact on the Yangtze River will be greater, and no one can afford to play.

Why did Yue Lao say that the demonstration of power generation technology should also be based on this 175. The reason is also very simple, according to secondary school physics, P=ρgh, which translates to the pressure inside the liquid, increases with depth, so our water storage level is higher. The deeper the head of the turbine generator, the greater the pressure to push the impeller.

In this way, the principle of hydro-generator set is actually much simpler than that of thermal power generator set, and the boiler turbine and water vapor pipeline are not needed, and the water flow directly pushes the runner to rotate and cut the magnetic inductance line to generate electricity, which saves the thermal part at the same time, but also saves tens of millions of tons of oil and coal.

Of course, this explanation of the relationship between water storage level and power generation is somewhat superficial. A little more scientific, introduce a noun for "water head" to measure this qiē. Water head refers to the mechanical energy of the liquid per unit weight, which is somewhat similar to the meaning of potential energy, it can be said that the higher the water storage level, the higher the water head, the greater the potential energy, the more work done, and thus the greater the power generation. The concept of "maximum head" is used in the engineering design. Because at different times of the year, especially during the dry season and flood season. The difference in water head is relatively large.

Judging from the information held by Zhang Yifu, the experts have already made this part of the calculation.

The water levels are assumed to be 156 m and 175 m respectively.

Then their maximum head is 93 meters and 112 meters, respectively.

The resulting average annual power generation is 70 billion kilowatt hours and 85 billion kilowatt hours.

Roughly speaking, the difference in water storage level of 19 meters represents the difference of 15 billion kilowatt-hours of electricity in a year. It is roughly equivalent to 4 to 5 power plants in northern Hebei, or tens of thousands of Wen Tianming.

However, according to the actual situation known to Zhang Yifu, the maximum annual power generation of Sanxi will reach almost 100 billion kWh in 20 years, which is more Wen Tianming......

Anyway, Zhang Yifu had already wasted so many brains in order to understand the first sentence Yue Yunhe said. What can Xia Xue do?

Looking at Xia Xue, he was not in a hurry, and he didn't even look at the report in his hand.

"Are you sure you understand?" Zhang Yifu asked in a low voice, "Do you want me to tell you about it?"

Xia Xue looked at Zhang Yifu disdainfully: "Do you know why I applied for the electrical power major?"

"Huh?"

"Because of the water conservancy books, I was already in tatters when I was in high school. Xia Xue's expression revealed a sense of freehand of a lonely madman.

“……”

The cold that I hadn't felt for a long time blew gently again, and if I spent my spare time reading...... Don't be too scary.

After Yue Yunhe briefly glanced at the crowd, he immediately began to read out item by item.

"Let's start with the hydro-generator set. The first point is the selection of turbine type, according to the 61-112 meters head change range, you can choose Francis or oblique flow turbine, considering that the Francis structure is simple, the technology is mature, widely used at home and abroad, with rich experience in design, manufacturing and operation, the foreign production of more than 500,000 kilowatts of turbines are Francis type, oblique flow type is ............ Therefore, the Sanxi power station should use a Francis turbine. ”

Yue Yunhe raised his head and said: "Today, the final report must be determined, if you have any opinions, you can put it forward immediately, including the two junior comrades, after the discussion, the plan will be put forward and signed, and there will be no point in arguing at that time." ”

Zou Shiliang said with a smile: "Mixed-flow is definitely the only choice, and there is no dispute. ”

"Yes, that was confirmed at the third meeting. ”

"The diagonal flow type is only used in small units, how can it be used in Sanxi. ”

In the midst of laughter, Zhang Yifu also asked Xia Xue in a low voice: "What's the difference between these two?"

"What kind of big-tailed wolf are you pretending?"

"No, I don't know. ”

"It's to make the structure very complicated and improve efficiency, and the large unit doesn't dare to use it, and then explain it in detail, I have to draw a picture for you, and then I will talk about it later." ”

"I see...... "Zhang Yifu is really convinced, this kind of unpopular professional knowledge is so clear.

After confirming that there was no objection to this, Yue Yunhe continued the process of the meeting.

"The second small point of the hydro turbine part, about the capacity of the unit, there are some small differences, most of us think that 700,000 kilowatts is more appropriate, a small number of people think 800,000 or 600,000, and a very small number of comrades insist that 500,000 is better, which is one of the two core issues discussed at this meeting, and I hope to determine a conclusion. ”

Yue Yunhe said, looking at Lao Zou next to him: "Shiliang, you can speak on behalf of 700,000 first." ”

"Hmm. Zou Shiliang took the information in his hand and said to the surroundings, "According to the spirit of the central government and the water resources of our Sanxi, this power station must be the world's first hydropower station, and the unit capacity must also meet this standard." Judging from foreign experience, 50-700,000 units are the mainstream of large power stations, some of which have been put into operation for 10 years, taking the world's largest Itaipu hydropower station as an example, 700,000 units have been put into operation in the past ten years, which is the golden rated power of advanced hydropower units, the best combination of technology, efficiency and economy, and we have no reason to oppose him. ”

"Really?" Zhang Yifu asked Xia Xue in a low voice.

"Definitely, Sanxi's unit is at least 700,000. Xia Xue nodded, "No matter how high the stand-alone machine is, it is useless, on the one hand, the water head will be wasted, on the other hand, the technical difficulty and cost have increased sharply, it is better to directly put on two 700,000 units." ”

"You know that. ”

"These materials are on my dad's desk every day......"

Soon after Lao Zou's voice fell, another younger expert spoke: "Leaders and experts, I did support 800,000 before this, and the reason is very simple, after all, it is Sanxi, and the goal is the world's largest power station, I think we should do more first, and the 800,000 unit is undoubtedly more efficient." Specifically, assuming that the target installed capacity of Sanxi is 20 million kilowatts, 29 units need to be built if 700,000 units are selected, and only 25 units are needed if 800,000 units are selected. All of you here are power experts, but we should pay attention to the fundamental difference between hydropower and thermal power, adding a unit of thermal power is nothing more than the expansion of the power plant in the area of the power plant, and hydropower needs to open a new water inlet on the dam, which has a considerable impact on the entire dam, the number and density of our water intakes will affect the stability of the dam, it must be as little as possible, so I support the 800,000 units in order to consider the expansion of Sanxi in the future. ”

"Before expanding the capacity, the first thing to consider is stability. One person on the other side quickly retorted, "Sanxi is the first time to engage in a project like Sanxi, we must be down-to-earth, and we must not be ambitious, we can first ensure the stable operation of 700,000 yuan, and then consider the 800,000 you mentioned." ”

"Yes, you're right. The young expert immediately nodded and said, "Later, I also did some research privately, 800,000 units are indeed rare in the world, if you start to use it, there are still certain potential risks, we must first achieve stability before we can consider these problems, so I no longer insist on 800,000, agree to the 700,000 single machine capacity plan." ”

The people around nodded one after another, and finally got one, and 700,000 seems to be a certainty.

At this moment, an old lady's voice came......

"You always have one international and one foreign mouth, have you ever considered the importance of the Three Creeks Project?"

Zhang Yifu also noticed that there was such a female old expert in the venue!

The old lady with white hair neatly turned her head, and at the same time with a pair of very thick black plastic eyes, wearing a dark blue top, how do you look...... It's all a rather old-fashioned and terrible existence.

No one spoke, and everyone's expressions were rather embarrassed.

The old lady looked around and continued: "I know that many people think that the unit of 500,000 is too small and too backward, but to be honest, this is the unit that we have the ability to make domestic units. The Yangtze River is the lifeblood of the country, and Sanxi is the throat, so how can it be possible for the US imperialists and Germany to set foot here? I believe that the Sanxi project must adhere to absolute domestic production, and 500,000 domestically produced units is the only choice; of course, with technological progress, we can completely develop 600,000 or 700,000 units, and then we can go up again. ”

After the breathtaking old lady's voice fell, no one was in a hurry to refute, they were all embarrassed expressions, some coughed twice, and some scratched their heads.

Seeing that no one spoke, the old woman looked sideways at Lao Zou: "Shiliang, you can talk a few words, don't you take a clear-cut stand and insist on resisting US imperialism in terms of automation? You know best the importance of national security." (To be continued......)