"Since Zhou Lao let everyone speak freely, then it's up to me to throw bricks and lead the way. ”

"Our research team is mainly working on the freezing method. Because the start is decades later than abroad, it is more than foreign countries to freeze fresh water, and our domestic in this regard, has just started. Therefore, the results are relatively unproductive. …… There are two main problems, the first is that it consumes more energy, and the second problem is that the freshwater produced tastes poor, and it is difficult to use it for domestic water......"

The people around listened to Professor Wu's report and nodded from time to time, and Liu Feng also nodded.

The freezing method of producing fresh water, he also understood, is indeed a thankless task.

As Professor Wu Qingquan said, there are always two problems that cannot be overcome in this method of producing fresh water.

The so-called freezing, that is, freezing seawater to freeze it, so it inevitably consumes a lot of energy, which is one thing, and at the same time, when liquid seawater becomes solid ice, the salt is separated, but the separation effect is not good, so the taste of freshwater is much better than that of seawater, but it is still unsatisfactory.

Professor Wu Qingquan's research team is more like someone has chased ducks to the shelves. It's just that not everyone is for fame and fortune, especially scientists, who don't care too much about fame and fortune.

Even though he knew that the prospects of this method were not good, Professor Wu Qingquan still took the initiative to take it when he was assigned to this task.

Therefore, in Liu Feng's view, Professor Wu's brick-throwing is more like making a work report.

For Professor Wu Qingquan's team, Liu Feng deeply admired and sympathized with at the same time.

Obviously, the freezing method is the kind of thankless method, whether it is the cost of research or application prospects, it is completely inferior to other methods, and the reason why it is necessary to study must also be considered from the perspective of technical reserves.

Both on the rostrum and off the stage are well aware of this.

In fact, there are many research teams like Professor Wu Qingquan.

Although there are some fields that have not produced in a short period of time, or even have no prospects at all, someone must continue to do them, such as theoretical physics.

Although the importance of frozen seawater desalination engineering is not as important as that of theoretical physics, it is also indispensable to invest in Huaguo, where seawater desalination has just begun to be studied for a few years.

Moreover, the situation is basically the same as that of the freezing method, the distillation method of Professor Liu Yingcai's team from Beijing University, and the dew point evaporation method of Professor Lu Fangping's team from Tongji are all such roles to accompany the prince to study.

After several big names made some expositions on behalf of their respective research directions, it was finally the turn of Lian Xuewen's reverse osmosis method and Wang Shichang's multi-stage flash evaporation speech.

"Ahem, then I'll say a few words too!"

There is a famous saying that the person who knows you best is not yourself, nor your partner, but your enemy.

As Lian Xuewen's main competitor, Wang Shichang saw that Lian Xuewen did not speak in front of him this time, but looked speechless, and when he saw Liu Feng, who was 'at ease with the old god' on the side, he didn't understand anything.

Now, in the field of reverse osmosis, there is a-stirring stick that completely disrupts people's pace!

"Our research team is mainly working on multi-stage flash technology. Although the reverse osmosis membrane technology has developed more and more rapidly in recent years, in terms of application, the world's seawater desalination plant still has the largest output by multi-stage flash evaporation method, and the technology is also the most mature, the operation safety is high and elastic, and it is mainly jointly built with thermal power stations, which is suitable for large-scale and super-large desalination devices.

In our country, thermal power generation still accounts for more than half of the country's total power generation, so compared with other methods, multi-stage flash technology is definitely the most potential in China. ”

Regarding Professor Wang Shichang's speech, Liu Feng also pricked up his ears seriously and was very interested.

After all, in addition to reverse osmosis, the only thing that is interesting about seawater desalination is the multi-stage flash technology.

The so-called flash evaporation refers to the phenomenon that part of the seawater at a certain temperature suddenly evaporates under the condition of a sudden decrease in pressure. Multi-stage flash seawater desalination is to evaporate heated seawater in multiple flash chambers with gradually decreasing pressure, and condense steam to obtain fresh water.

Unlike distillation, which requires the seawater to be heated to boiling, multi-stage flash evaporation can use the waste heat of other plants to heat the seawater, without the need to boil the seawater, so it saves a large part of the energy and the cost is relatively much lower than that of the distillation method.

Therefore, it is obvious that except for Liu Feng, other people are also interested in multi-stage flash evaporation technology, especially Zhang Shu Ji on the rostrum, while listening carefully with pointed ears, lest he miss a word, while looking serious and taking notes in his hands.

At this time, Zhou Lao also nodded seriously.

"What Professor Wang said is indeed true, then, in terms of the most advanced level in our country or abroad, how much can the cost of multi-stage flash evaporation technology per ton of fresh water reach now, and what is its main development trend, can Professor Wang elaborate?"

"The main development trend of multi-stage flash evaporation technology in recent years is to improve the water production capacity of the single machine of the device, reduce the unit power consumption, improve the heat transfer efficiency, etc.; compared with other methods, the multi-stage flash technology is mature and reliable, in addition to the labor cost, the price of multi-stage flash evaporation technology per ton of fresh water is basically stable between 3~4 pieces. ”

"So, my suggestion is that, in the future, we can focus the research and development of desalination on multi-stage flash technology, after all, the potential of this area has not been exploited like polyamide composite reverse osmosis membranes. ”

Professor Wang Shichang finished his speech, smiled and nodded to his peers, and sat down. Obviously, he was very satisfied with the reaction of his peers, especially the reaction of Zhou Lao and Zhang Shuji above.

In response to Professor Wang's speech, the reactions of colleagues from all walks of life were naturally different.

Experts and professors engaged in multi-stage flash evaporation related technologies have expressed their approval, while other peers, especially those engaged in the research of reverse osmosis, have even changed their faces one by one.

Therefore, before Professor Wang's stool was hot, a voice came from the professor's seat at Zhejiang University.

"I disagree with Professor Wang's statement. ”

Finally, Lian Xuewen still stood up.

As a leading figure in the field of reverse osmosis research, if he does not speak, his prestige in this field will be dealt a big blow.

"It turned out to be Professor Lian, you continued. ”

This Zhang SHU has always been very low in front of scholars, and many scholars have a good impression of him.

Straightening the microphone, Lian Xuewen pondered for a moment and spoke.