Chapter 459 This is good stuff!

Gao Zhendong drank water while looking at the system store.

This has become his habit for some time. He always goes to see if the thing is still there every day.

Fortunately, it has always been there. It seems that the sentiment is not for sale. Maybe the rich girl in the school broke up with her boyfriend, so this thing fell into the hands of the boss? Gao Zhendong thought in a rather unreliable way.

Just as he was about to close the store, something suddenly flashed in the corner of his eye, and it seemed different from before.

It should be from an outdoor store. This store has good stuff. At least the thermal imager was made there.

Gao Zhendong remembered seeing this thing before, but this time it seemed to have a few more words.

——Outdoor refrigerator (with refrigeration).

Gao Zhendong had seen this thing before. It was a pure fraud. It was just an insulated bag made of insulating material. You could put some ice cubes or ice cream in it to keep it from melting for a while, but it was far from a real refrigerator.

But this time, the three new words at the end aroused Gao Zhendong's interest.

Is it because the original scam product is not selling well, and the owner of the outdoor store is finally willing to update the product?

If Gao Zhendong remembered correctly, there were two types of outdoor or car refrigerators with refrigeration that he had seen in his previous life.

There is a semiconductor refrigeration unit with a fan for heat dissipation, and the effect is pretty average.

The other type uses a small compressor. This thing is the same as the refrigerator that we often talk about, except that it is smaller in size and power, but the cooling effect is better than that of semiconductor refrigerators.

When Gao Zhendong thought of this, his interest in this outdoor refrigerator suddenly increased. What a good thing! It might be useful!

Without hesitation, he took the thing out of the store.

Hmm, interesting. It's basically the same as it looks now. It seems that there is no need for too many changes to suit the era.

I couldn't wait to open the instruction manual in my mind.

——Semiconductor refrigeration!
This result made Gao Zhendong very happy and he laughed out loud.

What we want is the semiconductor refrigeration chip!
Semiconductor refrigeration uses semiconductor P and N thermocouples. When voltage is applied to both ends, a temperature difference is formed between the upper and lower surfaces, thereby achieving cooling.

Yes, there are thermocouples here, but they are just the opposite of thermocouples for measuring temperature. Thermocouples measure temperature by generating thermoelectric potential based on the temperature difference between the hot end and the cold end. Semiconductor cooling chips, on the other hand, use electromotive force to obtain temperature difference.

In fact, although this thing did appear around 1960, its core principles and phenomena were noticed as early as the 19th century, namely the Seebeck effect in 1821, the Peltier effect in 1834, and the Thomson effect in 1855.

Although these effects were observed at the beginning, the principles were not understood, so the results were extremely poor and had no practical significance.

There were no semiconductors at that time, so antimony-bismuth (Sb-Bi) thermocouples were used. As for the effect, it could only prove that this thing was useful in principle, but in fact it was useless, and the cooling efficiency was less than 1%.

It was not until the development of semiconductors in the 20s and 50s that the correct key to open this door was found.

However, people who use portable refrigerators generally don’t like this thing because the cooling effect is not good. Common semiconductor refrigeration refrigerators can have a temperature difference of about 20 degrees with the ambient temperature, which is considered good.

But Gao Zhendong is different, he wants semiconductors.

He knew one thing, that is, semiconductor refrigeration chips can actually lower the temperature to a very low level. The reason why portable refrigerators are not very effective is due to problems with material specifications, cabinet design, and heat dissipation design.

That's right, semiconductor refrigerators need to dissipate heat. At its hot end, the heat must be dissipated quickly in order to provide continuous cooling and achieve a good cooling effect.

The line-scan thermal imager that Gao Zhendong obtained was originally a civilian uncooled thermal imager without a cooling system, which greatly reduced its actual effect.

When Gao Zhendong was making a practical line-scan thermal imager, he had to add a cooling system. This brought up a question: how to cool it?

This is different from a missile, which is a one-time deal. It uses a gas cylinder to compress the air, expand it, absorb heat, and cool it down.

Compressor? That thing starts slowly, has a complicated structure, and is not easy to use. It should not be used unless it is absolutely necessary.

There is no other refrigeration technology that can be used in military equipment and is cheap, easy to use, and maintain!

But semiconductor refrigerators are different. They are all solid-state, light, thin, easy to install, easy to arrange, and reliable. Even with a heat dissipation device that works miracles, they are still far better than compressors.

Moreover, the temperature control is precise, the cooling is fast, and the switching between hot and cold is convenient.

Of course, it is not without disadvantages, such as low efficiency and poor economy, but these are not a problem under specific requirements. Low efficiency can be overcome with great effort, because low efficiency and low cooling capacity are two different things. It just means that more power consumption is required to feed it.

In Gao Zhendong's previous life, this thing was the first choice for cooling many military equipment.

Gao Zhendong also wanted to do it, but he had not studied this thing much in his previous life. He just knew about it, but he had not collected any materials. It was not easy to do it with just the things in his head, mainly because he didn't know what materials to use. Now with this, all problems are solved!

Gao Zhendong was not worried that the semiconductors in the refrigerator would not work well. What he wanted were the principles and materials. According to the habits of semiconductor factories in the past, they would definitely use the best types of materials. The only difference was that the specifications were slightly worse, but there would be no problem with the type of materials.

Bad material types have long been eliminated, and even if manufacturers want to maintain production lines of low-performance materials, they usually end up losing money.

For example, with the emergence of mercury cadmium telluride and indium antimonide, lead sulfide has basically disappeared from military infrared applications, and the same is true for civilian use.

Moreover, the structure of the semiconductor refrigerator is very interesting. It is actually a thermopile composed of semiconductor thermocouples, and this composition can be series, parallel, series and parallel... This means that even if the material is inferior, miracles can be achieved with great effort!

This is very comfortable.

So Gao Zhendong couldn't wait to look through the instructions of the refrigerator in his mind, and sure enough, in the refrigeration part, the materials of the refrigeration plate were explained clearly.

以碲化铋为基体的三元固溶体合金，其P型半导体是Bi2Te3—Sb2Te3，N型半导体是Bi2Te3—Bi2Se3。

It looks a bit complicated, but it doesn't matter, the instructions are very complete, including the theory, and this thing does not have high requirements for the crystal structure. It requires that the thermocouple should be short and thick, not long and thin, so the cooling plates you see are in the form of sheets rather than rods. As for the processing technology, hehe, there is no such thing as a process.

Even the structure is clearly given. What Gao Zhendong wants to do is the bismuth telluride matrix.

Moreover, for Gao Zhendong, this matter is very similar to DJS-59. In theory, he only needs to prove that he has started to work on the bismuth telluride matrix, and then after a period of time, he can take this matrix to the 1274 factory for doping.

In short, he just needs to prove that he has the research process, and then he can show this thing to everyone.

Thinking that his line-scan thermal imager had become even more powerful, Gao Zhendong couldn't help humming a song.

Lou Xiao'e lay on the table with her chin resting on her hands. Looking at Gao Zhendong like this, she smiled. She didn't know why Gao Zhendong was happy, but seeing Gao Zhendong like this made her happy.

The couple was having a great time when they suddenly heard a commotion in the middle courtyard, as if a child was being beaten and was screaming loudly.

Beating children in the Central Courtyard? This is rare. The Jia family has the most children.

The couple looked at each other, walked away and watched the fun.

It is not necessary to intervene, as they are educating their children, but it is always okay to keep an eye on it.

With their heads full of gossip, the couple walked to the middle courtyard. People from the neighboring houses came over to watch the fun, and even the people in the back house were alarmed.

The central courtyard is very lively.

Banggeng was running in front, screaming, while Qin Huairu was chasing him with a feather duster, shouting, "I told you not to waste money! Today I will beat you to death, you little bastard!"

Bang Geng ran to Yi Zhonghai and his wife and shouted, "Grandpa, grandma, save me! Save me!"

The couple probably knew why he was beaten, and they said with a smile: "This won't save you, just let your mother beat you a few times to calm down your anger."

Seeing that there was no hope here, Bang Geng turned around and threw himself into Sha Zhu's arms again: "Uncle He! Uncle He! Save me, I know you are the best!"

Sha Zhu seemed quite interested, and just as he was about to speak with a shy face, he said, "Sister Qin..."

Qin Huairu raised her feather duster and pointed at him: "Silly Zhu! Don't say anything! If you help him, I will beat you up too! Do you believe it?"

Sha Zhu was frightened at once, grinning foolishly, then pushed Bang Geng out. Bang Geng was hit on the butt a few more times before he rushed out of the damn encirclement. Desperate, he ran to Gao Zhendong for help.

"Uncle Gao, Uncle Gao, save me! Save me!"

It's not to mention that he found the right person. Qin Huairu couldn't do anything with Gao Zhendong, for fear of accidentally hitting Gao Zhendong. She knew that with Gao Zhendong's personality, he wouldn't care, but she would feel bad if that happened.

Gao Zhendong asked with a smile what happened, and Qin Huairu angrily told him what happened.

It was not a big deal, Xiaodang was just greedy, so Banggeng took two tubes of toothpaste tubes from home and exchanged them for a piece of Cuban candy from a junk collector, which he dissolved in water and shared with Xiaodang.

Moreover, the elder brother was quite well behaved and even fed the tiny Jia Zhenzhen a few bites.

The only problem is that these two tubes of toothpaste were still filled with toothpaste in the morning, one new and one half full.

The Jia family has a large population, so they keep a separate tube of toothpaste for use.

This kid squeezed out all the toothpaste and threw it away, then exchanged it for candy.

(End of this chapter)