Ovo je vrlo neupadljiva stvar. Veličine je samo dlana i malo je težak za ruku. Njegov oblik je prilično poseban. Tanka metalna cijev je poput stupa, nosi dva debela metalna cilindra, a jedan od metalnih cilindara prati polovina cijevi nešto tanje od malog prsta.
Jedan od vazdušnih{0}}hladnjaka pulsnih cijevi
Zhao Miguang, istraživač na Institutu za fiziku i hemiju Kineske akademije nauka (u daljem tekstu Institut za fiziku i hemiju Kineske akademije nauka), rekao je da bi izrada ove stvari koštala oko milion juana. sad. Međutim, prije 2000. godine strane zemlje ga ne bi prodavale Kini, ma koliko koštao.
It is the "cooling artifact" that has plagued China's optical remote sensing satellites for decades - the aerospace-grade pulse tube refrigerator, a high-tech product that can quickly reduce the local temperature to minus 200 degrees Celsius and will not be damaged for many years.
Its birth and development in China benefited from a "long run" by researchers from the Chinese Academy of Sciences.
Ohladite na minus 200 stepeni Celzijusa za nekoliko minuta
Dana 25. januara, satelit ZY-1 02E opremljen sa tri pulsna cijevna frižidera domaće proizvodnje-uspješno je dobio slike visokog{7}}kvaliteta. Ova tri pulsna cijevna hladnjaka su 26., 27. i 28. pulsni cijevni hladnjaci za vazduhoplovstvo koje je razvio Institut za fiziku i hemiju Kineske akademije nauka i koji se uspješno koriste u svemirskim projektima.
The new crown epidemic has made many people aware of "infrared temperature measurement" technology. When the human body passes through the thermal imaging camera, the hot spots on the body will appear red. In order to measure the temperature of the earth and the atmosphere, many meteorological satellites are also equipped with infrared detectors. However, due to the distance from the target detection object, the infrared detector on the satellite needs to maintain a low temperature or even an extremely low temperature level in order to detect the slightest heat change on the distant target.
Dakle, kako zadržati infracrveni detektor na satelitu u stanju niske temperature? Naučnici su izmislili dvije vrste rashladnih tehnologija, jedna je pasivno hlađenje zračenjem, koje se zasniva na principu da objekti visoke{0}}temperature mogu zračiti energiju prema nisko{1}}objektima; drugi je aktivno mehaničko hlađenje, princip je stvaranje plina mehaničkim kretanjem. ekspanzije, a fenomen hlađenja nastaje kada se gas širi.
"The cooling temperature of radiation cooling is high and the cooling capacity is small. Although it can be used to cool small detectors, it cannot meet the higher requirements for low temperature of aerospace devices. In contrast, mechanical cooling technology is more feasible." Chinese Academy of Sciences Physics and Chemistry Chen Houlei, a researcher at the institute, told the China Science Journal.
Tehnologija hlađenja s pulsnom cijevi je vrsta mehaničke tehnologije hlađenja. Godine 1963. američki naučnici su slučajno otkrili da kada postoji naizmjenični val pritiska u šupljoj cijevi, njen zatvoreni kraj će se zagrijati i može se formirati veliki temperaturni gradijent duž aksijalnog smjera cijevi. Na osnovu toga su razvili pulsno cevno hlađenje. mašina. Godine 1984. sovjetski naučnici transformisali su frižider sa pulsnim cevima, što je uveliko poboljšalo njegovu efikasnost hlađenja, a takođe se povećala i toplota vezana za istraživanje.
Pointing to the pulse tube refrigerator in his hand, Chen Houlei introduced: "This part similar to the little finger is called the 'cold finger'. This small refrigerator can reduce the fingertip to minus 200 in a few minutes. Celsius. We put the probe on the fingertip, and when the temperature of the probe cools down, we can see the earth clearly."
Od teorije do inženjerstva
In the 1980s, the Cryogenic Technology Experiment Center of the Chinese Academy of Sciences (one of the units of the Institute of Physics and Chemistry of the Chinese Academy of Sciences) took the lead in starting the basic research on pulse tube refrigeration technology in China. By the 1990s, they had set the record for the lowest refrigeration temperature several times, achieved a series of original achievements, and won the "Kapicha Award" and "Linde Award" of the International Society of Refrigeration.
In 1998, the United States was the first to engineer pulse-tube refrigerators for use in space programs. Although my country has achieved world-leading results in the basic research of pulse tube refrigeration, optical remote sensing satellites have been suffering from lack of their own space refrigerators. "At that time, the research and development unit could only import from abroad, and the aerospace-grade refrigerator was embargoed to our country. The research and development unit could only try every way to buy the ground-level refrigerator." Zhao Miguang said.
The reason for saying "bitter" is that the lifespan of imported ground-level refrigerators is less than 1/10 of that of aerospace-grade refrigerators, and problems often occur, and after satellites are launched, they cannot be repaired at any time like they are on the ground. Once on-orbit failure, the country may pay a huge price.
Krajem 1990-ih, uz podršku Nacionalnog naučnog fonda za istaknute mlade naučnike, Kineske akademije nauka i drugih relevantnih odjela, istraživački tim Instituta za fiziku i hemiju Kineske akademije nauka počeo je da se transformiše u primijenjena istraživanja. kao cjelina. Suočavajući se sa velikim potrebama u oblasti nacionalnog svemirskog daljinskog otkrivanja i infracrvene detekcije, izašli su iz gomile starih papira i sproveli istraživanja o inženjeringu hladnjaka sa pulsnim cijevima i svemirskim aplikacijama. Počevši od 2000. godine, tim je dobijao sistematsku podršku Nacionalne svemirske agencije.
The road from theory to engineering is full of challenges. "What we want to do is aerospace-grade products. If the refrigerator will work in the sky in the future, it must be guaranteed that it will not break for 8 years, 10 years or even longer." Chen Houlei said.
Frižideri su punjeni gasom helijuma i moraju osigurati vrlo nisku stopu curenja molekula helijuma kroz pouzdanu tehnologiju zavarivanja i brtvljenja. Kompresija i ekspanzija plina ovisi o klipu. Moraju učiniti da klip i zid cilindra budu i zatvoreni i beskontaktni, kako bi se osiguralo da se klip ne istroši kada se ulje ne može koristiti. Kretanje klipa je podržano ravnom oprugom, a oni moraju pronaći načine da osiguraju da opruga ne bude kriva, a kamoli slomljena.
Every "must" means a pressure. "At that time, we encountered some problems, and we couldn't move forward for a long time, and everyone's morale was very low." Zhao Miguang said.
Summarize the progress at 8:00 in the morning, and leave work at 12:00 in the evening. In this way, 8 years have passed. In the past 8 years, Riyuexingchen has witnessed their road to tackling key problems: the pulse tube refrigerator they developed achieved full welding of titanium alloys; the distance between the piston and the cylinder reached the micron level; the leaf spring can move 100 in the anti-fatigue test. More than 100 million times, there is even a spring's anti-fatigue test "running" for more than 10 years, and there is no problem so far.
Pušteno je u rad 28 pulsnih cijevnih frižidera
In 2008, under the leadership of researcher Liang Jingtao, the current director of the Key Laboratory of Space Work-Heat Conversion Technology, Institute of Physics and Chemistry, Chinese Academy of Sciences, the scientific research team developed my country's first long-life pulse tube refrigerator in space, and successfully carried out on-orbit verification. The refrigerator has achieved a historic leap from scratch, from tracking to entering the latest international development stage, and my country has thus become the second country after the United States to master the space pulse tube refrigeration technology.
Since then, the "stumbling block" in the development of optical satellites in the infrared spectrum has been kicked away, and the planning and demonstration of a series of satellite models in the country has been in full swing.
Technological innovation creates demand, which in turn drives technological development. In the following ten years, the development of my country's spaceborne infrared detectors has continuously put forward higher requirements for spaceborne pulse tube refrigerators.
Satelit Gaofen-5 uspješno je lansiran 9. maja 2018. Opremljen je pulsnim cevnim frižiderom velikog kapaciteta hlađenja i dugog veka trajanja koji je razvio Institut za fiziku i hemiju Kineske akademije nauka.
This satellite carries my country's first full-spectrum spectral imager covering the visible, near-infrared, short-wave, medium-wave, and long-wave infrared spectrum bands. Compared with previous optical detectors, it is larger and heavier. In order to adapt to the demand, the chiller project team boldly adopted a new solution. The chiller could only carry the cold finger of the cold platform with a size of more than ten millimeters and a weight of a few grams, and designed it into a detector assembly with a size of one hundred millimeters and a weight of one kilogram. .
U prvih nekoliko godina, put ka pretvaranju dizajna u stvarnost bio je neravan. Međutim, što više neuspjeha doživite, radost uspjeha postaje nezaboravnija.
"This is a new international initiative!" Chen Houlei's eyes lit up when he said this.
At 11:11 on December 26, 2021, the "Ziyuan No. 1 02E" satellite was successfully launched at the Taiyuan Satellite Launch Center. The long-wave infrared detector carried on it must work in a low temperature environment of minus 193 degrees Celsius. The spectral imager on Gaofen-5 is larger and requires twice the cooling area of the pulse-tube refrigerator.
During the development process, researchers encountered unprecedented difficulties. "The design life of the 'Zuanyu No. 1 02E' satellite is 10 years, which is higher than the previous 8-year life requirement. In order to meet the project requirements, we proposed a plan to use the switching device to backup the compressor. In the case of increasing the limited weight, the large It greatly improves the life of the refrigerator." Liu Yanjie, the chief designer of this pulse tube refrigerator and an associate researcher at the Institute of Physics and Chemistry of the Chinese Academy of Sciences, told the China Science Journal.
"During the design of the cold finger, the large-area cold plate we used had a deformation problem due to thermal expansion and contraction, and the detector on it was easily broken." The cold finger designer of this pulse tube refrigerator, Quan Jia, an associate researcher at the Institute of Physics and Chemistry of the Chinese Academy of Sciences, recalled that after countless discussions and debugging, they made a new material match for the cold plate and finally solved the problem.
Danas su razvili vazduhoplovne{0}}pulsne cijevne frižidere različitih oblika i performansi, od kojih je 28 lansirano u orbitu.
Svaki projekat je pun izazova, a ti izazovi su pokretačka snaga tima za razvoj hladnjaka s pulsnim cijevima.
"We are developing more advanced space low-temperature refrigeration technology with a cooling capacity of more than 100 watts, a temperature close to absolute zero, and a weight as low as a few hundred grams." Liang Jingtao said that the team will build on the successful development of the space pulse tube refrigerator. Continue to carry forward the spirit of "daring to challenge and fight hard", bravely assume "national responsibility", and forge ahead to meet the needs of low-temperature refrigeration in future spaces.
On the development road of aerospace-grade cryogenic refrigerator technology, this "long run" continues.