Chapter 471

Li Fang is not the only one. Song Changzheng also stares at Qian Qiang, but he is older and more experienced than Li Fang. He is not as surprised as Li Fang. Instead, he asks, "is it the theoretical value or the actual value?"

"What is theoretical value and actual value?" Qian Qiang looked at Song Changzheng puzzledly: "the gas turbine power of our take-off aviation power is made according to the actual use situation and through real tests again and again. Compared with the overhaul interval of 3000 hours and the service life of 7000-10000 hours of aviation power manufacturers such as general motors, Pratt Whitney and Honeywell, our D series is not as good as others We admit that we can do well, and we are actively looking for solutions. "

He said with a sigh: "at present, the materials of our take-off aero-engine have basically met the requirements of small gas turbine power plant, but there is still a big gap in processing technology, especially in the application of a series of new materials. We haven't mastered it well, especially in finishing and welding. The traditional aero-engine technology is not suitable for this kind of new materials.

Take the welding process for example. In developed countries such as the United States and the United Kingdom, the electron beam welding process is used for the key parts of aero-engine, which not only has good flatness, but also is not easy to deform under high temperature and pressure. At present, many parts of Honeywell engine used in yun-6 transport aircraft use this process, but we know that there are welds in some places, But I can't find where the weld is after disassembling. That's the gap, and there's finishing... "

When it comes to his major, Qian Qiang once again opened his voice. Balabala said a lot about what are the shortcomings of D-series turbine gas power, what are the reasons for these shortcomings, and how to make up for them.

In a word, the 1800 hour overhaul interval and 6800 hour service life of D-series turbine gas power are really poor. If you look at similar products in the United States, how can you be proud and how can you expand? Is it time to celebrate the victory?

Li Fang and song Changzheng were both stunned. They were not stunned, but completely stunned.

1800 hours of overhaul interval, 6800 hours of service life is not high? What is high!

You should know that the overhaul interval of the turboprop-6 on yun-8 is less than 1000 hours, which is still well maintained at ordinary times. The pilot has no rough driving, and it's not impossible to replace the turboprop-6 in 500 or 600 hours for a minor accident.

In fact, it's not just turboprop-6, but the overhaul intervals of other types of engines are generally not high, which is why song Changzheng asked whether it is the theoretical situation or the actual situation.

Because the theoretical values of the engines produced by the domestic power plants are good, but the actual use of the engines in the army is a different picture, but it can not be said that the manufacturers are wrong, because the test data is taken as the average value, and the data will look good when the good and bad are averaged.

It's just like the average fuel consumption of a car announced by the Ministry of industry and information technology. It's reasonable and beautiful. But when you start driving, you're tired and vomit blood, and you can't reach the fuel consumption value announced by others.

The Navy's air force is confronted with the same problem as private car owners decades later. The difference between the theoretical value and the actual value is so great that the army's ground maintenance officers and soldiers feel that if that engine can have a 1000 hour overhaul interval, they will be thankful.

However, with 1800 hours of overhaul interval and nearly 7000 hours of service life, people still say that it is not excellent and there is a big gap. What would it be like to be heard by other aero-engine manufacturers in the country? Can minute old face flushes directly to dig into the ground seam to hide for a while?

"Old money, old money ~ ~"

seeing Li Fang and song Changzheng gradually petrified, Zhuang Jianye quickly stopped Qian Qiang, who was still talking. Qian Qiang was stunned for a moment. He didn't know what Zhuang Jianye meant. Zhuang Jianye also knew that Qian Qiang was not very good at this aspect, so he raised his chin to the filing cabinet beside him: "test the d-50 2000 hours ago Let's give a briefing to some of the heads. "

Qian Qiang narrowed his eyes and suddenly realized that he had said so much. The two naval commanders in front of him didn't believe it and didn't say much. He came to the filing cabinet, took out a d-50 test briefing, turned around and handed it to Li Fang.

Li Fang took it and looked at Qian Qiang, who had no expression on his face: "Qian Gong, isn't the d-50 on the test bench doing a 100 hour phased test run?"

If someone else doesn't understand what Li Fang said, the 100 hour phased test generally refers to the first stage long test of newly assembled turbine power, mainly to check its basic working conditions. So Li Fang's translation is that the d-50 hard track on the test bench is not assembled?

Others don't understand, but Qian Qiang, who is engaged in this field, can't understand it. He shakes his head: "we have done two 2000 hours of long-term test run. Just three days ago, we finished the overhaul and two stages of phased test run, and then we started the next long-term test run. After that, there are freezing test run, rain test run, bird impact test and foreign body inhalation test. After all passed, it is the last one Ten thousand hours of long life test run. "

"We've done two 2000 hour long tests?" Li Fang just felt that the long test briefing in his hand suddenly became very heavy. He almost missed it and fell to the ground.Qian Qiang would like to say, otherwise how do you think the 1860 hour overhaul interval came out? But after all, it is estimated that the other party is the head of the Navy. Instead of saying it clearly, he points to the long test briefing with a smile and signals to himself to see it.

Li Fang quickly opened it, and song Changzheng came to see it together. The more they saw it, the more shocked they were. The roaring d-50 on the test bench completed more than two 2000 hour long tests, or more accurately, three, but the third time did not reach 2000 hours, only 1880 hours.

The reason for this is mainly to determine the overhaul interval of d-50 under general conditions according to the two previous 2000 hour long test runs.

No wonder Qian Qiang said just now that he was so confident in 1860 hours. It turns out that people have already done three tests to change the state.

Now Li Fang and song Changzheng look at the d-50 on the test bench, which is running at a high power of 3000 kilowatts. According to the calculation of the previous hours, the d-50 under test should be about to reach its service life. From the operation, it is no different from the new engine, and even better in some aspects.

What would it look like if such power were installed on the plane?

So Li Fang and song Changzheng looked at each other again, and soon understood the same idea from each other's eyes. Then song Changzheng looked at Zhuang Jianye without hesitation, and solemnly said, "Mr. Zhuang, we will make a special report to the Navy headquarters after we go back, and strive to join the d-50 project. What's your opinion?"