MTL - The Science Fiction World of Xueba-Chapter 496 Engine over temperature
The launch of the 921 rocket was scheduled for the next afternoon, at 5:30 pm on October 30.
The entire launch center was busy as early as a month ago to prepare for this important launch.
Pang Xuelin was only invited to observe the rocket launch guests. Apart from visiting the launch center and encouraging the staff involved in the launch mission, there was nothing else.
At six o'clock the next morning, Pang Xuelin changed into a T-shirt, shorts, and sportswear, preparing to go out for a run.
Although the gene optimizer has greatly improved his body, as long as there is time, Pang Xuelin will still insist on the habit of getting up early and running.
While in Jiangcheng, he took Qi Xin to run together every day, and occasionally Zuo Yiqiu and Zhou Chen also joined in.
Here, only Zuo Yiqiu followed him.
Pang Xuelin opened the door and saw that Zuo Yiqiu, who lived opposite him, also came out wearing tight sportswear.
"Professor Pang, good morning!"
"Good morning! Xiao Zuo, run two laps together?"
"it is good."
The two left the expert building and trot along the asphalt road.
The air in the morning is fresh and humid, the sea breeze is blowing, it is cool and cool, and I feel very comfortable.
Wenchang Satellite Launch Center is close to the coastline, surrounded by lush tropical vegetation, the environment is very good
The two trot along the asphalt road near the rocket assembly plant and came to the launch tower unconsciously.
The huge 921 rocket stood upright, and below the rocket was a large sink deep below the ground. The temperature of the rocket when it was launched was as high as 3,000 degrees Celsius. Therefore, an inverted triangle-shaped aqueduct was installed under the launch pad. Twenty-two meters, surrounding the bottom of the launch tower, will reduce the temperature to a thousand degrees after the rocket is launched to ensure the safety of the ground installation.
The rocket's fuel filling port is still smoldering with white fog.
It is the white mist produced by the condensation of nearby water vapor after the boiling of liquid hydrogen and liquid oxygen.
The first and second stages of the 921 rocket are liquid oxygen kerosene engines, and the third stage uses a oxyhydrogen engine. Since the liquid hydrogen is filled with liquid oxygen, it will continuously evaporate, so the low temperature fuel refill will continue until one hour before launch .
Pang Xuelin and Zuo Yiqiu ran around the launch tower before returning to the expert building.
Nothing happened in the morning, Pang Xuelin stayed in the room until 3 pm, he was accompanied by Tao Yongchang to the command and control center.
Although Pang Xuelin has experienced many science fiction world adventures, he is the first to see rocket launch missions like the real world.
The launch command and control hall was in order and everyone was busy with their own affairs. The arrival of Pang Xuelin did not cause much sensation.
"The booster 1, 3 suspected liquid oxygen leakage failure has been eliminated, and each number follows up and enters the -3 hour program."
"Reset the ignition time to 18:01."
"understand!"
The password sounded from time to time in the hall.
Tao Yongchang was somewhat curious to see Pang Xuelin and explained: "Professor Pang, there should have been some glitches just now, but it doesn't seem to be a big problem and will not affect the normal launch."
Pang Xuelin nodded with a smile.
Aerospace is inherently a high-risk project. It is normal for various minor problems to occur during the preparation of the launch, which generally does not affect the normal launch.
At this time, Liu Xuesong also found that Pang Xuelin came to the accusation hall and greeted him actively: "Professor Pang, welcome to come to guide."
Pang Xuelin said with a smile: "I'm just a layman, I brought my eyes over today, and it was a laugh to guide what it is."
Liu Xuesong smiled and didn't talk much.
Tao Yongchang said: "Old Liu, what happened to the liquid oxygen failure just now?"
Liu Xuesong said: "No. 1 and No. 3 boost the connection of the liquid oxygen filling port there is a problem, which has been solved."
Tao Yongchang said: "That's good, I hope this launch will go well."
The 921 rocket is a new rocket. Generally speaking, this brand-new rocket has a relatively high launch risk.
For example, the failure of the second launch of the Long March V in the past few years directly led to the delay of two key projects such as the China Space Station, Chang'e V, and Mars Rover.
The launch of the 921 rocket this time was the first air-to-air plane verification machine built by China. No matter whether it was Tao Yongchang or Liu Xuesong, the pressure on him was not small.
If it was put in the past, it would be impossible for the top management to directly take the golden and precious payloads such as the space plane verification machine to the new rocket for testing.
Just because Pang Xuelin's Golden Dragon battery harvested global capital, making money was too easy. China was so wealthy that it was directly equipped with an air plane verification machine on the first launch of the 921 rocket.
Liu Xuesong accompanied Pang Xuelin and Tao Yongchang for a few days.
Although he is the chief designer of the 921 Rocket, he does not have to worry about the launch process.
He did the same work on the scene as Pang Xuelin, and he also played the role of a mascot.
Time passed by one minute and one second, unconsciously, it was more than four o'clock in the afternoon.
The commander's instructions sounded from time to time.
"The fuel filling is completed, the filling port is detached."
"Control tower staff evacuated."
"90 minutes to prepare."
"The latest weather forecast shows that everything is normal in the launch window."
"The engine starts to pre-cool."
...
Various instructions sounded from time to time.
At this moment, a sudden alarm sounded at the scene.
"Didi, first-level pre-cooling failure, engine over temperature, first-level pre-cooling failure, engine over temperature ..."
The atmosphere in the hall suddenly became tense.
Soon, the commander of the launch commander 01 issued: "110 suspend liquid oxygen discharge, suspend kerosene filling, each system remains in state, and will not enter the 60-minute program for the time being."
Pang Xuelin, Tao Yongchang and Liu Xuesong also stopped talking. The expression on Liu Xuesong's face was a little dignified and said, "Professor Pang, I'm sorry, I'll go over and see what happened first."
Pang Xuelin and Tao Yongchang looked at each other and quickly followed.
The experts in the hall of the command and control center quickly gathered and began to discuss the fault.
Pang Xuelin still has a certain understanding of the problem of engine pre-cooling failure and over-temperature.
For liquid oxygen kerosene engines and liquid hydrogen liquid oxygen engines, UU reading www.uukanshu. com low temperature propellant has a low boiling point and is in a gaseous state at room temperature. It is easy to vaporize during storage and transportation, and there is a gas-liquid two-phase flow, so it is easy to cause bad or even destructive to the engine and pressurized delivery system influences.
To avoid these effects, the engine should keep the propellant liquid during operation.
Therefore, the engine and its booster delivery system must be fully pre-cooled before starting.
Without pre-cooling, or insufficient pre-cooling, the temperature of the piping and pump components will be much higher than the temperature of the liquid propellant. In this way, when the engine is started, the propellant will be mixed in the gas phase or gas-liquid two-phase fluid. The state enters components such as pipes and pumps.
The engine and pump cannot work normally under this condition, which will cause cavitation, flying rotation of the pump, or prolong the start time and thrust climb time, resulting in pressure and flow fluctuations, stall operation, oxygen-rich combustion and other phenomena, serious You can make the startup completely fail.
The pre-cooling is to use the medium in the storage tank or other low-temperature medium on the ground to cool the conveying system and the engine before the engine is started, so as to reach the allowable temperature and ensure the reliable operation of the pump.
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