[Explanation] At the end of December, when entering the installation room of the Liujiaxia Hydropower Plant, the sound of "bumping" and "sizzling" electric drills were mixed, and the maintenance work extended from the surface to 20 meters underground.
Lu Jianming, an overhaul of the "post-90s" hydraulic turbine team, and his colleagues walked down the narrow aisle and walked down the stairs to the manhole door with a diameter of only one meter.
Buckle the inside of the door frame, vacate your feet, shrink into a ball and get into the volute. The seemingly simple action is still not a small challenge for Lu Jianming, who has only worked for two months.
[Concurrent] Lu Jianming, maintenance worker for hydraulic turbines of Liujiaxia Hydropower Plant
When I entered the volute door for the first time, I came down with our master. The moment I entered the door, I almost got stuck at the door. After I entered, I found that it was darker inside and felt damp, which made people tremble. That feeling.
[Explanation] Liujiaxia Hydropower Plant is located in the upper reaches of the Yellow River. It mainly generates electricity and has integrated functions such as flood control, irrigation, snow prevention, and aquaculture. It is the first large-scale hydropower plant in China with a megawatt level.
In large-scale equipment, the volute is an important water-conducting device, so named because it looks like a snail shell.
During the temporary inspection, the maintenance personnel will inevitably open the volute to check the abrasion of the buried parts and the flow-through parts, and formulate a repair plan.
The inside of the volute is dark and damp, and the inner wall is inclined and smooth, making it difficult to carry out maintenance work.
Because of this, Lu Jianming calls the maintenance workers the "internal physicians" of the hydropower station.
[Concurrent] Lu Jianming, maintenance worker for hydraulic turbines of Liujiaxia Hydropower Plant
The charm of this job is like our physicians, to see the hydraulic turbine, its every structure, every part, and how it works, (we) let it run safely and stably.
[Explanation] Liujiaxia Hydropower Plant's turbine team leader Pu Qiang said that in the winter dry season, Liujiaxia Hydropower Plant will enter the busy time of "full physical examination" and "rehabilitation" of the unit, and the turbine is the "heart" of the unit, and they are responsible for the equipment installation The accuracy is required to be one-sixtieth of the hair, and if there is a slight error, the consequences are unpredictable.
[Concurrent] Pu Qiang, monitor of the turbine team of Liujiaxia Hydropower Plant
In the specific operation, for example, the accuracy of our operation is one-sixtieth of a hair strand. If there is no such accuracy to ensure the operation of our unit, it is possible that during the rotation process, the unit will Lubrication, sealing, and structural defects occur.
[Explanation] The operation accuracy mentioned by Pu Qiang refers to the standard for repairing and reinstalling hydraulic turbine parts. Because the equipment is under water, the maintenance parts must be tightly fitted with the main body. If there is a slight deviation, the standby unit will vibrate at high frequency, which will cause water leakage and turbine swing. Unsafe phenomena such as deviation from the center directly threaten the safe and stable operation of the unit.
Kong Quanyou, who has been working in overhaul jobs for more than 30 years, has witnessed the process from manual overhaul to machine assistance.
[Concurrent] Liujiaxia Hydropower Plant Turbine Shift Maintenance Worker Kong Quanyou
For example, the screws on the door (above) of our volute are also relatively large. (Previously) it was driven out by a human being with a hammer. It relied on the crowd tactics. Many were not tight. There were many cases of maintenance and rework.
Now we basically use good torque wrenches, electric wrenches, and elastic bolts with high accuracy.
[Explanation] Li Yongqing, director of the Liujiaxia Hydropower Plant, said that in the past three years, the upper reaches of the Yellow River have received a lot of water and the pressure of flood prevention is high. The plant will conduct large-scale maintenance every year to prepare for the safe operation of equipment in the coming year.
[Concurrent] Li Yongqing, Director of Liujiaxia Hydropower Plant
In addition to generating electricity, Liujiaxia Hydropower Plant also has comprehensive functions such as flood control, anti-freezing, irrigation, frequency regulation, and voltage regulation. In addition to equipment capacity expansion and transformation, we also use new technologies and new materials to improve the health and automation level of equipment. The number of safe (production) days exceeds 7000 days.
Ai Qinglong and Yan Jiao report from Linxia, Gansu
Editor in charge: [Song Fangcan]