Selection Of Hydraulic Pumps In Wind Power Projects, And Anti-corrosion Of Bolts

(Last Updated On: October 13, 2021)

Where are wind power hydraulic wrenches mainly used for wind power?

Wind power hydraulic wrenches are commonly used in anchor bolts, blades to bearings, bearings to hubs, yaw drives, yaw bearings to foundation plates, yaw bearings to towers, main bearings to brackets, gearbox bases, and tower methods Installation and maintenance of flanges, shrink disks, hub adapters, main bearing brackets, variable pitch bearings to hubs, variable pitch drives, variable pitch bearings to blades, discs, etc.

In the wind power hoisting process, the hydraulic wrench system is a major tool and link for comparison. The foundation fixation, tower connection, blade device and nacelle device all use hydraulic wrenches. To some extent, it can be said that the stability of hydraulic wrench system will directly determine the progress of all lifting, so a high request is made for all hydraulic wrench systems, and in the hydraulic wrench system, the hydraulic station determines the stability of all hydraulic wrench systems.

So how to choose a special hydraulic station for hydraulic wrenches for wind power hoisting?

Requirements for the special hydraulic station for hydraulic wrenches for wind power hoisting:

1. Working at high altitude, the hydraulic station is easy to move;
2. The machine runs continuously for a long time and must be equipped with radiators;
3. The remote control button is used at a high frequency, and several spare buttons are needed;
4. Stable torque output, equipped with high-precision pressure gauge;
5. The hydraulic pump has stable functions and needs to be equipped with high-quality solenoid valves;
6. Voltage protection device, equipped with voltage stabilizer, stable voltage to 220 mA, stable voltage is a necessary condition for normal operation of hydraulic station.

Features of the special hydraulic station for hydraulic wrenches for wind power hoisting:

1. Equipped with 2 hydraulic wrenches (4 hydraulic wrenches of the same type can be equipped according to requirements);
2. Three kinds of pressure and three kinds of flow output are automatically switched, and the work efficiency is increased by 30%;
3. Solenoid valve imported from Germany, high quality;
4. High-precision pressure gauge to ensure high accuracy of wrench torque;
5. Automatically adjust the output pressure within the range of 40MPa-700MPa, reach the set pressure, and stop automatically;
6. Aluminum alloy fuel tank, equipped with high-function radiator, can run continuously;

Features of wind power hoisting work:

1. The equipment is used frequently and the work intensity is high. Because of the special structure of the wind turbine, the tower, nacelle, hub and blades are all connected by flange bolts, and the number of bolts is extremely large.
2. The power supply voltage is unstable. Most of the wind power installation sites use small gasoline and diesel generators, the voltage is very unstable, and the tower nacelle is usually above 70 meters, and the transmission line is long. Unstable voltage makes the hydraulic pump station unable to start, or leads to insufficient pressure.
3. Wind farms are mostly located in remote areas, Gobi, deserts and coastal areas, where there is a lot of wind and sand, severe corrosion, and harsh environment. After using the hydraulic wrench, the hydraulic station must be covered with a joint protective cap on the joint to prevent the entry of dust and stolen goods from affecting the use.
4. In the northern alpine zone, where the temperature is below minus 10°, or even below minus 20°, the hydraulic oil requirements are higher. In high-cold areas, please use low-temperature aviation hydraulic oil, and often replace the hydraulic oil in the hydraulic pump station, and clean all hydraulic systems frequently.

Precautions for the use of hydraulic pumps

1. Replace the hydraulic oil regularly, because of frequent long-term work, heavy sandstorms, rapid exhaustion of hydraulic oil and serious pollution. Replace the hydraulic oil once every 15 days. When the ambient temperature is higher than 30°, please use Mobil/Shell 46# wear-resistant hydraulic oil.
2. The selection of power generation equipment. It is recommended to use gasoline generators. The power cord should be a three-core cable with a single strand diameter of 4 mm or more to reduce line loss and slightly increase the output voltage of the generator to offset the line loss.
3. Take protection during transportation and tower work to prevent bumps. Turn on the electrical box regularly to check the components, fasten loose parts and replace damaged components in time. Note that the power supply must be cut off before turning on the electrical box. .
4. Operate and adjust the pressure according to the TorcStark hydraulic pump manual. After use, release the pressure to zero and close the switch of the electrical box. Adjust the high pressure regulator to make it in a loose state.

The use of hydraulic wrenches often causes damage to the bolts, or the bolts are corroded by the natural environment. This requires corrosion protection of the bolts.

Repair and anti-corrosion of bolts in wind power projects

After inspection, it was found that after several years of operation in many wind farms, large areas of high-strength connecting bolts and nuts exist in the tower.

Accumulate corrosion phenomenon, and the local corrosion area reaches more than 80%.

Through on-site disassembly, it was found that the top of the thread and the nut of the high-strength bolt were rusted, and there was basically no rust in other parts.

There is a problem of rust. At the same time, it was found that rust was also present locally in the bolt holes.

Communicate with the maintenance staff of the wind farm and learned that the bolts and nuts of the wind tower are carried out by special hydraulic torque tools.

Installed. In the process of installation and maintenance, the zinc layer on the surface of the bolts and nuts is damaged due to the torsion force applied by the torsion tool. In addition to the special humid environment of the wind field, the bolts and nuts rust in a short time.

The treatment plan is as follows

1. When newly installing and replacing fasteners, use cold galvanized aerosol for anticorrosion

After the installation is completed by the torsion tool, remove the rubbish and dust from the bolts and nuts, and spray directly with cold galvanized aerosol. If there is a damaged part on the flange of the tower, it can also be anti-corrosion by cleaning first and then spraying.

2. For bolts and nuts that have been corroded and rusted locally, the opportunity of daily maintenance can be used for anti-corrosion

In the process of daily maintenance and disassembly, the corroded and rusty parts are polished and rusted with a polishing tool, and then the cold is directly used.
Galvanized aerosol paint is sprayed or brushed.

3. Surface treatment:

For the newly installed or unrusted bolt and nut surface, if there is no oil and dust, Robaru cold galvanizing can be used directly.
The paint is sprayed or brushed. For the surface of bolts and nuts that have been rusted, during the installation and inspection process, it is necessary to use.
Electric grinding tool for grinding and rust removal. If there is dust and oil on the surface of the parts, they need to be cleaned up.

4. Spraying method and film thickness

After finishing the surface treatment, please spray Robaru cold galvanized paint to cover it in time. Pay attention to the coating quality and ensure the film thickness. one
It is generally recommended that the film thickness is not less than 80 μ m (if the components are to be tested for disassembly and assembly every year, the film thickness can be reduced)