Views:114 Author:Site Editor Publish Time: 2019-04-22 Origin:Site
Suggestions based on current realities:
1. From the current situation reflected in all aspects, it is imperative for the wind turbines that have been put into operation to find the harbinger of the bearing running circle in time before the destructive accident. This can eliminate the accident in the bud. However, due to the different structure of the wind turbine, the operating environment is different, the bearing positions are different, and the vibration characteristics of various types of bearing running rings have not been mastered technically. What can be done at present is to collect the vibration monitoring records of wind turbines that have already had accidents, organize professional teams to analyze them, find out the regularity items as soon as possible, and then verify and promote them in the running wind farm. There are already a number of manufacturing companies, development and operation companies and research institutions expressed their willingness to participate and provide verification conditions.
2. The analysis in front of this report is based only on previous theories, experiences and available cases. The current large number of accidents have not yet been fully grasped. In order to conduct an accident analysis, each gearbox manufacturer should no longer use the pretext of keeping the so-called “trade secrets” as an excuse to refuse public accidents. The result of this can only cause deeper damage to China’s wind power industry. Only by thoroughly grasping the real situation of the accident in the industry and thoroughly analyzing the possible causes can we find the root cause of the defect and take effective measures to solve it. At the same time, provide basic data for mastering accident monitoring and early warning technology. It is recommended that all enterprises involved in similar accidents should truthfully provide accidents to the whole machine enterprises, development and operation enterprises and research institutions.
3. Bearings should be equipped with sufficient tooling to prevent invisible damage during assembly. The assembly with interference fit is preferably to uniformly heat the bearing by a closed heating device. The heating temperature should not be too high, and it is in a positive clearance state during the heating process, and does not squash the roller and deform. When conditions permit, it is recommended to assemble the bearing by means of a freezer shaft. The lubrication of the bearings should be highly valued. In addition to ensuring adequate lubrication, adequate measures must be taken to ensure the cleanliness of the fluid.
4. In the selection of bearings and their cooperation, the host and components and the bearing supply unit should work closely together, timely exchange and feedback, and reasonable selection of bearings and cooperation. The shaft and hole of the bearing of the device should be selected according to the tolerance of the diameter of the bearing ring, and the tolerance range should be properly tightened to ensure the interference of the fit.
5. Strengthen the training and training of professional and technical workers to ensure that the assembly and clearance adjustment of the bearings meet the technical requirements.
6. During the assembly process, the shafting should be centered repeatedly to mitigate the effects of additional loads.
7. Strengthen the processing of gearbox, the technical procedures of the assembly site, the process hygiene management, ensure the processing of the gearbox, and the assembly process is carried out under strict process conditions.
8. Prepare technical guidelines related to the transportation and storage of wind turbines and main shafts to prevent deformation of the lower end raceways and rollers of the main shaft bearings due to the large gravity of the main shaft during transportation and non-operational stages.
9. Enhance the rigidity of the wind turbine frame to prevent abnormal eccentric load of each bearing caused by deformation.
10. Strengthen the daily maintenance of wind turbines, strictly abide by the safe operating regulations, and have sufficient countermeasures for the impacts of different processes such as starting, braking, stopping, and deactivating the unit.
11. The wind turbine should be equipped with relevant detection devices to perform instantaneous monitoring of the vibration and temperature of the transmission system, analyze the measurement data, accurately find the cause, and issue an early warning to avoid downtime due to failure.
12. Strengthen the design research of wind turbines. Based on the reliability analysis, the system analyzes the impact of the abnormal transient load on the key parts of the transmission system for the severe working conditions of the unit, and compiles the load spectrum that is more in line with the actual working conditions. Fully guarantee the safety margin of the system and components. Improve the layout and structure of the drive system to reduce the effects of transient anomalous shock loads.
13. Reasonably select the structural form of the unit transmission system on the basis of accumulated experience, and adopt the mature and proven transmission form as much as possible. The new transmission form and structural arrangement should not be easily adopted without demonstration.
14. The original bearing life calculation theory has been difficult to meet the requirements of modern wind turbine gearbox bearing calculations. The relevant information manufacturer of the new bearing life calculation method proposed by the international famous bearing company is generally less public. At present, the calculation of bearing life is generally estimated based on the life calculation method proposed by each bearing manufacturer. Bearing life calculation methods are numerous, the influencing factors are complex, the load data is scarce, and the complex load processing methods are imperfect. The processing of transient loads, braking loads, ultimate loads, etc., which are often encountered during the use of the unit, is estimated empirically. In addition, the linear cumulative damage theory used in the process of variable load processing does not truly reflect the actual damage, which will lead to an increase in the gap between design calculation and practical application. To this end, it is recommended to strengthen the research on the theory of domestic bearing life in combination with the actual needs of wind turbines.
15. It is recommended to strengthen the research on bearing design, materials, technology and inspection technology in the special field of wind power high load capacity, high reliability and long life as soon as possible. The bearing industry and wind turbine manufacturing enterprises, wind power transmission equipment manufacturing enterprises jointly carry out research work, accumulate experience for the design and manufacture of wind power bearings, and strive to make breakthroughs as soon as possible.