NB/T 11191-2023
Technical Guidelines for Resisting Sediment Wear of Turbines in Hydropower Stations (English Version)
- Standard No.
- NB/T 11191-2023
- Language
- Chinese, Available in English version
- Release Date
- 2023
- Published By
- Professional Standard - Energy
- Latest
- NB/T 11191-2023
- Introduction
Standard Background and Technology Evolution
This guideline is based on the 2018 Energy Bureau Standard Revision Plan (National Energy Comprehensive Technology [2018] No. 100), integrating the anti-wear practices of mixed flow, axial flow and impact turbines, and systematically proposed the wear prediction model (Formula A.1) and the overhaul cycle calculation formula (A.9) for the first time. Compared with the international standard IEC62364, special requirements for China's high-sand content water flow have been added.
Comparative analysis of key indicators
Wear level Efficiency reduction limit Maintenance cycle Coating damage rate Minor Large ≤1% Small ≤2% ≥7 years - Medium Large ≤1% Small ≤3% ≥5 years ≤5% Severe Large ≤1% Small ≤3% ≥3 years ≤10%
Core technical requirements
1. Wear prediction method
The wear depth is calculated using the formula S=W3.4×PL×Km×Kf/RSp, where:
- WCharacteristic flow velocity: mixed flow impeller outlet ≤40m/s
- PLSediment load: Mineral content with Mohs hardness>5 needs to be measured
- KfFlow coefficient: guide vane is 1.06×10-9
2. Material selection specifications
06Cr13Ni4Mo stainless steel is the reference material (Km=1), and the wear loss of carbon steel needs to be doubled (Km=2). Tungsten carbide coating requirements:
- Bonding strength ≥ 70MPa
- Porosity < 1%
- Hardness ≥ 1100HV0.3
Implementation suggestions
1. Design stage
- Reducing the specific speed by 10-15% can reduce the wear by 30% (Formula A.7)
- The outlet diameter of the mixed flow runner should be reduced by 5-8%
2. Operation stage
When the sand content exceeds the design value by 20%, it is recommended to start the peak avoidance operation procedure. A power station case shows that peak avoidance operation can extend the overhaul period by 42% (Table A.2).
3. Maintenance strategy
Adopt graded maintenance: Grade A maintenance requires measuring the thickness of the blade outlet edge (standard value ≥ 2/3 of the original thickness), and grade C maintenance focuses on checking the depth of the anti-wear plate groove (limit value ≤ 8mm).
NB/T 11191-2023 Referenced Document
- DL/T 1066 Hydropower station equipment maintenance management guidelines*， 2023-10-11 Update
- GB/T 11373 Thermal spraying—Pre-treatment of surfaces of metallic parts and components
- GB/T 11374 Thermal spraying coating.Nondestructive methods for measurement of thickness
- GB/T 15468 Fundamental technical requirements for hydraulic turbines
- GB/T 15749 Measuring method in quantitative metallography
- GB/T 2900.45 Electroltechnical erminology Hydroelectric powerplant machinery
- GB/T 4340.1 Vickers hardness test for metallic materials Part 1: Test method*， 2024-05-28 Update
- GB/T 8642 Thermal spraying--Determination of tensile adhesive strength
- NB/T 10135 Basic technical specifications for large and medium hydraulic turbines
- NB/T 35049 Code for sediment design of hydropower projects
NB/T 11191-2023 history
- 2023 NB/T 11191-2023 Technical Guidelines for Resisting Sediment Wear of Turbines in Hydropower Stations
