GB/T 41850.5-2026Mechanical vibration - Measurement and evaluation of machine vibration - Part 5: Machine sets in hydraulic power generating and pump-storage plants (English PDF)

Foreword

This document conforms to GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents".

Drafting is scheduled.

The following parts were included.

--Part 1: General Provisions;

--Part 2: For 40 MW and above, using sliding bearings, the rated speeds are 1500 r/min, 1800 r/min, and 3000 r/min.

And 3,600 r/min land-based gas turbines, steam turbines, and generators;

--Part 5: Hydropower and Pumped Storage Power Station Units;

--Part 8: Reciprocating Compressor Systems;

--Part 9: Gear Gear

This document replaces GB/T 11348.5-2008 "Measurement and evaluation of radial vibration of rotating machinery shafts - Part 5: Hydropower plants".

"Measuring and evaluating mechanical vibrations of machines on non-rotating parts - Part 5: Hydraulic vibrations" and GB/T 6075.5-2002 "Measuring and evaluating mechanical vibrations of machines on non-rotating parts - Part 5: Hydraulic vibrations".

"Power Plant and Pumping Station Units" has undergone structural adjustments and editorial changes compared to GB/T 11348.5-2008 and GB/T 6075.5-2002.

In addition, the main technological changes are as follows.

--The vibration measurement evaluation area has been changed (see 6.2, Appendix A of GB/T 11348.5-2008 and GB/T 6075.5-2002).

Chapter 5);

--Added boundary limits for the A-B/C and C/D regions of bearing housing and shaft vibration under given operating conditions (see Chapter 6);

--Added requirements to the vibration zone boundary evaluation, specifying that the bearing temperature should not exceed the specified limit and the shaft vibration displacement should not exceed the bearing's cold state value.

70% consideration for radial clearance (see Chapter 6);

--Added various measures to be taken when vibration exceeds the limits in the A-B/C and C/D zones (see A.3).

This document is equivalent to ISO 20816-5:2018 "Mechanical vibration – Measurement and evaluation of machine vibration – Part 5: Hydroelectric power generation and..." Pumped storage power station units.

This document was proposed and is under the jurisdiction of the National Technical Committee on Standardization of Mechanical Vibration, Shock and Condition Monitoring (SAC/TC 53).

Introduction

This document provides specific methods for measuring and evaluating the vibration of bearing housings and shafts in hydroelectric and pumped-storage power plants.

Physical guidance.

This document provides two criteria for assessing machine vibration.

a) The first criterion takes into account the amplitude of the measured vibration;

b) The second criterion takes into account the changes in the amplitude and phase of the measured vibration.

This document covers the analysis of vibrations of rotating shafts and vibrations of fixed, non-rotating components.

This document establishes vibration criteria for horizontal and vertical axis machines, and provides guidelines for each type of turbine (bulb turbine, mixed-flow turbine, bucket turbine, shaft turbine).

Vibration criteria have been established for propeller-driven pumping turbines in both power generation and pumping operations (depending on the specific conditions). The vibration amplitude criteria provided in this document are based on a unified...

Based on calculations, the given amplitude values are not suitable as guarantee values. It is recommended that a vibration assessment be conducted by a vibration expert jointly selected by all parties.

To determine the optimal performance of hydraulic machinery, the following points need to be considered comprehensively.

--Relative shaft vibration value;

--Vibration value of bearing housing;

--Percentage of the cold radial clearance of the guide bearing used;

-- Ensure that the machine's operating conditions (head and flow rate or head and power) are within the normal operating range.

For vibration amplitudes exceeding the action limits given in Appendix A, recommended measures are provided to determine whether the machine is suitable.

It can operate continuously and for a long time without restrictions.

This document provides details regarding vibrations that occur during machine operation, as well as any possible changes in the amplitude or phase of the vibration values.

Guidelines. The vibration values given in Appendix A are intended as a basis for assessing machine condition and for further investigation as necessary.

This document recommends assessing machine condition by simultaneously considering bearing housing vibration and shaft vibration.

GB/T 41850 "Mechanical Vibration - Measurement and Evaluation of Machine Vibration" provides guidelines for the measurement and evaluation of vibration on non-rotating parts and rotating shafts.

Requirements and guidelines for machine vibration. GB/T 41850 is proposed to consist of the following parts.

--Part 1: General Principles. The purpose is to provide a framework for measuring and evaluating various types of machine vibrations on non-rotating parts and rotating shafts.

General requirements.

--Part 2: For 40 MW and above, using sliding bearings, the rated speeds are 1500 r/min, 1800 r/min, and 3000 r/min.

And a land-based gas turbine, steam turbine, and generator with a speed of 3600 r/min. The aim is to provide information on large-scale land-based gas turbines...

Specific evaluation of vibration of bearing housings and shafts in turbines, steam turbines, and generators.

--Part 4: Gas turbines with fluid diaphragm bearings above 3 MW. The purpose is to provide the normal operating speed range...

Specific details of land-based gas turbines using fluid diaphragm bearings with speeds ranging from 3,000 r/min to 30,000 r/min and output power greater than 3 MW.

evaluate.

--Part 5: Hydropower and Pumped Storage Power Plant Units. The purpose is to provide information on the bearings of hydropower and pumped storage power plant units.

Guidelines for measuring and evaluating seat vibration and shaft vibration.

--Part 8: Reciprocating Compressor Systems. The purpose is to provide procedures for the measurement and classification of mechanical vibration in reciprocating compressor systems.

--Part 9: Gear Gears. The purpose is to provide specifications for enclosed, single-casing speed-increasing or speed-reducing gear gear systems.

Specific requirements for measuring and classifying mechanical vibrations.

--Part 21: Horizontal Axis Wind Turbines. The purpose is to provide information on the measurement and evaluation of mechanical vibrations in wind turbines and their components.

Estimate the information.

Measurement and evaluation of mechanical vibration.

Part 5: Hydropower and Pumped Storage Power Station Units

1 Scope

This document provides information on bearings, bearing supports, or bearings of hydroelectric and pumped storage power station units during normal operation.

Evaluation guidelines for absolute vibration measurement at the base and relative shaft vibration measurement. This document covers the normal operation of each type of turbine.

See Appendix A for the scope.

This document applies to hydroelectric and pumped storage power station units with typical operating speeds of 60 r/min to 1000 r/min and cylindrical bearings.

Type or segmented bearing with oil lubrication.

Note. The current database includes units with speeds ranging from 60 r/min to 750 r/min (with only a small number of 1000 r/min units as samples).

This document defines bearing housing vibration and, based on the type of turbine, the direction of the shaft (i.e., horizontal or vertical), and the location of each bearing, the vibration of the bearing housing and...

Different limits for shaft vibration.

This document, based on statistical analysis, provides guidelines for the most common types of water turbines, pumps, and turbines. (The document also covers...) for specific information on the unit type, please refer to Appendix A.

The units covered in this document may have the following configurations.

a) A generator driven by a water turbine;

c) An electric generator driven by a water turbine or an independent pump;

d) Pumps driven by electric motors.

This document does not apply to the following unit configurations, parameters, and operating conditions.

--Hydraulic machines using water-lubricated bearings;

--Hydraulic machines or units using rolling bearings (for these machines, see IEC 62006 and/or ISO 10816-3).

-- Pumps in thermal power plants or industrial equipment (for these machines, see ISO 10816-7).

--Except for motors that operate as electric motors in pumped storage applications;

--A hydro-generator that operates as a synchronous condenser (water in the turbine is forced out by compressed air);

--Evaluation of the absolute vibration displacement of the bearing housing;

--Evaluation of axial vibration;

--Evaluation of transient operating conditions;

--Run asynchronously;

--Evaluation of the vibration level of the generator stator core or stator frame.

Vibration measurement of bearing housings and shafts in hydroelectric and pumped storage power station units can be used for the following purposes.

a) Purpose A. To prevent damage caused by excessive vibration amplitude;

b) Objective B. To monitor changes in vibration characteristics in order to make diagnoses and/or predictions.

This document applies to vibrations generated by the unit itself. Vibrations transmitted to the unit from external sources require specific study, such as...

The vibrations transmitted from the power station foundation to the machine.

2 Normative references