Medium and small hydraulic turbine runner static balancing test code
1 Scope
This standard specifies the balance method, balance quality grade and corresponding inspection method of static balancing of medium and small hydraulic turbine runner.
This standard is applicable to the inspection and acceptance of static balance quality of medium and small hydraulic turbine runners meeting one of the following conditions:
a) the power is 10 MW or below;
b) Francis and impulse turbines with runners of nominal diameter of 1.0 m or less;
c) axial and tubular turbines with runners of nominal diameter of 3.3 m or less.
Other types of turbine runners, flywheels, rotating oil basins and other turbine rotating parts may be used for reference.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition of the referenced documents (including any amendments) applies.
GB/T 2900.45 Electrotechnical terminology — Hydroelectric powerplant machinery
GB/T 6444 Mechanical vibration — Balancing vocabulary
GB/T 9239.1-2006 Mechanical vibration — Balance quality requirements for rotors in a constant (rigid) state — Part 1: Specification and verification of balance tolerances
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 2900.45, GB/T 6444 and GB/T 9239.1-2006 apply.
4 Application scope of runner static balancing, allowable amount of unbalance and balance quality grade
4.1 Application scope of runner static balancing
The application scope of the runner static balancing is expressed by the relation curve between the overall dimension ratio of the runner b/D (b is the height of the runner and D is the maximum outer circle diameter of the runner) (see Figure 1) and the runaway speed nrun(see Figure 2).
In Figure 2, the runner below the curve "1" only needs to be subjected to static balancing, while the runner above the curve "2" should conduct the dynamic balancing; and whether the runner between curve "1" and curve "2" is subjected to dynamic balancing depends on factors such as runner mass, manufacturing process, processing condition (partial processing or full processing) and bearing distance.
4.2 Runner mass and allowable amount of unbalance
Generally speaking, the greater the mass of the runner is, the greater the allowable amount of unbalance will be, so it may be expressed by Equation (1).
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Application scope of runner static balancing, allowable amount of unbalance and balance quality grade
4.1 Application scope of runner static balancing
4.2 Runner mass and allowable amount of unbalance
4.3 Runaway speed and allowable amount of unbalance
4.4 Balance quality grade
4.5 Allowable amount of unbalance
5 Static balancing
5.1 General
5.2 Horizontal static balancing
5.3 Vertical static balancing
5.4 Determination of unbalance
5.5 Error of allowable unbalance
6 Test report
Figure 1 Schematic diagram for the overall dimension b/D of turbine runner
Figure 2 Application scope curve of runner static balancing
Figure 3 Schematic diagram of horizontal static balancing device
Figure 4 Quality curve of static balancing test
Figure 5 Schematic diagram of static balancing test device for Francis turbine runner
Figure 6 Schematic diagram of static balancing test device for axial turbine runners
Figure 7 Sensitivity inspection for static balancing device
Table 1 Cutting edge width of knife-edge support
Table 2 Radius of the balance ball
Table 3 Distance h from the center of balance ball to the center of gravity of runner
