GB/T 15468-2020Fundamental technical requirements for hydraulic turbines (English PDF)

3.3 Turbine head

3.3.1 Head The effective head of the hydraulic turbine, which is the total unit energy of the high and low pressure reference cross-section of the turbine.

Note. The unit is meter (m).

4.1 General requirements

4.1.1 The design and manufacture of hydraulic turbines shall be based on the characteristics and basic parameters of the hydropower station, to optimize the type and main parameters of the turbine, to ensure the safe, reliable, stable, efficient operation of the turbine.

4.1.4 For the design of hydraulic turbine, it shall provide the type, layout, model, as well as the following basic parameters.

4.1.5 The following technical documents shall also be given for the design of the turbine.

4.1.6 The efficiency correction of the reaction turbine is to be corrected, according to the formula in Appendix A. The efficiency of the impulse turbine is generally not corrected; however, if correction is required, it shall be carried out in accordance with Appendix B.

4.2.1 General requirements for structural design

4.2.1.6 The standard parts and components of hydraulic turbines shall ensure their universality, for example, use runner whose torque is transmitted by friction; nozzles, needles shall be interchangeable.

4.2.1.7 The allowable continuous running time of the turbine, at the maximum runaway speed, shall not be less than the allowable runaway time of the supporting generator. Meanwhile, it shall be ensured that the rotating parts of the turbine NEITHER produces harmful deformation NOR causes collision and damage. Facilities shall be provided to prevent the turbine from exceeding the allowable runaway time.

4.2.1.22 The metal volute of the reaction turbine and the water distribution pipe of the impulse turbine, may be subjected to a pressure test, according to the requirements of the contract.

4.2.2 Working stress and safety factor

4.2.2.7 Unless otherwise specified, where there is no prestressing requirement, the pre-tightening force shall not be less than

2.0 times the maximum working load of the connected object, under normal working conditions and transitional working conditions, which is converted to the axial load of the bolt.

4.3.4 Impulse turbine

4.3.4.1 It shall be possible to assemble, disassemble, replace the runner of the impulse turbine, without disassembling the generator.

4.3.4.2 The runner shall be subjected to dynamic response analysis, to avoid resonance.

5.2 Steady-state hydraulic performance

5.3.3 When the content of sediment in the water is high, the abrasion damage of the turbine shall be guaranteed.

5.5 The stable operating range of turbine

5.5.1 Within the range of maximum and minimum heads, which are specified in 4.1.4, the power range for stable operation of the turbine is in accordance with Table 5.

5.7 Water leakage of guide vanes or nozzles

5.7.1 Under the rated water head, for the newly commissioned unit, the water leakage of the guide vanes of the cylindrical arrangement shall not be greater than 0.3% of the rated flow of the turbine; the water leakage of the guide vanes of the conical arrangement shall not be greater than 0.4% of the rated flow of the turbine.

5.8 Noise When the turbine is operating normally within the stable operating range, the noise, which is measured 1 m above the enclosure of the impulse turbine, shall not be greater than 85 dB(A). The noise, which is measured within 1 m around the runner chamber of the bulb turbine, shall not be greater than 90 dB(A). The noise, which is measured 1 m above the floor of the turbine pit for other types of units, shall not be greater than 95 dB(A). The noise, which is measured 1 m away from the manhole of the tail water tube, shall not be greater than 95 dB(A).

5.9 Water thrust For the reaction turbine, it shall guarantee the maximum forward water thrust and maximum reverse water thrust, under normal working conditions and transitional working conditions.

7.1 Scope of supply

7.1.1 For Francis turbine, it includes tail water tube's metal lining, metal volute and volute extension (if any), seat ring, base ring, water guiding mechanism, thrust bearing bracket (if any), cylindrical valve system (if any), runners, turbine shafts, water guide bearings, working seals, overhaul seals, turbine pit linings, connections between parts, turbine pit lighting devices, air supplement systems, pedestrian pedals and handrails, portable overhaul platforms in tail water tube, drainage equipment, other supporting equipment, etc.

7.1.4 For the impulse turbine, it includes the metal lining of the tail water sump, water stabilizing grid, water distribution ring pipe, enclosure, enclosure cover, nozzle (including the nozzle ring, nozzle port, nozzle tube, needle, needle servomotor, protective cover, etc.),

7.1.6 Piping and its accessories. All oil pipes, air pipes, water pipes, water supply equipment for main shaft seal, connectors, brackets, which are required in or between the parts within the scope of the contract.

7.1.7 Dedicated tools and special tools, which are required for installation and maintenance.

7.1.8 The instruments and equipment, which are required for the acceptance test of the prototype turbine, shall be negotiated between the supplier and the buyer.

7.3 Spare parts and components For the items and quantities of spare parts and components for hydraulic turbines, they are selected with reference to Tables E1, E2, E3, E4 in Appendix E. Meanwhile, it shall be specified in the contract, between the supplier and the buyer.

8.2 Key items

8.2.1 Layout drawing of hydraulic turbine and its auxiliary equipment, regulation guarantee calculation report.

8.2.5 The relationship diagram BETWEEN guide vane opening or rotation angle or nozzle stroke AND servomotor stroke; the basic force data; other important calculation reports of the turbine, etc.

8.2.6 The technological process, drawings, documents related to the arrangement, assembly, welding, processing of the turbine and its auxiliary equipment on the site.

8.2.7 Control and monitoring. Installation and layout diagrams of various panels and automation equipment; automatic operation of hydraulic turbines and system diagrams of oil, gas, water; configuration diagrams of hydraulic turbine measuring instruments, etc.