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GB/T 50700-2022: Standard for technical renovation of small hydropower station
Status: Valid GB/T 50700: Evolution and historical versions
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Standard for technical renovation of small hydropower station
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Basic data | Standard ID | GB/T 50700-2022 (GB/T50700-2022) | | Description (Translated English) | Standard for technical renovation of small hydropower station | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | P59 | | Word Count Estimation | 54,528 | | Date of Issue | 2022-07-15 | | Date of Implementation | 2022-12-01 | | Issuing agency(ies) | Ministry of Housing and Urban-Rural Development of the People's Republic of China; State Administration for Market Regulation | | Summary | This standard applies to the technical transformation of small hydropower stations with a single station installed capacity of 500kW~50000kW. | GB/T 50700-2022: Standard for technical renovation of small hydropower station---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
1 General
1.0.1 This standard is formulated in order to standardize the technical transformation of small hydropower stations, promote the technological progress of power stations, scientifically utilize hydropower resources, eliminate potential safety hazards, ensure safe operation, improve production technology and energy efficiency, and improve the ecological environment.
1.0.2 This standard applies to the technical transformation of small hydropower stations with a single station installed capacity of 500kW~50000kW.
1.0.3 The technological transformation of small hydropower stations should follow the principles of safety, reliability, environmental protection, reasonable technology, and economical applicability, make full use of existing facilities or equipment of hydropower stations, and actively adopt mature new technologies, new processes, new equipment, and new materials.
1.0.4 Before the technical transformation of small hydropower stations, relevant design reports should be compiled. When the electromechanical equipment conforms to the current national standard "Small Hydropower Station Electromechanical Equipment Scrap Conditions" GB/T 30951, it should be scrapped and updated in time.
1.0.5 The technical transformation of small hydropower stations shall not only comply with this standard, but also comply with the relevant current national standards and meet the needs of river channel ecological flow discharge.
2 terms
2.0.1 Technical renovation
Taking technical measures to rebuild, update, increase or reduce the capacity of small hydropower station facilities or equipment, and improve its reliability, economy, rationality and advanced nature.
2.0.2 Renovation by renewal of equipment
Activities to update small hydropower plant facilities or equipment in order to improve facility or equipment performance, increase efficiency and reliability.
2.0.3 Renovation for increasing installed capacity
It is an activity to carry out technological transformation of electromechanical equipment, increase the installed capacity of the power station, improve performance, and increase efficiency and reliability.
2.0.4 Renovation for decreasing installed capacity
Carry out technological transformation of electromechanical equipment, reasonably reduce the installed capacity of power stations, improve performance, optimize operating areas, and improve efficiency and reliability.
3 Status Analysis and Evaluation
3.0.1 The following data should be collected for technical transformation of small hydropower stations.
1 Engineering design, completion and operation data;
2 hydrological and sediment data;
3 Safety testing and performance testing or evaluation data;
4.Other relevant information.
3.0.2 Before the technical transformation of small hydropower stations, safety analysis should be carried out on hydraulic structures, hydraulic machinery, electrical, metal structures and other facilities or equipment based on safety inspection or evaluation results, operation and maintenance data, and the necessity of technical transformation should be determined. evaluate.
3.0.3 Before the technical transformation of small hydropower stations, the water resource utilization conditions shall be analyzed and evaluated according to the river planning and the latest hydrological data, and the following contents shall be included.
1 Review runoff and flood when necessary;
2 Possibility of increase and decrease of working water head and flow;
3 Amount of discarded water available;
4 Conditions for reducing head loss and flow loss;
5 Ecological flow and discharge facilities.
3.0.4 The performance evaluation of facilities or equipment shall be made based on the preventive test report or the current performance test results.
3.0.5 Analyze the operation data and maintenance data of the power station, and combine the hydrological data to study the change law of the water level, water head, flow, ecological flow, sediment content, etc. in the upstream and downstream of the power station, and demonstrate the necessity and feasibility of the power station transformation.
4 performance test
4.0.1 For hydro-generator units with a unit capacity of 10,000kW and above, performance comparison tests shall be carried out before and after technical transformation.
4.0.2 Turbine performance test should be carried out in accordance with the specific circumstances, according to the relevant provisions of the current national standard "Site Acceptance Test Regulations for Small Water Turbines" GB/T 22140 or "Hydraulic Turbines, Storage Pumps and Pump Turbines Hydraulic Performance Field Acceptance Test Regulations" GB/T 20043.
4.0.3 For the power station where the main mechanical and electrical equipment exceeds the design service life or affects the safe operation, and abnormal conditions occur, the inspection and evaluation shall be carried out according to the current national standard "Small Hydropower Station Safety Inspection and Evaluation Specification" GB/T 50876.
4.0.4 The detection of steel gates and hoists can be carried out in accordance with the relevant provisions of the current industry standard "Technical Regulations for Safety Inspection of Hydraulic Steel Gates and Hoists" SL101.The inspection of penstocks can be carried out in accordance with the relevant provisions of the current industry standard "Technical Regulations for Safety Inspection of Penstocks" NB/T10349.
4.0.5 For the performance test of the main electrical equipment of small hydropower stations, the preventive test report or the current performance test results can be used before the transformation. After the transformation, the test and acceptance should be carried out according to the current national standard "Electrical Equipment Handover Test Standard for Electrical Installation Engineering" GB 50150.
4.0.6 The detection and evaluation results shall be used as the basis for determining the necessity of technological transformation of small hydropower stations, the transformation plan and the assessment of the effectiveness of technological transformation.
5 Transformation content and requirements
5.1 General provisions
5.1.1 When one of the following situations occurs, technical transformation shall be carried out.
1 There are potential safety hazards;
2 Large changes in the upstream and downstream hydrological characteristic parameters;
3 Unreasonable utilization of water energy resources;
4 The quality of civil construction, equipment manufacturing or installation is poor, the performance of equipment is backward, and the technical condition is poor;
5 Changes in geological conditions;
6 No ecological flow discharge facilities;
7 Electromechanical equipment meets the scrapping conditions;
8 Other situations that require modification.
5.1.2 The usable part of the existing facilities and equipment shall be reviewed and calculated as necessary, and corresponding technical processing shall be carried out if necessary.
5.1.3 Small hydropower stations with a lot of discarded water can be expanded and transformed. During the transformation, the impact of the discharge of ecological flow on the installed capacity should be considered, the installed capacity should be reasonably determined, the reference flow, head loss, structural strength, hydraulic transition process, etc. of the water diversion system should be reviewed and calculated, and other equipment and facilities should be reviewed.
5.1.4 Power plants with low annual utilization hours, reduced water head or flow can be converted to capacity reduction. "Technical Transformation Standards for Small Hydropower Stations" GB/T 50700-2022
5.2 Hydraulic structures
5.2.1 The technical transformation of hydraulic structures shall meet the following requirements.
1 Eliminate potential safety hazards;
2 The submergence loss is small;
3 It is convenient for construction.
5.2.2 The following transformation measures can be taken to improve the utilization of water energy resources.
1 Heighten the dam;
2 Additional facilities such as rubber dams, flap gates or controllable gates;
3 Increase the capacity of the forebay;
4 Lower the tail water level of the unit.
5.2.3 For small hydropower stations with increased total storage capacity, the project grade, building grade and flood standards should be reviewed.
5.2.4 The safety monitoring and renovation of hydraulic structures should comply with the relevant provisions of the current industry standard "Code for Design of Safety Monitoring of Water Conservancy and Hydropower Projects" SL725, improve the safety monitoring system of reservoir dams, and the water level information of the reservoir should be transmitted to the central control room of the power station or mobile communication equipment.
5.2.5 The seismic fortification of small hydropower stations shall comply with the relevant provisions of the current industry standard "Code for Seismic Design of Hydraulic Structures" SL203.
5.2.6 The following measures can be taken for the technical transformation of the diversion channel system.
1.Improve the sand discharge and pollution control facilities at the head of the water diversion system;
2 Increase the cross-section of the water and reduce the roughness;
3 Anti-seepage treatment of water diversion structures;
4 Tail water clearance and dredging, improving the water flow pattern of the tail water channel.
5.2.7 In cold areas, anti-freezing facilities should be added to hydraulic structures and metal structural equipment.
5.2.8 The technical transformation of gates and hoists shall meet the following requirements.
1 Technical transformation shall be carried out for all kinds of gates with defects such as corrosion, deformation, vibration and serious water leakage and inflexible opening and closing equipment to eliminate defects;
2 For gates with excessively increased opening and closing force due to corrosion, deformation, etc., new supporting materials should be used first to reduce friction, and the support form or opening and closing equipment of the gate can also be improved;
3 For small hydropower stations with heightened dams, the existing gates and opening and closing equipment should be reviewed or reinforced.
5.2.9 It is advisable to set water-filling hydraulic pressure facilities for the emergency maintenance gate of the water inlet of the unit and the tail water maintenance gate. The tailgate should not be filled with upstream water for hydraulic pressure.
5.2.10 The opening and closing equipment of the flood gate shall have reliable backup power.
5.2.11 The technical transformation of pressure piping shall meet the following requirements.
1 The water-stop ring of the expansion joint with serious water leakage and aging should be replaced;
2 When the steel pipe is severely corroded or damaged to the extent specified in the current industry standard "Water Conservancy and Hydropower Engineering Metal Structure Scrap Standard" SL226, it should be replaced;
3 The township and buttresses with uneven settlement shall be reinforced;
4 Reinforced concrete pipelines with severe aging should be replaced;
5 If the diameter of the pressure pipe is too small, the pipe should be increased or the pipe diameter should be increased.
5.2.12 The technical transformation of the plant shall meet the following requirements.
1 Improve flood control facilities to meet flood control requirements;
2 The strength of machine pier, crane girder and bent frame should be rechecked for capacity expansion and reconstruction of the power station, and the strength of floor slabs with increased load should also be rechecked;
3 The requirements for safe operation, maintenance and overhaul of electromechanical equipment shall be met;
4 The appearance of the factory building is adapted to the surrounding environment.
5.3 Turbine and its auxiliary equipment
5.3.1 The technical transformation of the turbine shall meet the following requirements.
1 The selected turbine runner model should have advanced energy index, excellent cavitation characteristics, and good operation stability;
2 When selecting the main parameters of the turbine, the water diversion system of the hydropower station, the size and installation elevation of the turbine flow channel, and the generator parameters should be considered to ensure that the turbine operates in a stable and high-efficiency zone, and the suction height meets the requirements;
3.The water turbine should be adapted to the change of water head and flow, improve the operating conditions, and improve the stability and efficiency of operation;
4 For a hydropower station with a lot of sediment, the sand wear of the turbine should be evaluated and analyzed, the technical transformation parameters should be reasonably selected, and anti-abrasion measures should be taken. For a hydropower station with a lot of sediment passing through the machine, the turbine should be operated under the condition of no cavitation.
5.3.2 The technical transformation of the turbine shall be carried out in the following ways according to the specific conditions of the power station.
1 Use a new runner with excellent performance. The new runner should match the flow channel of the turbine. If necessary, the shape and structure of the flow parts should be improved through technical demonstration;
2.For small hydropower stations where the water head and flow have little change from the original design conditions, but the turbine equipment is outdated and the performance is backward, the performance of the turbine should be improved to increase the efficiency;
3 For small hydropower stations whose water head and flow rate are larger than the original design conditions, the rated water head and rated power should be increased;
4 For small hydropower stations whose water head and flow rate are reduced compared with the original design conditions, the rated water head and rated power shall be reduced;
5 For small hydropower stations with a lot of sediment, improve the hydraulic and structural design of the turbine according to the size of the passing sediment and the characteristics of the sediment, and use anti-abrasive materials and protective coatings. If necessary, reduce the speed of the turbine appropriately. less than 2 years;
6 When there are serious potential safety hazards or the damage reaches the scrap condition, scrap renewal should be carried out.
5.3.3 In the technical transformation design of the power station, the adjustment and guarantee parameters of the unit and the water delivery system shall be rechecked and calculated.
5.3.4 The technical transformation of thrust bearings shall meet the following requirements.
1.For thrust bearings where tile burning accidents often occur, the structural form should be improved or the cooling effect should be strengthened. For units with a rated speed below 750r/min, elastic metal-plastic thrust tiles should be used;
2 The unit capacity expansion design shall be rechecked and calculated for the maximum axial thrust of the unit, the bearing capacity of the thrust bearing and the bearing capacity of the foundation.
5.3.5 The radial bearing of the horizontal shaft can adopt rolling bearing or sliding bearing. Sliding bearings can use Babbitt alloy tiles or other suitable tiles, and water-cooled tile technology can be used if necessary.
5.3.6 The guide bearing of the vertical shaft turbine should adopt a parabolic non-scratch tile structure.
5.3.7 The technical transformation of the speed control system shall comply with the following regulations.
1.When the water head, flow rate, and diameter of the runner change, the characteristic parameters such as speed regulation power should be checked according to the turbine parameters;
2 The modified speed control system should meet the requirements of start-up and shutdown, fast grid connection, load increase and decrease, and emergency shutdown;
3 When the unit has a black start requirement, the governor should be equipped with a purely manual operation device.
5.3.8 It is advisable to use a microcomputer automatic speed governor or an operator with an energy storage device for the reconstruction of the speed control system. The governor can provide a pressure oil source for the automatic braking device when the operating work is satisfied.
5.3.9 The technical transformation of the water turbine inlet valve shall meet the following requirements.
1 When the water leakage exceeds the specified value of SL696 in the current industry standard "Basic Technical Conditions for Water Inlet Valves of Small Turbines", the sealing type of the water inlet valve should be improved or replaced with a new water inlet valve;
2 The valve should be equipped with a mechanical limit protection device;
3 The valve should be equipped with an automatic operating mechanism;
4 Valves operated by hydraulic pressure should be equipped with hydraulic devices with energy storage devices.
5.4 Auxiliary equipment
5.4.1 According to the requirements for technical transformation of unit equipment, the auxiliary equipment of hydraulic machinery shall be checked or modified accordingly.
5.4.2 The technical transformation of the water system shall meet the following requirements.
1 The transformation of the technical water supply system should meet the water demand of small hydropower stations after transformation;
2 For small hydropower stations with a unit capacity of more than 1000kW, the number of water intakes should not be less than 2;
3 For hydropower stations designed according to unattended (less manned), the technical water supply system should be equipped with automatic water filters, automatic control valves, and flow display signal devices;
4 The drainage pump of the seepage drainage system should adopt self-priming pump, submersible pump or deep well pump can also be used;
5 Pipelines that are severely corroded or whose pipe diameter does not meet the requirements should be replaced.
5.4.3 The technical transformation of the compressed air system shall meet the air demand of the unit after transformation. For power stations using governor oil pressure devices with bladder accumulators or hydraulic brake devices, the corresponding air supply system can be cancelled.
5.4.4 The technical transformation of the oil system shall meet the following requirements.
1.The turbine oil system shall simplify the pipeline laying, and the hose supply and discharge method should be adopted;
2 The oil depot of the insulating oil system should be canceled.
5.4.5 The unqualified lifting equipment should be modified or updated.
5.4.6 For the design of the power station for capacity expansion and transformation, the lifting equipment and its supporting structure in the factory shall be reviewed according to the lifting weight of the heaviest piece plus the weight of the spreader. When the lifting weight exceeds the rated lifting capacity of the crane, the crane and its supporting structure shall be updated or other safety measures shall be adopted.
5.5 Generators and other electrical equipment
5.5.1 The technical transformation of the generator should match the capacity of the turbine and other power transmission and transformation equipment.
5.5.2 The following methods can be adopted for generator technical transformation.
1 Replace the cooling system;
2 Replace the stator winding and rotor pole coil, the insulation level should not be lower than F level;
3 Transformation of generator bearings;
4 Update the generator.
5.5.3 Generators should be equipped with temperature detection elements.
5.5.4 Small-capacity high-voltage generators can be changed to low-voltage generators, and the modified generator capacity should not exceed 800kW.
5.5.5 For generators whose stator winding insulation resistance drops a lot after shutdown, a heating and dehumidification device can be installed. If the insulation resistance still does not meet the requirements after heating and dehumidification, the insulation should be replaced or other measures should be taken.
5.5.6 The technical transformation of the excitation system should adopt an excitation device with automatic adjustment function, and for units with isolated grid operation requirements, it should also comply with the current industry standard "Guidelines for the Design of Small Hydropower Units Operating in Isolated Grid" NB/T42034.The excitation system should adopt static excitation or brushless excitation.
5.5.7 The technical transformation of the main transformer shall comply with the following regulations.
1 The rated capacity of the main transformer should meet the needs of the output capacity of the transformed power station;
2 The main transformer with high energy consumption should be replaced with an energy-saving and low-consumption transformer;
3 Small hydropower stations with distribution transformers as main transformers should be updated with step-up transformers.
5.5.8 The technical transformation of other electrical equipment shall comply with the following regulations.
1 Electrical equipment should be selected as safe, energy-saving and environment-friendly products, and the use of equipment with high energy consumption and possible pollution to the environment is strictly prohibited;
2 The high-voltage circuit breaker should choose oil-free type;
3 The high-voltage switchgear should be selected to meet the "five preventions" (prevent mis-opening and closing the circuit breaker, prevent the load from opening and closing the disconnector, prevent the grounding wire from being hung up, prevent the grounding wire from closing, and prevent the operator from accidentally entering the interval) required light closed type;
4 Low-voltage switchgear should choose equipment that has passed 3C compulsory product certification;
5 Cables should be laid on cable racks or arranged through pipes.
5.5.9 The power station designed for unattended (few-attended) should be equipped with a reliable operating power supply. The operating power supply of the low-voltage unit with a stand-alone capacity below 800kW can use a UPS power supply that can meet the needs of switch tripping and electrical control.
5.5.10 The lightning protection grounding system should be improved to meet the grounding resistance design requirements.
5.5.11 The technical transformation of small hydropower stations should be equipped with emergency lighting. Lighting fixtures shall be configured as energy-saving and environment-friendly products and be easy to maintain.
5.6 Automation
5.6.1 The automation technical transformation of small hydropower stations shall comply with the relevant provisions of the current industry standard "Code for Automation Design of Small Hydropower Stations" SL229.
5.6.2 Small hydropower stations designed for unmanned duty (less people on duty) shall meet the following requirements.
1 A reliable digital protection device should be installed, and when the protection device operates, it should be able to stop the machine and send a remote signal;
2 It should have the functions of one-button start and stop, automatic frequency regulation, automatic voltage regulation and active and reactive power automatic adjustment;
3 It should have the function of remote control operation, and upload the operation information to the remote place or mobile communication equipment;
4 It is advisable to install a video surveillance system with automatic recording function;
5 An anti-theft alarm device should be installed.
5.6.3 It is advisable to install an automatic braking device for the technical transformation of the braking system of the unit.
5.6.4 A gate monitoring system should be installed for the technical transformation of small hydropower stations to realize remote control and monitoring. For fast gates, it should also have a one-button opening function.
5.6.5 The dam safety monitoring system and hydrological (condition) automatic measurement and reporting system should share data with the power station computer monitoring system.
5.6.6 For small hydropower stations using low-voltage units, the technological transformation of control equipment should adopt a simple and reliable digital monitor, protection, and excitation integrated screen.
5.6.7 The protection level of the electrical secondary screen cabinet shall not be lower than IP42 stipulated in the current national standard "Enclosure Protection Level (IP Code)" GB/T 4208, and lighting and dehumidification devices should be equipped in the cabinet.
5.6.8 The renovation of small hydropower stations should be equipped with communication equipment, and mobile communication equipment can be configured to monitor the operation of the power station and the water level of the reservoir.
5.6.9 The transformation of small hydropower stations can adopt the cluster control method of small hydropower stations. "Technical Transformation Standards for Small Hydropower Stations" GB/T 50700-2022
5.7 HVAC, fire protection and safety
5.7.1 Small hydropower stations with excessive temperature, humidity and noise should undergo technical transformation.
5.7.2 Fire-fighting technical transformation should be completed in accordance with the relevant provisions of the current national standard "Code for Design of Small Hydropower Stations" GB 50071, and complete various fire-fighting facilities.
5.7.3 Places that may endanger personal safety and the rotating parts of the unit should be provided with obvious safety warning signs and protective facilities.
5.7.4 For the switchgear room with a length greater than 7m and only one exit, a safety evacuation exit shall be added.
5.8 Ecological flow discharge facilities
5.8.1 For hydropower stations that cannot meet the ecological flow discharge requirements, the ecological flow discharge facilities should be renovated or newly built.
5.8.2 Renovation or new construction of ecological flow discharge facilities shall comply with the provisions of the current industry standard "Technical Guidelines for Dehydration Prevention and Control of Downstream Rivers of Small Hydropower Stations" SL/T796.
6 technical performance indicators
6.0.1 The unit power and unit efficiency after technical transformation of small hydropower stations shall meet the following requirements.
1 The output power of the unit should meet the design requirements for technical transformation.
2 The efficiency of the unit under the rated working condition should not be lower than that specified in Table 6.0.1, and the value shall be selected from high to low according to the power of a single unit.
Table 6.0.1 Unit efficiency range under rated conditions
3 The efficiency of the impulse hydroelectric generating set can be appropriately reduced.
6.0.2 The matching of mechanical and electrical equipment should be reasonable, and the equipment integrity rate of the technical transformation part should reach 100%.
6.0.3 After the technical transformation, the noise and vibration values of the turbine shall comply with the relevant provisions of the current national standard "Basic Technical Conditions for Small Hydro Turbines" GB/T 21718, and the noise and vibration values of the generator shall comply with the current national standard "Small Hydro Generators". The relevant provisions of the Basic Technical Conditions GB/T 27989, and the swing of the unit shall comply with the relevant provisions of the current national standard GB/T 8564 of the Technical Specifications for Installation of Hydroelectric Generating Sets.
6.0.4 The water leakage of the water turbine inlet valve after updating shall comply with the relevant provisions of the current industry standard "Basic Technical Conditions for Small Water Turbine Water Inlet Valves" SL696.
6.0.5 After the water guide vane is updated, the water leaking volume of fully closed water shall comply with the relevant provisions of the current national standard "Basic Technical Requirements for Small Water Turbines" GB/T 21718.
6.0.6 Turbine cavitation should comply with the current national standard "Evaluation of Cavitation Erosion of Water Turbine, Storage Pump and Pump Turbine Part 1.Cavitation Evaluation of Impact Turbine" GB/T 15469.1 or "Evaluation of Cavitation Erosion of Pelton Turbine" Relevant regulations of GB/T 19184.
7 project acceptance
7.0.1 The small hydropower station shall be inspected and accepted in time after the technical transformation is completed.
7.0.2 The technical transformation acceptance of small hydropower stations can be carried out in accordance with the relevant provisions of the current industry standard "Small Hydropower Station Construction Project Acceptance Regulations" SL168.
7.0.3 For small hydropower stations with partial technical transformation, the period of trial production and operation may be appropriately shortened, and the acceptance procedures shall be simplified.
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