Analysis of post-disaster reconstruction Yushu repair and reinforcement of small hydropower and management measures

[Abstract] at 7:49 on April 14, 2010, Qinghai Province, Yushu County, Yushu Tibetan Autonomous Prefecture earthquake of magnitude 7.1 occurred, sudden disaster of Yushu people's lives and property caused huge losses. Earthquake in more than 2 200 victims, do lives were injured, do houses collapsed, never head of livestock ... ... so little weak in Yushu Prefecture had also been an unprecedented water damage, the existing 22 small hydropower in total 19 different levels of seismic were destroyed, earthquake damage, which the West Hangzhou, contemporary earthquake destroyed two hydropower plants, total installed capacity of power plant damaged 26.85 MW, causing direct economic losses of 160 million for the full economic benefits of these power plants built for the problems, through post-disaster reconstruction, repair and reinforcement to increase efficiency and strengthen the management of great possibility.

[Keywords] reconstruction; small hydropower; repair and reinforcement; management measures

1 Overview jurisdiction over Yushu Yushu area, more complex, Nangqian, said more qumarleb, rule six more counties, a total area of ​​26.4 × 104 km2, total population of 35.73 million, of which urban population of 5.1 million people. Within the water resources are very rich theoretical potential of 5 427 MW. 6 counties in the state, as the capsule modest heteropoly Lancang River counties, said more government and more, Yushu, qumarleb 4 counties are mainly the Yangtze River. These water resources due to traffic, financial difficulties and other factors, the use of the low level of the earthquake before the state a total of 22 small hydropower stations, are small (Ⅱ)-type, with a total installed capacity of 28.4 MW, the total reserves of 3.3 ‰, including the reservoir power station 4 Block, are small (Ⅰ) reservoir, with a total capacity of 1 632 × 104 m3, the task for the power generation, irrigation and water supply is not required .22 hydroelectric power stations in the aging equipment, some serious, affecting the normal power generation operation.

2 Before the earthquake the problems of small hydropower in Yushu

Yushu area, some of the early construction of small hydropower as lack of hydrological data, planning and design is not reasonable, part of the improper selection of station electrical and mechanical equipment, or adjust the performance is poor, abandoned more than water; or the use of fewer hours, more than idle capacity, and electrical equipment and hydraulic serious aging facility itself is also a declining trend in efficiency of these small hydropower stations through decades of operation, and accumulated a lot of valuable information on aspects of running the repair, but due to personnel changes, and many other reasons, many drawings (design and equipment) incomplete incomplete, and even the nameplate on the unit have been lost, so the reconstruction reinforcement and repair of the original design (including hydrology, engineering design, equipment and plant operation maintenance records, etc.) to collect, analyze and summarize very difficult specific problems in: (1) turbine performance, backward, obsolete technology, poor manufacturing quality, defects, repair long unhealed, long-term sick to run, contribute to inadequate security and poor reliability.

(2) turbine and electrical equipment is not complete. Some of the turbine generator or power output greater than the rated capacity of the main transformer, the design of the hydropower output is limited, generating abnormal abandoned when the water phenomenon. And some generating capacity in the turbine output, a waste of the equipment capacity, but also increases run loss.

(3) hydraulic structures fell into disrepair, especially the water damaged severely hub and canal building, abandoned water more. Water flows meet design requirements, the unit can not operate at full capacity. In addition, because the Yushu area of ​​small hydro Most of the open channel diversion type power stations, running in winter difficult, if not run.

Therefore, these small hydropower stations during the post-disaster reconstruction repair and reinforcement design, you must find out what problems exist, including the actual operation of the head, to water, discard water, electrical and mechanical equipment condition, hydraulic structures and metal structures operating conditions, etc. Only to find out the problem completely, in order to formulate and carry out maintenance and reinforcement design, in order to achieve the intended purpose of post-disaster reconstruction.

3 Yushu area of ​​earthquake damage of small hydropower

Yushu earthquake that had weak local small hydropower has been the unprecedented destruction of the existing 22 small hydropower in the total of 19 different levels of earthquake destroyed by the earthquake damage, which the West Hangzhou, contemporary two hydroelectric earthquake destroyed, damaged power plant The total installed capacity of 26.85 MW. major damage to the building of a dam, spillway 12 buildings, 12 water diversion structures, plant and tail water 14 buildings, four production and living facilities, 15 step-up station. Ancient Zen earthquake severely damaged the dam and sluice, can not function properly, which caused direct economic losses of 160 million yuan.

4 Yushu small hydropower in the principles of post-disaster reconstruction, based on the emergency repair repair earthquake damage to the station for restoration and reconstruction of the extremely serious damage to the appropriate scale hydropower stations to improve the standard redevelopment or re-siting a new, appropriate technological transformation a new or hydropower station approved for post-disaster reconstruction and Yushu Yushu economic and social development to provide electricity. <<Yushu earthquake recovery and reconstruction master plan>> as soon as possible in the repair Lagoon, ancient Zen and other 11 hydropower stations damaged, rebuild Western Hangzhou, contemporary 2 hydropower stations, the new Long-pass check, check on button station.

5 Yushu post-disaster reconstruction of small hydropower modification measures 5.1 to optimize the design, to maximize the economic benefits of post-disaster reconstruction of small hydro power station design should address the loss of hydraulic structures and the original equipment shock of aging, optimize design closely and properly handle the power plant can not be changed or not changed constraints, limited investment in the case, try to increase the annual power output, improve the economic benefits of hydropower.

5.2 use of limited resources, re-construction site in the Yushu earthquake, earthquake damage is the most serious contemporary West Hang hydropower station and the West and contemporary Hang hydropower hydropower intake, flushing sluice, spillway, diversion canal , forebay, plant, tail water, housing and living areas are damaged equipment, pressure pipe, booster station, road and equipment was severely damaged, together with the original West Hang hydropower diversion canal on the far right side of State Road 214 on the stability of the mountain, to State Road 214 is a big threat these two hydropower stations were built in the town of Yushu Results town area, West Hang hydropower station tailrace of aqueducts and contemporary through the residential areas are Some residents of the housing built in the channel on the edge of frequent house underground seepage events.

After many discussions, the experts, in-situ construction is highly unlikely, and only re-location of new construction, in order to compensate for the electricity shortfall caused by the earthquake. Heavy earthquake damage can not be said to run more than one, break arms, such as Jiang Rong hydropower are developed early, run a longer life, water is too simple hub, silt intake have been basically flat, forebay and plant dilapidated, severely damaged canal structures, hydro-generating unit on the verge of obsolescence, main transformer capacity can not meet the power requirements, operating costs than power generation, if reconstruction or reinforcement of maintenance, estimated investment of 500 million, a large investment in rehabilitation and reconstruction after the two power plants of total installed capacity of 700 kW, or can not effectively solve the electricity supply and demand through economic analysis and comparison, it should be re-siting New.

5.3 to increase the storage capacity, improve the ratio of the Yushu area peak electric power enterprise is not large, mostly farmers and herdsmen's living power, the next day in the evening 18 points to zero for the peak period, while the majority of local runoff is the water diversion power stations, daily regulation is poor, so the terrain and location suitable to allow the power station, in the reconstruction, repair and reinforcement of the process should be used to expand capacity or build more water storage pool before the point of approach to improve storage capacity, multiple peak power, thus increasing the economic efficiency of power plants.

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5.4 channels and water maintenance hub, reduce the drop of water in the Yushu earthquake, earthquake damage is more serious Qumalai hydropower station, built in Colmar station are the old 1960s and 1970s station, was originally limited to design and construction techniques, irrigation channels and generally poor quality of water hub, a serious threat to the safety of power plants coupled with the earthquake, so that the two hydropower aqueduct total destruction, and therefore the hub of demolition and reconstruction of water diversion channels and repair or reinforcement, reduce the drop of water, increase runoff efficiency, increase the economic benefits of small hydropower stations.

5.5 insulation measures taken to increase power generation in winter the climate is only heating the Yushu area of ​​difference, no four seasons, the annual cold season 7 to 8 months, 4 to 5 months of the warm season, there is no absolute frost-free period, the weather is cold and wet and dry unevenly The annual average temperature of -0.8 ℃, annual minimum temperature of -42 ℃, the maximum temperature of 28 ℃, the average annual rainfall 463.7 mm, oxygen content lower oxygen content than sea level 1 / 3 to 1 / 2 severe weather and more snow, early frost, cold, drought, hail and other natural disasters, seriously restricting the operation of small hydropower in winter, so insulation measures to be taken to increase winter power generation in the reconstruction process for the pressure pipe should be used in buried-type (larger than the maximum permafrost), stamped Cattle approaches to the use of antifreeze or load rejection after midnight when I power on the pressure tube electric heating for channel transformation, set culverts, covered antifreeze for intake and the duty to strengthen the front room visits, and remove ice, give full play to the role of exclusive ice gate.

6 post-disaster restoration and reconstruction measures for the management of small hydropower 6.1 strengthen management, improve efficiency in addition to engineering and technical measures to improve the economic benefits of small hydropower stations, but also benefits to management, technology management for small hydropower production of all technical and scientific activities management and close-knit organization, so that science and technology into productive forces, thereby enhancing economic efficiency, improve effectiveness of the protection is safety, safety is the core of management, the result is efficient management. small hydropower stations are small, unit capacity is small, fewer personnel. a lot personnel who are also electrical, mechanical and operations, maintenance personnel who are also electrical, mechanical overhaul two jobs, and some stations did not even plant maintenance workers, equipment maintenance personnel when deployed to run out and participate in repair. With the development of science and technology, many small hydropower stations has been widely applied

Advanced equipment and technology, lack of knowledge of existing staff, find it hard at work, so as to improve the economic benefits of small hydropower, focusing on the power plants (mostly water-power station) operating business training, efforts to improve operating the technical and professional quality, so that they can run continuously improve operations, identify problems and problem-solving skills, to ensure that power plants can be efficient, reliable operation, improve the economic efficiency of power plants.

6.2 to build the whole system in place

Establish and improve the system, strengthen the technical management of the operational status of equipment, maintenance and accident or malfunction of statistical analysis will help to take targeted measures to improve equipment utilization, reduce equipment failure rate, play a revenue and cut expenditure role hydropower plant equipment maintenance, the team should be strictly applied, plant, power plants and a combination of self and mutual inspection of the three inspection systems, maintenance and repair of small hydropower stations must follow the principle of prevention, and effectively "should compulsory repair, maintenance mandatory good ", not to be" recklessly, their teeth. "professionals in the technical file shall be responsible for the management to ensure data integrity, system, accuracy of small hydropower stations should be established factory, workshop, three technical management of network, responsible for managing the different levels of responsibility to the people.

6.3 Optimal efficiency

Reconstruction of small hydropower stations in operation should correctly handle Feng Ku, peak and valley relations, the implementation of optimal scheduling. Hydrological stations upstream of timely and accurate understanding of the hydrological forecast information, and discharged under the regulating capacity of upstream water flows on to the analysis, we are preparing the next day load projections to determine the operating mode. the rational use of effective capacity of power plants to maximize the upstream water level, make full use of water resources, maximize the benefit of power generation plant. a combination of unit operation mode, according to the high efficiency, low water consumption the principle of priority, to ensure unit to run efficiently in order to obtain maximum economic benefit.

[References]

[1] Department of Water Resources of Qinghai Province Qinghai Yushu earthquake recovery and reconstruction of water conservancy special plan [R]. Xining: Qinghai Department of Water Resources, 2010.

[2] Ethan Chang. Yushu in Qinghai Province disaster reconstruction of small hydropower maintenance program [R]. Xining: Qinghai Yushu Power Company, 2011.

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