1985 The local power company of the province, Quanzhou, Yongchun and Dehua counties set up Longmentan Water Diversion Project Development Company in Quanzhou, Fujian, to jointly invest and develop. The first-phase tunnel and the first-phase Shangfeng Power Station started construction in the same year. The diversion tunnel of Longmentan I Hydropower Station is 2,872 meters long, with an excavation diameter of 4.6 meters, a lining diameter of 4.0 meters and a design flow of 27.66 cubic meters per second. The first-class power station is equipped with two hydro-generator sets with a single unit capacity of 9000 kW produced by Fujian Hydropower Equipment Factory, with a total installed capacity of10.8 million kW and an average annual power generation of 76 million kWh. 1990, generating 44.02 million kwh. In 2000, the added capacity was 2× 1600kw.
The first-stage power station of Longmentan Reservoir was started on February 26th 1985, and the dam was stopped to store water on August 27th 1989. On September 6 of the same year, the first unit was officially generated. The second unit generated electricity on 65438+February 1 day in the same year. 680,000 cubic meters of earth and stone were completed, with an investment of 57.75 million yuan (including 3.5 million yuan for 1 10 kV line and preliminary works of secondary power station). In addition to raising funds from provinces, cities and counties, the former Ministry of Water and Electricity and the Ministry of Energy also provided low-interest loans of 20 million yuan for the project construction. Longmentan secondary hydropower station is a secondary hydropower station in the cross-basin water diversion project of Longmentan. Longmentan Water Diversion Project is located in Dehua County, Fujian Province, across Minjiang River and Jinjiang River. The dam was built to store water in Longmentan Canyon, which is a river in the upper reaches of Dazhangxi. Through a 3.0km long tunnel crossing the river basin, water is introduced into Jinxi River in the upper reaches of Dongxia Lake and Yangxi River in Jinjiang, realizing inter-basin water transfer and comprehensive utilization of power generation, irrigation and water supply. The installed capacity of the first-class power station is 18MW, and the second-class power station will build a low dam in the Jinxi River Basin about 500m downstream of the first-class power station, forming a reverse regulation reservoir with a total storage capacity of 700,000 cubic meters. Water will be transported to the ground power station through a 3.45-kilometer-long tunnel and pressure pipeline. The design head of the power station is 1 10m, the diversion flow is 30.9m3/s, and two units are installed.
The control basin area of the secondary power station reservoir is only 1 1.8 square kilometers, and the inflow is mainly the inter-basin water transfer of the primary power station, with the total annual runoff of 424 million cubic meters (including inter-basin water transfer of 4 1 1 100 million cubic meters). The annual average flow 13.44 m3/s (in which the first-class power station corresponds to the power generation flow 13.02 m3/s), the normal water level of the reservoir is 360.0m, the dead water level is 356.0m, and the total storage capacity is 700,000m3, of which the regulating storage capacity is 410.5000m3, which is a daily regulating reservoir. The secondary power station project hub is mainly composed of barrage, exposed pipe behind dam, diversion tunnel, surge chamber, pressure pipeline, ground powerhouse and booster switch station.
The maximum reference flow of the secondary power station of the diversion system is 30.9 m3/s (two units). The diversion system consists of exposed pipe behind the dam, diversion tunnel, surge chamber and pressure pipeline. The exposed pipe behind the dam has an inner diameter of 4.2m, a length of 3 1.5m and a design wall thickness of 500mm. In order to reduce the pipeline cracks caused by temperature stress, a new type of external masonry composite structure is designed. The total length of diversion tunnel is 3159.5m, the designed excavation diameter is 4.8m, the inner diameter of reinforced concrete lining section is 4.2m, and the inner diameter of sprayed concrete lining section is 4.56m ... The surge tank is an internal double-tube differential structure with an inner diameter of 8.5m and a wall thickness of 500mm. The riser has an inner diameter of 2.5m and a wall thickness of 400mm；; The total height of surge chamber is 37.078m, and the pressure pipeline consists of upper horizontal tunnel section, inclined tunnel section, lower horizontal tunnel section and power generation branch pipe. The upper section of the tunnel is 57.0 m long, the inner diameter after lining is 4.2 m, the thickness of reinforced concrete lining is 500mm, the length of inclined lane 1565438+500mm, the slope of inclined lane is 35, the inner diameter after lining is 4.2m, the inner diameter after lining is 23.0m, the inner diameter after lining is 3.2m, and the length of steel plate lining is128.0m.: The inner diameter of steel plate lining in the lower tunnel section is 3.2m, the length of main pipe is 6 1.0m, the length of bifurcated pipe is 9.0m, the length of two power generation branch pipes is 8.0m, and the inner diameter of branch pipes is1.75m. Longmentan IV Hydropower Station is a hybrid power station, located in Huyangxi reach of Dongping Town, Yongchun County. The catchment area of rainwater in this basin is 3 14 square kilometers, and the inter-basin water transfer is 360 square kilometers. The average runoff above the dam site is 735 million cubic meters, the installed capacity of the power station is 28,000 kWh, the total storage capacity of the reservoir is 6.5438+0.625 million cubic meters, the design head is 5 1 m, the design flow is 64.8 cubic meters per second, and the average power generation for many years is 94.29 million kWh. The hydropower station started in June 2003 with an investment of 259 million yuan.
The normal water level of the reservoir in the first phase project is 158.5 m, the corresponding storage capacity is15.33 million cubic meters, the total storage capacity is16.25 million cubic meters, and the reservoir area is 1.23 square kilometers. The installed capacity of the power station is 28MW, the guaranteed output is 3.984MW, the average annual power generation for many years is 94.29 million KW·h, and the estimated total investment of the project is182.05 million yuan. The project scale is medium, and the project grade is third-class. The total amount of earthwork excavation is 6.5438+0.25 million cubic meters, and the amount of waste slag is 90,000 cubic meters. The construction period is 2 years and 6 months. The main transformer of the step-up transformer has a capacity of 40000 KVA, and the voltage level is10/10 kv. Generator-main transformer expansion device is used for wiring. 1 10KV line is connected to 1 10KV shanchun t line, which is transmitted to the power grid through Shan Mei hydropower station 1 10KV mountain view line. The first phase of the project also includes 1 10 kV transmission line, which runs from Longmentan secondary power station to Dehua Chengguan Substation 16.7 km through the primary power station. The project was completed in August 1989. The first-stage power station was completed in September, 1989. The construction of the secondary power station started in July 1989.
The commander-in-chief of Longmentan Water Diversion and Power Generation Project is Chen and Qiu Shuangjiong. Technical design includes Provincial Hydropower Design Institute, Quanzhou Water Conservancy and Hydropower Bureau and Dehua County Water Conservancy and Power Bureau; Longmentan Development Company is responsible for the construction in cooperation with the Provincial Hydropower Engineering Bureau.