1, the diversion system information
Plant water reservoir system is located between the mountains and down the body, using a hole two machines, inclined shaft, tail plant layout program, there are two identical hydraulic unit. Water Conveyance System main buildings include: the upper reservoir inlet / outlet, diversion tunnel, reinforced concrete manifold, high pressure steel pipes, tailrace tunnel and the lower reservoir inlet / outlet and so on.
Upper reservoir inlet / outlet is located in the cove from the left Batou about 500m, using the slope shaft-style layout, flow into the intake side, the same two intakes arranged by beams and vortex diffuser composed of a single length 100m, width vortex beams 40m, high 30m, bottom elevation 400m, imports from four trash rack. Between the diffuser and the gate well as the 10m × 13m (width × height) of the rectangular opening paragraph, emergency gate spacing imports 120m, gate size 10.0m × 12m (width × height). Intake open channel segments depending on the terrain in front of the plane with curved layout, length 450m, width 90m ~ 150m, bottom elevation of 400m ~ 420m, 80m imports from Nullah frontier and stopped at the sand ridge located prescribe.
Center spacing of the two diversion tunnel 80m, Diameter 12m, the hole axis azimuth of N87 ° E. On the flat segment fell to 15% elevation 400m down the slope, then dip 60 °, 500m long high-pressure inclined, down to 100m elevation, the lower flat section is connected to the high voltage, respectively, after the 200m and 290m horizontal section of the bifurcation of four high-pressure manifolds. From the reservoir inlet / outlet to the fork tubes are reinforced concrete lining structure, high pressure manifolds after the bifurcation of the use of steel lining, the 1st to the 2nd long steel-lined high pressure manifolds respectively 170m, 190m, 200m, 210m, diameter 8m ~ 5m, high pressure manifolds axis azimuth of N65 ° E. From the reservoir inlet / outlet to the length of the 1st to the 2nd unit high pressure manifolds steel liner ends aqueduct were 900m, 980m, 1070m, 1100m.
2, high-pressure steel pipe structure
Surrounding rock granite high pressure pipe segment to Class Ⅱ surrounding rock based. A total of four high-pressure steel pipe, steel pipe inner diameter of 8m ~ 5m, for easy maintenance and drainage, steel tapered section with flat layout, pipe centerline elevation 80m ~ 60m. No.1 to 4 units high pressure pipe centerline distance from the starting position for the 256 ~ 300m. In the 200m at the inner diameter upstream from the plant by 8m tapered sidewall to 5m, with the ball (D = 4m) are connected. To prevent high-pressure steel pipe seepage destabilizing, in the steel pipe section to set the initial four sealing ring, high 700px. Steel factory settings before entering three thrust ring, to mitigate the effects of a huge ball valve is closed when the axial thrust of the steel pipe. To increase the resistance to external pressure steel pipe and tube sections stiffness capability, each section steel pipe generally set two stiffening ring stiffener ring high 780px, thickness and material of the same pipe.
Engineering design of the pre-bid, high-pressure steel pipe conveyance system design is based on the internal pressure of hydraulic transition process is based on the calculation results calculated 600m. To tender later in the design, according to the Hadza corporate advisory report, the design uses design head internal pressure based on the total head 500m plus 50% of the water hammer pressure after 700m (ie 70MPa) is calculated as the inner pressure, compared with a 15 percent increase the previous calculation . Therefore, the design of the plate thickness were calculated in the previous review. According to "hydropower penstock design specifications" (SD144-85), through the high-pressure steel pipe according to Ming tube (plant upstream 20m), the half-pipe (16 ~ 121m plant upstream segment) and pipe (upstream section of the plant other than 60m) respectively Checking of internal stress that the tender design uses 32MnR and 8MnCrMo steel fully able to meet the design requirements.
After entering the technical construction design stage, consider ordering steel case, recalculated according to the latest promulgated "hydropower penstock design specifications" (DL / T5141-2001) but also on the high-pressure steel pipe sheet thickness, the results are as follows:
