My original response, not copied online.
The process of building hydroelectric power stations cannot be explained clearly in one or two sentences.
Generally speaking, it is divided into project establishment, design and implementation. The implementation phase is divided into preliminary preparation, formal construction, completion reception and operation. It is estimated that the poster wants to ask questions about the process of the implementation phase, and this will be the subject below.
Project approval:
Whether or not to build this power plant is not a matter of whim. It can be built anywhere.
First of all, it is necessary to calculate the water energy of the pond to see if there is water energy to produce electricity.
Then it is necessary to plan the entire river basin, determining in which sections power plants can be builtand how many power plants can be built.
Next, make a preliminary understanding of the geological and hydrological conditions and make preliminary estimates of inputs and outputs. Some people only start this project if they make money.
Design:
Once the project is approved, geological exploration, engineering design and cost estimation are required. During this period, it must go through several stages of feasibility design, tender design and technical installation design. I won't go into details. Design drawings for this power plant have finally been released.
Implementation:
After the tender design drawings are published, the construction unit can be selected. Large projects are usually divided into several bidding sections to select different unitsconstruction works.
After finding the construction unit, construction can begin.
The first is made up of three connections and a single level: roads, water, electricity, and the site is flat. That is to say preparation work, without which subsequent construction cannot take place.
Then there is the construction of the diversion project. Large-scale projects typically require cutting the river, building cofferdams on the upstream and downstream sides of the dam foundations, and digging another hole or channel to guide. the water in the river is falling (otherwise during the construction period the water in the river has nowhere to go).
Then came the construction of dams and factories. It's more complicated. There are many types of dams and plants, and the methods and processes are different. Generally speaking, the foundations are treated first, the floating soil is excavated, the stones aret exposed, concrete is poured and the dam and factory building are poured.
At the bottom are the metal structure and the mechanical and electrical installation, which is the welded steel sheet tube mentioned by the poster. However, generally large-scale projects involve very large metal structures, such as arch gates, flat plate gates, turbines, volutes, pressure steel pipes, etc., which are much more difficult than steel plates. They are first spliced in the factory and then transported to the dam and factory for hoisting.
After installation, you can store water. After water storage, trial operation and acceptance of completion, power generation can start.
Liuhong Hydropower Station is the fifth-level power station developed in the main stream of the Meigu River. This is a power planthigh head diversion. Three Francis turbine generator sets are installed at the plant, with a total installed capacity of 180 MW. The diameter of the volute inlet section is 1.3m, the material of the volute is 16Mn, and the thickness is about 38mm. Although the volute of the power plant is not large, it is subject to high internal water pressure. As one of the important components of the hydrogenerator unit, the volute and the reinforced concrete structure around it face many new technical problems, such as. such as the use of bottom-mounted water turbines, maintenance methods, etc. Therefore, how to design the volute structure is related to whether the power plant can operate stably and safely in the long term. After technical analogies and taking into account the stable operation requirements of the unit, the volute of Liuhong Hydropower Stationdecided to adopt the structural type of water-filled and pressure-maintaining concrete. In order to optimize the pressure maintaining value of the volute and the reinforcement of the concrete peripheral structure, this paper mainly conducts research on the following contents: (1) Research on the types of volutes of domestic engineering turbines and foreign, especially the casting process. concrete volutes using water filling and pressure, pressure values, costs, construction progress and other technical and economic conditions were studied and analyzed to provide a basis for structural design of the volute of Liuhong Hydropower Station (2) optimize the pressure filled with water; holding value of the volute, using the three-dimensional finite element method Calculate the volute and peripheral concrete, carry out a comprehensive comparison of the unit operating performance, de the stress state of the peripheral concrete, deformation rules and configuration of the steel bars, and finally optimize the filling and water pressurization value.