Types, Advantages And Disadvantages Of Tubular Turbine Generators
Author: source: date: 2020-06-12 10:37:45
Everyone knows that hydropower uses rivers, lakes, and other high-potential energy flows to low places, and converts the potential energy contained in it into kinetic energy of the turbine, and then uses the turbine as the power to promote the generator to generate electrical energy. That is to use the hydraulic power to push the hydraulic machinery to rotate, transform the water energy into mechanical energy, and then connect another type of generator to the turbine, which can generate electricity as the turbine rotates. The hydraulic machinery in the middle is the turbine. Introduce the tubular turbine today.
Tubular turbine is a horizontal shaft turbine, that is, the water flow basically moves along the horizontal axis in the flow channel. It is mainly applicable to the water head of 1～25m, and it is a special type of low-head, large-flow hydropower station.
1. Bulb Tubular Turbine
Bulb Tubular Turbine is a complete hydro-generator set produced by the factory. The generator is connected to the hub part of the hydraulic turbine and is shaped like a light bulb, so it is commonly known as a bulb flow type. The bulb body can be placed in the inlet pipe or in the open tank. There are two forms of connection between bulb tubular units, one is direct connection and the other is indirect connection. The direct connection structure is simple and easy to manufacture, but the turbine must have a high speed, so it can only be used in power plants with certain hydraulic conditions. When the power head of the power station is low and the flow is large, the speed of the turbine is much lower than the speed of the generator, and an indirect connection must be used. Indirect connection generally connects the turbine shaft and the generator shaft through a gear speed-increasing system. The structure is relatively complicated, but the scope of use of the turbine is large.
For example, a certain type of water turbine, in the sealed bulb body, it has a speed-increasing system called planetary gear, which connects the turbine shaft with a speed of 357 rpm and the generator shaft with a speed of 1000 rpm to rotate together. The unit is installed on a hydropower station built with industrial wastewater. The unit has a design head of 2.0 meters and a design flow rate of 1.4 cubic meters per second. It can be found that its structure is indeed relatively simple. The efficiency of the bulb tubular turbine generator set is high, the hydraulic structure of the hydropower station is very simple, the construction and installation are very convenient, the practice proves that the underwater operation performance is also good, and the main part of the hydropower station is underwater, which meets the production requirements . However, the structure of the indirect transmission unit is complicated and difficult to manufacture. In addition, the sealing, moisture-proof and maintenance of the generator are also troublesome, which is its main disadvantage.
2. Shaft extension flow turbine
The common features of shaft extension type, shaft type and gear box type are that they still maintain the basic structure of the cross flow type. The generator is arranged on the water part of the plant and is indirectly driven by belts or gears. Compared with the bulb-through type, this type of turbine is simple in structure and easy to manufacture, and the problems of ventilation, cooling, moisture resistance and maintenance of the generator are easy to solve, which is their common advantage. The shaft of the shaft-extended turbine must pass through a bent pipe (inlet pipe or draft pipe), which is connected to the generator outside the pipe. The shaft is relatively long, and the flow path is bent. The rotating main shaft will deteriorate the flow of the water flow, so the efficiency Slightly reduced, this is a disadvantage.
3. Shaft Tubular Turbine
The characteristic of vertical shaft turbine is that the generator or transmission belt is arranged in the concrete shaft. If the shaft is located in front of the turbine, it is called a front shaft, and the water flow is divided into two streams from the outer wall of the shaft and enters the runner. If the shaft is located behind the turbine, it is called the rear shaft, and the water flow is divided into two streams and enters the draft tube. Obviously, the hydraulic loss is larger than that of the bulb-through type, but the structure is firm, not easy to vibrate, the turbine shaft is short, and the operation is smooth.
4.Gear box tubular turbine
The characteristic of the gearbox tubular turbine is that a pair of bevel gears are used to transmit power. The bevel gears are installed in the gearbox, which is very similar to the bulb type in appearance. The flow path of this turbine is unobstructed, and the hydraulic loss is small, but the bevel gear manufacturing and processing are more difficult.
Tubular turbines because the water flow basically moves along the axial direction in its flow channel and does not turn, so the water passing capacity and hydraulic efficiency of the unit can be improved. It is especially suitable for tidal power plants. In recent years, due to the fact that tubular turbines are suitable for low head applications and have low investment and high