What are large-scale electrical generator turbines and bulb-type generators?
The bulb turbine is a type of hydroelectric turbine designed for use in low-head waterfalls, typically below 20 meters. Its distinctive feature is its bulbous shape, a sealed capsule that encloses both the turbine and the generator.
This turbine is based on the design of the Kaplan turbine, which is a hydraulic axial flow turbine with adjustable blades. By harnessing the kinetic energy and pressure of moving water, the bulb turbine generates mechanical energy, which is converted into electrical energy by the generator coupled to its shaft.
One of the advantages of the bulb turbine is that it can operate completely submerged in the water flow, eliminating the need for a separate containment structure, as is the case with other hydroelectric turbines. The sealed capsule houses the turbine-generator assembly, ensuring its operation underwater.
How does the cooling of the bulb turbine work?
Cooling the bulb turbine is an important aspect. Due to immersion in water, the heat generated during operation is dissipated by the water flow around the turbine itself. Additionally, to aid in cooling, high-speed, small-diameter fan jets are used. These jets direct air into the turbine capsule, promoting circulation and cooling of the internal environment.
With experience in serving Voith, we have customized equipment for this application within our TJF product line.