Description: |
In the first part of the lecture, students are introduced to the application of steam turbines in energy conversion systems. This includes the conversion of sunlight into electricity through Concentrated Solar Power, utilization of waste heat with the Organic Rankine Cycle, use of radial expanders in fuel cell systems and energy storage by means of Carnot batteries. Furthermore, different system designs (condensation, back-pressure, extraction, saturated steam, supercritical) are explained.
The evaluation of the steam turbine and the overall process via different efficiency definitions and exergetic analysis is also a part of the lecture, as are possible process improvements (live steam temperature and pressure, regenerative feedwater preheating, intermediate superheating). Subsequently, the use of the Rankine cycle as a bottoming process is explained. The consideration of the overall system finally leads to the definition of requirements for the design of the steam turbine. Stage characteristics, low-pressure stages, wet steam problems, axial and radial design are explained. The one-dimensional design of steam turbine stages and characteristics of the blades are also part of the course, as well as three-dimensional flows. For this purpose, solution approaches for the conservation equations are introduced, and profile, boundary and gap losses, and secondary flows are discussed. Afterwards, various design aspects are introduced (drum design, axial thrust and thrust balancing, turbine rotor, rotor blades, guide vanes, guide vane carriers, turbine casing, shaft seals, casing and rotor expansion). The lecture concludes with the control and operating behaviour of steam turbines. |