We extend CEEN by professional knowledge transfer between Europe and China in the area of the energy sector. In the following weeks CEEN will therefore feature several tutorials covering topics such as power plant technologies and electricity and gas trading. We start with a series of 24 parts on power plant technologies.
During the coming ten weeks we will examine power generation in thermal power plants. Then, a seven weeks series on electricity generation in nuclear power plants will follow. Finally, the tutorial on power plant technologies will come to an end with a seven weeks series on renewable power generators.
The first 10 weeks of this tutorial will deal with the principles of today’s biggest power plants. Efficiency, fuel technology and flue gas treatment, along with power plants based on gas turbines and combined heat and power technology are explained in this first part of the tutorial.
The topic of the first week:
1. Power generation in thermal power plants
The development of power generation started with rather small units. Development over time did however lead to ever bigger power plants, as cost degression could only be realized with increasing generation capacities. Gains in efficiency were thus possible.
The general steam power process
The generation of electricity requires energy, which is available in form of primary energy carriers. Primary energy carries can however not be “directly” transformed into electricity. In order to tap the energy which is stored in primary energy carriers, technical processes are necessary.
Chemically contained energy can be released via combustion, while nuclear fission relies on a different process. Even though we talk about a “fuel assembly” here, no actual combustion process is taking place. Instead energy is released in form of fast neutrons.
A fuel cell allows for direct transformation of chemical into electrical energy, the number of available energy carriers is however quite limited.
When burning energy carriers the foremost product is heat. A common process to transform this heat into electricity is the so called steam power process. The process requires a closed system, where water is the medium and does not leave the system. Water is well suited due to its large availability, its high heat capacity and its high thermal conductivity. Furthermore, it has a low boiling point.
During the steam power process the medium passes through four changes of state, while it takes up or releases either thermal energy (Q) or work (W). A change of state in this case means that either pressure or temperature (or both) of the working medium, here water, change.
A simplified thermal process consists of four components and the pipes connecting those:
- Steam generator and superheater
- Turbine and generator
- Condenser
- Pump
