Adding combined cycle power plant (CCGT)

[Alex2448]

Description of the issue

Currently, we have different types of power plants, but we do not have a combined cycle power plant. Since we have gas power plant, steam, steam turbine and gas turbine already defined, I think adding combined cycle power plant (and therefore also steam power unit) is a nice complement to the existing terms.

Ideas of solution

• A steam power unit is a power generating unit that uses steam energy.
• A combined cycle power plant (CCGT) is a gas power plant that has gas fired power units and steam power units as parts.

Workflow checklist

• I discussed the issue with someone else than me before working on a solution
• I already read the latest version of the workflow for this repository
• The goal of this ontology is clear to me

I am aware that

• every entry in the ontology should have a definition
• classes should arise from concepts rather than from words

[l-emele]

In my view, your definition proposal excludes single shaft CCGTs. In those, the gas turbine, the heat recovery steam generator, the steam turbine and the generator form one unit.

Maybe, it is helpful, to define the CCGT process first and then the actual units / power plants.

[Alex2448]

@l-emele what do you mean with define the CCGT process first? For example gas power plant just participates in some energy transformation and has part some power generating unit and no specific process.
I think introducing also heat recovery steam generator is quite easy:

• heat recovery steam generator with the parent class energy converting component:

  • A heat recovery steam generator is an energy converting component that recovers heat from a hot gas stream and produces steam with a lower temperature.
    

Then, we can use the heat recovery steam generator with the axiom has part for the definition of CCGT.

[l-emele]

@l-emele what do you mean with define the CCGT process first?

Something like: Combined cycle electricity generation is a fuel-powered electricity generation process in which a gas turbine process is followed by an steam-electric process.

[l-emele]

I think introducing also heat recovery steam generator is quite easy:

* `heat recovery steam generator` with the parent class  **energy converting component**:
  
  * ```
    A heat recovery steam generator is an energy converting component that recovers heat from a hot gas stream 
    ```

Isn't that a special kind of a heat exchanger? Then it would be better to define: A heat recovery steam generator is a heat exchanger component that recovers heat from a hot gas stream.