During this first step, you will seek:

• to acquire all the basic concepts

• to master the tools that will allow you to increase your knowledge

• to understand the basic examples (gas turbine, steam power plant, refrigerator)

The methodological approach is presented in session S01En Introduction, educational approach .

As mentioned in the introduction of the course, we think pedagogically preferable to minimize the use of equations as long as your culture in applied thermodynamics is limited. We will therefore only present equations in the Diapason modules when they are simple enough to be useful for understanding, but you will not have to implement them yourself, Thermoptim doing it implicitly for you.

However, the first exercise on gas turbines (model with air considered as a perfect gas) being one of the few to be treated analytically as well as with the software, a comparison is made between the two approaches.

This course does not address in detail the fundamentals of thermodynamics, assumed already known. Reminder sessions are proposed, however. You are advised to browse through them at least once, if only for you to get used to the notations used.

It is particularly important that you understand the concepts of open or closed system and that of enthalpy, because they will be used permanently later. Similarly, although the fluid properties are assumed to be known, experience has shown that reminders are usually necessary, especially their representation in the various thermodynamic charts.

This is also during this step that you will learn using the simulator you will use throughout this course to model energy systems. Diapason session S07En_init First steps with Thermoptim will make you discover the features of the software. In addition, three examples present step by step the construction of models (gas turbines, steam power plant cycle, compression refrigeration machine), to help you take control of the tool.

The learning of energy conversion includes two parts of very different nature but of similar difficulty:

• firstly the modeling of technologies studied, which is primarily applied thermodynamics

• secondly the understanding of the technologies used, which differ quite widely depending on the type of machine

You will have to study both these two issues, sometimes completely separate, sometimes combined. Take the time to study the technologies presented, and feel free to supplement the information provided to you because they are necessarily brief and incomplete. For this you will find external references we recommend you to refer to.

As you will see, energy technologies can be considered as systems involving a limited number of components, whose behavior it is important to understand, at least qualitatively. The sequence proposed is to first study the components, and then systems.

As the Diapason sessions for technologies have not been yet translated, you will be directed to the thematic pages of the portal where they are presented.

So that you can quickly enter into the heart of the matter, you will begin by studying two types of components, firstly those that perform the compression and expansion, and secondly those in which fluids are heated or cooled.

With this background, you can build the cycle of a simplified gas turbine or that of a steam power plant.

The corresponding technology is presented in the following thematic pages:

• displacement compressors

• dynamic compressors

• turbines

Subsequently, the study of combustion will give you access to realistic gas turbine modeling, and that of isenthalpic expansion without work to refrigeration machines.

The corresponding technology is presented in the following thematic pages:

• combustion chambers

• boilers

• expansion valves

The corresponding Diapason sessions are listed in the table below.

Finally, you will approach the study of reciprocating internal combustion engines (diesel and gasoline), but only in terms of technology, modeling, much harder than for the other cycles, being performed in the second step.

The study of basic cycles is extremely important because it will allow you to structure your knowledge of energy powered systems. The dual discursive and graphical approach proposed here will help you in this task.

When studying cycles, comparisons with the Carnot cycle allow you to make interesting qualitative analyses based on the shape of the cycles and the nature of the irreversibilities encountered. Therefore discussions on this topic are included in some of the Diapason sessions presented below.

As mentioned in the previous section on technology, the sequence proposed is as follows:

Gas turbine

Start by studying gas turbine technology, presented in the following thematic pages . They explain the architecture of the machine, its principle of operation and how it can be modeled (assumptions, sequence of calculation steps).

The begin by building a simplified gas turbine model: the GT is first modeled as if the working fluid were air considered as a perfect gas, without combustion. A comparison can be made with the analytical solution, which incidentally shows that the simulator leads to the same results as theoretical equations with these simplified assumptions. The plot of the cycle on the (T, s) chart is explained.

In a second model, the working fluid is air considered as an ideal gas. A comparison is made between results provided by both models. It shows that the perfect gas assumption leads to significant errors and that the ideal gas model is more precise. As analytical calculations become cumbersome, the value of modeling with the simulator is highlighted.

These models are presented in session S21En Gas turbine exercise (air as working fluid) .

In a third model the combustion is taken into account (session S22En Gas turbine exercise (combustion) ). Obviously calculating combustion by hand would be lengthy and difficult, which further justifies using the simulator.

It is of course also possible to directly model the gas turbine with combustion (session S24En Simple gas turbine exercise ). Note that one of the Thermoptim Getting Started Guides also explains how to build such a model, the settings being slightly different.

Steam power plant

Start by studying steam power plant technology, presented in the following thematic pages. They explain the architecture of the plant, its principle of operation and how it can be modeled (assumptions, sequence of calculation steps).

A simple steam power plant model is presented in session S26En 300 MW simple steam cycle . The plot of the cycle on the (T, s) and (h, P) charts is explained.

Vapor compression refrigeration machine

Start by studying vapor compression refrigeration technology, presented in the following thematic pages . They explain the architecture of the machine, its principle of operation and how it can be modeled (assumptions, sequence of calculation steps).

A R12 water chiller model is presented in session S31En Water chiller exercise . At the end of the exercise, the refrigerant is replaced by R134a, much less harmful to the environment. The plot of the cycle on the (T, s) and (h, P) charts is explained.

Reciprocating internal combustion engines

At this stage, modeling reciprocating internal combustion engines remains a bit too complicated.

We therefore suggest that you just start studying their technology in the thematic pages dedicated to them.

The operation of 4 stroke and 2 stroke cycles is presented in session S35En_4t2t 4 and 2 stroke engines .