Multi-physics Modeling of Technological Systems

9Thermal Power Conversion

Summary

This chapter completes the book with modeling of systems that convert thermal power into mechanical power and vice versa, by means of a compressible fluid. As a first step, several fluid models and notions of thermodynamics are presented. These are useful when modeling thermodynamic cycles and components of heat engines. The models presented are defined for steady state and have a level of complexity that enables their use in a system approach. Analysis or simulation illustrations of the use of these models are provided by examples of thermal power plants and heat pumps (HPs).

Learning outcomes

On completing this chapter, the reader is expected to be able to:

• – Model the thermodynamic behavior of a gas using the ideal gas law;
• – Model the components of heat engines such as compressors and turbines;
• – Model the behavior of a heat engine;
• – Find all the state variables of a fluid using thermodynamic diagrams, such as the s-T or p-h diagram;
• – Find the final state of a fluid that undergoes an elementary thermodynamic process;
• – Use s-T and p-h diagrams to represent the thermodynamic cycle of a heat engine;
• – Calculate the power and the efficiency of a heat engine, such as a thermal power plant or an HP.

9.1. Several examples of heat engines

Following the invention of the steam engine, many other engines were developed; their purpose is the same, namely, the conversion of thermal energy into mechanical work. Moreover, nowadays there are engines ...