Energy networks constitute a crucial portion of the energy infrastructures. Pipelines are currently the main way to transport gas at an international level and distribute it within countries. The electricity grid, both at the transmission and distribution level, is crucial for the exploitation of renewable energy sources (RES) at the core of the energy transition. Thermal networks for district heating and cooling are also gaining attention due to the large availability of renewable or waste heat. In addition, all these networks allow an easier conversion of energy flows, from power to gas (or fuel in general) and to heat/cold, from gas to power etc. In this regard, it is worth mentioning that there is a huge interest in the scientific and industrial community to explore pathways for the mutual integration of energy networks towards flexible multi-energy carriers systems. This course is focused on the main energy networks and aims at providing the student with the ability to analyze and model electricity, gas and thermal networks. A technical description of these assets is provided together with a detailed information related with the modeling approaches. Current and future trends are described, also considering the interaction between the various networks. A relevant part of the course is dedicated to the development of a practical project related with the design and analysis of the energy networks.

At the end of this course, students are expected to acquire detailed knowledge about the design and operation of electricity, gas and heat networks. In addition the ability to simulate the various energy networks should be developed. In the case of thermal networks, the student is expected to learn how to solve the fluid dynamic behavior of three-shaped and loop networks considering a one-dimensional approach. In addition, the techniques for solving thermal behavior of the network and the related issues should be understood, together with the ability to apply to practical cases. For gas networks, the student will learn how to extend the momentum and energy equations to compressible fluids such as natural gas and how to model complex fuel mixtures that can be transported in gas pipelines. Indeed, innovation in natural gas industry is looking at the multi-injection of gas resources into the gas networks including fuels from LNG route, biofuels (i.e., biomethane) and hydrogen from power-to-gas. For electricity network the student will learn the structure and the role they play in energy systems with an outlook on the interchanges with other commodities. The mathematical modelling of the network in steady state along with the main operational requirements (frequency and voltage) are introduced. The emerging challenges (RES, storage, P2x) are introduces in the framework of the energy trilemma 8sustainability, security equity)

Engineering thermodynamics and heat transfer. Computational language.

Introduction to the main energy trades. Thermal networks: current situation worldwide and trends. Technical characteristics of thermal networks. The main components: heat sources, transport and distribution pipelines, thermal substations, pumping systems. Behavior of buildings. Thermal storage. From the first to the fourth generation district heating. Fluid dynamic calculation: from 3D to 1D. Fundamentals of graph theory. Solution of the fluid flow problem for a network. The SIMPLE algorithm and its implementation. Solution of the thermal problem. The upwind scheme. Numerical diffusion and possible algorithms to overcome this issue. Application to a network (work to be developed in groups). Analysis of real networks. Gas networks: technical description of gas networks from transmission to distribution level. Pipeline description, gas quality and interchangebility. Momentum and energy equation, adaptation for the modelling of gas pipelines and networks. Modelling of non-pipe elements (i.e. compressors, reduction station). Simulation of gas networks with multiple fuel injection: fluid-dynamic effects, gas quality effect, linepack management. Electricity networks: structure of electrical energy systems (generation, transmission, distribution and utilization). Definitions of adequacy and security. The operation of electricity network in normal state: power frequency regulation and voltage control. The steady state operation of electricity networks: power flow equations (AC and linearized DC, backward and forward sweep), solution techniques. Application of real systems with dedicated graphical SW. Electricity networks in energy transition: penetration of renewables and inertia problems, storage e multi commodity transformation of electricity. Multiscale electricity networks from global interconnections to smart grids. The impacts of networks in electricity markets.

The course in organized with theoretical lessons and practices in lab. During lessons the technical aspects related with the energy networks and modeling techniques will be developed. A relevant part of the course is devoted to project team working using proper language software for the design and simulation of energy networks.

Teaching material provided by the teachers

Modalità di esame: Prova scritta tramite PC con l'utilizzo della piattaforma di ateneo; Elaborato progettuale in gruppo;

The final mark is composed by the written test for 24/30 and for 6/30 by the group project. The written test is composed of questions (both open and multiple choice). This part aims at evaluating the specific knowledge of the student concerning the technical aspects related with energy networks as well as the ability of the student to apply the numerical modeling techniques. The group project is specifically designed in order to make the student familiar with the application of the modeling techniques. The specific contribution of students is assessed through proper questions in the written test which are tailored on each specific project. The exam structure is the same considering both the cases in which it is performed in the exam room or from remote.

Modalità di esame: Prova scritta tramite PC con l'utilizzo della piattaforma di ateneo; Elaborato progettuale in gruppo;

The final mark is composed by the written test for 24/30 and for 6/30 by the group project. The written test is composed of questions (both open and multiple choice). This part aims at evaluating the specific knowledge of the student concerning the technical aspects related with energy networks as well as the ability of the student to apply the numerical modeling techniques. The group project is specifically designed in order to make the student familiar with the application of the modeling techniques. The specific contribution of students is assessed through proper questions in the written test which are tailored on each specific project. The exam structure is the same considering both the cases in which it is performed in the exam room or from remote.