Compact physical model for simulation of thermal networks

Optimal design and management of DH networks require numerical models for simulating the physicalbehavior of the network in various operating conditions. DH network models usually rely on the physicaldescription of thefluid-dynamic and thermal behaviours. The use of physical models can represent alimitation in various cases: a) when extended networks are considered (several thousands of nodes); b)when multiple simulations are required in real-time; c) when multi-energy networks are optimized. Inthese cases, compact models are preferable.This work aims at presenting the compact model for fast simulation of thermal transients. The modelpreserves the reliability of a physical model because it solves the mass and energy equation. Only themomentum equation is simplified in order to overcome complexity related to the iterative solution ofmass and momentum equations, which are coupled.Results of the application to a real network show that the proposed methodology significantly reducescomputational costs with respect to a complete physical model, with small impact on the accuracy. Theapproach is suitable for being used in combination with other network models (gas, electricity) and withmodels of other energy infrastructures, such as plants, storage units or energy conversion systems.