A simulation methodology for heat and cold distribution in thermo-hydronic networks

This paper presents a simulation methodology to analyze hydronic heat distribution systems in a fast and user friendly way. As suggested in its name, the “Base Circuit Methodology” (BCM) is based on the observation that thermo-hydronic networks can be built up as a modular composition of elementary “Base Circuits” (BCs). Once the hydronic and thermodynamic behavior of such basic components is described in a set of dedicated equations, complex thermal distribution networks can easily be modeled by connecting the basic sub models. In addition to control performance simulations (accuracy, stability, speed) the BCM puts extra effort into energy efficiency analysis. In fact, every BC is a local sub unit in which heat flows are gathered, divided or changed in terms of temperature and/or flow. Therefore the BCM model setup yields the opportunity to analyze the net heat transport and its adaptations while crossing the network. Doing so, system designers get the efficiency variables more structured, leading to straightforward abilities to optimize heat and cold distribution. Practical examples prove the benefits of the methodology. Moreover, a test installation was built in which flows, pressures, and temperatures are confronted with the simulation results. The simulations are processed by means of the iterative equation solver EES (Engineering Equation Solver; ©F-chart) which has been experienced as a very compliant software package. As a result the methodology is delivered as a validated and open source library.