KEYWORD |
Nemo
Theses at Politecnico
Investigation of natural circulation dynamics in presence of distributed heat sources
Reference persons ROBERTO ZANINO
External reference persons Prof. Lelio Luzzi, Dipartimento di Energia, Politecnico di Milano
Research Groups Nemo
Description Background
DYNASTY (DYnamics of NAtural circulation for molten SalT internallY heated) is a natural circulation loop built at the Energy Dept. Labs of Politecnico di Milano (POLIMI), and aimed at studying the dynamics of natural circulation in presence of distributed heat sources [1,2]. Although several works have been carried out on the analysis of free convection loops with localized hot and cold heat sinks ("conventional" natural circulation case), the instance of an internal and distributed power source inside the system has been little investigated. The effects of the internal heat generation on the dynamic behaviour of natural circulation have been highlighted by semi-analytical and numerical models recently developed at POLIMI [3-6], and DYNASTY will provide the required data to perform their validation.
The DYNASTY facility is going to be extended, in the frame of the H2020 SAMOFAR Project (http://samofar.eu/), to include a passive Decay Heat Removal (DHR) system. The upgraded facility, called eDYNASTY, has been designed and commissioned. It will be coupled with the DYNASTY primary loop to investigate the dynamic behaviour of the two coupled systems (primary loop + DHR system).
Aim of the work
In the first part of the work, experimental investigation of the natural circulation dynamics in presence of distributed heat generation will be carried out by means of DYNASTY, with a specific focus on the analysis of mass flow instabilities. The experimental campaign will provide the data for assessing/refining the theoretical models developed on purpose to study this phenomenology.
The second part of the thesis will deal with the extension of DYNASTY to investigate the coupled dynamics of primary loop and passive DHR system. In order to study the asymptotic dynamics of the two coupled systems, the equilibrium stability will be analysed adopting the tools provided by linear analysis. The obtained results will be collected in the so-called stability maps. In parallel, a nonlinear 1-D Modelica model and a nonlinear 3-D CFD model will be developed for a complete description of eDYNASTY dynamics.
Deadline 10/07/2018
PROPONI LA TUA CANDIDATURA