Thermal-hydraulic separators unveiled

A key issue in the design of heating/cooling networks consists in attaining the hydraulic independence of the connected circuits while simultaneously providing the required flow rate of thermal fluid at the design temperature under different operation loads. In this respect, thermal- hydraulic separators offer a valid alternative over other devices used for the same service (as, e.g., heat exchangers, accumulation tanks or double-tee junctions), providing the opportunity to integrate the functions of de-gassing and of removal of solid debris in a single piece of equipment.The present numerical investigation improves the characterization and modelling of these devices. The major outcome of the proposed research is the improvement of the base model widely-used in the design of thermal-hydraulic networks encompassing thermal-hydraulic sep-arators. The proposed model accounts for the turbulent mixing within the device. Furthermore, we propose an original network representation of thermal-hydraulic separators, which supports the physical intuition about their internal flow patterns and can be integrated in thermal network solvers used for plant design and optimization. To the authors' best knowledge, this is the first numerical investigation accounting for the impact of the internal mesh strainer on the behaviour of the device.