Speaker
Description
The Cryogenic Moderator System (CMS) at the European Spallation Source (ESS) is designed to supply liquid parahydrogen at 17.5 K and 1 MPa for efficient neutron moderation. The hydrogen flow is circulated with the help of a series of two pumps through a piping network (CMS loop) with various components, including heat exchangers, tanks, valves and piping elements such as straight pipes, bends, reducers, corrugated pipes, and branching sections etc. Ensuring optimal hydrogen flow requires accurate estimation of pressure drops across CMS piping network to find out the operating point on the pump characteristics curve that matches with the system pressure drop at different flow rates However, there may be uncertainty in the existing correlations for estimating pressure drops used for non-cryogenic fluids for accurate prediction of this parameter in a parahydrogen flow system. This study utilizes computational fluid dynamics (CFD) simulations to calculate these pressure drops and derives component-specific pressure drop correlations. These correlations can be integrated into a simulation code to estimate flow rate iteratively that will match the pump performance curves. These can aid in predicting optimized operating points, enhancing the CMS efficiency by manipulating pump speed and valve operating characteristics. This work, thus contributes to the precise control and reliable operation of the Cryogenic Moderator System for ESS.
