No abstract

An optimized equipment design for natural gas processing and liquefaction plants becomes increasingly difficult with changing process conditions: Particularly low values of surface tension create rising challenges on the design of phase separators and column internals. The TERESA test rig at HZDR was designed to allow the investigation of multiphase thermohydraulics and phase separator performance under critical fluid properties in industrial dimensions. A versatile pipe test section is available in DN200 and equipment internals may be tested in a sectional DN300/DN500 test separator. The applied test fluid shows a high vapor-liquid density difference between 1470 and 940 kg m -3 , viscosity as low as 0.12 mm 2 s -1 , and surface tension down to 1.3 mN m -1 . Volumetric liquid and vapor flow rates may be varied up to 9 and 530 m 3 h -1 in the test rig, respectively.

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Tailored conditioning and control of flashing feeds in industrial applications requires knowledge of the evolving flow morphology and phase fractions along the feed pipe. Design methods obtained from reference systems (e.g. water-air) are hardly applicable for commercial scales and critical fluid properties (e.g. high vapor densities, low surface tension). In this study, the flow morphology of flashing feeds in a novel refrigerant test rig at critical fluid properties was analyzed using wire-mesh sensors at two locations along the feed pipe and experimental data from the water-air system.

Wire mesh flooding point measurements at low surface tension < 10 mN m -1 were conducted using a refrigerant as model fluid. A new method for the calculation of wire mesh capacity was developed based on experimental data from literature and data from this study. In comparison to the well-known and widely adapted K-value method given in the Gas Processors Suppliers Association (GPSA) Engineering Databook and various other sources, the new method yields 3-38 % reduced wire mesh cross sections for fluid systems at pressures above 20 bar(a) while retaining an inherent safety margin.