Experimental setup design for multi-purpose Ranque-Hilsch vortex tube investigation

The paper presents design considerations for experimental investigation of the Ranque-Hilsch vortex tube effect (VT). The research aims to find physical mechanisms governing the thermal and mass separation of non-homogenous gases entering the VT. Also, an approach to study phase-change phenomena inside the VT will be undertaken to evaluate the applicability of the VT in refrigeration systems. For this purpose, it is essential to have a mutually validated experimental setup and numerical model. The 1st generation test rig was based on a VT of 36 mm inner diameter and up to 1.62 m length. With inlet air supply at 3 bar abs, it was possible to achieve outlet temperature values from 0.1 C at the cold side to 42.3 C at the hot side, and the maximum air flow was 123 kg/h. The 2nd generation should be reduced in size for two reasons. First, lighter and heavier gases (helium, carbon dioxide) will be supplied from pressurized cylinders and mixed with air or nitrogen. The flow rate should be minimized to enable a continuous operation from the pressurized cylinders. Second, to apply higher inlet pressure, it is required to reduce the flow channels to maintain the gas flow below the technical limit of about 60...100 kg/h. The proposed test rig configuration is based on two supply options. In the first option, pure gases can be supplied from batteries (bundles) of pressurized cylinders, and then mixed to achieve the desired composition. The second option can be obtained by connecting the test installation to an air compressor, which is more suitable for test operation or for multiple-parameter measurements required to obtain boundary conditions for numerical modelling. Moreover, the test rig will be extended to include a multi-phase flow unit with a liquid dosing and separation equipment.