Helium turbine expanders are widely used in low-temperature refrigeration applications, and the efficiency and performance of their brake impellers directly impact the overall equipment efficiency and stability. This study employs the computational fluid dynamics (CFD) software ANSYS CFX to analyze the performance characteristics of ten brake impellers of varying sizes in helium turbine...
The sorption pump is a critical component of helium sorption cryocoolers operating in the liquid helium temperature range. Current research on porous materials for sorption pumps predominantly focuses on activated carbon, with limited exploration of alternative porous materials such as carbon nanotubes. Due to differences in elemental composition and molecular structure, the helium adsorption...
The efficient and long-term storage of cryogenic liquids, such as liquid oxygen and liquefied natural gas, relies heavily on the use of various insulation materials. However, the apparent thermal conductivity data for many insulation materials, including foam glass slabs, high-density polyisocyanurate, and aerogel, under cryogenic and atmospheric pressure conditions remain insufficiently...
The transient heat transfer in superfluid helium (He II) from curved surfaces presents unique features that differ significantly from planar geometries. We numerically investigate this process by solving the two-fluid model coupled with Vinen's equation for vortex-line density, focusing on how surface curvature affects the propagation of the second sound wave. The numerical model is first...
The helium turbine expander is one of the core components of a helium cryogenic system. The operation of the helium turbine expander varies during variable load adjustments in a helium cryogenic system, and has significant time-varying characteristics. In this paper, numerical simulations are conducted to investigate the time-varying flow field characteristics of the helium turbine during...
Notable cost is invested in the liquification of cryogenic fluids such as liquid Nitrogen, Helium, Hydrogen, and Argon. End users have an interest in knowing the level of heat leak cryogenic systems experience, and convenient methods of heat leak calculations. End-users value pump designs that minimize heat leak in cryogenic systems to improve system efficiency and reduce operating costs. At...
