Preliminary design and simulation of an innovative Rotary Supersonic Nozzles Expander apparatus for natural gas liquefaction and general refrigeration processes

Abstract

An innovative method and a supersonic expansion apparatus proposed for the natural gas liquefaction process and the potential to use in general Refrigeration purposes, gases separation, CO2 capture and air conditioning. The current study presented the innovated apparatus features preliminarily, described its design basics and working principles, and outlined general schemes of approached method implementations. The apparatus named the Rotary Supersonic Nozzles expander. The apparatus designed on the basis of the compressible flow and the fundamentals of the Laval nozzle and the supersonic separation process. It is an Expansion bladeless turbomachinery utilizes the propulsion reaction principles of the Rocketry Engines. The numerical analysis and CFD simulations were conducted to investigate the influences of the nozzle backward reaction velocity on the supersonic flow distributions and to determine the enhancements achieved in the gas cooling and condensation processes by the proposed apparatus compared with the existing supersonic separators. CFD executed based on the anticipated nucleation theories and condensation models. Simulation results confirmed that fluid stagnation properties in the proposed apparatus exposed unacquainted behaviors during the rotational motion and their distributions diminished along the nozzles. The proposed apparatus obtained an extraordinary improvement in the supersonic expansion and condensation process. The estimated maximum nucleation rate 1.80707e + 037 m−3 s−1, which was about 10e + 14 times the existing rate in the statical nozzle at the same conditions. Similarly, the estimated maximum droplets number and mass transfer rate were about 10e + 08 and 14 times respectively. The obtained maximum liquid mass fraction was 0.6 and 5.75 times more than that achieved by the static nozzle. Furthermore, the estimated shaft power recovery was>50 % of the required power to obtain the same compression ratio.