Modelling and Optimization of Double Choking Ejectors for Refrigeration Systems

Abstract

The aim of the work was to investigate effect of pressure difference of primary and secondary flow of double choking system on the system performance by analytically using MATLAB tools.  The geometrical variable such as mixing chamber diameter, length of mixing chamber and other geometrical parameter were varied to vary the pressure difference of primary and secondary flow.  Analytical results show that nozzle exit conditions influence the mixing chamber, primary exit, and secondary flow of the fluid. Varying condenser pressure and geometrical parameters had a large impact on entrainment ratio and thus performance of ejector refrigeration. If the length of the convergent section of the ejector is lesser than the value calculated for the deflected primary flow, the primary flow will hit the wall of the convergent section and create a barrier for the secondary flow. Ejector refrigeration system can replace the conventional vapour compression refrigeration systems as it is more environmental friendly and uses less power.