DESIGN, CFD ANALYSIS AND PERFORMANCE EVALUATION OF COMBINED STEAM EJECTOR SINGLE EFFECT LIBR/H2O ABSORPTION REFRIGERATION SYSTEM

Abstract

The objective of this work is to develop the efficiency of vapour absorption system by addition the steam ejector cycle. Computational fluid dynamics (CFD) is a numerical implement that is greatly accurate to simulate a high number of applications and developments. The CFD analysis has appeared as a viable skill to provide dynamic and efficient design solutions. In this work a CFD analysis concentrate on the mathematical simulation of the operating of a steam ejector to develop the Efficiency of vapour absorption cycle using LiBr/H2O as a working refrigerant for this system and operating under steadystate conditions. The overall design steam ejector technique that follows ASHRAE and ESDU recommended are considered in this study, throat nozzle diameter of 4.13 mm, and suction maxing chamber diameter of 10 mm. The effect of different operational settings on the performance of the steam ejector operating in combination with a single effect absorption system was measured. The geometrical model and meshing is done with solid works and ANSYS FLUENT solver is used for the analysis. In this research study, development to the system is achieved by utilizing the potential kinetic energy of the ejector to enhance refrigeration efficiency. The effects of the entrainment ratio of the ejector, primary and secondary operating temperature, on the condition condenser pressure and temperature and system performance have been studied. The results showed that the entrainment ratio is found to increase with the decrease of secondary pressure (evaporator pressure) and consequently, the entrainment ratio is also found to increase with increase of generator temperature keeping the evaporator temperature and condenser pressure constant. The entrainment ratio does not vary much with the condenser pressure until the critical condenser pressure. The COP of the established system is developed by up to 45% compared with that Basic system at the given condition.