Modélisation et expérimentation d’une installation frigorifique à éjection Gaz-Gaz.

Abstract

The main objective of this research project is to study the effect of droplet injection at the outlet of the ejector in an ejector refrigeration system destined for air conditioning and refrigeration, to see the potential effects of drops on the performance parameters of the ejector-based refrigeration cycle. To this end, a numerical and experimental approach is put in place and has been separated into two parts to study the phenomenon. The experimental part is carried out in the Hydro-Québec Shawinigan Canada research laboratory with over a hundred tests developed on a prototype with a nominal cooling capacity of 35 kW. Using the refrigerant R245fa as a working fluid. The tests were realized by varying the following parameters: the flow rate of the primary fluid (ranging from 0.33 to 0.43 kg / s) as well as the temperatures of the heat transfer fluids at the inlet of the generator (81 to 85 °C) and the evaporator (13 to 15 °C) and coolant at the condenser inlet (20 to 28 °C). Statistical analysis is developed for a better evaluation of the experimental results. In the numerical part, several thermodynamic models are developed for each cycle component under Matlab R2017b software, with a particular emphasis on the one-dimensional thermodynamic model of the ejector based on the energy,mass, and momentum conservation equations. The ℇ-NUT method is used for each 'one of the models of the heat exchangers (generator, condenser, and evaporator). The device of the injection of drops at the exit of the ejector, the numerical results are validated thereafter with the experimental data made in the LTE laboratory of Hydro-Quebec. Shawinigan. Canada. The obtained results are very interesting for understanding the complex phenomena that have occurred within the ejector. With a good match between the numerical and experimental results. With an improvement in the coefficient of performance.