Experimental energetic analysis of a vapor compression refrigeration system with dedicated mechanical sub-cooling

In this work, an experimental investigation into the effects, in terms of energy, of employing a dedicated mechanical subcooling cycle with a residential 1.5. ton simple vapor compression refrigeration system is presented. A comparative analysis of the experimental cycle performance is conducted with and without the dedicated subcooler cycle when the room temperature is kept between 18 and 22 °C. This is done in order to ascertain the percentage increase in efficiency due to use of a dedicated subcooling loop. R22 is employed as the refrigerant in the main cycle whereas R12 is flowing in the dedicated subcooling cycle. The experimental outcomes indicate that the load carrying capacity of the evaporator increased by approximately 0.5. kW when R22 was subcooled, in the main cycle, by 5-8 °C. It was also noted that, by using the subcooling, the second-law efficiency of the cycle increased by an average of 21%. Furthermore, the general trend indicated that this percentage increase is inversely proportional to the ambient temperature variation. The experimental work proves that dedicated subcooling can be used for increasing cooling capacity and efficiency.