Experimental evaluation of electronic and thermostatic expansion valves performances using R22 and R407C

An experimental study to evaluate the energetic performances in steady-state and in transient operating modes of an electronic and thermostatic expansion valve is presented. Both valves have been assembled to feed an air cooled evaporator connected to an experimental vapour compression plant with a water cooled condenser operating with a semihermetic compressor. The performances of the valves have been examined at different conditions when the experimental plant works with R22 and with a substitute as the nonazeotropic blend R407C that is chlorine free. Indeed the HCFC designated as R22 contains chlorine that is harmful for the ozone layer and must be replaced in the future. The final results of this study show an overall better performance of the electronic expansion valve compared with the thermostatic expansion valve under transient conditions while in steady-state conditions both the valves are equal in performance. These results apply to both R22 and R407C. (C) 2001 Elsevier Science Ltd. All rights reserved.