Operation performance of an ultralow temperature cascade refrigeration freezer with environmentally friendly refrigerants R290-R170

In the present study, the operation performance of an ultralow temperature cascade refrigeration freezer is experimentally measured. The natural refrigerants R290-R170 are adopted as high temperature and low temperature fluid. The experimental test is conducted in a Type laboratory with a dry bulb temperature of 32.0oC and wet bulb temperature of 26.5oC. Different state monitors are set to display the system performance variation, and several temperature monitors are arranged to study the pull-down and temperature variation in freezer. Based on established experimental rig, three freezing temperatures, including − 40oC, -80oC and − 86oC, are measured and compared. It is found that for different freezing temperatures, most of space in freezer can be pulled down to the target temperature. With some new findings achieved, the present work is significant to enrich the ultralow temperature refrigeration experiment data and supply some suggestions on optimism of ultralow temperature cascade refrigeration system.