Pumped Recirculators vs CPR Feed

The controversy over CPRs vs. pumped recirculators has gone on for many years. Despite numerous articles and papers, each claiming energy savings for its approach, the problem has not been fully analyzed from a fundamental standpoint. Using the simple concept of conservation of mass, and employing thermodynamic properties of refrigerants, a mass and energy balance can be modeled for each type of system. This approach yields equations which can then be used to predict the mass flows required for each type of system. This allows the systems to be compared to each other in a scientific manner. The paper will illustrate how feeding cold liquid to the evaporators lowers pressure drops and increases overall system efficiencies.