Minimization of Unit Freezing Costs for In-Line Freezing Systems

摘要

The variables influencing how a given product freezes in an automatic in-line freezing system are time, temperature of the freezing medium, and heat transfer between the product and the freezing medium. This paper describes a design methodology to evaluate product freezing times, freezer capacity, and refrigeration load for such systems. The methodology estimates evaporator performance and product freezing time from first principles and determines the equilibrium between cooling load and evaporator capacity iteratively. The paper includes sensitivity analyses showing influence of evaporating temperature, product temperatures, air velocity, evaporator fouling, and product packaging on freezer performance. Finally, the paper shows a method to determine the minimum unit energy consumption point.