Development of a Chest Freezer – Optimum Design of an Evaporator Coil

Abstract

In a country such as India, food grains, fruit, vegetables, meat, poultry and fish, are very susceptible to microbial contamination and spoilage and require stringent preservation methods. One such method is by the use of a chest freezer for the storage of frozen food. This investigation considers different loads and design parameters for the development of a chest freezer using R134a as the working fluid. Experimental designs of an evaporator coil, condenser coil and capillary tube are investigated through the development of storage periods in terms of steady state and cyclic performance, by optimising the quantity of refrigerant charge, with strict adherence to the standards and requirement for maintaining an internal temperature of -23 °C at 43 °C ambient. Cyclic load performance tests optimise the performance of individual components selected for the design of a chest freezer. The system selection has a highly balanced performance with R134a and showed 118 kJ/kg cooling capacity with 8.42 coefficient of performance (COP). By the replacement of R134a, temperatures of -23 °C are maintained inside the freezer cabinet with low power consumption and an increase in the net refrigerating effect, which in turn increases the COP. The system design has optimum efficiency with moderate costs by optimising the length and diameter of the evaporator coil, i.e., 34.15 m and 7.94 mm, respectively.