Experiment Investigation of Air Blast Freezer in a Cascade Refrigeration System with R290/R32 for Vannamei Shrimp

Abstract

Indonesia is one of the main shrimp exporters with a total production of 1.21 million tons or IDR 79.21 trillion in 2021. However, only 20.89% of this production is exported due to technological limitations in maintaining shrimp freshness due to the growth of microorganisms such as bacteria, fungi, and yeast. This research aims to develop a quick freezing system using the Air Blast Freezing (ABF) method in a cascade refrigeration system with environmentally friendly refrigerants, namely R290 and R32, at temperatures up to -40℃. The aim of this study is to investigate the performance of the air blast freezer system at several cooling loads, evaporator fan flow rate and refrigerant pressure at the HTC compressor. Tests were conducted with variations in shrimp weight (1kg, 3kg, and 5kg), air flow rate at the evaporator fan (3.1 m/s, 3.2 m/s, and 3.3 m/s), and refrigerant pressure at the compressor (12 bar, 13 bar, and 14 bar). The results showed that the COP (Coefficient of Performance) increased with increasing shrimp weight and airflow velocity, with the highest pressure at 14 bar providing the best performance. The evaporator temperature reached -42.37℃, allowing effective freezing of 5kg shrimp with a COP of 1.334.