Thermodynamic comparison of various refrigerants for an on-board R290 refrigeration system with economizer subcooling in small fishing boats

Abstract

The Indian seafood sector faces a critical challenge in maintaining fish quality and reducing post-harvest losses, primarily due to inefficient cooling practices on small fishing vessels. This inefficiency not only reduces fishers’ income but also significantly contributes to greenhouse gas emissions, both through methane released during food degradation and the increased energy consumption of cooling systems. Given the vital role of seafood in ensuring food and nutritional security and its substantial contribution to export revenues, the availability of refrigeration facilities on small fishing boats is essential. Implementing such solutions could play a pivotal role in mitigating food loss and enhancing the livelihoods of fishers. This study evaluates the performance of a natural refrigerant-based on-board cooling system designed for small fishing vessels along with heat recovery prospect for Clean in Place (CIP) application. The performance and environmental impact of the proposed R290 (Propane) system are evaluated against two alternative systems using R404A and R407A. Real compressor equations were employed to assess system performance, and the potential benefits of incorporating economizer subcooling were also explored. The cooling COP of the proposed system was found to be 13.4 % and 13 % higher than the R404A and R407A systems, respectively. Despite a reduction in heat recovery potential due to subcooling, the overall COP is enhanced by an additional 7.1 %–7.9 % due to higher cooling effect. The Return on Investment (ROI) for the R290-based on-board refrigeration system is approximately seven fishing trips (14 months), highlighting its environmental and economic viability for small fishing vessels.