Experimental performance analysis of a biogas energy assisted hybrid milk cooling system

Abstract

Biogas energy assisted hybrid milk cooling system was investigated experimentally, in this study. The system operated in a cycle. Primarily, biogas was obtained from the residues of animals in the farm environment and an internal combustion gas engine is started with this gas. Then, the gas engine provided the power required for the compressor of the cooling system to operate. The main purpose of the study was to encounter the energy required for milk cooling only from the biomass potential of animal wastes and in this way, it was to bring a system with high energy efficiency for milk cooling process to the literature and industry. In experiments, 150 liters of milk in the first milking and 300 liters of milk in the last milking were cooled. It was determined that the energy consumption in the first and last milking is 2.29 kWh and 2.54 kWh. The results revealed that this developed system was 45.61% and 41.61% more advantageous for first and last milking, respectively, compared to conventional milk cooling systems in terms of energy consumption. When the system compared to other alternative energy source assisted milk cooling technologies with similar milk cooling capacity, It was observed that 14.55% and 24.40% more efficient with regards to energy consumption for the first and last milking. Additionally, experimental and Carnot COP values of the cooling system were determined as 4.29 and 8.26, respectively. These data revealed that the hybrid system had a higher performance of 38.4% compared to other milk cooling techniques.