Performance and economic comparison of three annual air-conditioning systems in sow houses

Abstract

Huge amounts of energy is usually consumed by intensive pig farms and the supply systems based on renewable energy and heat recovery contributes to reducing the reliance of fossil fuels. In order to determine the performance advantages and economic feasibility of a new spray cooling system with photovoltaic/thermal and heat recovery, it is compared with the two traditional air-conditioning systems in sow houses. Firstly, the models are established for three systems and the reliability is verified for their core component models. The results show that the maximum error is less than 12.9 % for the models. Meanwhile, the performance parameters and CO2 emissions are compared for three systems under different indoor load rates. The results show that compared with other two systems, the new system has significant performance advantages and social benefits. Specifically, the annual exergy efficiency and energy efficiency ratio of new system are at most 28.36 % and 28.45 % higher than those of other two systems, respectively. However, its annual energy consumption and CO2 emissions are at most 82.32 % and 87.90 % lower than those of other two systems, respectively. Finally, an economic study is performed for three systems. The results show that the initial investment of new system is at most 230.67 % higher than that of other two systems, while its annual operating and maintenance costs are at most 81.60 % lower than those of other two systems. Especially, compared with other two systems, the relative investment payback period of new system is at most 4 years. In summary, this research can provide guidance for the practical application of multiple energy coupling supply systems in intensive pig farms so as to improve their energy utilization efficiency and economic benefits.