Performance of a new evaporative misting system based on photovoltaic/thermal and ventilation heat exchange in sow farms: a case study in Guangzhou, China

Abstract In order to improve the regional applicability of existing evaporative misting systems, a new evaporative misting system based on photovoltaic/thermal and ventilation heat exchange is proposed for sow farms. Compared to traditional systems, the proposed system can help to improve their regional applicability and reduce their energy consumption. Meanwhile, its simulation model is constructed and the reliability is verified for its core equipment. The maximum error is less than 14.5% for the above models. Through simulation, the optimal regulation variable ranges in the proposed system are determined for mass flow rate of working fluid (MFWF) and misting power by analysing its operating characteristics. The results show that its optimal ranges of MFWF and misting power are 7245–9245 kg/h and 40–45 kW, respectively. The annual performance is further quantified and analysed under different load ratios for the proposed system in Guangzhou. It can be found that the annual exergy loss, heat exchange coefficient and solar energy benefits of the proposed system in Guangzhou are negatively correlated with load ratio, but its annual energy consumption and energy efficiency ratio are positively correlated. Meanwhile, the system performance and benefits are not significantly improved by increasing device investment and sow density when load ratio exceeds 120% in sow farms. The above conclusion can contribute to improving the existing evaporative misting systems in sow farms and guiding the operating regulation of the proposed system.