Evaluation of thermal performance through development of an unglazed transpired collector control system in experimental pig barns

Abstract

The application of unglazed transpired collectors (UTCs) in livestock barns is a good solution for reducing not only the energy lost though ventilation and structures but also the electricity consumed by heat lamps. However, a control system and operating strategies need to be developed for the application of UTC systems in pig barns in order to maintain room temperature and increase the efficiency of the UTC systems. Therefore, this research focused on analyzing the control signals and temperatures of pig barns that depended on UTC control systems, thermal performance of the UTC, and electricity consumption through a field test. A UTC fan was operated for a daily average of 7h with the application of a UTC control system and the possibility of reducing the electricity consumption was confirmed. Through the UTC control system, the effect of a temperature rise was confirmed, with an average rise of up to 27.6°C compared with the ambient temperature. A correlation model was verified between solar radiation and collector surface temperature: the linear model was R2=0.93, whereas the nonlinear model was R2=0.92 of solar radiation with a temperature rise (ΔT). It was verified that the heat exchange effectiveness was distributed roughly between 0.5 and 0.7, and tended to decrease as the amount of solar radiation increased (R2=0.49). The efficiency was distributed roughly between 20% and 60%, and the efficiency equation was presented through the inverse relation with the amount of solar radiation (R2=0.77). It was confirmed that it is possible to reduce electricity consumption by approximately 30.8% through the application of a UTC control system.