The feasibility of jet fan-assisted ventilation for temperature control of heating belts on a downward-facing sphere in a scientific facility

¹ School of Mechanical Engineering, Institute of HVAC Engineering, 201804 Tongji University, China
² Key Laboratory of Engineering Structure Performance Evolution and Control, Ministry of Education, 201804 Tongji University, China

^* Corresponding author: weiye@tongji.edu.cn

Abstract

To avoid the deformation of the large-scale scientific facility for neutrinos detection due to temperature changes, the heat generated during the top-down annealing of the inorganic glass panels needs to be released in time to maintain temperature control of 21±1°C in the built-up area. Due to the unique shape and the changing heating sources, a novel ventilation strategy that combines jet fans with general ventilation was proposed to satisfy the special environmental control requirement. A small-scale field experiment was conducted to obtain the CFD methods for simulation. Then, the feasibility of the jet fan-assisted ventilation system was discussed in terms of two thermal control zones based on the distance from the heat source. Besides, the effectiveness of the proposed ventilation design was compared with traditional general ventilation with air-conditioned air supplied from the hall ceiling and directly opposite the heating belt based on the temperature and velocity distribution. The results show that: the area outside the thermal control range under jet fan-induced ventilation was reduced by around 60%, and the maximum temperature fluctuated over time within 0.33°C. These results provide a preliminary insight into the use of jet fan-assisted ductless ventilation to achieve precision local temperature control in a large space.