This study proposed a multi-tube (polyvinyl chloride

PVC) array thermal energy storage structure based on butyl stearate phase change material

aiming to develop a simple and low-cost thermal energy storage device for solar greenhouses. The thermal environment of a greenhouse with a multi-tube array thermal energy storage device was studied through a series of experiments. The results indicated that the heat storage capacity of the device with a black surface was 66.7% higher than that with a white surface under similar irradiation conditions. Compared to devices with diameters of 50 mm and 110 mm

the discharging performance was the best when using a 75 mm PVC pipe containing butyl stearate. Moreover

in contrast to traditional solar greenhouses

the nighttime average temperature of the solar greenhouse with the multi-tube array thermal energy storage device was higher by more than 1.2 ℃

and the in-situ thermal energy storage capacity of the unit with butyl stearate reached 163 kJ/kg (including sensible heat). Therefore

multi-tube array thermal energy storage devices

which are economical

safe

and simple

can be widely applied in solar greenhouses.