Optimization of a Heating System Using the Hot Water Radiator Pipe of a Large-scale Greenhouse

Abstract

A hot water radiator pipe facilitates excellent temperature uniformity in a greenhouse environment and is commonly used during winter in large-scale greenhouses in combination with sunlight. The hot water that flows inside the radiator pipe is used for temperature control, and heating is linked to the environment inside and outside of the greenhouse.In this study, the effect of hot water radiator pipe heating in a large-scale greenhouse was evaluated based on actual measurements and numerical fluid analysis.Based on the experimental results, it was determined that the temperature of the radiator pipe decreased by a maximum of 5.9 ℃. In addition, a temperature variation of 3.5 ℃ occurred in the greenhouse. An estimation equation for the surface temperature of the radiator pipe was derived using experimental measurements, and it was used to set the heat radiation conditions for the numerical fluid analysis. To improve temperature uniformity, it was determined that the temperature unevenness in the greenhouse could be reduced by changing the position of the inlet that connects the boiler to the radiator pipe.