CFD Simulation of Heating Process of Greenhouse Irrigation Water in Wintering Period

Abstract

Abstract. In order to solve the problem of low greenhouse irrigation water temperature during the wintering period, the heating process of irrigation water in heating reservoir was investigated under the combined effect of air heat and soil heat with solar greenhouse in Xinyi Town, Lishi District, Shanxi Province as the carrier using three-dimensional non-steady-state methods in computational fluid dynamics (CFD). A dynamic computational model was established to predict the heating process of irrigation water. The measured data were used to reveal the dynamic hexahedron boundary conditions of the heating reservoir in the greenhouse. The simulation results of computation model were validated, and the errors and causes were analyzed. It was shown that the simulated heating process of irrigation water was consistent with the measured data under the influence of changes in boundary conditions, with an average relative error <5.46% and the maximum absolute error of <1.64°C; the correlation coefficient between the simulation values and measured values was greater than 0.96, indicating that CFD simulation of heating process of irrigation water is feasible. Keywords: Agricultural engineering, CFD simulation, Greenhouse, Irrigation water temperature, Solar greenhouse heating reservoir, Three-dimensional non-steady-state, Wintering period.