Study Of Solar Thermal Numerical Model And Performance Analysis For The Photovoltaic Greenhouse

The photovoltaic module has changed the solar and thermal environment in greenhouse,which will have a negative impact on the growth of greenhouse crops.However,a reasonable photovoltaic panel configuration can improve the uniformity of solar radiation in the greenhouse.In order to analyze the influence of PV panels on temperature and solar radiation distribution in the greenhouse and to improve the economic benefit,it is very important to study the arrangement of PV panels.This paper studied the distribution of temperature and solar radiation environment in different greenhouse panels,and the main research work and achievements are as follows:Firstly,a thermal model based on CFD of the Venlo type photovoltaic greenhouse was presented to analyze the thermal environment of greenhouse.And the computational domain,basic control equation,turbulent model and radiation model were selected for CFD model.In addition,a crop porous media model was added to the simulation.Secondly,a outside solar radiation model was proposed to analyze the solar radiation intensity of the inclined surface of the PV panel,and the relationship between solar elevation angle and glass transmittance at the top of greenhouse was studied.Because of the complexity of the internal structure of the photovoltaic greenhouse and the inside solar radiation is difficult to be analyzed,an incident solar radiation model based on Daysim was presented to analyze the annual solar radiation environment in the photovoltaic greenhouse.Then,in order to verify the reliability of greenhouse model,the environmental parameters in the greenhouse were measured in field test.The simulation results were compared with the measured values,and the reliability and accuracy of the established greenhouse model were verified.Finally,three different PV panel layouts were designed to study the environment performance of PV greenhouse under different arrangement methods,including straight-line arrangement(scheme A),crisscross arrangement(scheme B)and check-board arrangement(scheme C).The photovoltaic panel heat transfer model is proposed,and the influence of the PV panel on the temperature field distribution in the greenhouse is analyzed.The solar radiation uniformity,temperature field distribution,greenhouse energy consumption and power generation capacity were used as the evaluation criteria to analyze the performance of the three PV panel arrangements.According to the calculation analysis,the straight-line arrangement is superior to the other two schemes in terms of solar radiation,temperature field uniformity and power generation,and its energy consumption requirement is lower.The results show that the straight-line arrangement scheme has the best performance in three methods,and the PV greenhouse physical model proposed in this paper can provide the theoretical basis for the design of photovoltaic greenhouse.