| Heilongjiang is located in the northernmost province of China.Besides the short sunshine time,the low temperature also affects the planting and growth of vegetables and fruits.Greenhouse greenhouse,as an agricultural facility to maintain crop growth temperature and prolong crop cultivation cycle,greatly utilizes solar energy to realize vegetable cultivation and supply in northern China.Sunlight greenhouse is widely used because of its simple structure and high efficiency of utilizing solar energy.However,the outdoor temperature in Northeast China is too low and the temperature difference between day and night is too large.The greenhouse with pure sunlight insulation cannot fully meet the needs of modern agricultural planting.The greenhouse improved on the basis of ordinary sunlight greenhouse has been applied.Research on this paper the water curtain temperature regulation and warming greenhouse constructed by Daqing Yulu Agricultural Science and Technology Development Co.,Ltd.Taking the water curtain greenhouse designed by the company as the research object,based on the numerical calculation function of FLUENT software and MATLAB,the temperature field and velocity field in the water curtain greenhouse are simulated by comparing and analyzing,and the temperature data of the water curtain greenhouse and the sunlight greenhouse are numerically simulated to study its advantages in temperature control and temperature maintenance.Specific analysis is as follows:1.By studying the temperature characteristics related to crop growth and the basic model of accumulated temperature,the mathematical model of greenhouse greenhouse in maintaining temperature and affecting crop growth and development was proposed.The effects of water curtain greenhouse and sunlight greenhouse on crop growth and development were studied by using other scholars’ models and self-designed three-base point model.2.By establishing the mathematical model of pure solar greenhouse and water curtain greenhouse,using FLUENT software included in ANSYS 14.0 version system software and GAMBIT modeling software independent of this series of software,the temperature field and velocity field in solar greenhouse and water curtain greenhouse are simulated,and the temperature distribution of the wall section and the middle section in greenhouse are analyzed,and it is found that the water curtain is large.The greenhouse not only has the function of warming up at night,but also is superior to the greenhouse irradiated by pure sunlight in maintaining uniform temperature distribution.3.Establishing the mathematical model of thermal efficiency analysis of water curtain greenhouse based on crop growth and development,using the actual temperature data as input variables,taking the secondary model of crop growth and development based on temperature and the natural index model based on active accumulated temperature as research methods,studying the thermal efficiency of water curtain greenhouse in crop growth and development;and putting forward the concept of equivalent accumulated temperature,setting up water curtain.Quantitative study was conducted on the efficiency of crop growth and development.By using the natural index model to calculate the crop growth rate,it is found that the error of the crop growth rate calculated by the stage accumulated temperature is more than 40% in the actual calculation,and there is a big deviation in the prediction of crop growth. |
PDF Full Text Request