Design And Simulation Test Of The Over-the-top Rolling System For External Insulation Of Arch Greenhouse

Covering insulation is an important insulation measure to reduce heat loss through the cover at night in a greenhouse.Solar greenhouses and plastic greenhouses commonly used in production can meet the production in cold northern regions without heating or little heating in winter because of the roof arched structure that can be covered with insulation on the outside.However,the existing insulation covering method cannot achieve the over rolling the top of the arch,and the rolled insulation is placed on the top causing additional load on the roof and indoor shading.Therefore,this study mainly completes the arched greenhouse external insulation over the top rolling system(Over-the-top Rolling System,ORS)design and verification operation.First,the three-dimensional model of the insulation roller,the rope roller and the coiling rod was established by SolidWorks,and ANASYS was introduced to assist in the deformation analysis to verify the reasonableness of the diameter and wall thickness specifications of the selected rod.Then,the chain transmission system was performed by SolidWorks and ADAMS modeling and simulation analysis to verify whether the specifications of each component of the selected chain transmission system can meet the transmission needs of the over-the-top rolling system;then,ADAMS is used to model the two flexible bodies of insulation and rope.Analyze the tension of the insulation and rope and,the maximum winding radius of the insulation,and choose the appropriate insulation thickness and rope diameter.Based on this,the working way of the over-the-top rolling system and the main component parameters and parameter selection methods are determined.According to the formula calculation and the simulation by SolidWorks,ANASYS and ADAMS,design and calculate the selection of ORS components,and establish the ORS on the 1:20 scale greenhouse model to verify its operation.For the test,a thermal insulation insulation with a fluffy thickness of 10 mm and a compacted thickness of 2 mm,a stainless steel tube with a diameter of 25 mm and a wall thickness of 1.5 mm,a 2 mm diameter steel wire rope,a number of 06B chain and the matching 29-tooth sprocket,a 400 W motor were selected,and designed a tower wheel with 2 mm pitch,22 turns,2 mm width,1 mm depth,and the drawing angle of 30°.The over-the-top rolling system was installed on a miniature greenhouse and run.The test results show as follows:1)The over-the-top rolling system adopts the working way of coiling cover and rolling discover the insulation to realize the integrated coverage of the insulation over the top,the working mothod is feasible,and improves the insulation airtight which will improve the overall insulation;2)Compared to the way in which the insulation is placed on the top,the over-the-top rolling system can reduce the arch load by 42 N/m~2 when placed the insulation on the gutter,and reduce the 33%indoor shading caused by the insulation placed on the top of the roof.The over-the-top rolling system can improve the ability of indoor lighting,reduce the diameter and wall thickness of the arch,which is conducive to the development of lighter and simplified skeletons,and reduces construction costs;3)The average maximum diameter after the insulation is rolled up is 116.2 mm,which is less than the width of the model greenhouse gutter(320 mm)and does not cause additional shading;the maximum tension of the traction rope is 736.119 N,which is less than the selected wire rope(φ=2 mm)minimum breaking force of 2 296 N;the maximum working power of the over-the-top rolling system is 384 W,the maximum measurement value of the torque sensor is 8 849.138 N·m,the rated power of the selected motor is 400 W,and the maximum allowable torque is 6×10~5 N?m.The thickness of the selected insulation,the diameter of the steel wire rope,the motor power and the maximum allowable torque are reasonable,and the selection method of the main components is determined;4)The speed of the insulation and the rope is synchronized during the entire working process of the insulation cover and discover,the relationship between the size of the tower wheel and the thickness and width of the insulation,the diameter of the rope and theinsulation roller are determined,and the design method of the tower wheel is established.5)The chain drive system rotates stably at low speed during the entire working process,without any jamming or breakage,indicating that the chain drive system meets the drive requirement of the ORS and the sprocket chain of the selected specification and the tensioner are reasonable,and determineding the method of drive system and the motor through ADAMS simulation.