Dynamic Performance Testing And Analysis Of Greenhouse Heat Preservation Quilt In XinJiang

In the recent years, greenhouse industry has been grown up rapidly in Xinjiang.Solar greenhouses is the main form of agricultural development. Greenhouse with large conservatory roof,Even saving heat with the heat preservation quilt through the night there are still about 60% -80% of the heat loss through the greenhouse roof.Climate in Xinjiang has its own peculiarities,such as, scorching ultraviolet radiation, low temperature in winter, large temperature difference between day and night, far-flung rainy and snowy days,strong sandstorm. Currently the Greenhouse in gobi with out the heat preservation quilt ,about 60% -80% thermal energy of the heat is lost through the roof Of the greenhouse.In summary,nighttime the heat preservation quilt is an important measure in greenhouse insulation,but the heat preservation quilt only have 2 to 3 years service life in gobi greenhouse.Therefore,the research on performance and dynamic performance and its change factors, trends of greenhouse in Xinjiang, has a very important practical significance meaningful, for reducing greenhouse heat loss and extend the life of the heat preservation quilt, finding a more suitable covering materials for desert insulation.In this paper, Xinjiang desert environment greenhouse heat preservation quilt performance and dynamic changes, is part of the contents of the National Natural Science Foundation of China, "Active and passive solar heat storage walls and Thermal Performance Evaluation Method of heat preservation quilt of greenhouse in Xinjiang desert insulation.To research the dynamic change of heat preservation quilt performance in the natural use, we needs to analysis 1 to 3 years performance parameters of the heat preservation quilt used in natural environment. Since this study start time is short,obtaining patterns with comparable insulation was somewhat difficult.Therefore, this paper divided the studies the performance of the insulation into two parts. For one,study on performance changes in the natural environment.For another, Take comparative study on the performance of each material of heat preservation quilt by studying the the reason for the performance change. Specific studies are as follows.Chapter one,Summarizes the research status of domestic and foreign research of heat preservation quilt,and proposed the research methods and plans.of this paper.Chapter two,on the basis of heat transfer theory,combined with heat insulation characteristics of heat preservation quilt and Greenhouse.This paper set up a heat transfer model of heat preservation quilts.And then use this method,gives the the main factor in the insulation effect of heat preservation quilt.they are:the way of heat preservation quilt’s suture,the thermal conductivity of the insulation core,the gap between the layers.Chapter three,from the perspective of material science,this paper has discussed the reasons that make the dynamic changing of sunlight greenhouse heat preservation quilt.that is,Surface material has become aging and Loss of the protective effect of the core material by solar radiation, temperature, moisture and other factors in the long time in Gobi under the special environment,and then cause water to enter the core material,and lost its insulation effect.Chapter four and Chapter five,According to the factors affecting the heart preservation quilt insulation performance and caused by the heat preservation quilt performance is dynamic, and is currently testing the heart preservation quilt is analyzed the performance of the experimental method.Combined with the actual conditions of the laboratory, the way of obtaining samples, this paper gives detailed test program and the heart preservation quilt is tensile properties, anti permeability of outer material, the material of the core layer, the thermal conductivity of the heart preservation quilt is the heat transfer coefficient, tensile properties, impermeability performance test.Chapter six,this paper analyzes the results of test.After tested the thermal insulation properties of blankets, hollow cotton, wool carpets,we found the insulation properties of the core layer are reduced with the rise of demons and water content decreased.The tensile properties are reduced with the increase of the number of drops reel and using time.In addition,we also tested the thermal insulation properties of the integral heart preservation quilt, used one year in the nature in Xingjiang.Thermal insulation properties fell 25.7%, which the surface and core, decreased respectively 10.64% andlO.7%, The inner layer of the material fell 1.82 percent.1.82%.the elongation at break of integral heart preservation quilt decreased 63.1% , the surface material fell 55.6% ,the inner layer fell 23.1%.At last,Summing up the above results,point out that the service life of heat preservation quilt mainly related with the anti-aging properties of the surface material.the Tensile Properties of heat preservation quilt mainly related with the surface material and the inner layer.On selected layers of the heat preservation quilt in Xinjiang,we should select the suface material with good anti-aging properties and high tensile Strength. This paper also gaven the analyze comments of specific materials.