The Study And The Capability Test Of Solar Greenhouses Thermal Insulation Covering Materials

The facility process of the agriculture of our country has alreadybeen gone through for nearly 50 years, with success and demonstration ofthe sunlight greenhouse production technology of the energy-efficient onlater stage of the eighties, because its remarkable economic benefits andsocial benefit, development speed is very fast, for a long time, sunlightgreenhouse warm - keeping of night such as roofing is it cover with grasscover .with mat with the paper is it realize to coming to depend on mainly.Though the grass is covered .with mat, cattail mat and paper are kept warmand covered the material to play and been very important function in thecourse of development of the sunlight greenhouse by the tradition, etc., butas the sunlight greenhouse is developed in the intensification , scale andhigh-efficient direction, heaviness , waterproof that grass cover . with mat,,quality uneven, use short-lived, mechanized operation difficult, wearingand tearing in membrane destroy day by day conspicuous shortcoming such asbeing serious, develop light quality , waterproof, moderate price , suitablefor factory new-type warm - keeping that produce cover material substitutetraditional grass cover . with mat, cattail mat become trend of times already,paid attention to by such each department as the scientific research of thegreenhouse , production and enterprise, etc.. Through to can use greenhousefor cover industrial screening of raw materials of material with, it formseveral kind the thicknesses the different, structure the different, keepheat conduction coefficient different greenhouse warm, keep performancetest warm, through covering the heat insulator to test to outside that isformed many times, it is the several kind different to keep warm to developgreenhouse of performance compound not keeping warm. It keep ability fine ,ability to resist wind strong , comprehensive good performance warm , cansubstitute grass curtain apply production practices totally. According tothe analysis of result of the test, keep quilt VIIIwarm (whether structure for being high to foam polyethylene + plastic sheeting paper scrap + plastic sheeting + vacuum plate aluminium membrane) All parts can suitable in the whole province with keep warm X(structure for waterproof cloth + high to it foams polyethylene + space wadding to be + high to foam polyethylene + waterproof cloth), and weight is lighter keep quilt IX warm (whether structure for waterproof cloth + space wadding + waterproof cloth), in the middle part of Gansu, east and southern areas can exceed grass ability of keeping warm of curtain too. Cover the heat insulator in the warm - keeping performance test under various kinds of weather conditions new-type outside, because of its pre-pressing structure, the rational matching of various kinds of materials , day wind it in the sleet, demonstrate the ability of warm - keeping better than fine day , cloudy day. And the superficial one is waterproof, reduce the material whole heat-conduction , the main reason that guarantee it keeps performance warm.In keep research that performance improve warm to grass curtain , should select structure dense , thickness heavy grass curtain for use in production, can obviously increase the warm - keeping performance of the greenhouse , especially should notice in the cold area of the climate the winter protection at night of the greenhouse is cold-proof even more, otherwise cause unnecessary losses , influence peasants' economic benefits.Because single layers of grass curtain keep ability warm to be limited, keep performance warm to be unstable , test in grass covering color bar cloth or other plastic membrane with at the curtain, can improve and keep ability 1 warm . 54, heavy area use in rainfall, sleet it can prevent grass curtain from soak also, make the grass curtain keep keeping performance warm. Put on high to foam polyethylene under the curtain in grass , can improve grass curtain keep ability 2 warm. 03, high to foam polyethylene itself have kind warm - keeping person who insulate against heat very , reduce convection and is it dispel the heat to conduct, having increased the result of keeping warm, but the rain-proof function on the grass curtain is not big, use the result of keeping warm to be obvious in the area where the little , external temperature of rainfall is low.