The Performance Research On The Wall Structure Of Solar Greenhouse In Gobi Region In Xinjiang

This paper aims at solving the wall structure optimization using local materials in Gobi desert in Xinjiang and takes the wall of solar greenhouse in Xinjiang Gobi region as the main research object.Based on the value of the lower limit of thermal resistance in solar greenhouse and the simulated forecasting software of heat storage capacity in solar greenhouse walls, it carries out the design and calculation of the wall structure in Gobi solar greenhouse, forming the optimal wall combination regimen that is suitable for the solar greenhouse in Gobi region of Xinjiang, and then establishes the optimal modes of material and environment control, promotes the development of solar greenhouse design, construction theory and methods and strengthens capacity for sustainable development in facility agriculture. The main contents include the following parts:(1) Regarding at the unique characteristics of ecology and natural environment in Gobi desert region, this thesis makes a comparison of the wall materials that are suitable for solar greenhouses in Gobi. Collecting and collating the dry bulk density and thermal conductivity of thermal insulation materials as well as the common heat storage materials of greenhouse in Xinjiang, the author aims at provide reliable numerical values for combinatorial computing of the Xinjiang Gobi greenhouse.(2) Aimed at the combination mode of five types of Xinjiang practical multilayer walls with different thickness and materials, greenhouse standard is introduced and referred: the design concept of thermal resistance value of wall materials in JB/T 10286-2001 “solar greenhouse structure” is helpful for five types of highly practical multilayer walls with a total of 403 kinds to make a combination of different thickness and materials; besides, calculate the multilayer composite wall structure which conforms to the outside design temperatures condition that is appropriate to greenhouses in Xinjiang through combination of various thickness and materials.(3) Based on RGWSQCR simulation software for the thermal insulation performance of solar greenhouse wall developed and designed by the Key Laboratory of the Department of Facility Agriculture and Agricultural Engineering affiliated to China Agricultural University, this paper proposes that greenhouses consisting of seven kinds of different combinations of wall structure suit production-type greenhouses in Kizilsu Kirghiz Autonomous Prefecture in Xinjiang and simulates the average heat release per unit area and the accumulative total of heat release. Through simulating the diurnal variation of the indoor environment and the regularity of heat release of greenhouse walls at night with time, the difference of insulation performance among seven types of representative structural walls has been contrasted.(4) As for these Gobi greenhouses built by four kinds of different wall structures, testing the minimum temperature, maximum temperature, average value and the law of consecutive diurnal change and comparing the differences in the impacts of different walls on greenhouse microclimate, the greenhouse wall structure scheme of greenhouse thermal performance has thus been obtained.Through combinational computation, simulation test as well as factual data analysis for the wall structure of solar greenhouse in Gobi desert, it has been concluded that: under the conditions that Xinjiang greenhouse outdoor design temperature is-5 ?~-32 ?, there are 320 kinds of combining methods for multilayer composite wall in total which meet the requirement that these combinations be greater than the lower limit of thermal resistance; Seven kinds of different combinations of wall structure suit production-type greenhouses in Kizilsu Kirghiz Autonomous Prefecture in Xinjiang have been put forward in this paper and through software simulation, greenhouses which are featured by a better performance are: cyclopean concrete revetment of 0.2 m + Gobi desert and soil's piling up of 1.8m>dead wall of Gobi desert of 2 m>soil wall of thick Gobi desert of 1.5 m + cob of 10cm; apart from this, through the real-time supervision towards the greenhouse built by four kinds of building wall, the optimal wall structure of thermal performance that suitable for greenhouses in Kezhou, Xinjiang has been obtained which is Gobi desert+revetment structure of cyclopean concrete.