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Drying Theoretical And Experimental Study On Green Soybean Seeds With Heat Pump

Posted on:2013-02-26Degree:DoctorType:Dissertation
Country:ChinaCandidate:E L ZhuFull Text:PDF
GTID:1263330392969712Subject:Refrigeration and Cryogenic Engineering
Abstract/Summary:PDF Full Text Request
As a populous country, food security is the key to achieve sustainabledevelopment and national strategy. Drying technology is an important link of seedsprocessing, it is a reliable technology to guarantee reducing food loss, improvingquality and agricultural returns.Traditional drying technology’s characteristic is highenergy consumption and high pollution, in the environment of energy conservationand emissions reduction and sustainable development, it has been increasingly beingrestricted, heat pump drying has some prominent technical advantages in energyconservation and emission reduction, improve quality and controllable operation, sostrengthening theorical research of seeds’ heat pump drying technology has becomean important part of the development of modern drying technology. Combining withinterdisciplinary theories, green soybean seeds’ heat pump technology of the lowtemperature dehydration system has been researched, the brief structure and maincontent as follows:(1) Isotherms and type of green soybean seeds were measured and diterminedthrough static gravimetric method at different temperatures and water activity;parameters of BET much molecular layer absorption theory and goodness-of-fit ofisotherms models were determined by using nonlinear regression method; thethermodynamic parameters including numerical range of net isosteric heat ofadsorption and desorption were calculated by using water activity sorption isostericmodel.(2) The influence law of green soybean seeds’ glass transition temperaturewith moisture content and heating rate were investigated, Tgwere measures bydifferential scanning calorimeter (DSC), mathematical model of Tgwas determined byextrapolation method.(3) Green soybean seeds’ drying characteristics wereresearched using drying test bed, effective diffusion coefficients range and suitabledescripting drying characteristics models were determined; The influence law ofdrying factors on seed germination rate of continuous and tempering dryingtechnology were analysised by saturated D test method, regression models ofgermination rate were gotten; influence law between germination rate and dryingfactors was analyzed by dimension reduction method, optimization drying technologyof green soybeans seeds was gotten by using wheat quarts and general global optimization method, enzyme activity changing law of enzyme defend system wereanalyzed in continuous drying, and energy consumption of tempering drying processwas discussed and numerical solution of energy consumption was gotten. Conclusionsin this paper have provided basis theory for green soybean seeds in heat pump dryingprocess.
Keywords/Search Tags:green soybean seeds, heat pump drying, isotherms, glass transition, tempering, energy consumption
PDF Full Text Request
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