Research On Humidity Difference Dehydration Technology In Solar Drying Chamber

Solar energy is a clean energy, but because of its intermittent, instability, hindering thedevelopment of solar energy applications. In this experiment, chinese cabbage and othervegetables as materials, the air as the drying medium. With fan forced ventilation, the dry airwas introduced into solar drying room. Indoor and outdoor humidity difference fordehydration of vegetables.The four seasons in Lanzhou air temperature and humidity level,dehydration process variation rules and the air temperature and humidity in different seasonswere investigated in this paper.1. The annual solar dehydration workshop warming obviously, and the highest averageatmospheric temperature is24.9℃and the lowest is4.2℃; Indoor average temperature of30.48℃in spring,35.48℃in summer,20.19℃in fall and4.79℃in winter; Averagerelative humidity in hothouse was33.1%in spring,40.52%in summer,44.52%in autumn,42.43%in winter. Under the real load conditions of the drying chamber, the humiditysignificantly greater indoor than outdoor. The difference of air moisture content was2.97g/kg in spring,3.44g/kg in summer,1.23g/kg in autumn and1.4g/kg in winter.2. Chinese cabbage as materials, compared different seasonal dehydration rate and ovendehydration rate. Using the wind turbine whole day, average drying time was30h in spring,28h in summer,72h in autumn and64h in winter. Using the wind turbine12h a day(8:00~20:00), the average drying time was37h in spring,35h in summer,79h in autumn and71h in winter.3. Research at night without solar of air dry capacity, namely wet sent dehydrationeffect. The results show that: the winter of106.3kg dehydration during the day, and thedehydration of29.7kg at night; During the summer of dehydration127.5kg,8.7kg ofdehydration by night.4. Chinese cabbage, parsley, spinach, garlic bolt total dehydration time for3days(thetime of light received24h); Green pepper, red pepper, carrot total dehydration time for4days(reception illumination time32h); Onions always dehydration for6days (receivingillumination time48h). Description of the organizational structure and water content of different vegetables to affect the dehydration rate.5. Different season solar wet sent dehydration dehydration mathematical model:Spring： MR=1.135-0.082×t+0.004×t~2-0.0000686×t~3Summer: MR=1.119-0.083×t+0.003×t~2-0.0000502×t~3Autumn： MR=1.023-0.015×t-0.00000366×t~3Winter： MR=0.996-0.007×t+0.0000022×t~36. For solar wet sent dehydration in cost accounting, compared with hot air drying oven,dryed the same weight materials, the solar energy saving rate for dry wet sent73%-89%. Thecoal consumption for drying150kg chinese cabbages by solar wet sent was5.38kg-13.82kg.