Study On Solar Refrigeration System For Low-temperature Grain Storage

Global population growth and climate warming make the grain shortages becomingincreasingly prominent. Countries are exploring how to improve the food production andensure the security of grain storage. The low-temperature grain storage is an effective methodto reduce the loss of storage grain and to ensure the security of grain storage. Most of thelow-temperature grain storage implying mechanical refrigeration in current, but it consumesenergy intensive and operating costs expensive. While refrigeration drove by solar and otherclean energy is pollution-free and of low running costs, thus it become a new method oflow-temperature grain storage.This paper studied solar refrigeration system for food low-temperature storage. Thepaper took silos as the example and established an equation of the thermal conductivity of thegrain mass, as well as the thermal conductivity boundary and initial conditions. It solved thethermal conductivity problem of grain bulk by MATLAB PDE Toolbox, thus it obtained avisual map of distribution of grain temperature within the grain silos, it studied thetemperature distribution law of the grain bulk within the granary as follows; Then this papercalculates the required cooling capacity of low temperature grain storage, especially targetedcooling the granary upper space. The solution to low-temperature grain storage based on solarphotovoltaic proposed. The total power of solar cells according to the refrigerating capacitythe system was determined, the number of solar panels was matched; the number of theelectronic refrigeration piece according to the efficiency of semiconductor refrigeration wascalculated, then the capacity of the battery was determined, completion of the matchingcalculations of the parameters of solar photovoltaic battery, the battery of semiconductorrefrigeration. On the basis of these, the total structure of solar refrigeration system wasdesigned, using solar cells to generate electricity, then stored it in the battery. We adopted theATmega8single chip microcomputer to control the storage battery charging and discharging,according to the set of temperature control of semiconductor refrigeration of open, reach theset low temperature storage temperature. In order to ensure the charging efficiency andservice life of the battery, using PWM pulse modulation to achieve rapid and efficient batterycharging. on the basis of the hardware designing of refrigeration controller, using C language to write the control program, realizing the function of signal acquisition, function of controland protection of charging and discharging of the battery, as well as function of control andprotection the work of semiconductor refrigeration.