Exergy analysis of the operation of a solar dryer

The study considers the exergy analysis of rational ways to use and store thermal energy in a solar dryer in order to increase the exergy efficiency of the technological process of fruit drying at individual farms. We analyzed the application of solar energy for the technological process of fruit drying in individual farms based on an exergy analysis of a solar dryer operation. We carried out full-time tests of a solar dryer at the latitude of the location of Rivne oblast (Ukraine), which has an average annual solar power of 3.41 kW·h/m 2 per day. Therefore, this makes it possible to obtain from 74.8 to 123.1 MJ of solar energy per day from 1 m 2 of an air collector area. We improved the procedure of an exergy analysis of operation of a solar dryer, which is based on the simplified mechanism of calculation of an exergy balance of a plant depending on physical parameters of the environment relative specific territory of a farm. The performed complex of calculation-quantitative studies confirmed the possibility of significant intensification of fruit drying process in a solar dryer. We established that heat losses during fruit drying in a solar dryer make up 3...3.7 MJ/kg, and the degree of intensification increases by 3.3...12 times. The exergy efficiency of a solar dryer without the use of a thermal battery is 87.6 %; with it – 89.8 % with the use of a thermal battery. The exergy efficiency of a solar dryer increases by 1.02 times. We achieved such results by using a flat mirror concentrator and a thermal battery in a solar dryer. An applied aspect of using the results obtained is the possibility to increase the energy efficiency of fruit drying process based on exergy express-analysis of the efficiency of a solar dryer. It will reduce the cost of energy resources by using solar energy. It creates a prerequisite for the transfer of technological solutions for justification of exergy balances for various characteristics of fruit drying process in a solar dryer.