Abstract:

We developed a new design of an air solar collector made in the form of an inseparable power unit, which includes a frame with heat-insulated walls, single glazing and a selective surface on its bottom. We defined a number of generalizing dependences for the determination of thermal efficiency of an air solar collector, namely, an influence of the mass air flow qa on a temperature difference of the heat-transfer agent to and insulation E, on heat productivity q and the efficiency η of the solar collector. Based on the experimental data, we obtained linear regression dependencies of the average daily ambient temperature teat on energy illumination E and the average temperature of the heat-transfer agent carrier taat of the average daily ambient temperature teat. We verified the adequacy of the results of theoretical and experimental studies. We established that we achieve the maximum values of the efficiency of the solar collector η ‒ from 65 to 80.6 % at a temperature of the outlet flow of the heat-transfer agent to from 30 to 60 °C and mass air flow, qa from 170 to 190 m3/h. We determined that an increase in the level of insulation E from 100 to 1,000 W/m2 makes it possible to increase heating productivity of the collector q from 320 to 1,260 W and the temperature of the heat-transfer agent at the collector outlet to from 10 to 60 °C. We can use the obtained results in development and improvement of technical means for drying fruits, for improvement of technological and energy efficiency of the process. Author Biographies Vitaliy Boyarchuk, Lviv National Agrarian University Volodymyra Velykoho str., 1, Dublyany, Ukraine, 80381 PhD, Professor Department of Energy

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