Air heater efficiency of solar drying plant for agricultural products

This article presents the results of experimental studies of the main thermal characteristics of a solar collector, a heated air duct of an indirect type solar drying plant for agricultural products. The results of temperature measurement at the lower, middle and upper parts of the solar collector, at the entrance and output of the air heater at different solar radiation intensities during the day in different periods of the month in the city of Tashkent are given. The results of the calculation of the volume air flow through the air heater, the specific heat capacity of the solar collector on the basis of the profiled aluminum sheet, the specific heat capacity of the air heater and the heat flow of the air heater at different cold air inlet speeds and the intensity of solar radiation during the day, as well as the efficiency of the air heater. It is shown that the installation of the duct on the upper part of the solar collector with high heat capacity ensures natural convection and the achievement of high temperature of the heated air