Thermal Analysis of the Effect of Absorber Plate Geometric Parameters on the Dynamic of an Indirect Type Solar Dryer

Abstract

This paper studies the effects of the absorber plate geometry on the thermal performance of an indirect solar dryer considering temperature dependent thermal conductivity and heat transfer coefficients. The main goal was to explore the effects of the absorbers confined air as well as the absorber plate thicknesses and to provide more realistic characterizations of the thermal dynamic of an indirect solar dryer. The heat transfer process is described using highly nonlinear partial differential equations. The mathematical model accounts the contribution of the upper soil surface temperature calculated using the boundary layer similarity theory. The established mathematical equations describing heat transfer in the solar drying system are solved numerically using a developed MATLAB program. The investigations of heat transfer of the proposed model reveal excellent agreement of prediction responses with the experimental results from the literature. Mathematical model of indirect solar drying prototype developed with double absorber plates separated with a confined air layer operates more effectively with a thermal efficiency greater than 6% compared to the model without confined air configuration. The numerical experiments also show the non-negligible effects of the absorber plate thickness on the thermal dynamic of an indirect solar dryer.

An artificial neural network modeling of solar drying of mint: Energy, exergy, and drying kinetics

“…A net value is produced by a processing element by combining the xj input information that is obtained from the wij weights to which they are linked "Eq. ( 19)" computes the net value of the i. processing element (19) Each processing element performs the second process to find the output value by passing its net value through an α (.) activation function.…”

“…Increases in the irreversibilities of thermal processes can destroy the exergy, thus to increase the exergy of a dryer, the irreversibilities need to be decreased [18]. Researchers examined how the design of the absorber plate affects an indirect solar dryer's thermal performance while taking temperature dependence into account [19].The exergy analysis is used to find the origins of inefficiency, to identify the quality of energy utilization, and to provide information for optimization of drying conditions to reduce the environmental problems which produce by the dryers [20]. Researchers aimed to increase system efficiency by using energy and exergy analysis in drying food products.…”