Solar thermal analysis of transparent-honeycomb-insulated ground collector-storage system

This paper presents an analysis of heat transfer processes in a transparent-honeycomb-insulated solar collector made of such low-energy materials as soil/sand/concrete, which also acts as a heat store. The analysis assumes solar intensity and atmospheric temperature as well as the resultant temperature in the ground and concrete/sand region to be periodic. An explicit expression for the heat flux that can be extracted at constant mass flow rate and at constant heat extraction temperature is derived. Numerical computations corresponding to typical months of June, September and December at New Delhi are presented. The solar conversion efficiency of 30-60% corresponding to a collection temperature in the range of 40-70 degrees C is reported. The solar gain and heat storage characteristics of the proposed system are found to be of the right order of magnitude for solar water-heating applications. Copyright (C) 1996 Elsevier Science Ltd.