FINITE TIME THERMAL ANALYSIS OF GROUND INTEGRATED-COLLECTOR-STORAGE SOLAR WATER HEATER WITH TRANSPARENT INSULATION COVER

摘要

A transparent honeycomb insulated ground integrated-collector-storage system has been investigated for the engineering design and solar thermal performance. The system consists of a network of pipes embedded in a concrete slab whose surface is blackened and covered with transparent insulation materials (TIM) and the bottom is insulated by the ground. Heat may be retrieved by the flow of fluid through the pipe. A simulation model has been developed, it involves the solution of the two-dimensional transient heat conduction equation using an explicit finite-difference scheme. Computa- tional results have been used to determine the effect of such governing parameters as depth as well as pitch of the pipe network and collector material on the thermal Performance of the system. The pipe network depth of l0 cm and the TIM cover made of 5 cm compounded honeycomb seem suitable for the proposed system. Solar gain (solar collection efficiency of 30-- 50/100 corresponding to collection temperature of 40-- 60 deg C) and the diurnal heat storage characteristics of the system are found to be of the right order of magnitude for solar water heating applications.