SOLAR THERMAL-SYSTEMS WITH TRANSPARENT INSULATION

In this paper, theoretical models are formulated to predict the thermal behaviour of various solar systems, viz. shallow solar pond water heater, built-in-storage type solar water heater, isolated non-airconditioned room and cubical collector-cum-storage system, provided with transparent insulation. The transient nature of its performance is represented by the time dependent energy balance equations. These differential equations are solved by a finite difference forward step marching technique. The absorption of solar radiation by the transparent insulation is taken into account by considering the wavelength dependent extinction coefficients for five wavelength regions of the solar spectrum. The numerical simulation of these models for the winter conditions of Delhi shows that the systems with transparent insulation present a better performance than those without transparent insulation. The cubical collector-cum-storage system proves to be one with a good potential for seasonal storage.