Identification of design parameters in a solar collector using inverse heat transfer analysis

• In solar collector, temperature is compared for isothermal and convective boundary.
• Inverse problem is solved for estimating unknowns satisfying a given temperature.
• Binary-coded GA is used to predict unknowns (locations, material and heat loss).
• Many combinations of unknowns exist for satisfying a given temperature field.

The present study aims at identifying different materials as well as the feasible locations, where a particular temperature field can be attained using a flat-plate solar collector. The predictions were based upon the values of thermal conductivity (k) and incident solar heat flux (S), which have been simultaneously estimated along with the associated heat loss coefficient (Ul). A binary-coded genetic algorithm is used to fulfill the objective. The study has been carried out by considering two different heat transfer models involving Fourier and non-Fourier heat conduction. The temperature fields for both Fourier and non-Fourier heat conduction models have been calculated using the finite difference method by assuming a convective boundary condition at the location of the fluid-carrying tube attached to the absorber plate. Further, a comparison has also been made between the temperature fields obtained using the convective boundary condition with those obtained using the isothermal boundary condition. The comparison reveals that the temperature field is highly sensitive to the type of boundary condition. In addition to this, the temperature field has been studied for the effects of Fourier number and the thermo-geometric parameter. This study exhibits that the estimated parameters (Ul, S and k) lie in the ranges from 2 to 3 W/(m2 K), from 490 to 635 W/m2 and from 225 to 280 W/(m K), respectively, which further emphasizes the practical utility to identify feasible materials for the absorber plate and to identify possible locations, where a given temperature field can be attained. The present study is proposed to be very useful in identifying different locations, absorber plate materials along with associated heat losses which will satisfy a given temperature field in the solar collector.