An experimental investigation on the efficiency of a Flat-plate solar collector with binary working fluid: A case study of propylene glycol (PG)–water

Abstract

The effect of propylene glycol (PG) concentration variation in propylene glycol–water solution at various mass flow rates (0.0167, 0.0333, 0.05kg/s) on the efficiency of a Flat-plate solar collector was investigated experimentally. The experiments were carried out using 5 different PG concentrations in water including 0%, 25%, 50%, 75%, and 100%. The procedure of ASHRAE standard was applied to test the thermal performance of Flat-plate solar collector. Results indicate that using PG–water at 25% PG concentration in mass flow rate of 0.0167kg/s reduces the efficiency of the Flat-plate solar collector by 15.68%, compared to that at 0% PG (pure water). Increasing PG volume concentration from 25% to 75% enhances the efficiency of the Flat-plate solar collector and increasing volume concentration from 75% to 100% reduces the maximum efficiency of the Flat-plate solar collector by 8.3%.