Numerical and experimental performance evaluation of a polymer direct solar irradiation collector

Abstract

With the objective of reducing costs and proliferating use, a special Direct Solar Irradiation Collector (DSIC) solar water heater was developed. To produce a commercially feasible product, a full research and development program was conducted that included several generations of prototypes and a range of design criteria such as material selection, manufacturing processes, economics, and materials availability. The result was a Parallel Plate type collector made out of polymers which is designed for temperate weather and low pressure household-use. It is able to achieve similar efficiencies and performance than commercial water heaters while cutting its cost by half. The present study introduces the concept and includes numerical and experimental results made on a scaled prototype. The numerical analysis compares the pressure-drop across 3 collectors. The pressure-drop is better by almost a factor of 4 when comparing the DSIC and a Parallel Tubes type collector. Performance tests were conducted outdoors to measure the temperature and solar irradiation as a function of time. Different ratios between collection area and water volume were tested. Temperature was measured simultaneously at different locations to observe the thermal gradient along the collector and water tank. Maximum temperature of 95°C and max efficiencies on the range of 84-92% were achieved by the DSIC collector.