Experimental Investigation of Thermal Performance for Innovative Spiral Solar Collector

Abstract

This work studies the thermal performance of a novel Spiral Solar Collector SSC experimentally with a mass flow rate ranged from 0.078 to 0.025 kg/s in an open system. A spiral-shaped tube of 13.5 m length, 0.01434 m diameter. The spiral shape is formed from six turns with an 11 cm gap distance between each spiral turn that is attached to an absorber plate. A new black paint mixed with a red sand powder is used to paint the mild steel absorber plate. The experiments are carried out in Al Ramadi city-Iraq under clear weather conditions during January and March 2022. Under different mass flow rates, two fluid flow cases are tested in the experiments; open system and close system cases. The proposed SSC represents a new alternative design that has a noticeable effect on thermal efficiency and outlet temperature. The results showed that there is an increase in the fluid outlet temperature with decreasing the mass flow rate. The difference between the experimental and theoretical results for the maximum value of the temperature difference is (17 K), which gave (6%) percentage error. It is found that the maximum temperature difference was 15 K in the open system case for a flow rate of 0.025 kg/s. According to the current findings, the thermal efficiency has increased up to 17% compared with other SSC and 27% related to conventional flat plate collectors.