Experimental study of the thermal performance of spiral flow solar water heating system

Abstract

The Iraqi population experiences a scarcity of hot water during the winter season. In this paper, the utilization of solar collectors emerges as a viable alternative to conventional sources of energy, such as electricity and fuel, and Solar Water Heating Systems (SWHS) are widely regarded as a viable alternative for water heating, particularly in regions where the cost of fuel and electricity is high or where access to these resources is limited. The analysis of the collector’s performance was conducted by considering the variables of solar irradiance, wind speed, and mass flow rate. A maximum overall heat loss coefficient was 5.36 W/m² °C and a maximum useful heat gain was 505 W. The study revealed a positive correlation between solar irradiance, water mass flow rate, and the performance of the collector. Conversely, a negative relationship was observed between wind speed and the collector’s performance. The experiment revealed that the spiral collector achieved a maximum efficiency of 66.3%, with a flow rate of 0.042 kg/s. Additionally, the spiral collector demonstrated a maximum increase in water tank temperature of 23.3 °C, at mass flow rates of 0.042 and 0.05 kg/s.

Graphical abstract

Highlights

Evaluating the flow rate influence on the spiral collector.

Comparing the thermal efficiency of a spiral collector with a changing flow rate.

Highlighting the influence of some factors on the spiral collector’s performance, such as wind speed, solar irradiance, and water inlet temperature.

Discussion

The efficacy of governmental subsidies for solar water heating systems, particularly in low-income and developing regions, poses inquiries on the fair and equal availability of long-lasting technology.

The significance of cultural views and customer behavior in the acceptance of solar water heating systems emphasizes the necessity of tackling society's attitudes toward renewable energy technologies.

The influence of domestic manufacturing capabilities and supply chains on the cost efficiency and environmental friendliness of solar water heating systems is still a substantial and unresolved matter.