Thermodynamic analysis of a novel solar water heating system during low sun radiation in Iran

Document Type: Research Paper


1 Department of Mechanical Engineering, Faculty of Engineering, Urmia University of Technology,Urmia, Iran

2 Department of Business Management, National Iranian Oil Refining & Distribution Company, Tehran, Iran


This paper reports a plenary thermodynamic model of a novel solar system for water heating in buildings. Energy and exergy analyses are used to characterize the exergy destruction rate in any component and calculate system overall efficiency. The system consists of a solar evaporator, a heat exchanger to produce hot water, and an auxiliary pump. A computer simulation program using EES software is developed to model the solar water heating system. The system provides hot water during the hours of low sun radiation. Thermodynamic analysis involves the designation of effects of heat exchanger pinch point and ambient temperatures on the energetic and exergetic performance of the solar water heating system. The performance parameters computed are exergy destruction, and energetic and exergetic efficiencies. The result showed that the main source of exergy destruction is the solar evaporator. In the solar evaporator, 92.85% of the input exergy was destroyed. The other main source of exergy destruction is the heat exchanger, at 4.15%. The overall energetic and exergetic efficiencies of the solar water heating system were approximately 60.17% and 3.002% respectively.


[1] McCartney W.J., 2011 Ashrae Handbook HVAC Applications (2011). McGraw-Hill.

[2] Iran Renewable Energy and Energy Efficiency Organization Annual report (2010-2017).

[3] Cengel Y. A., Heat Transfer a Practical Approach, 2th Edition (2003): 566.

ISBN: 0072458933 9780072458930 0071151508 9780071151504, Boston: McGraw-Hill.

[4]Sadiq M., Solar Water Heating System for Residential Consumers of Islamabad, Pakistan, A Cost Benefit Analysis, Journal of Cleaner Production (2018) 172: 2443-2453.

[5]Mazarrón F.R., Porras Prieto C. J., García J. L., Benavente R. M., Feasibility of Active Solar Water Heating Systems with Evacuated Tube Collector at Different Operational Water Temperatures, Energy Conversion and Management (2016) 113: 16–26.

[6]Zainine M.A., Mezni T., Dakhlaoui M. A., Guizani A., Energetic Performance and Economic Analysis of a Solar Water Heating System for Different Flow Rates Values, A Case Study, Solar Energy (2017) 147: 164–180.

[7]Allouhi A., Jamil a A., Kousksou T., Rhafiki T. E., Mourad Y., Zeraouli Y.. Solar Domestic Heating Water Systems in Morocco: An Energy Analysis, Energy Conversion and Management (2015) 92: 105–113.

[8]Sadhishkumar S., Balusamy T.. Performance Improvement in Solar Water Heating Systems, A Review, Renewable and Sustainable Energy Reviews (2014) 37: 191–198.

[9]Wang Z., Yang W., A Review on Loop Heat Pipe for Use in Solar Water Heating, Energy and Buildings (2014) 79: 143–154.

[10]Zhang X., Zhao X., Xu J., Yu X., Study of the Heat Transport Capacity of a Novel Gravitational Loop Heat Pipe, International Journal of Low-Carbon Technologies (2013) 8: 210–223.

[11]Duffie J.A., Beckman W.A., Solar Engineering of Thermal Processes, 4th Edition (2013): 202-342

ISBN: 978-0-470-87366-3, New York: Wiley.

[12] Azad E., Assessment of Three Types of Heat Pipe Solar Collectors, Renewable and Sustainable Energy Reviews (2012) 16: 2833– 2838.