APPLICATION OF ENERGY-EFFICIENT ICE-ACCURACKING TECHNOLOGIES IN AIR CONDITIONING SYSTEMS

• Дата: 2025
• Автори: Korbut , V., Rybachov , S.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: Institute of Renewable Energy National Academy of Sciences of Ukraine 2025
• Теми: renewable energy sources; solar radiation energy; natural circulation; solar water heater; flow rate; temperature head.
• Онлайн доступ: https://ve.org.ua/index.php/journal/article/view/566
• Назва журналу: Vidnovluvana energetika

An analytical model for the flow of heat carrier in natural-circulation (thermosiphon) solar water heaters is presented. A differential equation for the flow velocity   is derived, accounting for the gravitational driving head due to density differences between hot and cold fluid and for hydraulic losses (friction and local resistances). The time evolution of the temperature difference   between the heated and cold sections of the loop is characterized and described by a generalized gamma-like function with a controllable peak. Using the derived model, the unsteady velocity and volumetric flow rate of the circulating fluid are simulated numerically. Graphs of   are provided, as well as a surface   illustrating the relationship between flow rate, time, and temperature head. The conclusions highlight the scientific novelty of the results, their practical significance for designing efficient thermosyphon solar heaters, and directions for further research, including accounting for nonlinear fluid properties and system optimization.