Experimental analysis of the effect of turbulators produced of different materials on heat gain

The rapid advancement and development of technology in recent times have led to increasing importance of the energy sector. The production and efficient utilization of energy have become critically important considering the pressures on fossil fuels and other resources. The geographical distribution of energy sources and instability factors in these regions have further highlighted the significance of energy production and efficient usage. Rising energy costs have prompted people to turn to alternative energy generation methods and seek improvements in energy efficiency. Systems such as steam and hot water boilers used in industries and residential buildings incur significant energy losses through the expulsion of high-temperature flue gases into the atmosphere. Heat exchangers and heat transfer devices are extensively employed in heating, cooling, and power generation systems to facilitate heat transfer. These heat exchangers include types that enable direct or indirect contact with fluids such as water, air, and gases. Research is currently being conducted on various turbulator methods to enhance the efficiency of heat exchangers. Turbulators facilitate the recovery of energy expelled through flue gases and transfer it back to the boiler water. They increase turbulence in the flue gases passing through the smoke tubes, reduce their flow velocity, and increase the surface area for heat transfer, thus enabling the transfer of heat carried by the flue gases to the boiler water. Turbulators are manufactured using various materials like copper, aluminum, galvanized steel, and are designed with different angles depending on their intended applications. In this study, to enhance the efficiency of heat transfer, sheets and spiral plates made from different materials were placed inside copper tubes. The system utilized steam and air as the working fluids. In the experimental setup, the heated water was held in a lower tank and sent as steam through the tubes to the turbulator located in the upper part. A fan was employed in the experimental system to adjust the air flow rate. Experiments were conducted with both turbulated and plain tubes. Calculations performed for galvanized sheets yielded the highest efficiency of 23% at a flow velocity of 2,5 m/s. For galvanized spiral plates, the highest efficiency of 27% was obtained at the same flow velocity. When stainless steel sheets were used, the highest efficiency of 22% was determined at a flow velocity of 3,9 m/s. Similarly, using stainless steel spiral plates resulted in the highest efficiency of 22% at a flow velocity of 3,9 m/s.