An Experimental Study on the Effect of Closed-Steam Pressure as a Thermal Core on the Combustion Characteristics of Used Oil in a Pool Combustion System

Used oil has the potential to be utilized as an alternative fuel; however, its combustion characteristics must be controlled to ensure flame stability. This study evaluates the effects of closed-system steam pressure, which serves as the thermal core, on flame temperature, thermal core temperature, burning rate, and flame stability in a pool combustion system. We conducted experimental tests at three steam pressure levels (1.0, 1.5, and 2.0 bar), using an initial used-oil mass of 120 g for the burning-rate measurements. Each temperature measurement was performed in triplicate. The results showed that increasing steam pressure increased the average flame temperature from 395.67 °C at 1.0 bar to 416.00 °C at 1.5 bar and 502.67 °C at 2.0 bar. The thermal core temperature also increased from 100.17 °C to 111.80 °C and 129.03 °C, respectively. The burning rate increased from 7.38 to 8.10 and 9.02 g/min, while the combustion time required to burn 120 g of used oil decreased from 16.25 to 14.8 and 13.3 min. Based on observational assessments, flame stability improved from poor at 1.0 bar to stable at 1.5 bar and highly stable at 2.0 bar. However, a loud, jet-like roaring sound was observed at the highest pressure. These findings indicate that a steam pressure of 2.0 bar provided the best performance among the tested conditions in terms of flame temperature, thermal core temperature, and burning rate, although the accompanying noise should be considered in further system optimization. Contribution to Sustainable Development Goals (SDGs):SDG 7: Affordable and Clean EnergySDG 11: Sustainable Cities and CommunitiesSDG 12: Responsible Consumption and Production