Objective Despite the global transition toward a green and low-carbon energy mix, fossil fuels such as oil and natural gas are expected to remain dominant in primary energy consumption for decades. As key nodes in pipeline transportation systems, oil and gas stations are vulnerable to leaks that can trigger cascading accidents such as fires and explosions. This study aims to investigate the deflagration characteristics of natural gas at a representative station through numerical simulations and evaluate the accident consequences, providing a theoretical basis for risk prevention and control.

Method A numerical model of gas deflagration at the station was established, in which the turbulent combustion process was described based on the eddy dissipation model (EDM). Accident evaluation criteria were set based on damage thresholds for overpressure, thermal radiation, and high temperature. Simulations were then conducted to investigate the deflagration evolution of natural gas under different leak pressures and leak heights.

Result The evolution of deflagration overpressure can be divided into four stages: primary overpressure, secondary overpressure, negative pressure stage, and stable stage. The peak overpressure reaches 13.76 kPa, with a corresponding maximum hazard radius of 13.8 m. The thermal radiation flux follows a trend of rapid expansion, contraction, and stabilization during flame development, reaching a peak of 20.04 kW/m² and a maximum hazard radius of 26.2 m. The leakage pressure is positively correlated with the thermal radiation intensity, and the thermal radiation hazard zone at 0.4 MPa is 3.3 times larger than that at 0.2 MPa. As the leak height increases from 0.1 m to 3.0 m, the range affected by thermal radiation first decreases and then increases. The deflagration flame development process can be divided into four stages: initial stage, development stage, peak stage, and stable stage, with a maximum hazard radius of 28.6 m. The leakage pressure is positively correlated with the volume of the high-temperature flames. At a leak height of 0.1 m, the high-temperature region inside the station expands significantly.

Conclusion The development process and propagation laws of overpressure, thermal radiation, and high temperature generated by natural gas deflagration were analyzed. Based on injury criteria, the consequences of deflagration accidents were evaluated, and the maximum hazard radii were determined. In addition, the effects of varying leak pressure and leak height on the distribution patterns of thermal radiation and high temperature generated by deflagration, as well as on the critical hazard zone and its volume, were investigated, providing a theoretical basis for the risk quantification and prevention of deflagration accidents in oil and gas stations.