Abstract: In order to analyze the fire resistance performance of the fire stopping system in UHVDC converter Station, key areas of fire stopping system from two converter stations (Model 1, 2) were selected. Under the hydrocarbon (HC) temperature rise curve condition, the heat transfer process of the fire stopping systems was simulated using ANSYS software. Key thermodynamic parameters including temperature fields, heat flux, and temperature gradients were analyzed. The temperature rise characteristics were further investigated through fire resistance tests and one-dimensional heat conduction model. The results demonstrate: Maximum heat flux density occurs at square steel (stud) locations due to their high thermal conductivity and conduction efficiency. The temperature at measurement point c1 on the backfire surface of Model 1 exceeds 180 ℃, failing to meet fire resistance rating requirements for fire stopping systems. Temperature rise rates at measurement points f1 and f2 are 0.047 1 ℃/s and 0.015 9 ℃/s respectively. Temperature values calculated using the one-dimensional heat conduction model are lower than actual measurements from fire tests. The results indicate that the thermal insulation performance of Model 2 is superior to that of Model 1.

Key words: fire stopping system, fire resistance rating, conduction of heat, HC temperature rise curve, ANSYS