As key nuclear equipment, once-through steam generator (OTSG) can guarantee the safe operation of nuclear power plants. The accurate calculation of the OTSG’s pressure drop is particularly critical to the design of the nuclear power plant primary circuit. When using CFD to calculate the OTSG’s pressure drop, the inlet pressure, the inlet temperature and the inlet flow rate as input parameters are measured. Measurement errors will cause uncertainty. The uncertainty of these input parameters will be transmitted in the CFD calculation, resulting in the uncertainty of the OTSG’s pressure drop. Therefore, how to analyze the uncertainty of the OTSG’s pressure drop in the CFD calculation process is particularly important.
In this paper, a three-dimensional CFD model of OTSG is established. And the uncertainty of OTSG’s pressure drop is analyzed by polynomial chaos expansions (PCE). This paper mainly quantifies the influence of the uncertainty of boundary conditions and turbulence model parameters on the OTSG’s pressure drop. Therefore, the risk of OTSG operation caused by uncertain factors is reduced. The results show that the uncertainty of the OTSG’s pressure drop due to the boundary conditions is 2842 Pa, and the most influential input parameter is inlet flow rate, which accounts for 96.8%. The uncertainty caused by turbulence model parameters is 202 Pa.