Original Article

Design and flow field characterization of safety valves based on the Laval principle

¹ AVIC Harbin Dongan Engine Co., Ltd., Harbin, Heilongjiang 150066, PR China
² School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150001, PR China
³ Harbin Power Valve Co., Ltd., Harbin Electric Corporation, Harbin, Heilongjiang 150090, PR China
⁴ School of Mechanical and Power Engineering, Harbin University of Science and Technology, Harbin, Heilongjiang 150080, PR China

^* e-mails: 23s108308@stu.hit.edu.cn; 3482235817@qq.com

Received: 11 March 2025
Accepted: 4 November 2025

Abstract

This paper designs a new type of safety valve suitable for ultra-supercritical conditions and analyzes its flow field characteristics through numerical simulation. The safety valve features a valve seat design based on the Laval principle, ensuring that the steam velocity at the outlet reaches supersonic speeds, thereby enhancing discharge efficiency. Using CFX software, in conjunction with a turbulence model and steady-state simulation techniques, an in-depth analysis of the fluid characteristics within the valve was conducted. The results show that under different pressure levels and valve openings, fluid characteristics such as pressure distribution and Mach number exhibit consistency. At the valve outlet, a distinct supersonic flow region was observed, verifying the superior pressure relief capacity of this safety valve design.