Abstract: Background: Steam flow limiter is an important device of steam generator in nuclear power plant. It limits the steam flow during the event of steam line break. However, it is required that the steam flow limiter has low pressure loss during normal operation of steam generator. Purpose: The aim is to design a steam flow limiter with lower pressure loss. Methods: An improved design of steam flow limiter is developed by increasing the number of Venturies from 7 to 19. Two test models of steam flow limiters of traditional design and improved design are tested. Results: The pressure loss factor of the traditional design test model is 6.9. The pressure loss factor of the improved design test model is 4.4. Conclusion: Based on the same total throat flow area, it is verified by tests that the pressure loss of steam flow limiter containing 19 Venturis is significantly lower than that containing 7 Venturis. The pressure loss calculation method is verified simultaneously.

Key words: Steam generator, Steam flow limiter, Venturi, Pressure loss