Structural design and two-phase flow stability test for the steam generator

This paper describes the structural designs and the two-phase flow stability test for the steam generator of the 10 MW high temperature gas-cooled reactor test module. The sectionalized heat transfer surface of the steam generator is made up of modules formed by series-connected single cylindrical coils wound around a displacer. Such a heating surface has some advantages as compared with a heating surface formed by multi concentric coils with a great diameter of winding (Proceeding of the International ANS/ENS Topical Meeting on Thermal Reactor Safety (1986); Progress of HTGR Process Heat Application Study (1994); Heat Transfer-Soviet Res. 22 (1990)). It plays an important part in the design of the integrated steam generator. Since it is a once-through steam generator and operates at a medium pressure (4.0 MPa), two-phase flow instabilities are a difficult problem (Functional Performance of the Helical Coil SG CNSG-IV System (1975)). The design must eliminate two-phase flow instabilities and the system must be tested to show that flow instability does not occur.