A lumped parameter dynamic model of the helical coiled once-through steam generator with movable boundaries

A lumped parameter mathematical model of the helical coiled once-through steam generator of the 10 MW high-temperature gas-cooled reactor (HTR-10) is developed based upon the fundamental conservation of fluid mass, energy, and momentum. The steam generator is handled with single tube concept and is divided into three regions as subcooled region, boiling region, and superheater region. And these regions have movable boundaries to simulate the change of the region lengths. A lot of numerical experiments are investigated using the developed model. The steady-state simulation results agree well with the design data. The transient simulation results show that the model can properly predict the steam generator dynamics.