In order to investigate the heat recovery boiler of steel smelting converters

a simple and reliable experimental system has been designed

and the investigation of hydrodynamic property for vertical natural circulation under impulse heat load has been carried out. The infuence of impulse heat load and under-enthalpy of working medium upon hydrodynamic property concerning vertical natural circulation has been analyzed

the general variational rule of hydrodynamic property having been obtained

and some recommendations for improving water circulation conditions of heat-recovery boiler for steel smelting converters having been put forward.