[en] The critical heat flux (CHF) is studied in the conditions where the fluid fed to heated tubes is subcooled (including saturated liquid in the extreme situation) with no entrained vapor. Postulating that there is a state where the hydrodynamic condition is responsible for CHF, a theoretical presumption for the generalized correlation equation of CHF is attempted with the aid of vectorial dimensional analysis. Experimental data of CHF obtained from the literature for fluids of seven different kinds are then analyzed, revealing the existence of four characteristic regimes of CHF, called here L-, H-, N-, and HP-regimes, and leading to the development of the generalized correlation of CHF data as well as that of CHF-regime correlation. (author)