RÉSUMÉ

The paper describes the critical conditions for the functioning of the pump of heat action (PHA). They are determined by the heat flux in the evaporator that provides the equilibrium working condition of the pump at a given vapor pressure. This pressure depends on the hydraulic characteristics of the pump and the external contour and the boundary conditions in the zones of evaporation and condensation. Another condition is due to the cooling rate of the drained condenser-accumulator, which must be enough to exclude the possibility of a limit overheating temperature achievement in drained evaporator.