Heat-activated multiphase fluid-operated pump

A heat-activated multiphase fluid-operated pump, comprising:

• a hot chamber containing a working fluid and receptive of externally applied heat to convert the working fluid into vapor;
• a pressure-control safety valve coupled to an exit port of the hot chamber and maintaining the working fluid in the hot chamber at a set target pressure and allowing vaporized working fluid to escape through the exit port whenever the target pressure is exceeded;
• a liquid-piston chamber coupled to the pressure-control safety valve to receive vaporized working fluid from the hot chamber at the target pressure, the vaporized working fluid expanding adiabatically and displacing liquid within the liquid-piston chamber, expelling it therefrom in a pumping stage of a thermodynamic cycle;
• a unidirectional pump-exit check valve coupled to an exit port of the liquid-piston chamber to allow the displaced liquid to exit the liquid-piston chamber;
• a unidirectional liquid suction-entry check valve coupled to a return port of the liquid-piston chamber;
• a condenser coupled to the pump-exit and suction-entry check valves to receive displaced liquid and allow it to return to the liquid-piston chamber in a suction stage of the thermodynamic cycle;
• and
• a unidirectional vapor-injector return check valve coupled to both an exit port of the liquid-piston chamber and to an input port of the hot chamber, wherein periodic pressure pulses from the liquid-piston chamber that temporarily exceed the pressure in the hot chamber facilitate jets of condensed fluid to return in successive brief spurts.