Heat engine using a liquid-vapor-phase-changing material

A method for converting heat into work, comprising:

• vaporizing or bringing a liquid vapor phase-changing material (LVPhC), selected from a list consisting of:
• pentane, isobutane, propane, R134a, R245fa, fluorocarbons and toluene or any vapors used in organic Rankine Cycle (ORC) technology, from a liquid phase to a vapor phase or a supercritical phase at a temperature of about T1 and a pressure of about P1 and mixing it in a nozzle with a heat transfer liquid (HTL) having a temperature of about T1 and a pressure of about P1, wherein the LVPhC is at a liquid phase below a temperature of about TO in pressure of about P1, wherein TO is lower than T1, thereby resulting in a quasi-isothermal expansion, while reducing the pressure to P0, causing an acceleration of the HTL/LVPhC mixture;
• and
• ejecting the accelerated HTL/LVPhC mixture through a nozzle for converting its kinetic energy into work and collecting the LVPhC and the HTL at a pressure of P0;
• wherein said nozzle is connected to or part of a reaction turbine;
• wherein the method further comprises following said collecting:
• heating at least a portion of the HTL to a temperature of about T1 and increasing its pressure to a pressure P1 to allow an additional cycle of said mixing.

A system for converting heat into work, comprising:

• an evaporator for receiving a liquified vapor phase-changing material (LVPhC), selected from a list consisting of:
• pentane, isobutane, propane, R134a, R245fa, fluorocarbons and toluene or any vapors used in organic Rankine Cycle (ORC) technology, and vaporizing it or bringing to a vapor phase or a supercritical phase at a pressure of about P1 and a temperature of about T1;
• a heating volume for heating heat transfer liquid (HTL) to a temperature of about T1;
• a HTL pump for increasing pressure of said HTL to a pressure of about said P1;
• a nozzle in fluid communication with the HTL pump and the evaporator and having an inlet portion for receiving said HTL and a mixing portion for (i) allowing mixing said HTL at about said temperature T1 and at about said pressure P1 with said LVPhC at a vapor phase and (ii) allowing said mixture to undergo isothermal expansion to a pressure of about P0 lower than said pressure P1, thereby causing acceleration of said mixture at said nozzle towards an outlet of the nozzle;
• a reaction turbine configured for rotation in result to the acceleration of said mixture, thereby converting the kinetic energy of the mixture to work, wherein the nozzle is coupled to or part of the reaction turbine;
• and
• a separation unit for separating the ejected HTL and the vaporized LVPhC, said separation unit comprises a collection unit to collect the ejected HTL and to allow to direct it to either the heating volume, the HTL pump, the nozzle, the evaporator or any combination thereof;
• wherein the collection unit defines a drain for accumulating the separated HTL, and the HTL is suctioned from the drain into the nozzle in result to the operation of the reaction turbine, thereby constituting said HTL pump, wherein the suctioning causes the HTL to enter the nozzle at a pressure of about P1.