Patent Publication Number: US-2007095079-A1

Title: Power plant with motorless feed pump

Description:
Provisional application previously filed: This applicant respectfully claims the rights and advantages of a provisional application filed Nov. 1, 2004, under the same title. U.S. PTO # 17513 ,  60 / 623828 , Filed Nov. 1, 2004 The present application contains at least one claim specifically identical with that filed with the provisional application.  
    
    
     PARTS LIST  
     
         
           10  vaporizer  
           20  expansion engine  
           21  venturi device  
           22  converging/diverging nozzle  
           23  expander  
           30  electric generator  
           40  1 st  heatexchanger  
           41  2 nd  heat exchanger  
           42  3 rd  heat exchanger  
           50  1 st  valve  
           51  2 nd  valve  
           60  evaporator  
           80  thermal energy source  
           90  heat sink the working fluid feedpump, and prior to entry of working fluid into the boiler. Reheat, recuperated heat, and regenerated heat, extracted steam, and superheating are legitimate attempts to increase the net efficiency or net work of simple Rankine cycles by manipulating the heat content, temperature and pressure to one or more secondary turbines. These embodiments include a progression from simple Rankine cycles to so-called “reheat cycles” in which steam is extracted from various stages within a primary turbine, and the extracted steam is sent to a heat exchanger, recuperator, regenerator, and/or superheater where heat is added to the steam. The steam is variously directed to the boiler or to another turbine at a lower pressure than the primary turbine. The net efficiency and net work is usually higher than in a simple Rankine cycle. Reheat cycles are a feature in most modem steam and organic Rankine cycle power plants.  
       
    
      Simple Rankine cycle and reheat Rankine cycles all employ one or more working fluid feed pumps. In fact, all Rankine cycle style power plants, including those previously mentioned, and multiple working-fluid cycles as exemplified by ‘Kalina’ cycles, employ working fluid feed pumps to recycle working fluid to the boiler(s). Feed pumps require power to operate. Some feed pumps are powered by electric motors, others are powered by power output of a main turbine, and others are powered by a dedicated steam turbine. The present invention relates to a power cycle in which a spent working fluid is recycled without engine or motor power, nor with the use of a pump or steam injector.  
      All Rankine cycles, combined cycles, and cycles utilizing extraction steam, recuperation, regeneration, cycles utilizing a single working fluid, cycles in which more than one working fluids are combined, or combined and consequently separated, are cycles which require a fluid to be recycled by a working fluid feed pump. The present invention incorporable in all of the above named Rankine cycle embodiments where a condensed working fluid must be returned to a boiler, evaporator, vaporizer or heat exchanger for re-vaporization.  
     OBJECTS AND ADVANTAGES  
      It is an object of the present invention to provide an alternative method of operation for the cycling of a spent working fluid in a thermal power plant and to accomplish said recycling without the use of a compressive-type working-fluid feed pump, nor a high speed vapor impact ejector, nor any other type of mechanical working fluid feed pump.  
      In a portion of the present inventor&#39;s previously patented method (U.S. Pat. No. 5,685,152, U.S. Pat. No. 5,974,804), the condenser&#39;s liquefied working fluid was fed by gravity into a 1 st  valve leading into a heat exchanger. The 1 st  valve was closed, and a 2 nd  valve bled the liquid working fluid by gravity from the heat exchanger down into the vaporizer where it was heated. In the present invention, the condensed fluid is heated before it enters the vaporizer. In a portion of the present method, a 1 st  valve leading into a heat exchanger is opened through which enters a condensed fluid, the 1 st  valve is closed, the condensed fluid is heated to a predetermined temperature, a 2 nd  valve leading out of the heat exchanger is opened, the fluid exits the heat exchanger and enters the vaporizer where it is vaporized.  
     ADVANTAGE OF THE PRESENT METHOD  
      One advantage of the change in method, that is, by heating the condensed fluid in the 2 nd  heat exchanger before its passage through the 2 nd  valve on its way to the vaporizer, the heated condensed fluid now provides a high vapor pressure that assists the condensed vapor to fall into the vaporizer. This property eliminates the partial vacuum vapor lock that might otherwise prevent a low pressure fluid from falling by gravity through two vessels separated by a constrictive orifice (in this case, from the 2 nd  heat exchanger ( 41 ) through the 2 nd  valve ( 51 ) and into the vaporizer ( 10 )). In other words, it eliminates the need of high pressure vapor to rise upward from the vaporizer and pass through the valve in order to displace condensed vapor in the 2 nd  heat exchanger. The problem that is now avoided is similar in effect to holding water in a sipping straw with one&#39;s index finger covering the top of the straw. By eliminating the partial vacuum vapor lock (that is, by increasing the vapor pressure in the 2 nd  heat exchanger), we are, in effect, raising our finger from the top of the straw. The condensed working fluid falls by gravity into the vaporizer. True, the vapor lock can be avoided by proper design of the three components involved in the step, as has been demonstrated repeatedly by the inventor in the laboratory. However, the new method reduces the cost and size of the components greatly and adds flexibility of design to the further development of larger power plants.  
     PREFERRED EMBODIMENT  
      In one embodiment of the present invention, the energy conversion system includes: 
      a thermal energy source ( 80 ) in thermal communication with a vaporizer ( 10 ), and in thermal communication with a 2 nd  heat exchanger ( 41 );     a vaporizer ( 10 ) for vaporizing a thermal fluid at a high pressure having a vaporizer output supplying high pressure thermal fluid;     an expansion device ( 20 ) in fluid communication with said vaporizer output for expanding said high pressure thermal fluid and providing a low pressure thermal fluid at an output of said expansion device, said expansion device ( 20 ) also supplying useful mechanical power, and/or a refrigeration effect for cooling an enclosed space;     a 1 st  heat exchanger ( 40 ) in thermal communication with a thermal sink ( 90 ), and in fluid communication to said output of said expansion device ( 20 ) for cooling and condensing said low pressure thermal fluid, producing condensed thermal fluid, said 1 st  heat exchanger ( 40 ) also supplying a predetermined reserve capacity for receiving said condensed thermal fluid, said 1 st  heat exchanger ( 40 ) having an output controlled by a 1 st  valve ( 50 );     a 2 nd  heat exchanger ( 41 ) in thermal communication with a thermal sink ( 90 ) and with said thermal energy source ( 80 ), said 2 nd  heat exchanger ( 41 ) positioned and connected to 1 st  valve ( 50 ) to accept said condensed thermal fluid from said 1 st  heat exchanger ( 40 ) by gravity when said 1 st  valve ( 50 ) is opened, said 2 nd  heat exchanger ( 41 ) including at its output a 2 nd  valve ( 51 );     said vaporizer ( 10 ) positioned and connected to said 2 nd  valve ( 51 ) to accept said condensed thermal fluid by gravity from said 2 nd  heat exchanger ( 41 ) when said 2 nd  valve ( 51 ) is opened;     whereby said 1 st  valve ( 50 ), 2 nd  valve ( 51 ) and 2 nd  heat exchanger ( 41 ) may be operated to permit intermittent passage of said condensed thermal fluid from said 1 st  heat exchanger ( 40 ) to said vaporizer ( 10 ) without causing substantial reduction of pressure in said vaporizer ( 10 ), and without causing substantial increase of pressure in said 1 st  heat exchanger ( 40 ).    

     Method of Operation in the Preferred Embodiment  
      The method of operation of the preferred embodiment requires: 
      the directing of thermal energy from a thermal energy source ( 80 ) into a vaporizer ( 10 );     vaporizing a thermal fluid to provide a high pressure thermal fluid;     expanding said thermal fluid in an expansion device ( 20 ) to produce a low pressure thermal fluid and useful mechanical power and/or refrigeration effect to cool an enclosed space;     removing heat, condensing and accumulating said thermal fluid in a 1 st  heat exchanger ( 40 ) to provide an accumulated condensed thermal fluid;     passing, using gravity, said accumulated condensed thermal fluid through a 1 st  valve ( 50 ) to a 2 nd  heat exchanger ( 41 ) by opening said 1 st  valve ( 50 );     allowing a pre-determined volume of said condensed thermal fluid to enter said 2 nd  heat exchanger ( 41 );     closing said 1 st  valve ( 50 );     heating said condensed thermal fluid in said 2 nd  heat exchanger ( 41 ) to a pre-determined temperature;     opening a 2 nd  valve ( 51 );     passing said condensed thermal fluid from said 2 nd  heat exchanger ( 41 ) through said 2 nd  valve ( 51 ), using gravity, to said vaporizer ( 10 );     closing said 2 nd  valve ( 51 ); and     cooling the remaining non-condensed thermal fluid of said 2 nd  heat exchanger ( 41 ) until the pressure in said 2 nd  heat exchanger ( 41 ) is not substantially higher than the pressure of said condensed thermal fluid accumulating in said 1 st  heat exchanger ( 40 ).    

      The method is continuously repeatable, and provides non-stop operation of the expansion device for as long as a heat source is provided.  
      All thermodynamic cycles in which working fluid is pumped into a boiler, evaporator or vaporizer for recycling, including Rankine cycles, combined cycles, and cycles utilizing superheating, extraction steam, reheat, recuperated heat, regenerated heat, cycles utilizing a single working fluid, cycles in which more than one working fluids are combined or combined and consequently separated, can be modified to accommodate the method and apparatus described herein. In these cases, the conventional feed pumps would be replaced with 1 st  heat exchanger ( 40 ) acting solely as a receiver, 1 st  valve ( 50 ), 2 nd  heat exchanger ( 41 ), and 2 nd  valve ( 51 ), positioned serially and relative to gravity to accept condensed thermal fluid from said 1 st  heat exchanger/receiver ( 40 ) to 1 st  valve ( 50 ), to  2 n heat exchanger ( 41 ), to 2 nd  valve ( 51 ) to a boiler, evaporator or vaporizer.  
      The working fluid can consist of a single fluid, or more than one fluid.  
      The expansion engine ( 20 ) can be one, more than one, or a combination of reciprocating, turbine, expander, scroll expander, screw expander, or any type of expansion engines.  
      The expansion engine can be connected to an electric generator ( 30 ), a refrigeration compressor ( 30 ), a water pump ( 30 ), or any other device which converts rotational power produced by the expansion engine into a useful product or function.  
      The expansion engine ( 20 ) can be used to provide a low temperature exhaust for the purpose of producing a refrigeration effect for the cooling of an enclosed space. One example is the use of expanders to produce an artificially low temperature exhaust condition for the separation or condensation of vaporous petroleum raw materials. In such a case, the rotational power is not the desired product. Rather, the temperature reduction is key. Similarly in the present embodiment, an expander can be used as an expansion device for the purpose of producing the artificial low temperature condition, which will then be used for cooling an enclosed space.  
      A venturi device, often referred to as an ejector or eductor, as are known to the art, can be substituted in place of an expansion engine of the first embodiment in order to produce a suction pressure in an evaporator. The 1 st  heat exchanger or the 2 nd  heat exchanger can feed liquefied condensate to the evaporator. The resulting evaporation from the evaporator will produce a refrigeration effect in the evaporator for cooling an enclosed space. Similarly, a converging/diverging nozzle, as is known to the art, similar to the converging/diverging nozzle of a venturi device but without the presence of both said evaporator and said suction pressure input, will produce a refrigeration effect at the nozzle output. The nozzle output, in thermal communication with an enclosed space, will serve as a heat sink for cooling an enclosed space.  
      The 1 st  heat exchanger ( 40 ) removes thermal energy from the working fluid, condenses the working fluid to its liquid state, and if so equipped, recuperates heat energy removed from the spent working fluid. The 2 nd  heat exchanger ( 41 ) also removes thermal energy from the working fluid, also condenses the working fluid to its liquid state, and if so equipped, recuperates heat energy removed from the spent working fluid.  
      Under certain conditions, heat exchanger ( 40 ) becomes a receiver ( 40 ), and may not require thermal communication with a thermal heat sink.  
      A thermal heat sink may be any of the type known to the art. The atmosphere itself is a thermal heat sink, just as the water, ice, snow and earth absorb thermal energy at temperatures higher than themselves. Equipment known to the art and industry may be used to facilitate the action of the heat sink in removing heat from 1 st  and 2 nd  heat exchangers. Artificially produced heat sinks may be employed to store potential heat sink properties for use at a later time.  
      Notwithstanding the three embodiments herein presented, an astute observer should conclude that a combination of the embodiments is easily accomplished. Such a combination would, for example combine an electric power plant with a refrigeration unit. Other combinations can include a refrigeration unit, an air conditioning unit, an electric generator, a water pump, an irrigation pump, an electrolysis unit for the production of hydrogen, and other uses known to the art.  
     Second Embodiment—Venturi  
      In a second embodiment of the present invention, the energy conversion system includes: 
      thermal energy source ( 80 ) in thermal communication with a vaporizer ( 10 ), and in thermal communication with a 2 nd  heat exchanger ( 41 );     a vaporizer ( 10 ) for vaporizing a thermal fluid at a high pressure having a vaporizer output supplying high pressure thermal fluid;     a venturi device ( 21 ) in fluid communication with said vaporizer output for expanding said high pressure thermal fluid, said venturi device ( 21 ) having a low pressure venturi output supplying a low pressure thermal fluid, said venturi device ( 21 ) also having a venturi suction input supplying a suction pressure;     an evaporator ( 60 ) in fluid communication with said venturi suction input for producing a refrigeration effect for cooling an enclosed space, said evaporator ( 60 ) having an evaporator input for receiving liquefied working fluid;     a 1 st  heat exchanger ( 40 ) in thermal communication with a thermal sink ( 90 ), said 1 st  heat exchanger ( 40 ) in fluid communication with said low pressure venturi output, for cooling and condensing said low pressure thermal fluid, producing condensed thermal fluid, said 1 st  heat exchanger ( 40 ) also supplying a predetermined reserve capacity for receiving said condensed thermal fluid, said 1 st  heat exchanger ( 40 ) having an output controlled by a 1 st  valve ( 50 ), said 1 st  heat exchanger ( 40 ) having a 2 nd  output in fluid communication with said evaporator input for supplying a portion of said condensed thermal fluid to said evaporator ( 60 );     a 2 nd  heat exchanger ( 41 ) in thermal communication with a thermal sink ( 90 ) and with said thermal energy source ( 80 ), said 2 nd  heat exchanger ( 41 ) positioned to accept said condensed thermal fluid from said 1 st  heat exchanger ( 40 ) by gravity when said 1 st  valve ( 50 ) is opened, said 2 nd  heat exchanger ( 41 ) including at its output a 2 nd  valve ( 51 );     said vaporizer ( 10 ) positioned and connected to said 2 nd  valve ( 51 ) to accept said condensed thermal fluid by gravity from said 2 nd  heat exchanger ( 41 ) when said 2 nd  valve ( 51 ) is opened;     whereby said 1 st  valve ( 50 ), said 2 nd  heat exchanger ( 41 ) and said 2 nd  valve ( 51 ) may be operated to permit intermittent passage of said condensed thermal fluid from said 1 st  heat exchanger ( 40 ) to said vaporizer ( 10 ) without causing substantial reduction of pressure in said vaporizer ( 10 ), and without causing substantial increase of pressure in said 1 st  heat exchanger ( 40 ).    

     Method of Operation in the Second Embodiment  
      The method of operation in the second embodiment requires: 
      the directing of thermal energy from a thermal energy source ( 80 ) into a vaporizer ( 10 );     vaporizing a thermal fluid to provide a high pressure thermal fluid; expanding said thermal fluid in a venturi device ( 21 ) to produce a suction pressure in an evaporator ( 60 ), said suction pressure causing the evaporation of working fluid in said evaporator ( 60 ) resulting in a refrigeration effect in said evaporator ( 60 ) useful for cooling an enclosed space, said venturi device ( 21 ) also producing a low pressure thermal fluid;     removing heat, condensing and accumulating said low pressure thermal fluid in a 1 st  heat exchanger ( 40 ) to provide an accumulated condensed thermal fluid;     passing a portion of said condensed thermal fluid to said evaporator ( 60 );     intermittently passing, using gravity, said accumulated condensed thermal fluid through a 1 st  valve ( 50 ) to a 2 nd  heat exchanger ( 41 ) by opening said 1 st  valve ( 50 );     allowing a pre-determined volume of said condensed thermal fluid to enter said 2 nd  heat exchanger ( 41 );     closing said 1 st  valve ( 50 );     heating said condensed thermal fluid in said 2 nd  heat exchanger ( 41 ) to a pre-determined temperature;     opening a 2 nd  valve ( 51 );     passing said condensed thermal fluid from said 2 nd  heat exchanger ( 41 ) through said 2 nd  valve ( 51 ), using gravity, to said vaporizer ( 10 );     closing said 2 nd  valve ( 51 ); and     cooling the remaining non-condensed thermal fluid of said 2 nd  heat exchanger ( 41 ) until the pressure in said 2 nd  heat exchanger ( 41 ) is not substantially higher than the pressure of said condensed thermal fluid accumulating in said 1 st  heat exchanger ( 40 ).    

      The method is continuously repeatable, and provides non-stop operation of the venturi device for as long as a heat source is provided.  
     Third Embodiment—Converging/Diverging Nozzle  
      In a third embodiment of the present invention, the energy conversion system includes: 
      a thermal energy source ( 80 ) in thermal communication with a vaporizer ( 10 ), and in thermal communication with a 2 nd  heat exchanger ( 41 );     a vaporizer ( 10 ) for vaporizing a thermal fluid at a high pressure having a vaporizer output supplying high pressure thermal fluid;     a converging/diverging nozzle ( 22 ) in fluid communication with said vaporizer output for expanding said high pressure thermal fluid and providing a low pressure thermal fluid at a converging/diverging nozzle output, said converging/diverging nozzle ( 22 ) producing a high speed low pressure thermal fluid at a temperature below that of the ambient temperature at said converging/diverging nozzle output;     a 3 rd  heat exchanger ( 42 ) in fluid communication with said nozzle output for cooling an enclosed space, said 3 rd  heat exchanger ( 42 ) having a 3 rd  heat exchanger output;     a 1 st  heat exchanger ( 40 ) in thermal communication with a thermal sink ( 90 ), said 1 st  heat exchanger ( 40 ) in fluid communication with said 3 rd  heat exchanger output for cooling and condensing said low pressure thermal fluid, producing condensed thermal fluid, said 1 st  heat exchanger ( 40 ) also supplying a predetermined reserve capacity for receiving said condensed thermal fluid, said 1 st  heat exchanger ( 40 ) having an output controlled by a 1 st  valve ( 50 );     a 2 nd  heat exchanger ( 41 ) in thermal communication with a thermal sink ( 90 ) and with said thermal energy source ( 80 ), said 2 nd  heat exchanger ( 41 ) positioned to accept said condensed thermal fluid from said 1 st  heat exchanger ( 40 ) by gravity when said 1 st  valve ( 50 ) is opened, said 2 nd  heat exchanger ( 41 ) including at its output a 2 nd  valve ( 51 );     said vaporizer ( 10 ) positioned and connected to said 2 nd  valve ( 51 ) to accept said condensed thermal fluid by gravity from said 2 nd  heat exchanger ( 41 ) when said 2 nd  valve ( 51 ) is opened;     whereby said 1 st  valve ( 50 ), 2 nd  heat exchanger ( 41 ) and 2 nd  valve ( 51 ) may be operated to permit intermittent passage of said condensed thermal fluid from said 1 st  heat exchanger ( 40 ) to said vaporizer ( 10 ) without causing substantial reduction of pressure in said vaporizer ( 10 ), and without causing substantial increase of pressure in said 1 st  heat exchanger ( 40 ).    

     Method of Operation in the Third Embodiment  
      The method of operation in the third embodiment requires: 
      directing thermal energy from a thermal energy source ( 80 ) into a vaporizer ( 10 );     vaporizing a thermal fluid to provide a high pressure thermal fluid;     first accelerating, then expanding said high pressure thermal fluid through a converging/diverging nozzle ( 22 ),said converging/diverging nozzle ( 22 ) producing a low pressure thermal fluid exhibiting a temperature below that of the ambient temperature;     passing said low temperature thermal fluid through a 3 rd  heat exchanger ( 42 ) resulting in a refrigeration effect in 3 rd  heat exchanger ( 42 ) for cooling an enclosed space;     condensing and accumulating said low pressure thermal fluid in a 1 st  heat exchanger ( 40 ) to provide an accumulated condensed thermal fluid;     intermittently passing, using gravity, said accumulated condensed thermal fluid through a 1 st  valve ( 50 ) to a 2 nd  heat exchanger ( 41 ) by opening said 1 st  valve ( 50 );     allowing a pre-determined volume of said condensed thermal fluid to enter said 2 nd  heat exchanger ( 41 );     closing said 1 st  valve ( 50 );     heating said condensed thermal fluid in said 2 nd  heat exchanger ( 41 ) to a pre-determined temperature;     opening a 2 nd  valve ( 51 );     passing said condensed thermal fluid from said 2 nd  heat exchanger ( 41 ) through said 2 nd       valve ( 51 ), using gravity, to said vaporizer ( 10 );     closing said 2 nd  valve ( 51 ); and     cooling the remaining non-condensed thermal fluid of said 2 nd  heat exchanger ( 41 ) until the pressure in said 2 nd  heat exchanger ( 41 ) is not substantially higher than the pressure of said condensed thermal fluid accumulating in said 1 st  heat exchanger ( 40 ).    

      The method is continuously repeatable, providing continual operation of the expansion device.  
     Fourth Embodiment—Expander  
      In a fourth embodiment of the present invention, the energy conversion system includes: 
      a thermal energy source ( 80 ) in thermal communication with a vaporizer ( 10 ), and in thermal communication with a 2 nd  heat exchanger ( 41 );     a vaporizer ( 10 ) for vaporizing a thermal fluid at a high pressure having a vaporizer output supplying high pressure thermal fluid;     an expander ( 23 ), a turbine-like device for producing a low temperature in a thermal fluid, in fluid communication with said vaporizer output for expanding said high pressure thermal fluid and providing a low pressure thermal fluid at an expander output, said expander ( 23 ) producing a high speed low pressure thermal fluid at a temperature below that of the ambient temperature at said expander output;     a 3 rd  heat exchanger ( 42 ) in fluid communication with said expander output for cooling an enclosed space, said 3 rd  heat exchanger ( 42 ) having a 3 rd  heat exchanger output;     a 1 st  heat exchanger ( 40 ) in thermal communication with a thermal sink ( 90 ), said 1 st  heat exchanger ( 40 ) in fluid communication with said 3 rd  heat exchanger output for cooling and condensing said low pressure thermal fluid, producing condensed thermal fluid, said 1 st  heat exchanger ( 40 ) also supplying a predetermined reserve capacity for receiving said condensed thermal fluid, said 1 st  heat exchanger ( 40 ) having an output controlled by a 1 st  valve ( 50 );     a 2 nd  heat exchanger ( 41 ) in thermal communication with a thermal sink ( 90 ) and with said thermal energy source ( 80 ), said 2 nd  heat exchanger ( 41 ) positioned to accept said condensed thermal fluid from said 1 st  heat exchanger ( 40 ) by gravity when said 1 st  valve ( 50 ) is opened, said 2 nd  heat exchanger ( 41 ) including at its output a 2 nd  valve ( 51 );     said vaporizer ( 10 ) positioned and connected to said 2 nd  valve ( 51 ) to accept said condensed thermal fluid by gravity from said 2 nd  heat exchanger ( 41 ) when said 2 nd  valve ( 51 ) is opened;     whereby said 1 st  valve ( 50 ), 2 nd  heat exchanger ( 41 ) and 2 nd  valve ( 51 ) may be operated to permit intermittent passage of said condensed thermal fluid from said 1 st  heat exchanger ( 40 ) to said vaporizer ( 10 ) without causing substantial reduction of pressure in said vaporizer ( 10 ), and without causing substantial increase of pressure in said 1 st  heat exchanger ( 40 ).    

     Method of Operation in the Fourth Embodiment  
      The method of operation in the fourth embodiment requires: 
      directing thermal energy from a thermal energy source ( 80 ) into a vaporizer ( 10 );     vaporizing a thermal fluid to provide a high pressure thermal fluid;     first accelerating, then expanding said high pressure thermal fluid through an expander ( 23 ), said expander ( 23 ) producing a low pressure thermal fluid exhibiting a temperature below that of the ambient temperature;     passing said low temperature thermal fluid through a 3 rd  heat exchanger ( 42 ) resulting in a low temperature in 3 rd  heat exchanger ( 42 ) for cooling an enclosed space;     condensing and accumulating said low pressure thermal fluid in a 1 st  heat exchanger ( 40 ) to provide an accumulated condensed thermal fluid;     intermittently passing, using gravity, said accumulated condensed thermal fluid through a 1 st  valve ( 50 ) to a 2 nd  heat exchanger ( 41 ) by opening said 1 st  valve ( 50 );     allowing a pre-determined volume of said condensed thermal fluid to enter said 2 nd  heat exchanger ( 41 );     closing said 1 st  valve ( 50 );     heating said condensed thermal fluid in said 2 nd  heat exchanger ( 41 ) to a pre-determined temperature;     opening a 2 nd  valve ( 51 );     passing said condensed thermal fluid from said 2 nd  heat exchanger ( 41 ) through said 2 nd  valve ( 51 ), using gravity, to said vaporizer ( 10 );     closing said 2 nd  valve ( 51 ); and     cooling the remaining non-condensed thermal fluid of said 2 nd  heat exchanger ( 41 ) until the pressure in said 2 nd  heat exchanger ( 41 ) is not substantially higher than the pressure of said condensed thermal fluid accumulating in said 1 st  heat exchanger ( 40 ).    

      The method is continuously repeatable, providing continual operation of the expansion device.  
    
    
     A BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       FIG. 1  is a block diagram of a the first embodiment of the energy conversion system of the present invention.  FIG. 1  includes a heat engine whose function is to provide rotational power to one or more implements such as a generator, pump, compressor, actuator, cutter, and other tools that convert rotational power into a useful product such as electricity, irrigation, pumping, compressing, refrigerating, moving, powering, or any other product of the conversion of rotational power.  
       FIG. 2  depicts a block diagram of a thermodynamic cycle including a venturi device for producing a vacuum effect above a contained refrigerant, affecting a refrigeration effect in a closed space.  
       FIG. 3  depicts a block diagram of a thermodynamic cycle including a convergent-divergent nozzle for producing a refrigeration effect in a closed space.  
       FIG. 4  depicts a block diagram of a thermodynamic cycle including a turbo-expander for producing a refrigeration effect in a closed space.  
    
    
      The inventor has no patent attorney, and requests, if allowed, that the examiner propose claims as he or she may deem fit to best protect the inventor&#39;s proprietary interests. Thank you.